DR1: Acta Chir Iugosl. 2003;50(3):121-4. Medullary thyroid carcinoma. Genetic screening and prophylactic thyroidectomies. Bergant D, Hocevar M. Institute of Onkology, Ljubljana, Slovenia. Medullary thyroid cancer is a rare, neuroendocrine, tumor. It arises from parafollicular or C-cells with the ability to produce and secrete different bioactive substances like calcitonin (TC) and CEA (1-5) TC is ideal tumor marker in early diagnosis, in patents' follow up and in evaluation of their treatment. TC determinations after ca/pentagastrine stimulation test give us even more accurate results and the procedure is used for biochemical family screening. MTC occurs as a sporadic tumor or in hereditary settings MEN 2A, MEN 2B and FMCT. Germ/line point mutations in RET proto/onkogene are responsible for tumor arise and inheritance of settings. Genetic screening provides information of these RET mutations in family members even before pathologic changes occur. These individuals with MEN 2A, 2B and FMCT characteristic RET mutations are almost certain to acquire MTC (95% penetrance) in their lives and are candidates for preventive total thyroidectomy (TT), with or without central neck dissection (CND). Surgery is still the treatment of choice for MTC and only C-cell hyperplasia and early stage of MTC can be cured. Prophylactic thyroid surgery eliminates the possibility of MTC but doesn't influence appearance of other diseases (PHEO, HPTH) of MEN 2 syndromes. PMID: 15179767 [PubMed - indexed for MEDLINE] DR2: Acta Chir Iugosl. 2003;50(3):51-5. [Current opinion on the etiology of differentiated thyroid carcinoma] [Article in Croatian] Han R. Institut za nuklearnu medicinu, KCS, Beograd. It is apparent that in the last decade carcinoma of the thyroid is becoming increasingly prevalent. The multistage complex theory of thyroid carcinogenesis is based on observations made on cohort patients studies and during animal experiments over a period of last fifty years. The process of thyroid oncogenesis is conceived to be a series of events induced by genetic and environmental factors which alter follicular cells division and growth control. These factors can be considered as initiators (chemical agents and ionising radiation) and promoters (some goitrogenes and drugs). The first class of factors induce incipient tumorigenesis while the second augments TSH secretion and radically increases tumour growth. Normally silent, intracellular proto-oncogenes (of which Ret/PTC series are the most conceived ones) can become activated by chromosomal translocations, deletions or mutations and can transform normal follicular cell into a condition of uncontrolled division and growth. The most significant known cause of thyroid carcinomas in men is exposure to external or internal ionising radiation. Beside that, long-term iodine deficiency, effects of certain chemical carcinogens, drugs and goitrogenes must be considered as significant risk factors. Possible role of sodium/iodide symporter is becoming an objective of the most recent investigations. Publication Types: Review Review, Tutorial PMID: 15179755 [PubMed - indexed for MEDLINE] DR3: Tumori. 2003 Sep-Oct;89(5):563-5. Diagnostic procedures in the follow-up of patients affected by MEN type 2. Seregni E, Pallotti F, Mattavelli F, Ferrari L, Martinetti A, Aliberti G, Villano C, Castellani MR, Bombardieri E. Division of Nuclear Medicine, National Cancer Institute, Milan, Italy. Multiple endocrine neoplasia type 2 (MEN 2) is an inherited disease caused by germline mutations in the RET proto-oncogene. The most distinctive MEN 2 variants are MEN 2A, MEN 2B and familial medullary thyroid cancer (FMTC). The hallmark of these syndromes is the development of medullary thyroid carcinoma (MTC), which occurs in almost all patients with MEN 2 syndromes. Other endocrinopathies are variably expressed. Pheochromocytoma and hyperparathyroidism occur in patients with MEN 2A with a frequency of about 50% and 30%, respectively. In this paper we summarize the most relevant diagnostic methods to detect and monitor MTC, pheochromocytoma and hyperparathyroidism. Publication Types: Review Review, Tutorial PMID: 14870788 [PubMed - indexed for MEDLINE] NR4: Tumori. 2003 Sep-Oct;89(5):553-5. Prophylactic thyroidectomy in MEN 2A syndrome. Mattavelli F, Seregni E, Collini P, Pasini B, Aiello A, Barbaccia C, Bimbi G, Riccio S, Santamaria S. Department of Head and Neck Surgery, National Cancer Institute, Milan, Italy. Genetic testing is the appropriate procedure in MEN 2A syndrome for the early diagnosis of medullary carcinoma even at a preclinical stage. Prophylactic total thyroidectomy represents the standard preventive and therapeutic surgical approach in the treatment of medullary thyroid carcinoma in MEN 2A syndrome. Our experience has confirmed the presence of CCH and medullary thyroid carcinoma even in clinically negative patients, in agreement with reports in the literature. PMID: 14870785 [PubMed - indexed for MEDLINE] DR5: Tumori. 2003 Sep-Oct;89(5):550-2. RETMEN2A and RETMEN2B oncoproteins are targets of PP1 inhibitor. Bongarzone I, Carniti C, Perego C, Mondellini P, Pierotti MA. Department of Experimental Oncology, National Cancer Institute, Milan, Italy. italia.bongarzone@istitutotumori.mi.it Medullary thyroid carcinoma (MTC) responds very poorly to chemotherapy. Mutations in the RET gene are critical for MTC pathogenesis. RET therefore represents a rational target for the development of novel MTC therapies. The accumulation of evidence from laboratory studies strongly suggests that PP1 inhibitor is a cytostatic agent for cells expressing RET oncoproteins. PP1 functions as a potent and selective inhibitor of RET oncoprotein phosphorylation, promoting its proteasomal degradation. Publication Types: Review Review, Tutorial PMID: 14870784 [PubMed - indexed for MEDLINE] NR6: Endocr Pract. 2003 Nov-Dec;9(6):570. Visual vignette. Multiple endocrine neoplasia type 2A (MEN2A) associated with cutaneous lichen amyloidosis. Bonbassei GJ. Endocrine and Diabetes Center of Western Connecticut, Danbury, USA. Publication Types: Case Reports PMID: 14758805 [PubMed - indexed for MEDLINE] NR7: Endocr Pathol. 2003 Winter;14(4):375-82. Long-term follow up of a "sporadic" unilateral pheochromocytoma revealing multiple endocrine neoplasia MEN2A-2 in an elderly woman. Weinhausel A, Behmel A, Ponder BA, Haas OA, Niederle B, Gessl A, Vierhapper H, Pfragner R. CCRI St. Anna Children's Hospital, Vienna, Austria. A unilateral, apparently sporadic pheochromocytoma was removed from the right adrenal of a 73-yr-old Caucasian woman. At the time of surgery, germline DNA from the patient was not available. However, a continuous cell line (KNA) established from the tumor showed a heterozygous sequence variant TGC (cysteine) to TGG (tryptophan) in exon 10, codon 611 of the RET proto-oncogene. Subsequent genetic testing of the patient and her offspring revealed the same base-change in herself, one daughter, one son, and the only grandson, confirming hereditary disease classified as MEN2A-2. Clinical follow up of the patient revealed elevated serum calcitonin after 6 yr. Thyroidectomy was performed and revealed a small medullary thyroid carcinoma. The patient's children thus far show no evidence of MEN2, but C-cell hyperplasia has been diagnosed in the grandson. Our serendipitous finding of a MEN2A-2 mutation in a patient with initial diagnosis of late onset, unilateral, "sporadic" pheochromocytoma would argue for routine mutation screening of even elderly patients presenting with a pheochromocytoma. Publication Types: Case Reports Review Review of Reported Cases PMID: 14739494 [PubMed - indexed for MEDLINE] DR8: Endocr Pathol. 2003 Winter;14(4):351-61. Ret protein expression in adrenal medullary hyperplasia and pheochromocytoma. Powers JF, Brachold JM, Tischler AS. Department of Pathology, Tufts-New England Medical Center, 750 Washington Street, Boston, MA 02111, USA. jpowers1@tufts-nemc.org Ret is a developmentally regulated tyrosine kinase involved in formation and maintenance of the nervous system. Ret mutations predisposing to pheochromocytomas and medullary thyroid carcinomas occur in multiple endocrine neoplasia (MEN) syndromes 2A and 2B. Biochemical studies have demonstrated overexpression of Ret mRNA and protein in pheochromocytomas compared to normal adrenal medulla. However, the cellular distribution of Ret in the normal human adrenal and in hyperplastic lesions that antecede pheochromocytomas are unclear. The present investigation was undertaken to resolve the histological distribution of Ret in the normal human adrenal, in pheochromocytomas evolving from adrenal medullary hyperplasia in MEN2A and in sporadic pheochromocytomas. Ret expression was studied by immunohistochemistry using both a polyclonal and a monoclonal antibody, with confirmation by immunoblotting of representative cases. Only occasional cells stained for Ret in the normal adrenal, consistent with the distribution in adult adrenals of other species. Heterogeneous, progressively increased Ret expression was observed during the evolution of pheochromocytomas. In both normal and neoplastic adrenal, the most intense immunoreactivity was observed in cells with neuron-like features. Our finding that Ret is not expressed at high levels in the early stages of disease suggests that elucidation of mechanisms that regulate Ret expression is required for understanding the pathobiology of MEN2A. The association of high-level Ret expression with neuronal morphology suggests that the variable overexpression of Ret in pheochromocytomas might in part be an epiphenomenon, reflecting the known phenotypic plasticity of these tumors. PMID: 14739491 [PubMed - indexed for MEDLINE] DR9: Surgery. 2003 Dec;134(6):1029-36; discussion 1036-7. When should thyroidectomy be performed in familial medullary thyroid carcinoma gene carriers with non-cysteine RET mutations? Niccoli-Sire P, Murat A, Rohmer V, Gibelin H, Chabrier G, Conte-Devolx B, Visset J, Ronceray J, Jaeck D, Henry JF, Proye C, Carnaille B, Kraimps JL; Groupe D'etude Des Tumeurs Endocrines. Department of Endocrinology and Endocrine Surgery, CHU Timone, 254 rue St Pierre, F 13385 Marseille cedex 05, France. BACKGROUND: Once familial medullary thyroid carcinoma gene carrier status is established, thyroidectomy must be performed in infancy for mutations in exon 10, but in familial medullary thyroid carcinoma with non-cysteine RET mutations, which is characterized by a late onset of C-cell disease, the appropriate timing of thyroidectomy is unclear. METHODS: We analyzed the cases of 76 patients who underwent thyroidectomy (mean age, 35.2 years); 66 patients underwent concomitant lymphadenectomy. RESULTS: Before the operation, 35 patients had abnormal basal calcitonin levels. Nine and 30 patients had negative or positive pentagastrin test results, respectively. We found normal thyroid in 4% of the patients, C-cell hyperplasia in 29% of the patients, medullary thyroid carcinoma in 67% of the patients (microscopic in 82.4%), and nodal metastases in 19.6% of the patients. The aggressiveness of the disease varied significantly between those patients with preoperative positive pentagastrin test results and those patients with high basal calcitonin levels, with a surgical cure rate of 60% and 34.3%, respectively. All patient who did not achieve cure had high basal preoperative calcitonin levels, which were related to macroscopic medullary thyroid carcinoma and nodal metastases in 5 of 9 patients. CONCLUSION: Thyroidectomy should not be delayed until basal calcitonin level becomes abnormal, at which time advanced disease may be present. As soon as the pentagastrin stimulation test becomes abnormal, operation should be undertaken on early staged disease to achieve cure for the patient. When performed while pentagastrin stimulation test is still negative, thyroidectomy may be truly prophylactic and should be recommended at 5 to 6 years. PMID: 14668737 [PubMed - indexed for MEDLINE] DR10: Anticancer Res. 2003 Sep-Oct;23(5A):3601-6. RET tyrosine kinase and medullary thyroid cells are unaffected by clinical doses of STI571. Skinner MA, Safford SD, Freemerman AJ. Department of Surgery, Duke University, Durham, NC 27710, USA. BACKGROUND: Activating mutations in the RET receptor tyrosine kinase are responsible for the development of medullary thyroid cancer (MTC) in persons with Multiple Endocrine Neoplasia type 2. We hypothesized that STI571 (Gleevec) would inhibit RET kinase and be a useful agent in the treatment of MTC. MATERIALS AND METHODS: We determined the IC50 of STI571 for RET using an in vitro kinase assay and also examined the effects of STI571 on cellular proliferation and viability in TT cells, a human MTC cell line. RESULTS: The average in vitro IC50 of STI571 for RET is 37 microM +/- 4 microM. Additionally, TT cells incubated with 10 microM STI571 for up to 8 days showed no apparent reduction in cell proliferation or viability. Higher concentrations of STI571, from 25 to 100 microM, induced necrosis of TT cells. CONCLUSION: The concentrations of STI571 required to significantly inhibit RET and to inhibit TT cell proliferation are not clinically achievable. We conclude that STI571 is not likely to be an effective treatment for MTC. PMID: 14666655 [PubMed - indexed for MEDLINE] DR11: Minerva Chir. 2003 Dec;58(6):801-9. [Treatment of familial medullary thyroid carcinoma] [Article in Italian] Palestini N, Tagliabue M, Cestino L, Farnetti A, Rossetto R, Vendrame A. Dipartimento di Discipline Medico-Chirurgiche, SCU Chirurgia Generale V, Universita degli Studi di Torino, Torino, Italy. Medullary thyroid carcinoma (MTC) is a rare thyroid malignancy, which is familial in 25-29% of cases. Familial MTC is due to germ-line mutations in the RET proto-oncogene. It can occur either alone or as the thyroid manifestation of MEN 2 syndromes; the disease is inherited in an autosomal dominant fashion with age-related penetrance. The treatment of choice is surgery. Early diagnosis and an adeguate initial operation provide the best chance of cure. Hence, the diagnosis should be made preoperatively. Genetic testing can identify almost all affected individuals with hereditary disease and permits prophylactic/early thyroidectomy in gene carriers. Total thyroidectomy and lymphadenectomy of the cervicocentral compartment is mandatory in all patients. In addition, bilateral dissection of the cervicolateral compartment should be done in all cases with more than microscopic disease. Plasma calcitonin is an excellent marker for postoperative follow-up. Treatment of persistent/recurrent disease is primarily surgical. Hence, a reoperative cervical lymphadenectomy should be considered in patients with persistently elevated calcitonin levels and no signs of distant metastases. Chemotherapy and external radiotherapy have little impact on the course of avanced disease; more promising is metabolic radiotherapy with Y90-DOTATOC in patients with somatostatin receptor-positive tumours. Publication Types: Review Review, Tutorial PMID: 14663408 [PubMed - indexed for MEDLINE] DR12: Expert Rev Mol Diagn. 2003 Nov;3(6):769-79. Molecular diagnosis of multiple endocrine neoplasia Type 2. Bugalho MJ, Domingues R, Sobrinho L. Servico de Endocrinologia e Laboratorio de Biologia Molecular, Instituto Portugues de Oncologia Francisco Genril, Centro Regional de Oncologia de Lisboa, SA, R. Prof. Lima Basto, 1099-023 Lisboa Codex, Portugal. mjbugalho@ipolisboa.min-saude.pt Multiple endocrine neoplasia Type 2 is a rare familial cancer syndrome transmitted in an autosomal dominant manner. It is characterized by the association of medullary thyroid carcinoma with pheochromocytoma and hyperparathyroidism. Medullary thyroid carcinoma, present in virtually all patients, is the principal cause of death. In 1993, germline mutations in the RET proto-oncogene were identified as the underlying cause of the syndrome. Genetic screening of at-risk family members can now be performed with high specificity and sensitivity. The ability to determine gene carrier status at a preclinical stage is of great value as it allows early prophylactic thyroidectomy. The specific RET codon mutation correlates with clinical variants of the syndrome, age at onset and aggressiveness of medullary thyroid carcinoma. This review will focus on mutational spectrum, genotype-phenotype correlations and clinical decisions based on genetic information. Publication Types: Review Review, Tutorial PMID: 14628904 [PubMed - indexed for MEDLINE] DR13: J Mol Med. 2003 Dec;81(12):819-23. Epub 2003 Nov 15. The newly detected mutations in the RET proto-oncogene in exon 16 as a cause of sporadic medullary thyroid carcinoma. Jindrichova S, Kodet R, Krskova L, Vlcek P, Bendlova B. Department of Molecular Endocrinology, Institute of Endocrinology, Narodni 8, 11694 Prague 1, Czech Republic. sarka@salon.cz Medullary thyroid carcinoma (MTC) occurs as a sporadic form or, less frequently, as an autosomal dominant inherited familial disorder. Germline mutations in the RET proto-oncogene in exons 10, 11, 13, 14, 15, and 16 are found in most of the familial cases (nearly 95%). Somatic mutations in sporadic MTC are detected in 23-69% of patients. The most frequent somatic mutation is located in exon 16 at codon 918, and only a small percentage of mutations are found in exons 10, 11, 13, and 15. We have searched for somatic mutations in Czech MTC patients using direct sequencing. We report here two new somatic missense mutations in exon 16 of the RET proto-oncogene associated with the sporadic MTC detected in two Czech men. A homozygous mutation at codon 922 TCC(Ser)-->CCC(Pro) as a result of loss of heterozygosity was revealed in the first patient. In the second one a heterozygous mutation at codon 930 ACG(Thr)-->ATG(Met) was found. PMID: 14618242 [PubMed - indexed for MEDLINE] DR14: Rev Med Interne. 2003 Nov;24(11):721-9. [Multiple endocrine neoplasias. Recent advances in clinical and genetic diagnosis] [Article in French] Bauters C, Leclerc L, Wemeau JL, Proye C, Pigny P, Porchet N. Clinique endocrinologique Marc-Linquette, CHRU de Lille, 6, rue du Professeur-Laguesse, 59037 Lille, France. c-cardot-bauters@chru-lille.fr PURPOSE: Multiple endocrine neoplasias (MEN) are autosomal dominant inherited syndromes characterized by the association of different glandular lesions in several members of the same kindred. The main clinical features of MEN 1 include primary hyperparathyroidism, pancreatic islet cell tumors and pituitary adenomas; less common features are adrenal adenomas, thymic and bronchial carcinoid tumors, lipomas and various cutaneous lesions. The MEN 2 syndromes (MEN 2A, MEN 2B and familial medullary thyroid carcinomas) are characterized by high penetrance of medullary thyroid carcinoma and differ in their variable expression of pheochromocytoma, hyperparathyroidism and other clinical features. CURRENT KNOWLEDGE AND KEY POINTS: MEN 1 tumor suppressor gene encodes a nuclear protein, menin, which interacts with different regulation transcription factors. The MEN 2 syndromes are caused by germ-line mutations of the RET proto-oncogene, which encodes a transmembrane tyrosine kinase. Genetic testing for mutations in these 2 genes allows identification of individuals predisposed to the disease, early diagnosis, and clinical and therapeutic management. FUTURE PROSPECTS AND PROJECTS: Fundamental approach will allow a best comprehension of physiopathogenic mechanisms of these disorders and the improvement of therapeutic management. Publication Types: Review PMID: 14604749 [PubMed - indexed for MEDLINE] DR15: J Clin Endocrinol Metab. 2003 Nov;88(11):5438-43. A novel germ-line point mutation in RET exon 8 (Gly(533)Cys) in a large kindred with familial medullary thyroid carcinoma. Da Silva AM, Maciel RM, Da Silva MR, Toledo SR, De Carvalho MB, Cerutti JM. Laboratory of Molecular Endocrinology, Division of Endocrinology, Department of Medicine, Escola Paulist de Medicina, Federal University of Sao Paulo, Brazil. Familial medullary thyroid carcinoma is related to germ-line mutations in the RET oncogene, mainly in cysteine codon 10 or 11, whereas noncysteine mutations in codons 13-15 are rare. We now report a new missense point mutation in exon 8 of the RET gene (1597G-->T) corresponding to a Gly(533)Cys substitution in the cysteine-rich domain of RET protein in 76 patients from a 6-generation Brazilian family with 229 subjects, with ascendants from Spain. It is likely that the mutation causes familial medullary thyroid carcinoma (FMTC), because no other mutation was found in RET, the mutation cosegregates with medullary thyroid carcinoma (MTC) or C cell hyperplasia (CCH) in patients subjected to surgery, and family members without the mutation are clinically unaffected. The histological analysis of 35 cases submitted to thyroidectomy revealed that 21 patients had MTC after the age of 40 yr and 8 before the age of 40 yr, 4 presented MTC or CCH before the age of 18 yr, 2 died due to MTC at the age of 53 and 60 yr, and CCH was found in a 5-yr-old child, suggesting a clinical heterogeneity. To improve the diagnosis of FMTC, analysis of exon 8 of RET should be considered in families with no identified classical RET mutations. PMID: 14602786 [PubMed - indexed for MEDLINE] DR16: Endocr Pathol. 2003 Fall;14(3):269-76. Concurrent lymph node metastases of medullary and papillary thyroid carcinoma in a case with RET oncogene germline mutation. Papi G, Corrado S, Pomponi MG, Carapezzi C, Cesinaro A, LiVolsi VA. Department of Internal Medicine, ASL Modena, University of Modena, Italy. papigiampaolo@hotmail.com We report the case of a 72 yr-old woman who underwent total thyroidectomy and resection of neck lymph nodes because of a firm nodule in the right lobe, which was consistent with medullary thyroid carcinoma (MTC) on cytological examination. Histology showed multifocal bilateral MTC; a 2 mm papillary thyroid carcinoma (PTC) was also detected in the right lobe, next to a focus of MTC; five cervical lymph nodes contained MTC. In one right perithyroidal lymph node, concurrent metastases of MTC and PTC were demonstrated. DNA analysis showed a point mutation in exon 14 at codon 804 of the RET proto-oncogene locus, as frequently found in cases of familial MTC (FMTC). To our knowledge, this case represents the first documented case of concurrent lymph node metastases of MTC and PTC in a patient with RET proto-oncogene germline mutation. We report this unique case, discuss related thyroid malignancies, and suggest possible underlying pathogenetic mechanisms. Publication Types: Case Reports PMID: 14586073 [PubMed - indexed for MEDLINE] NR17: Am J Clin Pathol. 2002 Dec;118 Suppl:S116-27. Molecular mutations in thyroid carcinogenesis. Hunt JL. Department of Pathology, University of Pittsburgh Medical Center, Pittsburgh, PA, USA. Molecular mutations in thyroid carcinomas have been well characterized and studied and consist of both germline and somatic genetic events. Mutations that are associated with tumorigenesis can be divided into 2 general categories: oncogene mutations and tumor suppressor gene mutations. Thyroid tumors and their characteristic molecular mutations are discussed in this review. The current practice in diagnostic testing for thyroid tumors also is examined. Publication Types: Review Review, Tutorial PMID: 14569818 [PubMed - indexed for MEDLINE] NR18: N Engl J Med. 2003 Oct 16;349(16):1566-8. Comment on: N Engl J Med. 2003 Oct 16;349(16):1517-25. Lessons learned from the management of a rare genetic cancer. Cote GJ, Gagel RF. Publication Types: Comment Editorial PMID: 14561800 [PubMed - indexed for MEDLINE] DR19: N Engl J Med. 2003 Oct 16;349(16):1517-25. Comment in: N Engl J Med. 2003 Oct 16;349(16):1566-8. N Engl J Med. 2004 Feb 26;350(9):943. Early malignant progression of hereditary medullary thyroid cancer. Machens A, Niccoli-Sire P, Hoegel J, Frank-Raue K, van Vroonhoven TJ, Roeher HD, Wahl RA, Lamesch P, Raue F, Conte-Devolx B, Dralle H; European Multiple Endocrine Neoplasia (EUROMEN) Study Group. Klinik fur Allgemein-, Viszeral-, und Gefasschirurgie, Martin-Luther-Universitat Halle-Wittenberg, Halle, Saale, Germany. gensurg@medzin.uni-halle.de BACKGROUND: An age-related progression from C-cell hyperplasia to medullary thyroid carcinoma is associated with various germ-line mutations in the rearranged during transfection (RET) proto-oncogene that could be used to identify the optimal time for prophylactic surgery. METHODS: In this European multicenter study conducted from July 1993 to February 2001, we enrolled patients who had a RET point mutation in the germ line, were 20 years of age or younger, were asymptomatic, and had undergone total thyroidectomy after confirmation of the RET mutation. Exclusion criteria were medullary thyroid carcinomas of more than 10 mm in greatest dimension and distant metastasis. RESULTS: Altogether, 207 patients from 145 families were identified. There was a significant age-related progression from C-cell hyperplasia to medullary thyroid carcinoma and, ultimately, nodal metastasis in patients whose RET mutations were grouped according to the extracellular- and intracellular-domain codons affected and in those with the codon 634 genotype. No lymph-node metastases were noted in patients younger than 14 years of age. The age-related penetrance was unaffected by the type of amino acid substitution encoded by the various codon 634 mutations. The codon-specific differences in the age at presentation of cancer and the familial rates of concomitant adrenal and parathyroid involvement suggest that the risk of progression was based on the transforming potential of the individual RET mutation. CONCLUSIONS: These data provide initial guidelines for the timing of prophylactic thyroidectomy in asymptomatic carriers of RET gene mutations. Copyright 2003 Massachusetts Medical Society Publication Types: Multicenter Study PMID: 14561794 [PubMed - indexed for MEDLINE] DR20: J Clin Endocrinol Metab. 2003 Oct;88(10):4932-7. Germline succinate dehydrogenase subunit D mutation segregating with familial non-RET C cell hyperplasia. Lima J, Teixeira-Gomes J, Soares P, Maximo V, Honavar M, Williams D, Sobrinho-Simoes M. Institute of Molecular Pathology and Immunology of the University of Porto, Porto 4200-465, Portugal. C cell hyperplasia is associated with medullary carcinoma of the thyroid in the inherited MEN2 syndromes, in which the great majority of cases have been shown to be due to a mutation in the RET oncogene. We report a study of a family with C cell hyperplasia and hypercalcitoninemia in which no cases of medullary carcinoma have yet occurred and which lacked an identifiable causative RET mutation. Four of the family members showed hypercalcitoninemia, and marked C cell hyperplasia was present in each of the three in whom thyroidectomy has been performed. We investigated the possible involvement of the SDHD gene, because somatic and germline mutations in this gene have been found in a variety of tumors of neural crest-derived tissue. A germline mutation in exon 2 of the SDHD gene (c149 A-G, His 50 Arg) was found in six members of the family; all the four available members with hypercalcitoninemia possessed the mutation. One of the five available members without hypercalcitoninemia, an 18-yr-old female, also showed the mutation. We conclude that we have identified a new syndrome, characterized by familial non-RET C cell hyperplasia. Our studies suggest that a mutation in SDHD may be causative. These observations have implications for apparently incidental cases of hypercalcitoninemia or C cell hyperplasia. PMID: 14557476 [PubMed - indexed for MEDLINE] DR21: J Clin Endocrinol Metab. 2003 Oct;88(10):4911-6. Intronic single nucleotide polymorphisms in the RET protooncogene are associated with a subset of apparently sporadic pheochromocytoma and may modulate age of onset. McWhinney SR, Boru G, Binkley PK, Peczkowska M, Januszewicz AA, Neumann HP, Eng C. Department of Molecular Genetics, The Ohio State University, Columbus, Ohio 43210, USA. Approximately 75% of pheochromocytomas are sporadic. Germline mutations in RET, VHL, SDHB, and SDHD have been shown to cause the 25% that are hereditary. Germline high penetrance gain-of-function RET mutations cause multiple endocrine neoplasia type 2, of which medullary thyroid carcinoma (MTC) and pheochromocytoma are components, whereas loss-of-function mutations cause Hirschprung disease (HSCR). A low-penetrance founder locus, in linkage disequilibrium with a RET ancestral haplotype comprising specific alleles at three intron (IVS) 1 single nucleotide polymorphisms (SNPs) (haplotype 0) and SNP A45A, predisposes to the majority of isolated HSCR. A different low-penetrance locus, in linkage disequilibrium with IVS 1 haplotype 2 and SNP S836S, was associated with a subset of sporadic MTC. We, therefore, sought to determine whether RET might also be a low-penetrance gene for apparently sporadic pheochromocytoma. We analyzed 104 pheochromocytoma cases without germline mutations in RET, VHL, SDHD, and SDHB for their status at A45, S836, three IVS 1 SNPs, and a novel upstream insertion/deletion variant. Pheochromocytoma cases were not associated with either A45A or S836S, but we found that cases were associated with haplotype 0 (P = 0.032). However, unlike HSCR, this pheochromocytoma-associated haplotype 0 was not associated with A45A. Taken together with the strengthening of association with the addition of the 5' insertion/deletion variant data (P = 0.016), our observations suggest the presence of a low-penetrance pheochromocytoma susceptibility locus in a region upstream of the putative loci for HSCR and apparently sporadic MTC. PMID: 14557473 [PubMed - indexed for MEDLINE] DR22: Surgery. 2003 Sep;134(3):425-31. Comment in: Surgery. 2004 Apr;135(4):447-8. Malignant progression from C-cell hyperplasia to medullary thyroid carcinoma in 167 carriers of RET germline mutations. Machens A, Holzhausen HJ, Thanh PN, Dralle H. Department of General, Visceral and Vascular Surgery, Martin-Luther-University, Halle-Wittenberg, Halle/Saale, Germany. BACKGROUND: Hereditary medullary thyroid carcinoma (MTC) is the most common and potentially life-shortening phenotypic manifestation of RET (rearranged during transfection) germline mutations. If a distinct time lag between the successive stages of malignant progression were identifiable, the information could be used to individualize prophylactic surgery. The study objective was to investigate the impact of RET genotype on disease progression from C-cell hyperplasia (CCH) to MTC. METHODS: An institutional series of 167 (67 index, 100 nonindex) consecutive carriers of RET gene point mutations in exons 10, 11, 13, 14, or 16 who underwent total thyroidectomy between November 1994 and November 2002. RESULTS: Regarding codons 618, 620, 634, 768, 790, and 804, patient age at diagnosis differed significantly depending on the type of pathology encountered (CCH, MTC without and with nodal metastasis). The variability in age, which may reflect the number of necessary somatic mutations, explained the pathological strata in 38% (codon 634) to 77% (codon 768) of patients. Conversely, 62% (codon 634) to 23% (codon 768) of variability in age at different pathological strata may have been determined by the RET genotype. CONCLUSIONS: The pace of malignant progression of the RET genotype should be taken into account when considering prophylactic thyroidectomy in RET gene carriers. PMID: 14555929 [PubMed - indexed for MEDLINE] DR23: J Biol Chem. 2003 Dec 26;278(52):52131-8. Epub 2003 Oct 10. Microsomal prostaglandin E2 synthase-1 is induced by conditional expression of RET/PTC in thyroid PCCL3 cells through the activation of the MEK-ERK pathway. Puxeddu E, Mitsutake N, Knauf JA, Moretti S, Kim HW, Seta KA, Brockman D, Myatt L, Millhorn DE, Fagin JA. Division of Endocrinology and Metabolism, University of Cincinnati College of Medicine, Cincinnati, Ohio 45267, USA. RET/PTC rearrangements are believed to be tumor-initiating events in papillary thyroid carcinomas. We identified microsomal prostaglandin E2 synthase-1 (mPGES-1) as a RET/PTC-inducible gene through subtraction hybridization cloning and expression profiling with custom microarrays. The inducible prostaglandin E2 (PGE2) biosynthetic enzymes cyclooxygenase-2 (COX-2) and mPGES-1 are up-regulated in many cancers. COX-2 is overexpressed in thyroid malignancies compared with benign nodules and normal thyroid tissues. Eicosanoids may promote tumorigenesis through effects on tumor cell growth, immune surveillance, and angiogenesis. Conditional RET/PTC1 or RET/PTC3 expression in PCCL3 thyroid cells markedly induced mPGES-1 and COX-2. PGE2 was the principal prostanoid and up-regulated (by approximately 60-fold), whereas hydroxyeicosatetraenoic acid metabolites were decreased, consistent with shunting of prostanoid biosynthesis toward PGE2 by coactivation of the two enzymes. RET/PTC activated mPGES-1 gene transcription. Based on experiments with kinase inhibitors, with PCCL3 cell lines with doxycycline-inducible expression of RET/PTC mutants with substitutions of critical tyrosine residues in the kinase domain, and lines with inducible expression of activated mutants of H-RAS and MEK1, RET/PTC was found to regulate mPGES-1 through Shc-RAS-MEK-ERK. These data show a direct relationship between activation of a tyrosine kinase receptor oncogene and regulation of PGE2 biosynthesis. As enzymes involved in prostanoid biosynthesis can be targeted with pharmacological inhibitors, these findings may have therapeutic implications. PMID: 14555660 [PubMed - indexed for MEDLINE] NR24: Mol Biotechnol. 2003 Oct;25(2):113-29. Detection of mutations in RET proto-oncogene codon 634 through double tandem hybridization. Maldonado-Rodriguez R, Espinosa-Lara M, Barrera-Leon O, Colin-Tovar C, Gonzalez-Yebra B, Salcedo-Vargas M, Santiago-Hernandez JC, Mendez-Tenorio A, Beattie KL. Escuela Nacional de Ciencias Biologicas, IPN, Mexico, 11340, DF, Mexico. We developed a procedure to detect the 7 point mutations at Cys634 of the proto-oncogene RET, which is responsible for medullary thyroid carcinoma (MTC). Genomic DNA was prepared from blood samples obtained from normal and MTC-affected individuals belonging to a family with a history of the disease. The RET genotype for each individual was first established by performing restriction and sequencing analyses. Single-stranded target DNA was prepared by asymmetric polymerase chain reaction (PCR) amplification of a 93-bp fragment containing Cys634. The target was annealed with pairs of prelabeled stacking oligonucleotides designed to create appropriate 7-nucleotide gaps, which served as the sites of subsequent hybridization with glass-immobilized 7-mer probes. The target-stacking oligonucleotide duplexes were hybridized with DNA chips containing a set of eight 7-mer probes designed to detect the wild-type sequence and the seven point mutations described. We tested two sets of immobilized probes containing internal or 5'-terminal codon-634 single-base variations. Both groups of probes were able to discriminatively identify the mutations. The hybridization patterns indicated that the disease in this family was due to the C634Y mutation, in accord with the original sequence analysis. The hybridization-based mutation assignment was additionally supported by determination of the control homozygous and heterozygous hybridization patterns produced with synthetic targets having the normal or codon 634 mutant sequences. The effects of mismatch type and nearest-neighbor sequences on the occurrence of false-positive (mismatched) hybridizations are discussed. PMID: 14526122 [PubMed - indexed for MEDLINE] NR25: Langenbecks Arch Chir Suppl Kongressbd. 1998;115(Suppl I):261-5. [Association of deletions of the RET proto-oncogene wtih aggressive course of sporatic C-cell carcinoma] [Article in German] Musholt PB, Musholt TJ, Moley JF, Scheumann GF. Klinik fur Abdominal- u. Transplantationschirurgie, Medizinische Hochschule Hannover. A growing number of reports describing the association of certain deletions within exon 11 of the RET proto-oncogene with aggressive courses of medullary thyroid carcinoma, point to a potential prognostic relevance of molecular features in the sporadic tumor, analogous to the hereditary variant. PMID: 14518256 [PubMed - indexed for MEDLINE] DR26: Dtsch Med Wochenschr. 2003 Sep 26;128(39):1998-2002. [Hereditary medullary thyroid carcinoma--genotype-phenotype characterization] [Article in German] Frank-Raue K, Heimbach C, Rondot S, Usadel KH, Meng W, Varma C, Fuchs-Hammoser R, Hoppner W, Schulze E, Raue F. Endokrinologische Gemeinschaftspraxis, Heidelberg. raue-heidelberg@t-online.de BACKGROUND AND OBJECTIVE: Hereditary medullary thyroid carcinoma (MTC) is caused by germline mutations of the RET proto-oncogene. A genotype - phenotype correlation has been established, showing clustering of mutations in exons 10 and 11 in classical MEN 2 A syndrome, in exon 16 codon 918 in MEN 2 B syndrome and in exons 13-15 in familial MTC. A line of evidence suggested that the development and the aggressiveness of MTC in the different cancer syndromes is variable. Aim of this study was to compare the phenotype of exon 13-15 mutations with that of exon 11 mutation and possibly draw therapeutical consequences. PATIENTS AND METHODS: We compared the phenotype of 47 patients with mutations in exon 13-15 with 66 patients with exon 11, codon 634 mutation, the classical MEN2A. Patients were further subdivided as index and screening patients. RESULTS: Mean age of 19 index patients with codon 790, 791, 804 or 891 mutation was significant higher compared with 18 index patients with codon 634 mutation (mean age at diagnosis 50+/-12 years; range 30-69 y vs mean age 31+/-9 years; range 17-49 y), tumor stage at operation was favourable (C-cell hyperplasia n = 1; stage I n = 8; II n = 3; III n = 2; IV n = 2; no operation n = 1; no information n = 2 vs stage I n = 3; stage II n = 6; stage III n = 4, no information n =5), cure rate was better (56 % vs 38 %) and the death rate was lower (n = 2 vs n = 4). In screening patients no differences concerning the age, tumor stage, cure and death rate between patients with exons 13-15 and codon 634 mutations were seen. CONCLUSIONS: MTC in patients with exon 790, 791, 804, 891 mutations displayed a late onset and an indolent course compared to codon 634 mutation, this has to be taken into account when recommending timing and extent of prophylactic surgery. PMID: 14508694 [PubMed - indexed for MEDLINE] DR27: Cancer Res. 2003 Sep 1;63(17):5559-63. CEP-701 and CEP-751 inhibit constitutively activated RET tyrosine kinase activity and block medullary thyroid carcinoma cell growth. Strock CJ, Park JI, Rosen M, Dionne C, Ruggeri B, Jones-Bolin S, Denmeade SR, Ball DW, Nelkin BD. The Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, Maryland 21231, USA. All of the cases of medullary thyroid carcinoma (MTC) express the RET receptor tyrosine kinase. In essentially all of the hereditary cases and approximately 40% of the sporadic cases of MTC, the RET kinase is constitutively activated by mutation. This suggests that RET may be an effective therapeutic target for treatment of MTC. We show that the indolocarbazole derivatives, CEP-701 and CEP-751, inhibit RET in MTC cells. These compounds effectively inhibit RET phosphorylation in a dose-dependent manner at concentrations <100 nM in 0.5% serum and at somewhat higher concentrations in the presence of 16% serum. They also blocked the growth of these MTC cells in culture. CEP-751 and its prodrug, CEP-2563, also inhibited tumor growth in MTC cell xenografts. These results show that inhibiting RET can block the growth of MTC cells and may have a therapeutic benefit in MTC. PMID: 14500395 [PubMed - indexed for MEDLINE] NR28: Med Clin (Barc). 2003 Sep 6;121(7):264-9. [Thyroid carcinomas of the follicular epithelium: tumor markers and oncogenes] [Article in Spanish] Alvarez-Nunez F, Mora J, Matias-Guiu X; Marcadores Tumorales de Neoplasias tiroideas del Hospital de Sant Pau. Hospital de la Santa Creu i Sant Pau. Universitat Autonoma. Barcelona. Espana. Several genes control cell growth, differentiation and apoptosis. Any alteration in the sequence or expression of these genes can cause an uncontrolled growth of the tissue and produce a tumor. Quantitative and qualitative gene expression studies using genes as tumor markers are essential for the diagnosis and prognosis of the tumor and its behavior. Oncogenes are genes that stimulate cell growth and have an increased expression. On the contrary, tumor suppressor genes are genes that inhibit cell growth and have a decreased expression in tumor cells. To study these tumor markers we apply simple and random molecular biology techniques such as polymerase chain reaction (PCR), reverse transcription and genomic sequencing. In the case of thyroid epithelial neoplasia, tumor markers such as PTEN/MMAC1/TEP1, telomerase, RET/PTC, b-catenine, PAX8/PPAR(1, ciclooxygenase, thyroid stimulating hormonal receptor (TSHR), and thyro-globulin are being investigated. These markers are analyzed for somatic mutations in the genetic sequence, chromosomical rearrangements, alterations in the promoter zone that affect gene expression, regulation and studies of genes at mRNA level. A deeper study of these markers is deemed to help improve the accuracy of tumor diagnosis, behavior and prognosis. Hence, more effective therapeutic options will be adapted to each individual, eventually reducing hospital costs. Publication Types: Review Review, Tutorial PMID: 12975039 [PubMed - indexed for MEDLINE] DR29: Am J Clin Pathol. 2003 Jun;119 Suppl:S17-38. Standard and molecular cytogenetics of endocrine tumors. Herrmann M. Department of Gynecologic and Breast Pathology, Armed Forces Institute of Pathology, Washington, DC, USA. mherrm@earthlink.net Standard cytogenetic data are reported for benign and malignant thyroid and pituitary tumors. These identified chromosomal rearrangements activating RET and PPAR gamma 1 in a subset of papillary (PTCs) and follicular thyroid carcinomas (FTCs) and amplification of PKC epsilon in FTCs. Increases in complex karyotypes accompany progression in thyroid lesions. For pituitary tumors, karyotypic abnormalities more often affect functioning than nonfunctioning tumors. Such differences extend into comparative genomic hybridization (CGH), with a similar distribution for chromosomal imbalances. CGH data are reported on all varieties of endocrine tumors, supporting some cytogenetic findings and adding new hotspots for genomic imbalances. Increases in genomic imbalance accompany clinical progression in malignant thyroid tumors, adult adrenocortical tumors, parathyroid tumors, and some pancreatic endocrine tumors (PETs), e.g., insulinomas. Pheochromocytoma and FTC show more losses than gains. Specific patterns of imbalances are emerging for gastrointestinal PETs regarding location and hormone status; for pheochromocytomas, medullary thyroid carcinomas, and parathyroid tumors regarding genetic syndrome association; and for pituitary tumors regarding hormone status. Publication Types: Review PMID: 12951842 [PubMed - indexed for MEDLINE] DR30: Surg Oncol. 2003 Aug;12(2):101-4. Management of hereditary thyroid cancer in children. Skinner MA. Duke University Medical Center, Durham, NC 27710, USA. skinn009@mc.duke.edu Hereditary thyroid cancer in childhood occurs in the setting of Multiple Endocrine Neoplasia types 2A and 2B, and familial medullary thyroid carcinoma, FMTC. Prophylactic thyroidectomy in childhood has been recommended in patients found to have inherited mutations in the RET protooncogene, to prevent the development of medullary thyroid carcinoma. In this report are presented the clinical and genetic aspects of hereditary thyroid cancer in children, as well as surgical recommendations and medium-term outcome results. Publication Types: Review Review, Tutorial PMID: 12946481 [PubMed - indexed for MEDLINE] DR31: Curr Treat Options Oncol. 2003 Aug;4(4):339-47. Medullary thyroid carcinoma. Moley JF. Endocrine and Oncologic Surgery, Siteman Cancer Center, Washington University School of Medicine, Box 8109, 660 South Euclid, St. Louis, MO 63110, USA. moleyj@msnotes.wustl.edu Medullary thyroid carcinoma (MTC) is a neuroendocrine malignancy that occurs in hereditary (25%) and sporadic (75%) clinical settings. MTC is present in all patients with the multiple endocrine neoplasia type 2 syndromes. MTCs produce calcitonin, the measurement of which can indicate the presence of tumors in people who are at risk and the effectiveness of therapy in treated patients. Surgical cure is possible in young patients with multiple endocrine neoplasia type 2 who undergo preventative thyroidectomy (approximately 50% of patients who are diagnosed with a palpable thyroid mass) and in some patients with recurrent nodal metastatic disease in the neck. Mortality from MTC is caused by tumor invasion of the trachea, great vessels in the neck, or mediastinum or by the effects of distant metastatic disease. Surgery for cervical recurrence can prevent death from tracheal invasion. The role of radiation therapy is not well defined. There is no effective systemic therapy for MTC. Activating mutations in a tyrosine kinase receptor gene (RET) are present in most MTCs, and experience with tyrosine kinase inhibitors and other agents in clinical trials is critical for the identification of effective systemic treatment. PMID: 12943614 [PubMed - indexed for MEDLINE] DR32: Rev Med Liege. 2003 May;58(5):346-50. [Medullary thyroid cancer: how tumor markers and genetics determine preventive measures] [Article in French] Meurisse N, Defechereux T, Hamoir E, Maweja S, Meurisse M, Beckers A. Service de Chirurgie Abdominale, Endocrine et de Transplantation, CHU Sart Tilman, Liege. Medullary thyroid cancer (MTC) arises from parafollicular C cells secreting calcitonin. MTC occurs both as sporadic tumors and as part of specific inherited autosomal dominant syndromes in which point mutations within a discrete set of RET codons were described. Total thyroidectomy and aggressive neck dissection represents the only chance for cure in the affected patients. Therefore, all patients with thyroid nodular disease should undergo measurement of calcitonin plasma levels to allow preclinical diagnosis of the disease and early appropriate surgery ("secondary prevention"). In case of proband patient for inherited disease, all the family members should be genetically screened to detect the disease gene carriers. Patients with germline mutation would benefit either from earlier surgery at the stage of C-cell hyperplasia or microcarcinoma or prophylactic surgery (total thyroidectomy without neck dissection) (primary prevention) before the onset of any C-cells pathology. The ideal age for performance of such prophylactic surgery is determined by the genotypic features of the disease. Publication Types: Review Review, Tutorial PMID: 12940128 [PubMed - indexed for MEDLINE] DR33: J Med Assoc Thai. 2003 Jun;86 Suppl 2:S472-6. A RET C634R mutation in a Thai female with multiple endocrine neoplasia type 2A. Sunthornyothin S, Sinthuwiwat T, Shotelersuk V. Department of Internal Medicine, Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand. Multiple endocrine neoplasia type 2A (MEN 2A) is an autosomal dominant disorder characterized by medullary thyroid carcinoma, pheochromocytoma and primary hyperparathyroidism. The first tumor is usually a medullary thyroid carcinoma. MEN 2A is caused by mutations in the RET proto-oncogene. The detection of mutations in the gene has important diagnostic and therapeutic impacts. Genetic testing of at-risk family members allows one to identify individuals carrying the mutant alleles with very high specificity and sensitivity. Subsequently, total thyroidectomy, recommended at 5 years of age, can be performed in a prophylactic attempt. The authors performed a molecular analysis to identify a mutation in a Thai woman with MEN 2A. She was found to be heterozygous for 1900T>C (C634R). The patient had two daughters who were not found to carry the mutation. The newly available genetic test for patients with MEN 2A in Thailand makes possible accurate DNA-based diagnosis of their at-risk family members before development of the disease, which has important therapeutic impacts for them. Publication Types: Case Reports PMID: 12930027 [PubMed - indexed for MEDLINE] PR34: Mod Pathol. 2003 Aug;16(8):756-63. C-cell hyperplasia and medullary thyroid carcinoma: clinicopathological and genetic correlations in 66 consecutive patients. Guyetant S, Josselin N, Savagner F, Rohmer V, Michalak S, Saint-Andre JP. Department of Pathology, Centre Hospitalier Universitaire, Angers, France. guyetant@med.univ-tours.fr Routine calcitonin (CT) assay programs and genetic testing for RET proto-oncogene mutations have consistently modified the management and understanding of C-cell proliferative disorders. We report a series of 66 consecutive patients with C-cell hyperplasia (CCH) or medullary thyroid carcinoma (MTC) observed in our institution within an 8-year time period. All the patients had a preoperative basal CT assay and an RET proto-oncogene sequencing. Seventeen patients (F-M ratio: 8:9, mean age: 29.7 y) had a multiple endocrine neoplasia Type 2: 3 children <10 years of age had CCH only, and 14 patients had an MTC, with neoplastic CCH in 10/14 cases. Twenty-seven patients (F-M ratio: 18:9, mean age: 56.6 y) had a sporadic MTC, with physiological CCH in 8 and neoplastic CCH in 3 cases. Twenty-two men (mean age: 46.2 y) had CCH only (physiological CCH in 17 men and neoplastic CCH in 5). We conclude that (1) clinical and pathological characteristics (familial MTC, tumor multifocality, neoplastic CCH) usually associated with hereditary MTC may be misleading and that on the contrary, RET sequencing gives no false positive result; (2) sporadic neoplastic CCH accompanies (and probably precedes) a number of sporadic MTC; and (3) women presenting with a sporadic elevated basal CT have a 100% risk of having an MTC (15/15), but this risk is 3-fold less in men (31%), who will most often have CCH only (69%). PMID: 12920219 [PubMed - indexed for MEDLINE] PR35: Cancer Res. 2003 Aug 1;63(15):4561-7. High prevalence of BRAF gene mutation in papillary thyroid carcinomas and thyroid tumor cell lines. Xu X, Quiros RM, Gattuso P, Ain KB, Prinz RA. Department of General Surgery, Rush Presbyterian St. Luke's Medical Center, 1653 West Congress Parkway, Chicago, IL 60612, USA. xxu@rush.edu The RAS-RAF-MEK-ERK-MAP kinase pathway mediates the cellular response to extracellular signals that regulate cell proliferation, differentiation, and apoptosis. Mutation of the RAS proto-oncogene occurs in various thyroid neoplasms such as papillary thyroid carcinomas (PTCs), follicular thyroid adenomas and carcinomas. A second genetic alteration frequently involved in PTC is RET/PTC rearrangements. Recent studies have shown that BRAF, which is a downstream signaling molecule of RET and RAS, is frequently mutated in melanomas. This study tests whether BRAF is also mutated in thyroid tumors and cell lines. We analyzed BRAF gene mutation at codon 599 in thyroid tumors using mutant-allele-specific PCR and in 10 thyroid tumor cell lines by DNA sequencing of the PCR-amplified exon 15. We found that BRAF was mutated in 8 of 10 thyroid tumor cell lines, including 2 of 2 papillary carcinoma cell lines, 4 of 5 anaplastic carcinoma cell lines, 1 of 2 follicular carcinoma cell lines, and 1 follicular adenoma cell line. BRAF mutation at codon 599 was detected in 21 of 56 PTC (38%) but not in 18 follicular adenomas and 6 goiters. BRAF mutation occurred in PTC at a significantly higher frequency in male patients than in female patients. To test whether BRAF mutation may cooperate with RET/PTC rearrangements in the oncogenesis of PTC, we tested whether BRAF-mutated PTCs were also positive for RET/PTC rearrangements. Immunohistochemical staining was conducted to evaluate RET/PTC rearrangements by using two different anti-RET antibodies. Surprisingly, we found that a large number of BRAF-mutated PTCs (8 of 21) also expressed RET, indicating that the RET proto-oncogene is rearranged in these BRAF-mutated PTCs. These observations suggest that mutated BRAF gene may cooperate with RET/PTC to induce the oncogenesis of PTC. PMID: 12907632 [PubMed - indexed for MEDLINE] DR36: Genetika. 2003 Jun;39(6):847-54. [Analysis of mutations in the RET proto-oncogene in patients with medullary thyroid tumor] [Article in Russian] Amosenko FA, Brzhezovskii VZh, Liubchenko LN, Shabanov MA, Kozlova VM, Vanushko VE, Kazubskaia TP, Gar'kavtseva RF, Kalinin VN. Research Center for Medical Genetics, Russian Academy of Medical Sciences, Moscow, 115478 Russia. amossenko@medgen.ru The spectrum of mutations of the RET protooncogene was analyzed in Russian patients with inherited or sporadic medullary thyroid carcinoma (MTC). Four RET exons (11, 13, 15, and 16) were subjected to molecular analysis, and mutations were revealed and identified in 47.4% (9/19) patients with sporadic MTC. In total, six mutations (including three new ones) were observed. The most common mutation affected codon 918 to cause substitution of methionine with threonine and accounted for 31.6% alleles. Analysis of exons 11 and 16 revealed four mutations in patients with inherited multiple endocrine neoplasia type 2 (MEN 2). Mutations were found in each patient. Thyroidectomy was performed in four asymptomatic carriers of RET mutations from three MET 2A families (in two families, affected relatives had bilateral pheochromocytoma). In two patients, analysis of the surgery material revealed MTC microfoci in both lobes of the thyroid gland. The results provide the ground for constructing a bank of genetic information on Russian MTC patients with the clinically verified diagnosis. PMID: 12884527 [PubMed - indexed for MEDLINE] DR37: Oncogene. 2003 Jul 17;22(29):4578-80. BRAF mutations and RET/PTC rearrangements are alternative events in the etiopathogenesis of PTC. Soares P, Trovisco V, Rocha AS, Lima J, Castro P, Preto A, Maximo V, Botelho T, Seruca R, Sobrinho-Simoes M. Institute of Molecular Pathology and Immunology of the University of Porto, (IPATIMUP), Rua Roberto Frias s/n, 4200-465 Porto, Portugal. Rearrangement of RET proto-oncogene is the major event in the etiopathogenesis of papillary thyroid carcinoma (PTC). We report a high prevalence of BRAF(V599E) mutation in sporadic PTC and in PTC-derived cell lines. The BRAF(V599E) mutation was detected in 23 of 50 PTC (46%) and in three of four PTC-derived cell lines. The prevalence of the BRAF(V599E) mutation in PTC is the highest reported to date in human carcinomas, being only exceeded by melanoma. PTC with RET/PTC rearrangement as well as the TPC-1 cell line (the only one harboring RET/PTC rearrangement) did not show the BRAF(V599E) mutation. BRAF(V599E) mutation was not detected in any of 23 nodular goiters, 51 follicular adenomas and 18 follicular carcinomas. A distinct mutation in BRAF (codon K600E) was detected in a follicular adenoma. Activating mutations in RAS genes were detected in 15% of FA, 33% of FTC and 7% of PTC. BRAF(V599E) mutation did not coexist with alterations in any of the RAS genes in any of the tumors. These results suggest that BRAF(V599E) mutation is frequent in the etiopathogenesis of PTC. The BRAF(V599E) mutation appears to be an alternative event to RET/PTC rearrangement rather than to RAS mutations, which are rare in PTC. BRAF(V599E) may represent an alternative pathway to oncogenic MAPK activation in PTCs without RET/PTC activation. PMID: 12881714 [PubMed - indexed for MEDLINE] NR38: Oncogene. 2003 Jul 17;22(29):4569-77. Tyrosine kinase oncoprotein, RET/PTC3, induces the secretion of myeloid growth and chemotactic factors. Russell JP, Shinohara S, Melillo RM, Castellone MD, Santoro M, Rothstein JL. Department of Microbiology/Immunology, Kimmel Cancer Institute, Thomas Jefferson University, Philadelphia, PA 19107, USA. Differentiated thyroid carcinomas are the most frequent endocrine neoplasms, but account for few cancer-related deaths. Although the indolent growth of these cancers correlates well with longevity, the biological basis for this good prognosis is not known. In contrast, two of the most frequent autoimmune diseases involve the thyroid suggesting a high propensity for this organ to invoke destructive immunity. Unfortunately, the mechanism linking malignancy and autoimmunity is not clear, although the expression of the oncogenic fusion protein RET/PTC3 (RP3) in both of these disorders may provide a clue. Interestingly, the signaling caused by activated RET kinase involves overlapping pathways and some common to the inflammatory response. Accordingly, we analyzed the function of RP3 and a mutant RP3 molecule to induce proinflammatory pathways in thyroid epithelial cells. Indeed, we find that RP3 alone causes increases in nuclear NF-kappaB activity and secretion of MCP-1 and GM-CSF. Finally, transfer of RP3-expressing thyrocytes into mice in vivo attracted dense macrophage infiltrates, which lead to rapid thyroid cell death. Further, cytokine synthesis and inflammation was largely abrogated by mutation of RP3 Tyr588; an important protein-binding site for downstream signaling. Together, these studies implicate oncogene-induced cytokine-signaling pathways in a new mechanism linking inflammation with cancer. PMID: 12881713 [PubMed - indexed for MEDLINE] PR39: Arkh Patol. 2003 May-Jun;65(3):7-9. [A familial form of medullary carcinoma of the thyroid gland] [Article in Russian] Rotin DL, Brzhezovskii VZh, Pavlovskaia AI, Smirnova EA, Anurova OA. N. N. Blokhin Cancer Research Center, 115478, Moscow. A case of a family form of medullary thyroid cancer is reported. Histological, immunohistochemical and ultrastructural data are presented and problems of etiology, pathogenesis and diagnosis are discussed. Publication Types: Case Reports PMID: 12879602 [PubMed - indexed for MEDLINE] DR40: Hum Mutat. 2003 Aug;22(2):177. Novel intronic polymorphisms in the RET proto-oncogene and their association with Hirschsprung disease. Fitze G, Schierz M, Kuhlisch E, Schreiber M, Ziegler A, Roesner D, Schackert HK. Department of Pediatric Surgery, University of Technology Dresden, Germany. guido.Fitz@mailbox.tu-dresden.de Germline mutations of the RET proto-oncogene have been found in familial and sporadic forms of Hirschsprung disease (HSCR), but also in the autosomal dominantly inherited multiple endocrine neoplasia type 2 (MEN2) syndromes, which comprise the medullary thyroid carcinoma (MTC) as an obligatory feature. Besides mutations various polymorphisms of the RET proto-oncogene are associated with the HSCR. In this study, we have characterized seven intronic RET polymorphisms (IVS2+9G>A, IVS4+48A>G, IVS12+47C>T, IVS14-24G>A, IVS19+47T>C, IVS20+96C>T, 3'UTR+124A>G) and investigated these variants by DNA sequencing in populations of 76 HSCR patients and 40 sporadic MTC patients as well as in a control population. Variants of four of these seven polymorphisms have a strong association with the HSCR phenotype. In contrast, none of the investigated polymorphisms show a significant difference in the genotype distribution and the allele frequencies in patients with sporadic MTC when compared to controls. These findings support the hypothesis that specific RET haplotypes cause or modify the HSCR phenotype. Copyright 2003 Wiley-Liss, Inc. PMID: 12872262 [PubMed - indexed for MEDLINE] PR41: Lab Anim. 2003 Jul;37(3):215-21. The Ret proto-oncogene in the WAG/Rij rat strain: an animal model for inherited C-cell carcinoma? De Miguel M, Fernandez-Santos JM, Trigo-Sanchez I, Matera I, Ceccherini I, Martin I, Romeo G, Galera-Davidson H. Departamento Citologia e Histologia Normal y Patologica, Facultad de Medicina, University of Seville, 41009 Sevilla, Spain. WAG/Rij rat strain has been suggested as an animal model for the study of inherited human medullary thyroid carcinoma (MTC), due to its high incidence of spontaneous C-cell thyroid tumours. Although the role of the Ret proto-oncogene mutations, as responsible for human MTC, is well established, nothing has been published concerning this putative animal model. Based upon the previously reported rat Ret sequence, exons 10, 11, 13, 14, 15, and 16, known to carry activating mutations in humans, have been analysed in the WAG/Rij rat by PCR, single strand conformational polymorphism (SSCP) and direct sequencing. Neither the germline nor MTC samples showed any Ret sequence difference in the exons when analysed in comparison to a non-MTC-susceptible rat strain. Our results indicate that Ret exons relevant in humans are not involved in WAG/Rij rat MTC, as expected, and this questions the validity of this strain as a model for the human disease, and suggests there must be additional mechanisms for the genesis and progression of rat MTC. PMID: 12869284 [PubMed - indexed for MEDLINE] DR42: Hum Gene Ther. 2003 Jul 1;14(10):971-82. Antitumor capacity of a dominant-negative RET proto-oncogene mutant in a medullary thyroid carcinoma model. Drosten M, Stiewe T, Putzer BM. Center for Cancer Research and Cancer Therapy, Institute of Molecular Biology, University of Essen Medical School, 45122 Essen, Germany. Gain-of-function mutations in the RET proto-oncogene resulting in a constitutively active receptor tyrosine kinase have been identified as responsible for three subtypes of multiple endocrine neoplasia type 2 (MEN-2) and the development of sporadic medullary and papillary thyroid carcinoma. An important strategy in cancer gene therapy is the inhibition of oncogenic signal transduction by interfering with the molecular mechanisms of activation. In the present study, we tested the therapeutic capacity of an adenovirus expressing a dominant-negative (dn) RET mutant, RET(51).flag, under the control of a synthetic C cell-selective calcitonin promoter (TSE2.CP1) against human medullary thyroid cancer (MTC). Infection of human MTC-derived TT cells with Ad-TSE2.CP1-dn-RET(51).flag resulted in the accumulation of immature RET protein in the endoplasmic reticulum and a strong reduction of oncogenic RET receptor on the cell surface, indicating that RET(51).flag exhibits a dominant-negative effect over endogenous oncogenic protein. Analysis of potential downstream mechanisms associated with the inhibition of oncogenic RET signaling by overexpression of mutant RET(51).flag revealed a significant loss of cell viability in TT cells due to the induction of apoptosis. Finally, we examined the antitumor activity of the dominant-negative RET approach in vivo. Inoculation of Ad-TSE2.CP1- dn-RET(51).flag-expressing MTC cells into nude mice led to complete suppression of tumor growth. Moreover, a single intratumoral injection of Ad-TSE2.CP1-dn-RET(51).flag into established thyroid tumors resulted in prolonged survival of treated mice compared with the controls. Our data suggest that adenoviral delivery of dn-RET(51).flag may be a reliable strategy of effective molecular intervention for RET oncogene-related MTC. PMID: 12869215 [PubMed - indexed for MEDLINE] PR43: Am J Clin Pathol. 2003 Jul;120(1):71-7. Comment in: Am J Clin Pathol. 2003 Nov;120(5):803; author reply 804. Molecular profile and clinical-pathologic features of the follicular variant of papillary thyroid carcinoma. An unusually high prevalence of ras mutations. Zhu Z, Gandhi M, Nikiforova MN, Fischer AH, Nikiforov YE. Departments of Pathology and Laboratory Medicine, University of Cincinnati, Cincinnati, 231 Albert Sabin Way, PO Box 670529, Cincinnati, OH 45267-0529, USA. The follicular variant (FV) of papillary thyroid carcinoma is characterized by a follicular growth pattern and cytologic features of papillary carcinoma. ret/PTC rearrangements are common in classic papillary thyroid carcinoma (PTC) and PAX8-PPAR gamma and ras mutations in follicular thyroid carcinoma. Their prevalence in FV has not been established. We studied these genetic alterations and clinical-pathologic features in 30 FV cases and compared those with 46 non-FV papillary carcinomas. FV cases revealed 1 ret/PTC rearrangement (3%) and 13 ras mutations (43%). Non-FV cases harbored 13 ret/PTC (28%) (P = .006) and no ras mutations (P = .0002). No PAX8-PPAR gamma was found in either group. FV cases demonstrated a significantly higher prevalence of tumor encapsulation, angiovascular invasion, and poorly differentiated areas and a lower rate of lymph node metastases. These data indicate that the FV of papillary carcinoma has a distinct set of molecular alterations and is characterized by a high frequency of ras point mutations. PMID: 12866375 [PubMed - indexed for MEDLINE] DR44: Clin Endocrinol (Oxf). 2003 Aug;59(2):156-61. Frequent association between MEN 2A and cutaneous lichen amyloidosis. Verga U, Fugazzola L, Cambiaghi S, Pritelli C, Alessi E, Cortelazzi D, Gangi E, Beck-Peccoz P. University of Milan, Ospedale Maggiore IRCCS, Italy. OBJECTIVE: Multiple endocrine neoplasia type 2A (MEN 2A) and familial medullary thyroid carcinoma (FMTC) are genetic diseases due to activating mutations of the RET proto-oncogene. Affected patients develop medullary thyroid carcinoma (100%), in an isolated form (FMTC) or in association with phaeochromocytoma (30-50%), and primary hyperparathyroidism (10-20%) (MEN 2A). The presence of cutaneous lichen amyloidosis (CLA) has been anecdotally described in few families harbouring RET proto-oncogene mutation in codon 634. The aim of the study was to evaluate the incidence of CLA in MEN 2A/FMTC families. PATIENTS AND DESIGN: Ten MEN 2A/FMTC families were studied and RET gene mutations identified in all. Complete dermatological assessment was carried out in each family member. Skin biopsy for histological studies was performed in patients with CLA. RESULTS: Among 10 MEN 2A/FMTC families, the presence of CLA was found only in patients belonging to the three families with MEN 2A and RET mutation in codon 634. Nine of 25 patients (36%) with codon 634 mutation presented CLA, though two of them did not show CLA skin lesions but the typical neurological pruritus in the upper back. In all patients, neurological pruritus was present since infancy as a precocious marker of the disorder. The dermatological study of patients with CLA skin lesions added further evidence that pruritus has a pivotal role in the development of CLA, the amyloid deposition being the consequence of repeated scratching. Light microscopy revealed orthokeratotic hyperkeratosis, with elongation of the rete ridges, rare intramalpighian apoptic keratinocytes and deposits of amorphous material in the superficial dermis. Examination under ultraviolet light showed thioflavin T-positive staining, confirming the presence of amyloid in the papillary dermis. The use of Capsaicin at the dilution of 0.025% had a mild efficacy on the cutaneous symptoms. CONCLUSIONS: Among the members of the three families with MEN 2A and RET 634 mutation, the incidence of CLA was 36%, a figure similar to that reported in the literature for phaeochromocytoma (30-50%) and even higher than that for hyperparathyroidism (10-20%). The present data confirm that CLA is linked to codon 634 RET mutations and is a precocious marker of the disorder. PMID: 12864791 [PubMed - indexed for MEDLINE] NR45: Endocr Pathol. 2003 Summer;14(2):123-31. Medullary thyroid carcinoma and multiple endocrine neoplasia type 2. Takami H. Department of Surgery, Teikyo University School of Medicine, Kaga, Tokyo, Japan. takami@med.teikyo-u.ac.jp Medullary thyroid carcinoma (MTC) occurs as both a sporadic and an inherited disease. MTC is a consistent feature of multiple endocrine neoplasia (MEN) 2A, MEN 2B, and familial non-MEN MTC (FMTC). Plasma calcitonin is a sensitive and specific marker for the presence of MTC. Genetic testing can identify mutant gene carriers, and prophylactic total thyroidectomy should be carried out in patients with the mutant gene. The outcome of MTC is progressively worse in FMTC, MEN 2A, sporadic MTC, and MEN 2B, and MEN 2B has been found to have the worst prognosis. There is a significant genotype-phenotype correlation, which allows a more sensitive individualized approach to the timing and extent of prophylactic thyroidectomy. Publication Types: Review Review, Tutorial PMID: 12858002 [PubMed - indexed for MEDLINE] DR46: J Surg Res. 2003 May 15;111(2):177-84. Focal adhesions and associated proteins in medullary thyroid carcinoma cells. Kim LT, Fleming JB, Lopez-Guzman C, Nwariaku F. Surgical Service, Central Arkansas Veterans Healthcare System and University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205, USA. BACKGROUND: In medullary thyroid carcinoma (MTC), mutations in the RET protooncogene lead to oncogenic transformation. RET activation in other cell types has been shown to cause phosphorylation of the focal adhesion-associated proteins focal adhesion kinase (FAK), paxillin, and p130(CAS). We hypothesized that adhesion-dependent signaling might be deranged in MTC cells. METHODS: Indirect immunofluorescence was used to label beta(1) integrin, FAK, paxillin, and p130CAS. Rhodamine-labeled phalloidin was used to visualize actin microfilaments. Phosphorylated protein was detected by immunoprecipitation followed by Western blotting for phosphotyrosine. MTC cell invasiveness was quantified using a modified Boyden chamber assay. RESULTS: Clustering of beta(1) integrin, FAK, paxillin, and p130(CAS) into focal adhesions were not detected in MTC cells under any conditions, although clustering was seen as expected in control HeLa cells. Despite this failure, FAK, paxillin and p130(CAS) were all found to be phosphorylated. Actin microfilaments were generally not seen although in a few cells, small, poorly formed microfilaments could be detected. MTC cells invaded poorly as compared with highly invasive cell lines. However a clear difference was noted between invasiveness on growth factor depleted Matrigel and regular Matrigel. CONCLUSIONS: In MTC cells, focal adhesions are not seen in response to interaction with extracellular matrix. Consistent with this failure, actin microfilaments are absent or poorly formed and invasion is weak. Despite the absence of focal adhesions, focal adhesion proteins remain phosphorylated, even though in normal cells their signaling activity is dependent on focal adhesion formation. Deranged adhesion-dependent signaling may contribute to MTC pathogenesis. PMID: 12850460 [PubMed - indexed for MEDLINE] DR47: J Endocrinol Invest. 2003 Apr;26(4):381-3. Comment on: J Endocrinol Invest. 2002 Jan;25(1):25-31. Does a somatic deletion in RET clarify the sporadic nature of medullary thyroid carcinoma? Gimm O, Marsh DJ. Publication Types: Comment Letter PMID: 12841548 [PubMed - indexed for MEDLINE] DR48: J Mol Med. 2003 Jul;81(7):411-9. Epub 2003 Jun 14. Gene therapeutic approaches for medullary thyroid carcinoma treatment. Drosten M, Putzer BM. Center for Cancer Research and Cancer Therapy, Institute of Molecular Biology, University of Essen Medical School, Hufelandstrasse 55, 45122 Essen, Germany. Medullary thyroid carcinoma (MTC), a neoplasm of thyroid C-cells, is characterized by dominant activating mutations in the RET proto-oncogene. Currently therapy is restricted to surgical removal of all neoplastic tissue lacking alternative forms of treatment such as chemotherapy or radiotherapy. Therefore MTC is a particularly attractive target for gene therapeutic approaches. Many promising gene therapy strategies have been used in various animal models of MTC, showing enhanced antitumoral efficacy, and these will hopefully extend our current standard of care in the future. These approaches can tentatively be subdivided into four groups: (a) Inhibition of oncogenic RET signaling, (b) suicide gene therapy, (c) immunotherapy, and (d) combination of immunotherapy and suicide approaches. To block oncogenic signal transduction dominant-negative RET mutants were delivered into tumor cells and found to possess strong antineoplastic activity, including tumor growth suppression and increased animal survival. Suicide gene therapeutic approaches applied to MTC treatment featured either gene transfer of herpes simplex virus thymidine kinase with concomitant application of ganciclovir or delivery of nitric oxide synthase II. Here antitumor effects were attributed to the occurrence of substantial bystander activities. Immunotherapy approaches comprised stimulation of immune response by delivery of interleukin 2 or 12. Finally, treatment with herpes simplex virus thymidine kinase/ganciclovir in combination with interleukin 2 was found to be superior over either treatment alone. This review discusses the various gene therapeutic approaches applied to MTC treatment in detail, gives an overview on the diverse vector systems used to achieve efficient transduction of thyroid cancer cells, and points out the strategies employed to accomplish target cell selective gene expression thereby contributing to enhanced safety of gene therapy for MTC Publication Types: Review Review, Tutorial PMID: 12811413 [PubMed - indexed for MEDLINE] DR49: J Clin Endocrinol Metab. 2003 Jun;88(6):2644-9. RET codon 634 mutations in multiple endocrine neoplasia type 2: variable clinical features and clinical outcome. Punales MK, Graf H, Gross JL, Maia AL. Endocrine Division, Hospital de Clinicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, Porto Alegre 90035-003, Rio Grande do Sul, Brazil. Since the establishment of a protocol for molecular analysis of hereditary medullary thyroid carcinoma (MTC) in southern Brazil, in 1997, 17 independent families with RET germline mutation have been identified. Because neither molecular diagnosis nor the pentagastrin test were available before the establishment of this protocol, we had the opportunity to observe a large number of patients in whom the disease has evolved naturally without medical intervention, namely prophylactic thyroidectomy. We observed a wide spectrum in terms of clinical presentation and natural course of the disease even among genetically related individuals. Sixty-nine individuals from 12 different families presented a codon 634 mutation, the most prevailing missense mutation in our series. The specific mutations identified were C634Y (n = 49), C634R (n = 13), and C634W (n = 7). Individuals with the C634R mutation presented significantly more distant metastases at diagnosis than subjects with the C634Y or C634W mutations (54.5% vs. 19.4% vs. 14.3%, respectively, P = 0.03). Further analysis of the estimated cumulative frequency of lymph node and/or distant metastases by Kaplan-Meier curves showed that the appearance of lymph nodes and metastases occurred later in patients with C634Y than in those with C634R (P = 0.001). Our results suggest that specific nucleotide and amino acid exchanges at codon 634 might have a direct impact on tumor aggressiveness in MEN 2A syndrome. PMID: 12788868 [PubMed - indexed for MEDLINE] DR50: Mutat Res. 2003 Jun 19;527(1-2):81-90. Novel tumorigenic rearrangement, Delta rfp/ret, in a papillary thyroid carcinoma from externally irradiated patient. Saenko V, Rogounovitch T, Shimizu-Yoshida Y, Abrosimov A, Lushnikov E, Roumiantsev P, Matsumoto N, Nakashima M, Meirmanov S, Ohtsuru A, Namba H, Tsyb A, Yamashita S. Department of International Health and Radiation Research, Nagasaki University School of Medicine, 1-12-4 Sakamoto, Nagasaki 852-8523, Japan. saenko@net.nagasaki-u.ac.jp Molecular analysis of cDNA derived from a papillary thyroid carcinoma (PTC) (follicular variant of papillary thyroid carcinoma on histology) which developed in an externally irradiated patient 4 years after exposure identified a portion of the 5' region, exons 1-3, of the rfp gene juxtaposed upstream of the fragment encoding the tyrosine kinase (TK) domain of the ret gene. The fusion gene, termed Delta rfp/ret, was the result of a balanced chromosomal translocation t(6;10) (p21.3;q11.2) confirmed by interphase FISH painting, with breakpoints occurring in introns 3 and 11 of the rfp and ret genes, respectively. Both Delta rfp/ret and reciprocal ret/rfp chimeric introns had small deletions around breakpoints consistent with presumed misrepair of a radiation-induced double-strand DNA break underlying the rearrangement. No extensive sequence homology was found between the fragments flanking the breakpoints. The fusion protein retained the propensity to form oligomers likely to be mediated by a coiled-coil of the RFP polypeptide as assessed by a yeast two-hybrid system. NIH 3T3 fibroblasts stably transfected with a mammalian expression vector encoding full-length Delta RFP/RET readily gave rise to the tumors in athymic mice suggestive of high transforming potential of the fusion protein. Thus, the Delta rfp/ret rearrangement may be involved in a causative manner in cancerogenesis and provides additional evidence of the role of activated ret oncogene in the development of a subset of papillary thyroid carcinoma. Publication Types: Case Reports PMID: 12787916 [PubMed - indexed for MEDLINE] DR51: J Intern Med. 2003 Jun;253(6):616-26. Surgical treatment of medullary thyroid carcinoma. Cohen MS, Moley JF. Department of Surgery, Washington University School of Medicine, St Louis, MO, USA. cohenm@msnotes.wustl.edu Medullary thyroid carcinoma (MTC) is a malignancy of the parafollicular C cells of the thyroid gland. It occurs sporadically or as part of the multiple endocrine neoplasia type 2 (MEN 2) syndromes. Patients who have inherited a mutation in the RET proto-oncogene should have thyroidectomy early in life to prevent formation and spread of this cancer. Most patients with sporadic disease present with a palpable neck mass. The diagnosis is made by fine needle aspiration biopsy and by measuring calcitonin levels in the blood. Primary treatment consists of surgical resection including a total thyroidectomy, central neck nodal dissection and functional lateral neck nodal dissections. Most patients with a palpable primary tumour have nodal disease present at the time of operation, and nodal involvement is often bilateral. Adequate resection of the primary tumour and cervical lymph nodes is important to optimize outcome and minimize the risk of recurrent disease. Proper handling of the parathyroid glands prevents hypoparathyroidism. Following primary surgical resection, more than half of the patients will have recurrent disease with persistent elevation of calcitonin levels. Currently, there is no adequate systemic therapy for treating recurrent disease. Surgical reoperation or conservative observation are the best available options. Diagnostic laparoscopy for liver evaluation is the most sensitive diagnostic test to detect the presence of distant metastases. PMID: 12755957 [PubMed - indexed for MEDLINE] DR52: Endocr Pathol. 2003 Spring;14(1):71-80. Penetrance of inherited medullary thyroid carcinoma and genotype-phenotype correlation in a large multiple endocrine neoplasia type 2A family with C634Y RET mutation. Gonzalez-Yebra B, Medrano ME, Mantilla A, Palma V, Colin C, Hernandez DM, Tapia J, Dawson B, Salcedo M. Oncology Hospital, Oncology Research Unit, National Medical Center SXXI-IMSS, Mexico, D.F., Mexico. Multiple endocrine neoplasia type 2A (MEN 2A) and familial medullary thyroid carcinoma (FMTC) are characterized by development of medullary thyroid carcinoma (MTC) and caused by germline RET mutations. Patients with MEN 2A also develop pheochromocytoma and/or hyperparathyroidism (HPT). However, MEN 2A-affected individuals could display the FMTC phenotype at first clinical manifestation. To establish the correct phenotype and improve clinical management of patients affected by hereditary MTC, clinical screening, RET mutational analysis, penetrance of MTC, and genotype-phenotype correlation were performed in a large, suspected FMTC kindred of 86 individuals. Germline C634Y RET mutation was confirmed in 22 individuals, 15 of whom were thyroidectomized when high serum calcitonin levels were detected. MTC was confirmed in 12 individuals and C-cell hyperplasia in 3. HPT was detected in two patients. High penetrance of MTC at young age (79% at 30 yr of age) was found. This family was considered to be affected by FMTC for several years because MTC was the sole clinical manifestation. However, our results allowed reclassifying the family as MEN 2A, thereby improving clinical management of family members. Our findings regarding penetrance and genotype-phenotype correlation suggest that patients considered to have FMTC may in fact have MEN 2A in some kindreds. PMID: 12746565 [PubMed - indexed for MEDLINE] DR53: Eur J Hum Genet. 2003 May;11(5):364-8. Cys611Ser mutation in RET proto-oncogene in a kindred with medullary thyroid carcinoma and Hirschsprung's disease. Nishikawa M, Murakumo Y, Imai T, Kawai K, Nagaya M, Funahashi H, Nakao A, Takahashi M. Department of Pathology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan. Germline mutations in the RET proto-oncogene are responsible for the development of human hereditary diseases, including multiple endocrine neoplasia (MEN) type 2A and 2B, familial medullary thyroid carcinoma (FMTC), and Hirschsprung's disease (HSCR). It has been reported that some families developed both MEN 2A/FMTC and HSCR, in which a mutation in a cysteine residue at codon 609, 618, or 620 in the RET gene was present. Here we report a novel RET mutation detected in a Japanese family with medullary thyroid carcinoma and HSCR. A germline mutation in cysteine 611 of the RET gene was identified in this family, which introduced an amino-acid change from cysteine to serine. By biological and biochemical analyses of mutant RET proteins, we previously predicted the potentiality that amino-acid substitution for cysteine 611 as well as cysteines 609, 618, and 620 would promote the development of MEN 2A/FMTC and HSCR. This clinical case substantiates our suggestion for the mechanism of the development of both the diseases. Publication Types: Case Reports PMID: 12734540 [PubMed - indexed for MEDLINE] DR54: Pediatr Surg Int. 2003 Apr;19(1-2):62-4. Epub 2003 Mar 21. Multiple endocrine neoplasias type 2A and thyroid medullary carcinoma: an interdisciplinary challenge. Haecker FM, Oertli D, Gissler S, Zumsteg U, Avoledo P, von Schweinitz D. Department of Pediatric Surgery, University Children's Hospital, P.O. Box, CH 4005 Basel, Switzerland. haeckerfm_ukbb@web.de The diagnosis and treatment of multiple endocrine neoplasias type 2A (MEN 2A) requires interdisciplinary management. The association of RET proto-oncogene mutations and medullary thyroid carcinoma (MTC) in children is well-known, but the optimal timing for elective surgery is controversial. Besides the risk of MTC, associated anomalies like hyperparathyroidism have to be considered. We report the results of molecular genetic investigations, the pentagastrin stimulation test, pre- and postoperative staging, and histologic examinations of four children who had a positive family history for MEN 2A. Histologic specimens of the removed thyroid glands showed MTC in all four cases. The patients had an uneventful postoperative clinical course. In view of the recent literature and our patients' results, we suggest a concept for diagnostic strategy and timing of the elective thyroidectomy. PMID: 12721726 [PubMed - indexed for MEDLINE] DR55: Eur J Surg Oncol. 2003 May;29(4):331-5. Acceptable age for prophylactic surgery in children with multiple endocrine neoplasia type 2a. Kahraman T, de Groot JW, Rouwe C, Hofstra RM, Links TP, Sijmons RH, Plukker JT. Department of Surgical Oncology/Head and Neck Surgery, University Hospital Groningen, Groningen, The Netherlands. j.th.plukker@chir.azg.nl AIMS: Germline mutated RET proto-oncogene, causing multiple endocrine neoplasia (MEN)-2a syndrome is the indication for prophylactic total thyroidectomy. Literature regarding the risk and the extent of early surgical intervention is scarce and the optimum age for surgery is still controversial. To optimize management in these young children we evaluate our experience and results. PATIENTS AND METHODS: From 1990 to 2001 preventive total thyroidectomy was performed in 13 MEN-2a gene carriers (4 boys and 9 girls; median age 7 (4-14) years). Preoperative assessment, surgical procedure, pathological examination, postoperative complications and treatment results were studied. RESULTS:Surgery existed of a total thyroidectomy alone (n=3) in children with normal basal calcitonin and in combination with tracheo-esophageal exploration (n=6) or central compartment dissection (n=4) in case of abnormal calcitonin levels. Eight children presented with medullary thyroid cancer (MTC), three (median: 5 (4-12) years) with microscopic MTC and five (median 6 (4-14) years) with frank invasive MTC. Four of these five patients were younger than 6 years. Except for long-lasting hypoparathyroidism in one patient there were no complications. At a median follow-up of 6.5 years all patients are disease free. CONCLUSION: MTC in RET mutated MEN-2a gene carriers in childhood are found at the age of 4 years. Therefore, DNA testing should be done preferably before that age. Preventive surgery can be performed safely at that age and may be limited to total thyroidectomy when baseline calcitonin levels are normal. PMID: 12711285 [PubMed - indexed for MEDLINE] PR56: Ann Endocrinol (Paris). 2003 Feb;64(1):62-3. Genetic alterations in differentiated thyroid cancer: what can be expected for gene expression profiling of thyroid carcinomas. Santoro M, Melillo RM, Carlomagno F, Castellone MD, Vitagliano D, Guida T, Vecchio G, Fusco A. Centro di Endocrinologia ed Oncologia Sperimentale del C.N.R., 80131 Napoli-Italy. Publication Types: Review Review, Tutorial PMID: 12707638 [PubMed - indexed for MEDLINE] DR57: Cancer Res. 2003 Apr 15;63(8):1814-7. Polymorphisms G691S/S904S of RET as genetic modifiers of MEN 2A. Robledo M, Gil L, Pollan M, Cebrian A, Ruiz S, Azanedo M, Benitez J, Menarguez J, Rojas JM. Centro Nacional de Epidemiologia, Instituto de Salud Carlos III; Centro Nacional de Investigaciones Oncologicas, Madrid, Spain. Multiple endocrine neoplasia type 2A (MEN 2A) is associated with specific germ-line missense mutations in the RET proto-oncogene. Only a minor fraction of human disorders are simple monogenic diseases, and the identification of polymorphisms that increase susceptibility, including variations in pathological phenotypes, to human diseases is one of the key problems in medical genetics. To explore this idea, we analyzed the polymorphisms G691S (exon 11) and S904S (TCC-TCG, exon 15) of RET in 198 individuals corresponding to 35 unrelated Spanish MEN 2A families (104 patients with oncogenic MEN 2A mutation and 94 healthy relatives). We found strong cosegregation between both polymorphisms (100% Fisher's exact test, P < 0.001) using a control population containing 653 healthy individuals (362 females and 291 males). Interestingly, we found that the homozygous for these polymorphisms were, on average, 10 years younger at diagnosis compared with heterozygous and wild-type homozygous (P = 0.037). Taken together, all these findings could indicate that the G691S and S904S variants of RET have a modifier effect on the age at onset of MEN 2A. Moreover, compared with the control population, the homozygote status was significantly more prevalent in a series of 110 sporadic thyroid carcinoma (odds ratio = 2.36), suggesting that these polymorphisms may play a role as a low penetrance risk factor. PMID: 12702567 [PubMed - indexed for MEDLINE] DR58: Clin Genet. 2003 Mar;63(3):219-23. Segregation of the V804L mutation and S836S polymorphism of exon 14 of the RET gene in an extended kindred with familial medullary thyroid cancer. Patocs A, Valkusz Z, Igaz P, Balogh K, Toth M, Varga I, Racz K. 2nd Department of Medicine, Faculty of Medicine, Semmelweis University, Szentkiralyi 46, H-1088 Budapest, Hungary. In multiple endocrine neoplasia type 2A (MEN 2A) and familial medullary thyroid cancer (FMTC), the majority of germline mutations are restricted to specific positions in exons 10 and 11 of the RET gene. However, germline mutations may very occasionally occur in other exons, including exon 14 of the RET gene. Interestingly, an increased frequency of a rare germline sequence variant of the RET exon 14, S836S, has been detected in patients with sporadic medullary thyroid cancer (MTC), and this variant has been proposed to play a role in the genesis of MTC and, perhaps, FMTC. In this study we report the segregation of a germline V804L mutation and a germline sequence variant S836S in exon 14 of the RET gene in an extended Hungarian FMTC kindred comprising 80 individuals of four generations. Molecular analysis of the RET gene was performed by direct DNA sequencing in 23 family members, of whom 12 had the V804L mutation, three had the V804L mutation and S836S polymorphism in separate alleles, and six had the S836S polymorphism, all in heterozygous forms. Two of the family members had neither mutation nor polymorphism of the RET gene. Three of the family members who had the V804L mutation and one member who could not be tested for mutation were operated for non-metastatic MTC, while one member with MTC who had the V804L mutation refused surgery. In all patients affected with MTC, the disease developed relatively late in life and never caused death. None of the other family members carrying the V804L mutation and/or the S836S polymorphism had clinical or biochemical evidence of MTC. These observations suggest that the co-existence of the V804L mutation and S836S polymorphism in separate alleles does not seem to aggravate the relatively low-risk disease phenotype characteristic in most patients with codon 804 mutations of the RET exon 14. Copyright Blackwell Munksgaard, 2003 PMID: 12694233 [PubMed - indexed for MEDLINE] DR59: Langenbecks Arch Surg. 2003 Mar;388(1):17-26. Epub 2003 Mar 25. Prophylactic thyroidectomy in multiple endocrine neoplasia: the impact of molecular mechanisms of RET proto-oncogene. Frilling A, Weber F, Tecklenborg C, Broelsch CE. Klinik fur Allgemein- und Transplantationschirurgie, Universitatsklinikum Essen, Hufelandstrasse 55, 45122 Essen, Germany. frilling@uni-essen.de BACKGROUND: Multiple endocrine neoplasia (MEN) type 2, a cancer syndrome inherited in the dominant fashion, is defined by the occurrence of medullary thyroid carcinoma (MTC), either as a singular lesion (familial medullary thyroid carcinoma, FMTC) or with the variable expression of pheochromocytoma, hyperparathyroidism (MEN 2A), ganglioneuromas, buccal neuromas and Marfanoid-like phenotype (MEN 2B). DISCUSSION: Germline mutations of the RET proto-oncogene, localized on chromosome 10q11.2, have been identified as the underlying genetic cause of the disorder. In the majority of patients with MEN 2A/FMTC missense mutations at exon 10 or exon 11 are identifiable. Cysteine to arginine exchange at codon 634 is the mutation most frequently found. In MEN 2B approximately 95% of patients present with a mutation at codon 918 (exon 16). Additionally, less frequent mutations in other codons have been found in both syndromes. The DNA-based genotype analysis enables the identification of gene carriers at risk of developing MTC and offer them prophylactic thyroidectomy prior to development of any thyroid pathologies. Prophylactic surgery is generally recommended for MEN 2A/FMTC gene carriers at the age of 4-6 years. Due to the aggressiveness of the MEN 2B syndrome gene carriers should be operated by the age of 1 year. Presumably some less virulent mutations allow postponement of the prophylactic treatment to the second to fourth decade of life. CONCLUSIONS: Compared to standard presymptomatic biochemical screening, genetic testing and consecutive prophylactic treatment contribute to better outcome of individuals at risk for MTC. Publication Types: Review Review, Tutorial PMID: 12690476 [PubMed - indexed for MEDLINE] DR60: Mol Endocrinol. 2003 Jul;17(7):1425-36. Epub 2003 Apr 10. Conditional expression of RET/PTC induces a weak oncogenic drive in thyroid PCCL3 cells and inhibits thyrotropin action at multiple levels. Wang J, Knauf JA, Basu S, Puxeddu E, Kuroda H, Santoro M, Fusco A, Fagin JA. Division of Endocrinology and Metabolism, University of Cincinnati College of Medicine, Ohio 45267-0547, USA. Chromosomal rearrangements linking the promoter(s) and N-terminal domain of unrelated gene(s) to the C terminus of RET result in constitutively activated chimeric forms of the receptor in thyroid cells (RET/PTC). RET/PTC rearrangements are thought to be tumor-initiating events; however, the early biological consequences of RET/PTC activation are unknown. To explore this, we generated clonal lines derived from well-differentiated rat thyroid PCCL3 cells with doxycycline-inducible expression of either RET/PTC1 or RET/PTC3. As previously shown in other cell types, RET/PTC1 and RET/PTC3 oligomerized and displayed constitutive tyrosine kinase activity. Neither RET/PTC1 nor RET/PTC3 conferred cells with the ability to grow in the absence of TSH, likely because of concomitant stimulation of both DNA synthesis and apoptosis, resulting in no net growth in the cell population. Effects of RET/PTC on DNA synthesis and apoptosis did not require direct interaction of the oncoprotein with either Shc or phospholipase Cgamma. Acute expression of the oncoprotein decreased TSH-mediated growth stimulation due to interference of TSH signaling by RET/PTC at multiple levels. Taken together, these data indicate that RET/PTC is a weak tumor-initiating event and that TSH action is disrupted by this oncoprotein at several points, and also predict that secondary genetic or epigenetic changes are required for clonal expansion. PMID: 12690093 [PubMed - indexed for MEDLINE] DR61: Arch Surg. 2003 Apr;138(4):409-16; discussion 416. Multiple endocrine neoplasia type 2: evaluation of the genotype-phenotype relationship. Yip L, Cote GJ, Shapiro SE, Ayers GD, Herzog CE, Sellin RV, Sherman SI, Gagel RF, Lee JE, Evans DB. Department of Surgical Oncology, The University of Texas M. D. Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, TX 77030, USA. HYPOTHESIS: Multiple endocrine neoplasia type 2 (MEN 2) is caused by RET proto-oncogene mutations and has a strong penetrance for medullary thyroid carcinoma (MTC). Subtypes are defined by the presence or absence of pheochromocytomas, hyperparathyroidism, and characteristic clinical stigmas. We hypothesize that specific RET mutations correlate with the MEN 2 phenotype and aggressiveness of MTC. DESIGN: Review of endocrine surgery database from 1951 through 2002. SETTING: Tertiary referral center. PATIENTS: Eighty-six patients from 47 kindreds were identified with MEN 2A, MEN 2B, or familial MTC. Patients were classified into 3 RET mutation risk groups: level 1, low risk for MTC (codons 609, 768, 790, 791, 804, and 891); level 2, intermediate risk (codons 611, 618, 620, and 634); and level 3, highest risk (codons 883 and 918). MAIN OUTCOME MEASURES: Stage of MTC at diagnosis and at last follow-up and frequency of pheochromocytomas and hyperparathyroidism. RESULTS: RET analysis was complete for 71 patients from 39 kindreds. Multivariate analysis identified an increased likelihood of stage III or IV MTC at diagnosis with increasing age (odds ratio, 1.12 per year of age at thyroidectomy; 95% confidence interval, 1.07-1.17; P<.001) and increasing risk group (odds ratio, 14.23 per incremental increase in MTC risk group from 1 to 3; 95% confidence interval, 3.05-66.55; P<.001). Pheochromocytomas were found in 21 patients from 12 kindreds; 20 of 21 patients had codon 634 or 918 mutations. Hyperparathyroidism was found in 10 patients from 7 kindreds; 7 of 10 patients had codon 634 mutations. CONCLUSION: Specific RET mutations predict the phenotypic expression of disease and the MTC aggressiveness in patients with MEN 2, guiding the timing of thyroidectomy and screening for pheochromocytoma. PMID: 12686527 [PubMed - indexed for MEDLINE] DR62: J Clin Endocrinol Metab. 2003 Apr;88(4):1897-902. Efficient inhibition of RET/papillary thyroid carcinoma oncogenic kinases by 4-amino-5-(4-chloro-phenyl)-7-(t-butyl)pyrazolo[3,4-d]pyrimidine (PP2). Carlomagno F, Vitagliano D, Guida T, Basolo F, Castellone MD, Melillo RM, Fusco A, Santoro M. Istituto di Endocrinologia ed Oncologia Sperimentale del Consiglio Nazionale delle Ricerche c/o Dipartimento di Biologia e Patologia Cellulare e Molecolare L. Califano, Universita Federico II, 80131 Naples, Italy. Inappropriate activation of the RET receptor tyrosine kinase causes development of papillary and medullary thyroid cancer. We have previously shown that pyrazolopyrimidine is a potent inhibitor of the RET kinase. Here, we show that 4-amino-5-(4-chloro-phenyl)-7-(t-butyl)pyrazolo[3,4-d]pyrimidine) (PP2), another pyrazolopyrimidine, blocks the enzymatic activity of the isolated RET kinase and RET/PTC1 oncoprotein at IC(50) in the nanomolar range. PP2 blocked in vivo phosphorylation and signaling of the RET/PTC1 oncoprotein. PP2 prevented serum-independent growth of RET/PTC1-transformed NIH3T3 fibroblasts and of TPC1 and FB2, two human papillary thyroid carcinoma cell lines that carry spontaneous RET/PTC1 rearrangements. Finally, PP2 blocked invasion of type I collagen matrix by TPC1 cells. Thus, pyrazolopirimidines hold promise for the treatment of human cancers sustaining oncogenic activation of RET. PMID: 12679489 [PubMed - indexed for MEDLINE] DR63: J Clin Endocrinol Metab. 2003 Apr;88(4):1866-72. Genome-wide copy number imbalances identified in familial and sporadic medullary thyroid carcinoma. Marsh DJ, Theodosopoulos G, Martin-Schulte K, Richardson AL, Philips J, Roher HD, Delbridge L, Robinson BG. Cancer Genetics, Kolling Institute of Medical Research, and Pacific Laboratory Medicine Services, Royal North Shore Hospital, St. Leonards, New South Wales 2065, Australia. debbie_marsh@med.usyd.edu.au Medullary thyroid carcinoma (MTC) is a malignant tumor of the calcitonin-secreting parafollicular C cells of the thyroid occurring sporadically and as a component of the multiple endocrine neoplasia type 2/familial medullary thyroid carcinoma syndrome. The primary genetic cause of multiple endocrine neoplasia type 2 is germline mutation of the RET protooncogene. Somatic point mutations in RET also occur in sporadic MTC. Although RET mutation is likely sufficient to cause C-cell hyperplasia, the precursor lesion to MTC, tumor progression is thought to be due to clonal expansion caused by the accumulation of somatic events. Using the genome-scanning technique comparative genomic hybridization, we identified chromosomal imbalances that occur in MTC including deletions of chromosomes 1p, 3q26.3-q27, 4, 9q13-q22, 13q, and 22q and amplifications of chromosome 19. These regions house known tumor suppressor genes as well as genes encoding subunits of the multicomponent complex of glycosylphosphatidylinositol-linked proteins (glial cell line-derived neurotrophic factor family receptors alpha-2-4) and their ligands glial cell line-derived neurotrophic factor, neurturin, persephin, and artemin that facilitate RET dimerization and downstream signaling. Chromosomal imbalances in the MTC cell line TT were largely identical to those identified in primary MTC tumors, consolidating its use as a model for studying MTC. PMID: 12679485 [PubMed - indexed for MEDLINE] NR64: J Ky Med Assoc. 2003 Mar;101(3):100-7. Molecular genetics and management strategies in hereditary cancer syndromes. Hanna NN, Mentzer RM Jr. University of Kentucky Medical Center, Lexington, KY 40536. nhanna1@uky.edu The origin, characteristics, and lifetime risk for the following five types of hereditary cancer (HCS) syndromes are briefly described in this review: hereditary breast and ovarian cancer (HBOC) syndrome, familial adenomatous polyposis (FAP), and hereditary nonpolyposis colorectal cancer (HNPCC) syndrome, hereditary diffuse gastric cancer (HDGC) syndrome, and medullary thyroid carcinoma (MTC). Most are caused by mutations in tumor suppressor genes. In HCS, a single copy of the mutated tumor suppressor gene is inherited, and mutation of the second wild type allele of the gene is required for tumorigenesis. Patients with HCS have a higher than normal risk of a second malignancy. Management strategies to address increased cancer risk in HCS include genetic counseling and testing, targeted surveillance, chemoprevention, and prophylactic surgery. Genetic testing for high-risk family members is strongly recommended. Available data indicate surgical prophylaxis is more successful than surveillance in reducing cancer risk in carriers of BRCA, CDH1, APC, and RET mutation. Publication Types: Review Review, Tutorial PMID: 12674901 [PubMed - indexed for MEDLINE] DR65: Medicina (B Aires). 2003;63(1):41-5. [Study of RET protooncogene in multiple endocrine neoplasm 2A and in familial medullary thyroid carcinoma. Clinical pathological findings in asymptomatic carriers] [Article in Spanish] Belli S, Storani ME, Dourisboure RJ, Podesta EJ, Solano AR. Instituto Alexander Fleming, Division de Endocrinologia-Hospital Durand. Twenty five percent of the medullary thyroid carcinoma (MTC) is hereditary and 5% is familiar (FMTC), or considered as multiple endocrine neoplasia (MEN) type 2A (17%) or 2B (3%). These diseases are the result of the autosomic dominant inheritance of a mutation in the RET protooncogene, in one out of 12 different known codons. We analyzed 7 families (2 MEN 2A and 5 FMTC). Six mutations were detected in the most frequent codon, 634 (2 MEN 2A y 4 FMTC) and one family with FMTC presented a novel mutation: a transition T > C at codon 630, resulting a C630A change. Among 57 individuals studied, 25 (43.85%) presented the mutation. Seven (28%) were asymptomatic carriers, including 5 children aged 11 +/- 3.2 years. The children underwent total thyroidectomy. The histopathologic examination showed C cells hyperplasia and microcarcinoma focus in both lobes, even in the presence of normal, basal or pentagastrine stimulated, calcitonine levels. In conclusion, we describe a germine novel mutation in the RET protooncogene: C630A; and the corresponding findings of C-cell disease in gene mutated carriers that emphasize the importance of prophylactic thyroidectomy as soon as the molecular diagnosis is confirmed. PMID: 12673960 [PubMed - indexed for MEDLINE] DR66: Cancer Res. 2003 Apr 1;63(7):1454-7. High prevalence of BRAF mutations in thyroid cancer: genetic evidence for constitutive activation of the RET/PTC-RAS-BRAF signaling pathway in papillary thyroid carcinoma. Kimura ET, Nikiforova MN, Zhu Z, Knauf JA, Nikiforov YE, Fagin JA. Division of Endocrinology and Metabolism, University of Cincinnati College of Medicine, Cincinnati, Ohio 45267, USA. Thyroid papillary cancers (PTCs) are associated with activating mutations of genes coding for RET or TRK tyrosine kinase receptors, as well as of RAS genes. Activating mutations of BRAF were reported recently in most melanomas and a small proportion of colorectal tumors. Here we show that a somatic mutation of BRAF, V599E, is the most common genetic change in PTCs (28 of 78; 35.8%). BRAF(V599E) mutations were unique to PTCs, and not found in any of the other types of differentiated follicular neoplasms arising from the same cell type (0 of 46). Moreover, there was no overlap between PTC with RET/PTC, BRAF, or RAS mutations, which altogether were present in 66% of cases. The lack of concordance for these mutations was highly unlikely to be a chance occurrence. Because these signaling proteins function along the same pathway in thyroid cells, this represents a unique paradigm of human tumorigenesis through mutation of three signaling effectors lying in tandem. PMID: 12670889 [PubMed - indexed for MEDLINE] DR67: Endocr Pathol. 2002 Winter;13(4):321-30. Loss of heterozygosity mutations of tumor suppressor genes in cytologically atypical areas in chronic lymphocytic thyroiditis. Hunt JL, Baloch ZW, Barnes L, Swalsky PA, Trusky CL, Sesatomi E, Finkelstein S, LiVolsi VA. University of Pittsburgh, Medical Center, Pittsburgh, PA 15213, USA. HUNTJL@msx.upmc.edu The relationship between chronic lymphocytic thyroiditis (CLT) and papillary thyroid carcinoma (PTC) is a subject of controversy. Some investigators suggest a causal relationship, whereas others regard the two as only a coincidental occurrence. An additional complicating factor is the presence of atypical nuclei frequently found within lymphoid infiltrates in CLT, which resemble those in PTC. The finding of the RET-PTC translocations in CLT has been reported by two independent groups of investigators, suggesting that the areas of nuclear atypia in CLT are neoplastic rather than reactive. In the present study, we report additional molecular findings that support the hypothesis that the atypical nuclear changes in CLT may be preneoplastic or neoplastic. We microdissected small areas with atypical nuclei in glands with CLT and observed loss-of-heterozygosity mutations of tumor suppressor genes. These genetic mutations are evidence of clonal preneoplastic or neoplastic changes in the follicular cells of CLT. The clinical malignant potential of these minute foci is likely to be very small but remains to be determined. PMID: 12665650 [PubMed - indexed for MEDLINE] DR68: Endocr Pathol. 2002 Winter;13(4):289-99. Etiology and significance of the optically clear nucleus. Baloch ZW, LiVolsi VA. Department of Pathology and Laboratory Medicine, University of Pennsylvania medical Center, PA 19104, USA. baloch@mail.med.upenn.edu Papillary thyroid carcinoma (PTC) is diagnosed in both cytology and surgical pathology specimens on the basis of distinct nuclear morphology, characterized by nuclear elongation, chromatin clearing, intranuclear grooves, and inclusions. Although these nuclear features are specific to papillary carcinoma, they can be mimicked in some benign conditions. The majority of PTC cases do not pose diagnostic problems. However, a distinct subset of cases has generated controversy among experts. These cases are follicular patterned tumors that show minimal nuclear changes in PTC. Several investigators have explored the role of immunohistochemical markers in the histologic diagnosis of PTC. Somatic rearrangements of the RET protooncogene are the most frequent genetic abnormality found in PTC. The frequency of these rearrangements has varied according to the geographic region, radiation exposure, and methodologies used and histologic variant of PTC. Recent studies have suggested that RET/PTC may be the cause of this specific nuclear change in PTC; however, the role of RET/PTC in tumor progression still needs to be defined. Publication Types: Review Review, Tutorial PMID: 12665647 [PubMed - indexed for MEDLINE] DR69: Endocr Pathol. 2002 Winter;13(4):271-88. Molecular pathobiology of thyroid neoplasms. Tallini G. Department of Pathology Yale University School of Medicine, New Haven, CT 06510, USA. tallini@yale.edu Tumors of thyroid follicular cells provide a very interesting model to understand the development of human cancer. It is becoming apparent that distinct molecular events are associated with specific stages in a multistep tumorigenic process with good genotype/ phenotype correlation. For instance, mutations of the gsp and thyroid-stimulating hormone receptor genes are associated with benign hyperfunctioning thyroid nodules and adenomas while alterations of other specific genes, such as oncogenic tyrosine kinase alterations (RET/PTC, TRK) in papillary carcinoma and the newly discovered PAX8/peroxisome proliferator-activated receptor gamma rearrangement, are distinctive features of cancer. Although activating RAS mutations occur at all stages of thyroid tumorigenesis, evidence is accumulating that they may also play an important role in tumor progression, a role that is well documented for p53. Environmental factors (iodine deficiency, ionizing radiations) have been shown to play a crucial role in promoting the development of thyroid cancer, influencing both its genotypic and phenotypic features. It is possible that the follicular thyroid cell has unique ways to respond to DNA damage. Similarly to leukemia or sarcomas (and unlike most epithelial cancers), numerous specific rearrangements are being discovered in thyroid cancer suggesting preferential activation of DNA repair instead of cell death programs after environmentally induced genetic alterations. Publication Types: Review Review, Tutorial PMID: 12665646 [PubMed - indexed for MEDLINE] DR70: South Med J. 2003 Mar;96(3):287-90. Pediatric medullary carcinoma of the thyroid with point mutation of RET proto-oncogene associated with multiple endocrine neoplasia and initially diagnosed by fine-needle aspiration biopsy. Chai C, Lemos LB, Kaelbling M, Baliga M. Department of Pathology, University of Mississippi Medical Center, Jackson, MS, USA. A 7-year-old girl presented with a thyroid mass, elevated serum levels of calcitonin and carcinoembryonic antigen, as well as multiple mucosal nodules in the upper lip and tongue. Cytologic material obtained by fine-needle aspiration biopsy from the thyroid mass was diagnosed as medullary carcinoma and confirmed by immunohistochemical studies in the cell-block sections. Subsequent histopathologic examination showed involvement of both thyroid lobes by medullary carcinoma, and electron microscopic studies further confirmed the diagnosis. Molecular studies showed a point mutation in amino acid 918 in exon 16 of the RET proto-oncogene. Biopsies from the upper lip and tongue showed mucosal neuromas. Fine-needle aspiration biopsy is frequently used in the initial evaluation of thyroid nodules. This case illustrates the value of fine-needle aspiration biopsy as a safe and accurate diagnostic modality in the workup of pediatric thyroid nodules. Fine-needle aspiration biopsy should always be considered for the investigation of thyroid nodules in pediatric patients. Publication Types: Case Reports PMID: 12659362 [PubMed - indexed for MEDLINE] DR71: J Cell Physiol. 2003 May;195(2):168-86. RET and NTRK1 proto-oncogenes in human diseases. Alberti L, Carniti C, Miranda C, Roccato E, Pierotti MA. Operative Unit Molecular Mechanisms of Tumor Growth and Progression, Department of Experimental Oncology, Istituto Nazionale Tumori, Milan, Italy. RET and NTRK1 are receptor tyrosine kinase (RTK) proteins which play a role in the development and maturation of specific component of the nervous system. Their alterations have been associated to several human diseases, including some forms of cancer and developmental abnormalities. These features have contributed to the concept that one gene can be responsible for more than one disease. Moreover, both genes encoding for the two RTKs show genetic alterations that belong to either "gain of function" or "loss of function" class of mutations. In fact, receptor rearrangements or point mutations convert RET and NTRK1 in dominantly acting transforming genes leading to thyroid tumors, whereas inactivating mutations, associated with Hirschsprung's disease (HSCR) and congenital insensitivity to pain with anhidrosis (CIPA), impair RET and NTRK1 functions, respectively. In this review we have summarized the main features of the two receptors, their physiological and pathological roles. In addition, we attempted to identify the correlations between the different genetic alterations and the related pathogenetic mechanisms. Copyright 2003 Wiley-Liss, Inc. Publication Types: Review PMID: 12652644 [PubMed - indexed for MEDLINE] DR72: Cancer Genet Cytogenet. 2003 Mar;141(2):157-9. Multiple endocrine neoplasia type 2A: an unusual clinical presentation and association with renal dysplasia. McIntyre E, Bond P, Douglas F, Lennard T, Peaston R, Perros P. Endocrine Unit, Freeman Hospital, Newcastle upon Tyne, UK. We report what we believe to be the first case of a patient with multiple endocrine neoplasia type 2A (MEN 2A) and renal dysplasia associated with an RET 634 mutation. The proband presented at the age of 29 with medullary thyroid carcinoma (MTC), bilateral pheochromocytomas, and primary hyperparathyroidism. Screening of family members identified the syndrome in his father. Both the proband and his father carry RET 634 germline mutation resulting in cysteine to arginine amino acid substitution. The proband had a left nephrectomy at the age of 10 years. Histologic examination of the resected kidney revealed severe dysplasia. His father had normal renal tract on ultrasonography. The proband's clinical presentation was unusual, and initially thought to be an atypical pneumonia. Surgical management after pharmacologic alpha- and beta-blockage consisted of bilateral adrenalectomy, total thyroidectomy, and subtotal parathyroidectomy as a single procedure. Publication Types: Case Reports PMID: 12606135 [PubMed - indexed for MEDLINE] DR73: Arch Med Res. 2003 Jan-Feb;34(1):41-9. RET oncogene mutations in medullary thyroid carcinoma in Mexican families. Gonzalez B, Salcedo M, Medrano ME, Mantilla A, Quinonez G, Benitez-Bribiesca L, Rodriguez-Cuevas S, Cabrera L, de Leon B, Altamirano N, Tapia J, Dawson B. Unidad de Investigacion Medica en Enfermedades Oncologicas, Instituto Mexicano del Seguro Social (IMSS), Mexico City, Mexico. BACKGROUND: Different RET oncogene mutations have been found to be associated with inherited medullary thyroid carcinoma (MTC) in the context of three different syndromes including multiple endocrine neoplasia types 2A (MEN 2A) and 2B (MEN 2B) and familial medullary thyroid carcinoma (FMTC). These mutations have been recorded in different populations, but to date there is no corresponding study in Mexican families. Our purpose was identification of RET mutations in Mexican families with inherited or sporadic MTC (SMTC) and search for RET protein expression as prognostic marker in MTC tumors. METHODS: Nine unrelated families with MTC corresponding either to two MEN 2A, three MEN 2B, or four SMTC were studied. Screening of exons 10, 11, and 13-16 of RET oncogene in DNA from circulating lymphocytes and tumor samples were analyzed. Immuno- staining for RET was performed in the corresponding tumor. RESULTS: Germline 918 ATG-->ACG RET mutation was present in three unrelated MEN 2B individuals and corresponding somatic mutation in one individual with SMTC; 634 TGC-->TTC RET mutation was detected in two related patients in an MEN 2A family and the 634 TGC-->TAC RET mutation was detected in 12 related individuals from a second MEN 2A family. RET protein expression was detected in all MTC tumors showing different staining intensity. CONCLUSIONS: RET mutations found in Mexican patients with MTC are similar to those previously reported in several MTC families worldwide. This indicates that RET mutations are highly conserved and that MTC etiology does not depend to a great extent on environmental factors or ethnic differences. Detection of RET protein in MTC tissue sections is not useful as prognostic marker. PMID: 12604374 [PubMed - indexed for MEDLINE] NR74: J Clin Endocrinol Metab. 2003 Feb;88(2):748-54. Analysis of cancer/testis antigens in sporadic medullary thyroid carcinoma: expression and humoral response to NY-ESO-1. Maio M, Coral S, Sigalotti L, Elisei R, Romei C, Rossi G, Cortini E, Colizzi F, Fenzi G, Altomonte M, Pinchera A, Vitale M. Cancer Bioimmunotherapy Unit, Department of Medical Oncology, Centro di Riferimento Oncologico, Istituto di Ricovero e Cura a Carattere Scientifico, 33081 Aviano, Italy. Cancer/testis antigens (CTA) are tumor-associated antigens expressed during ontogenesis, in a number of solid tumors but not in normal tissues except testis. Most of these CTA are highly immunogenic, eliciting a humoral and cellular response in the patients with advanced cancer, and are useful for tumor-specific immunotherapy. Medullary thyroid carcinoma (MTC) is a neoplasm derived from the parafollicular cells of the thyroid and occurs in either a sporadic or a familial form. In the present study, we examined by RT-PCR the expression of a number of genes encoding CTA in 23 surgical samples of sporadic MTC. Among the 11 cDNA antigens examined, RAGE, MAGE-4, and GAGE 1-2, were not expressed in any of the tissues. SSX 2 was present only in one tissue, whereas BAGE, GAGE 1-6, MAGE-1, MAGE-2, MAGE-3, and SSX 1-5 were detected in two to five samples. NY-ESO-1 cDNA was the most frequent, being detected in 15 of 23 examined samples (65.2%). Six (26.1%) tissues did not express any CTA-specific mRNA, whereas 10 tumors expressed only one gene (43.5%), 3 (21.4%) expressed 2 genes, and 4 displayed a broad CTA gene expression. NY-ESO-1 expression in primary MTC tissues significantly correlated with tumor recurrence. The presence of specific anti-NY-ESO-1 antibodies was searched in the sera of MTC-affected patients examined by ELISA using recombinant NY-ESO-1 protein. A humoral response against this CTA was detected in 6 of 11 NY-ESO-1 expressing patients (54.5%), and in 1 of 6 patients with NY-ESO-1-negative tumor. No anti-NY-ESO-1 antibodies were detected in healthy subjects (n = 17). The presence of anti-NY-ESO-1 antibodies was searched also in the sera of MTC affected patients whose tissues were not available for CTA analysis. Anti-NY-ESO-1 antibodies were present in 15 of 42 sera (35.7%), demonstrating that MTC is a neoplasm frequently associated with humoral immune response to NY-ESO-1. Serological survey may be useful as a way to identify patients with humoral immune response to NY-ESO-1 that provide a new attractive target for vaccine-based immunotherapy of MTC. PMID: 12574209 [PubMed - indexed for MEDLINE] PR75: Am J Surg Pathol. 2003 Feb;27(2):266-7. Comment on: Am J Surg Pathol. 2001 Oct;25(10):1245-51. Difference between familial and sporadic medullary thyroid carcinomas. Mears L, Diaz-Cano SJ. Publication Types: Comment Letter PMID: 12548176 [PubMed - indexed for MEDLINE] DR76: Am J Surg Pathol. 2003 Feb;27(2):159-66. Microscopic papillary thyroid carcinoma compared with clinical carcinomas by loss of heterozygosity mutational profile. Hunt JL, LiVolsi VA, Baloch ZW, Barnes EL, Swalsky PA, Niehouse L, Finkelstein SD. Department of Pathology, University of Pittsburgh Medical Center, Pennsylvania, USA. HUNTJL@msx.upmc.edu The clinical significance of microscopic papillary thyroid carcinoma (PTCa) is controversial. Many authors think that microscopic PTCa (<1 cm) have the same pathogenetic origin as clinically sized papillary carcinomas (>1 cm). Despite the fact that all clinical risk prognostication schemes have the size of the tumor as a primary category, small tumors do have malignant potential and can metastasize. There is growing evidence that small PTCa have the molecular translocations between the proto-oncogene RET and various activating partner genes that are characteristic of clinically sized PTCa. This study used a microdissection and genotyping assay to study the patterns of loss of heterozygosity of tumor suppressor genes in microscopic and clinically sized PTCa. Our results indicate that all PTCa harbor mutations with similar frequencies and distribution patterns, regardless of the size of the tumor. These data are further evidence that microscopic and clinically sized PTCa are pathogenetically related. PMID: 12548161 [PubMed - indexed for MEDLINE] DR77: ANZ J Surg. 2003 Jan-Feb;73(1-2):31-5. Temporal trends and clinical correlates for the ret/PTC1 mutation in papillary thyroid carcinoma. Burgess JR, Skabo S, McArdle K, Tucker P. Department of Diabetes and Endocrine Services, Royal Hobart Hospital, GPO Box 1061L, Hobart, Tasmania 7001, Australia. jburges@utas.edu.au BACKGROUND: The incidence of papillary thyroid carcinoma (PTC) has increased in Australia at a rate exceeding 10% per annum over the past two decades. In Tasmania the increase has averaged 24% per year between 1982 and 1997. Exposure to ionizing radiation is the best characterized risk factor for PTC. Oncogenic mutations of the RET proto-oncogene (ret/PTC rearrangements) have been associated with PTC arising following radiation exposure. In the present study it was sought to determine if PTC incidence trends were associated with an increased occurrence of the ret/PTC1 rearrangement. METHODS: All cases of PTC diagnosed in Tasmania during the even numbered years 1978-1998 inclusive were sought for study (n = 98). Archival histopathology blocks for 62 cases were located. The RNA was successfully extracted from 41 tumours and ret/PTC1 status assessed by reverse transcription-polymerase chain reaction. RESULTS: The ret/PTC1 mutation was found in 26 (63%) of PTC. The mean age at diagnosis for ret/PTC1-positive and ret/PTC1-negative tumours was 46.5 +/- 15.46 and 41.9 +/- 13.45 years, respectively. The ret/PTC1 positivity was significantly associated with larger tumour size. However, ret/PTC1 was not associated with an adverse prognosis. The prevalence of tumours positive for ret/PTC1 remained stable over the study period (1978-1998) and did not exhibit birth year or diagnosis year clustering. CONCLUSION: This is the first study to map temporal trends for the prevalence of ret/PTC1 relative to incidence trends for PTC. Although the ret/PTC1 mutation was frequently identified in Tasmanian PTC, there was no clear relationship between ret/PTC1 and recent PTC incidence trends. PMID: 12534735 [PubMed - indexed for MEDLINE] DR78: Oncogene. 2003 Jan 16;22(2):246-55. Ras-mediated apoptosis of PC CL 3 rat thyroid cells induced by RET/PTC oncogenes. Castellone MD, Cirafici AM, De Vita G, De Falco V, Malorni L, Tallini G, Fagin JA, Fusco A, Melillo RM, Santoro M. Istituto di Endocrinologia ed Oncologia Sperimentale del CNR, c/o Dipartimento di Biologia, University Federico II, Naples, Italy. RET gene rearrangements, which generate chimeric RET/PTC oncogenes, are early events in the evolution of thyroid papillary carcinomas. Expression of RET/PTC oncogenes promotes neoplastic transformation of cultured thyroid cells and of thyroid glands in transgenic mice. Notwithstanding these oncogenic effects, we have found that the expression of two RET/PTC oncogenes (H4-RET and RFG-RET) induces apoptosis of rat thyroid PC CL 3 cells. Promotion of thyroid cell death depends on the kinase activity of RET/PTC and on the phosphorylation of a tyrosine residue (tyrosine 1062) that maps in the carboxy-terminus of the RET protein. Tyrosine 1062 is essential for RET/PTC-mediated activation of the Ras/ERK pathway. Inhibition of Ras/ERK by a dominant negative Ras or by the MEKI inhibitor, PD98059, obstructed RET/PTC-mediated apoptosis. We also show that signals transmitted by tyrosine 1062 mediate proapoptotic events like Bcl-2 down regulation and Bax upregulation, and that adoptive overexpression of Bcl-2 overcomes RET/PTC-induced apoptosis. Thus, gene rearrangements that generate RET/PTC oncogenes subvert RET function by converting it into a chronically active kinase that is constitutively phosphorylated on tyrosine 1062. In turn, Y1062 phosphorylation transmits not only mitogenic but also proapoptotic signals to thyroid cells. PMID: 12527893 [PubMed - indexed for MEDLINE] DR79: J Clin Endocrinol Metab. 2003 Jan;88(1):459-63. Amplification and overexpression of mutant RET in multiple endocrine neoplasia type 2-associated medullary thyroid carcinoma. Huang SC, Torres-Cruz J, Pack SD, Koch CA, Vortmeyer AO, Mannan P, Lubensky IA, Gagel RF, Zhuang Z. Molecular Pathogenesis Unit, Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892, USA. We have previously identified two second hit mechanisms involved in the development of multiple endocrine neoplasia type 2 (MEN 2)-associated tumors: trisomy 10 with duplication of the mutant RET allele and loss of the wild-type RET allele. However, some of the MEN 2-associated tumors investigated did not demonstrate either mechanism. Here, we studied the TT cell line derived from MEN 2-associated medullary thyroid carcinoma with a RET germline mutation in codon 634, for alternative mechanisms of tumorigenesis. Although we observed a 2:1 ratio between mutant and wild-type RET at the genomic DNA level in this cell line, fluorescence in situ hybridization analysis revealed neither trisomy 10 nor loss of the normal chromosome 10. Instead, a tandem duplication event was responsible for amplification of mutant RET. In further studies we could for the first time demonstrate that the genomic chromosome 10 abnormalities in this cell line cause an increased production of mutant RET mRNA. These findings provide evidence for a third second hit mechanism resulting in overrepresentation and overexpression of mutant RET in MEN 2-associated tumors. PMID: 12519890 [PubMed - indexed for MEDLINE] DR80: Gan To Kagaku Ryoho. 2002 Dec;29(13):2451-7. [Genomic alterations in preneoplastic lesions] [Article in Japanese] Gemma A. 4th Department of Internal Medicine, Nippon Medical School, 1-1-5 Sendagi, Bunkyo-ku, Tokyo 113-8602, Japan. The genomic alterations in preneoplastic lesions are summarized in this review. 3p and 9p in the lung, 9p in the bladder, 8p in the prostata, 19q and 1p in oligodendroglioma, and 22q in meningioma were reported to be deleted. Somatic mutation of p53 was found in preneoplastic lesions of the esophagus, stomach, colon, thyroid, and astrocytoma. Adenoma-carcinoma sequence (Apc, ras, p53 gene alterations) in colon, LKB1 gene in Peutz-Jeghers syndrome, Smad4 in juvenile polyposis, hMSH2, hMLH1, PMS1, PMS2 genes in HNPCC, VHL gene in kidney, WT1 in Wilms tumor, RB gene in retinoblastoma, and ret gene in MEN were reportedly altered in preneoplastic lesions involved in hereditary tumors. Cervical dysplasia and papilloma of the head and neck infected by human papilloma virus and liver infected by B-type hepatitis virus are also precancerous. Genomic instability, APC gene alteration, point mutation of K-ras in preneoplastic lesions of stomach and K-ras and p16 alterations in metaplasia of pancreas were also found. Advances in research on genomic alterations in preneoplastic lesions will contribute to prevention and early detection of cancer. Publication Types: Review Review, Tutorial PMID: 12506466 [PubMed - indexed for MEDLINE] DR81: Cancer Res. 2002 Dec 15;62(24):7284-90. ZD6474, an orally available inhibitor of KDR tyrosine kinase activity, efficiently blocks oncogenic RET kinases. Carlomagno F, Vitagliano D, Guida T, Ciardiello F, Tortora G, Vecchio G, Ryan AJ, Fontanini G, Fusco A, Santoro M. Istituto di Endocrinologia ed Oncologia Sperimentale del Consiglio Nazionale delle Ricerche, Dipartimento di Biologia e Patologia Cellulare e Molecolare Luigi Califano, University Federico II, Naples, Italy. RET/papillary thyroid carcinoma (PTC) oncogenes, generated by recombination of the tyrosine kinase-encoding domain of RET with different heterologous genes, are prevalent in papillary carcinomas of the thyroid. Point mutations of RET cause multiple endocrine neoplasia type 2 (MEN2) familial cancer syndrome and are found in sporadic medullary thyroid carcinomas. Here, we show that ZD6474, a low molecular weight tyrosine kinase inhibitor, blocks the enzymatic activity of RET-derived oncoproteins at a one-half maximal inhibitory concentration of 100 nM. ZD6474 blocked in vivo phosphorylation and signaling of the RET/PTC3 and RET/MEN2B oncoproteins and of an epidermal growth factor (EGF)-activated EGF-receptor/RET chimeric receptor. RET/PTC3-transformed cells-treated ZD6474 lost proliferative autonomy and showed morphological reversion. ZD6474 prevented the growth of two human PTC cell lines that carry spontaneous RET/PTC1 rearrangements. Finally, it blocked anchorage-independent growth of RET/PTC3-transformed NIH3T3 fibroblasts and the formation of tumors after injection of NIH-RET/PTC3 cells into nude mice. Thus, targeting RET oncogenes with ZD6474 might offer a potential treatment strategy for carcinomas sustaining oncogenic activation of RET. PMID: 12499271 [PubMed - indexed for MEDLINE] DR82: Surgery. 2002 Dec;132(6):991-7; discussion 997. A new therapeutic approach in medullary thyroid cancer treatment: inhibition of oncogenic RET signaling by adenoviral vector-mediated expression of a dominant-negative RET mutant. Drosten M, Frilling A, Stiewe T, Putzer BM. Center for Cancer Research and Cancer Therapy, Institute of Molecular Biology, University of Essen Medical School, Hufelandstrasse 55, 45122 Essen, Germany. BACKGROUND: Mutations in the RET proto-oncogene that result in constitutive tyrosine kinase activity are the underlying cause for the development of medullary thyroid cancer (MTC). To investigate an alternative strategy in MTC treatment, we took advantage of a dominant-negative RET (dn-RET) mutant, Ret(51)HSCR32, which inhibits oncogenic signal transduction by retaining the oncogenic RET protein in the endoplasmic reticulum, thereby reducing the amount of oncogenic RET protein from the cell surface. METHODS; We constructed an adenoviral (Ad) vector expressing dn-RET under control of the C-cell specific synthetic calcitonin promoter TSE2.CP1 (AdTSE2.CP1-RET(51)HSCR32) and investigated the effect of dn-RET on cell growth of MTC-derived TT cells. RESULTS: Analysis of the subcellular localization of endogenous oncogenic RET protein showed a significant dominant-negative effect of Ad vector-delivered dn-RET in TT cells, resulting in a strong inhibition of cell viability. The observed effect is partially dependent on growth inhibition and possibly apoptosis induction. CONCLUSIONS: In the present study, growth of human MTC cells was successfully inhibited by Ad vector-mediated delivery of RET(51)HSCR32, suggesting that inhibition of oncogenic RET receptor tyrosine kinase expression by a dn-RET mutant might be a powerful approach for in vivo therapy of MTC. PMID: 12490846 [PubMed - indexed for MEDLINE] DR83: Surgery. 2002 Dec;132(6):960-6; discussion 966-7. Comment in: Surgery. 2004 Feb;135(2):240-1; author reply 241. Inhibition of medullary thyroid carcinoma cell proliferation and RET phosphorylation by tyrosine kinase inhibitors. Cohen MS, Hussain HB, Moley JF. Section of Endocrine and Oncologic Surgery, Washington University School of Medicine, St Louis, MO 63110, USA. BACKGROUND: Most medullary thyroid carcinomas (MTCs) result from gain-of-function mutations in the RET proto-oncogene, which encodes a transmembrane tyrosine kinase receptor. Systemic therapies have not been effective in treating this disease. We evaluated the effects of 3 tyrosine kinase inhibitors (TKIs) on MTC cell growth and RET tyrosine kinase activity by using an in vitro model. METHODS: An MTC cell line (TT cells, RETc634 mutant) cultured in RPMI medium was exposed to varying concentrations of STI571, genistein, or allyl-geldanamycin with controls (no TKI) for 3 to 48 hours. Cellular protein was analyzed by immunoprecipitated Western blot analysis probing with a monoclonal antiphosphotyrosine antibody. Cell proliferation was determined by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) and 5-bromo-2'-deoxyuridine (BrdU) assays. RESULTS: RET phosphorylation was inhibited at 24 hours of exposure to 5 to 20 micromol/L STI571 and 48 hours of exposure to genistein (200 micromol/L) and allyl-geldanamycin (6 micromol/L). RET protein was detected in equal concentrations in all experimental conditions. MTT and BrdU assays demonstrated a dose-dependent decrease in TT cell proliferation with exposure to the 3 TKIs. CONCLUSIONS: These TKIs selectively inhibit cell growth and RET tyrosine kinase activity of MTC cells in vitro in a dose manner. This study suggests the use of TKIs in human trials as a systemic therapy for MTC. PMID: 12490842 [PubMed - indexed for MEDLINE] NR84: Surgery. 2002 Dec;132(6):952-9; discussion 959. RET proto-oncogene mutations affecting codon 790/791: A mild form of multiple endocrine neoplasia type 2A syndrome? Gimm O, Niederle BE, Weber T, Bockhorn M, Ukkat J, Brauckhoff M, Thanh PN, Frilling A, Klar E, Niederle B, Dralle H. Department of General, Visceral, and Vascular Surgery, Martin-Luther-University Halle-Wittenberg, Ernst-Grube-Strasse 40, 06097 Halle, Germany. BACKGROUND: In patients with multiple endocrine neoplasia type 2A syndrome, prophylactic thyroidectomy is generally recommended at the age of 5 to 6 years. Whether this recommendation is justified for exon 13 mutations is unknown. METHODS: We analyzed the clinical data from 40 patients harboring RET codon 790/791 mutations (exon 13) who had been treated in 4 specialized centers. RESULTS: Mean age was 35.2 +/- 21.6 years (range, 5.1-69.0 years). Thirteen patients were index patients (mean age, 57.7 +/- 11.3 years), 27 patients were screening patients (mean age, 24.4 +/- 16.5 years). In the index group, pT-category was: T0, n = 2; T1, n = 6; T2, n = 2; T3, n = 1; and T4, n = 2. Lymph node metastases were found in 5 patients and distant metastases in 1 patient. Postoperatively, 69% of index patients were biochemically cured. In the screening group, pT-category was: T0, n = 19; T1, n = 7; and T2, n = 1. Lymph node metastases were found in 2 patients. Postoperatively, 93% of screening patients were biochemically cured. The youngest patient with medullary thyroid carcinoma was 13.8 years, the youngest patient with lymph node metastases was 46.4 years. CONCLUSIONS: Patients with RET codon 790/791 mutations seemed to have a less aggressive clinical course compared with patients with classic multiple endocrine neoplasia type 2A syndrome. Still, index patients had a lower biochemic cure rate in comparison with screening patients. Timely total thyroidectomy including lymph node dissection is warranted. Publication Types: Multicenter Study PMID: 12490841 [PubMed - indexed for MEDLINE] DR85: Thyroid. 2002 Nov;12(11):1017-22. Evaluation of germline sequence variants of GFRA1, GFRA2, and GFRA3 genes in a cohort of Spanish patients with sporadic medullary thyroid cancer. Borrego S, Fernandez RM, Dziema H, Japon MA, Marcos I, Eng C, Antinolo G. Unidad de Genetica Medica y Diagnostico Prenatal, Hospitales Universitarios Virgen del Rocio, Sevilla, Spain. The etiology of sporadic medullary thyroid carcinoma (sMTC) remains elusive. While germline gain-of-function mutations in the RET proto-oncogene cause hereditary MTC, somatic RET mutations have been described in a variable number of sMTC. So far, S836S of RET, is the only variant whose association with sMTC has been found in several European cohorts. Because RET variants seem to be associated with MTC, it is plausible that variants in genes encoding for RET coreceptors may play a role in the pathogenesis of sMTC. Recently, we described two possible low penetrance susceptibility alleles in the gene encoding RET coreceptor GFRalpha1, -193C > G and 537T > C, in a German series of sMTC. In this study, we have genotyped nine polymorphisms within GFRA1-3 genes for 51 Spanish sMTC, and 100 normal controls. Our results show that no statistical signification was found when Spanish sMTC patients were compared to controls. Taken together with the observations in the German sMTC series, the present findings suggest that GFRA1-193C > G and 537T > C could be in linkage disequilibrium with other loci responsible for the disease with a founder effect in Germany. Alternatively, the combined observations might also suggest that, if indeed the polymorphisms are functional, the effect is small. PMID: 12490080 [PubMed - indexed for MEDLINE] DR86: Am J Hum Genet. 2003 Jan;72(1):88-100. Epub 2002 Dec 9. A founding locus within the RET proto-oncogene may account for a large proportion of apparently sporadic Hirschsprung disease and a subset of cases of sporadic medullary thyroid carcinoma. Borrego S, Wright FA, Fernandez RM, Williams N, Lopez-Alonso M, Davuluri R, Antinolo G, Eng C. Unidad de Genetica Medica y Diagnostico Prenatal, Hospitales Universitarios Virgen del Rocio, Sevilla, Spain. gantinolo@hvr.sas.cica.es Hirschsprung disease (HSCR) is a common congenital disorder characterized by aganglionosis of the gut. The seemingly unrelated multiple endocrine neoplasia type 2 (MEN 2) is an autosomal dominant disorder characterized by medullary thyroid carcinoma (MTC), pheochromocytoma, and hyperparathyroidism. Yet, germline mutations in the RET proto-oncogene are associated with both MEN 2 and HSCR. In the former, gain-of-function mutations in a limited set of codons is found, whereas, in the latter, loss-of-function mutations are found. However, germline RET mutation is associated with only 3% of a population-based series of isolated HSCR, and little is known about susceptibility to sporadic MTC. We have found previously that specific haplotypes comprising RET coding single-nucleotide polymorphisms (SNPs) comprising exon 2 SNP A45A were strongly associated with HSCR, whereas haplotypes associated with exon 14 SNP S836S were associated with MTC. In this study, we describe three novel intron 1 SNPs, and, together with the coding SNP haplotypes, the data suggest the presence of distinct ancestral haplotypes for HSCR and sporadic MTC in linkage disequilibrium with a putative founding susceptibility locus/loci. The data are consistent with the presence of a very ancient, low-penetrance founder locus approximately 20-30 kb upstream of SNP A45A, but the failure of the SNPs to span the locus presents challenges in modeling mode of transmission or ancestry. We postulate that this founding locus is germane to both isolated HSCR and MTC but also that different mutations in this locus would predispose to one or the other. PMID: 12474140 [PubMed - indexed for MEDLINE] DR87: Pediatr Surg Int. 2002 Sep;18(5-6):378-83. Epub 2002 Apr 11. Diagnostic and therapeutic approach to multiple endocrine neoplasia type 2B in pediatric patients. Torre M, Martucciello G, Ceccherini I, Lerone M, Aicardi M, Gambini C, Jasonni V. Divisione e Cattedra di Chirurgia Pediatrica, Istituto G. Gaslini, Largo G. Gaslini, Genoa, Italy. micheletorre@hotmail.com Multiple endocrine neoplasia (MEN) 2B is a hereditary syndrome including medullary thyroid carcinoma (MTC), pheochromocytoma, gastrointestinal (GI) disorders, marfanoid facies, and multiple ganglioneuromas. MTC is the major cause of mortality, and often appears during the 1st decade of life. RET proto-oncogene mutations are responsible for MEN 2B. Other RET mutations cause MEN 2A syndrome, familial MTC, or Hirschsprung's disease. We studied three MEN 2B patients with the aim of delineating the best diagnostic and therapeutic protocol. The gold standards for diagnosis are histochemical study of the rectal mucosa and molecular analysis of RET, which in familial cases detects MEN 2B at a preclinical stage so that early total prophylactic thyroidectomy can be performed. In non-familial cases, the diagnosis can be suggested by the presence of GI symptoms, ganglioneuromas, and/or the typical facies. The intestinal innervation pattern, analyzed with the acetylcholinesterase technique, is pathognomonic for MEN 2B. In our protocol a rectal biopsy is, therefore, the first measure. The surgical treatment of MEN 2B is total thyroidectomy with cervical lymphadenectomy of the central compartment of the neck. When possible, this intervention should be performed prophylactically before 1 year of age. Publication Types: Case Reports PMID: 12415360 [PubMed - indexed for MEDLINE] DR88: Langenbecks Arch Surg. 2002 Oct;387(5-6):201-3. Epub 2002 Sep 27. Primary hyperparathyroidism, C-cell hyperplasia and papillary thyroid carcinoma in a patient with RET germline polymorphism S836S. Brauckhoff M, Gimm O, Bilkenroth U, Hinze R, Dralle H. Department for General, Visceral, and Vascular Surgery, Martin Luther University Halle/Wittenberg, Ernst-Grube-Strasse 40, 06097 Halle/Saale, Germany. michael.brauckhoff@medizin.uni-halle.de BACKGROUND: In most examined populations the RET germline polymorphism S836S is found in about 3.6% of the normal population but in about 9% of patients suffering from sporadic C-cell hyperplasia or medullary thyroid carcinoma. The polymorphism S836S is thought to be involved in the development of sporadic medullary thyroid carcinoma. CASE PRESENTATION: We report a 48-year-old woman suffering from primary hyperparathyroidism (parathormone 121-166 pg/ml, normal <72), bilateral diffuse and nodular C-cell hyperplasia (calcitonin after pentagastrin administration 156 pg/ml, normal <4.6), and papillary thyroid carcinoma. Two commercial analyses of RET did not reveal any germline mutation within the known hot spots. However, sequencing revealed the presence of the RET polymorphism S836S. Following total thyroidectomy and removal of two hyperplastic parathyroid glands parathormone decreased to 51 pg/ml and calcitonin was no longer detected. CONCLUSIONS: The pathogenetic importance of the RET polymorphism S836S is still obscure. However, according to the published overrepresentation of the RET polymorphism S836S in patients suffering from apparent sporadic medullary thyroid carcinoma, it is conceivable that it also plays a role in multiglandular endocrine disease. Publication Types: Case Reports PMID: 12410354 [PubMed - indexed for MEDLINE] NR89: Ann Surg. 2002 Nov;236(5):570-5. Various penetrance of familial medullary thyroid carcinoma in patients with RET protooncogene codon 790/791 germline mutations. Fitze G, Schierz M, Bredow J, Saeger HD, Roesner D, Schackert HK. Departments of Pediatric Surgery, General Surgery, Nuclear Medicine, and Surgical Research, University of Technology Dresden, Dresden, Germany. guido.fitze@mailbox.tu-dresden.de OBJECTIVE: To describe a genotype-phenotype correlation in MEN2 families with germline mutations of codons 790/791 and discuss options for the therapeutic management of gene carriers. SUMMARY BACKGROUND DATA: Heredity of MEN2 syndromes is caused by a heterozygous germline mutation in the protooncogene. Rare mutations of codons 790/791 associated with incomplete penetrant MEN2A/FMTC phenotype were reported in five families, contraindicating the prophylactic thyroidectomy for the genetically affected children. METHODS: Forty-five patients with a putative sporadic MTC were screened for germline mutations by direct DNA sequencing. Family members of identified index cases underwent genetic analysis. Gene carriers were examined clinically and biochemically, and all gene carriers underwent prophylactic thyroidectomy. RESULTS: Five index patients were identified, four of whom harbored mutations in codons 790/791 and one in codon 634. In the kindreds, four L790F carriers and one Y791F carrier were detected. The thyroid gland histology of L790F carriers revealed medullary thyroid carcinoma in two patients (aged 29 and 50 years) and C-cell hyperplasia in two additional patients (aged 9 and 16 years). The Y791F carrier had a normal histology. CONCLUSIONS: Codon 790/791 mutations had diverse penetrance. Whereas prophylactic thyroidectomy in children is a justifiable approach for codon 790 mutation carriers, the indication for thyroidectomy should depend on the clinical course of codon 791 carriers. PMID: 12409662 [PubMed - indexed for MEDLINE] DR90: Ann N Y Acad Sci. 2002 Sep;970:11-28. New insights into the genetics of familial chromaffin cell tumors. Koch CA, Vortmeyer AO, Zhuang Z, Brouwers FM, Pacak K. Pediatric and Reproductive Endocrinology Branch, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA. kochk@exchange.nih.gov We review genetic aspects and recent advances in our understanding of the molecular pathogenesis of familial chromaffin cell tumors (pheochromocytoma, paraganglioma). About 10 percent of pheochromocytomas are familial and occur as part of multiple endocrine neoplasia type 2 (MEN 2), von Hippel-Lindau (VHL) disease, and neurofibromatosis type 1 (NF 1). A subset of paragangliomas, tumors that can also produce and secrete catecholamines, are also familial and occur in patients with germline mutations in genes that encode subunits of the mitochondrial complex II. The precise molecular mechanisms underlying the pathogenesis of chromaffin cell tumors remain widely unknown, although recent studies in hereditary tumors help elucidate their development. In MEN 2, overrepresentation of mutant RET in selected adrenomedullary cells may be an important mechanism in initiating the formation of a pheochromocytoma. In VHL disease, pheochromocytoma development appears to occur according to Knudson's two-hit model, a VHL germline mutation and wildtype allelic deletion. Tumorigenesis of NF1-associated pheochromocytomas remains unknown, as does tumor formation (i.e., carotid body tumor) in patients with germline mutations in SDHB, SDHC, and SDHD, genes that encode subunits of the mitochondrial complex II, the smallest complex in the respiratory chain. Many genetic alterations have been found in sporadic chromaffin cell tumors. However, at present such genetic changes are difficult to place into context with regard to tumor formation and progression. Publication Types: Review Review, Tutorial PMID: 12381538 [PubMed - indexed for MEDLINE] DR91: Presse Med. 2002 Aug 10;31(26):1224-30. [Polyadenomatoses: type 2 multiple endocrine neoplasms] [Article in French] Conte-Devolx B, Niccoli-Sire P; Groupe d'Etude des Tumeurs a Calcitonine. Service d'Endocrinologie-Maladies Metaboliques, Hopital de la Timone 13385 Marseille. bconte-devolx@aphm.fr FROM A CLINICAL POINT OF VIEW: Multiple endocrine neoplasia type 2 (MEN2) is an autosomal dominant, inherited multiglandular disease with familial and individual age-related penetration and variable expression. A medullary thyroid carcinoma (MTC) is always concomitant to MEN2 and associated in varying proportion with pheochromocytoma (50%) and hyperparathyroidism (5 to 20%). PROGNOSTIC DATA: The prognosis of MEN2 is related to the carcinological evolution of MTC, which depends mainly on the stage of discovery and the quality of the first surgical treatment, emphasizing the need for early diagnosis. THE IMPORTANCE OF THE ERT GENE: The identification of mutations in proto-oncogene RET, responsible for the various forms of the disease allows subjects at risk in a family circle to be identified and early screening of various endocrine damage, notably MTC, should be performed. Biological explorations in all persons carrying this mutation would permit diagnosis and surgical treatment of the endocrine lesions, before their clinical manifestation. PMID: 12212516 [PubMed - indexed for MEDLINE] DR92: World J Surg. 2002 Oct;26(10):1286-90. Epub 2002 Sep 4. Surgical strategy in a kindred with a rare RET protooncogene mutation of variable penetrance with regard to multiple endocrine neoplasia. Colombo-Benkmann M, Bramswig J, Hoppner W, Gellner R, Hengst K, Bocker W, Senninger N. Department of General Surgery, University of Munster, Waldeyerstrasse 1, 48149 Munster, Germany. m.colombo.benkmann@uni-muenster.de Prophylactic thyroidectomy is recommended for carriers of RET protooncogene mutations owing to their nearly complete penetrance for medullary thyroid carcinoma (MTC). However, this guideline is challenged by mutations exhibiting variable penetrance of C-cell pathology. A 38-year-old woman presented with pathologic basal and pentagastrin-stimulated calcitonin levels. Genetic analysis revealed a heterozygous RET protooncogene germline mutation in codon 791 (exon 13) (TAT(Tyr)-->TTT(Phe)), followed by thyroidectomy and systematic central lymph node dissection. Histology showed C-cell hyperplasia (CCH) only. Three additional carriers were identified among family members. The 71-year-old father refused surgery despite pathologic calcitonin levels. The index patient's 37-year-old sister had normal basal and stimulated calcitonin levels, and her 6-year-old son had a 10-fold rise of calcitonin after pentagastrin stimulation. Both patients underwent the same operation as the index patient. The sister had 25 hyperplastic C-cells, but the her son had extensive CCH without MTC. The eldest uncle of the index patient had died of metastatic MTC at the age of 52 with unknown carrier status. Despite variable penetrance, each carrier of a RET protooncogene germline mutation should undergo thyroidectomy, even if basal and stimulated calcitonin levels are normal because at present no test can exclude or predict the age of development of MTC. Moreover, pathologic calcitonin levels cannot differentiate between CCH and MTC. Central lymph node dissection is recommended, as lymph node metastases occur early, significantly worsening the prognosis. Publication Types: Case Reports PMID: 12205548 [PubMed - indexed for MEDLINE] DR93: Clin Chem. 2002 Sep;48(9):1505-10. Comparison of two provocative tests for calcitonin in medullary thyroid carcinoma: omeprazole vs pentagastrin. Vitale G, Ciccarelli A, Caraglia M, Galderisi M, Rossi R, Del Prete S, Abbruzzese A, Lupoli G. Dipartimento di Endocrinologia ed Oncologia Molecolare e Clinica, Universita degli Studi di Napoli Federico II, Via E. Nicolardi 145, P. co Arcadia 8, 80131 Naples, Italy. BACKGROUND: Provocative tests for calcitonin (CT) are fundamental in the diagnosis and follow-up of C-cell disease and in the detection of hereditary medullary thyroid carcinoma (MTC) carriers with unknown RET mutations. A recent report has proposed omeprazole, which can increase endogenous gastrin (GT), as a new provocative test for MTC. METHODS: We compared the omeprazole test (20 mg twice a day for 4 days) to the pentagastrin test (0.5 microg/kg of body weight) for the diagnosis and management of MTC. Twenty healthy individuals and 20 MTC patients with mildly or moderately increased basal CT serum concentrations underwent the pentagastrin and omeprazole tests. RESULTS: In MTC patients, the pentagastrin test produced a significantly higher increase in serum CT than did omeprazole. After the pentagastrin injection, several patients reported unpleasant side effects, including substantial tightness in 38 of 40 participants. No adverse effects were observed during the omeprazole test. A significant direct correlation was recorded between CT% (ratio of CT peak to basal value x 100) and GT% (ratio of GT peak to basal value x 100) during the omeprazole test in MTC patients (r = 0.73; P <0.001). CONCLUSIONS: In spite of several adverse effects, pentagastrin remains the best provocative test for the diagnosis of MTC. Omeprazole may be useful when pentagastrin is contraindicated or refused because of the unpleasant side effects, but further validation is needed. Publication Types: Clinical Trial Controlled Clinical Trial PMID: 12194927 [PubMed - indexed for MEDLINE] DR94: Thyroid. 2002 Jul;12(7):557-61. Papillary thyroid carcinoma in patients with RET proto-oncogene germline mutation. Brauckhoff M, Gimm O, Hinze R, Ukkat J, Brauckhoff K, Dralle H. Department of General, Visceral and Vascular Surgery, Martin-Luther-University Halle-Wittenberg, Halle, Germany. michael.brauckhoff@medizin.uni-halle.de The occurrence of papillary thyroid carcinoma in patients with RET germline mutations has been described in only eight cases since 1993. We report three women with a RET germline mutation in exon 13 and 14, affecting codon 790, 791, and 804, respectively, who underwent prophylactic thyroidectomy at the age of 29, 39, and 24 years, respectively. Histologic examination revealed C-cell hyperplasia and a small medullary thyroid carcinoma in the first patient and no pathologic changes of the C-cells in either of the other patients. However, all patients had papillary thyroid carcinoma (PTC). Concerning the frequency of PTC in patients with RET germline mutations who underwent surgery at our center (n = 104), it was found in 9.1% of all patients with RET mutation in codon 790, 791, and 804 (n = 33) but in none of the 104 patients with RET germline mutations not affecting codon 790, 791, or 804 (p = 0.0015). Our data and the data from the literature suggest a possible pathogenesis of PTC caused by exon 13 and 14 RET mutations that affect the intracellular domain of the encoded protein. Further investigation is necessary to confirm a potential pathogenetic role of exon 13 and 14 RET mutations with regard to the development of PTC. Publication Types: Case Reports PMID: 12193298 [PubMed - indexed for MEDLINE] DR95: Wiad Lek. 2001;54 Suppl 1:415-21. [Proto-oncogene RET somatic mutations in medullary thyroid carcinoma] [Article in Polish] Wiench M, Kwasniewski M, Gubala E, Wygoda Z, Pawlaczek A, Oczko M, Jarzab B. Zakladu Medycyny Nuklearnej i Endokrynologii Onkologicznej, Centrum Onkologii-Instytut im. M. Sklodowskiej-Curie, Oddzial w Gliwicach. Somatic mutations of the RET protooncogene are present in 23-68% cases of sporadic medullary thyroid carcinoma (MTC). The aim of the study was to introduce the RET somatic mutations analysis in tumor tissue as well as to evaluate their types and frequencies in postoperative specimens of MTC patients treated in the Center of Oncology in Gliwice. MATERIAL: 14 tumor tissues obtained from sporadic MTC patients and two control groups--six and four specimens from patients with MEN 2A and MEN 2B syndrome respectively. METHODS: Tumor tissue DNA isolation followed by PCR amplification of RET exons 10, 11, 13, 14, 16 and automated, fluorescent sequencing of PCR products. We identified somatic mutation ATG > ACG in codon 918, exon 16 in 7 of 14 (50%) of analyzed sporadic MTC cases. We also found one deletion/insertion mutation in RET exon 11 that encompasses cysteine codon 634 and has not been published so far. The types and frequencies of found RET gene mutations were similar to previously reported. The analysis of RET somatic mutations supports the differentiation between the sporadic and inherited MTC. The presence of somatic mutation and its simultaneous absence in the germline proves sporadic type of cancer. PMID: 12182058 [PubMed - indexed for MEDLINE] DR96: Wiad Lek. 2001;54 Suppl 1:406-14. [Consequences of clinical genetic analysis of RET proto-oncogene] [Article in Polish] Wloch J, Wygoda Z, Wiench M, Gubala E, Kula D, Oczko M, Lange D, Jarzab B. Kliniki Chirurgii Onkologicznej, Centrum Onkologii-Instytut im. M. Sklodowskiej-Curie, Oddzial w Gliwicach. Preliminary results of treatment of inherited medullary thyroid carcinoma, diagnosed primarily with genetic analysis of mutation of protooncogene RET are presented. Among 16 carriers of mutation identical with mutation diagnosed earlier in proband, there were 4 patients with clinically obvious medullary thyroid carcinoma and 12 asymptomatic carriers. In all patients, in whom calcitonin level was increased preoperatively, its normalization was obtained. The paper summarizes these aspects of cooperation between geneticians and physicians in which diagnostic results influence clinical decisions (indication and time of thyroid and lymph nodes surgery and it's spectrum, range of diagnostic procedures towards pheochromocytoma and parathyroid hyperplasia in relation to the found mutation). PMID: 12182057 [PubMed - indexed for MEDLINE] DR97: J Am Coll Surg. 2002 Aug;195(2):159-66. Prophylactic thyroidectomy in MEN 2A syndrome: experience in a single center. Rodriguez GJ, Balsalobre MD, Pomares F, Torregrosa NM, Rios A, Carbonell P, Glower G, Sola J, Tebar J, Parrilla P. Department of Surgery, Virgen de la Arrixaca Hospital, Murcia, Spain. BACKGROUND: Genetic study of the RET proto-oncogene has modified the management, treatment, and prognosis of medullary thyroid carcinoma (MTC), multiple endocrine neoplasia 2A (MEN 2A), for patients with less advanced tumor stages. Classically, the diagnosis was based on an increase in basal and poststimulus peak calcitonin (bCT and pCT). Prophylactic thyroidectomy, based on results of genetic testing, may reduce recurrences in MTC. STUDY DESIGN: Of 82 MTC (MEN 2A) patients genetically diagnosed and surgically treated at our center, 22 received a prophylactic thyroidectomy (RET +, bCT and pCT with normal values and asymptomatic). We analyzed age, gender, phenotype, RET mutation, cervical ultrasound, laboratory tests (bCT, pCT, and CEA), surgery, histologic data, TNM, and followup. RESULTS: The 22 patients belonged to 8 families with MTC (MEN 2A). Mean age was 15.2 years (range 5 to 36 years). The RET mutation in 21 patients was Cys-->Tyr and in the remaining patient both in codon 634 in exon 11. The median values of bCT and pCT were 38 pg/mL (range < 15 to 75 pg/mL) and 148.5 pg/mL (range < 15 to 250 pg/mL), respectively. Total thyroidectomy was performed in 8 patients (age < or = 10 years) and associated central neck dissection in 14 patients (age> 10 years). Histologic study showed 7 C-cell hyperplasias and 15 MTCs (8 bilateral); the median size was 0.2 cm (range < 0.1 to 0.7cm); 1 patient had metastatic adenopathies. According to TNM, 7 were stage 0, 14 were stage I, and 1 was stage III. Postsurgery bCT and pCT values were normal in all patients, with a curative rate of 100%. MTC patients compared with C-cell hyperplasia patients were older on average, had higher mean bCT, mean pCT, and mean CEA. CONCLUSIONS: Prophylactic thyroidectomy based on genetic testing allows identification and treatment of patients at an early stage of the disease and decreases recurrence rates. pCT values above the upper limit of normal may be markers for the presence of MTC and should be considered in selecting operative procedures for these patients. PMID: 12168961 [PubMed - indexed for MEDLINE] PR98: J Endocrinol Invest. 2002 Jul-Aug;25(7):603-8. Clinical characteristics and genetic screening of an extended family with MEN2A. Algun E, Abaci N, Kosem M, Kotan C, Koseoglu B, Boztepe H, Sekeroglu R, Aslan H, Topal C, Ayakta H, Uygan I, Alagol F, Erginel-Unaltuna N, Aksoy H. Yuzuncu Yil University, School of Medicine, Department of Endocrinology, Van, Turkey. ekremalgun@hotmail.com MEN-2A is characterized by medullary thyroid carcinoma (MTC) with pheochromocytoma and sometimes parathyroid adenoma. In affected members of the family, the risk of MTC is about 100%. Biochemical screening allows tumors to be detected early but even at this stage treatment is not always curative. Missense mutations in exon 10 and 11 of the RET proto-oncogene are associated with MEN-2A. Early detection of this mutation by DNA analysis allows the identification of the carriers of the gene. We performed genetic screening in 88 members of an extended family with MEN-2A and found 18 members positive for RET mutation (Cys634Gly). Only three of these 18 RET positive cases had a previous diagnosis of medullary cancer and/or pheochromocytoma. Up to now, 12 of the RET positive cases have undergone thyroidectomy. There was extended disease with cervical lymph node metastasis in 6 of them, bilateral medullary microcancer in 3 and c-cell hyperplasia in the remaining 3. Three of the 18 RET positive patients had also pheochromocytoma. Primary hyperparathyroidism was present in only one patient. The mean age of diagnosis of medullary cancer was between 25-50 yr and mean age of death was between 35-95 yr in affected members of the family. The family had many other affected members in other cities in Turkey and in other countries throughout the world from Australia to the Netherlands. So this family is perhaps one of the most extended families with MEN-2A. PMID: 12150334 [PubMed - indexed for MEDLINE] NR99: Bull Cancer. 2002 Jun;89(6):588-92. [From the cytogenetics to the cytogenomics of thyroid tumors] [Article in French] Perissel B, Bernheim A, Couturier J, Fouilhoux G, Vago P, Oncologique GF. Laboratoire de cytogenetique medicale, Faculte de medecine, BP 38, 63001 Clermont-Ferrand Cedex, France. Benign and malignant thyroid tumors constitute a wide range of neoplasias showing recurrent chromosome abnormalities. Cytogenetic studies of thyroid hyperplasias and follicular adenomas revealed hyperdiplo d karyotypes with a characteristic sequence of trisomies (7, 5, 12, 14, 16, 17, 20 and 22) starting with trisomy 7. Comparative genomic hybridization (CGH) findings on thyroid oncocytic tumors showed similar chromosomal gains with no difference observed between adenomas and carcinomas. Follicular thyroid carcinomas exhibit losses of 3p25-pter predominantly or of 22,13 and 1p segments. Formation of fusion genes PAX8 - PPARgamma1 caused by a t(2;3)(q13;p25) has been observed in several cases of follicular carcinomas only. Loss of chromosome 22 has been found most frequently associated with widely invasive follicular carcinomas. Activation of the RET protooncogene through chromosome rearrangements involving subband 10q11.2 represent the most common and specific genetic alteration in papillary thyroid carcinoma. Several chimeric genes resulting in the fusion of the tyrosine kinase domain of RET with the 5' sequences of different genes have been described. Germline mutations in RET are associated with medullary thyroid carcinoma in multiple endocrine neoplasia type 2 (MEN2). Cytogenetics of thyroid tumors, using conventional and molecular methods (FISH, CGH) demonstrated that particular chromosome aberrations may be related to the clinical behavior of these tumors and may provide informations for their diagnosis or prognosis. Publication Types: Review Review, Tutorial PMID: 12135859 [PubMed - indexed for MEDLINE] DR100: Am J Med Genet. 2002 Jun 1;110(1):85-7. A novel germline point mutation, c.2304 G-->T, in codon 768 of the RET proto-oncogene in a patient with medullary thyroid carcinoma. Antinolo G, Marcos I, Fernandez RM, Romero M, Borrego S. Publication Types: Case Reports Letter PMID: 12116277 [PubMed - indexed for MEDLINE] DR101: Endocr Pathol. 1995 Winter;6(4):267-278. Molecular Diagnosis of Multiple Endocrine Neoplasia (MEN) in Paraffin-Embedded Specimens. Komminoth P, Muletta-Feurer S, Saremaslani P, Kunz EK, Matias-Guiu X, Hiort O, Schroder S, Seelentag WK, Roth J, Heitz PU. MD, PhD. In this article, we summarize our recent findings on rearranged during transfection (RE7) mutations in a series of 46 sporadic as well as multiple endocrine neoplasia (MEN) type 2- associated tumors and present results of our family screening efforts to identify MEN 2 and MEN 1 gene carriers. A nonisotopic polymerase chain reaction-based single-strand conformation polymorphism (PCR-SSCP) analysis and heteroduplex gel electrophoresis method was used to screen DNA extracted from archival specimens of 22 patients with MEN 2-associated and 24 patients with sporadic tumors for mutations in RETexons 1O, 11, 13, and 16. Point mutations were identified by nonisotopic cycle sequencing of PCR products using an automated DNA sequencer. We found six different missense germ line mutations at cysteine residues encoded by exons 10 and 11 in all patients with MEN 2A or familial medullary thyroid carcinoma (FMTC). The frequency of mutations at codon 634 was higher in patients with MEN 2A than with FMTC and a (63)Cys - Arg mutation was associated with parathyroid disease. A germline Met -* Thr point mutation at codon 918 of the RETtyrosine kinase domain encoded by exon 16 was identified in all MEN 2B patients. Nonpredicted inheritable medullary thyroid carcinomas (MTCs) were detected in two patients and a mosaic postzygotic mutation was found in one additional patient. Tumor-specific (somatic) Met - Thr point mutations at codon 918 were identified in 5 of 13 sporadic MTCs and 2 of 8 sporadic pheochromocytomas (PCCs). The remaining sporadic tumors lacked mutations in all four RET exons tested. In exon 13, a nucleic acid polymorphism (CTT/CTG; Leu) at codon 769 was identified, which is present in approx 40% of the examined population. Our study demonstrates that the molecular methods used are not only suitable to identify asymptomatic individuals at risk for MEN 2A, FMTC, and MEN 2B, but also to distinguish sporadic from inherited tumors using archival tissue specimens; and that more tumors than clinically expected are inheritable, indicating the need for genetic analysis of all MTC and PCC patients. PMID: 12114809 [PubMed - as supplied by publisher] DR102: Endocr Pathol. 1997 Autumn;8(3):235-239. RET Proto-Oncogene and Thyroid Cancer. Komminoth P. The RET proto-oncogene has not only conclusively been identified as responsible for the three subtypes of the inherited cancer syndrome multiple endocrine neoplasia type 2 (MEN-2) but also shown to be involved in the molecular evolution of sporadic medullary and papillary thyroid carcinoma as well as Hirschsprung's disease. A variety of recent studies have elucidated the pathophysiological mechanisms leading to neoplastic disease and we now understand that dominant activating germline mutations lead to MEN-2A, MEN-2B, and familial MTC; somatic mutations to sporadic medullary thyroid carcinoma; RET rearrangements to papillary thyroid carcinoma; and inactivating alterations to Hirschsprung's disease. The clinical significance, however, of RET alterations especially in sporadic thyroid tumors is still controversial and therapeutic concepts in MEN-2 gene carriers only start to emerge. This article is a short summary of the recent findings on the structure and physiology of the RET proto-oncogene and its role in familial and sporadic thyroid cancer. PMID: 12114728 [PubMed - as supplied by publisher] DR103: Endocr Pathol. 1996 Spring;7(1):71-76. Molecular Screening for RET Proto-Oncogene Mutations in a German MEN2A Pedigree. Wundrack I, Reichert J, Langer HJ, Leicht E, Herrmann M, Subke F, Meese E, Blin N. Multiple endocrine neoplasia type 2A (MEN2A), a dominantly inherited cancer syndrome, is defined by the presence of medullary thyroid carcinoma (MTC), pheochromocytoma (pheo), and primary hyperparathyroidism (p-HPT). Along with multiple endocrine neoplasia type 2B (MEN2B) and familial medullary thyroid carcinoma (FMTC), it is associated with germline mutations of the RETproto-oncogene localized in 10q11.2. In FMTC and MEN2A, point mutations result in the substitution of one of five Cys residues in the extracellular domain of RET. In a larger pedigree from Saarland, several individuals were observed with C-cell thyroid carcinoma. We screened 16 members of this extended family by single-strand conformation polymorphism analysis (SSCP), polymerase chain reaction (PCR), followed by restriction enzyme analysis, and by sequencing the mutated regions. In 7 family members, all of whom had been earlier operated on because of MTC, a DNA transition from T to C was observed, causing an amino acid substitution Cys(634)Arg. Nine members of the kindred did not carry the mutation and may be excluded from yearly biochemical testing. One of these persons seems to have been unnecessarily operated on owing to a borderline pentagastrin test. PMID: 12114682 [PubMed - as supplied by publisher] NR104: Endocr Pathol. 1998 Spring;9(1):79-90. Concurrent Pheochromocytoma, Paraganglioma, Papillary Thyroid Carcinoma, and Desmoid Tumor: A Case Report with Analyses at the Molecular Level. Scopsi L, Cozzaglio L, Collini P, Gullo M, Bongarzone I, Giarola M, Radice P, Gennari L. MD, DMSC. Reports on the association of papillary thyroid carcinoma with paraganglionic or desmoid tumors have appeared infrequently. The former setting usually affects middle-aged females; the latter is typical of familial adenomatous polyposis. We report the case of a 69-yr-old man in whom two abdominal masses had been instrumentally detected following an access of abdominal pain. Save for a moderate hypertension, he was asymptomatic and an impalpable thyroid nodule was detected by ultrasonography. A high urinary noradrenaline output and cytology of the masses raised the suspicion of pheochromocytoma. At laparotomy, an adrenal pheochromocytoma and a paracaval paraganglioma were excised. Subsequently, hemithyroidectomy was performed, and histopathology revealed papillary microcarcinoma. A nodule of desmoid tumor was also removed from the abdominal wall. An analysis of RET, APC, and TP53 gene mutations, and of RET and NTRK1 gene rearrangements, yielded negative results. No in vitro transforming activity was detected in the tumor DNA when assayed in transfection experiments. The lack of a consistent family history also made unlikely the possibility of identifying the putative germline defect by linkage analyses. Should this unusual aggregation of tumors represent a new entity, a number of genetic alterations have now been excluded. PMID: 12114665 [PubMed - as supplied by publisher] DR105: Am J Pathol. 2002 Jul;161(1):249-56. Characterization of gene expression induced by RET with MEN2A or MEN2B mutation. Watanabe T, Ichihara M, Hashimoto M, Shimono K, Shimoyama Y, Nagasaka T, Murakumo Y, Murakami H, Sugiura H, Iwata H, Ishiguro N, Takahashi M. Department of Pathology, Nagoya University Graduate School of Medicine, Nagoya, Japan. Germ-line point mutations of the RET gene are responsible for multiple endocrine neoplasia (MEN) type 2A and 2B that develop medullary thyroid carcinoma and pheochromocytoma. We performed a differential display analysis of gene expression using NIH 3T3 cells expressing the RET-MEN2A or RET-MEN2B mutant proteins. As a consequence, we identified 10 genes induced by both mutant proteins and eight genes repressed by them. The inducible genes include cyclin D1, cathepsins B and L, and cofilin genes that are known to be involved in cell growth, tumor progression, and invasion. In contrast, the repressed genes include type I collagen, lysyl oxidase, annexin I, and tissue inhibitor of matrix metalloproteinase 3 (TIMP3) genes that have been implicated in tumor suppression. In addition, six RET-MEN2A- and five RET-MEN2B-inducible genes were identified. Among 21 genes induced by RET-MEN2A and/or RET-MEN2B, six genes including cyclin D1, cathepsin B, cofilin, ring finger protein 11 (RNF11), integrin-alpha6, and stanniocalcin 1 (STC1) genes were also induced in TGW human neuroblastoma cells in response to glial cell line-derived neurotrophic factor stimulation. Because the STC1 gene was found to be highly induced by both RET-MEN2B and glial cell line-derived neurotrophic factor stimulation, and the expression of its product was detected in medullary thyroid carcinoma with the MEN2B mutation by immunohistochemistry, this may suggest a possible role for STC1 in the development of MEN 2B phenotype. PMID: 12107109 [PubMed - indexed for MEDLINE] DR106: Thyroid. 2002 May;12(5):435-6. Problem of prevalence of ret/PTC rearrangements in thyroid tumors. Saenko VA, Rogounovitch TI, Abrosimov AY, Takamura N, Lushnikov EF, Namba H, Yamashita S. Publication Types: Letter PMID: 12097207 [PubMed - indexed for MEDLINE] DR107: Ann N Y Acad Sci. 2002 Jun;963:116-21. Molecular mechanisms of RET activation in human cancer. Santoro M, Melillo RM, Carlomagno F, Fusco A, Vecchio G. Centro di Endocrinologia ed Oncologia Sperimentale del CNR c/o Dipartimento di Biologia e Patologia Cellulare e Molecolare, Facolta di Medicina e Chirurgia, Universita di Napoli Federico II, 80131 Naples, Italy. Mutations that produce oncogenes with dominant gain of function target receptor protein tyrosine kinases (PTKs) in cancer and confer uncontrolled proliferation, impaired differentiation, or unrestrained survival to the cancer cell. However, insufficient PTK signaling may be responsible for developmental diseases. Gain of function of the RET receptor PTK is associated with human cancer. At the germline level, point mutations of RET are responsible for multiple endocrine neoplasia type 2 (MEN2A, MEN2B, and FMTC). Mutations of extracellular cysteines are found in MEN2A patients, and a Met918Thr mutation is responsible for most MEN2B cases. At the somatic level, gene rearrangements juxtaposing the tyrosine kinase domain of RET to heterologous gene partners are found in papillary carcinomas of the thyroid. These rearrangements generate the chimeric RET/PTC oncogenes. Both MEN2 mutations and PTC gene rearrangements potentiate the intrinsic tyrosine kinase activity of RET and, ultimately, the RET downstream signaling events. A multidocking site of the C-tail of RET is essential for both mitogenic and survival RET signaling. Such a site is involved in the recruitment of several intracellular molecules, such as the Shc, FRS2, IRS1, Gab1/2, and Enigma. The different activating mutations not only potentiate the enzymatic activity of the RET kinase but also may alter qualitatively RET signaling properties by: (1) altering RET autophosphorylation (in the case of the MEN2B mutation), (2) modifying the subcellular distribution of the active kinase, and (3) providing the active kinase with a scaffold for novel protein-protein interactions (as in the case of RET/PTC oncoproteins). This review describes the molecular mechanisms by which the different genetic alterations cause the conversion of RET into a dominant transforming oncogene. PMID: 12095936 [PubMed - indexed for MEDLINE] DR108: Nippon Geka Gakkai Zasshi. 2002 Jun;103(6):492-4. [Thyroid carcinoma: genetics, diagnosis, clinical features, and surgical treatment] [Article in Japanese] Takami H, Ikeda Y, Tajima G, Kan S, Kameyama K. Department of Surgery, Teikyo University School of Medicine, Japan. The genes implicated in thyroid carcinoma can be categorized as oncogenes or tumor-suppressor genes. The RET oncogene has well-established roles in the development of both medullary and papillary thyroid carcinoma (PTC). Genetic testing for the germline RET mutation is commonly performed, and prophylactic thyroidectomy is carried out at an early stage. The demonstration of a RET rearrangement in a PTC patient may be prognostic factor. TSH-R and Gs alpha are associated with the development of toxic thyroid adenoma (AFTN). The ras oncogene is implicated in the early stages of development of several tumor types. In conclusion, germline screening for RET mutations is now commonly undertaken in patients with medullary thyroid carcinoma. PMID: 12094702 [PubMed - indexed for MEDLINE] PR109: Wien Klin Wochenschr. 2002 Apr 15;114(7):274-8. Recommendations for reporting C cell pathology of the thyroid. Kaserer K, Scheuba C, Neuhold N, Weinhausel A, Vierhapper H, Niederle B. Clinical Department of Pathology, Kaiserin Elisabeth Spital, Vienna, Austria. k.kaserer@akh-wien.ac.at BACKGROUND: Calcitonin screening programs have proved to be effective in early detection of medullary thyroid carcinoma, not only in patients with known risk factors for the development of hereditary tumors. Thus, more thyroidectomies, based on an abnormal pentagastrin test, can be expected. Here we give summarizing recommendations for reporting C cell pathology. METHODS: All patients underwent total thyroidectomy and were tested for germ-line mutations in the RET-Protooncogene. The entire surgical specimens were blocked and C-cell disorders were assessed using conventional histology and immunohistochemistry. RESULTS: Among 110 patients with an abnormal pentagastrin test, 60 (55%) had medullary thyroid carcinoma (T1 34% [n = 37], T2 14% [n = 16], T4 6% [n = 7]), and 50 (45%) had C cell hyperplasia only. C cell hyperplasia accompanying medullary thyroid carcinoma was found in 13 of 15 familial and in 28 of 45 sporadic patients. All C cell changes were found in the upper two thirds of the thyroid lobes and 83% of the medullary thyroid carcinomas could be identified with frozen sections. CONCLUSION: 1. Abnormal pentagastrin stimulation is always associated with either medullary thyroid carcinoma or C cell hyperplasia. 2. Blocking of the entire upper two thirds of the thyroid lobes is essential for reliable detection of C cell hyperplasia and small medullary thyroid carcinomas. 3. Most medullary thyroid carcinomas can be detected with intraoperative frozen sections. 4. The presence of C cell hyperplasia should always be reported; however its usefulness for indicating familial risk is limited and its role as a preneoplastic condition in patients without RET-protooncogene mutations remains to be elucidated. PMID: 12089863 [PubMed - indexed for MEDLINE] DR110: J Biol Chem. 2002 Sep 6;277(36):32781-90. Epub 2002 Jun 26. Role of Dok1 in cell signaling mediated by RET tyrosine kinase. Murakami H, Yamamura Y, Shimono Y, Kawai K, Kurokawa K, Takahashi M. Department of Pathology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan. Using a yeast two-hybrid screen, we identified Dok1 as a docking protein for RET tyrosine kinase. Dok1 bound more strongly to RET with a multiple endocrine neoplasia (MEN) 2B mutation than RET with a MEN2A mutation and was highly phosphorylated in the cells expressing the former mutant protein. Analysis by site-directed mutagenesis revealed that tyrosine 361 in mouse Dok1 represents a binding site for the Nck adaptor protein and tyrosines 295, 314, 361, 376, 397, and 408 for the Ras-GTPase-activating protein. We replaced tyrosine 361 or these six tyrosines with phenylalanine (designated Y361F or 6F) in Dok1 and introduced the mutant Dok1 genes into the cells expressing the wild-type RET or RET-MEN2B protein. Overexpression of Dok1 or Dok1-Y361F, but not Dok1-6F, suppressed the Ras/Erk activation induced by glial cell line-derived neurotrophic factor or RET-MEN2B, implying that this inhibitory effect requires the Ras-GTPase-activating protein binding to Dok1. In contrast, overexpression of Dok1, but not Dok1-Y361F or Dok1-6F, enhanced the c-Jun amino-terminal kinase (JNK) and c-Jun activation. This suggested that the association of Nck to tyrosine 361 in Dok1 is necessary for the JNK and c-Jun activation by glial cell line-derived neurotrophic factor or RET-MEN2B. Because a high level of the JNK phosphorylation was observed in the cells expressing RET-MEN2B, its strong activation via Nck binding to Dok1 may be responsible for aggressive properties of medullary thyroid carcinoma developed in MEN 2B. PMID: 12087092 [PubMed - indexed for MEDLINE] DR111: Clin Endocrinol (Oxf). 2002 Jun;56(6):823. A new identified germline mutation of the RET proto-oncogene responsible for familial medullary thyroid carcinoma in co-existence with a hyperfunctioning autonomous nodule. Maschek W, Pichler R, Rieger R, Weinhausel A, Berg J. Publication Types: Case Reports Letter PMID: 12072055 [PubMed - indexed for MEDLINE] DR112: Biochem Biophys Res Commun. 2002 Jun 21;294(4):813-7. Generation and characterization of novel monoclonal antibodies to the Ret receptor tyrosine kinase. Salvatore G, Nagata S, Billaud M, Santoro M, Vecchio G, Pastan I. Laboratory of Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892-4264, USA. Ret is a tyrosine kinase receptor involved in several human diseases germ-line mutations are responsible for multiple endocrine neoplasia type 2 syndromes while somatic mutations of Ret are found in sporadic medullary thyroid carcinomas. In the present work, we describe the generation and characterization of a panel of novel monoclonal antibodies to Ret obtained by immunizing mice with a Ret-FC fusion protein. Fifty-five independent monoclonal antibodies recognize Ret-FC by enzyme linked immunosorbent assay but not a non-related FC fusion protein. Twenty antibodies further characterized recognize Ret expressing cells by flow cytometry. Finally, immunoprecipitation analysis showed that these antibodies recognize Ret mature glycosylated and immature forms. Thus, these monoclonal antibodies could be used as diagnostic tools to detect Ret expression, as well as therapeutic tools to downmodulate Ret or to deliver cytotoxic drugs to malignancies that overexpress Ret as neuroblastomas, medullary and papillary thyroid carcinomas, seminomas, and leukemia. (c) 2002 Elsevier Science (USA). PMID: 12061779 [PubMed - indexed for MEDLINE] DR113: Curr Treat Options Oncol. 2000 Oct;1(4):359-67. Medullary thyroid cancer. Kebebew E, Clark OH. Department of Surgery, University of California, San Francisco, UCSF/Mt. Zion Medical Center, Box 0470, S343, San Francisco, CA 94143, USA. Patients with clinically evident medullary thyroid cancer should have a total extracapsular thyroidectomy with bilateral central neck dissection and an ipsilateral prophylactic or therapeutic modified (functional) radical neck dissection when the primary tumor is greater than 1 cm and when the central neck nodes are positive. A prophylactic contralateral neck dissection should be done when the primary tumor is bilateral and when there is extensive lymphadenopathy on the side of the primary tumor. Patients who have gross, unresectable residual medullary thyroid cancer should receive postoperative external radiotherapy. Patients who are carriers of germ-line RET proto-oncogene point mutations or have an elevated (basal or stimulated) calcitonin levels on screening should have a prophylactic total thyroidectomy before age 6 years. In patients with an elevated basal or stimulated plasma calcitonin level and an intrathyroidal nodule on ultrasound, a total thyroidectomy and central neck lymph node dissection should be done. Patients with persistent or recurrent medullary thyroid cancer should have a complete thyroidectomy (if not done initially) and bilateral central and modified radical neck dissection, including upper mediastinal lymphadenectomy. Patients who are symptomatic from distant medullary thyroid cancer metastases (diarrhea, flushing, weight loss, or bone pain) should be treated with somatostatin analogs. Bone metastases should be resected if possible, and symptomatic lesions that are unresectable should be treated with external radiotherapy. Cytoreductive procedures such as radiofrequency ablation or cryoablation for liver metastases should be considered in symptomatic patients to reduce tumor burden. Localized pulmonary metastases should be resected. Chemotherapy or radioactive immunotherapy (iodine 131 labeled carcinoembryonic antigen monoclonal antibody) protocols should be considered in patients with nonoperative widely metastatic progressing medullary thyroid cancer. Publication Types: Review Review, Tutorial PMID: 12057161 [PubMed - indexed for MEDLINE] PR114: Biochem Biophys Res Commun. 2002 Jun 14;294(3):642-9. Activation of RET tyrosine kinase regulates interleukin-8 production by multiple signaling pathways. Iwahashi N, Murakami H, Nimura Y, Takahashi M. Department of Pathology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan. Interleukin-8 (IL-8) is known to contribute to human cancer progression through its potential function as a mitogenic, angiogenic, or motogenic factor. We found a high level of IL-8 production in SK-N-MC human primitive neuroectodermal tumor cells transfected with the human RET gene (SK-N-MC (RET) cells) in response to glial cell line-derived neurotrophic factor (GDNF) stimulation. IL-8 was also produced at high levels in TT human medullary thyroid carcinoma and TPC-1 human papillary thyroid carcinoma cell lines both of which express activated RET tyrosine kinase. To investigate which signaling pathways are responsible for IL-8 expression, we treated SK-N-MC (RET) cells with several kinase inhibitors before GDNF stimulation. The results showed that a MEK1 inhibitor, PD98059, a p38MAPK inhibitor, SB202190, and a protein kinase C (PKC) inhibitor, Calphostin C, markedly decreased the IL-8 secretion from SK-N-MC (RET) cells at 24 h after GDNF stimulation. In contrast, a phosphatidylinositol 3-kinase (PI3-K) inhibitor, LY294002, increased its secretion. These results thus suggested that IL-8 production by RET tyrosine kinase is regulated by multiple signaling pathways. PMID: 12056817 [PubMed - indexed for MEDLINE] NR115: Horm Res. 2002;57(5-6):197-9. Cortical-sparing laparoscopic adrenalectomy in a patient with multiple endocrine neoplasia type IIA. Porpiglia F, Destefanis P, Bovio S, Allasino B, Orlandi F, Fontana D, Angeli A, Terzolo M. Divisione di Urologia, Dipartimento di Scienze Cliniche e Biologiche, Universita degli Studi di Torino, Italia. We describe the case of a patient affected by multiple endocrine neoplasia type IIA with a new diagnosis of an asymptomatic right pheochromocytoma. The patient underwent laparoscopic adrenalectomy with adrenal sparing. The removal of the tumor was successful with preservation of about one third of the adrenal gland. At the time of the last follow-up, the patient is well with partial hypoadrenalism without replacement therapy. The limitations to cortical-sparing adrenalectomy imposed by traditional open surgery (small tumor with peripheral location) can be reconsidered using the laparoscopic approach. Laparoscopic cortical-sparing adrenalectomy should become the gold standard for treatment of bilateral pheochromocytoma. The advantages of this technique are its efficacy and its reduced invasiveness with a low rate of complications either during the operation or in the postoperative period. Moreover, the preservation of a portion of the adrenal cortex may prevent the need for a life-long steroid replacement therapy. Copyright 2002 S. Karger AG, Basel Publication Types: Case Reports PMID: 12053093 [PubMed - indexed for MEDLINE] DR116: BMC Genet. 2002 May 31;3(1):8. The minisequencing method: a simple strategy for genetic screening of MEN 2 families. Bugalho MJ, Domingues R, Sobrinho L. Centro de Investigacao de Patobiologia Molecular, Instituto Portugues de Oncologia FG / Lisboa, Portugal. mjbugalho@ipolisboa.min-saude.pt BACKGROUND: Multiple endocrine neoplasia type 2 is an autosomal dominant disorder. MEN 2A is characterized by medullary thyroid carcinoma, pheochromocytoma and hyperparathyroidism; MEN 2B by medullary thyroid carcinoma, pheochromocytoma and characteristic stigmata. Activating germline mutations of the RET proto oncogene are responsible for this hereditary syndrome. Codon 634 mutations are the most common mutations occurring in MEN 2A families whereas a specific mutation at codon 918 is observed in the great majority of MEN 2B families. Analysis of these codons will provide a final diagnosis in the great majority of affected families making unnecessary further studies. To specifically study the codons 634 and 918 we used a minisequencing method as an alternative method to complete sequencing. RESULTS: Using this mutation detection method we were able to reproduce in all cases, representative of 7 families, the information previously obtained by direct sequencing of PCR products. Depending on the number of primers used in the minisequencing reaction, we were able to interrogate either only one nucleotide of the target codon or the three nucleotides simultaneously. CONCLUSIONS: This technique appears as a simple, rapid and efficient method for genetic screening of MEN 2 families. It can be utilized to seek for unknown mutations at specific codons or to screen for previously identified mutations and is therefore of interest to study index cases or individuals at risk. Results suggest that complete sequencing is unnecessary. Publication Types: Evaluation Studies PMID: 12042015 [PubMed - indexed for MEDLINE] DR117: J Pediatr Surg. 2002 Jun;37(6):897-900. Multiple endocrine neoplasia 2A syndrome: Surgical management. Simon S, Pavel M, Hensen J, Berg J, Hummer HP, Carbon R. Department of Paediatric Surgery, Surgical Clinic of the Friedrich-Alexander-Universitat Erlangen, Erlangen, Germany. BACKGROUND/PURPOSE: Currently, molecular genetic diagnostics allow familial types of medullary thyroid carcinoma to be detected at an asymptomatic stage and surgery thus to be performed at a time when prognosis is good. The current report aims to determine the appropriate age for safe prophylactic thyroidectomy in children with multiple endocrine neoplasia (MEN) 2A and mutations at codon 609 according to genotype-phenotype correlations and will discuss surgical procedures. METHODS: The authors describe the case of a family with hereditary MEN 2A syndrome. A DNA analysis of 7 family members confirmed the diagnosis by a mutation at codon 609 of the RET proto-oncogene. RESULTS: A phaeochromocytoma developed in 2 family members. Four had medullary thyroid carcinoma. A grandson underwent a prophylactic thyroidectomy at the age of 5 on account of genetic evidence. Despite the negative preoperative and intraoperative findings he already had an invasive medullary thyroid carcinoma. CONCLUSIONS: Few genotype-phenotype correlations have been established for MEN 2A disease. According to the natural history of the disease, families with the genotype RET cys609gly should have a more benign disease than high-risk families (mutations at codon 634, 618). From this report the authors conclude that prophylactic thyroidectomy in "609" families should be performed earlier than actually recommended, favorably at the age of 2 to 4 years. Further multicenter studies are needed to provide more clinical and prognostic data for less frequent (codon 609, 630, 791, and 891) RET genotypes. Copyright 2002, Elsevier Science (USA). All rights reserved. Publication Types: Case Reports PMID: 12037758 [PubMed - indexed for MEDLINE] NR118: Cancer Res. 2002 Jun 1;62(11):3048-51. Recessive transmission of a multiple endocrine neoplasia syndrome in the rat. Fritz A, Walch A, Piotrowska K, Rosemann M, Schaffer E, Weber K, Timper A, Wildner G, Graw J, Hofler H, Atkinson MJ. Institute of Pathology, GSF-National Research Center for Environment and Health, Ingolstaedter Landstrasse 1, D-85764 Neuherberg, Germany. We describe a novel hereditary cancer syndrome in the rat that is transmitted by a recessive gene mutation. Animals exhibiting the mutant phenotype develop multiple neuroendocrine malignancies within the first year of life. The endocrine neoplasia is characterized by bilateral adrenal pheochromocytoma, multiple extra-adrenal pheochromocytoma, bilateral medullary thyroid cell neoplasia, bilateral parathyroid hyperplasia, and pituitary adenoma. The appearance of neoplastic disease is preceded by the development of bilateral juvenile cataracts. Although the spectrum of affected tissues is reminiscent of human forms of multiple endocrine neoplasia (MEN), no germ-line mutations were detected in the Ret or Menin genes that are responsible for the dominantly inherited MEN syndromes in humans. Segregation studies in F1 and F2 crosses yielded frequencies of affected animals entirely consistent with a recessive autosomal mode of inheritance. The lack of the phenotype in F1 animals effectively excludes a germ-line tumor suppressor gene mutation as the causal event. The absence of mutation of known MEN genes and the unique constellation of affected tissues, plus the recessive mode of inheritance, lead us to conclude that the mutation of an as yet unknown gene is responsible for this syndrome of inherited neuroendocrine cancer. PMID: 12036912 [PubMed - indexed for MEDLINE] DR119: BMC Med Genet. 2002 May 21;3(1):4. Epub 2002 May 21. A PCR-mutagenesis strategy for rapid detection of mutations in codon 634 of the ret proto-oncogene related to MEN 2A. Roque M, Pusiol E, Perinetti H, Godoy CP, Mayorga LS. Laboratorio de Biologia Celular y Molecular, IHEM (UNCuyo-CONICET), Facultad de Ciencias Medicas, Universidad Nacional de Cuyo, Mendoza, Argentina. paine1@nysnet.com.ar BACKGROUND: Multiple endocrine neoplasias type 2A (MEN 2A) is a dominantly inherited cancer syndrome. Missence mutations in the codon encoding cysteine 634 of the ret proto-oncogene have been found in 85% of the MEN 2A families. The main tumour type always present in MEN 2A is medullar thyroid carcinoma (MTC). Only 25% of all MTC are hereditary, and generally they are identified by a careful family history. However, some familial MTCs are not easily detected by this means and underdiagnosis of MEN 2A is suspected. METHODS: DNA samples from MEN 2A patients were amplified by PCR. The products were incubated with the restriction enzyme Bst ApI or Bgl I.The samples were loaded in non-denaturing 10% Polyacrilamyde Gel and run at 120 volts for 40 min. The gels were stained with 10 microg/ml ethidium bromide, and the bands were visualized under a UV lamp. RESULTS: We developed a PCR-mutagenic method to check the integrity of the three bases of the cysteine 634 codon. CONCLUSION: The method can be used to detect inherited mutations in MTC patients without a clear family history. The method is relatively simple to use as a routine test in these patients to decrease the underdiagnosis of MEN 2A. In addition, the assay can be used to screen affected families with any mutation in cysteine 634. PMID: 12033991 [PubMed] DR120: Surgery. 2002 May;131(5):509-14. V804M RET mutation and familial medullary thyroid carcinoma: report of a large family with expression of the disease only in the homozygous gene carriers. Lecube A, Hernandez C, Oriola J, Galard R, Gemar E, Mesa J, Simo R. Department of Endocrinology, Hospital Vall d'Hebron, Barcelona, Spain. BACKGROUND: Only 9 families with familial medullary thyroid carcinoma due to V804M mutation have been reported until now. We describe a large kindred with not only heterozygous but also homozygous members with the V804M mutation. This is, to our knowledge, the first report of a homozygous RET mutation. METHODS: Fifty-three members from 4 successive generations of a family with a high level of consanguinity underwent genetic analysis. The pentagastrin provocative test and biochemical screening to rule out either hyperparathyroidism or pheochromocytoma were performed only on gene carriers of the mutation. RESULTS: Twenty-six gene carriers for V804M mutation were identified (4 homozygous and 22 heterozygous). Three of 4 homozygous patients underwent total thyroidectomy. In 1 patient neither medullary thyroid carcinoma nor C-cell hyperplasia was detected, and in another patient only 3 small foci of C-cell hyperplasia were found on the histologic examination. The pentagastrin stimulation test result was within the normal range in all the heterozygous gene carriers and, consequently, thyroidectomy was not indicated. The screening for both hyperparathyroidism and pheochromocytoma was negative in all patients. CONCLUSIONS: In the family reported, the V804M mutation in heterozygous patients seems not to be enough to express the full disease. This finding strongly supports the concept of the indolent behavior of V804M RET proto-oncogene mutation. In addition, our results suggest that when counseling for preventive total thyroidectomy, the specific mutation of RET proto-oncogene and also the natural history of the disease within a particular family should be considered. PMID: 12019403 [PubMed - indexed for MEDLINE] DR121: World J Surg. 2002 Aug;26(8):1023-8. Epub 2002 May 21. Prospective trial of unilateral surgery for nonhereditary medullary thyroid carcinoma in patients without germline RET mutations. Miyauchi A, Matsuzuka F, Hirai K, Yokozawa T, Kobayashi K, Ito Y, Nakano K, Kuma K, Futami H, Yamaguchi K. Department of Surgery, Kuma Hospital, 8-2-35 Shimoyamate-dori, Chuo-ku, Kobe 650-0011, Japan. miyauchi@kuma-h.or.jp Although sporadic medullary thyroid carcinoma (MTC) tends to be unicentric and confined to one lobe, total thyroidectomy is usually performed because of the risk of a hereditary or bilateral process. Germline RET mutation analysis can discriminate hereditary MTC and truly sporadic, nonhereditary MTC. We analyzed 72 of 94 patients with MTC to establish the genetic nature and the clinical features of nonhereditary MTC. Since 1996 we have prospectively treated 15 patients with nonhereditary MTC (prospective study group, or PSG) according to a unilateral surgery policy. A group of 22 previously operated patients in whom the nonhereditary nature was established served as controls (retrospective study group, or RSG). Systematic central and ipsilateral neck dissection was performed in both groups. Outcome was assessed using postoperative stimulated serum calcitonin levels; a normal value was considered a biochemical cure. All 24 hereditary MTC patients carried germline RET mutations: 8 of 48 patients with apparently sporadic MTC had the mutations, and 6 of the 8 had bilateral MTC. All 40 patients without mutations had a unilateral tumor. In the RSG group 15 of 22 (68%) patients underwent total thyroidectomy, and the biochemical cure rate was 68%. Although only 3 of 15 (20%) of the PSG patients underwent total thyroidectomy, 12 of the 15 (80%) achieved biochemical cure. Univariate analyses revealed that pathologic node involvement- high T and N stages-was adversely related to biochemical cure. The extent of thyroid resection was not related to biochemical cure. Of 20 patients with node involvement, 10 achieved biochemical cure, indicating the importance of systematic neck dissection. Hemithyroidectomy with systematic central and ipsilateral neck dissection is appropriate surgery for nonhereditary MTC. Publication Types: Evaluation Studies PMID: 12016484 [PubMed - indexed for MEDLINE] DR122: Horm Metab Res. 2002 Apr;34(4):202-6. Molecular and biochemical screening for the diagnosis and management of medullary thyroid carcinoma in multiple endocrine neoplasia type 2A. Vieira AE, Mello MP, Elias LL, Lau IF, Maciel LM, Moreira AC, Castro M. Department of Clinical Pathology, University of Campinas, Brazil. Patients with Multiple Endocrine Neoplasia (MEN) type 2A are at risk for early medullary thyroid carcinoma (MTC). We performed different screening tests for MTC--a recently reported biochemical screening test using omeprazole-induced calcitonin (CT) stimulation and DNA analysis--in fifteen members of two non-consanguineous Brazilian families with MEN 2A. RET proto-oncogene analysis was carried out by direct DNA sequencing of PCR-amplified products for exons 10 and 11. Family 1 showed a germline mutation (C634Y) in three individuals; a sister and a brother with symptomatic MTC; the former also presented with pheochromocytoma and hyperparathyroidism, and her son was a nine-year-old boy of previously unknown status. Family 2 showed the C634R mutation only in the index case, who presented with cutaneous lichen amyloidosis in addition to MTC, pheochromocytoma and hyperparathyroidism. Neither her parents nor her four brothers showed this genetic abnormality, suggesting a de novo RET proto-oncogene mutation in this patient. The controls and patients presented normal basal gastrin levels and a significant increase after omeprazole. Basal CT levels were elevated in patients with MTC and undetectable in control and asymptomatic family members. No subject showed any increase in CT levels after omeprazole treatment. In conclusion, the two most frequent RET proto-oncogene mutations in MEN 2A are present in Brazilian families. In addition, the specificity of basal and omeprazole-stimulated calcitonin is rather limited, and the efficacy of the omeprazole test still needs to be systematically examined. Therefore, RET proto-oncogene analysis must be the first choice for a screening procedure to identify gene carriers in MEN 2A family members and to permit early prophylactic treatment of MTC. Publication Types: Case Reports PMID: 11987030 [PubMed - indexed for MEDLINE] PR123: Endocr Pract. 2002 Jan-Feb;8(1):19-22. Comment in: Endocr Pract. 2002 Jan-Feb;8(1):72-4. Early onset of medullary thyroid carcinoma in a kindred with multiple endocrine neoplasia type iia associated with cutaneous lichen amyloidosis. Lemos MC, Carrilho F, Rodrigues FJ, Santos P, Carvalheiro M, Ruas MA, Regateiro FJ. Servico de Endocrinologia, Diabetes e Metabolismo, Hospitais da Universidade de Coimbra, Coimbra, Portugal. OBJECTIVE: To describe the molecular characterization of a kindred affected by the rare variant of multiple endocrine neoplasia type IIA (MEN IIA) associated with cutaneous lichen amyloidosis and to discuss the clinical implications in the management of this syndrome. METHODS: A kindred with four affected family members was identified, and DNA analysis was performed by sequencing exon 11 of the RET proto-oncogene. Presymptomatic genetic screening was offered to all first-degree relatives. RESULTS: Sequencing analysis of the RET proto-oncogene revealed a Cys634Trp (TGC->TGG) mutation in all clinically affected family members and in an asymptomatic 5-year-old child who, after thyroidectomy, was found to have multicentric medullary thyroid carcinoma and C-cell hyperplasia. A Gly691Ser (GGT->AGT) polymorphism was also detected in this family but did not segregate with the disease. CONCLUSION: To our knowledge, this is the earliest detection of medullary thyroid carcinoma reported thus far in a kindred with MEN IIA associated with cutaneous lichen amyloidosis, and this finding suggests that prophylactic thyroidectomy, in kindreds with this variant, should be performed before the age of 5 years. Publication Types: Case Reports PMID: 11939755 [PubMed - indexed for MEDLINE] DR124: Pediatr Med Chir. 2002 Jan-Feb;24(1):53-7. [Prophylactic total thyroidectomy in children and adolescents with genetic mutations in the RET-protooncogene.] [Article in Italian] Spinelli C, Puccini M, Bertocchini A, Lima M, Pacini F, Miccoli P. Dipartimento di Chirurgica Generale, Universita di Pisa, Via Roma, 67, Pisa. Medullary thyroid cancer (C.M.T.) can be a sporadic form generally in adults or a heredofamilial form where the first symptom appears in pediatric and adolescent age. The hereditary form can be isolated or associated with others endocrine neoplasias of type 2: MEN2a (with or without cutaneous lichen amyloidosis) and MEN2b. The responsible gene of the transmission has been identified in proto-oncogene RET localized on chromosome 10. Point form mutations of this proto-oncogene have been found on exons 10 and 11 in MEN2a and on 16 in MEN2b. In our study on 64 subjects, who belong 11 familiar groups, affected by MEN2a, MEN2b and familiar C.M.T., underwent a genetic research to look for point form mutations of proto-oncogene RET with PCR followed by the analysis of restriction. A genetic mutation has been revealed in 25 subjects: 18 were already known affected by MEN2 and so surgical treated and 7 seemed healthy (mean age 17.4 years, range 10-25). These 7 patients has been undergone clinical research and surgical treatment: a total thyroidectomy associated a lymphectomy of the central compartment. In all cases the histological exam showed C.M.T. moreover a patient had metastasis in lymph nodes of the central compartment. Another had hyperparathyroidism and pheochromocytoma treated with total thyroidectomy, parathyroidectomy and bilateral laparoscopic adrenalectomy. The identification in a very early age of carrier subjects of hill's gene inside an affected family, permits the execution of a prophylactic total thyroidectomy to prevent the C.M.T.. The penetrance of this neoplasia in hereditary form is 100%. PMID: 11938683 [PubMed - indexed for MEDLINE] DR125: Surgery. 2002 Apr;131(4):373-81. Comment in: Surgery. 2002 Apr;131(4):382-3. RET mutation profile and variable clinical manifestations in a family with multiple endocrine neoplasia type 2A and Hirschsprung's disease. Pasini B, Rossi R, Ambrosio MR, Zatelli MC, Gullo M, Gobbo M, Collini P, Aiello A, Pansini G, Trasforini G, degli Uberti EC. Department of Biomedical Sciences and Advanced Therapies, Section of Endocrinology, University of Ferrara, Via Savonarola 9, I-44100 Ferrara, Italy. BACKGROUND: RET proto-oncogene germ line mutations are associated with the inherited multiple endocrine neoplasia type 2 syndromes (MEN 2), as well as with familial and sporadic Hirschsprung's disease (HSCR). In this study, we report a family in which the MEN 2A and the HSCR phenotypes are associated with a single point mutation in exon 10 of the RET proto-oncogene. Furthermore, we have investigated polymorphic sequence variants of the RET proto-oncogene. METHODS: Family members were tested for RET proto-oncogene mutations in exons 10, 11, 13, 14, 15, and 16 by double-gradient denaturing-gradient gel electrophoresis, nucleotide sequence analysis, and restriction endonuclease digestion of polymerase chain reaction products. The status of exon 2 and 13 polymorphic sites was investigated by EagI and TaqI digestion in 12 selected patients. RESULTS: A heterozygous C618R mutation of RET exon 10 was identified in 12 family members. Five out of 7 children with mildly elevated pentagastrin-stimulated calcitonin levels who carried the mutation underwent prophylactic thyroidectomy before the age of 12. C-cell hyperplasia (CCH) was found in 4 children and a microscopic medullary thyroid carcinoma (MTC) in an 8-year-old female. Neither CCH nor MTC was found in the only family member affected with HSCR, an 8-year-old male. This patient inherited the mutated RET allele from his mother, who had MTC but not HSCR, together with a rare allelic variant at codon 45 of RET exon 2. CONCLUSIONS: This report of a newly-described kindred with the infrequent clinical association between MEN 2A and HSCR confirms the risk of the latter phenotype among carriers of RET exon 10 cysteine codon mutations. Nevertheless, the influence of other genetic or environmental factors cannot be excluded. Publication Types: Case Reports PMID: 11935126 [PubMed - indexed for MEDLINE] DR126: J Clin Endocrinol Metab. 2002 Apr;87(4):1674-80. Familial medullary thyroid carcinoma: clinical variability and low aggressiveness associated with RET mutation at codon 804. Lombardo F, Baudin E, Chiefari E, Arturi F, Bardet S, Caillou B, Conte C, Dallapiccola B, Giuffrida D, Bidart JM, Schlumberger M, Filetti S. Department de Biologie Clinique and Service de Medecine Nucleaire, Institut Gustave Roussy, Villejuif, France. Sixty-one heterozygotes harboring the germline V804L mutation of the RET protooncogene were identified in five independent families. A total of 31 subjects underwent surgery. Histology identified C cell hyperplasia in 30 cases, isolated in 12 and associated with medullary thyroid carcinoma (MTC) in 18. Six patients with MTC had lymph node metastases. Among the 14 patients with basal detectable calcitonin (CT) level, 12 had MTC and 2 had isolated C cell hyperplasia. In most individuals carrying 804 RET mutation, C cell disease displayed late onset and an indolent course; a pentagastrin test was negative in the majority of heterozygotes during the first 2 decades and was positive in only half of them during the third and fourth decades of life. Interestingly, concomitant somatic M918T was detected in a 12-yr-old girl with MTC and was likely to be responsible for both the early clinical appearance and the aggressiveness of the disease. Our data show that in these gene carriers, surgery may be postponed to the fourth decade of life or until the pentagastrin stimulation test becomes positive. Indeed, our data should be confirmed on a larger series of V804L carriers, but may offer a balanced strategy to keep under control and prevent development of the full disease phenotype. PMID: 11932300 [PubMed - indexed for MEDLINE] DR127: Endocr Pathol. 2001 Winter;12(4):365-77. C-cell hyperplasia and medullary thyroid microcarcinoma. Albores-Saavedra JA, Krueger JE. Department of Pathology, UT Southwestern Medical Center, 5323 Harry Hines Blvd. Dallas, TX 75390-9073, USA. Since the discovery of the thyroid C-cell, considerable progress has been made regarding its origin, function, and pathology. In this article an attempt is made to summarize and update our knowledge about physiologic or reactive C-cell hyperplasia, neoplastic C-cell hyperplasia (medullary carcinoma in situ), and medullary microcarcinoma. Seldom recognized preoperatively, physiologic C-cell hyperplasia is associated with inflammatory, metabolic, and neoplastic thyroid disorders as well as with hypercalcemia. However, the pathogenesis is still unclear. Although physiologic C-cell hyperplasia may progress to medullary carcinoma, the full malignant potential is unknown. Problems related to the definition of physiologic C-cell hyperplasia are discussed. Immunohistochemistry and quantitative analysis are required for the diagnosis. By contrast, C-cell hyperplasia associated with MEN II syndromes or familial medullary carcinoma can be diagnosed preoperatively in asymptomatic children or adolescents by the detection of germline mutations of the RET protooncogene. Morphologic and genetic abnormalities support the idea that C-cells in the familial form of C-cell hyperplasia are neoplastic and can be recognized with conventional stains. Therefore, the number of C-cells is irrelevant for the diagnosis. Medullary microcarcinoma is a neoplasm that measures < 1 cm. The sporadic variant is usually an incidental microscopic finding, whereas the familial form can be diagnosed by genetic testing. Its morphologic features and biologic behavior differ from those of larger medullary carcinomas. The frequency of medullary microcarcinoma will probably increase with the use of genetic testing. Publication Types: Review Review, Tutorial PMID: 11914470 [PubMed - indexed for MEDLINE] DR128: Cancer. 2002 Jan 15;94(2):323-30. Very early detection of RET proto-oncogene mutation is crucial for preventive thyroidectomy in multiple endocrine neoplasia type 2 children: presence of C-cell malignant disease in asymptomatic carriers. Sanso GE, Domene HM, Garcia R, Pusiol E, de M, Roque M, Ring A, Perinetti H, Elsner B, Iorcansky S, Barontini M. Centro de Investgaciones Endocrinologicas, Hospital de Ninos R. Gutierrez, Buenos Aires, Argentina. BACKGROUND: Multiple endocrine neoplasia type 2 (MEN 2) is an inherited disease caused by germline mutations in the RET proto-oncogene, and is responsible for the development of endocrine neoplasia. Its prognosis is dependent on the appearance and spread of medullary thyroid carcinoma (MTC). Relatives at risk can be identified before clinical or biochemical signs of the disease become evident. METHODS: Twenty-one families with MEN 2 (16 families with MEN 2A and 5 families with MEN 2B) were studied. Peripheral blood DNA was amplified by polymerase chain reaction. DNA sequence or restriction enzyme analysis was performed to detect mutations of RET proto-oncogene exons 10, 11, and 16. Molecular analysis was carried out in all index patients as well as in 98 relatives of MEN 2A patients (60 juveniles, ages 6 months to 21 years, and 38 adults, ages 22 to 81 years) and in 13 relatives (6 juveniles ages 10 to 21 years, and 7 adults ages 41 to 66 years) from MEN 2B families. RESULTS: Molecular studies showed a mutation at codon 634, exon 11 in all MEN 2A patients. All MEN 2B patients showed an ATG to ACG (Met918Thr) mutation. In MEN 2A families, 42 out of 98 relatives were affected. Total thyroidectomy was performed in 18 juvenile carriers ages 17 months to 21 years. Histopathologic studies of the glands revealed parafollicular cell (C-cell) hyperplasia in all of these carriers, medullary thyroid carcinoma in 15 carriers, and only one carrier with lymph node metastases. CONCLUSIONS: The consistent finding of C-cell disease in all the juvenile carriers who underwent preventive thyroidectomy emphasizes the relevance of early screening in children at risk of developing MTC. The presence of MTC in the specimen of prophylactic thyroidectomy from a 17 month old girl highlights the importance of thyroidectomy as soon as the molecular diagnosis is confirmed. PMID: 11900218 [PubMed - indexed for MEDLINE] DR129: J Clin Endocrinol Metab. 2002 Mar;87(3):1120-8. Functionally impaired TR mutants are present in thyroid papillary cancer. Puzianowska-Kuznicka M, Krystyniak A, Madej A, Cheng SY, Nauman J. Department of Endocrinology, Medical Research Center, Polish Academy of Sciences, 02-097 Warsaw, Poland. monika@amwaw.edu.pl TRs are transcription factors that regulate cell proliferation, differentiation, and apoptosis. They are cellular homologs of the transcriptionally inactive viral oncogene v-erbA. We tested the hypothesis that the functions of TRs could be impaired in cancer tissues as a result of aberrant expression and/or somatic mutations. As a model system, we selected human thyroid papillary cancer, in which the most common abnormalities, RET/papillary thyroid cancer rearrangements (fusion of RET kinase domain to the activating domains of other genes), were found in 40--45% of cases. We found that the mean expression levels of TR beta mRNA and TR alpha mRNA were significantly lower, whereas the protein levels of TR beta 1 and TR alpha 1 were higher in cancer tissues than in healthy thyroid. Sequencing of TR beta 1 and TR alpha 1 cDNAs, cloned from 16 papillary cancers, revealed that mutations affected receptor amino acid sequences in 93.75% and 62.5% of cases, respectively. In contrast, no mutations were found in healthy thyroid controls, and only 11.11% and 22.22% of thyroid adenomas had such TR beta 1 or TR alpha 1 mutations, respectively. The majority of the mutated TRs lost their trans-activation function and exhibited dominant negative activity. These findings suggest a possible role for mutated thyroid hormone receptors in the tumorigenesis of human papillary thyroid carcinoma. PMID: 11889175 [PubMed - indexed for MEDLINE] DR130: J Endocrinol Invest. 2002 Jan;25(1):25-31. Comment in: J Endocrinol Invest. 2003 Apr;26(4):381-3. The finding of a somaticdeletion in RET exon 15 clarified the sporadic nature of amedullary thyroid carcinoma suspected to be familial. Oriola J, Halperin I, Rivera-Fillat F, Donis-Keller H. Department of Hormonology, IDIBAPS, Hospital Clinic i Universitari, Barcelona, Spain. joriola@clinic.ub.es Medullary thyroid carcinoma (MTC) occurs both sporadically and in the autosomal dominantly inherited multiple endocrine neoplasia (MEN) type 2 syndromes. The distinction between both is important for future clinical management. We report a family initially described as a familial MTC by pentagastrin stimulation test and clinical outcome, in which we found a 12 bp deletion within the catalytic domain of the protooncogene RET in the index case tumor alone. Linkage study suggests that it is a sporadic MTC. Therefore, in view of these results, in kindred with just one MTC case, borderline pentagastrin test values must be carefully assessed. In addition, this and other mutations can help us to understand some features about domains that play an important role in the normal function of this tyrosine kinase receptor and involved in MTC. PMID: 11883863 [PubMed - indexed for MEDLINE] DR131: Clin Endocrinol (Oxf). 2002 Jan;56(1):53-63. Erratum in: Clin Endocrinol (Oxf) 2002 Apr;56(4):563. Multigenerational familial medullary thyroid cancer (FMTC): evidence for FMTC phenocopies and association with papillary thyroid cancer. Fugazzola L, Cerutti N, Mannavola D, Ghilardi G, Alberti L, Romoli R, Beck-Peccoz P. Istituto Clinico Humanitas and Ospedale Maggiore IRCCS, Milan, Italy. BACKGROUND: Occurrence in a familial setting is well established for medullary thyroid carcinoma (MTC) and has been more recently reported for papillary thyroid cancer (PTC). Germline mutations or rearrangements of the RET proto-oncogene are the genetic background of the majority of hereditary MTCs and of about 25-40% of PTCs. PATIENTS: A large multigenerational familial medullary thyroid cancer (FMTC) family, comprised of four generations and a total of 60 subjects, has been fully evaluated. Studies on germline RET mutations and polymorphisms, on somatic RET activation and on haplotyping with RET-linked markers, were performed. RESULTS: RET mutational analysis revealed a rare missense point mutation in exon 15 of RET (A891S), associated with FMTC. Haplotype analysis showed a co-segregation between the allelic variant 5 of D10S578 marker (which is tightly linked to the RET locus) and the RET mutation. Two patients, from different branches of the family, did not harbour the point mutation A891S despite histological confirmation of MTC. In these cases, haplotype analysis excluded the involvement of the RET gene itself in the pathogenesis of the MTC. In three patients, the coexistence, in different foci, of medullary and papillary thyroid cancer was documented. The genetic studies did not show ret/PTC rearrangements. The microsatellite analysis excluded co-segregation of RET locus with the MTC/PTC phenotype. CONCLUSIONS: We report a full clinical and molecular analysis of a large FMTC kindred with an uncommon RET mutation. In two family members, phenotype and genotype were not concordant, representing the first evidence of FMTC phenocopies. Furthermore, the association of familial forms of medullary and papillary thyroid cancers has been found in 30% of patients undergoing thyroidectomy for MTC. In these situations, genetic analyses excluded the possible germline involvement of RET. Though FMTC phenocopies are likely to represent an exceptional finding, such a possibility should be taken into account in the genetic counselling for MEN 2 syndromes. PMID: 11849247 [PubMed - indexed for MEDLINE] DR132: Neoplasma. 2001;48(5):325-31. Cancers connected with mutations in RET proto-oncogene. Altanerova V. Cancer Research Institute, Slovak Academy of Sciences, Bratislava. exonalta@savba.sk Germline mutations of RET proto-oncogene are connected with inherited cancer syndrome multiple endocrine neoplasia type 2. The syndrome is characterized by incidence of medullary thyroid carcinoma frequently associated with pheochromocytoma and hyperparathyroidism. Genetic testing of family members at risk significantly contributed to diagnosis and management of MEN 2. Early genetic screening for RET mutations allow to detect people who have inherited the MEN2 specific RET mutation with subsequent possibility to of prophylactic thyroidectomy. On the other hand those family members at risk of MEN 2 who had not inherited the mutation do not require further testing. The involvement of RET proto-oncogene in tumorigenesis is reviewed. Publication Types: Review Review, Tutorial PMID: 11845976 [PubMed - indexed for MEDLINE] DR133: Clin Cancer Res. 2002 Feb;8(2):457-63. RET oligonucleotide microarray for the detection of RET mutations in multiple endocrine neoplasia type 2 syndromes. Kim IJ, Kang HC, Park JH, Ku JL, Lee JS, Kwon HJ, Yoon KA, Heo SC, Yang HY, Cho BY, Kim SY, Oh SK, Youn YK, Park DJ, Lee MS, Lee KW, Park JG. Familial Cancer Clinic, National Cancer Center, 809 Madu-dong, Ilsan-gu, Goyang, Gyeonggi 411-764, Korea. Multiple endocrine neoplasia type 2 (MEN2) syndromes are inherited in an autosomal dominant fashion with high penetrance. There are three subtypes, namely, MEN2A (multiple endocrine neoplasia type 2A), MEN2B (multiple endocrine neoplasia type 2B), and familial medullary thyroid carcinoma. The variations in the RET gene play an important role in the MEN2 syndromes. In this work, we have developed a RET oligonucleotide microarray of 67 oligonucleotides to quickly detect RET mutations in MEN2 syndromes. The predominant RET mutations are missense mutations and are restricted to nine codons (codons 609, 611, 618, 620, 630, 634, 768, 804, and 918) in MEN2 syndromes. Missense mutations at codons 609, 611, 618, 620, and 634 have been identified in 98% of MEN2A families and in 85% of familial medullary thyroid carcinoma families. More than 95% of MEN2B patients also had a predominant mutation type at codon 918 (Met-->Thr). RET oligonucleotide microarray can detect RET missense mutations at these nine codons. Theoretically, a total of 55 missense mutation types can occur at eight codons (codons 609, 611, 618, 620, 630, 634, 768, and 804). RET oligonucleotide microarray is designed to detect all of these 55 missense mutation types at these eight codons and one predominant type at codon 918. Fifty-six oligonucleotides were designed for the 56 mutation types at nine codons, and 11 oligonucleotides were designed for the wild types and positive controls. We found RET mutations in all eight of the Korean MEN2A families (a total of 75 members; 27 affected members, 19 gene carriers, and 29 unaffected members) using the developed RET oligonucleotide microarray and an automatic sequencing. Because we found only five mutation types from eight MEN2A families, the international collaborations are required to see whether the RET oligonucleotide microarray may be used as a genetic diagnostic tool. Taken together, the RET oligonucleotide microarray can function as a fast and reliable genetic diagnostic device, which simplifies the process of detecting RET mutations. PMID: 11839664 [PubMed - indexed for MEDLINE] DR134: Folia Histochem Cytobiol. 2001;39 Suppl 2:26-7. Molecular changes in thyroid neoplasia. Jarzab B, Wloch J, Wiench M. Dept of Nuclear Medicine and Endocrine Oncology, Clinic of Oncological Surgery, Maria Sklodowska-Curie Memorial Institute, Gliwice, Poland. bjarzab@io.gliwice.pl All authors integrating the known facts into a model of thyroid carcinogenesis concur that two main histotypes of thyroid cancer exhibit different routes of molecular development. RET rearrangements are an initiating event in papillary carcinoma, and simultaneously the most characteristic mutation for this type of cancer. They are followed by further, not well recognized, mutations. RAS mutations are regarded as a crucial event in the development of follicular tumors already at the adenoma step, while in papillary cancer they belong to the spectrum of secondary mutations, enabling tumor progression. Aberrant DNA methylation, causing loss of P16 tumor supressor gene, may be a common event in both types of cancer. Aneuploidy is seen much more frequently in follicular than in papillary cancer, which also exhibits a low rate for loss of heterozygosity and microsatellite instability. Mutations of the P53 tumor supressor gene are a common feature of undifferentiated thyroid cancers and could be responsible for their aggressive phenotype. RET rearrangements have been proposed as identifying fingerprints for irradiation induced thyroid cancer in children. Our own data speak against this hypothesis. We noted a high frequency of RET/PTC3 mutations in a group of Polish children with papillary thyroid carcinoma, regarded as sporadic cancer. Publication Types: Review PMID: 11820615 [PubMed - indexed for MEDLINE] PR135: J Endocrinol Invest. 2001 Dec;24(11):892-6. Medullary thyroid cancer, papillary thyroid microcarcinoma and Graves' disease: an unusual clinical coexistence. Mazziotti G, Rotondi M, Manganella G, Franco R, Capone PFRS, Colantuoni V, Amato G, Carella C. Endocrinology Institute, Second University of Naples, Italy. We describe the unusual case of a Caucasian woman who had a diagnosis of medullary thyroid cancer and papillary microcarcinoma 5 years after a diagnosis of Graves' disease. The patient came to our observation for recurrence of hyperthyroidism. An ultrasound scan revealed diffuse thyroid enlargement with a nodule, recently increased in size. The serum CT and carcinoembrional antigen were elevated, and the fine-needle aspiration cytology with immunocytochemical analysis for CT was suggestive for medullary thyroid carcinoma. The nodular lesion showed intense 111In-pentetreotide uptake, whereas total body scintigraphy with the same tracer and with Thallium-201, 99mTc (V) dimercaptosuccinic acid was negative for lymph node and distant metastasis. The histological examination of thyroidectomy specimens confirmed the diagnosis of medullary thyroid cancer, showing a lymphocytic intratumoral infiltration. The histological analysis of the controlateral lobe showed an occult papillary microcarcinoma. Medullary thyroid carcinoma and papillary microcarcinoma showed intense staining with policlonal anti-RET antibodies, although genetic analysis was negative for RET mutations most frequently involved in familial and sporadic medullary thyroid carcinomas. Possible implications about the coexistence of the 3 thyroid diseases are discussed. Publication Types: Case Reports PMID: 11817715 [PubMed - indexed for MEDLINE] NR136: Horm Res. 2001;56(1-2):63-6. Thyroid C-cell hyperplasia in an adolescent with neurofibromatosis type 1. Segni M, Massa R, Bonifacio V, Tartaglia F, Pucarelli I, Marzullo A, Pasquino AM. Department of Pediatrics, University 'La Sapienza', Rome, Italy. m.segni@mclink.it BACKGROUND: Subjects with neurofibromatosis type 1 (NF1) show an increased risk of endocrine tumors, especially pheochromocytoma, whereas thyroid C-cell hyperplasia (CCH) and medullary thyroid carcinoma (MTC) are very rare events described only in adult patients. METHOD: A case of CCH diagnosed in a 14-year-old girl affected with NF1 is reported. Calcitonin serum level after pentagastin was elevated (286 pg/ml). Genetic testing was performed in order to rule out mutations in the RET proto-oncogene. RESULT: No germline mutation previously reported in MEN2 was detected. Multifocal and bilateral CCH was demonstrated by immunohistochemistry. CONCLUSION: It is suggested that in such a genetic background of high risk for malignancy, CCH could be considered as an extremely rare condition likely preceding MTC. Copyright 2002 S. Karger AG, Basel Publication Types: Case Reports PMID: 11815730 [PubMed - indexed for MEDLINE] DR137: J Clin Endocrinol Metab. 2002 Jan;87(1):393-7. Atypical MEN type 2B associated with two germline RET mutations on the same allele not involving codon 918. Menko FH, van der Luijt RB, de Valk IA, Toorians AW, Sepers JM, van Diest PJ, Lips CJ. Department of Clinical Genetics and Human Genetics, Vrije Universiteit Medical Center, 1007 MB Amsterdam, The Netherlands. fh.menko.humgen@med.vu.nl A kindred was diagnosed with atypical MEN type 2B characterized by medullary thyroid cancer and mucosal neurilemmomas in multiple family members. Mutation analysis revealed a double RET germline mutation, Val804Met and Ser904Cys, in affected individuals. The clinical phenotype, the functional effect of the mutations, and the clinical implications of our findings are discussed. PMID: 11788682 [PubMed - indexed for MEDLINE] NR138: Horm Res. 2001;56 Suppl 1:67-72. Multiple endocrine neoplasia. Thakker RV. Molecular Endocrinology Group, Nuffield Department of Clinical Medicine, University of Oxford, John Radcliffe Hospital, Headington, Oxford OX3 9DU, UK. rakesh.thakker@ndm.ox.ac.uk Multiple endocrine neoplasia (MEN) is characterized by the occurrence of tumours involving two or more endocrine glands; two major forms, referred to as MEN1 and MEN2, are recognized. MEN1 is characterized by parathyroid, pancreatic islet and anterior pituitary tumours, whilst MEN2 is characterized by medullary thyroid carcinoma (MTC) in association with phaeochromocytoma. There are three clinical variants, referred to as MEN2A, MEN2B and MTC-only. All these forms of MEN may be inherited as autosomal dominant syndromes. The MEN1 gene is on chromosome 11q13 and about 300 MEN1 mutations have been identified. These are of diverse types and are scattered throughout the coding region. There is also a lack of genotype-phenotype correlation. All these findings make it difficult to implement MEN1 mutational analysis in the clinical setting. The situation in MEN2 is more straightforward. The gene causing all three MEN2 variants is located on chromosome 10cen-10q11.2, and is the c-ret proto-oncogene which encodes a tyrosine kinase receptor with cadherin-like and cysteine-rich extracellular domains, and a tyrosine kinase intracellular domain. Specific mutations of c-ret have been identified for each of the three MEN2 variants and mutational analysis has been used in the diagnosis and management of patients and families with the MEN2 variants. Copyright 2001 S. Karger AG, Basel Publication Types: Review Review, Tutorial PMID: 11786689 [PubMed - indexed for MEDLINE] DR139: Pediatr Dev Pathol. 2001 Sep-Oct;4(5):446-53. RET(Men2B)-transgene produces sympathoadrenal tumors but does not prevent intestinal aganglionosis in gdnf-/- or gfr alpha-1(-/-) mice. Rajan I, Gestblom C, Kapur RP. Department of Pathology, University of Washington, Seattle 98195, USA. Multiple endocrine neoplasia type 2B (MEN2B) syndrome is caused by a missense mutation in the RET gene, which replaces Met918 by Thr in the intracellular kinase domain of the protein. This single amino acid substitution transforms the receptor into a constitutively active monomeric kinase (RET(Men2B)) and produces an autosomal dominant syndrome characterized by medullary thyroid carcinoma, pheochromocytomas, musculoskeletal anomalies, and mucosal ganglioneuromas. The ligand, GDNF, stimulates RET activity through a co-receptor, GFR alpha-1. In vitro studies have shown that the kinase and mitogenic properties of RET(Men2B) are enhanced by GDNF/GFR alpha-1 stimulation. A relevant clinical question is whether ablation of either GDNF or GFR alpha-1 could alter penetrance or severity of the MEN2B syndrome. We report that ganglioneuromatous tumors caused by a RET(Men2B) transgene in mice are not affected grossly or microscopically by the absence of gdnf or gfr alpha-1. Loss-of-function mutations in ret, gdnf, or gfr alpha-1 cause pan-intestinal aganglionosis in mice. We find that expression of the RET(Men2B) transgene in enteric neural progenitors, after they colonize the gut, does not prevent intestinal aganglionosis associated with gdnf or gfr alpha-1 deficiency. PMID: 11779046 [PubMed - indexed for MEDLINE] DR140: Ann Oncol. 2001 Oct;12(10):1461-5. Quality of life in patients at risk of medullary thyroid carcinoma and followed by a comprehensive medical network: trends for future evaluations. Freyer G, Ligneau B, Schlumberger M, Blandy C, Contedevolx B, Trillet-Lenoir V, Lenoir GM, Chau N, Dazord A. Medical Oncology Unit, Centre Hospitalier Lyon-Sud, and EA 643, Universite Lyon I, France. Gilles.Freyer@chu-lyon.fr BACKGROUND: As shown in a previous study, the knowledge of the genetic risk in individuals belonging to families at risk of medullary-thyroid carcinoma (MTC) could be associated with impaired quality of life (QoL). PATIENTS AND METHODS: In the present study, we compared the QoL scores obtained in the same period with the subjective quality of life profile (SQLP): in 82 individuals at risk of MTC who had been tested for Ret-mutations; in 200 women at risk of familial breast/ovarian cancer syndrome (BOC); and in a control population of 3,501 healthy volunteers. RESULTS: Significant differences were observed in favour of healthy volunteers as well as individuals at risk of MTC, over women at risk of BOC (mean scores: 0.89, 0.85, and 0.64, respectively, P < or = 0.001), but QoL scores were not statistically different between individuals at risk of MTC and the control population (P = 0.2). However, they were significantly inferior in the subgroup of germline Ret-mutation carriers, as compared to the control population (mean scores: 0.73 and 0.89, P = 0.04). In the latter, the relationships with the children and the family were the most important facets of their QoL. CONCLUSION: Our results confirm the potentially negative impact of the knowledge of the genetic risk of cancer and its consequences in terms of morbidity and follow-up, on the QoL in people followed at oncogenetic visits. PMID: 11762820 [PubMed - indexed for MEDLINE] DR141: Ned Tijdschr Geneeskd. 2001 Nov 17;145(46):2217-21. Comment in: Ned Tijdschr Geneeskd. 2001 Nov 17;145(46):2234-41. [From gene to disease; from the RET gene to multiple endocrine neoplasia types 2A and 2B, sporadic and familial medullary thyroid carcinoma, Hirschsprung disease and papillary thyroid carcinoma] [Article in Dutch] Hofstra RM, van der Luijt RB, Lips CJ. Rijksuniversiteit, Disciplinegroep Medische Genetica, Groningen. The RET gene encodes a receptor tyrosine kinase involved in normal and neoplastic development of neural crest cell lineages. Activating RET mutations are present in patients with multiple endocrine neoplasia types 2A and 2B (MEN2A, 2B) and in familial medullary thyroid carcinoma (FMTC) patients, whereas inactivating RET mutations are found in patients with Hirschsprung (HSCR) disease. In particular for MEN2A and FMTC, the clinical management largely depends on the specific mutation found. Publication Types: Review Review, Tutorial PMID: 11757244 [PubMed - indexed for MEDLINE] DR142: Oncogene. 2001 Nov 22;20(53):7809-11. Allelic imbalance of the mutant and wild-type RET allele in MEN 2A-associated medullary thyroid carcinoma. Koch CA, Huang SC, Moley JF, Azumi N, Chrousos GP, Gagel RF, Zhuang Z, Pacak K, Vortmeyer AO. Pediatric and Reproductive Endocrinology Branch, National Institute of Child Health and Human Disease (NICHD), National Institutes of Health, Bethesda, Maryland 20892, USA. kochc@exchange.nih.gov Germline mutations of the RET proto-oncogene are responsible for the familial tumor syndrome called multiple endocrine neoplasia type 2 (MEN 2) that includes medullary thyroid carcinoma (MTC). Although inherited mutations of RET lead to tumor formation in patients with MEN 2, it is not understood why only selected cells develop into tumors. We have recently shown that duplication of the mutated RET allele or loss of the wild-type allele might represent mechanisms of tumorigenesis in patients with MEN 2A-related pheochromocytoma. We now analysed 19 DNA samples of MTC (15 of which were non-microdissected, four of which were microdissected) from patients with MEN 2A. Using polymorphic marker and phosphorimage densitometry analyses, we found allelic imbalance of the mutated and wild-type RET allele in six of 19 DNA MTC samples. Of note, two of the four microdissected tumor DNA samples showed allelic imbalance of RET, whereas only four of the 15 non-microdissected MTC samples did. These results underscore the significance of microdissection in the analysis of tumor DNA. In our study, some of the non-microdissected tumor DNA samples may have failed to display allelic imbalance of RET, because of contamination of tumor DNA with nonneoplastic DNA or noninformative microsatellite marker analysis. Taken together, our results suggest allelic imbalance between mutated and wild-type RET as a possible mechanism for tumor formation in some patients with MEN 2A-related MTC. PMID: 11753660 [PubMed - indexed for MEDLINE] DR143: Genes Chromosomes Cancer. 2001 Dec;32(4):390-1. Novel germline RET mutation segregating with papillary thyroid carcinomas. Rey JM, Brouillet JP, Fonteneau-Allaire J, Boneu A, Bastie D, Maudelonde T, Pujol P. Laboratoire de Biologie Cellulaire et Hormonale, Hopital A. de Villeneuve, CHU de Montpellier, Montpellier, France. The RET proto-oncogene is responsible for inherited medullary thyroid cancer syndromes. RET is also found mutated in sporadic medullary thyroid cancer (MTC) and rearranged in sporadic papillary thyroid carcinomas. Here, we describe a previously unreported germline RET mutation at codon 603 in exon 10 associated with both MTC and nonmedullary thyroid cancer (NMTC) in a kindred. RET may thus not be excluded as a potential candidate for predisposition to some forms of NMTC. Copyright 2001 Wiley-Liss, Inc. PMID: 11746981 [PubMed - indexed for MEDLINE] DR144: Lab Invest. 2001 Dec;81(12):1639-45. Frequent RET rearrangements in thyroid papillary microcarcinoma detected by interphase fluorescence in situ hybridization. Corvi R, Martinez-Alfaro M, Harach HR, Zini M, Papotti M, Romeo G. European Center for the Validation of Alternative Methods (RC), Institute for Health and Consumer Protection, Ispra, Italy. corvi@iarc.fr Papillary thyroid microcarcinomas (measuring 1 cm or less in diameter) are very common thyroid tumors, which are present in 10% to 35% of post-mortem histopathological examinations of individuals whose death was due to a cause other than thyroid cancer. The molecular basis of this tumor is still poorly understood. Somatic mutations are better characterized in clinically evident papillary thyroid carcinomas (PTCs), the most common involving the proto-oncogene RET, which maps to 10q11.2. Molecular alterations of RET always lead to intra- or interchromosomal rearrangements. In this study we have investigated the status of RET in 21 microcarcinomas, by means of interphase fluorescence in situ hybridization (FISH). RET was rearranged in 52% of microcarcinomas, a statistically significant higher frequency than that found previously in clinically evident PTCs using the same technique. Moreover, interphase FISH allowed us to detect a putative novel type of rearrangement in a microcarcinoma, and we observed trisomies of chromosome 10 and other chromosomes in two adenomas surrounding two of the microcarcinomas. The strikingly high frequency of RET rearrangements in microcarcinomas strongly suggests that RET plays a role in the initiation of thyroid tumorigenesis but does not seem to be necessary for the further progression of the tumor. PMID: 11742034 [PubMed - indexed for MEDLINE] DR145: J Med Genet. 2001 Nov;38(11):784-7. Familial medullary thyroid carcinoma and prominent corneal nerves associated with the germline V804M and V778I mutations on the same allele of RET. Kasprzak L, Nolet S, Gaboury L, Pavia C, Villabona C, Rivera-Fillat F, Oriola J, Foulkes WD. Publication Types: Case Reports Letter PMID: 11732489 [PubMed - indexed for MEDLINE] DR146: Endocrine. 2001 Jul;15(2):143-6. A case of multiple endocrine neoplasia type 2B undiagnosed for many years despite its typical phenotype. Ohyama T, Sato M, Murao K, Kittaka K, Namihira H, Matsubara S, Imachi H, Yamauchi K, Takahara J. First Department of Internal Medicine, Kagawa Medical University, Japan. toohyam@attglobal.net We report the case of a 24-yr-old man with a typical phenotype of multiple endocrine neoplasia type 2B (MEN 2B). The patient had previously undergone minor surgery to remove multiple tumors on the lip, but he had no further examinations. MEN 2B was suspected owing to characteristic multiple ganglioneuromatosis when the patient presented with a goiter associated with high levels of plasma calcitonin and CEA. Aspiration biopsy cytology revealed medullary thyroid carcinoma (MTC), and abdominal computed tomography and nuclear scanning with metaiodobenzylguanidine revealed bilateral adrenomedullary tumors. Adrenomedullary function tests showed high levels of serum and urinary fractionated catecholamines, and genetic analysis showed a point mutation in the codon 918 (M918T) of the RET gene. The patient was diagnosed with MEN 2B and underwent right adrenalectomy and total thyroidectomy. No distant metastasis of the MTC was noted although MEN 2B had remained undiagnosed since the ganglioneuromatosis was first noticed. MEN 2B is a rare hereditary disorder, but the occurrence of characteristic ganglioneuromatosis was quite helpful in making the diagnosis. Publication Types: Case Reports PMID: 11720239 [PubMed - indexed for MEDLINE] NR147: Tumori. 2001 Jul-Aug;87(4):S49-51. Surgical treatment of medullary carcinoma of the thyroid. Favia G, Lumachi F. Department of Surgical and Gastroenterological Sciences, University of Padua, School of Medicine, Italy. PMID: 11693822 [PubMed - indexed for MEDLINE] DR148: J Mol Med. 2001 Oct;79(10):609-12. Three novel mutations in the RET proto-oncogene. Kalinin VN, Amosenko FA, Shabanov MA, Lubchenko LN, Hosch SB, Garkavtseva RF, Izbicki JR. Research Laboratory, Department for General Surgery, Hamburg University Hospital Eppendorf, Martinistrasse 52, 20251 Hamburg, Germany. kalinin@uke.uni-hamburg.de Medullary thyroid carcinoma (MTC) occurs as a sporadic tumor or in connection with inherited cancer syndromes of multiple endocrine neoplasia type 2 and familial MTC. Missense RET proto-oncogene mutations and small in-frame deletions are found in most of the cases. In a significant amount of sporadic MTC cases somatic mutation at codon 918 (exon 16), or at codons 609, 611, 618, 620 (exon 10), or codons 630, 634 (exon 11) appear. We report here on three new somatic cell missense mutations of the RET proto-oncogene associated with sporadic MTC. In one tumor mutation at codon 922 TCC(Ser)-->TTC(Phe) in exon 16 was found. In another tumor two mutations at codons 639 GCA(Ala)-->GGA(Gly) and 641 GCT(Ala)-->CGT(Arg) in the exon 11 were observed. Allele-specific PCR followed by sequencing demonstrated the presence of both mutations at the same allele. PMID: 11692159 [PubMed - indexed for MEDLINE] NR149: Am J Surg Pathol. 2001 Oct;25(10):1245-51. Comment in: Am J Surg Pathol. 2003 Feb;27(2):266-7. Comment on: Am J Surg Pathol. 2003 Jan;27(1):136; author reply 136-7. Sporadic versus familial medullary thyroid microcarcinoma: a histopathologic study of 50 consecutive patients. Kaserer K, Scheuba C, Neuhold N, Weinhausel A, Haas OA, Vierhapper H, Niederle B. Department of Clinical Pathology, University of Vienna, Medical School, Austria. k.kaserer@akh-wien.ac.at By means of calcitonin screening programs, sporadic and hereditary medullary thyroid carcinoma (MTC) can be detected at an early stage. We investigated the histopathologic findings of 16 familial (mean age 32 +/- 21 years, female/male ratio 1.6:1) and 34 sporadic (mean age 58 +/- 15 years; female/male ratio 2.4:1) MTCs with stage T1 comparatively. Patients with hereditary tumors were younger. Hereditary tumors were more often found multifocal (13 of 16 vs 3 of 34; p < 0.001), bilateral (11 of 16 vs 3 of 34; p < 0.001), displaying desmoplastic stroma (14 of 16 vs 19 of 34; p = 0.02), and accompanied by C cell hyperplasia (16 of 16 vs 24 of 34; p = 0.01), but all of these factors were present in some sporadic patients. Only tumors with desmoplastic stroma showed lymph node metastasis, which was observed in eight of the 50 patients. After surgery all patients showed permanent normalization of calcitonin levels. We conclude that 1) morphologic parameters considered to indicate familial MTC risk are of no value in the individual patient, 2) many sporadic MTCs develop on the background of CCH, 3) tumors with desmoplastic stroma are more likely to develop lymph node metastasis, and 4) early detection of MTC permits curative surgery in the majority of patients. Publication Types: Comment PMID: 11688458 [PubMed - indexed for MEDLINE] DR150: Clin Endocrinol (Oxf). 2001 Oct;55(4):543-8. A novel chromosomal translocation t(3;5)(q12;p15.3) and loss of heterozygosity on chromosome 22 in a multifocal follicular variant of papillary thyroid carcinoma presenting with skin metastases. Smit JW, Van Zelderen-Bhola S, Merx R, De Leeuw W, Wessels H, Vink R, Morreau H. Department of Endocrinology, Leiden University Medical Center, Leiden, The Netherlands. j.w.a.smit.endo@lumc.nl Classic genetic rearrangements in papillary carcinoma of the thyroid involve the RET- or TRK proto-oncogenes. We report a novel chromosomal translocation t(3;5)(q12;p15.3), confirmed by fluorescence in situ hybridization, in a multifocal follicular variant of a papillary carcinoma of the thyroid in a 79-year-old woman, with skin metastases as a presenting symptom. Three years earlier, another cutaneous metastasis on her scalp was misdiagnosed as hidradenoma. Four tumour foci were recognized in the thyroid, two with a follicular variant of papillary carcinoma. To detect loss of heterozygosity, 14 chromosomes were investigated with 59 microsatellite markers. A clonal relationship was detected between the two foci of tumour in the thyroid gland containing follicular variant of papillary carcinoma and one of the skin lesions tested, all demonstrating loss of heterozygosity (LOH) in the same region of chromosome 22. Based on earlier reports, the low rate of LOH detected is in agreement with the diagnosis papillary carcinoma of the thyroid. Whole body scintigraphy performed after ablative therapy with radioiodine revealed multiple metastases in the lungs and skeleton. After repeated radioiodine therapy, thyroglobulin under thyroxine suppression became undetectable and post-therapeutic scintigraphy revealed important regression of metastases. Publication Types: Case Reports PMID: 11678839 [PubMed - indexed for MEDLINE] NR151: Clin Chem. 2001 Nov;47(11):1939-44. Novel technique for scanning of codon 634 of the RET protooncogene with fluorescence resonance energy transfer and real-time PCR in patients with medullary thyroid carcinoma. Ruiz A, Antinolo G, Marcos I, Borrego S. Unidad de Genetica Medica y Diagnostico Prenatal Hospitales Universitarios Virgen del Rocio, 41013-Seville, Spain. BACKGROUND: The multiple endocrine neoplasia 2 (MEN 2) syndromes [MEN 2A, MEN 2B, and familial medullary thyroid carcinoma (FMTC)] are caused by germline mutations of the RET protooncogene. Because 85% of MEN 2A patients and 30% of FMTC patients have mutations at codon 634, the recommended molecular analyses begin at exon 11, where codon 634 is located. METHODS: We scanned codon 634 of the RET protooncogene with real-time PCR and fluorescence resonance energy transfer (FRET), using a unique pair of internal probes to detect mutations localized at codon 634. We compared results with sequencing results in 66 patients. RESULTS: The method detected all codon 634 mutations available in our laboratory (Cys634Tyr, Cys634Arg, Cys634Phe, Cys634Trp). Comparing this method with the direct sequencing of exon 11 in a cohort of 66 patients with MTC, the system identified all 14 MTC patients carrying germline mutations at codon 634. One apparent false-positive result occurred among 52 patients. CONCLUSIONS: The simultaneous scanning of multiple mutations is possible with the FRET system. The method allows rapid characterization of germline mutations at codon 634 in MTC patients. PMID: 11673360 [PubMed - indexed for MEDLINE] DR152: Clin Endocrinol (Oxf). 2001 Sep;55(3):399-402. Germline sequence variant S836S in the RET proto-oncogene is associated with low level predisposition to sporadic medullary thyroid carcinoma in the Spanish population. Ruiz A, Antinolo G, Fernandez RM, Eng C, Marcos I, Borrego S. Unidad de Genetica Medica y Diagnostico Prenatal, Hospitales Universitarios Virgen del Rocio, Sevilla, Spain. OBJECTIVE: The molecular basis of sporadic medullary thyroid carcinoma (MTC) remains elusive. While germline gain-of-function mutations in the RET proto-oncogene cause hereditary MTC, somatic activating RET mutations and loss of heterozygosity of markers in various chromosomal regions representing deletions of tumour suppressor genes, have been described in a variable number of sporadic MTC. A previous report suggested that the presence of a germline variant at RET codon 836 (S836S) was associated with the development of sporadic MTC and, furthermore, that the presence of S836S was highly correlated with somatic RET M918T mutation in the MTC. Thus, we sought to determine if the S836S variant would be associated with sporadic MTC from a completely different population base, that of Andalucia. DESIGN: This is a case-control study to determine whether the presence of RET germline S836S is correlated with sporadic MTC in Andalucia. PATIENTS: Thirty-two patients with sporadic MTC from the Andalucia region of Spain, serviced by our University Hospital, were ascertained throughout the period 1995-99. Sporadic MTC was defined as a lack of personal or family history suggestive of multiple endocrine neoplasia type 2 (MEN 2) and lack of germline RET mutations which define any MEN 2 subtype. A region and race matched cohort of 250 controls was also obtained. MEASUREMENTS: The frequency of the S836S allele was determined in cases and controls and compared using the standard chi-squared statistic and Fisher's exact test. RESULTS: The polymorphic allele frequency at codon 836 in the control population (18/500 chromosomes, 3.6%) differed significantly from the MTC case cohort, 9.3% of case chromosomes (six of 64 alleles, Fisher's exact test, two-tailed, P = 0.043). CONCLUSIONS: Germline RET S836S variant is associated with a two- to three-fold risk of sporadic MTC in the Spanish population, in accordance with a previous study based on German cases. Our observations suggest that this phenomenon might be universal and not limited to Germany. PMID: 11589684 [PubMed - indexed for MEDLINE] DR153: Trends Genet. 2001 Oct;17(10):580-9. The RET receptor: function in development and dysfunction in congenital malformation. Manie S, Santoro M, Fusco A, Billaud M. Laboratoire de Genetique, CNRS UMR 5641, Domaine Rockefeller, 8 avenue Rockefeller, 69373 Cedex 08, Lyon, France. Germline mutations in the RET proto-oncogene are responsible for two unrelated neural crest disorders: Hirschsprung disease, a congenital absence of the enteric nervous system in the hindgut, and multiple endocrine neoplasia type 2, a dominantly inherited cancer syndrome. Moreover, somatic rearrangements of RET are causally involved in the genesis of papillary thyroid carcinoma. The receptor tyrosine kinase encoded by the RET gene acts as the subunit of a multimolecular complex that binds four distinct ligands and activates a signalling network crucial for neural and kidney development. Over the past few years, a clearer picture of the mode of RET activation and of its multifaceted role during development has started to emerge. These findings, which provide new clues to the molecular mechanisms underlying RET signalling dysfunction in Hirschsprung disease, are summarized in this review. PMID: 11585664 [PubMed - indexed for MEDLINE] DR154: Lakartidningen. 2001 Aug 29;98(35):3690-1, 3694-5. [Phenotypic expression of a mutation in MEN 2A documented in a family in the western part of Sweden] [Article in Swedish] Lindskog S, Ahlman H, Illerskog A, Nilsson O, Nilsson B, Tisell LE, Ysander L, Jansson S. Kirurgiska kliniken, Sjukhuset i Varberg, Goteborg. A missense mutation at codon 618 of the RET proto-oncogene is a rather unusual cause of multiple endocrine neoplasia 2A. We report the phenotypic expression of this specific RET mutation in a large Swedish family. The family was mapped back to the 18th century. Since 1971 the family has been included in a biochemical screening program, and since 1994 has undergone genetic screening. Twenty-seven individuals were found to have medullary thyroid carcinoma (MTC). Eighteen were detected by screening. The incidence of pheochromocytoma (4%) and hyperparathyroidism (7%) was low. Five individuals died of MTC, but of these none had been included in the screening program. One patient underwent prophylactic thyroidectomy after positive genetic screening. MTC tumor aggressivity differed markedly between gene carriers. The screening program shows that the clinical aggressivity of MTC can be mitigated by early and adequate surgical intervention. PMID: 11577645 [PubMed - indexed for MEDLINE] DR155: Mol Cell Biol. 2001 Oct;21(20):6719-30. The sensitivity of activated Cys Ret mutants to glial cell line-derived neurotrophic factor is mandatory to rescue neuroectodermic cells from apoptosis. Mograbi B, Bocciardi R, Bourget I, Juhel T, Farahi-Far D, Romeo G, Ceccherini I, Rossi B. INSERM U 364, IFR50, Faculte de Medecine Pasteur, Nice, France. Hirschsprung's disease (HSCR), a frequent developmental defect of the enteric nervous system is due to loss-of-function mutations of RET, a receptor tyrosine kinase essential for the mediation of glial cell-derived neurotrophic factor (GDNF)-induced cell survival. Instead, gain-of-function Cys mutations (e.g., Cys(609), Cys(620), and Cys(634)) of the same gene are responsible for thyroid carcinoma (MEN2A/familial medullary thyroid carcinoma) by causing a covalent Ret dimerization, leading to ligand-independent activation of its tyrosine kinase. In this context, the association of Cys(609)- or Cys(620)-activating mutations with HSCR is still an unresolved paradox. To address this issue, we have compared these two mutants with the Cys(634) Ret variant, which has never been associated with HSCR, for their ability to rescue neuroectodermic cells (SK-N-MC cells) from apoptosis. We show here that despite their constitutively activated kinase, the mere expression of these three mutants does not allow cell rescue. Instead, we demonstrate that like the wild-type Ret, the Cys(634) Ret variant can trigger antiapoptotic pathways only in response to GDNF. In contrast, Cys(609) or Cys(620) mutations, which impair the terminal Ret glycosylation required for its insertion at the plasma membrane, abrogate GDNF-induced cell rescue. Taken together, these data support the idea that sensitivity to GDNF is the mandatory condition, even for constitutively activated Ret mutants, to rescue neuroectodermic cells from apoptosis. These findings may help clarify how a gain-of-function mutation can be associated with a developmental defect. PMID: 11564857 [PubMed - indexed for MEDLINE] DR156: Endocrinology. 2001 Oct;142(10):4441-7. Inhibition of Ret oncogene activity by the protein tyrosine phosphatase SHP1. Hennige AM, Lammers R, Hoppner W, Arlt D, Strack V, Teichmann R, Machicao F, Ullrich A, Haring HU, Kellerer M. Universitat Tubingen, Medizinische Klinik und Poliklinik IV, D-72076 Tubingen, Germany. Germline mutations in the Ret protooncogene give rise to the inherited endocrine cancer syndromes MEN types 2A and 2B and familiar medullary thyroid carcinoma. Although it is well accepted that the constitutive active tyrosine kinase of Ret oncogenes ultimately leads to malignant transformation, it is not clear whether a decrease in the autophosphorylation of oncogenic Ret forms can affect the mitogenic and transforming activities of Ret. Potential modulators of the tyrosine kinase activity of Ret could be tyrosine phosphatases that are expressed in human thyroid tissue. Therefore, we investigated the impact of the tyrosine phosphatases SHP1 and SHP2 on the intrinsic tyrosine kinase activity and oncogenic potency of Ret with a 9-bp duplication in the cysteine-rich domain (codons 634-636), which was described in a patient with MEN type 2A recently. SHP1 and SHP2 were stably overexpressed in NIH3T3 fibroblasts together with Ret-9bp. Coexpression of SHP1 with Ret-9bp reduced the autophosphorylation of Ret-9bp by 19 +/- 7% (P = 0.01, n = 4), whereas no effect was seen with SHP2. Furthermore, Ret-9bp could be coimmunoprecipitated with SHP1 but not with SHP2 antibodies. Suppression of the Ret-9bp tyrosine kinase activity by SHP1 caused a decrease in activation of Erk2 (extracellular signal-regulated kinase) and abolished PKB/Akt (protein kinase B) phosphorylation. In addition, diminished Ret-9bp autophosphorylation led to reduced phosphorylation of the transcription factor jun-D. Finally, the inhibitory effect on Ret-9bp signaling resulted in a 40-60% reduction of [(3)H]thymidine incorporation and in reduced ability of NIH3T3 cells to form colonies in soft agar. In conclusion, the data suggest that SHP1 caused a moderate reduction of Ret autophosphorylation, which led to a strong suppression of the Ret oncogene activity. PMID: 11564708 [PubMed - indexed for MEDLINE] DR157: Rev Med Chil. 2001 Jul;129(7):713-8. [Germline mutations of the ret proto-oncogene in Chilean patients with hereditary and sporadic medullary thyroid carcinoma] [Article in Spanish] Wohllk N, Becker P, Youlton R, Cote GJ, Gagel RF. Seccion de Endocrinologia, Departamento de Medicina, Hospital del Salvador, Laboratorio IEMA, Santiago de Chile. iema@terra.cl BACKGROUND: Medullary thyroid carcinoma (MTC) may occur either as a sporadic or familial disease. Multiple endocrine neoplasia (MEN) type 2, inherited as an autosomal dominant disease, is characterized by MTC only (FMTC) or coexistence of MTC with other endocrine neoplasia (NEM 2A, 2B). Germline mutations of the RET proto-oncogene (cRet) are found in the inherited forms and in some apparently sporadic MTC cases. AIM: To study RET mutations in 8 families with MEN 2. MATERIAL AND METHODS: RET mutations were screened in peripheral blood DNA from 18 patients and 87 high risk carriers belonging to 8 MEN 2 families and 52 sporadic MTC. Exons 10, 11, 13, 14, 15 and 16 of the c-Ret were amplified by polymerase chain reaction (PCR) and examined by direct sequencing of PCR products and/or restriction enzyme analysis. RESULTS: Five MEN 2A and one FMTC families with a germline mutation at codon 634, one MEN 2A and one FMTC family carrying a mutation at codon 620 were identified. Mutations were found in 23 out of 87 high risk carriers. In addition, we detected a S891A (exon 15) germline mutation in a sporadic MTC patient and in one out of her three sons and V804M (exon 14) in another sporadic MTC case and in one out of his six relatives, indicating in both cases the presence of a sporadic misclassified familial disease. CONCLUSIONS: These results underscore the importance of routine application of c-Ret testing in all cases of MTC either familial or sporadic. PMID: 11552438 [PubMed - indexed for MEDLINE] NR158: Cytokine Growth Factor Rev. 2001 Dec;12(4):361-73. The GDNF/RET signaling pathway and human diseases. Takahashi M. Department of Pathology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan. mtakaha@med.nagoya-u.ac.jp Glial cell line-derived neurotrophic factor (GDNF) and related molecules, neurturin, artemin and persephin, signal through a unique multicomponent receptor system consisting of RET tyrosine kinase and glycosyl-phosphatidylinositol-anchored coreceptor (GFRalpha1-4). These neurotrophic factors promote the survival of various neurons including peripheral autonomic and sensory neurons as well as central motor and dopamine neurons, and have been expected as therapeutic agents for neurodegenerative diseases. In addition, it turned out that the GDNF/RET signaling plays a crucial role in renal development and regulation of spermatogonia differentiation. RET mutations cause several human diseases such as papillary thyroid carcinoma, multiple endocrine neoplasia types 2A and 2B, and Hirschsprung's disease. The mutations resulted in RET activation or inactivation by various mechanisms and the biological properties of mutant proteins appeared to be correlated with disease phenotypes. The signaling pathways activated by GDNF or mutant RET are being extensively investigated to understand the molecular mechanisms of disease development and the physiological roles of the GDNF family ligands. Publication Types: Review Review, Tutorial PMID: 11544105 [PubMed - indexed for MEDLINE] DR159: J Endocrinol. 2001 Sep;170(3):661-6. Molecular genetic diagnostic program of multiple endocrine neoplasia type 2A and familial medullary thyroid carcinoma syndromes in Hungary. Klein I, Esik O, Homolya V, Szeri F, Varadi A. Institute of Enzymology of the Hungarian Academy of Sciences, Budapest, Hungary. klein@enzim.hu Medullary thyroid carcinoma (MTC) occurs usually in sporadic form, but about a quarter of the cases are hereditary and appear as part of one of the multiple endocrine neoplasia type 2 (MEN2) syndromes. Mutations in the RET protooncogene are known to be the cause of the MEN2A and familial medullary thyroid carcinoma (FMTC) syndromes in the majority of the families. Direct DNA testing allows prophylactic thyroidectomy to be offered to individuals carrying a mutation in the above codons, and in mutation-negative cases it reduces the yearly screening-related burden on family members at risk of the disease. By DNA sequencing and PCR-restriction fragment length polymorphisms, 65 MTC probands were examined for mutations in residues 609, 611, 618, 620 of exon 10, and in residues 634, 768, 804 of exons 11, 13, and 14 respectively of the RET protooncogene. In our study, mutations in the above codons were detected in all of the 14 clinically MEN2A and FMTC families. One of these mutations, TGC609 TCC has not been reported previously. Of the 14 probands with the mutation, 25 relatives also had the identified mutation and 18 relatives proved to be non-carriers. Among the 51 probands with clinically sporadic MTC, none was found to carry a mutation in the above positions even if indirect signs of MTC, pheochromocytoma or hyperparathyroidism could be detected in some families. The frequency of the TGC634AGC mutation is unexpectedly high in our samples, which can probably be attributed to a founder effect. We conclude that screening for mutations in these codons is effective in families fulfilling the strict clinical criteria of MEN2A or FMTC. PMID: 11524247 [PubMed - indexed for MEDLINE] PR160: J Clin Endocrinol Metab. 2001 Aug;86(8):3948-57. Germline RET 634 mutation positive MEN 2A-related C-cell hyperplasias have genetic features consistent with intraepithelial neoplasia. Diaz-Cano SJ, de Miguel M, Blanes A, Tashjian R, Wolfe HJ. Department of Pathology, Tufts University-New England Medical Center, Boston, Massachusetts 02111, USA. s.j.diaz-cano@mds.qmw.ac.uk C-cell hyperplasias are normally multifocal in multiple endocrine neoplasia type 2A. We compared clonality, microsatellite pattern of tumor suppressor genes, and cellular kinetics of C-cell hyperplasia foci in each thyroid lobe. We selected 11 females from multiple endocrine neoplasia type 2A kindred treated with thyroidectomy due to hypercalcitoninemia. C-cell hyperplasia foci were microdissected for DNA extraction to analyze the methylation pattern of androgen receptor alleles and microsatellite regions (TP53, RB1, WT1, and NF1). Consecutive sections were selected for MIB-1, pRB1, p53, Mdm-2, and p21WAF1 immunostaining, DNA content analysis, and in situ end labeling. Appropriate tissue controls were run. Only two patients had medullary thyroid carcinoma foci. Nine informative C-cell hyperplasia patients showed germline point mutation in RET, eight of them with the same androgen receptor allele preferentially methylated in both lobes. C-cell hyperplasia foci showed heterogeneous DNA deletions revealed by loss of heterozygosity of TP53 (12 of 20), RB1 (6 of 14), and WT1 (4 of 20) and hypodiploid G0/G1 cells (14 of 20), low cellular turnover (MIB-1 index 4.5%, in situ end labeling index 0.03%), and significantly high nuclear area to DNA index ratio. MEN 2A (germline point mutation in RET codon 634) C-cell hyperplasias are monoclonal and genetically heterogeneous and show down-regulated apoptosis, findings consistent with an intraepithelial neoplasia. Concordant X-chromosome inactivation and interstitial gene deletions suggest clone expansions of precursors occurring at a point in embryonic development before divergence of each thyroid lobe and may represent a paradigm for other germline mutations. PMID: 11502837 [PubMed - indexed for MEDLINE] DR161: J Clin Endocrinol Metab. 2001 Aug;86(8):3746-53. Familial medullary thyroid carcinoma with noncysteine ret mutations: phenotype-genotype relationship in a large series of patients. Niccoli-Sire P, Murat A, Rohmer V, Franc S, Chabrier G, Baldet L, Maes B, Savagner F, Giraud S, Bezieau S, Kottler ML, Morange S, Conte-Devolx B; French Calcitonin Tumors Group (GETC). Service d'Endocrinologie, CHU Timone, 13385 Marseilles, France. pniccoli-sire@ap-hm.fr Familial medullary thyroid carcinoma only is related to germline mutations in the protooncogene RET, mainly in exons 10, whereas noncysteine mutations (exons 13-15) are considered infrequent. We analyzed 148 patients from 47 familial medullary thyroid carcinoma only families, and we found noncysteine RET mutations in 59.5% of these families. Of the index cases with noncysteine mutations, 43.4% presented with a multinodular goiter and high basal calcitonin; they were older at diagnosis than those with mutation in exon 10 and had more multifocal medullary thyroid carcinoma, but no difference in size, bilaterality, presence of C cell hyperplasia, or nodal metastases was found. Gene carriers with noncysteine RET mutations had a lower incidence of medullary thyroid carcinoma (78.2% vs. 94.1%) than those with mutation in exon 10; 20.2% had C cell hyperplasia only, although thyroidectomized at an older age. In conclusion, familial medullary thyroid carcinoma with noncysteine RET mutations are not infrequent and are overrepresented in presumed sporadic medullary thyroid carcinoma, suggesting that RET analysis should routinely be extended to exons 13, 14, and 15. The phenotype is characterized by a late onset of the disease, suggesting a delayed appearance of C cell disease rather than a less aggressive form. In familial medullary thyroid carcinoma gene carriers, the optimal timing for thyroidectomy remains controversial. Based on these data, we propose that surgery should be performed before elevation of the basal calcitonin level, potentially as soon as the pentagastrin test becomes abnormal. Publication Types: Multicenter Study PMID: 11502806 [PubMed - indexed for MEDLINE] DR162: Oncogene. 2001 Jul 5;20(30):3986-94. C-cell and thyroid epithelial tumours and altered follicular development in transgenic mice expressing the long isoform of MEN 2A RET. Reynolds L, Jones K, Winton DJ, Cranston A, Houghton C, Howard L, Ponder BA, Smith DP. CRC Department of Oncology, University of Cambridge, Cambridge Institute for Medical Research, Wellcome Trust/MRC Building, Hills Road, Cambridge CB2 2XY, UK. Gain-of-function mutations in the gene encoding the receptor tyrosine kinase RET have been identified as the aetiological factor for multiple endocrine neoplasia type 2A (MEN2A). MEN2A is a dominantly-inherited cancer predisposition syndrome characterized by medullary thyroid carcinoma, a tumour of the calcitonin-producing thyroid C-cells. There are three isoforms of RET: RET9, RET43 and RET51, and although in vitro evidence suggests they vary in cellular transformation activities, little is known about their function in tumorigenesis in vivo. To address this, we used RET51 cDNA to construct mice in which the most frequent MEN2A mutation, Cys-634-Arg, was expressed under the control of the human calcitonin promoter (CT-2A mice). These mice developed C-cell tumours resembling human MTC and follicular tumours resembling human papillary thyroid carcinoma (PTC) depending on the founder line examined. One founder line developed compound MTC/PTC at low frequency (8%) and pancreatic cystadenocarcinoma. CT-2A mice also displayed a developmental defect in thyroid follicular structure, in which much of the thyroid was occupied by large irregular cystic follicles thought to be derived from the ultimobranchial body, a developmental precursor of the thyroid gland. The CT-2A mice will provide a suitable model to further study the effects of the MEN 2A RET mutation in vivo. PMID: 11494127 [PubMed - indexed for MEDLINE] NR163: Graefes Arch Clin Exp Ophthalmol. 2001 Jun;239(5):391-4. Typical ocular findings in a patient with multiple endocrine neoplasia type 2b syndrome. Eter N, Klingmuller D, Hoppner W, Spitznas M. Department of Ophthalmology, Bonn University Medical Center, Germany. eter@uni-bonn.de BACKGROUND: Multiple endocrine neoplasia (MEN) type 2b syndrome is accompanied by typical ocular findings; however, the disease is often only diagnosed at an advanced stage by symptoms of C-cell carcinoma or pheochromocytoma and is then fatal in most cases. Therefore, the importance of ophthalmic assessment in making the diagnosis has to be stressed. METHODS: The history and ocular findings of a patient with MEN 2b syndrome are described, and a brief overview of the syndrome is given. RESULTS: Slit-lamp examination showed extremely thickened corneal nerves as well as multiple small plexiform and nodular subconjunctival tumors. Both eyes also displayed thickened upper and lower eyelids. A molecular genetic study of the RET proto-oncogene showed a heterozygous ATG to ACG mutation in codon 918 of exon 16. CONCLUSION: Greatly thickened corneal nerves and subconjunctival tumors may be the first hint of MEN 2b. Whenever greatly thickened corneal nerves are detected, MEN 2b must be ruled out. Publication Types: Case Reports PMID: 11482345 [PubMed - indexed for MEDLINE] PR164: Eur J Surg. 2001 Jun;167(6):467-9. Total thyroidectomy for hereditary medullary thyroid carcinoma 12 years after correction of Hirschsprung's disease. Sasaki Y, Shimotake T, Go S, Iwai N. Division of Surgery, Children's Research Hospital, Kyoto Prefectural University of Medicine, Japan. Publication Types: Case Reports PMID: 11471675 [PubMed - indexed for MEDLINE] DR165: Curr Drug Targets. 2001 Mar;2(1):41-55. Receptor tyrosine kinases as therapeutic targets: the model of the MET oncogene. Longati P, Comoglio PM, Bardelli A. Institute for Cancer Research, University of Torino Medical School, Candiolo, Italy. Control of cell growth and differentiation occurs via extracellular signals known as growth factors. Growth factors are high affinity ligands for transmembrane receptors belonging to the family of receptor tyrosine kinases (RTKs). A number of genetic evidences have implicated RTKs in human diseases including developmental disorders and cancer. For instance, germline missense mutations involving the Ret receptor are found in patients affected by multiple endocrine neoplasia types 2A and 2B (MEN2A and MEN2B) or familial medullary thyroid carcinomas. Somatic mutations in the Kit receptor are found in mastocytomas and in gastrointestinal tumors. Germline and sporadic mutations of the Met receptor have been described in kidney and hepatocellular carcinomas. Overexpression of the HER-2/neu receptor in breast cancer has been associated with tumor progression. The enzymatic activity of RTKs is strictly regulated and is usually inhibited under basal conditions. Receptor activation triggers a biochemical signalling cascade inside the cytoplasm, named signal transduction, which is subverted during the malignant transformation of cells. Signal transduction by RTKs is a multistep process which includes: (i) Ligand binding and receptor dimerization, (ii) receptor phosphorylation on tyrosine residues; (iii) recruitment to the receptor and activation of cytoplasmic signaling molecules that transmit signals to the nucleus. Each of the steps involved in this process can potentially be targeted to block the aberrant properties of tyrosine kinase receptors. By using the MET oncogene as a model this review focuses on the strategies that can be applied to therapeutically target RTKs. Publication Types: Review PMID: 11465538 [PubMed - indexed for MEDLINE] DR166: Lakartidningen. 2001 Jun 20;98(25):3024-8. [Hereditary thyroid cancer can be cured by prophylactic surgery] [Article in Swedish] Wallin G, Bondesson AG, Farnebo LO, Hallengren B, Hamberger B, Jansson S, Nilsson O, Nordenskjold M, Smeds S, Svensson KA, Wihlborg O, Zedenius J. Kirurgiska kliniken, Karolinska sjukhuset, Stockholm. Multiple endocrine neoplasia type 2 (MEN 2) is a rare syndrome in which the consequences for the patient and family members are considerable. Mutation analysis of the RET proto-oncogene is crucial for decision-making regarding each patient. Today, carriers of MEN 2 mutations should be offered prophylactic thyroidectomy with the potential to eliminate the risk for potentially lethal medullary thyroid carcinoma (MTC). Here, we present the first Swedish experience of such operations performed mainly on the basis of genetic analysis. Twenty patients underwent total thyroidectomy at a mean age of 13.5 (6-43) years. In all cases, either manifest MTC (n = 11) or C-cell hyperplasia was found. So far, no patient has any sign of recurrence or developmental insufficiency at 1-5 years follow-up. As the medical and ethical problems in this group of patients are substantial, and as the operations are performed in otherwise healthy children, they should be treated at centers with adequate multidisciplinary expertise and competence. Publication Types: Case Reports PMID: 11462876 [PubMed - indexed for MEDLINE] DR167: J Intern Med. 2001 Jul;250(1):37-42. Multiple endocrine neoplasia type 2 syndromes may be associated with renal malformations. Lore F, Talidis F, Di Cairano G, Renieri A. Endocrinology Unit, University of Siena, Italy. lore@unisi.it OBJECTIVE: The RET proto-oncogene is known to be the susceptibility gene for various disease phenotypes, including multiple endocrine neoplasia type 2 (MEN 2). Recent studies have also suggested an involvement of RET in the development of the mammalian kidney. Although kidney agenesis or dysgenesis has been observed in mice lacking functional ret, no clinically relevant kidney abnormalities have been reported in individuals with known RET mutations and familial medullary thyroid carcinoma (FMTC). We have studied a family with five members affected with isolated FMTC. DNA analysis was performed and the involved RET mutation was identified. Amongst these patients were a woman and her son. DESIGN: Case report. SETTING: University department. PATIENTS: A 32-year-old woman and her son with FMTC and unilateral renal agenesis. RESULTS: The woman's abdominal ultrasound findings demonstrated unilateral renal absence of the left kidney. Her son, when only a few months old, had undergone surgical treatment for Hirschsprung's disease. Abdominal ultrasonography was performed recently, and left-side renal absence was diagnosed. Intravenous pyelography confirmed the agenesis of his left kidney, whilst the contralateral kidney displayed compensatory hypertrophy. CONCLUSIONS: The involvement of the RET proto-oncogene in the early growth and differentiation of the human kidney is now generally accepted. We believe that at least a proportion of patients with MEN 2 may have undiagnosed renal malformations. We suggest therefore that noninvasive imaging techniques, such as ultrasonography, should be used to explore the presence of renal abnormalities in subjects with demonstrated RET mutations. Publication Types: Case Reports Review Review of Reported Cases PMID: 11454140 [PubMed - indexed for MEDLINE] DR168: Endocrinol Metab Clin North Am. 2001 Jun;30(2):493-513, x. Genetic markers in thyroid neoplasia. Puxeddu E, Fagin JA. Division of Endocrinology and Metabolism, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA. Cancer is a disease of genes. Detection of genetic abnormalities associated with cancers of various cell types can now be used for genetic counseling, diagnosis or treatment selection. In the case of thyroid cancer, genetic testing for mutations of the RET oncogene has had a profound effect on the management of medullary thyroid carcinomas. There is also considerable information on the genetic changes associated with development and progression of cancers of thyroid follicular cells, although these have not yet proven to be of practical value for clinical diagnosis or to guide prognosis and therapy. Publication Types: Review Review, Tutorial PMID: 11444172 [PubMed - indexed for MEDLINE] PR169: Front Horm Res. 2001;28:81-102. Multiple endocrine neoplasia type 2: molecular aspects. Mulligan LM. Department of Paediatrics, Queen's University, Kingston, Ont., Canada. mulligal@post.queensu.ca Publication Types: Review PMID: 11443855 [PubMed - indexed for MEDLINE] PR170: Front Horm Res. 2001;28:103-30. Multiple endocrine neoplasia type 2: clinical aspects. Gimm O. Department of General Surgery, Martin-Luther-University, Halle-Wittenberg, Germany. oliver.gimm@medizin.uni-halle.de Publication Types: Review PMID: 11443849 [PubMed - indexed for MEDLINE] DR171: J Clin Endocrinol Metab. 2001 Jul;86(7):3211-6. RET/PTC rearrangements in thyroid nodules: studies in irradiated and not irradiated, malignant and benign thyroid lesions in children and adults. Elisei R, Romei C, Vorontsova T, Cosci B, Veremeychik V, Kuchinskaya E, Basolo F, Demidchik EP, Miccoli P, Pinchera A, Pacini F. Departments of Endocrinology and Metabolism, University of Pisa, Pisa 56124, Italy. Rearrangements of the RET proto-oncogene may occur in both naturally occurring and radiation-induced papillary thyroid carcinomas. Conflicting results on the frequency and type of RET/PTC rearrangements have been reported in relation to age, radiation exposure, and histological tumor variant. We designed the present study to evaluate in a single laboratory, using the same methodologies, the pattern of RET/PTC activation in thyroid tumors from different groups of patients (exposed or not exposed to radiation, children or adults, with benign or malignant tumors) in relationship to the above mentioned variables. We studied 154 patients with benign nodules (n = 65) or papillary thyroid cancer (n = 89). In the last group, 25 were Belarus children exposed to the post-Chernobyl radioactive fallout, 17 were Italian adults exposed to external radiotherapy for benign diseases, and 47 were Italian subjects (25 children and 22 adults) with no history of radiation exposure. Among patients with benign thyroid nodules, 21 were Belarus subjects (18 children and 3 adults) exposed to the post-Chernobyl radioactive fallout, 8 were Italian adults exposed to external radiation on the head and neck, and 36 were Italian adults with naturally occurring benign nodules. The overall frequency of RET/PTC rearrangements in papillary thyroid cancer was 55%. The highest frequency was found in post-Chernobyl children and was significantly higher (P = 0.02) than that found in Italian children not exposed to radiation, but not significantly higher than that found in adults exposed to external radiation. No difference of RET/PTC rearrangements was found between samples from irradiated (external x-ray) or not irradiated adult patients, as well as between children and adults with naturally occurring, not irradiated, thyroid cancer. When analyzing the type of RET/PTC rearrangement (RET/PTC1 or RET/PTC3), no major difference was apparent. In addition, eight cases with an unknown RET/PTC rearrangement and three cases with the concomitant expression of RET/PTC1 and RET/PTC3 were found. No significant correlation was observed between the frequency and/or the type of RET/PTC rearrangement and clinical-epidemiological features of the patients such as age at diagnosis, age at exposure, histological variant, gender and tumor-node-metastasis (TNM) categories. RET/PTC rearrangements were also found in 52.4% of post-Chernobyl benign nodules, in 37.5% of benign nodules exposed to external radiation and in 13.9% of naturally occurring nodules (P = 0.005, between benign post-Chernobyl nodules and naturally occurring nodules). The relative frequency of RET/PTC1 and RET/PTC3 in rearranged benign tumors showed no major difference. In conclusion, our results indicate that the presence of RET/PTC rearrangements in thyroid tumors is not restricted to the malignant phenotype, is not higher in radiation-induced tumors compared with those naturally occurring, is not different after exposure to radioiodine or external radiation, and is not dependent from young age. Other factors, probably influenced by ethnic or genetic background, may act independently from or in cooperation with radiation, to trigger the DNA damage leading to RET proto-oncogene activation. PMID: 11443191 [PubMed - indexed for MEDLINE] NR172: J Clin Endocrinol Metab. 2001 Jul;86(7):3091-6. Pseudohypoparathyroidism Ia and hypercalcitoninemia. Vlaeminck-Guillem V, D'herbomez M, Pigny P, Fayard A, Bauters C, Decoulx M, Wemeau JL. Service de Medecine Interne et Endocrinologie, CHU de Lille, 59037 Lille, France. virginie.vlaeminck@wanadoo.fr Pseudohypoparathyroidism Ia (PHP Ia) is characterized by resistance to PTH and many other stimuli because of deficiency of stimulatory G protein alpha-subunit. To determine the incidence, natural history, and mechanism of C cell dysfunction in PHP, calcitonin assays were performed in six patients with PHP Ia and four with pseudopseudohypoparathyroidism from three unrelated families. Controls included healthy subjects and patients with PHP Ib or hypoparathyroidism. The mean basal level of calcitonin was higher in PHP Ia patients than in controls (95.3 +/- 112.7 vs. 3.7 +/- 2.4 pg/mL; P = 0.005; n < 10). In PHP Ia patients, calcitonin levels rose over the normal range (30 pg/mL) after pentagastrin infusion in five patients and remained normal in one. Familial medullary thyroid carcinoma was clinically, biologically, and ultrasonographically ruled out over a mean follow-up exceeding 3 yr. Genomic screening for RET protooncogene mutations failed to reveal any anomaly. The calcitonin infusion test, which induced a significant increase in plasma cAMP in controls 30 and 60 min after infusion, failed to produce this response in PHP Ia patients, suggesting that the action of calcitonin was specifically impaired. PHP Ia may therefore be an independent etiology of hypercalcitoninemia and hyperresponsiveness to pentagastrin infusion. PMID: 11443172 [PubMed - indexed for MEDLINE] DR173: Int J Urol. 2001 Jul;8(7):398-400. Multiple endocrine neoplasia type 2B. Nakata S, Okugi H, Saitoh Y, Takahashi H, Shimizu K. Department of Urology, Ashikaga Red Cross Hospital, Ashikaga, Japan. zai23910@oak.zero.ad.jp We report a case of multiple endocrine neoplasia type 2B (MEN 2B) in a 30-year-old woman. There was no family history of MEN 2B in her family. DNA testing was carried out and a point mutation was found in exon 16, codon 918 (ATG to ACG) in the RET proto-oncogene. The woman died of medullary thyroid carcinoma, 13 years after a total thyroidectomy. Publication Types: Case Reports PMID: 11442663 [PubMed - indexed for MEDLINE] DR174: Jpn J Cancer Res. 2001 Jun;92(6):645-8. Large-scale analysis of mutations in RET exon 16 in sporadic medullary thyroid carcinomas in Japan. Takano T, Miyauchi A, Yoshida H, Hasegawa Y, Kuma K, Amino N. Department of Laboratory Medicine, Osaka University Medical School, D2 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan. ttakano@labo.med.osaka-u.ac.jp Germline mutations in the RET proto-oncogene are the cause of multiple endocrine neoplasia type 2 (MEN 2A and 2B) and familial medullary thyroid carcinoma (FMTC). Some cases of sporadic medullary thyroid carcinoma (MTC) have also been reported to have mutations in the RET gene. However, two previous reports have given discrepant results on the frequency of the mutations in RET in sporadic MTCs in Japan. To clarify this problem, we analyzed mutations in RET exon 16 in 72 sporadic MTCs by means of the two methods used in the previous studies, direct sequencing and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Mutations in exon 16 were detected in only 2 of 72 cases of sporadic MTC. These results suggest that when a MTC has a mutation in RET exon 16, it is more likely to be a hereditary MTC than a sporadic one in Japan. PMID: 11429053 [PubMed - indexed for MEDLINE] NR175: Acta Biomed Ateneo Parmense. 2000;71(1-2):25-30. [Medullary carcinoma of the thyroid gland] [Article in Italian] Del Rio P, Ferreri G, Zannoni M, Robuschi G, Sianesi M. Istituto di Clinica Chirurgica Generale e dei Trapianti d'Organo Cattedra di Chirurgia Generale, Universita degli Studi di Parma. pachi@unipr.it We report the experience of the Institute of Surgical Pathology of the University of Parma on three patients with sporadic medullary thyroid carcinoma (MTC). MTC is a tumor of parafollicolor cells origin (C cells). The surgical excision of the thyroid tumor and cervical node metastases is potentially curative. The other therapeutic options are limited. Considerable emphasis has been placed on early diagnosis and surgery for multiple endocrine neoplasia (MEN) related MTC. Genetic screening promises earlier and accurate diagnosis (RET gene mutations are found in MEN). Publication Types: Case Reports PMID: 11424598 [PubMed - indexed for MEDLINE] PR176: Oncogene. 2001 May 31;20(25):3235-46. Altered gene expression in immunogenic poorly differentiated thyroid carcinomas from RET/PTC3p53-/- mice. Powell Jr DJ, Russell JP, Li G, Kuo BA, Fidanza V, Huebner K, Rothstein JL. Department of Microbiology/Immunology and Otolaryngology-Head & Neck Surgery, Kimmel Cancer Institute, Thomas Jefferson University, Philadelphia, Pennsylvania, PA 19107, USA. Cancers develop and progress via activation of oncogenes and loss of tumor suppressor genes, a progression that can be recapitulated through cross breeding mouse strains harboring genetic mutations. To define the role of RET/PTC3, p53 and Fhit in thyroid carcinogenesis, we intercrossed RET/PTC3 transgenics with p53-/- mice. This new strain, RET/PTC3p53-/-, succumb to rapidly growing and strikingly large multilobed thyroid tumors containing mixtures of both well and poorly differentiated, highly proliferative follicular epithelial cells. Interestingly, transplanted tumors from RET/PTC3p53-/- mice grew in SCID but not syngeneic immunocompetent mice indicating that these advanced tumors were immunogenic. RET/PTC3 protein expression was reduced to undetectable levels in tumors of older mice suggesting that the continued elevated expression of RET/PTC3 may not be necessary for tumor progression. Similarly, expression of Fhit protein was reduced in early tumors and undetected in older tumors irrespective of tumor histopathology. In contrast to RET/PTC3p53-/- mice, RET/PTC3Fhit-/- mice did not develop advanced thyroid carcinomas. These studies support a model of human thyroid cancer whereby thyroid epithelium expresses RET/PTC3 protein at early stages of tumor development, followed by the reduction of RET/PTC3 and loss of p53 function with progressive reduction of Fhit protein expression coincident with malignant progression. PMID: 11423973 [PubMed - indexed for MEDLINE] DR177: J Endocrinol Invest. 2001 May;24(5):370-83. Clinical genetics of multiple endocrine neoplasias, Carney complex and related syndromes. Stratakis CA. Unit on Genetics and Endocrinology, Developmental Endocrinology Branch, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892-1862, USA. stratakc@cc1.nichd.nih.gov The list of multiple endocrine neoplasias (MENs) that have been molecularly elucidated is growing with the most recent addition of Carney complex. MEN type 1 (MEN 1), which affects primarily the pituitary, pancreas, and parathyroid glands, is caused by mutations in the menin gene. MEN type 2 (MEN 2) syndromes, MEN 2A and MEN 2B that affect mainly the thyroid and parathyroid glands and the adrenal medulla, and familial medullary thyroid carcinoma (FMTC), are caused by mutations in the REToncogene. Finally, Carney complex, which affects the adrenal cortex, the pituitary and thyroid glands, and the gonads, is caused by mutations in the gene that codes for regulatory subunit type 1A of protein kinase A (PKA) (PRKAR1A) in at least half of the known patients. Molecular defects have also been identified in syndromes related to the MENs, like Peutz-Jeghers syndrome (PJS) (the STK11/LKB1 gene), and Cowden (CD; the PTEN gene) and von Hippel-Lindau disease (VHLD; the VHL gene). Although recognition of these syndromes at a young age generally improves prognosis, the need for molecular testing in the diagnostic evaluation of the MENs is less clear. This review presents the newest information on the clinical and molecular genetics of the MENs (MEN 1, MEN 2, and Carney complex), including recommendations for genetic screening, and discusses briefly the related syndromes PJS, CD and VHLD. Publication Types: Review Review, Tutorial PMID: 11407658 [PubMed - indexed for MEDLINE] DR178: Neth J Med. 2001 Jun;58(6):236-40. Unusual clinical presentation of a patient with multiple endocrine neoplasia type 2A. Schuurman B. Department of Internal Medicine, Canisius-Wilhelmina hospital, Weg door Jonkerbos 100, 6532 SZ, Nijmegen, The Netherlands. miba@xs4all.nl The present report describes an unusual presentation of a female with MEN-2A. During 14 years she only had moderate symptoms. Occasionally she had slightly elevated basal calcitonin levels and abnormal pentagastrin tests, whereas thyroid scanning and echography were normal. At the age of 70 she developed bilateral pheochromocytoma. DNA-analysis demonstrated a germline Cys 611 Tyr mutation in the RET proto-oncogen on chromosome 10q11.2. One year after bilateral adrenalectomy again she developed overt symptoms of pheochromocytoma. The differential diagnosis and the importance of routine screening for RET mutations are discussed. Publication Types: Case Reports PMID: 11395220 [PubMed - indexed for MEDLINE] DR179: Mol Cell Biol. 2001 Jul;21(13):4177-87. Docking protein FRS2 links the protein tyrosine kinase RET and its oncogenic forms with the mitogen-activated protein kinase signaling cascade. Melillo RM, Santoro M, Ong SH, Billaud M, Fusco A, Hadari YR, Schlessinger J, Lax I. Centro di Endocrinologia ed Oncologia Sperimentale del CNR, Dipartimento di Biologia e Patologia Cellulare e Molecolare, Naples, Italy. The receptor tyrosine kinase RET functions as the signal transducing receptor for the GDNF (for "glial cell-derived neurotrophic factors") family of ligands. Mutations in the RET gene were implicated in Hirschsprung disease (HSCR), multiple endocrine neoplasia type 2 (MEN 2), and thyroid carcinomas. In this report we demonstrate that the docking protein FRS2 is tyrosine phosphorylated by ligand-stimulated and by constitutively activated oncogenic forms of RET. Complex formation between RET and FRS2 is mediated by binding of the phosphotyrosine-binding domain of FRS2 to pY1062, a residue in RET that also functions as a binding site for Shc. However, overexpression of FRS2 but not Shc potentiates mitogen-activated protein (MAP) kinase activation by RET oncoproteins. We demonstrate that oncogenic RET-PTC proteins are associated with FRS2 constitutively, leading to tyrosine phosphorylation of FRS2, MAP kinase stimulation, and cell proliferation. However, loss-of-function HSCR-associated RET mutants exhibit impaired FRS2 binding and reduced MAP kinase activation. These experiments demonstrate that FRS2 couples both ligand-regulated and oncogenic forms of RET, with the MAP kinase signaling cascade as part of the response of RET under normal biological conditions and pathological conditions, such as MEN 2 and papillary thyroid carcinomas. PMID: 11390647 [PubMed - indexed for MEDLINE] DR180: Cancer Res. 2001 Jun 1;61(11):4526-35. Nuclear factor-kappaB is constitutively active in C-cell carcinoma and required for RET-induced transformation. Ludwig L, Kessler H, Wagner M, Hoang-Vu C, Dralle H, Adler G, Bohm BO, Schmid RM. Department of Internal Medicine I, University of Ulm, Robert-Koch-Street 8, D-89081 Ulm, Germany. Specific point mutations of the RET proto-oncogene have been demonstrated to be responsible for multiple endocrine neoplasia (MEN) types 2A and 2B, for familial medullary thyroid carcinoma (MTC) syndromes, as well as for sporadic MTC. Here we show that nuclear factor (NF)-kappaB is activated in RET-associated C-cell carcinoma specimens. TT cells, a human MTC cell line expressing MEN 2A type RET, display transcriptionally active RelA(p65) in the nucleus. NF-kappaB activity in these cells is attributable to constitutive IkappaB kinase (IKK) activity and high turn over of IkappaBalpha. RET harboring the mutations C634R (MEN 2A) or M918T (MEN 2B), in contrast to wild-type RET, activates a NF-kappaB-dependent reporter construct upon transient transfection in HeLa cells. We show that the prototype RET mutation C634R enhances phosphorylation of IkappaBalpha by IKKbeta but not by IKKalpha. RET-induced NF-kappaB and IKKbeta activity requires Ras function but does neither involve the classical mitogen-activated protein kinase kinase/extracellular signal-regulated kinase nor the phosphoinositide 3-kinase/Akt pathways. In contrast, RET-induced NF-kappaB activity is dependent on Raf and MEKK1. Inhibition of constitutive NF-kappaB activity results in cell death of TT cells and blocks focus formation induced by oncogenic forms of RET in NIH 3T3 cells. These results suggest that RET-mediated carcinogenesis critically depends on IKK activity and subsequent NF-kappaB activation. PMID: 11389085 [PubMed - indexed for MEDLINE] NR181: Blood. 2001 Jun 15;97(12):3910-8. H4(D10S170), a gene frequently rearranged in papillary thyroid carcinoma, is fused to the platelet-derived growth factor receptor beta gene in atypical chronic myeloid leukemia with t(5;10)(q33;q22). Schwaller J, Anastasiadou E, Cain D, Kutok J, Wojiski S, Williams IR, LaStarza R, Crescenzi B, Sternberg DW, Andreasson P, Schiavo R, Siena S, Mecucci C, Gilliland DG. Division of Hematology, Department of Medicine, Harvard Medical School, Boston, MA, USA. The molecular cloning of the t(5;10)(q33;q22) associated with atypical chronic myeloid leukemia (CML) is reported. Fluorescence in situ hybridization (FISH), Southern blot, and reverse transcriptase- polymerase chain reaction analysis demonstrated that the translocation resulted in an H4/platelet-derived growth factor receptor betaR (PDGFbetaR) fusion transcript that incorporated 5' sequences from H4 fused in frame to 3' PDGFbetaR sequences encoding the transmembrane, WW-like, and tyrosine kinase domains. FISH combined with immunophenotype analysis showed that t(5;10)(q33;q22) was present in CD13(+) and CD14(+) cells but was not observed in CD3(+) or CD19(+) cells. H4 has previously been implicated in pathogenesis of papillary thyroid carcinoma as a fusion partner of RET. The H4/RET fusion incorporates 101 amino acids of H4, predicted to encode a leucine zipper dimerization domain, whereas the H4/PDGFbetaR fusion incorporated an additional 267 amino acids of H4. Retroviral transduction of H4/PDGFbetaR, but not a kinase-inactive mutant, conferred factor-independent growth to Ba/F3 cells and caused a T-cell lymphoblastic lymphoma in a murine bone marrow transplantation assay of transformation. Mutational analysis showed that the amino-terminal H4 leucine zipper domain (amino acids 55-93), as well as H4 amino acids 101 to 386, was required for efficient induction of factor-independent growth of Ba/F3 cells. Tryptophan-to-alanine substitutions in the PDGFbetaR WW-like domain at positions 566/593, or tyrosine-to-phenylalanine substitutions at PDGFbetaR positions 579/581 impaired factor-independent growth of Ba/F3 cells. H4/PDGFbetaR is an oncoprotein expressed in t(5;10)(q33;q22) atypical CML and requires dimerization motifs in the H4 moiety, as well as residues implicated in signal transduction by PDGFbetaR, for efficient induction of factor-independent growth of Ba/F3 cells. (Blood. 2001;97:3910-3918) PMID: 11389034 [PubMed - indexed for MEDLINE] NR182: Ophthal Plast Reconstr Surg. 2001 May;17(3):195-201. Comment in: Ophthal Plast Reconstr Surg. 2002 Mar;18(2):163-4; author reply 164. From eyelid bumps to thyroid lumps: report of a MEN type IIb family and review of the literature. Jacobs JM, Hawes MJ. Department of Ophthalmology, University of Colorado Health Sciences Center, Denver, USA. PURPOSE: We present a two-generation family with multiple endocrine neoplasia (MEN) type IIb diagnosed by their ophthalmologists based on characteristic ophthalmic findings. METHODS: A family consisting of a 33-year-old female proband and her 8- and 7-year-old children had prominent corneal nerves; eyelid, lip, and tongue nodules; and a characteristic facies. A polymerase chain reaction-based genetic assay was obtained to detect the genetic mutation most commonly associated with MEN type IIb. Serum calcitonin and urine catecholamine studies were obtained. RESULTS: Molecular genetic studies detected in all 3 patients a mutation at codon 918 of the RET proto-oncogene known to be present in 95% of the cases of MEN type IIb. Serum calcitonin was elevated in the proband and her son. Urine catecholamine levels were elevated in the proband. Surgical treatment and histologic analysis confirmed pheochromocytoma and medullary thyroid carcinoma (MTC) in the proband. Surgical exploration revealed the MTC to be metastatic to the liver. CONCLUSIONS: This family demonstrates the characteristic findings of MEN type IIb: prominent corneal nerves in a clear stroma and multiple submucosal neuromas of the conjunctiva, eyelids, lips, and tongue. Ophthalmologists have a critical role to play in recognizing these signs, because the early diagnosis of medullary thyroid carcinoma and pheochromocytoma may be life saving. Publication Types: Case Reports Review Review of Reported Cases PMID: 11388386 [PubMed - indexed for MEDLINE] DR183: Jpn J Clin Oncol. 2001 Apr;31(4):157-61. A family of multiple endocrine neoplasia type 2A with the RET proto-oncogene mutation in codon 618 (Cys-->Arg). Nakao A, Naomoto Y, Kataoka M, Haisa M, Kataoka K, Saitoh S, Fujiwara T, Yamatsuji T, Shigemitsu K, Umeoka T, Isozaki H, Futami H, Yamaguchi K, Tanaka N. First Department of Surgery, Okayama University School of Medicine, Japan. Multiple endocrine neoplasia type 2 (MEN-2) is a hereditary syndrome characterized by medullary thyroid carcinoma (MTC), pheochromocytoma and hyperplasia or adenoma of the parathyroid gland with hyperparathyroidism. Recent genetic studies have identified the presence of germline missense mutations in the RET proto-oncogene in almost 100% of MEN-2 patients. We report here three generations of one MEN-2 family with rare missense mutation at codon 618 (Cys-->Arg) of the RET proto-oncogene. The first patient was surgically treated at the age of 63 years but died of bone metastasis. His two children (29-year-old daughter and 25-year-old son) were treated surgically for MTC and neck lymph node metastasis. Germline mutations of the RET proto-oncogene of these three MTC patients and two children of the 29-year-old daughter (9-year-old female and 7-year-old male) were examined. Three MTC patients and the 9-year-old female possessed the mutation. The phenotype of the family with this rare point mutation of the RET proto-oncogene is reported. Publication Types: Case Reports PMID: 11386462 [PubMed - indexed for MEDLINE] DR184: World J Surg. 2001 Jun;25(6):713-7. Importance of early screening and prophylactic thyroidectomy in asymptomatic nonindex RET germline carriers. Ukkat J, Lorenz K, Hinze R, Thomusch O, Dralle H. Department of General Surgery, Martin-Luther-University Halle-Wittenberg, Ernst-Grube-Strasse 40, D-06097 Halle/Saale, Germany. joerg.ukkat@medizin.uni-halle.de Genetic testing for RET germline mutations affords rapid identification of germline carriers, offering the prospect of cure before C-cell hyperplasia (CCH) has progressed to medullary thyroid carcinoma (MTC). Although nonindex RET mutation carriers have a better prognosis than do the index patients, it remains to be ascertained whether age represents a risk factor for MTC when screening patients. The current institutional study (October 1994 through June 1999) was set up to compare asymptomatic nonindex patients who were grouped by age: < 20 years and > or = 20 years. Inclusion criteria were confirmed RET mutations in the germline, with no MTC being more advanced than pT1pN1M0. Adult patients (> or = 20 years) had MTC significantly more often (84% vs. 43%), significantly larger tumors (5 mm vs. 3 mm), and significantly higher basal calcitonin levels preoperatively (78.0 vs. 9.7 pg/ml) than their pediatric/adolescent counterparts (< 20 years). There was a close correlation between pT1 MTC and an elevated basal serum calcitonin level (r = 0.67; Spearman's rho). All three patients with lymph node metastases from MTC had elevated basal calcitonin levels. The two groups did not differ in terms of multifocality of MTC (pT1b), lymph node involvement (pN1) or bilateral lymph node metastasis (pN1b), or preoperative stimulated and postoperative basal and stimulated serum calcitonin. Prophylactic thyroidectomy should not be postponed beyond the age of 20, and it should be performed before basal serum calcitonin has turned positive. Pathologic conversion of stimulated serum calcitonin obviously marks the time in carriers of RET germline mutations when surgery should be scheduled at the latest to be prophylactic. PMID: 11376404 [PubMed - indexed for MEDLINE] DR185: Rays. 2000 Apr-Jun;25(2):257-66. Diagnostic approach, genetic screening and prognostic factors of medullary thyroid carcinoma. [Article in English, Italian] Corsello SM, Lovicu RM, Migneco MG, Rufini V, Summaria V. Istituto di Endocrinologia, Universita Cattolica del S. Cuore, Policlinico A. Gemelli, Roma. Medullary thyroid carcinoma is the least frequent thyroid neoplasm; it originates in thyroid parafollicular cells (calcitonin secreting C cells). In 80% of cases it is sporadic, in the remaining 20% it is familial, associated or not to other endocrinopathies as pheochromocytoma and hyperparathyroidism (MEN 2A, MEN 2B, and isolated familial medullary thyroid carcinoma). Preclinical diagnosis in relatives of affected subjects (preferably at pediatric age) is essential for successful therapy and is performed with genetic and biochemical screening tests. The genetic screening is based on DNA analysis (RET proto-oncogene mutations) of the patient, and if positive of all first degree relatives, to separate sporadic (somatic mutations) from familial (germline mutations) forms. The biochemical screening is based on calcitonin determination and its increase after pentagastrin stimulation, (a peculiar characteristic of medullary thyroid carcinoma, the first biochemical disorder in a subject at risk) and is mainly used in genetically silent familial medullary thyroid carcinoma. The principal negative prognostic factors of medullar thyroid carcinoma and the debate concerning the use of calcitonin determination in the diagnosis of the "cold" thyroid nodule have been analyzed. Publication Types: Review Review, Tutorial PMID: 11370543 [PubMed - indexed for MEDLINE] NR186: Rays. 2000 Apr-Jun;25(2):151-61. Molecular biology of thyroid neoplasms. [Article in English, Italian] Satta MA, Nanni S, Della Casa S, Pontecorvi A. Istituto di Endocrinologia, Universita Cattolica del S. Cuore, Policlinico A. Gemelli, Roma. Thyroid tumorigenesis proceeds through the progressive accumulation of alterations in genes involved in the regulation of cell proliferation and differentiation accompanying the acquisition of phenotypic, biological and clinical characteristics of increasing malignancy and dedifferentiation. The molecular alterations specific to thyrocyte carcinogenesis are examined. Ras mutations seem to represent an early occurrence in thyroid tumorigenesis being common to both benign and malignant follicular tumors; they would represent the early mutational events able to enhance the cell proliferation. Subsequent alterations in several genes will probably result in the determination of a follicular or papillary phenotype. In particular, mutational events activating ret, met and trk thyrokinase receptors direct the tumor growth and development towards the papillary type. Progression towards a follicular phenotype would instead occur in two stages: first there is the loss of function of genes on chromosome 11q13 which may direct the tumor cell towards the phenotype of follicular adenoma, second, there is the inactivation of the probable suppressor oncogene on chromosome 3p which might be fundamental in the transition from adenoma to follicular carcinoma. Undifferentiated or anaplastic tumors are characterized by the presence of p53 gene mutations. Publication Types: Review Review, Tutorial PMID: 11370534 [PubMed - indexed for MEDLINE] DR187: Oncogene. 2001 Apr 19;20(17):2161-70. Over-representation of a germline variant in the gene encoding RET co-receptor GFRalpha-1 but not GFRalpha-2 or GFRalpha-3 in cases with sporadic medullary thyroid carcinoma. Gimm O, Dziema H, Brown J, Hoang-Vu C, Hinze R, Dralle H, Mulligan LM, Eng C. Clinical Cancer Genetics and Human Cancer Genetics Programs, Comprehensive Cancer Centre, and Division of Human Genetics, Department of Internal Medicine, The Ohio State University, Columbus, Ohio, OH 43210, USA. In contrast to the hereditary form of medullary thyroid carcinoma (MTC), little is known about the etiology of sporadic MTC. Somatic gain-of-function mutations in the RET proto-oncogene, encoding a receptor tyrosine kinase, are found in an average of 40% of sporadic MTC. We analysed 31 sporadic MTC for somatic and germline variants in GFRA1, GFRA2 and GFRA3 which encode the co-receptors of RET. Although there were no somatic mutations in any of the three genes, a sequence variant (-193C>G) in the 5'-UTR of GFRA1 was found in 15% of cases. Three patients were heterozygous (het); another three patients homozygous (hom) for the G variant. The G allele was not observed in 31 race-matched normal controls. Hence, the relative frequency of this variant in sporadic MTC cases and controls differed significantly (P<0.05). Since this variant lies in the 5' UTR, likely at the transcriptional start site, we analysed for differential expression of GFRalpha-1 at the transcript and protein levels. At the mRNA level, GFRA1 was over-expressed in tumors harboring the rare variant (P=0.06). The presence of the G polymorphic allele seemed to be associated with increased expression by immunostaining for GFRalpha-1. Interestingly, cytoplasmic staining was stronger in intensity for het patients and nuclear staining predominant in hom cases. In conclusion, mutation analysis of GFRA1, GFRA2 and GFRA3 revealed over-representation of a rare variant in GFRA1 (-193C>G) in the germline of sporadic MTC cases. Our data suggest that the mechanism is related to over-expression of GFRalpha-1 and differential subcellular compartmentalization but the precise mechanism as to how it acts as a low penetrance susceptibility allele for the development of sporadic MTC remains to be elucidated. PMID: 11360200 [PubMed - indexed for MEDLINE] DR188: Surg Oncol. 2000 Nov;9(3):111-8. Multiple endocrine neoplasia type 2B--genetic basis and clinical expression. Lee NC, Norton JA. Department of Surgery, University of California, 94143, San Francisco, CA, USA. Multiple endocrine neoplasia (MEN) type 2B is a heritable endocrine disorder characterized by medullary thyroid carcinoma (MTC), pheochromocytoma, multiple mucosal neuromas, and a marfanoid habitus. Intestinal ganglioneuromatosis, corneal nerve thickening and skeletal abnormalities are also often present. The disease is inherited in an autosomal dominant fashion and is caused by a single mutation in the RET proto-oncogene, with a methionine to threonine substitution at codon 918. The MTC in MEN 2B presents at an earlier age and tends to be more aggressive than the MTC in MEN 2A. It is multicentric and bilateral and occurs as young as age 3, with early lymph node metastases. Pheochromocytoma is also often bilateral but is rarely malignant. If pheochromocytoma is detected, adrenalectomy should precede thyroidectomy to avoid intraoperative catecholamine crisis. Patients at risk for MEN 2B should undergo genetic screening in infancy. Total thyroidectomy should be performed on all patients positive for RET mutations even prior to the onset of clinical symptoms. Publication Types: Review Review, Tutorial PMID: 11356339 [PubMed - indexed for MEDLINE] DR189: Int J Oncol. 2001 Jun;18(6):1219-25. CGH alterations in medullary thyroid carcinomas in relation to the RET M918T mutation and clinical outcome. Frisk T, Zedenius J, Lundberg J, Wallin G, Kytola S, Larsson C. Department of Molecular Medicine, Endocrine Tumor Unit, Karolinska Hospital CMM L8:01, SE-171 76 Stockholm, Sweden. tony.frisk@cmm.ki.se Apart from the RET proto-oncogene (RET) no other genes have been found to be involved in medullary thyroid carcinoma (MTC) tumorigenesis. Germline RET mutations are seen virtually in all familial forms of MTC and somatic RET mutations are often detected in sporadic MTC. In sporadic MTCs the RET gene is mutated in codon 918, where a methionine is substituted to a threonine (M918T). In this study 24 MTCs were analyzed by comparative genomic hybridization (CGH) for chromosomal imbalances. Overall, alterations were detected in approximately 60% of the samples. The most common aberrations were gains on chromosome 19q (29%), 19p (21%), 11c-q12 (12.5%), and 22q (12.5%) and losses on 13q21 (21%) and 3q23-qter (12.5%). Gain of chromosome 11c-q12 was only detected in samples from patients whom died of MTC (p=0.001). These MTCs also harbored the somatic RET M918T mutation and also showed the highest numbers of CGH alterations in the series (p<0.003). Although there was a tendency towards a higher number of CGH imbalances in the tumors with RET M918T mutation, this difference was not significant. The results indicate that MTC is a comparatively genetically stable tumor, and that chromosomal regions 19q, 19p, 13q and 11q may be involved in MTC carcinogenesis. PMID: 11351254 [PubMed - indexed for MEDLINE] NR190: Med Pediatr Oncol. 2001 May;36(5):574-82. Gene rearrangements in radiation-induced thyroid carcinogenesis. Rabes HM. Institute of Pathology, University of Munich, Munich, Germany. hm.rabes@lrz.uni-muenchen.de BACKGROUND: Radiation is an accepted risk factor for thyroid carcinogenesis in children. Recent observations in large cohorts of children and young adults who developed papillary thyroid carcinomas (PTC) related to accidental radiation exposure after the Chernobyl reactor accident revealed typical genetic aberrations shedding light on genetic determinants and mechanisms of radiation-induced carcinogenesis. PROCEDURE: A molecular genetic analysis was performed on 191 post-Chernobyl PTC by RT-PCR, multiplex PCR, DNA sequencing, and in some cases 5'RACE. Determination of point mutations was by means of PCR and either allele-specific oligonucleotide hybridization or SSCP and DNA sequencing. RESULTS: In various sporadic thyroid tumor types of adults structural genetic aberrations have been found involving mutations of RAS (codon 12, 13, 61), p53 (exons 5 to 8), Gsalpha (codon 201 and 227), and, at a low prevalence, the receptor tyrosine kinases RET or NTRK1. In contrast, in radiation-induced PTC of children RET rearrangements are by far the most prevalent genetic aberrations. In these RET rearrangements, the transmembrane and extracellular domains of RET are lost, and are replaced by parts of other genes at the 5' end. These genes always contain coiled-coil domains with dimerization potential and lead to constitutive, ligand-independent activation of the ret tyrosine kinase domain at the 3' end of the fusion product. The most frequent radiation-induced RET gene fusions involve the ELE1 (ARA70) gene, a transcription coactivator of the androgen receptor (PTC3), and H4, a gene of unknown function (PTC1). Both rearrangements originate from DNA double strand breaks with repair by intrachromosomal balanced paracentric inversion and recombination by illegitimate DNA endjoining at small stretches of homologous nucleotide sequences and direct or inverted repeats, without significant breakpoint clusters in the involved introns. In addition, five different RET-fused genes, RIalpha, GOLGA5, HTIF, RFG7 and RFG8, have been detected leading to the PTC2, 5, 6, 7 and 8 types of RET rearrangements, respectively. Each fusion leads, in principle, to the same effect: The ret tyrosine kinase is uncoupled from its stringent physiological regulation by replacement of its 5' end and is aberrantly activated by the 5' parts of fused genes in thyrocytes that do not normally express ret tyrosine kinase. Ectopic ret expression, clonal expansion and early invasion are peculiar to the affected cells. The RET-fused gene is obviously decisive for modulating tumor development: ELE1/RET rearrangements lead to most rapid tumor progression and are related to the solid variant of PTC, in contrast to H4/RET rearrangements connected with papillary or follicular variants of PTC. CONCLUSIONS: Typical genetic aberrations are produced by radioiodine uptake in the juvenile thyroid gland. They act as determinants of phenotype, biology, and clinical course of radiation-induced papillary thyroid carcinomas. Copyright 2001 Wiley-Liss, Inc. PMID: 11340615 [PubMed - indexed for MEDLINE] DR191: Vestn Ross Akad Med Nauk. 2001;(2):34-7. [Molecular diagnosis of multiple type 2 endocrine neoplasia] [Article in Russian] Amosenko FA, Pushkash K, Frilling A, Kozlova VN, Liubchenko LN, Kazubskaia TP, Brelysh KE, Gar'kavtseva RF, Kalinin VN. The paper reviews the data on the molecular structure of the protooncogene RET encoding for receptor-type protein kinase, on the mechanism of transformation of the normal protooncogene RET to a dominant transforming oncogene, and on RET mutations detected in patients with the MEN-2 syndrome. Moreover, it presents the authors' own findings. The familial medullary thyroid carcinoma burdened genealogy shows a new point mutation TCG(Ser)-->GCG(Ala) in codon 891, in the exon 15 of the protooncogene RET. This mutation was not detected in the chromosomes of healthy individuals. Analyzing the linkage with two known and two new polymorphic markers showed that there was a cisaggregation of informative polymorphic markers, phenotypic manifestation of the disease, and mutations in the genealogy in question. In the protooncogene RET, there were two new polymorphisms: G/A at position 24 in intron 14 and C/T in codon 836 (exon 14). The rate of the polymorphism encountered in codon 836 proved to be similar for the Russians and the Germans (0.96%), which was also seen for two earlier described polymorphisms in codon 691 (0.80 and 0.81, respectively) and in codon 904 (0.21 and 0.22). At the same time, there were statistically significant differences in the rates of intron 14 polymorphism (0.87 and 0.77, respectively). In a family having MEN 2, a proband displayed TGC-->CGC mutation in codon 634 of the gene RET in the heterozygous state. The mutation results in substitution of cysteine amino acid residue in the cysteine-rich extracellular domain of protein kinase encoded by the gene RET for arginine. The results of molecular analysis were used to confirm its clinical diagnosis and to indicate that effective care should be delivered in MEN 2a. PMID: 11338505 [PubMed - indexed for MEDLINE] DR192: Eur J Endocrinol. 2001 May;144(5):467-73. Presentation of a kindred with familial medullary thyroid carcinoma and Cys611Phe mutation of the RET proto-oncogene demonstrating low grade malignancy. Siggelkow H, Melzer A, Nolte W, Karsten K, Hoppner W, Hufner M. Department of Gastroenterology and Endocrinology, Georg-August-University, Gottingen, Germany. hsiggel@med.uni-goettingen.de OBJECTIVE: Both multiple endocrine neoplasia type 2A (MEN 2A) and familial medullary thyroid carcinoma (FMTC) are caused by germline mutations of the RET proto-oncogene. A broad spectrum of malignancy within and between families has been described with no clear genotype-phenotype correlation due to a scarcity of available data of large kindreds. DESIGN: Here we present the only known family with a germline mutation of codon 611 TGC to TTC (exon 10) in the RET proto-oncogene leading to a replacement of cysteine by phenylalanine (Cys611Phe or C611F). RESULTS: Twenty family members of this large kindred are gene carriers (GCs) and seven (5-13 years old) are potential carriers but have yet to be analysed. The clinical course of medullary thyroid carcinoma (MTC) in this family is characterized by a very slow evolution and progression of the tumour with no MTC-related death to date. Of 11 patients (30-69 years old) having undergone thyroidectomy six were classified as pT1, four as pT2 and one as C-cell hyperplasia according to the TNM system of the International Union Against Cancer. Due to cervical and mediastinal lymph node metastasis one patient (44 years old) had to be operated on a second time. The seven non-operated GCs of the fourth and fifth generation (17-26 years old) are yearly monitored with pentagastrin stimulation tests; one non-operated GC (43 years old) has refused any further investigations. Screening for primary hyperparathyroidism and phaeochromocytoma was negative in all cases. CONCLUSION: We suggest from these experiences that the general advice for thyroidectomy in early childhood should be modified in certain families, depending on genotype. Publication Types: Case Reports PMID: 11331212 [PubMed - indexed for MEDLINE] DR193: Genomics. 2001 Apr 15;73(2):149-60. RET rearrangements in radiation-induced papillary thyroid carcinomas: high prevalence of topoisomerase I sites at breakpoints and microhomology-mediated end joining in ELE1 and RET chimeric genes. Klugbauer S, Pfeiffer P, Gassenhuber H, Beimfohr C, Rabes HM. Institute of Pathology, Ludwig Maximilians University of Munich, Thalkirchner Strasse 36, D-80337 Munich, Germany. Children exposed to radioactive iodine after the Chernobyl reactor accident frequently developed papillary thyroid carcinomas (PTC). The predominant molecular lesions in these tumors are rearrangements of the RET receptor tyrosine kinase gene. Various types of RET rearrangements have been described. More than 90% of PTC with RET rearrangement exhibit a PTC1 or PTC3 type of rearrangement with an inversion of the H4 or ELE1 gene, respectively, on chromosome 10. To obtain closer insight into the mechanisms underlying PTC3 inversions, we analyzed the genomic breakpoints of 22 reciprocal and 4 nonreciprocal ELE1 and RET rearrangements in 26 post-Chernobyl tumor samples. In contrast to previous assumptions, an accumulation of breakpoints at the two Alu elements in the ELE1 sequence was not observed. Instead, breakpoints are distributed in the affected introns of both genes without significant clustering. When compared to the corresponding wildtype sequences, the majority of breakpoints (92%) do not contain larger deletions or insertions. Most remarkably, at least one topoisomerase I site was found exactly at or in close vicinity to all breakpoints, indicating a potential role for this enzyme in the formation of DNA strand breaks and/or ELE1 and RET inversions. The presence of short regions of sequence homology (microhomologies) and short direct and inverted repeats at the majority of breakpoints furthermore indicates a nonhomologous DNA end-joining mechanism in the formation of chimeric ELE1/Ret and Ret/ELE1 genes. Copyright 2001 Academic Press. PMID: 11318605 [PubMed - indexed for MEDLINE] DR194: Hum Mutat. 2001 Apr;17(4):354. A rare variant, I852M, of the RET proto-oncogene in a patient with medullary thyroid carcinoma at age 20 years. Demeester R, Parma J, Cochaux P, Vassart G, Abramowicz MJ. Molecular Genetics, University Hospital Erasme, Free University of Brussels (ULB), B-1070 Brussels, Belgium. PMID: 11295841 [PubMed - indexed for MEDLINE] NR195: Cancer Lett. 2001 May 10;166(1):1-7. Chromosomal rearrangements in thyroid carcinomas: a recombination or death dilemma. Pierotti MA. Department of Experimental Oncology, Istituto Nazionale Tumori, Via G. Venezian 1, 20133, Milan, Italy. pierotti@istitutotumori.mi.it Well differentiated thyroid carcinomas provide a unique model of human, epithelial cell carcinogenesis. Their molecular characterization has allowed to associate specific genetic alterations to the two papillary and follicular histotypes which, despite their common origin, display different biological and clinical behaviors. A common mechanism of oncogenic activation has been observed in these tumors, based on the peculiar characteristic of thyroid epithelium to generate fusion transforming genes by chromosomal rearrangements. The reasons for this peculiar uniqueness of thyrocytes are not known, but a structural explanation, based on the spatial contiguity in the interphase nuclei of thyrocytes of the two fused genes and enzymatic features of these cells which render them apoptosis resistant to DNA damage, have been proposed to account for this behavior. Publication Types: Review Review, Tutorial PMID: 11295280 [PubMed - indexed for MEDLINE] NR196: Eur J Surg Oncol. 2001 Mar;27(2):162-4. Familial medullary thyroid carcinoma (FMTC). Study of one family (treatment criteria). Carli AF, Mariani F, Di Cosmo L, Giuli R, Neri A. Surgical Science Department, Endocrine Surgery Unit, Siena, Italy. AIM: The nosology of familial medullary thyroid carcinoma (FMTC) has been described as a distinct pathology, genetically determined and with autosomal dominant transmission with a gene penetrance of almost 100%. The diagnosis of this morbid condition can be made if at least four members of the same family are affected by calcitonin-secreting C-cell carcinoma. METHODS AND RESULTS: We report the analysis of a family in which FMTC was diagnosed between 1993 and 1998. Of the five patients we confirmed as being affected by FMTC, we were able to perform a prophylactic thyroidectomy in only one case. The high possibility of lymph-node metastasis at the time of clinical diagnosis (52-75%), and the high morbidity and radio-chemo-resistance to adjuvant therapies, indicate total thyroidectomy with central lymph-node dissection. CONCLUSION: It appears that preventive lymphadenectomy does not substantially improve survival, while pre-clinical diagnosis is of greater importance than surgery in improving survival and preventing recurrence. Total preventive thyroidectomy has been recommended in all carriers of ret genetic defects, even in families at risk with mutations of the 618 or 620 codon, because the penetrance of FMTC approaches 100%, and a 100% accordance between presence of the disease and gene carrier status is reported. This procedure would therefore represent the only possibility of achieving a 100% cure in subjects affected by familial medullary thyroid carcinoma. Copyright Harcourt Publishers Limited. PMID: 11289752 [PubMed - indexed for MEDLINE] DR197: Baillieres Best Pract Res Clin Endocrinol Metab. 2000 Dec;14(4):631-49. Diagnosis and treatment of medullary thyroid cancer. Modigliani E, Franc B, Niccoli-sire P. Groupe d'etude des tumeurs a calcitonine, Centre medical Europe, 75311 Paris, Cedex 09, France. Medullary carcinoma of the thyroid (MTC) is a rare tumour derived from thyroid C cells with serum calcitonin as a specific and sensitive marker. MTC is inherited in 25% of cases, with an autosomal dominant transmission, age-related penetrance and variable expressivity. MTC is an obligatory component of multiple endocrine neoplasia type 2 (MEN2), which comprises three well defined syndromes: MEN2A, which may be associated with pheochromocytoma and/or hyperparathyroidism; the much rarer MEN2B, which occurs early and is accompanied by developmental abnormalities; while in contrast, familial MTC (FMTC) is not associated with any endocrinopathy. The RET proto-oncogene is the causative gene of the MEN2 syndromes and mutations in this gene are found in >90% of inherited cases, allowing easier and more reliable family screening than pentagastrin stimulation tests. Nevertheless, the correlation between the genotype and the different clinical phenotypes is not perfect. The prognosis of MTC depends on its staging at presentation, and the early appearance of cervical lymph node metastases emphasizes the need for extensive surgery, although many patients still do not normalize calcitonin levels post-operatively, and they remain a challenge for the further management. Copyright 2000 Harcourt Publishers Ltd. Publication Types: Review Review, Tutorial PMID: 11289739 [PubMed - indexed for MEDLINE] DR198: Int J Cancer. 2001 Apr 1;92(1):70-4. Mutation analysis of NTRK2 and NTRK3, encoding 2 tyrosine kinase receptors, in sporadic human medullary thyroid carcinoma reveals novel sequence variants. Gimm O, Dziema H, Brown J, de la Puente A, Hoang-Vu C, Dralle H, Plass C, Eng C. Clinical Cancer Genetics Program, Division of Human Genetics, Department of Internal Medicine, Ohio State University, Columbus 43210, USA. Somatic mutations in the proto-oncogene RET are found in 25% to 80% of sporadic medullary thyroid carcinomas (MTCs). The significance of somatic RET mutation in MTC initiation and progression, however, remains unknown. Like RET, TRK is a neurotrophic receptor tyrosine kinase. Immunostaining has shown that only a subset of normal C cells expresses Trk family receptors, but in C-cell hyperplasia, they consistently express NTRK2, with variable expression of NTRK1 and NTRK3. In later stages of MTC, NTRK2 expression was reduced while NTRK3 expression was increased. In the context of these data, we sought to determine whether sequence variants in NTRK2 and NTRK3 are responsible for these differences in protein expression. We determined the genomic structure of NTRK2 and found that it consists of at least 17 exons varying in size from 36 to 306 bp. Mutation analysis of sporadic MTC did not reveal any sequence variants in NTRK2 but did reveal 3 variants in NTRK3, c.573C >T (N191N, exon 5), c.678T > C (N226N, exon 6) and c.1488C > G (A496A, exon 12) occurring among 19 chromosomes (31%), 1 chromosome (2%) and 24 chromosomes (39%), respectively. Corresponding germline also harbored these variants. There was a trend toward excess association of the NTRK3 variant c.1488C > G (A496A) in cases (24/62 chromosomes, 39%) compared to controls (18/62, 29%), but this difference did not reach significance (p > 0.05). The remaining 2 NTRK3 variants occurred with similar frequencies between MTC cases and population-matched controls (19 vs. 17 and 1 vs. 0, p > 0.05). We conclude that sequence variants in NTRK2 and NTRK3 are not likely to be responsible for large differences in expression at the protein level, but we cannot exclude very low penetrance effects. Copyright 2001 Wiley-Liss, Inc. PMID: 11279608 [PubMed - indexed for MEDLINE] DR199: Horm Metab Res. 2001 Jan;33(1):52-6. A large family with hereditary MTC: role of RET genetic analysis in differential diagnosis between MEN 2A and FMTC. Chiefari E, Chiarella R, Crocetti U, Tardio B, Arturi F, Russo D, Trischitta V, Filetti S, Zingrillo M. Cattedra di Endocrinologia, Dipartimento di Medicina Sperimentale e Clinica, Catanzaro, Italy. Germline mutations of the RET proto-oncogene cause three different cancer syndromes: multiple endocrine neoplasia type 2A (MEN 2A), multiple endocrine neoplasia type 2B (MEN 2B) and familial medullary thyroid carcinoma (FMTC). In the absence of biochemical and/or clinical evidence of pheochromocytoma and hyperparathyroidism, patients with MEN 2A disease display the same phenotype of FMTC disease, although prognosis and clinical management in both affected and unaffected familial members are quite different. We studied a family with hereditary MTC, whose proband was referred to us because of enlarged cervical nodes and increased calcitonin serum levels 28 years after the total thyroidectomy for MTC. Cervical node dissection was carried out and subsequently the presence of MTC metastasis was histologically confirmed. A RET genomic mutation at codon 634 (TGC-->TTC) was identified in the proband and in seven out of 19 familial members studied. Accordingly, a hereditary disease was suggested. However, the strong association of RET mutation at codon 634 with the presence of pheochromocytoma in MEN 2 disease suggested a more rigorous management in all gene carriers. Indeed, during the follow-up pheochromocytoma was subsequently identified in the proband. This finding suggests that all families with a pedigree suggestive of FMTC should be regarded at risk from MEN 2A disease, at least when a critical mutation in the RET cysteine domain is detected. Publication Types: Case Reports Clinical Trial PMID: 11280716 [PubMed - indexed for MEDLINE] PR200: Thyroid. 2001 Jan;11(1):93. Medullary thyroid carcinoma and lack of renal agenesis. Lombardo F, Filetti S, Crocetti U, Schlumberger M. Publication Types: Letter PMID: 11272104 [PubMed - indexed for MEDLINE] DR201: Acta Otorrinolaringol Esp. 2001 Jan-Feb;52(1):57-63. [Usefulness of RET proto-oncogene in the diagnosis of hereditary-type medullary carcinoma of the thyroid. Correlation with surgical findings] [Article in Spanish] Carreno M, Girbes J, Malluguiza R, Serrano S, Matias-Guiu X, Tudela J, Alfayate R, Lagarda H. Servicio de Otorrinolaringologia, Hospital General de Elda. med013249@nacom.es In about 25% of cases medullary thyroid carcinoma (MTC) is hereditary. In this group is possible to detect germline point mutations of the RET proto-oncogene in about 95% of the studied cases. The purpose of the present paper is to confirm the value of the RET in the screening of the hereditary MTC. We studied 43 subjects at risk for a Multiple Endocrine Neoplasia Type 2A Syndrome. RET analysis was positive for MEN 2A in 22 subjects. Fifteen of the 22 have undergone a total thyroidectomy at our facility. Histopathological study of the surgical specimens confirmed the presence of a MTC in all the cases. According with our experience. RET analysis is a 100% sensitive and specific method of hereditary MTC screening, and we think it has obvious advantages over the calcitonin tests in technical, economic and ethic aspects. PMID: 11269881 [PubMed - indexed for MEDLINE] DR202: Mod Pathol. 2001 Mar;14(3):246-53. How familial cancer genes and environmentally induced oncogenes have changed the endocrine landscape. Asa SL. University Health Network and Toronto Medical Laboratories, Toronto, Ontario, Canada. sylvia.asa@uhn.on.ca The gene responsible for MEN-2, the ret proto-ocogene, has elucidated mechanisms of endocrine tumorigenesis. Activating mutations of this transmembrane tyrosine kinase receptor represent the first known example of an inherited oncogene. This knowledge has altered our approach to affected patients by allowing in utero screening and prophylactic thyroidectomy rather than provocative testing and morphologic analysis of C cell hyperplasia--will it result in eradication of medullary carcinoma of thyroid? The lessons from Chernobyl taught us how radiation can induce chromosomal rearrangements that involve the same gene. This has led to a better understanding of papillary thyroid carcinoma and provides a novel immunohistochemical marker that widens our diagnostic armamentarium. Publication Types: Review Review, Tutorial PMID: 11266533 [PubMed - indexed for MEDLINE] DR203: Endocr Pract. 2001 Jan-Feb;7(1):19-27. Multiple endocrine neoplasia type iia: report of a family with a study of three generations in qatar. Zirie M, Mohammed I, El-Emadi M, Haider A. Department of Endocrinology/Metabolism and Internal Medicine and Department of General Surgery, Hamad General Hospital, Doha, Qatar. OBJECTIVE: To study the pattern of multiple endocrine neoplasia type IIA (MEN IIA) and describe the clinical features and results of genetic testing and treatment in 21 members of the first reported family with MEN IIA in Qatar. METHODS: After identification of the proband, we screened all her family members (21 members) with genetic testing for the RET proto-oncogene mutation. Those subjects with the mutation were further assessed for pheochromocytoma by measurement of the 24-hour urinary vanillylmandelic acid, metanephrines, and catecholamines, and those with high levels underwent a metaiodobenzylguanidine scan and adrenalectomy. The serum calcium was measured in a effort to detect hyperparathyroidism. Those family members who had the mutation and were eligible for surgical treatment underwent total thyroidectomy and central compartment dissection. In those patients with high postoperative calcitonin levels, residual disease was sought with radiologic imaging, and follow-up was done with pentagastrin stimulation tests. RESULTS: Of the 21 family members screened, 10 had the RET proto-oncogene mutation (codon 634, TGC->GGC) (5 females and 5 males; 6 adults and 4 children). All the adults had bilateral medullary thyroid carcinoma (MTC); four of them had lymph node metastatic lesions, and one had metastatic involvement of the liver. Two adults had pheochromocytomas. Two family members were reported to have parathyroid hyperplasia, although both were normocalcemic. CONCLUSION: This family with MEN IIA showed classic mendelian autosomal dominant inheritance. All adult patients had MTC, two had pheochromocytomas, and two had parathyroid hyperplasia. Although one child had a high stimulated calcitonin level, the histopathologic findings were normal; another child with high stimulated calcitonin levels showed C-cell hyperplasia on histopathologic examination. Publication Types: Case Reports PMID: 11250764 [PubMed - indexed for MEDLINE] DR204: Cancer Res. 2001 Feb 15;61(4):1426-31. Increased in vivo phosphorylation of ret tyrosine 1062 is a potential pathogenetic mechanism of multiple endocrine neoplasia type 2B. Salvatore D, Melillo RM, Monaco C, Visconti R, Fenzi G, Vecchio G, Fusco A, Santoro M. Centro di Endocrinologia ed Oncologia Sperimentale del CNR, Universita di Napoli Federico II, Italy. Mutations of the Ret receptor tyrosine kinase are responsible for inheritance of multiple endocrine neoplasia (MEN2A and MEN2B) and familial medullary thyroid carcinoma syndromes. Although several familial medullary thyroid carcinoma and most MEN2A mutations involve substitutions of extracellular cysteine residues, in most MEN2B cases there is a methionine-to-threonine substitution at position 918 (M918T) of the Ret kinase domain. The mechanism by which the MEN2B mutation converts Ret into a potent oncogene is poorly understood. Both MEN2A and MEN2B oncoproteins exert constitutive activation of the kinase. However, the highly aggressive MEN2B phenotype is not supported by higher levels of Ret-MEN2B kinase activity compared with Ret-MEN2A. It has been proposed that Ret-MEN2B is more than just an activated Ret kinase and that the M918T mutation, by targeting the kinase domain of Ret, might alter Ret substrate specificity, thus affecting Ret autophosphorylation sites and the ability of Ret to phosphorylate intracellular substrates. We show that the Ret-MEN2B mutation causes specific potentiated phosphorylation of tyrosine 1062 (Y1062) compared with Ret-MEN2A. Phosphorylated Y1062 is part of a Ret multiple effector docking site that mediates recruitment of the Shc adapter and of phosphatidylinositol-3 kinase (PI3K). Accordingly, we show that Ret-MEN2B is more active than Ret-MEN2A in associating with She and in causing constitutive activation of the Ras/mitogen-activated protein kinase and PI3K/Akt cascades. We conclude that the MEN2B mutation specifically potentiates the ability of Ret to autophosphorylate Y1062 and consequently to couple to the Ras/mitogen-activated protein kinase and the PI3K/Akt pathways. The more efficient triggering of these pathways may account for the difference between MEN2A and MEN2B syndromes. PMID: 11245446 [PubMed - indexed for MEDLINE] DR205: Int J Cancer. 2001 Jan 20;95(1):62-6. Prognostic value of codon 918 (ATG-->ACG) RET proto-oncogene mutations in sporadic medullary thyroid carcinoma. Schilling T, Burck J, Sinn HP, Clemens A, Otto HF, Hoppner W, Herfarth C, Ziegler R, Schwab M, Raue F. Department of Internal Medicine I, University of Heidelberg, Heidelberg, Germany. Tobias_Schilling@med.uni-heidelberg.de We have determined the frequency of 918 RET proto-oncogene mutations (ATG-->ACG) in primary MTC tumors and metastases and correlated the presence or absence of this mutation with the clinical outcome of patients suffering from sporadic medullary thyroid carcinoma (MTC). A total of 197 samples, consisting of both primary tumors and lymph node metastases from 34 patients with sporadic MTC, were collected for PCR analysis of the RET 918 mutation. In 75 of the samples (38%), codon 918 (ATG-->ACG) mutations could be detected. The mutations showed a heterogeneous distribution: 21/34 patients (62%) had mutations in at least 1 tumor sample, and in 13 patients (38%) the mutation was present in all examined samples. Patients were considered 918mt when at least 1 tumor sample showed the RET 918 mutation. These 918mt and 918 wild-type (918wt) patients did not differ significantly concerning sex, age at diagnosis, TNM stage at diagnosis, number of examined tumor samples or follow-up time. However, 918mt patients showed more aggressive development of distant metastases during follow-up (p = 0.032, Fisher's exact test) with decreased metastases-free survival (p < 0.005, log-rank test). Furthermore, 918mt patients had a significantly lower survival rate than 918wt patients (p = 0.048, log-rank test). These data show that the RET codon 918 mutation has a prognostic impact on patients with sporadic MTC which may influence follow-up treatment. Copyright 2001 Wiley-Liss, Inc. PMID: 11241313 [PubMed - indexed for MEDLINE] DR206: J Clin Endocrinol Metab. 2001 Mar;86(3):1104-9. Genotype-phenotype correlations in hereditary medullary thyroid carcinoma: oncological features and biochemical properties. Machens A, Gimm O, Hinze R, Hoppner W, Boehm BO, Dralle H. Department of General Surgery, Martin Luther University Halle-Wittenberg, D-06097 Halle/Saale, Germany. In hereditary medullary thyroid carcinoma (MTC), few genotype-phenotype correlations have been established. RET genotypes (exons 10, 11, 13, and 14) of 63 patients with hereditary MTC (from November 1994 to October 1999) were correlated with age at diagnosis, sex, the TNM system, and basal calcitonin levels. Mutations in exons 10, 11, 13, and 14 were demonstrated in 22% (14 of 63), 54% (34 of 63), 21% (13 of 63), and 3% (2 of 63). The median ages at diagnosis differed significantly (38, 27, 52, and 62 yr; P = 0.003). When grouped by cysteine codons (exons 10 and 11 vs. exons 13 and 14), this difference became even more evident (30 vs. 56 yr; P = 0.001). Apart from age at diagnosis, no other significant associations were noted. Based hereon, three MTC risk groups were devised according to genotype: a high risk group (codons 634 and 618) with the youngest ages of 3 and 7 yr at diagnosis; an intermediate risk group (codons 790, 620, and 611) with ages of 12, 34, and 42 yr; and a low risk group (codons 768 and 804) with ages of 47 and 60 yr, respectively. Age at diagnosis was unrelated to specific nucleotide and amino acid exchange within each codon. The current data demonstrate that there is a significant genotype-phenotype correlation, allowing for a more individualized approach to the timing and extent of prophylactic surgery. PMID: 11238493 [PubMed - indexed for MEDLINE] PR207: Biomed Pharmacother. 2001 Feb;55(1):39-53. Pathogenesis of thyroid nodules: histological classification? Salabe GB. CNR Institute of Neurobiology and Molecular Medicine, Rome, Italy. Giovanni.Battista.Salabe@ims.rm.cnr.it Thyroid nodule genesis may be considered as an amplification of thyroid heterogeneity due to genetic and/or epigenetic mechanisms. We classified the thyroid nodules in five types with distinct histological features: hyperplastic, neoplastic, colloid, cystic and thyroiditic nodules. Hyperplastic: Thyrocyte proliferation is under the control of TSH but several other paracrine and autocrine factors are secreted by follicular cells, the stromal apparatus and the lymphocytes, which are implicated in initiation and perpetuation of thyroid hyperplasia. Growth occurs mainly through TSHR, cAMP and PKA. Constitutive cAMP overproduction has been shown to be due to point mutation of the TSHR or Gs protein, producing overgrowth and hyperfunction. Neoplastic: Several activated oncogenes have been identified in thyroid malignancies. Oncogenes relevant to the thyroid carcinogenesis are: mutated TSHR and gsp (constitutive activation of cAMP); TRK (receptor for NGF); RET/PTC (phosphorylation of tyrosine kinase receptor)--an isoform of this oncogene is induced by radiation: ras (it encodes Gs proteins transducing mitogenic signals); and c-MET (receptor for hepatocyte growth factor). The evolution of a differentiated thyroid cancer towards an undifferentiated cancer is due to a mutation of a family of proteins (i.e., p53), which acts as a brake, preventing the genomic instability of cancer. It is suggested that a tumor initiates by RET or ras and possibly progresses--as a result of additional mutations and by p53 mutation--to anaplastic carcinoma. Colloid: Flattening of the epithelium and dilatation of follicles containing viscous material--made up by a concentrated solution of thyroglobulin (hTg)--is the characteristic of the colloid nodule. A defect of intraluminal reabsorption of hTg has been suggested but not proven. Experimentally, a load of iodine is able to change thyroid hyperplasia to a colloid feature; however, a load of iodine is rarely found in the clinical history of patients. A new clue to the pathogenesis comes from the finding that a relevant part of the colloid (10-20%) is made up of insoluble globules, where hTg is compacted in a polymeric form. It is suggested that stocking hTg into globules is defective in colloid nodules, leading to enormous enlargement of the follicle. Cystic: It is estimated that between 15 and 40% of thyroid nodules are partly or entirely cystic. The 'true cyst' is rare; most of the so-called cystic nodules are 'pseudocysts', which follow necrosis and colliquation. Necrosis issues as an imbalance between growth and the precisely regulated process of angiogenesis. More recently, the VEGF/VPF has been found to be at the origin of recent and recurrent cysts. Immunotoxic and apoptotic mechanisms have also been suggested. Chemical analysis of cystic fluid showed a 'denatured' and 'serum-like' pattern suggesting different mechanisms in the pathogenesis of the pseudocystic thyroid nodules. Thyroiditic: Nodular lymphocytic thyroiditis (NLT) includes two different entities: 1) lymphocyte thyroiditis growing as a nodule in a hyperplastic or normal gland, and 2) lymphocyte thyroiditis associated in the same nodule with other nodular diseases of the thyroid: papillary thyroid carcinoma and lymphoma have been found to be associated to chronic lymphocytic thyroiditis. Publication Types: Review Review, Tutorial PMID: 11237284 [PubMed - indexed for MEDLINE] DR208: J Clin Endocrinol Metab. 2001 Jan;86(1):427-32. Thyroid carcinoma usually occurs in patients with familial adenomatous polyposis in the absence of biallelic inactivation of the adenomatous polyposis coli gene. Cetta F, Curia MC, Montalto G, Gori M, Cama A, Battista P, Barbarisi A. Interuniversity Center for Research in Hepatobiliary Disease, Institute of Surgical Clinics, University of Siena, 53100 Siena, Italy. cetta@unisi.it Papillary thyroid carcinoma (PTC) is a rare extracolonic manifestation of familial adenomatous polyposis, determined by germline mutations of the adenomatous polyposis coli (APC) gene. The aim of this study was to assess the presence of loss of heterozygosity of APC in the thyroid tumoral tissue. Specimens from six female patients, aged 20-36, were analyzed for germline and somatic mutations of the APC gene by restriction enzyme analysis and sequence analysis. Five of the six also had analysis for ret/PTC, a chimeric gene, the activation of which is restricted to papillary TC. Because a previous study showed that germline mutations in familial adenomatous polyposis-associated thyroid carcinoma were located between codons 140 and 1513, the search for somatic mutations of the APC gene was restricted to this genomic area. Three of the six patients, belonging to the same kindred, had a germline mutation at codon 1061. The remaining three, one per kindred, had germline mutations at codons 1061, 1061, and 1309, respectively. None of the six patients had loss of heterozygosity for APC or somatic mutation in the explored genomic area (codon 545 and codons 1061-1678). Four of five had activation of ret/PTC in the thyroid tumoral tissue, as ret/PTC1 isoform. Either APC has a tissue-specific dominant effect in the thyroid gland or the germline mutation confers a generic susceptibility to cancer development, but other factors (sex-related factors, environmental radiation, modifier genes) are also required for TC development. This usually involves ret/PTC activation, suggesting a possible cooperation between altered function of APC and gain of function of ret. PMID: 11232035 [PubMed - indexed for MEDLINE] DR209: J Clin Oncol. 2001 Mar 1;19(5):1374-80. Estimation of risk of inherited medullary thyroid carcinoma in apparent sporadic patients. Wiench M, Wygoda Z, Gubala E, Wloch J, Lisowska K, Krassowski J, Scieglinska D, Fiszer-Kierzkowska A, Lange D, Kula D, Zeman M, Roskosz J, Kukulska A, Krawczyk Z, Jarzab B. Departments of Nuclear Medicine and Endocrine Oncology, Center of Oncology, Maria Sklodowska-Curie Memorial Institute, Gliwice, Poland. PURPOSE: The study was undertaken to evaluate the frequency of inherited medullary thyroid carcinoma (MTC) among patients with apparent sporadic disease. A stepwise algorithm was used depending on clinical indices and the age of patient at MTC diagnosis. PATIENTS AND METHODS: One hundred sixteen patients with MTC verified by postoperative pathologic examination were subjected to genetic analysis of RET exons 10, 11, 13, 14, and 16 by means of polymerase chain reaction, restriction endonuclease digestion, and DNA sequencing. RESULTS: Among 116 apparent sporadic MTC patients, we identified eleven (9.5%) RET germline mutation carriers. Seven of these (6.0%) were found by routine analysis (exons 10 and 11). The frequency of inherited disease among patients younger than 45 years at diagnosis was 10.2% by analysis of typical mutations in exons 10 and 11. Extended genetic analysis (sequencing of exons 11, 13, 14, and 16) yielded 6.1% additional diagnoses, giving a risk of 16.3% in this age group. One previously unreported mutation in exon 11 affected codon 649 (TCG>TTG, Ser>Leu). In the true sporadic MTC patients younger than 30 years at diagnosis, frequencies of 36% and 4.5% in polymorphic variants L769L and S836S, respectively, were observed. The frequency for L769L was higher than in older patients (P <.05). CONCLUSION: The frequency of inherited disease among apparent sporadic medullary thyroid carcinoma patients is close to 10% in the Polish population of MTC patients. The extended analysis of all known RET proto-oncogene mutation sites is obligatory in patients younger than 45 years at diagnosis, but we also see the need to analyze the impact of rarer mutations in older patients. PMID: 11230481 [PubMed - indexed for MEDLINE] DR210: J Endocrinol Invest. 2001 Jan;24(1):51-5. RET proto-oncogene mutation in a mixed medullary-follicular thyroid carcinoma. Orlandi F, Chiefari E, Caraci P, Mussa A, Gonzatto I, De Giuli P, Giuffrida D, Angeli A, Filetti S. Department of Clinical and Biological Sciences, University of Torino, Italy. orlandi@molinette.unito.it A case of a patient with an uncommon thyroid carcinoma, showing histological and immunohistochemical features of both follicular and parafollicular cells is described. Somatic point mutation (ATG to ACG heterozygotic mutation at codon 918) of the RET proto-oncogene was detected in tumor tissue, as confirmed by immunohistochemical expression of RET oncoprotein. Our findings suggest that constitutive RET proto-oncogene activation may be involved in the development of mixed medullary-follicular thyroid carcinoma. Publication Types: Case Reports PMID: 11227733 [PubMed - indexed for MEDLINE] DR211: Anticancer Res. 2000 Nov-Dec;20(6C):4877-87. Multiple endocrine neoplasia (MEN)--an overview and case report--patient with sporadic bilateral pheochromocytoma, hyperparathyroidism and marfanoid habitus. Fassbender WJ, Krohn-Grimberghe B, Gortz B, Litzlbauer D, Stracke H, Raue F, Kaiser HE. Medical Department III, RWTH University Clinic, Pauwelsstr. 30,52074 Aachen, Germany. wjfassbender@post.klinikun.rwth-aachen.de The multiple endocrine neoplasia syndromes are divided into two categories: MEN type I and MEN type II. The MEN type II syndrome is further divided into MEN IIa and MEN IIb. The syndromes are characterized by benign and malignant changes in two or more endocrine organs, as well as incidental changes in nervous, muscular and connective tissue. Two main forms can be distinguished: the MEN-I syndrome with hyperplasia of the parathyroid gland, accompanied by islet cell tumor and pituitary adenoma; the MEN-II syndrome with medullary thyroid carcinoma in combination with bilateral pheochromocytoma and hyperplasia of the parathyroid gland (MEN IIa), while type IIb is characterized by the additional appearance of neurocutaneous manifestations without primary hyperparathyroidism. Characteristics shared by these syndromes include the involved cell type, most of the tumors are composed of one or more specific polypeptide- and biogenic amine-producing cell types (APUD--amine precursor uptake and decarboxylation). The second characteristic is the increased incidence in certain families. The hereditary component is autosomal dominant with variable expression but high penetrance. Mechanisms of tumorigenesis differ in these syndromes. While MEN I is caused by an inherited mutation of a tumor suppressor gene, menin, located on the long arm of chromosome 11, MEN II is caused by activation of the RET proto-oncogene. We have reported the case of a young man exhibiting bilateral pheochromocytoma. In addition, the patient showed mild primary hyperparathyroidism and marfanoid habitus, all these stigmata usually being part of the MEN-II syndrome. Although this described patient showed a phenotypic mixture of the MEN-IIa and MEN-IIb syndrome, the genetic analysis for MEN II and von-Hippel-Lindau gene did not reveal any pathologic mutations, the endocrine disorders described here are not related to multiple endocrine neoplasia syndromes. Publication Types: Case Reports Review PMID: 11205236 [PubMed - indexed for MEDLINE] DR212: Eur J Pediatr Surg. 2000 Oct;10(5):334-6. Prophylactic thyroidectomy in the treatment of thyroid medullary carcinoma. Age for surgery? Hassett S, Costigan C, McDermott M, Fitzgerald RJ. Department of Paediatric Surgery, Our Lady's Hospital for Sick Children, Dublin, Ireland. Since the association of RET proto-oncogene mutations and medullary thyroid carcinoma in children there has been much discussion regarding timing of surgery. Our study group was formed from a brother and sister (8 and 5) and 3 brothers (9, 13, 16) selected on the basis of a positive family history for thyroid medullary carcinoma. Histological examinations of the thyroidectomy specimens showed that the 8- and 9-year old had microinvasive carcinoma and the remaining three had C-cell hyperplasia. Our recommendation is for prophylactic thyroidectomy for children with RET proto oncogene mutations at an early age, clearly before age 5. Publication Types: Case Reports PMID: 11194546 [PubMed - indexed for MEDLINE] DR213: Tidsskr Nor Laegeforen. 2000 Nov 10;120(27):3249-52. [Prophylactic thyroidectomy in carriers of RET oncogene mutation carriers] [Article in Norwegian] Hoie J, Heimdal K, Nesland JM, Bormer O. Avdeling for kirurgisk onkologi, Det Norske Radiumhospital, 0310 Oslo. johanhoi@online.no BACKGROUND: Medullary thyroid cancer may be inherited dominantly. Germline mutations in the RET oncogene which code for a receptor tyrosine kinase cause MEN2. Thyroidectomy is recommended in family members who carry a mutation. MATERIAL AND METHODS: We have thyroidectomized four children from three families, 12, 10, 7 and 6 years old, because of germline mutations. RESULTS: The 12-year-old had developed a minimal medullary cancer with microscopic lymph node metastases; the others showed variable degrees of C-cell hyperplasia. The mutations were located on exon 10 (C620F) in the two patients from one family, on exon 11 (C634R) in the second family and on exon 14 (V804M) in the third family. In the families with the codon 620 and codon 634 mutations, only medullary thyroid cancer has been diagnosed. In the family with the codon 804 mutation, the index patient has been operated for a pheochromocytoma. The longterm clinical course seems more favorable in the family with the codon 620 mutation than in the two other families. With knowledge of the family mutations, we found that two out of nine family members we previously have thyroidectomized following calcitonin testing did not carry the family mutation. INTERPRETATION: Genetic diagnostic is a safe and reliable predictive test for familial medullary thyroid cancer and should be carried out in any individual with this cancer. Thyroidectomy is recommended in gene carriers at the age of six. PMID: 11187163 [PubMed - indexed for MEDLINE] NR214: Science. 2000 Oct 6;290(5489):62-3. Comment on: Science. 2000 Oct 6;290(5489):138-41. Cancer. Proximity matters. Savage JR. Publication Types: Comment PMID: 11183150 [PubMed - indexed for MEDLINE] NR215: Eur J Endocrinol. 2001 Jan;144(1):37-44. Pheochromocytoma in multiple endocrine neoplasia type 2: a prospective study. Nguyen L, Niccoli-Sire P, Caron P, Bastie D, Maes B, Chabrier G, Chabre O, Rohmer V, Lecomte P, Henry JF, Conte-Devolx B; French Calcitonin Tumors Study Group. Service d'Endocrinologie, Hopital de la Timone, Marseille, France. OBJECTIVE: The aim of this prospective study is to update our knowledge of the chronology of pheochromocytoma occurrence in multiple endocrine neoplasia type 2 (MEN 2), and to better manage MEN 2 patients after the genetic diagnosis. DESIGN: Eighty-seven non-index gene carrier MEN 2 patients were included in this prospective study: 84 patients with MEN 2A (from 52 families) and 3 with MEN 2B (from 3 families). METHODS: Medullary thyroid carcinoma (MTC) was diagnosed by measuring plasma calcitonin in basal conditions or after pentagastrin stimulation. The search for pheochromocytoma consisted of clinical evaluation, 24 h determination of urinary catecholamines and adrenal imaging. The mean age at genetic diagnosis of MEN 2 was 14.0+/-7.0 years, the mean duration for the follow-up was 7.6+/-2.8 years. RESULTS: All 87 patients had a MTC detected at the same time as the genetic diagnosis was made. Urinary catecholamine measurements led to the diagnosis of pheochromocytoma and a combination of imaging techniques enabled the correct localization of both unilateral or bilateral adrenal involvement. Pheochromocytoma was detected simultaneously with MTC in only seven patients, and seven others were detected throughout the follow-up. Of the 14 patients with pheochromocytoma, 11 had bilateral involvement: nine were initially bilateral and two became so during follow-up. CONCLUSION: This study demonstrates that in MEN 2, MTC is the lesion which appears earliest. Pheochromocytoma develops later during the evolution of the disease, and necessitates regular clinical and biological monitoring throughout follow-up. Determination of urinary and/or plasma catecholamines and metanephrines should be performed to detect pheochromocytoma. Imaging techniques lead to the detection of both unilateral and bilateral pheochromocytoma, thus making video-assisted laparoscopic adrenalectomy possible. PMID: 11174835 [PubMed - indexed for MEDLINE] DR216: Cancer Lett. 2001 Feb 26;163(2):143-56. Thyroid cancer. Gimm O. Department of General Surgery, Martin-Luther-University Halle-Wittenberg, Halle, Germany. oliver.gimm@medizin.uni-halle.de Four types of thyroid cancer comprise more than 98% of all thyroid malignancies. Papillary thyroid carcinoma (PTC) may have a very benign course while undifferentiated thyroid carcinoma (UTC) belongs to the most aggressive human malignancies. A variety of genes have been identified to be involved in the pathogenesis of thyroid carcinoma. Somatic Ras mutations seem to be an early event and are frequently found in follicular thyroid carcinomas. Somatic rearrangements of RET and TRK are almost exclusively found in PTC and may be found in early stages. Germline RET missense mutations lead to hereditary medullary thyroid carcinoma (MTC). In contrast, the significance of somatic RET mutations in sporadic MTC is unknown. p53 seems to play a crucial role in the dedifferentiation process of thyroid carcinoma. The precise role of PTEN remains to be elucidated. The only clearly identified exogenous factor that may lead to thyroid carcinoma (mainly PTC) is radiation. Of interest, radiation is capable to induce RET rearrangements. In general, early diagnosis is mandatory to enable the chance of cure. Surgery is the treatment of choice. Depending on the tumour type, surgery in combination with either radioiodine, external radiation or chemotherapy often enables the control of local tumour burden. In MTC and UTC, once thyroid cancer is spread to distant organs, efficacious therapeutic agents are almost non-existing. However, our growing knowledge of genes involved in thyroidal oncogenesis may contribute to the development of more effective treatment modalities. Some preliminary data on gene therapy are quite promising. Publication Types: Review Review, Tutorial PMID: 11165748 [PubMed - indexed for MEDLINE] NR217: Cancer Res. 2000 Dec 15;60(24):7048-51. Sporadic and familial pheochromocytomas are associated with loss of at least two discrete intervals on chromosome 1p. Benn DE, Dwight T, Richardson AL, Delbridge L, Bambach CP, Stowasser M, Gordon RD, Marsh DJ, Robinson BG. Cancer Genetics, Kolling Institute of Medical Research, Royal North Shore Hospital, St. Leonards, New South Wales, Australia. Pheochromocytomas are tumors of the adrenal medulla originating in the chromaffin cells derived from the neural crest. Ten % of these tumors are associated with the familial cancer syndromes multiple endocrine neoplasia type 2, von Hippel-Lindau disease (VHL), and rarely, neurofibromatosis type 1, in which germ-line mutations have been identified in RET, VHL, and NF1, respectively. In both the sporadic and familial form of pheochromocytoma, allelic loss at 1p, 3p, 17p, and 22q has been reported, yet the molecular pathogenesis of these tumors is largely unknown. Allelic loss at chromosome 1p has also been reported in other endocrine tumors, such as medullary thyroid cancer and tumors of the parathyroid gland, as well as in tumors of neural crest origin including neuroblastoma and malignant melanoma. In this study, we performed fine structure mapping of deletions at chromosome 1p in familial and sporadic pheochromocytomas to identify discrete regions likely housing tumor suppressor genes involved in the development of these tumors. Ten microsatellite markers spanning a region of approximately 70 cM (1pter to 1p34.3) were used to screen 20 pheochromocytomas from 19 unrelated patients for loss of heterozygosity (LOH). LOH was detected at five or more loci in 8 of 13 (61%) sporadic samples and at five or more loci in four of five (80%) tumor samples from patients with multiple endocrine neoplasia type 2. No LOH at 1p was detected in pheochromocytomas from two VHL patients. Analysis of the combined sporadic and familial tumor data suggested three possible regions of common somatic loss, designated as PC1 (D1S243 to D1S244), PC2 (D1S228 to D1S507), and PC3 (D1S507 toward the centromere). We propose that chromosome 1p may be the site of at least three putative tumor suppressor loci involved in the tumorigenesis of pheochromocytomas. At least one of these loci, PC2 spanning an interval of <3.8 cM, is likely to have a broader role in the development of endocrine malignancies. PMID: 11156410 [PubMed - indexed for MEDLINE] DR218: Cancer Res. 2000 Dec 15;60(24):7028-32. A novel type of RET rearrangement (PTC8) in childhood papillary thyroid carcinomas and characterization of the involved gene (RFG8). Klugbauer S, Jauch A, Lengfelder E, Demidchik E, Rabes HM. Institute of Pathology, Ludwig Maximilians University of Munich, Germany. As part of ongoing studies on the RET rearrangement frequency in children with papillary thyroid carcinoma (PTC) after their exposure to radioactive iodine after the Chernobyl reactor accident, new methods for the detection of novel types of RET rearrangements are being developed. In this study, an improved reverse transcription-PCR strategy is used successfully to identify a new type of RET rearrangement. This rearrangement is designated PTC8 and the involved RET-fused gene (RFG) as RFG8. The identification of two reciprocal transcripts coding for the RFG8/RET and RET/RFG8 fusions suggests that the PTC8 rearrangement results from a balanced chromosomal translocation. With a view to clarify its role in tumor induction, we compared the fusion products with those of previously described RET rearrangements. We therefore sequenced and characterized the RFG8 cDNA, which showed no significant similarity to any functional protein described as yet. RFG8 is located on chromosome 18q21-22 and is expressed ubiquitously. Bioinformatic analysis predicts with a high probability that the corresponding rfg8 protein is located in the cytoplasm and is involved putatively in intracellular transport processes. Furthermore, we identified coiled-coil structures upstream of the breakpoint with one of the coiled-coils showing dimerization capability. Thus the rfg8/ret fusion protein exhibits structures for oncogenic activation that are similar to those observed in previously described RET fusions. PMID: 11156407 [PubMed - indexed for MEDLINE] NR219: J Biol Chem. 2001 Mar 23;276(12):9460-7. Epub 2000 Dec 19. Differential effects of leukocyte common antigen-related protein on biochemical and biological activities of RET-MEN2A and RET-MEN2B mutant proteins. Qiao S, Iwashita T, Furukawa T, Yamamoto M, Sobue G, Takahashi M. Department of Pathology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan. Protein-tyrosine-phosphatases (PTPs), in conjunction with protein-tyrosine kinases, play essential regulatory roles in diverse cellular activities by modulating the phosphorylation state of target proteins. Leukocyte common antigen-related (LAR) protein is a widely expressed receptor-type protein-tyrosine-phosphatase that is implicated in the regulation of intracellular signaling triggered by both cell adhesion and peptide growth factors. The gene for LAR is localized to human chromosome 1p32, a region frequently deleted in tumors of neuroectodermal origin, including neuroblastoma, pheochromocytoma, and medullary thyroid carcinoma. On the other hand, the RET gene codes for a transmembrane tyrosine kinase and is responsible for the development of multiple endocrine neoplasia (MEN) 2A and 2B. To explore the potential role of LAR in RET tyrosine kinase activity and RET-induced signal transduction, we cotransfected LAR and RET with a MEN2A or MEN2B mutation (designated RET-MEN2A or RET-MEN2B) into the NIH 3T3 cell line. Here we show that LAR reduces the constitutive tyrosine autophosphorylation and kinase activity of RET-MEN2A but not RET-MEN2B, accompanying a significant decrease of phosphorylation of phospholipase Cgamma, AKT, and ERK1/2. Interestingly, LAR expression significantly decreased the levels of disulfide-linked RET-MEN2A dimerization. Moreover, reduced oncogenic activity of RET-MEN2A by overexpression of LAR was observed both by an in vitro colony formation assay and by in vivo tumorigenicity in scid mice. These results thus suggest that LAR may contribute to deactivation of the RET-MEN2A mutant protein and reduction of its oncogenic activity in vivo. PMID: 11121408 [PubMed - indexed for MEDLINE] DR220: Neoplasma. 2000;47(5):323-6. Medullary thyroid carcinoma (MTC)--clinical and molecular aspects on the basis of own experience. Pomorski L, Bartkowiak J, Pisarek H, Bartos M, Narebski J. Clinic of Endocrinological and General Surgery, Medical Unitversity of Lodz, Poland. In our clinic 19615 patients were operated over 25 years on for goiter. Malignant thyroid neoplasms were found in 1049 (5.3%) patients including 875 (83.4%) women and 174 (16.6%) men. Sixty two adult patients (42 women and 20 men were operated on for medullary thyroid carcinoma (MTC). Thyroid cancer was diagnosed in this group pre or intraoperatively in 44 (71%) patients and postoperatively, on histologic examination, in 18 (29%) patients. These patients were reoperated. Radical operations (total thyroidectomy with regional lymph node removal) were conducted in 43 (69.3%) patients and palliative ones in 19 (30.7%) patients. After MTC surgery, MEN 2A (MTC and an adrenal tumor) were diagnosed by means of imaging techniques (USG, CT) in 6 (9.7%) patients. All adrenal tumors were unilateral. Five of these patients were operated, and pheochromocytoma was confirmed by histopathologic examination. Two years after the MTC operation, 1 women was lost to follow-up. After a year, she was admitted to hospital for severe hypertension and died of cerebral hemorrhagia. Pheochromocytoma was revealed by autopsy. All patients were treated complementarily after the MTC operation. Different combinations of teleradiotherapy, chemotherapy and substitutive doses of levothyroxine were used. Ten (23.2%) of 43 patients operated radically were reoperated 1-3 years after the first operation due to loco-regional tumor recurrence. Radical reoperations were performed in 4 patients, and palliative ones in 6. Over a 0.5-23-year follow-up period, 26 (41.9%) patients died, including 20 of cancer, and 6 of other reasons. Four out of 36 living patients have clinical or biochemical symptoms of neoplastic disease. The follow-up period of MEN 2 patients operated on ranged from 1 to 6 years. Up to now, no tumor in the second adrenal gland has been diagnosed in any of these patients. Genetic (molecular) tests performed in 31 out of 36 living patients revealed mutations of RET gene in 4 (12.9%). PMID: 11130252 [PubMed - indexed for MEDLINE] NR221: Oncogene. 2000 Nov 23;19(50):5729-35. The TRK-T1 fusion protein induces neoplastic transformation of thyroid epithelium. Russell JP, Powell DJ, Cunnane M, Greco A, Portella G, Santoro M, Fusco A, Rothstein JL. Department of Otolaryngology, Head & Neck Surgery, Kimmel Cancer Institute, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA. Genetic analysis of human papillary thyroid carcinomas (PTC) has revealed unique chromosomal translocations that form oncogenic fusion proteins and promote thyroid tumorigenesis in up to 60% of tumors examined. Although, the majority of thyroid specific translocations involve the growth factor receptor c-RET, variant rearrangements of the receptor for nerve growth factor, NTRK1 have also been described. One such translocation, TRK-T1, forms a fusion protein composed of the carboxyl terminal tyrosine kinase domain of NTRK1 and the amino terminal portion of TPR (Translocated Promoter Region). To determine if TRK-T1 expression can cause thyroid cancer in vivo, we developed transgenic mice that express the human TRK-T1 fusion protein in the thyroid. Immunohistochemical analysis of TRK-T1 transgenic mouse thyroids revealed TRK-T1 staining within the thyroid follicular epithelium. In contrast to nontransgenic littermates, 54% of transgenic mice developed thyroid abnormalities that included follicular hyperplasia and papillary carcinoma. Furthermore, all transgenic mice examined greater than 7 months of age developed thyroid hyperplasia and/or carcinoma. These data support the conclusion that TRK-T1 is oncogenic in vivo and contributes to the neoplastic transformation of the thyroid. PMID: 11126359 [PubMed - indexed for MEDLINE] NR222: J Biol Chem. 2001 Mar 23;276(12):9344-51. Epub 2000 Dec 14. Human glial cell line-derived neurotrophic factor receptor alpha 4 is the receptor for persephin and is predominantly expressed in normal and malignant thyroid medullary cells. Lindahl M, Poteryaev D, Yu L, Arumae U, Timmusk T, Bongarzone I, Aiello A, Pierotti MA, Airaksinen MS, Saarma M. Program in Molecular Neurobiology, Institute of Biotechnology, Viikki Biocenter, University of Helsinki, FIN-00014 Helsinki, Finland. Glial cell line-derived neurotrophic factor (GDNF) family ligands signal through receptor complex consisting of a glycosylphosphatidylinositol-linked GDNF family receptor (GFR) alpha subunit and the transmembrane receptor tyrosine kinase RET. The inherited cancer syndrome multiple endocrine neoplasia type 2 (MEN2), associated with different mutations in RET, is characterized by medullary thyroid carcinoma. GDNF signals via GFRalpha1, neurturin via GFRalpha2, artemin via GFRalpha3, whereas the mammalian GFRalpha receptor for persephin (PSPN) is unknown. Here we characterize the human GFRalpha4 as the ligand-binding subunit required together with RET for PSPN signaling. Human and mouse GFRalpha4 lack the first Cys-rich domain characteristic of other GFRalpha receptors. Unlabeled PSPN displaces (125)I-PSPN from GFRA4-transfected cells, which express endogenous Ret. PSPN can be specifically cross-linked to mammalian GFRalpha4 and Ret, and is able to promote autophosphorylation of Ret in GFRA4-transfected cells. PSPN, but not other GDNF family ligands, promotes the survival of cultured sympathetic neurons microinjected with GFRA4. We identified different splice forms of human GFRA4 mRNA encoding for two glycosylphosphatidylinositol-linked and one putative soluble isoform that were predominantly expressed in the thyroid gland. Overlapping expression of RET and GFRA4 but not other GFRA mRNAs in normal and malignant thyroid medullary cells suggests that GFRalpha4 may restrict the MEN2 syndrome to these cells. PMID: 11116144 [PubMed - indexed for MEDLINE] DR223: Oncogene. 2000 Nov 20;19(49):5590-7. The RET proto-oncogene in human cancers. Jhiang SM. Department of Physiology and Cell Biology, The Ohio State University, Columbus, Ohio, OH 43210, USA. The activation of the RET proto-oncogene contributes to the development of human cancers in two different ways. Somatic rearrangements of RET with a variety of activating genes, which contribute to unscheduled expression and constitutive dimerization of the chimeric RET/PTC oncoproteins in thyroid follicular cells, are frequently found in radiation-induced papillary thyroid carcinomas. Germ-line mutations, mainly point mutations, that lead to constitutive activation of RET tyrosine kinase activity are responsible for the development of the inherited cancer syndrome, multiple endocrine neoplasia type 2. There appears to be a correlation between specific types of RET mutation and clinical phenotypes of the cancers involved. The biological effects and the signaling pathways induced by different forms of RET activation have been investigated in a variety of cultured cells as well as in genetically engineered animal models. The identification of RET mutations in most MEN 2 families (95%) has translated into improved care for MEN 2 patients. However, further investigation of the signaling pathways contributing to tumorigenesis in relevant tissues will eventually help us to develop novel strategies to prevent or to treat human papillary thyroid carcinomas, MEN 2 disease, as well as the sporadic cancers relevant to MEN 2 disease. Publication Types: Review Review, Tutorial PMID: 11114739 [PubMed - indexed for MEDLINE] DR224: Surgery. 2000 Dec;128(6):1052-7;discussion 1057-8. Update on the MEN 2A c804 RET mutation: is prophylactic thyroidectomy indicated? Frohnauer MK, Decker RA. Department of Endocrinology, Maine Medical Center, Portland, ME, USA. BACKGROUND: Mutations of the RET proto-oncogene co-segregate with multiple endocrine neoplasia type 2A. A rare sequence abnormality at codon 804 (c804) has been reported in 6 kindreds and linked to mild C-cell disease, which raises the question of the appropriateness of thyroidectomy in childhood. The purpose of this study was to (1) report the clinical correlates of 5 additional c804 kindreds, and (2) clarify therapeutic options in children. METHODS: Thirty-eight members from five c804 kindreds underwent genetic analysis. Biochemical, operative, and pathology reports were reviewed. RESULTS: Twenty-three gene carriers were identified, of whom 14 had thyroidectomy. Medullary thyroid carcinoma was found in 7 patients (aged 5-56 years), C-cell hyperplasia in 6 patients (aged 13-40 years), and normal histology in a single patient (aged 27 years). One patient with medullary thyroid carcinoma died of metastases (aged 12 years). Nine of the 23 gene carriers delayed operation, 4 of whom had calcitonin testing. Three of the 4 patients had abnormal calcitonin levels and a single patient was negative (aged 40 years). Of the remaining 9 patients, 2 await thyroidectomy, and 3 have refused evaluation. CONCLUSIONS: Penetrance of the c804 mutation is highly variable. Medullary thyroid carcinoma associated with this genotype has aggressive potential. Prophylactic thyroidectomy in childhood is a viable approach. PMID: 11114642 [PubMed - indexed for MEDLINE] DR225: J Med Genet. 2000 Nov;37(11):817-27. Multiple endocrine neoplasia type 2 and RET: from neoplasia to neurogenesis. Hansford JR, Mulligan LM. Department of Pathology, Queen's University, Kingston, Ontario K7L 3N6, Canada. Multiple endocrine neoplasia type 2 (MEN 2) is an inherited cancer syndrome characterised by medullary thyroid carcinoma (MTC), with or without phaeochromocytoma and hyperparathyroidism. MEN 2 is unusual among cancer syndromes as it is caused by activation of a cellular oncogene, RET. Germline mutations in the gene encoding the RET receptor tyrosine kinase are found in the vast majority of MEN 2 patients and somatic RET mutations are found in a subset of sporadic MTC. Further, there are strong associations of RET mutation genotype and disease phenotype in MEN 2 which have led to predictions of tissue specific requirements and sensitivities to RET activity. Our ability to identify genetically, with high accuracy, subjects with MEN 2 has revolutionised our ability to diagnose, predict, and manage this disease. In the past few years, studies of RET and its normal ligand and downstream interactions and the signalling pathways it activates have clarified our understanding of the roles played by RET in normal cell survival, proliferation, and differentiation, as well as in disease. Here, we review the current knowledge of the normal functions of RET and the effects of mutations of this gene in tumorigenesis and in normal development. Publication Types: Review Review, Tutorial PMID: 11073534 [PubMed - indexed for MEDLINE] DR226: J Clin Endocrinol Metab. 2000 Oct;85(10):3898-907. Tyrosines 1015 and 1062 are in vivo autophosphorylation sites in ret and ret-derived oncoproteins. Salvatore D, Barone MV, Salvatore G, Melillo RM, Chiappetta G, Mineo A, Fenzi G, Vecchio G, Fusco A, Santoro M. Centro di Endocrinologia ed Oncologia Sperimentale del Consiglio Nazionale delle Ricerche, Dipartimento di Biologia e Patologia Cellulare e Molecolare, Istituto Nazionale dei Tumori di Napoli, Naples, Italy. Point mutations of the RET receptor tyrosine kinase are responsible for the inheritance of multiple endocrine neoplasia (MEN) type 2 syndromes and are also present in a fraction of sporadic medullary thyroid carcinomas. Somatic rearrangements of the RET gene generating the chimeric RET/papillary thyroid carcinoma (PTC) oncogenes are the predominant molecular lesions associated with papillary carcinoma, the most frequent thyroid malignancy in humans. Oncogenic mutations cause constitutive activation of the kinase function of RET, which, in turn, results in the autophosphorylation of RET tyrosine residues critical for signaling. In vitro kinase assays previously revealed six putative RET autophosphorylation sites. The aim of the present study was to assess the phosphorylation of two such residues, tyrosines 1015 and 1062 (Y1015 and Y1062), in the in vivo signaling of RET and RET-derived oncogenes. Using phosphorylated RET-specific antibodies, we demonstrate that both Y1015 and Y1062 are rapidly phosphorylated upon ligand triggering of RET. Moreover, regardless of the nature of the underlying activating mutation, the concomitant phosphorylation of Y1015 and Y1062 is a common feature of the various oncogenic RET products (MEN2A, MEN2B, and PTC). This study shows that Ab-pY1062 is a useful tool with which to detect activated RET in human tumor cells and surgical samples. Finally, the microinjection of Ab-pY1062 antibodies into living cells demonstrates that Ret/PTC1 signaling is required to maintain the mitogenesis of a human carcinoma cell line expressing the Ret/PTC1 oncoprotein. PMID: 11061555 [PubMed - indexed for MEDLINE] DR227: World J Surg. 2000 Nov;24(11):1367-72. Unilateral surgery supported by germline RET oncogene mutation analysis in patients with sporadic medullary thyroid carcinoma. Miyauchi A, Matsuzuka F, Hirai K, Yokozawa T, Kobayashi K, Kuma S, Kuma K, Futami H, Yamaguchi K. Kuma Hospital, 8-2-35 Shimoyamate-dori, Chuo-ku, Kobe 650-0011, Japan. miyauchi@kuma-h.or.jp Compared to hereditary medullary thyroid carcinoma (MTC), sporadic MTC tends to be unicentric and confined to one lobe. Patients with sporadic MTC usually undergo total thyroidectomy because of a possible hereditary or bilateral process. We evaluated the usefulness of germline RET oncogene mutation analysis in surgery for apparently sporadic MTC and performed unilateral surgery on patients without detectable mutation. In 36 patients with a preoperative diagnosis of apparently sporadic MTC, we performed germline RET oncogene mutation analyses: before surgery in 8 recent patients and after surgery in 28 who had been treated before 1996. Of the latter, 5 had bilateral MTC. DNA samples were extracted from their peripheral blood, and the polymerase chain reaction products of the RET proto-oncogene were analyzed using single-strand conformation polymorphism analysis and the direct sequencing methods. Before 1996 we often performed total thyroidectomy but changed to hemithyroidectomy thereafter, except in one patient with associated Graves' ophthalmopathy. Our minimal standard practice included systematic central and ipsilateral neck dissection. The outcome was assessed in terms of gastrin- and calcium-stimulated plasma calcitonin levels. Germline RET mutations were found in six patients. Five of these patients had bilateral MTC, whereas all 30 patients without mutation had unilateral disease. Hemithyroidectomy in seven of our recent patients resulted in normalization of plasma calcitonin levels in all, although four were found to have microscopic lymph node involvement. In conclusion, hemithyroidectomy with systematic central and ipsilateral neck dissection is an appropriate procedure for patients with sporadic MTC without detectable germline RET mutations. PMID: 11038208 [PubMed - indexed for MEDLINE] DR228: Virchows Arch. 2000 Sep;437(3):256-63. Regulation of proliferation and apoptosis in sporadic and hereditary medullary thyroid carcinomas and their putative precursor lesions. Hinze R, Gimm O, Taubert H, Bauer G, Dralle H, Holzhausen HJ, Rath FW. Martin-Luther-University of Halle-Wittenberg, Faculty of Medicine, Institute of Pathology, Halle, Germany. raoul.hinze@medizin.uni-halle.de C-cell hyperplasia (CCH) and medullary thyroid carcinoma (MTC) in patients affected by germline mutations of the RET oncogene represent an exceptional opportunity to study the regulation of proliferation and apoptosis during tumour initiation and progression. In 56 specimens [CCH, n=1; MTC with CCH, n=26; MTC, n=20; lymph-node metastasis (LNM), n=9] from 46 patients [multiple endocrine neoplasia type 2a (MEN2a), n=24; MEN2b, n=2; familiar MTC (FMTC), n=4; sporadic MTC, n-16] and 3 cases of non-neoplastic CCH, proliferation activity (MIB1), the rate of apoptosis [dUTP nick end labelling (TUNEL)] and expression of p53, bcl-2, bcl-x and bax were investigated and compared with clinical data. In MEN-associated CCH and small MTC, bcl-2 was strongly expressed, bcl-x was moderately expressed and bax was only weakly expressed. Advanced tumours and LNM did show a more heterogeneous bcl-2 staining accompanied by an increased bax expression and accelerated proliferation. The rate of apoptosis was extremely low in all investigated tumours. P53 was detectable in three patients with rapidly growing and extensively metastasising MTC. No somatic p53 mutations were found. Hereditary MTC with germline RET mutations at codon 918 (MEN2b) and codon 634 revealed a bias towards a higher proliferation activity at a younger age and are more frequently accompanied by LNM. CCH and MTC are characterised with a preponderance of bcl-2 as a factor blocking the programmed cell death. While MTC, in general, is a slowly growing tumour, a minority of tumours do progress rapidly with high proliferation. The factors leading to an accelerated tumour progression do not seem to take their effect via the regulation of apoptosis. Certain alterations of RET are supposed to have a direct or indirect implication on proliferation and, because of this, an effect on the clinical course. PMID: 11037345 [PubMed - indexed for MEDLINE] DR229: Science. 2000 Oct 6;290(5489):138-41. Comment in: Science. 2000 Oct 6;290(5489):62-3. Proximity of chromosomal loci that participate in radiation-induced rearrangements in human cells. Nikiforova MN, Stringer JR, Blough R, Medvedovic M, Fagin JA, Nikiforov YE. Department of Pathology and Laboratory Medicine, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA. Rearrangements involving the RET gene are common in radiation-associated papillary thyroid cancer (PTC). The RET/PTC1 type of rearrangement is an inversion of chromosome 10 mediated by illegitimate recombination between the RET and the H4 genes, which are 30 megabases apart. Here we ask whether despite the great linear distance between them, RET and H4 recombination might be promoted by their proximity in the nucleus. We used two-color fluorescence in situ hybridization and three-dimensional microscopy to map the positions of the RET and H4 loci within interphase nuclei. At least one pair of RET and H4 was juxtaposed in 35% of normal human thyroid cells and in 21% of peripheral blood lymphocytes, but only in 6% of normal mammary epithelial cells. Spatial contiguity of RET and H4 may provide a structural basis for generation of RET/PTC1 rearrangement by allowing a single radiation track to produce a double-strand break in each gene at the same site in the nucleus. PMID: 11021799 [PubMed - indexed for MEDLINE] DR230: Cancer Res. 2000 Sep 15;60(18):5254-60. Tissue-specific carcinogenesis in transgenic mice expressing the RET proto-oncogene with a multiple endocrine neoplasia type 2A mutation. Kawai K, Iwashita T, Murakami H, Hiraiwa N, Yoshiki A, Kusakabe M, Ono K, Iida K, Nakayama A, Takahashi M. Department of Pathology, Nagoya University School of Medicine, Japan. Germ line mutations of the RET proto-oncogene are responsible for the development of multiple endocrine neoplasia type 2A (MEN 2A), an inherited cancer syndrome characterized by medullary thyroid carcinoma, pheochromocytoma, and parathyroid hyperplasia. To study the mechanism of tissue-specific tumor development by RET with a MEN2A (cysteine 634-->arginine) mutation, we generated transgenic mice by introducing the RET-MEN2A gene fused to Moloney murine leukemia virus long terminal repeat. Expression of the transgene and its product was detected at variable levels in a variety of tissues including thyroid, heart, liver, colon, parotid gland, and brain. All of 29 mice analyzed developed thyroid C-cell hyperplasia or medullary carcinoma, accompanying high levels of serum calcitonin. In addition, development of mammary or parotid gland adenocarcinoma was observed in one-half of the transgenic mice. RET dimerization and its complex formation with Shc and Grb2 adaptor proteins were detected in tumor tissues. Unexpectedly, no tumor formation was found in other tissues despite RET-MEN2A expression where RET dimerization was undetectable. Because these tissues but not tumors expressed glial cell line-derived neurotrophic factor family receptor alpha (GFR alpha) at high levels, this suggested that GFR alpha expression may interfere in the dimerization of the RET-MEN2A mutant proteins, leading to tissue-specific tumor development in vivo. PMID: 11016655 [PubMed - indexed for MEDLINE] NR231: Am J Med Genet. 2000 Sep 4;94(1):19-27. Familial form of hirschsprung disease: nucleotide sequence studies reveal point mutations in the RET proto-oncogene in two of six families but not in other candidate genes. Munnes M, Fanaei S, Schmitz B, Muiznieks I, Holschneider AM, Doerfler W. Institute of Genetics, University of Cologne, Koeln, Germany. Hirschsprung disease (HSCR; McKusick 142623) or aganglionic megacolon is a frequent (1 in 5,000 live births) heritable disorder of the enteric nervous system. By haplotyping with a variety of microsatellite markers, by amplifying all 20 exons of the RET proto-oncogene and by applying a direct DNA sequencing protocol, we have analyzed the DNA from HSCR patients in 6 different families. In one family with a joint occurrence of HSCR and FMTC (follicular medullary thyroid carcinoma), we have identified a mutation in codon 609 in one out of 6 cysteine residues encoded in exon 10 of the RET gene. This C609R point mutation has not previously been reported to cause HSCR. In 2 of the HSCR patients described here from different families, we have found a mutation in exon 2 (R77C) and a silent mutation in exon 3 (Y204Y), respectively, in the extracellular part of the RET proto-oncogene. In introns 2 and 17 of the RET proto-oncogene in 2 families, we have detected single nucleotide exchanges that are probably polymorphisms with unknown, if any, relations to HSCR. The DNA sequences of 5 further genes (GDNF, GDNFRalpha, EDN3, EDNRB, and NTN), that may contribute to the development of HSCR, have not shown mutations in the patients analyzed so far. In 2 of the reported families with several affected children and one grandchild, sequence analyses revealed no mutations in the coding regions of any of the candidate genes analyzed. Copyright 2000 Wiley-Liss, Inc. PMID: 10982477 [PubMed - indexed for MEDLINE] DR232: Oncogene. 2000 Aug 31;19(37):4236-42. RET/PCM-1: a novel fusion gene in papillary thyroid carcinoma. Corvi R, Berger N, Balczon R, Romeo G. International Agency for Research on Cancer, 150 cours Albert Thomas, 69372 Lyon, France. The RET proto-oncogene is often activated through somatic rearrangements in papillary thyroid carcinomas (PTCs). Three main rearranged forms of RET have been described: RET/PTC1 and RET/PTC3, which arise from a paracentric inversion and RET/PTC2, which originates from a 10 : 17 translocation. We previously developed a dual-color FISH test to detect these RET rearrangements in interphase nuclei of thyroid lesions. This approach allowed us to detect a novel translocation involving the RET region, which was not detectable by RT - PCR with specific primers for known rearrangements. A combination of RT - PCR and RACE analyses finally led to the identification of the fusion gene, which involves the 5' portion of PCM-1, a gene coding for a centrosomal protein with distinct cell cycle distribution, and the RET tyrosine kinase (TK) domain. FISH analysis confirmed the chromosomal localization of PCM-1 on chromosome 8p21-22, a region commonly deleted in several tumors. Immunohistochemistry, using an antibody specific for the C-terminal portion of PCM-1 showed that the protein level is drastically decreased and its subcellular localization is altered in thyroid tumor tissue with respect to normal thyroid. However, heterozygosity is retained for seven microsatellite markers in the 8p21-22 region, suggesting that the non-rearranged PCM-1 allele is not lost and that the translocation is balanced. Oncogene (2000) 19, 4236 - 4242 PMID: 10980597 [PubMed - indexed for MEDLINE] DR233: J Hypertens. 2000 Aug;18(8):1019-23. Incidence and clinical relevance of RET proto-oncogene germline mutations in pheochromocytoma patients. Januszewicz A, Neumann HP, Lon I, Szmigielski C, Symonides B, Kabat M, Apel TW, Wocial B, Lapinski M, Januszewicz W. Department of Hypertension, Institute of Cardiology, Warsaw, Poland. BACKGROUND: Autosomal dominant cancer syndrome--multiple endocrine neoplasia type 2 (MEN 2), may exist more often than expected in patients with pheochromocytoma. Germline mutations identified recently in MEN 2 can be revealed by genetic screening. OBJECTIVE: To evaluate the frequency of RET (rearranged during transfection) mutations in patients with pheochromocytoma. DESIGN AND METHODS: We genetically screened germline mutations in the RET proto-oncogene and clinically re-evaluated patients with pheochromocytoma. A pentagastrin test and other biochemical studies were performed in all patients. SETTING: Department of Internal Medicine and Hypertension, The Medical University of Warsaw, Warsaw, Poland and the Department of Nephrology and Hypertension, Albert Ludwigs University, Freiburg, Germany. PARTICIPANTS: Seventy seven unselected patients with pheochromocytoma (19 men, 58 women, mean age: 51.55 +/- 1.5 years; pheochromocytoma confirmed histopathologically) out of 162 diagnosed and treated in the years 1957-1998 in the Department of Internal Medicine and Hypertension in Warsaw, Poland. The other 85 patients did not respond to the written invitation. MAIN OUTCOME MEASURES: The finding of RET mutations and diagnosis of MEN 2 in patients with pheochromocytoma. RESULTS: Genetic testing revealed germline mutations in the RET proto-oncogene in six patients (7.8%). All carriers had mutation of exon 11, codon 634: TGC to CGC. In four patients with this mutation, medullary thyroid carcinoma (MIC) was diagnosed and in three cases, surgically treated. Biochemical parameters: parathormone 31.88 +/- 2.87 pg/ml, calcitonin: 0 min 0.23 +/- 0.14 ng/ml; 2 min 0.49 +/- 0.21 ng/ml; 5 min 0.48 +/- 0.21 ng/ml, metoxycatecholamines: 601.62 +/- 42.71 microg/24h, epinephrine: 1.94 +/- 0.17 microg/24h, norepinephrine 13.96 +/- 1.3 microg/24h, carcinoembryonic antigen (CEA) 9.94 +/- 4.3 ng/ml. Ambulatory blood pressure monitoring (ABPM): systolic blood pressure (SBP): 116 +/- 1.9 mmHg, diastolic blood pressure (DBP): 73.7 +/- 0.9 mmHg. Clinical, biochemical and imaging procedures did not reveal any recurrence of pheochromocytoma in the 77 patients studied. CONCLUSIONS: Patients with pheochromocytoma should be genetically screened for mutations of the RET proto-oncogene. These patients should undergo clinical screening for MEN 2. In addition, genetic studies can be useful for the screening of the families of the carriers. PMID: 10953992 [PubMed - indexed for MEDLINE] DR234: Cancer. 2000 Aug 15;89(4):863-7. Is thyroidectomy necessary in RET mutations carriers of the familial medullary thyroid carcinoma syndrome? Hansen HS, Torring H, Godballe C, Jager AC, Nielsen FC. Department of Oncology, Rigshospitalet, Copenhagen, Denmark. BACKGROUND: The results and consequences of genetic testing in a family with familial medullary thyroid carcinoma (FMTC) are described. METHODS: In the screening of relatives, serum calcitonin is replaced by RET mutation analysis that was performed in families suspected of hereditary medullary thyroid carcinoma (MTC). In 4 of 10 families, mutation in exon 10 was found in codon 611. RESULTS: One hundred fifty persons belonging to 30 families were tested, of which 10 families were carriers of RET mutation in exon 10. In 1 of these families with MTC only, 2 brothers were gene carriers of a RET codon 611 mutation and lived without any sign of MTC. One is aged 79 years, and the other died at the age of 71 of other causes. CONCLUSIONS: The results indicate that the gene carrier in families with MTC without other endocrine tumors (FMTC) exhibits a highly variable disease course. A 611 codon mutation is most often a rather mild and slow progression form of MTC. Because 2 gene carriers were still alive at age 70 years without showing any sign of the disease, it is tempting to ask if all gene carriers with a 611 codon mutation without other endocrine tumors should be operated on, and if so, at what age? In the authors' opinion, more information is needed to be able to answer these questions. The current guidelines for treatment of patients with hereditary MTC are discussed. Copyright 2000 American Cancer Society. PMID: 10951350 [PubMed - indexed for MEDLINE] DR235: Gene Expr. 1999;8(5-6):311-26. Glucocorticoids differentially inhibit expression of the RET proto-oncogene. Capes-Davis A, Andrew SD, Hyland VJ, Twigg S, Learoyd DL, Dwight T, Marsh DJ, Robinson BG. Kolling Institute of Medical Research and Department of Endocrinology, Royal North Shore Hospital, University of Sydney, N.S.W., Australia. The RET proto-oncogene encodes a receptor tyrosine kinase activated by the binding of factors from the glial cell line-derived neurotrophic factor (GDNF) family to receptor-alpha components such as GDNF family receptor alpha-1 (GFR alpha-1). Mutations within the sequence of the RET proto-oncogene are associated with multiple endocrine neoplasia type 2 (MEN 2), an inherited tumor syndrome characterized by the development of medullary thyroid carcinoma (MTC) and other neuroendocrine tumors. Despite Northern analysis showing that RET is expressed in the majority of MTCs, the factors regulating this expression are poorly understood. To address this issue we examined RET expression in response to glucocorticoids in the TT cell line, derived from a metastatic MTC. The synthetic glucocorticoid dexamethasone was found to reduce RET expression at both mRNA and protein levels. This effect was dose responsive and maximal at 24 h. The reduction in RET mRNA was shown to be specific to glucocorticoids and was also seen in a primary MTC culture. Nuclear run-on studies revealed the reduction in steady-state RNA to be due to a decrease in RET mRNA transcription and the effect was shown to be independent of new protein synthesis or RNA stability. Dexamethasone was also found to exert an inhibitory effect upon cell growth, suggesting a potential use for glucocorticoids in the treatment of medullary carcinoma and MEN 2. PMID: 10947080 [PubMed - indexed for MEDLINE] DR236: J Clin Endocrinol Metab. 2000 Aug;85(8):2733-9. Prevalence and distribution of ret/ptc 1, 2, and 3 in papillary thyroid carcinoma in New Caledonia and Australia. Chua EL, Wu WM, Tran KT, McCarthy SW, Lauer CS, Dubourdieu D, Packham N, O'Brien CJ, Turtle JR, Dong Q. Department of Medicine, University of Sydney, New South Wales, Australia. The world's highest incidence of thyroid cancer has been reported among females in New Caledonia, a French overseas territory in the Pacific located between Australia and Fiji. To date, no molecular genetic studies in this population are available. Over the past few years, the oncogenic rearrangement of the ret protooncogene (ret/ptc) has been studied in papillary carcinomas in different populations. In this study, we investigated the prevalence and distribution of ret/ptc1, 2, and 3 in papillary thyroid carcinoma from the New Caledonian population and compared the pattern with that of an Australian population. Fresh-frozen and paraffin-embedded papillary carcinomas from 27 New Caledonian and 20 Australian patients were examined for ret rearrangements by means of RT-PCR with primers flanking the chimeric region, followed by hybridization with radioactive probes. ret/ptc was present in 70% of the New Caledonian and in 85% of the Australian samples. Multiple rearrangements were detected and confirmed by sequencing in 19 cases, 4 of which had 3 types of rearrangements in the same tumor. This study demonstrates a high prevalence of ret/ptc in New Caledonian and Australian papillary carcinoma. The findings of multiple ret/ptc in the same tumor suggest that some thyroid neoplasms may indeed be polyclonal. PMID: 10946873 [PubMed - indexed for MEDLINE] NR237: Digestion. 2000;62 Suppl 1:3-18. Molecular genetics of neuroendocrine tumors. Calender A. Department of Genetics and Cancer, Hopital Edouard-Herriot, Lyon, France. calender@univ-lyon1.fr Through insights into the molecular genetics of neuroendocrine tumors (NETs), the genes predisposing to multiple endocrine neoplasia (MEN) syndromes were identified. In MEN1, tumors occur in the parathyroids, endocrine pancreas, anterior pituitary, adrenal glands and thymic neuroendocrine tissues. The MEN1 gene encodes a putative growth-suppressor protein, menin, binding JunD, a transcriptional factor belonging to the AP-1 complex. However, new partners binding menin remain to be found. The MEN1 gene might be involved in 1-50% of sporadic NETs. Another critical mechanism involved in NETs is the deregulation of the RET-signalling pathways by oncogenic point mutations responsible for MEN2 syndromes. MEN2 refers to the inherited forms of medullary thyroid carcinoma. The RET proto-oncogene, a tyrosine-kinase receptor, is activated by missense mutations occurring either in the extracellular dimerization domain or intracellular tyrosine kinase catalytic regions. In both cases the receptor is constitutionally activated in the absence of natural ligands. Endocrine tumors also belong to the clinical pattern of Recklinghausen (NF1) and von Hippel-Lindau (VHL) diseases. The genes for both syndromes have been characterized and provide new pathways for endocrine tumorigenesis related to G-protein physiology (NF1) and transcriptional regulation and/or endothelial cell proliferation (VHL), respectively. Here, we propose a basic overview of recent data on genetic events leading a normal endocrine cell towards a fully malignant phenotype. Copyright 2000 S. Karger AG, Basel Publication Types: Review PMID: 10940682 [PubMed - indexed for MEDLINE] DR238: Clin Endocrinol (Oxf). 2000 Jul;53(1):131-6. New breakpoints in both the H4 and RET genes create a variant of PTC-1 in a post-Chernobyl papillary thyroid carcinoma. Elisei R, Romei C, Soldatenko PP, Cosci B, Vorontsova T, Vivaldi A, Basolo F, Cherstvoy ED, Pinchera A, Pacini F. Department of Endocrinology and Metabolism, University of Pisa, Italy. relisei@endoc.med.unipi.it Two main types of RET/PTC oncogene, named RET/PTC-1 and 3, occur in papillary thyroid carcinomas especially in those from Belarus children after the Chernobyl nuclear accident. Several variants of RET/PTC-3 have also been found, having different break points with respect to the classical RET/PTC-3. To our knowledge, no variant of RET/PTC-1 has been described up to now. We found a post-Chernobyl papillary thyroid carcinoma with an RET/PTC-1 rearrangement characterized by a transcript longer than expected. Sequence analysis of the PCR product obtained after RT-PCR revealed new fusion points between H4 and RET genes. The genomic sequence showed new breakpoints in both H4 intronic and in RET exonic regions. The RET gene breakpoint occurred within exon 11, at variance with the classical form of RET/PTC-1, in which it is in intron 11. As a consequence of this new fusion point, the transcript included 132 nucleotides of exon 11, coding for 44 amino acids of RET protein. Regarding the H4 gene, the classical breakpoint is in the first intron and the cDNA contains a fragment of 339 nucleotides. In our case the cDNA had a longer fragment of H4 involving a total of 1266 nucleotides. Sequencing of genomic DNA revealed a rearrangement breakpoint at position 886 of a new H4 intron located downstream of the 1266 coding region. Furthermore, as a consequence of the activation of a cryptic splicing site, 132 nucleotides of this intron were spliced between the H4 and RET genes. Sequence analysis of the new chimera showed that the original frames of H4 and RET were joint with the intronic sequence without disruption of the open reading frame (ORF). Moreover, the genomic DNA of this case showed transforming activity in the DNA-mediated transfection assay using NIH-3T3 cells. In conclusion, we describe here the first variant of RET/PTC-1 oncogene, which we have termed 'long'-PTC-1, characterized by new breakpoints of both genes involved in the rearrangement and having transforming activity. Similar to previously reported PTC-3 variants, long-PTC-1 has been found in a post-Chernobyl papillary thyroid carcinoma confirming that RET/PTC rearrangements other than the classical forms (RET/PTC-1 and -3) are specifically associated with radiation-induced papillary thyroid cancer. Publication Types: Case Reports PMID: 10931090 [PubMed - indexed for MEDLINE] DR239: Cancer Res. 2000 Jul 15;60(14):3727-31. Tyrosine 1062 of RET-MEN2A mediates activation of Akt (protein kinase B) and mitogen-activated protein kinase pathways leading to PC12 cell survival. De Vita G, Melillo RM, Carlomagno F, Visconti R, Castellone MD, Bellacosa A, Billaud M, Fusco A, Tsichlis PN, Santoro M. Centro di Endocrinologia ed Oncologia Sperimentale del Consiglio Nazionale delle Richerche, Dipartimento di Biologia e Patologia Cellulare e Molecolare, Naples, Italy. The RET tyrosine kinase is a functional receptor for neurotrophic ligands of the glial cell line-derived neurotrophic factor (GDNF) family. Loss of function of RET is associated with congenital megacolon or Hirschsprung's disease, whereas germ-line point mutations causing RET activation are responsible for multiple endocrine neoplasia type 2 (MEN2A, MEN2B, and familial medullary thyroid carcinoma) syndromes. Here we show that the expression of a constitutively active RET-MEN2A oncogene promotes survival of rat pheochromocytoma PC12 cells upon growth factor withdrawal. Moreover, we show that the RET-MEN2A-mediated survival depends on signals transduced by the phosphoinositide 3-kinase (PI3K) and mitogen-activated protein kinase (MAPK) cascades. Thus, in PC12 cells, RET-MEN2A associates with the PI3K regulatory subunit p85 and promotes activation of Akt (also referred to as protein kinase B) in a PI3K-dependent fashion; in addition, RET-MEN2A promotes MAPK activation. PI3K recruitment and Akt activation as well as MAPK activation depend on RET-MEN2A tyrosine residue 1062. As a result, tyrosine 1062 of RET-MEN2A is essential for RET-MEN2A-mediated survival of PC12 cells cultured in growth factor-depleted media. PMID: 10919641 [PubMed - indexed for MEDLINE] DR240: Nippon Rinsho. 2000 Jul;58(7):1437-41. [Multiple endocrine neoplasia type 2; MEN 2] [Article in Japanese] Matsuura K, Araki K. Department of Surgery, Kochi Medical School. Multiple endocrine neoplasia type 2 (MEN 2) is an inherited disorder as an autosomal dominant trait, characterized by medullary thyroid carcinoma (MTC). MEN 2 is classified with associated diseases into three subtypes: MEN 2A, MEN 2B and familial MTC. It has recently been shown to be associated with germline mutation in the RET proto-oncogene. Genetic testing allows easily for accurate diagnosis of presymptomatic gene carriers and surgical treatment at an early stage of the disease. In this review we delivered the classification, clinical feature, mutation in RET, mutation analysis, and management of MEN 2, and we discuss recent progress of research on the molecular basis and how genetic testing could be used for clinical management of affected patients or individuals in at-risk families. Publication Types: Review Review, Tutorial PMID: 10921320 [PubMed - indexed for MEDLINE] NR241: Cancer Res. 2000 Jul 1;60(13):3592-8. Fusion of H4/D10S170 to the platelet-derived growth factor receptor beta in BCR-ABL-negative myeloproliferative disorders with a t(5;10)(q33;q21). Kulkarni S, Heath C, Parker S, Chase A, Iqbal S, Pocock CF, Kaeda J, Cwynarski K, Goldman JM, Cross NC. Department of Haematology, Imperial College School of Medicine Hammersmith Hospital, London, United Kingdom. We have studied a patient who presented with clinical features suggestive of chronic myeloid leukemia in accelerated phase. BCR-ABL transcripts were undetectable by reverse transcription-PCR, but a novel reciprocal translocation, t(5;10)(q33;q21.2), was seen by standard cytogenetic analysis. Chromosome band 5q33 contains the gene encoding the platelet-derived growth factor beta receptor (PDGFbetaR), the receptor tyrosine kinase that is disrupted by the t(5;7), t(5;12), and t(5;14) in myeloid disorders, resulting in the fusion of PDGFbetaR to HIP1, TEL/ETV6, and CEV14, respectively. Southern analysis with PDGFbetaR cDNA revealed novel bands in patient but not control DNA after digestion with several restriction enzymes, indicating that this gene is also targeted by the t(5;10). Fluorescence in situ hybridization analysis of chromosome 5 indicated that a small inversion at 5q33 had taken place in addition to the interchromosomal translocation. The site of the chromosome 10 breakpoint fell within YAC 940e4. Because all PDGFbetaR fusions described thus far result in splicing to a common exon of this gene, we performed 5'-rapid amplification of cDNA ends PCR on patient RNA. Several clones were isolated in which PDGFbetaR fused in frame to H4/D10S170, a previously described ubiquitously expressed gene that is fused to the ret protein tyrosine kinase to form the PTC-1 oncogene in approximately 20% of papillary thyroid carcinomas. The presence of H4-PDGFbetaR chimeric mRNA in the patient was confirmed by reverse transcription-PCR; reciprocal PDGFbeta1R-H4 transcripts were not detected. We conclude that t(5;10)(q33;q21.2) is a novel translocation in BCR-ABL-negative chronic myeloid leukemia and that this abnormality results in an H4-PDGFbetaR fusion gene. This finding further strengthens the association between myeloproliferative disorders and deregulated tyrosine kinases. Publication Types: Case Reports PMID: 10910073 [PubMed - indexed for MEDLINE] DR242: J Endocrinol Invest. 2000 May;23(5):328-38. RET proto-oncogene mutations in thyroid carcinomas: clinical relevance. Pacini F, Elisei R, Romei C, Pinchera A. Dipartimento di Endocrinologia e Metabolismo, Universita di Pisa, Italy. fpacini@endoc.med.unipi.it Different forms of RET mutations are found in papillary and medullary thyroid carcinomas. Rearrangements with other genes (RET/PTC oncogene) play a causative role in a significant proportion of papillary thyroid carcinomas. In this case, several factors influence the frequency and the type of RET/PTC, such as exposure to radiation, age and histological variant of the papillary tumor. On the other hand, the presence of the mutation does not seem to influence the biological behavior of the tumor or its response to conventional treatment modalities. In the setting of medullary thyroid cancer, germline RET point-mutations are implicated in the pathogenesis of virtually all hereditary forms and somatic point-mutations in nearly half of the sporadic forms. The clinical impact of this finding is that family members at-risk of hereditary MTC may be screened by genetic analysis, to distinguish those carrying or not-carrying the mutation. The last can be reassured on their status and relieved from further follow-up. Those with the mutation may be treated at a pre-clinical stage of the disease or even before the disease is started. The present review is focused on the clinical implication of RET gene mutations in thyroid cancer patients. Publication Types: Review Review, Tutorial PMID: 10882153 [PubMed - indexed for MEDLINE] NR243: J Pathol. 2000 Jul;191(3):264-8. RET is expressed but not mutated in extra-adrenal paragangliomas. de Krijger RR, van der Harst E, Muletta-Feurer S, Bruining HA, Lamberts SW, Dinjens WN, Roth J, Heitz PU, Komminoth P. Department of Pathology, Erasmus University and University Hospital, Rotterdam, The Netherlands. dekrijger@path.fgg.eur.nl This study has investigated the role of the RET proto-oncogene, which has been identified as the susceptibility gene for multiple endocrine neoplasia (MEN) type 2, in the development of sporadic and familial extra-adrenal paragangliomas. RET protein expression was analysed by immunohistochemistry. Subsequently, DNA extracted from 52 tumours of 44 patients was screened for somatic RET point mutations in exons 10, 11, and 13-16, where oncogenic mutations have recently been described in a subset of sporadic medullary thyroid carcinomas and phaeochromocytomas. The methods employed included non-isotopic polymerase chain reaction-based single strand conformation polymorphism (PCR-SSCP) analysis and heteroduplex gel electrophoresis, followed by direct sequencing of PCR products. RET protein expression was demonstrated in all ten paragangliomas tested. However, none of the familial or sporadic extra-adrenal paragangliomas contained somatic mutations in exons 10, 11, or 13-16 of the RET proto-oncogene, whereas control samples with known mutations in these exons exhibited the expected band shift, or yielded an additional band with retarded migration. Although paragangliomas exhibit RET protein expression, these data indicate that oncogenic RET proto-oncogene mutations do not appear to be generally important in the formation of sporadic paragangliomas. Copyright 2000 John Wiley & Sons, Ltd. PMID: 10878547 [PubMed - indexed for MEDLINE] DR244: Surgery. 2000 Jul;128(1):93-8. Variable expressivity of familial medullary thyroid carcinoma (FMTC) due to a RET V804M (GTG-->ATG) mutation. Feldman GL, Edmonds MW, Ainsworth PJ, Schuffenecker I, Lenoir GM, Saxe AW, Talpos GB, Roberson J, Petrucelli N, Jackson CE. Department of Medical Genetics, Henry Ford Hospital, the Center for Molecular Medicine and Genetics, Detroit, MI 48201, USA. BACKGROUND: Multiple endocrine neoplasia type 2 (MEN 2) and familial medullary thyroid carcinoma (FMTC) are autosomal dominantly inherited cancer syndromes that predispose to C-cell hyperplasia and MTC. MEN 2A and FMTC are caused by mutations in the RET proto-oncogene. METHODS: We used a multiplex polymerase chain reaction-based assay to screen exons 10, 11, 13, and 14 of RET for mutations in 2 families with FMTC. We correlated mutation status with calcitonin and pathologic studies to determine genotype-phenotype correlations. RESULTS: We identified a mutation in codon 804 in exon 14 (GTG-->ATG; V804M) in both families. An 86-year-old person who was a gene carrier and other individuals over age 70 who were suspected by pedigree analysis to be gene carriers had no overt clinical evidence of MTC. Four of 21 patients who underwent a thyroidectomy also had papillary thyroid cancer. One individual in each family had metastatic MTC at age 30 and 32 years, and all 26 people having thyroidectomies had either MTC or C-cell hyperplasia, leading us to continue to recommend prophylactic thyroidectomy for all identified patients who were gene carriers. CONCLUSIONS: Because of active MTC in younger members of these families, including metastases, we have continued to advocate thyroid surgery in mutation-positive individuals. While DNA diagnosis of gene carriers and subsequent genetic counseling was relatively straightforward, the acceptance of surgical recommendations was more difficult for some individuals. These families demonstrate that the search for RET mutations should include exons 13, 14, 15, and 16 in patients whose studies in exons 10 and 11 are negative. PMID: 10876191 [PubMed - indexed for MEDLINE] PR245: Oncogene. 2000 Jun 15;19(26):2996-3002. Tumorigenesis mediated by MET mutant M1268T is inhibited by dominant-negative Src. Nakaigawa N, Weirich G, Schmidt L, Zbar B. Laboratory of Immunobiology, NCI-Frederick Cancer Research and Development Center, Frederick, Maryland, MD 21702, USA. We recently described germline and somatic mutations in the MET gene associated with papillary renal carcinoma type 1. MET mutation M1268T was located in a codon highly conserved among receptor tyrosine kinases, and homologous to the codon mutated in multiple endocrine neoplasia type 2B, and many cases of sporadic medullary carcinoma of the thyroid gland (Ret M918T). Ret M918T and MET M1268T have previously been shown to be highly active in mouse NIH3T3 transformation assays, and to change the substrate specificity of the kinase. We studied the mechanism of transformation mediated by MET M1268T by analysing a clone, F4, derived from NIH3T3 cells transformed by MET M1268T. In contrast to NIH3T3 cells, F4 cells grew in suspension in tissue culture, and rapidly formed tumors in nude mice. We found that c-Src was constitutively bound to MET proteins in F4 cells, and that Src kinase activity was elevated. Transfection of dominant negative Src constructs into F4 cells eliminated the ability of F4 cells to grow in suspension culture and retarded the growth of F4 cells in vivo. The ability of transfected dominant negative Src constructs to inhibit the growth of F4 cells correlated with the inhibition of phosphorylation of paxillin and focal adhesion kinase. Transfection of dominant negative Src constructs into F4 cells had no effect on Grb2 binding or PLC gamma phosphorylation. The results suggest that c-Src participates in the tumorigenic phenotype induced in NIH3T3 cells by MET M1268T by signaling through focal adhesion kinase and paxillin. Oncogene (2000). PMID: 10871851 [PubMed - indexed for MEDLINE] DR246: Oncogene. 2000 Jun 22;19(27):3121-5. Multiple endocrine neoplasia type 2B mutation in human RET oncogene induces medullary thyroid carcinoma in transgenic mice. Acton DS, Velthuyzen D, Lips CJ, Hoppener JW. Department of Internal Medicine, University Medical Center Utrecht, P.O. Box 85500, 3508 GA Utrecht, The Netherlands. Multiple endocrine neoplasia type 2B (MEN 2B) is a familial cancer syndrome, in which the cardinal feature is medullary thyroid carcinoma (MTC), a malignant tumor arising from the calcitonin producing thyroid C-cells. MEN 2B is associated with a germline point mutation in the RET proto-oncogene, leading to a Met-->Thr substitution at codon 918 in the kinase domain, which alters the substrate specificity of the protein. We used the human calcitonin gene (CALC-I) promoter to generate transgenic mice expressing either the human RET oncogene with the MEN2B-specific 918 Met-->Thr mutation (CALC-MEN2B-RET) or the human non-mutated RET proto-oncogene (CALC-WT-RET) in the C-cells. At 20 - 22 months of age three out of eight CALC-MEN2B-RET transgenic founders presented with macroscopic bilateral MTC. In two founders nodular C-cell hyperplasia (CCH) was observed. Thyroid abnormalities were never observed in CALC-WT-RET transgenic mice or control non-transgenic mice analysed at this age. In some mice from established CALC-MEN2B-RET transgenic lines nodular CCH was observed from 8 months on whereas MTC was detected in 13% of mice from one CALC-MEN2B-RET line, from the age of 11 months on. These results show for the first time that the MEN2B mutation in the RET oncogene predisposes mice for MTC. PMID: 10871866 [PubMed - indexed for MEDLINE] DR247: World J Surg. 2000 Aug;24(8):952-6. Medullary carcinoma of the thyroid gland. Wells SA Jr, Franz C. Department of Surgery, Washington University School of Medicine, 660 S. Euclid Avenue, Campus Box 8109, St. Louis, Missouri 63110, USA. Medullary thyroid carcinoma (MTC) is an uncommon thyroid tumor that has attracted a great deal of interest because of its frequent presentation as a familial tumor and its primary involvement in the type II multiple endocrine neoplasia (MEN) syndromes MEN-IIA and MEN-IIB and familial medullary thyroid carcinoma (FMTC). The MTC tumor cells secrete the polypeptide hormone calcitonin, which serves as an excellent tumor marker, useful for defining the presence of disease, preoperatively or following thyroidectomy. The discovery that mutations in the RET proto-oncogene are associated with MEN-II syndromes was highly significant in that it demonstrated a clear correlation between genotype and phenotype; and most importantly it provided a mechanism whereby family members at risk could be identified by direct DNA analysis. Virtually all patients with MEN-IIA, MEN-IIB, and FMTC develop MTC; therefore there is a clear rationale for performing thyroidectomy as soon as a RET mutation has been identified. Because MTC appears to be much more aggressive in patients with MEN-IIB, thyroidectomy is performed during the first year of life in this setting, whereas in patients with MEN-IIA, where the tumor appears to be more indolent, the procedure can be safety delayed until age 5 years. Reoperative neck exploration in patients with evidence of persistent or recurrent MTC has been effective in a significant number of patients, although the success of the operation requires careful patient selection and preoperative assessment. MTC, as expressed in the MEN-II syndromes, is an excellent model to evaluate the usefulness of interventional therapy in patients demonstrated to have a genetic predisposition for cancer. Publication Types: Review Review, Tutorial PMID: 10865039 [PubMed - indexed for MEDLINE] DR248: World J Surg. 2000 Aug;24(8):923-33. Molecular genetics of thyroid tumors and surgical decision-making. Learoyd DL, Messina M, Zedenius J, Robinson BG. Cancer Genetics Unit, Kolling Institute of Medical Research, Royal North Shore Hospital, St. Leonards, New South Wales 2065, Australia. The study of thyroid tumor genetics has great relevance to surgeons and facilitates understanding tumor pathogenesis, prediction of tumor behavior, and management decisions. The genes implicated can be broadly categorized as oncogenes or tumor-suppressor genes. The RET oncogene has well established roles in the development of both papillary (PTC) and medullary (MTC) thyroid carcinoma. Genetic screening for germline RET mutations in members of multiple endocrine neoplasia type II (MEN-II) families is now widely performed, and prophylactic thyroidectomy in gene carriers is advisable at an early age. Patients with apparently sporadic MTC can also be screened to rule out familial disease. The demonstration of a RET rearrangement in a patient's PTC may have prognostic significance, but as yet there are no management implications. The thyrotropin receptor (TSH-R) and Gsalpha become oncogenic through point mutation and are associated with the development of toxic thyroid adenomas. The ras oncogene is implicated in the early stages of development of several thyroid tumor types. Tumor-suppressor genes also have a role in thyroid tumor formation. The p53 gene appears to be involved in the process of transformation to the anaplastic phenotype and the PTEN gene in the development of follicular adenomas but not carcinomas. There is still limited evidence for the so called adenoma-carcinoma sequence of the thyroid follicular cell. Loss of heterozygosity studies have enabled identification of tumor-suppressor genes, and their findings suggests differences in the pathogenesis of PTCs compared with follicular cancers. Surgical decision-making will benefit from these basic molecular advances, which rapidly translates into improved patient management. Publication Types: Review PMID: 10865036 [PubMed - indexed for MEDLINE] NR249: Mol Cell Neurosci. 2000 Jun;15(6):522-33. Expression and alternative splicing of mouse Gfra4 suggest roles in endocrine cell development. Lindahl M, Timmusk T, Rossi J, Saarma M, Airaksinen MS. Program in Molecular Neurobiology, Institute of Biotechnology, Helsinki, FIN-00014, Finland. Members of the GDNF protein family signal through receptors consisting of a GPI-linked GFRalpha subunit and the transmembrane tyrosine kinase Ret. Here we characterize the mouse Gfra4 and show that it undergoes developmentally regulated alternative splicing in several tissues. The mammalian GFRalpha4 receptor lacks the first Cys-rich domain characteristic of other GFRalpha receptors. Gfra4 is expressed in many tissues, including nervous system, in which intron retention leads to a putative intracellular or secreted GFRalpha4 protein. Efficient splicing occurs only in thyroid, parathyroid, and pituitary and less in adrenal glands. A splice form that leads to a GPI-linked GFRalpha4 receptor is expressed in juvenile thyroid and parathyroid glands. In newborn and mature thyroid as well as in parathyroid and pituitary glands major transcripts encode for a putative transmembrane isoform of GFRalpha4. Significant loss of thyroid C cells in Ret-deficient mice suggests that C cells and cells in adrenal medulla, which also express Ret, may require signaling via the GFRalpha4-Ret receptor. Finally, in human, GFRalpha4 expression may restrict the inherited cancer syndrome multiple endocrine neoplasia type 2, associated with mutations in RET, to these cells. Copyright 2000 Academic Press. PMID: 10860579 [PubMed - indexed for MEDLINE] DR250: Cancer Res. 2000 Jun 1;60(11):2786-9. Translocation t(10;14)(q11.2:q22.1) fusing the kinetin to the RET gene creates a novel rearranged form (PTC8) of the RET proto-oncogene in radiation-induced childhood papillary thyroid carcinoma. Salassidis K, Bruch J, Zitzelsberger H, Lengfelder E, Kellerer AM, Bauchinger M. Institute of Radiation Biology, Ludwig Maximilians University, Munchen, Germany. Evaluation of 20 cases of radiation-induced childhood papillary thyroid carcinoma using fluorescence in situ hybridization demonstrated the presence of clonal translocations affecting the RET locus. Semiquantitative reverse transcription-PCR indicated overexpression of the RET tyrosine kinase (TK) domain in four cases. In two cases, the RET rearrangements PTC6 and PTC7 were identified and assigned to balanced translocations t(7;10)(q32;q11.2) and t(1;10)(p13;q11.2), respectively. In one case with a balanced translocation t(10;14)(q11.2;q22.1), 5' rapid amplification of cDNA ends revealed a novel type of RET oncogenic activation (PTC8), arising from a fusion of the 5' part of the kinectin (KTN1) gene to the TK domain of the RET gene. The presence of coiled-coil domains in the resulting ktn1/ret fusion protein suggests ligand-independent dimerization and thus constitutive activation of the ret TK domain. PMID: 10850414 [PubMed - indexed for MEDLINE] DR251: Eur J Clin Invest. 2000 Jun;30(6):493-500. Sporadic endocrine tumours and their relationship to the hereditary endocrine neoplasia syndromes. Koper JW, Lamberts SW. Department of Internal Medicine, Erasmus University Rotterdam, School of Medicine, The Netherlands. koper@inw3.fgg.eur.nl In the last years of the previous century the genes involved in the aetiology of five endocrine tumour syndromes have been identified. The tumour-suppressor gene that is responsible for Von Hippel-Lindau Disease was cloned in 1993; multiple endocrine neoplasia (MEN) types 2A and 2B and familial medullary thyroid carcinoma were found to be caused by activating mutations in the ret proto-oncogene in 1993 and 1994, and most recently the menin-gene, another tumour-suppressor gene, was shown to be associated with MEN-1. As usual, the answer to one question leads to innumerable new questions. And so, now we want to know the extent to which germ-line mutations (de novo, or otherwise previously undetected) in these genes play a role in the occurrence of the various endocrine tumours that are associated with these syndromes in apparently sporadic cases. We also want to know if the nature of the (germ-line) mutation conveys any information about the characteristics (phenotype) of the disease. We want to know the role of somatic mutations in these genes in truly sporadic tumours. And finally we want to know the exact function of the proteins that are encoded by these genes. The paper by Roijers et al. [1] elsewhere in this issue is an example of a small but well-directed step on the way to address some of these questions with respect to the menin-gene. It addresses the problem of patient selection when looking for germ-line mutations in apparently sporadic MEN-1 patients. In this review we want to give a brief summary of the present status with regard to some of the questions mentioned above, in relation to the endocrine tumour syndromes caused by the vhl, ret and menin genes. Publication Types: Review Review, Tutorial PMID: 10849017 [PubMed - indexed for MEDLINE] DR252: Am J Surg Pathol. 2000 Jun;24(6):853-8. Inherited medullary microcarcinoma of the thyroid: a study of 11 cases. Krueger JE, Maitra A, Albores-Saavedra J. Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX 75235-9073, USA. The authors report 11 patients with genetically determined medullary microcarcinomas. Nine patients were either children or adolescents and two patients were young adults. The youngest patient was 7 years old and the oldest was 34 years of age (mean age, 15.4 yrs). The preoperative diagnosis was based on family history and elevated serum calcitonin levels. In addition, six patients had RET protooncogene mutations in exons 10, 11, and 16. Two patients who had the RET protooncogene mutations did not have serum calcitonin measurements. Nine patients had bilateral medullary microcarcinomas (<1.0 cm), whereas the two patients with unilateral tumors demonstrated multifocal disease. The principle microscopic differences between these genetically determined medullary microcarcinomas and larger sporadic (>1 cm) medullary carcinomas were the low incidence of stromal desmoplasia and amyloid deposition, the high incidence of C-cell hyperplasia, and the low incidence of lymph node metastases. Only one patient, a 34-year-old man, presented with lymph node metastases. All patients remain disease free 11 to 70 months after diagnosis. This small series of thyroid microcarcinomas illustrates the impact molecular diagnostics is having on the management and prognosis of genetically determined medullary carcinoma. PMID: 10843288 [PubMed - indexed for MEDLINE] NR253: Semin Diagn Pathol. 2000 May;17(2):109-19. Thyroid carcinomas with mixed follicular and C-cell differentiation patterns. Papotti M, Volante M, Komminoth P, Sobrinho-Simoes M, Bussolati G. Department of Biomedical Sciences and Human Oncology, University of Turin, Torino, Italy. Divergent endocrine-neuroendocrine differentiation in thyroid carcinoma occurs in mixed medullary-follicular carcinomas (MMFC). Less than 40 cases of MMFC have been reported having highly heterogeneous patterns of growth. Classical medullary carcinoma areas may be intermingled with follicles or papillae or even oxyphilic and solid areas. Calcitonin and thyroglobulin are expressed in different cell populations. Presence of the latter suggests a potential usefulness of radioiodine treatment. The clinical behavior of MMFC does not differ from that of ordinary medullary carcinoma. The histogenesis of MMFC is controversial. The genetic analysis of the 2 neoplastic components showed that they are not derived from a common precursor, but rather display remarkable differences in the genetic profile (RET mutations and allelic losses). In addition, in some cases the follicular component was found to be oligo/polyclonal and therefore possibly hyperplastic rather than neoplastic. The follicular cells may have grown into the medullary carcinoma, after acquiring some molecular defect, being "hostage" of the true neoplastic (medullary) component. Publication Types: Review Review of Reported Cases PMID: 10839611 [PubMed - indexed for MEDLINE] NR254: In Vivo. 2000 Mar-Apr;14(2):367-76. Papillary microcarcinoma of the thyroid: a clinico-pathologic and prognostic review. Nasir A, Chaudhry AZ, Gillespie J, Kaiser HE. Department of Pathology, George Washington University, School of Medicine & Health Sciences, Washington DC 20037, USA. Papillary microcarcinoma (PMC) of the thyroid is the most common form of thyroid cancer, which usually remains clinically silent until its incidental histologic diagnosis in autopsy or surgical material. Autopsy incidence varies from 3%-36%. PMC may, however, present with clinical symptoms, the commonest of which is cervical lymphadenopathy with or without palpable thyroid nodules. Other reported presentations include cystic neck mass, pulmonary mass (es), metastases in the skull or vertebral column. The upper limit of size to define PMC is 10 mm in most studies but many studies include lesions up to 15 mm in diameter. Histologic variants include encapsulated and partially encapsulated papillary carcinoma, circumscribed microcarcinoma and occult sclerosing carcinoma. Younger age and size less than 10 mm (< 15 mm in other studies) are considered to be favorable prognostic factors. Size alone, however, cannot be regarded as a determinant of prognosis. Older age, larger tumor size, distant metastases, capsular invasion and multifocality indicate unfavorable prognosis. Loss of heterozygosity (LOH) is an infrequent finding, since small deletions may be missed by southern blot analysis. Activation of oncogenes ret and trk have been reported in papillary carcinoma. Some authors advocate conservative while others favor aggressive therapy including total thyroidectomy with or without Iodine 131ablation. Additional investigative techniques are needed to identify the subset of PMC cases with a potential for aggressive clinical course, thereby targeting more aggressive therapy to an appropriate subset of tumors. Publication Types: Review PMID: 10836212 [PubMed - indexed for MEDLINE] DR255: Clin Chem Lab Med. 2000 Feb;38(2):113-6. Oncogenes and thyroid cancer. Vecchio G, Santoro M. Centro di Endocrinologia ed Oncologia Sperimentale del CNR, Dipartimento di Biologia e Patologia Cellulare e Molecolare, Universita di Napoli, Federico II Naples, Italy. Human thyroid tumors can be derived either from epithelial follicular cells or from parafollicular C-cells. Follicular cell-derived tumors represent a wide spectrum of lesions, ranging from benign adenomas through differentiated (follicular and papillary) and undifferentiated (anaplastic) carcinomas, thus providing a good model for finding a correlation between specific genetic lesions and histologic phenotype. Follicular adenomas and carcinomas show frequently the presence of mutations in one of the three ras genes. Papillary carcinomas show frequently a specific gene rearrangement which gives rise to the formation of several types of so-called RET/PTC chimeric genes. This lesions occur in almost 50% of papillary cancers and consist in the juxtaposition of the 3' or tyrosine kinase domain of the RET gene (which codes for a receptor protein not normally expressed in follicular thyroid cells) with the 5' domain of ubiquitously expressed genes, which provide the promoter and dimerization functions, necessary for the constitutive activation of RET/PTC proteins. Anaplastic carcinomas are frequently associated with mutations of the p53 tumor suppressor. Finally, point mutations of the RET gene are found in familial endocrine syndromes (FMTC; MEN2A and MEN2B), a common feature of which is the medullary thyroid carcinoma, a malignant tumor derived from parafollicular C-cells. Publication Types: Review Review, Tutorial PMID: 10834397 [PubMed - indexed for MEDLINE] DR256: Exp Clin Endocrinol Diabetes. 2000;108(2):128-32. Comment in: Exp Clin Endocrinol Diabetes. 2000;108(8):493. A RET double mutation in the germline of a kindred with FMTC. Bartsch DK, Hasse C, Schug C, Barth P, Rothmund M, Hoppner W. Department of Surgery, Philipps-University of Marburg, Germany. bartsch@mailer.uni-marburg.de Activating germline mutations of the RET proto-oncogene are found in more than 90% of families with multiple endocrine neoplasia type 2a (MEN 2a) and familial medullary thyroid carcinoma (FMTC). The majority of patients with these hereditary tumors carry germline mutations that result in the substitution of one of five cysteine residues in exon 10 and 11. Different mutations in exons 13, 14 and 15 affecting non-cysteine residues have also been described but are considered to be rare. We now for the first time report a double mutation of the RET proto-oncogene occurring in the germline of a kindred with FMTC. Both mutations occur within the tyrosine kinase domain in exon 14 and lead to the substitution of valine 804 by methionine and arginine 844 by leucine. Since the double mutated allele cosegregated with the disease and was not identified in 200 unrelated normal probands, we conclude that they represent mutations that predispose the individual to the development of FMTC with a mild phenotype. Publication Types: Case Reports PMID: 10826520 [PubMed - indexed for MEDLINE] DR257: Clin Ter. 2000 Jan-Feb;151(1):29-35. [Medullary carcinoma of the thyroid: diagnosis and therapy] [Article in Italian] Giuffrida D, Ferrau F, Bordonaro R, Mattina M, Priolo D, Aiello RA, Cordio S, Motta S, Failla G. Divisione di Oncologia Medica, Ospedale San Luigi, Azienda Ospedaliera Garibaldi, Catania, Italia. Medullary thyroid carcinoma (MTC) originates in the thyroid C cells, or parafollicular cells, secreting calcitonin. It may be either sporadic or familial. Familial form can be isolated or expression of a multiple endocrine neoplasia type II. Mutations of the RET proto-oncogene have been identified in the germline DNA of patients with familial MTC syndromes. Genetic testing can identify patients affected by multiple endocrine neoplasia and familial MTC, allowing early diagnosis and possible cure. The initial treatment is surgical and the adequate surgery consists of total thyroidectomy. The treatment of occult or minimal disease can be curative. Plasma calcitonin measurements are excellent markers for post-operative follow-up. Imaging study can help to discover recurrent or metastatic disease. Adjunctive therapy includes radiotherapy and chemotherapy. Radiotherapy is reserved for bone metastases or for non resectable neck recurrences. Chemotherapy is reserved for patients with progressive MTC. Many chemotherapeutic regimens have been tried, results are controversial. Publication Types: Review Review, Tutorial PMID: 10822879 [PubMed - indexed for MEDLINE] DR258: Eur J Endocrinol. 2000 Jun;142(6):643-9. Expression of RET and its ligand complexes, GDNF/GFRalpha-1 and NTN/GFRalpha-2, in medullary thyroid carcinomas. Frisk T, Farnebo F, Zedenius J, Grimelius L, Hoog A, Wallin G, Larsson C. Department of Molecular Medicine, Endocrine Tumor Unit, Karolinska Hospital, Stockholm, Sweden. tony.frisk@cmm.ki.se OBJECTIVE: Mutations in the RET proto-oncogene are found in about one third of sporadic medullary thyroid carcinomas (MTCs), mostly affecting codon 918. Glial cell line derived neurotropic factor (GDNF) and its membrane-bound GDNF family receptor alpha (GFRalpha-1), as well as neurturin (NTN) and its membrane-bound receptor GFRalpha-2 form a complex with the RET product, a receptor tyrosine kinase, resulting in downstream signaling to the nucleus. DESIGN: To elucidate the role of these RET ligands in MTC tumorigenesis, their expression was determined in 15 MTC samples, one papillary thyroid carcinoma (PTC) and three normal thyroid tissue specimens. METHODS: The mRNA expression of RET, GDNF, GFRalpha-1, NTN and GFRalpha-2 was investigated by mRNA in situ hybridization, and confirmed by reverse transcription-PCR analysis. RESULTS: None of the five genes was expressed in the normal thyroids or in the PTC. All MTCs showed expression of RET, 13 expressed GDNF, 12 expressed GFRalpha-1 and 9 expressed NTN and GFRalpha-2. In 7 of the tumors RET, GDNF and GFRalpha-1 were expressed at high levels, and in five of these seven tumors NTN and GFRalpha-2 genes were also expressed at high levels. The high level of expression was preferentially seen in tumor cells adjacent to stroma and connective tissue. All MTCs without expression of the RET ligands harbored the RET codon 918 mutation. CONCLUSIONS: The results suggest that this signaling pathway is important for MTC development, and that it may be activated by expression of the RET ligand complexes by the tumor cells themselves. PMID: 10822229 [PubMed - indexed for MEDLINE] NR259: Eur J Endocrinol. 2000 Jun;142(6):573-5. Somatic trinucleotide change encompassing codons 882 and 883 of the RET proto-oncogene in a patient with sporadic medullary thyroid carcinoma. Bugalho MJ, Coelho I, Sobrinho LG. Department of Endocrinology/Laboratory of Molecular Biology, Portuguese Cancer Institute, 1093-Lisbon Codex, Portugal. bugalho@mail.telepac.pt OBJECTIVE: Restriction analysis is a straightforward procedure for mutational analysis. It is commonly used for screening RET mutations. Incomplete digestion is a well-known cause of false results. Herein, we report another limitation of the method. DESIGN AND METHODS: Screening for somatic mutations in RET exons 16, 13 and 15 was performed in a patient with a sporadic medullary thyroid carcinoma. Genetic study was carried out by both restriction analysis and direct sequencing. RESULTS: A somatic trinucleotide change encompassing codons 882 and 883 of the RET proto-oncogene (GTA GCT to GTT TTT) was documented. Particular to this case is the silent mutation (GTA-->GTT) at codon 882. Independently, both the novel silent mutation and the missense mutation at codon 883 may disrupt the same AluI restriction site. Based on the restriction pattern we were able to say that both mutations occurred in the same allele. CONCLUSIONS: Restriction analysis is an easy approach for screening RET mutations; however, it is not enough to assign a final diagnosis. Publication Types: Case Reports PMID: 10822219 [PubMed - indexed for MEDLINE] DR260: Pharm Acta Helv. 2000 Mar;74(2-3):261-4. The RET receptor tyrosine kinase: activation, signalling and significance in neural development and disease. Mason I. Department of Developmental Neurobiology, King's College London, UK. ivor.mason@kcl.ac.uk The RET receptor tyrosine kinase was first identified in a screen for human oncogenes and has subsequently been linked to several human syndromes: Hirschprung's disease, multiple endocrine neoplasia types 2A and 2B and familial thyroid carcinoma. Interestingly, all of the tissues affected by mutations in RET are derived from the neural crest during development. RET transduces a signal following activation by ligands of the glial cell line-derived neurotrophic factor (GDNF) family of neurotrophins which currently comprises GDNF, neuturin (NTN), artemin (ART) and persephin (PSP). To activate RET they form a tripartite complex with RET and a member of a family of four extracellular, GPI-linked alpha receptors (GFR alpha 1-4). Specificity is achieved by each GFR alpha binding only one member of the GDNF family with high affinity. Current evidence indicates that signal transduction by RET activates several second messenger systems including the PLC gamma, Ras, JNK and inositol phosphate pathways. Targeted mutagenesis in transgenic mice has shown that Ret, GFR alpha 1 and GDNF are required for multiple developmental events including development of the enteric nervous system (ENS) affected in Hirschsprung's disease. We describe experiments in chick neural crest cells which provide evidence for the normal function of RET and the basis of the defect in Hirschsprung's disease. Publication Types: Review Review, Tutorial PMID: 10812967 [PubMed - indexed for MEDLINE] DR261: Semin Surg Oncol. 2000 Jun;18(4):324-32. Multiple endocrine neoplasias. Phay JE, Moley JF, Lairmore TC. Department of Surgery, Washington University School of Medicine, St. Louis, Missouri, USA. Multiple endocrine neoplasia type 1 (MEN 1), and the multiple endocrine neoplasia type 2 syndromes (MEN 2A, MEN 2B, and familial non-MEN medullary thyroid carcinoma [FMTC]) encompass a wide range of endocrine problems, but arise from only two genes: the MEN 1 tumor suppressor gene and the RET proto-oncogene. MEN 1 is characterized by parathyroid hyperplasia, pancreaticoduodenal neuroendocrine tumors (PNTs), and pituitary adenomas. Surgery is the principal treatment modality for hyperparathyroidism and PNTs, but questions still remain concerning the timing and extent of surgery for PNTs. The MEN 2 syndromes are characterized by complete penetrance of medullary thyroid cancer. The MEN 2 syndromes differ in their variable expression of hyperparathyroidism, pheochromocytomas, and other clinical features. Genetic testing for mutations in the RET gene has revolutionized treatment by enabling thyroidectomies before significant disease occurs. Copyright 2000 Wiley-Liss, Inc. Publication Types: Review Review, Tutorial PMID: 10805954 [PubMed - indexed for MEDLINE] DR262: Semin Nucl Med. 2000 Apr;30(2):133-40. The Chernobyl accident and its consequences: update at the millennium. Tuttle RM, Becker DV. Endocrinology Service, Memorial Sloan-Kettering Cancer Center, New York Presbyterian Hospital, Weill Medical College of Cornell University, NY 10021, USA. A marked increase in the incidence of papillary thyroid cancer in children has been documented in regions of the former Soviet Union most heavily contaminated by radioactive fallout from the Chernobyl nuclear power plant accident in April 1986. Accumulation of radioactive iodines by normal iodine trapping mechanisms resulted in significant radiation doses to the thyroid gland. Although it has long been known that thyroidal radiation resulted in nuclear and chromosomal abnormalities visible by light microscopy, modern molecular biology techniques are beginning to identify much smaller alterations in chromosomal coding sequences that are associated with malignant transformation. Although stable chromosomal abnormalities can be detected in Chernobyl-associated thyroid cancers, they are much less prevalent than in thyroid cancers developing after external beam irradiation. However, several unique chromosomal breakpoints have been described in radiation-associated thyroid cancers that are not commonly found in spontaneously occurring thyroid cancer. Furthermore, activation of specific subtypes of the ret/PTC tyrosine kinase oncogene appears to be more common in radiation-associated thyroid cancers than in spontaneous thyroid cancers. In summary, thyroid cancers developing in the aftermath of the Chernobyl accident provide a unique opportunity to search for chromosomal abnormalities that may be specific for radiation-induced thyroid cancer. Publication Types: Review PMID: 10787193 [PubMed - indexed for MEDLINE] DR263: Cytogenet Cell Genet. 2000;88(1-2):56-61. RET rearrangements in papillary thyroid carcinomas and adenomas detected by interphase FISH. Cinti R, Yin L, Ilc K, Berger N, Basolo F, Cuccato S, Giannini R, Torre G, Miccoli P, Amati P, Romeo G, Corvi R. Istituto G. Gaslini, Laboratorio di Genetica Molecolare and Dipartimento di Oncologia, Biologia e Genetica, Universita di Genova, Genova, Italy. Activation of the RET protooncogene through somatic rearrangements represents the most common genetic alteration in papillary thyroid carcinoma (PTC). Three main rearranged forms of RET have been described: RET/PTC1 and RET/PTC3, which arise from a paracentric inversion of the long arm of chromosome 10, and RET/PTC2, which originates from a 10;17 translocation. We have developed a dual-color FISH approach to detect RET/PTC rearrangements in interphase nuclei of thyroid lesions. By using a pool of three cosmids encompassing the RET chromosome region and a chromosome 10 centromeric probe, we could discriminate between the presence of an inversion (RET/PTC1 and RET/PTC3) or a translocation (RET/PTC2). We have investigated a series of thyroid tissue samples from Italian and French patients corresponding to a total of 69 PTCs and 22 benign lesions. Among PTCs, 13 (18.8%) showed a RET rearrangement, and 11 (15.9%) of these carried an inversion (RET/PTC1 or RET/PTC3) in more than 10% of the nuclei examined. Activated forms of RET were also observed in three adenomas. RT-PCR analysis on the same samples confirmed the presence and the type of rearrangement predicted using FISH analysis. An interesting difference in the frequency and type of RET rearrangements was detected between the Italian and the French patients. Furthermore, we identified a putative novel type of rearrangement in at least one PTC sample. Several PTCs carried a significant number of cells characterized by a trisomy or a tetrasomy of chromosome 10. Overall, the FISH approach in interphase nuclei represents a powerful tool for detecting, at the single cell level, RET/PTC rearrangements and other anomalies involving the RET chromosome region. Copyright 2000 S. Karger AG, Basel PMID: 10773666 [PubMed - indexed for MEDLINE] DR264: N Engl J Med. 2000 Apr 20;342(16):1218-9. Unilateral renal agenesis in a family with medullary thyroid carcinoma. Lore F, Di Cairano G, Talidis F. Publication Types: Letter PMID: 10777380 [PubMed - indexed for MEDLINE] DR265: Exp Clin Endocrinol Diabetes. 2000;108(1):49-53. Absence of H- and K-ras oncogene mutations in sporadic medullary thyroid carcinoma. Bockhorn M, Frilling A, Kalinin V, Schroder S, Broelsch CE. Department of General and Transplantation Surgery, University Clinic Essen, Germany. Medullary thyroid carcinoma (MTC) occurs sporadically (sMTC) or as part of the inherited cancer syndrome, multiple endocrine neoplasia type 2 (MEN 2). While the occurence of the MEN 2 syndrome is associated with mutations in the RET protooncogene, the reason for carcinogenesis in sMTC still remains unclear. Ras is a frequently mutated oncogene in a broad spectrum of human tumors and has been found in about 50% of follicular, papillary or anaplastic thyroid carcinomas. The purpose of this study was to determine, whether mutations in the ras oncogene could play a possible role in the carcinogenesis of sMTC. In this study we analyzed 15 sMTC for mutations in the hotspots codon 12, 13 and 61 of the H- and K-ras oncogene. We used the direct sequencing technique. In none of the examined tumors we were able to detect a mutation in the codon 12, 13 and 61 of the H-ras and K-ras oncogene. Based upon these results, we conclude that H- and K-ras do not play an important role in the carcinogenesis of sMTC. PMID: 10768832 [PubMed - indexed for MEDLINE] DR266: J Biol Chem. 2000 Jun 23;275(25):19297-305. Signaling through Ras is essential for ret oncogene-induced cell differentiation in PC12 cells. Califano D, Rizzo C, D'Alessio A, Colucci-D'Amato GL, Cali G, Bartoli PC, Santelli G, Vecchio G, de Franciscis V. Centro di Endocrinologia ed Oncologia Sperimentale del Consiglio Nazionale delle Ricerche, c/o Dipartimento di Biologia e Patologia Cellulare e Molecolare, Universita di Napoli "Federico II," via S. Pansini 5, 80131 Naples, Italy. Specific germline mutations of the receptor tyrosine kinase, Ret, predispose to multiple endocrine neoplasia types 2A and 2B and familial medullary thyroid carcinoma. The mechanisms by which different Ret isoforms (Ret-2A and Ret-2B) cause distinct neoplastic diseases remain largely unknown. On the other hand, forced expression of these mutated versions of Ret induces the rat pheochromocytoma cell line, PC12, to differentiate. Here we used an inducible vector encoding a dominant-negative Ras (Ras p21(N17)) to investigate the contributions of the Ras pathway to the phenotype induced in PC12 cells by the expression of either Ret-2A or Ret-2B mutants. We show that the Ret-induced molecular and morphological changes are both mediated by Ras-dependent pathways. However, even though inhibition of Ras activity was sufficient to revert Ret-induced differentiation, the kinetics of morphological reversion of the Ret-2B- was more rapid than the Ret-2A-transfected cells. Further, we show that in Ret-transfected cells the suc1-associated neurotrophic factor-induced tyrosine phosphorylation target, SNT, is chronically phosphorylated in tyrosine residues, and associates with the Sos substrate. These results indicate the activation of the Ras cascade as an essential pathway triggered by the chronic active Ret mutants in PC12 cells. Moreover, our data indicate SNT as a substrate for both Ret mutants, which might mediate the activation of this cascade. PMID: 10748077 [PubMed - indexed for MEDLINE] NR267: Rev Port Cardiol. 2000 Jan;19(1):11-31. Comment in: Rev Port Cardiol. 2000 Jan;19(1):33-8. Multiple endocrine neoplasia type 2A. Study of a family. [Article in English, Portuguese] Correia MJ, Lopes LO, Bugalho MJ, Cristina L, Santos AI, Bordalo AD, Pinho B, da Silva HL, Goncalves MD, Ribeiro C, Tuna JL. UTIC-Arsenio Cordeiro, Hospital de Santa Maria, Lisboa. INTRODUCTION: Pheochromocytomas (Pheo) can occur sporadically, isolated or in association with other neuroendocrine lesions. In multiple endocrine neoplasia type 2A (MEN-2A), Pheo is associated to medullary thyroid carcinoma (MTC) or its precursor, C-cell hyperplasia (CCH) and parathyroid hyperplasia. Genetic screening provides early diagnosis and preventive treatment. In order to validate DNA analysis as a reliable method of early identification of gene carriers, we compared the results of genetic screening with clinical, biochemical, imaging and pathological findings in the members of an affected family. POPULATION AND METHODS: The diagnosis of a bilateral necrotic Pheo in a female patient led to the study of a family with four generations, aged 3 to 78 years (mean = 30.3 yrs). The study included a clinical examination; basal and pentagastrin stimulated calcitonin values; urinary catecholamines and their metabolites; serum calcium and a genetic study (direct sequence of PCR products from genomic DNA isolated from leucocytes using specific primers in exon 11 of the RET protooncogene of chromosome 10). The radiologic study, gammagraphic study (131I-MIBG) and magnetic resonance study were performed in members with clinical suspicion of Pheo. RESULTS: Seven out of nine patients had a mutation on codon 634 of exon 11 of RET (TGC-CGC), leading to cysteine arginine substitution in the codified protein; all gene carriers had biochemical markers of MTC/CCH and four of Pheo. The Pheo patients underwent adrenalectomy (bilateral in three) and all the gene carriers underwent prophylactic thyroidectomy. The pathologic findings were: MTC in four (metastasized in one); CCH in three and parathyroid hyperplasia in one. CONCLUSIONS: Phenotypic penetration of RET mutation was 100% for MTC/CCH, but only 57% of the gene carriers had Pheo. Genetic screening allowed early prophylactic treatment in four out of seven patients; pathologic findings revealed several evolutionary stages of the disease. Patients not yet showing Pheo are under close clinical and laboratory surveillance. Publication Types: Case Reports Review Review of Reported Cases PMID: 10731788 [PubMed - indexed for MEDLINE] DR268: J Clin Endocrinol Metab. 2000 Mar;85(3):1170-5. The ret/PTC mutations are common in sporadic papillary thyroid carcinoma of children and young adults. Fenton CL, Lukes Y, Nicholson D, Dinauer CA, Francis GL, Tuttle RM. Department of Pediatrics, Walter Reed Army Medical Center, Washington, DC 20307, USA. The ret/PTC rearrangements (PTC-1, PTC-2, and PTC-3) are characteristic of papillary thyroid cancer (PTC). In adults, PTC-1 is common and may be associated with an aggressive clinical course. The incidence and significance of ret/PTC mutations are less well understood in children. We examined spontaneous PTC from 33 patients (23 females and 10 males) with a median age of 18 yr (range, 6-21 yr) and a median follow-up of 3.5 yr (range, 0-13.4 yr). The ret/PTC mutations were identified in 15 tumors (45%), including 8 PTC-1 (8 of 15, 53%), 2 PTC-2 (2 of 15, 13%), 2 PTC-3 (2 of 15, 13%), and 3 (3 of 15, 20%) combined PTC mutations (PTC-1 and PTC-2). This distribution is significantly different (P = 0.001, by chi2 analysis) from that reported for children with radiation-induced PTC. There was no correlation between the presence or type of ret/PTC mutation and patient age, tumor size, focality, extent of disease at diagnosis, or recurrence. We conclude that ret/PTC mutations are 1) common in sporadic childhood PTC, 2) predominantly PTC-1, 3) frequently multiple, and 4) of different distribution than that reported for children with radiation-induced PTC. Publication Types: Clinical Trial PMID: 10720057 [PubMed - indexed for MEDLINE] NR269: J Hum Genet. 2000;45(1):6-11. Genomic organization and chromosomal mapping of ELKS, a gene rearranged in a papillary thyroid carcinoma. Yokota T, Nakata T, Minami S, Inazawa J, Emi M. Department of Molecular Biology, Nippon Medical School, Kawasaki, Japan. We recently isolated a novel cDNA, designated ELKS, that was fused to RET cDNA in a papillary thyroid carcinoma. Its encoded polypeptide sequence was rich in glutamic acid (E), leucine (L), lysine (K), and serine (S), and was characterized by the presence of nine alpha-helical coiled-coil domains consisting of periodic heptad repeats. We have now cloned the entire structure of the human ELKS gene from within a 700-kb genomic region represented by overlapping bacteriophage P1-derived artificial chromosome (PAC) and bacterial artificial chromosome (BAC) clones, and localized it to chromosomal band 12p13.3 by fluorescence in situ hybridization. The gene is approximately 500 kb long, with 19 exons and 18 introns; the transcription initiation site within exon 1 is separate from the initiation codon (in exon 2). Analysis of the exon/intron structure revealed that introns interrupt the coding sequence in such a way that many functional segments of the protein are encoded by distinct exons. Exon 1 encodes the 5' non-coding region; exons 2, 3, 6, 7, 8, 9, 11, 14, and 15 encode the nine coiled-coil domains. Exons 17-19 constitute the 3' non-coding region. Analysis of the region immediately upstream of exon 1 showed that it was extremely rich in G/C nucleotides and contained multiple Sp-1 and AP2 binding sequences. The ELKS-RET gene fusion rearrangement we had observed in a papillary thyroid carcinoma occurred between intron 10 of the ELKS gene and intron 11 of RET. PMID: 10697956 [PubMed - indexed for MEDLINE] DR270: Scand J Clin Lab Invest. 1999 Dec;59(8):643-7. Rapid MEN 2A gene carrier identification using primer-specific PCR amplification. Kroustrup JP, Laurberg P, Madsen PH. Department of Endocrinology and Medicine, Aalborg Hospital, Denmark. DNA testing is of great importance in families with multiple endocrine neoplasia (MEN) type 2A to identify non-mutant carrying family members and asymptomatic mutation carriers, and also to confirm the diagnosis in patients who already show clinical or biochemical signs of disease. Several point mutations of the RET proto-oncogene on exons 10 and 11 are associated with the disease, which is characterized by medullary thyroid carcinoma, pheochromocytoma and hyperparathyroidism. The aim of the present study was to develop and evaluate a simple method, which indicates the mutational status of members of families where the site of the point mutation is known. The method is illustrated by the detection of mutation TGC-->TAC of codon 611, which is one of the well-known mutations associated with MEN 2A. The method involves the PCR technique with allele-specific primers and detection of the amplified sequences with biotinylated probes. There was a clear-cut difference between the readings from affected and unaffected subjects. The subjects had been evaluated independently and all subjects harboring the mutation also had clinical disease. The method provides a simple and reliable diagnostic tool for DNA screening of members of families with a known mutation of the RET-gene. Publication Types: Clinical Trial PMID: 10691056 [PubMed - indexed for MEDLINE] PR271: Cancer Genet Cytogenet. 1999 Jul 15;112(2):178-80. Translocations (X;10)(p22;q24) and (1;10)(q21;q11) in a follicular adenoma of the thyroid without apparent involvement of the RET protooncogene. van Zelderen-Bhola S, Vink R, Smit J, Wessels H, Morreau H. Department of Clinical Cytogenetics, Leiden University Medical Centre, The Netherlands. We report here the cytogenetic analysis of a follicular adenoma of the thyroid which revealed an abnormal clone with a t(X;10)(p22;q24) and a t(1;10)(q21;q11) together with normal cells. Fluorescence in situ hybridization (FISH) with YACs 273E3 and 344H4, which are located on 10q11.2 and are specific for the RET protooncogene, showed no abnormalities. It would therefore appear that this gene is not involved in the particular tumor, as has been reported in a number of papillary thyroid carcinomas. Several chromosomal aberrations have been suggested as been specific for follicular thyroid adenoma. However, until now, only a few such cases have been reported which involve structural abnormalities of chromosomes 10q11.2 and 10q24. We believe this to be the first report of a follicular thyroid adenoma with a t(X;10)and a t(1;10). Publication Types: Case Reports PMID: 10686949 [PubMed - indexed for MEDLINE] DR272: Biochem Biophys Res Commun. 2000 Feb 24;268(3):804-8. A two-hit model for development of multiple endocrine neoplasia type 2B by RET mutations. Iwashita T, Murakami H, Kurokawa K, Kawai K, Miyauchi A, Futami H, Qiao S, Ichihara M, Takahashi M. Department of Pathology, Nagoya University School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, 466-8550, Japan. Multiple endocrine neoplasia (MEN) type 2B mutations have been reported at methionine 918 or alanine 883 in the tyrosine kinase domain of the RET proto-oncogene. Recently, a new combination of two germline missense mutations at valine 804 and tyrosine 806 was identified in a patient with MEN 2B-like clinical phenotypes including medullary thyroid carcinoma, mucosal neuroma, and marfanoid habitus. In this case, valine 804 and tyrosine 806 were replaced with methionine and cysteine, respectively. In the present study, biological activities of RET with these new mutations were compared with those with known MEN 2A or MEN 2B mutations. The transforming activity of RET with the V804M/Y806C mutation was about 8- to 13-fold higher than that of RET with a single V804M or Y806C mutation. Like RET with the M918T or A883F MEN 2B mutation, the transforming activity of RET with the V804M/Y806C mutation was not affected by substitution of phenylalanine for tyrosine 905 that abolished the activity of RET with the MEN 2A mutation. On the other hand, substitution of phenylalanine for tyrosines 864 and 952 drastically diminished the activity of RET with the V804M/Y806C, M918T or A883F mutation, suggesting that these three mutant proteins have similar biological properties. Copyright 2000 Academic Press. Publication Types: Case Reports PMID: 10679286 [PubMed - indexed for MEDLINE] DR273: EMBO J. 2000 Feb 15;19(4):612-22. C-cell hyperplasia, pheochromocytoma and sympathoadrenal malformation in a mouse model of multiple endocrine neoplasia type 2B. Smith-Hicks CL, Sizer KC, Powers JF, Tischler AS, Costantini F. Department of Genetics and Development, College of Physicians and Surgeons, Columbia University, 701 W. 168th Street, New York, NY 10032, USA. Dominantly inherited multiple endocrine neoplasia type 2B (MEN2B) is characterized by tumors of the thyroid C-cells and adrenal chromaffin cells, together with ganglioneuromas of the gastrointestinal tract and other developmental abnormalities. Most cases are caused by substitution of threonine for Met918 in the RET receptor tyrosine kinase, which is believed to convert the RET gene to an oncogene by altering the enzyme's substrate specificity. We report the production of a mouse model of MEN2B by introduction of the corresponding mutation into the ret gene. Mutant mice displayed C-cell hyperplasia and chromaffin cell hyperplasia progressing to pheochromocytoma. Homozygotes did not develop gastrointestinal ganglioneuromas, but displayed ganglioneuromas of the adrenal medulla, enlargement of the associated sympathetic ganglia and a male reproductive defect. Surprisingly, homozygotes did not display any developmental defects attributable to a loss-of-function mutation. Thus, while our results support the conclusion that the Met918Thr substitution is responsible for MEN2B, they suggest that the substrate specificity of the RET kinase does not interfere with its normal role in the development of the kidneys and enteric nervous system. PMID: 10675330 [PubMed - indexed for MEDLINE] DR274: J Biol Chem. 2000 Feb 4;275(5):3568-76. Transforming ability of MEN2A-RET requires activation of the phosphatidylinositol 3-kinase/AKT signaling pathway. Segouffin-Cariou C, Billaud M. Laboratoire de Genetique, CNRS UMR 5641, Domaine Rockefeller, 8 Avenue Rockefeller, 69373 Lyon, Cedex 08, France. The RET gene codes for a receptor tyrosine kinase that plays a crucial role during the development of both the enteric nervous system and the kidney. Germ line missense mutations at one of six codons specifying extracytoplasmic cysteines are responsible for two related cancer disorders as follows: multiple endocrine neoplasia type2A (MEN2A) and familial medullary thyroid carcinoma (FMTC). MEN2A and FMTC mutations result in a constitutive catalytic activity and as a consequence convert RET into a dominantly acting transforming gene. Although it has been shown that RET-MEN2 mutants activate several transduction pathways, their respective contribution to the neoplastic phenotype remains poorly understood. Over the past few years, it has become increasingly clear that the transforming ability of several viral and cellular oncoproteins depends on their capacity to activate phosphatidylinositol 3-kinase (PI3K). We now report that RET carrying a representative MEN2A mutation at Cys-634 (termed RET-MEN2A) activates PI3K and its downstream effector, the serine/threonine kinase AKT/protein kinase B. Previous studies have demonstrated that mutation of Tyr-1062, which is the intracellular docking site for Shc and Enigma on RET, abolishes the RET-MEN2A transforming activity. We provide evidence that mutation of Tyr-1062 abrogates the binding of the p85 regulatory subunit of PI3K to RET-MEN2A and the subsequent stimulation of the PI3K/AKT pathway. Furthermore, infection of rat fibroblasts with a retrovirus expressing a dominant-interfering form of PI3K suppresses RET-MEN2A-dependent transformation, whereas overexpression of AKT enhances the RET-MEN2A oncogenic potential. In summary, these data are consistent with the notion that RET-mediated cell-transforming effect is critically dependent on the activation of the PI3K/AKT pathway. PMID: 10652352 [PubMed - indexed for MEDLINE] DR275: Br J Cancer. 2000 Jan;82(2):315-22. Gene rearrangement and Chernobyl related thyroid cancers. Santoro M, Thomas GA, Vecchio G, Williams GH, Fusco A, Chiappetta G, Pozcharskaya V, Bogdanova TI, Demidchik EP, Cherstvoy ED, Voscoboinik L, Tronko ND, Carss A, Bunnell H, Tonnachera M, Parma J, Dumont JE, Keller G, Hofler H, Williams ED. Centro di Endocrinologia ed Oncologia Sperimentale del CNR, Dipartimento di Biologia e Patologia Cellulare e Moleculare, Universita di Napoli, Italy. The increase in thyroid carcinoma post-Chernobyl has been largely confined to a specific subtype of papillary carcinoma (solid/follicular). This subtype is observed predominantly in children under 10 in unirradiated populations, but maintains a high frequency in those aged 10-15 from those areas exposed to fallout from the Chernobyl accident. The aim of this study was to link morphology with molecular biology. We examined 106 papillary carcinomas from children under the age of 15 at operation. All were examined for rearrangements of the RET oncogene by reverse transcription polymerase chain reaction (RT-PCR); a subset of these cases were also examined for mutations of the three ras oncogenes, exon 10 of the thyroid stimulating hormone receptor, associated more usually with a follicular rather than papillary morphology, and exons 5, 6, 7 and 8 of the p53 gene, commonly involved in undifferentiated thyroid carcinoma. Rearrangements of the REToncogene were found in 44% of papillary carcinomas in which we studied fresh material; none of the tumours examined showed mutation in any of the other genes. The two rearrangements resulting from inversion of part of chromosome 10 (PTC1 and PTC3) accounted for the majority of RET rearrangements identified, with PTC1 being associated with papillary carcinomas of the classic and diffuse sclerosing variants and PTC3 with the solid/follicular variant. PMID: 10646883 [PubMed - indexed for MEDLINE] NR276: Orv Hetil. 1999 Dec 5;140(49):2739-46. [Molecular genetic study of medullary thyroid cancer] [Article in Hungarian] Klein I, Homolya V, Varadi A, Esik O. MTA Szegedi Biologiai Kozpont Enzimologiai Intezet, Budapest. Around 25% of medullary thyroid carcinoma (MTC) cases are familial and follow an autosomal dominant mode of inheritance. In these cases, MTC is part of an inherited cancer syndrome that has three distinct forms: MEN2A, MEN2B and familial MTC (FMTC). MEN2A is the most frequent syndrome, followed by FMTC and MEN2B. In 95% of MEN2A families and 85% of FMTC families, the germ-line missense mutations underlying the disease affect one of the five cysteine codons of the extracellular domain of the RET proto-oncogene. The mutated codons are 609, 611, 618 and 620 in exon 10, and 634 in exon 11. The most frequent mutations (80% in MEN2A, and 50% in FMTC) occur in codon 634. In our laboratory, the mutations of the codon 634 was detected by two independent methods: DNA sequencing and restriction fragment length polymorphism with polymerase chain reaction (PCR-RFLP). We have so far examined 105 persons at risk and found 19 positive cases. A positive genetic diagnosis allows preventive thyroidectomy, with a resultant cause-specific survival similar to that for the general population. In the event of a negative result, the family members of the affected proband are relieved of the physical and emotional consequences of the disease and the follow-up procedures. We plan to screen all 240 known Hungarian MTC patients and their relatives. PMID: 10628190 [PubMed - indexed for MEDLINE] DR277: Acta Paediatr Suppl. 1999 Dec;88(433):23-7. Thyroid consequences of the Chernobyl nuclear accident. Pacini F, Vorontsova T, Molinaro E, Shavrova E, Agate L, Kuchinskaya E, Elisei R, Demidchik EP, Pinchera A. Department of Endocrinology, University of Pisa, Italy. fpacini@endoc.med.unipi.it It is well recognized that the use of external irradiation of the head and neck to treat patients with various non-thyroid disorders increases their risk of developing papillary thyroid carcinoma years after radiation exposure. An increased risk of thyroid cancer has also been reported in survivors of the atomic bombs in Japan, as well as in Marshall Island residents exposed to radiation during the testing of hydrogen bombs. More recently, exposure to radioactive fallout as a result of the Chernobyl nuclear reactor accident has clearly caused an enormous increase in the incidence of childhood thyroid carcinoma in Belarus, Ukraine, and, to a lesser extent, in the Russian Federation, starting in 1990. When clinical and epidemiological features of thyroid carcinomas diagnosed in Belarus after the Chernobyl accident are compared with those of naturally occurring thyroid carcinomas in patients of the same age group in Italy and France, it becomes apparent that the post-Chernobyl thyroid carcinomas were much less influenced by gender, virtually always papillary (solid and follicular variants), more aggressive at presentation and more frequently associated with thyroid autoimmunity. Gene mutations involving the RET proto-oncogene, and less frequently TRK, have been shown to be causative events specific for papillary cancer. RET activation was found in nearly 70% of the patients who developed papillary thyroid carcinomas following the Chernobyl accident. In addition to thyroid cancer, radiation-induced thyroid diseases include benign thyroid nodules, hypothyroidism and autoimmune thyroiditis, with or without thyroid insufficiency, as observed in populations after environmental exposure to radioisotopes of iodine and in the survivors of atomic bomb explosions. On this basis, the authors evaluated thyroid autoimmune phenomena in normal children exposed to radiation after the Chernobyl accident. The results demonstrated an increased prevalence of circulating thyroid antibodies not associated with significant thyroid dysfunction. This finding is consistent with the short period of follow-up, but it is highly likely that these children will develop clinical thyroid autoimmune diseases in the future. Therefore, screening programmes for this at-risk population should focus, not only on the detection of thyroid nodules and cancer, but also on the development of thyroid autoimmune diseases. PMID: 10626541 [PubMed - indexed for MEDLINE] DR278: Jpn J Cancer Res. 1999 Nov;90(11):1231-7. Somatic mutations in RET exons 12 and 15 in sporadic medullary thyroid carcinomas: different spectrum of mutations in sporadic type from hereditary type. Uchino S, Noguchi S, Yamashita H, Sato M, Adachi M, Yamashita H, Watanabe S, Ohshima A, Mitsuyama S, Iwashita T, Takahashi M. Noguchi Thyroid Clinic and Hospital Foundation, Beppu, Oita. uchino@noguchi-med.or.jp Germline mutations in the RET proto-oncogene are responsible for multiple endocrine neoplasia type 2 (MEN 2A and 2B) and familial medullary thyroid carcinoma (FMTC). Point mutations or in-frame deletions of exons 10, 11, 13, 14 and 16 are associated with sporadic medullary thyroid carcinoma (MTC). To understand further the role of the RET gene in sporadic MTC, we examined mutations in exons 12 and 15 of RET in patients with sporadic MTC. DNAs were extracted from 39 formalin-fixed tumor tissues and corresponding normal thyroid tissues or peripheral blood leukocytes. DNA sequencing was used to identify mutations in exons 12 and 15 of RET. In this study, one novel somatic mutation was found in exon 12 and five novel mutations or deletions were found in exon 15. Of the patients with mutations, one had an in-frame 12-bp deletion (nt. 2625-2636), one had point mutations in both codons 884 and 908, and the remaining three had point mutations in codons 748, 876 and 901, respectively. Together with our previous identification of somatic mutations in exons 10, 11, 13, 14 and 16, somatic alterations were found in 10 out of 39 (25.6%) sporadic MTCs. There was no association of RET gene mutations with tumor recurrence or prognosis. These results suggest that mutations occur frequently in the RET coding region in addition to the previously reported mutation hot spots, and there is a different spectrum of mutations between sporadic and hereditary MTC. PMID: 10622534 [PubMed - indexed for MEDLINE] DR279: Hum Mutat. 2000 Jan;15(1):122. A new germline mutation, R600Q, within the coding region of RET proto-oncogene: a rare polymorphism or a MEN 2 causing mutation? Saez ME, Ruiz A, Cebrian A, Morales F, Robledo M, Antinolo G, Borrego S. Unidad de Genetica Medica y Diagnostico Prenatal, Hospitales Universitarios Virgen del Rocio, Sevilla, Spain. PMID: 10612852 [PubMed - indexed for MEDLINE] NR280: Teratog Carcinog Mutagen. 2000;20(1):1-9. Nmethyl-N-nitrosourea (MNU) induces papillary thyroid tumours which lack ras gene mutations in the hermaphroditic fish Rivulus marmoratus. Lee JS, Park EH, Choe J, Chipman JK. Department of Biology, College of Natural Sciences, Hanyang University, Seoul, South Korea. jslee2@plaza1.snu.ac.kr To investigate the patterns of alkylating agent-induced tumour formation, 40 fish (Rivulus marmoratus) were exposed to N-methyl-N-nitrosourea (MNU) at 50 ppm in 10 mM Hepes-buffered synthetic seawater for 2 h. Tumour incidence 4 months after exposure was approximately 95%, and mainly papillary thyroid tumours were induced. For elucidating the molecular event in Rivulus papillary thyroid carcinogenesis, we first analysed for ras gene mutations based on the known ability of MNU to induce point mutations. The amplified R. Marmoratus Ha-and Ki-ras gene exon 1 and 2 regions were checked along with confirming the presence and expression patterns of the DNA repair gene O(6)-methylguanine alkyltransferase (O(6)-MT) and other oncogenes (c-src, c-fos, and c-myc). Ha- and Ki-ras genes from 38 tumour samples were tested for point mutations with direct sequencing but were not found to contain mutations. In this report, based on the lack of Ha- and Ki-ras gene mutations in papillary thyroid tumour induction in R. Marmoratus, we suggest that Ha- and Ki-ras gene-independent pathways such as ret/PTC rearrangements and other activations are involved in Rivulus papillary thyroid carcinogenesis. Teratogenesis Carcinog. Mutagen. 20:1-9, 2000. Copyright 2000 Wiley-Liss, Inc. PMID: 10607373 [PubMed - indexed for MEDLINE] DR281: Oncogene. 1999 Nov 4;18(46):6330-4. Chromosomal breakpoint positions suggest a direct role for radiation in inducing illegitimate recombination between the ELE1 and RET genes in radiation-induced thyroid carcinomas. Nikiforov YE, Koshoffer A, Nikiforova M, Stringer J, Fagin JA. Department of Pathology, University of Cincinnati College of Medicine, OH 45267-0529, USA. The RET/PTC3 rearrangement is formed by fusion of the ELE1 and RET genes, and is highly prevalent in radiation-induced post-Chernobyl papillary thyroid carcinomas. We characterized the breakpoints in the ELE1 and RET genes in 12 post-Chernobyl pediatric papillary carcinomas with known RET/PTC3 rearrangement. We found that the breakpoints within each intron were distributed in a relatively random fashion, except for clustering in the Alu regions of ELE1. None of the breakpoints occurred at the same base or within a similar sequence. There was also no evidence of preferential cleavage in AT-rich regions or other target DNA sites implicated in illegitimate recombination in mammalian cells. Modification of sequences at the cleavage sites was minimal, typically involving a 1-3 nucleotide deletion and/or duplication. Surprisingly, the alignment of ELE1 and RET introns in opposite orientation revealed that in each tumor the position of the break in one gene corresponded to the position of the break in the other gene. This tendency suggests that the two genes may lie next to each other but point in opposite directions in the nucleus. Such a structure would facilitate formation of RET/PTC3 rearrangements because a single radiation track could produce concerted breaks in both genes, leading to inversion due to reciprocal exchange via end-joining. PMID: 10597232 [PubMed - indexed for MEDLINE] DR282: J Formos Med Assoc. 1999 Oct;98(10):692-7. De novo RET proto-oncogene mutation in a patient with multiple endocrine neoplasia type 2B. Chang TJ, Wu SL, Chang TC, Huang SH, Chang TJ. Department of Internal Medicine, En Chu Kong Hospital, Taipei Hsien. We report a case of multiple endocrine neoplasia type 2B (MEN 2B) with de novo RET proto-oncogene mutation. The patient, a 23-year-old Taiwanese woman, was admitted for treatment of recurrent medullary thyroid cancer (MTC) 7 years after a total thyroidectomy. Mucosal neuromas and marfanoid appearance were also noted. Because MEN 2B was suspected, the patient and her family members underwent genetic analysis. A heterozygous germline mutation at codon 918 (ATG-->ACG) of the proto-oncogene RET was detected in the patient. This mutation was considered de novo, as it was not detected in either of her parents or her siblings. The patient underwent surgery for removal of the recurrent tumor. Although no pheochromocytoma was noted, regular follow-up is necessary because of persistent hypercalcitoninemia. Publication Types: Case Reports PMID: 10575840 [PubMed - indexed for MEDLINE] NR283: Am J Pathol. 1999 Nov;155(5):1499-509. Mixed medullary-follicular thyroid carcinoma. Molecular evidence for a dual origin of tumor components. Volante M, Papotti M, Roth J, Saremaslani P, Speel EJ, Lloyd RV, Carney JA, Heitz PU, Bussolati G, Komminoth P. Department of Biomedical Sciences, University of Turin, Turin, Italy. Mixed medullary-follicular carcinomas (MMFCs) are tumors of the thyroid that display morphological and immunohistochemical features of both medullary and follicular neoplasms. The histogenetic origin and possible molecular mechanisms leading to MMFCs are still unclear. To address these questions, we have isolated the two histological components of 12 MMFCs by (laser-based) microdissection, analyzed them for mutations in the RET proto-oncogene and allelic losses of nine loci on six chromosomes, and studied the clonal composition of MMFCs in female patients. Our results provide strong evidence that the follicular and medullary components in MMFCs are not derived from a single progenitor cell, because the seven tumors amenable for analysis consistently exhibited a different pattern of mutations, allelic losses, and clonal composition. We also demonstrate that follicular structures in MMFCs are often oligo/polyclonal and more frequently exhibit hyperplastic than neoplastic histological features, indicating that at least a subset of MMFCs are composed of a medullary thyroid carcinoma containing hyperplastic follicles. PMID: 10550306 [PubMed - indexed for MEDLINE] DR284: Tohoku J Exp Med. 1999 Jun;188(2):177-87. Noncardiogenic pulmonary edema as the chief manifestation of a pheochromocytoma: a case report of MEN 2A with pedigree analysis of the RET proto-oncogene. Okada Y, Suchi M, Takeyama H, Hodgson ME, Kato T, Manabe T. The First Department of Surgery, Nagoya City University Medical School, Nagoya, Japan. yuji@igaku.med.nagoya-cu.ac.jp Pheochromocytomas are rare neoplasias of the adrenal medulla which generally present with paroxysmal or sustained hypertension. Cardiogenic pulmonary edema is a common feature of these tumors, but few cases have been described with noncardiogenic pulmonary edema. We report a pheochromocytoma with the principle manifestation of noncardiogenic pulmonary edema and characterize a genetic lesion associated with the disorder. A 30-year-old man was admitted with abdominal pain and breathlessness. x-Ray examination of the chest revealed a massive, diffuse infiltration of the left lung without cardiomegaly. No paroxysmal blood pressure fluctuations or heart failure were evident during the entire course, and the infiltrate and dyspnea resolved in three days without inotropic or diuretic agents. Serum norepinephrine and epinephrine levels were elevated twenty and fifty times above normal, respectively. The patient was ultimately diagnosed with multiple endocrine neoplasia type 2A (MEN 2A). Mutations in the RET proto-oncogene have been described recently in patients with MEN 2A. Mutation analysis of selected RET exonic sequences identified a germline mutation at codon 634 in exon 11 of the RET proto-oncogene. The mutation introduces a transition encoding a non-conservative substitution from TGC (Cys) to CGC (Arg) and creates a novel restriction site recognized by HhaI. We further screened for this mutation among four of the proband's relatives by HhaI restriction analysis. One asymptomatic family member was identified who subsequently elected prophylactic total thyroid removal. Histological examination of this specimen confirmed the presence of medullary thyroid carcinoma. Publication Types: Case Reports PMID: 10526879 [PubMed - indexed for MEDLINE] DR285: J Clin Endocrinol Metab. 1999 Oct;84(10):3522-7. A novel case of multiple endocrine neoplasia type 2A associated with two de novo mutations of the RET protooncogene. Tessitore A, Sinisi AA, Pasquali D, Cardone M, Vitale D, Bellastella A, Colantuoni V. Dipartimento di Biochimica e Biotecnologie Mediche e Ceinge, Centro di Ingegneria Genetica, Universita degli Studi di Napoli Federico II, Italy. We report a novel case of multiple endocrine neoplasia type 2A (MEN 2A) associated with two mutations of the protooncogene RET. One affects codon 634 and causes a cysteine to arginine substitution; the second at codon 640 causes an alanine to glycine substitution in the transmembrane region. The two mutations were present on the same RET allele and were detected in germline and tumor DNA. Both mutations were de novo, i.e. they were not found in the DNA of the parents or relatives. Immunohistochemical and RT-PCR analysis showed that the pheochromocytoma expressed calcitonin as well as both RET alleles. A cell line established from the tumor and propagated in culture sustained the expression of RET and calcitonin, as did the original pheochromocytoma. Because the patient presented with medullary thyroid carcinoma and pheochromocytoma without parathyroid gland involvement, we speculate that this clinical picture could be correlated with the two RET mutations and to the unusual calcitonin production. This is the first report of a MEN 2A case due to two mutations of the RET gene and associated with a calcitonin-producing pheochromocytoma. Publication Types: Case Reports PMID: 10522989 [PubMed - indexed for MEDLINE] NR286: Chirurg. 1999 Sep;70(9):987-98. [Thyroidectomy and lymphadenectomy] [Article in German] Buhr HJ, Mann B. Chirurgische Klinik I, Universitatsklinikum Benjamin Franklin, FU Berlin. In benign goiter, thyroidectomy is only indicated in patients with nodular alterations of the complete thyroid gland. There is no evidence indicating that total thyroidectomy could improve the postoperative results in patients with Graves' disease. In Germany, thyroidectomy with cervicocentral lymph node dissection is the standard procedure for all differentiated thyroid carcinomas. However, there are no data to prove that this approach is superior to less radical procedures. Avoidance of reoperations and optimal conditions for effective postoperative radioiodine therapy are arguments for this aggressive strategy. In patients with medullary carcinoma or with detected ret-proto-oncogene mutations, thyroidectomy with cervicocentral lymphadenectomy should be the initial operation. The cervicolateral and mediastinal compartments should be dissected when clinically obvious lymph node metastases are present in patients with differentiated carcinomas. In patients with medullary carcinomas, persistently increased calcitonin levels after the initial operation are sufficient indication for this procedure. Thyroidectomy is an important part of the multimodal approach in patients with anaplastic carcinomas. The operative technique of thyroidectomy is presented as well as the technique of cervical lymphadenectomy in consideration of the lymphatic drainage of the thyroid gland. Publication Types: Review Review, Tutorial PMID: 10501663 [PubMed - indexed for MEDLINE] DR287: Oncogene. 1999 Aug 26;18(34):4833-8. The Glu632-Leu633 deletion in cysteine rich domain of Ret induces constitutive dimerization and alters the processing of the receptor protein. Bongarzone I, Vigano E, Alberti L, Mondellini P, Uggeri M, Pasini B, Borrello MG, Pierotti MA. Division of Experimental Oncology A, Instituto Nazionale Tumori, 20133 Milan, Italy. Mutations of the RET gene, encoding a receptor tyrosine kinase, have been associated with the inherited cancer syndromes MEN 2A and MEN 2B. They have also further been associated with both familial and sporadic medullary thyroid carcinomas. Missense mutations affecting cysteine residues within the extracellular domain of the receptor causes constitutive tyrosine kinase activation through the formation of disulfide-bonded homodimers. We have recently reported that a somatic 6 bp in-frame deletion, originally coding for Glu632-Leu633, potently activates the RET gene. This activation is increased with respect to the frequent MEN 2A-associated missense mutation Cys634Arg. This finding specifically correlated to the clinic behavior of the corresponding tumor, which was characterized by an unusually aggressive progression with both multiple and recurrent metastases. By examining the possibility that this deletion acts in a manner similar to cysteine substitution, we have analysed the molecular mechanism by which this oncogenic activation occurs. Phosphorylated dimers of the deleted Ret receptor were detected in immunoprecipitates separated under non-reducing conditions. Like other Cys point mutations, this 6 bp deletion affecting two amino acid residues between two adjacent Cys, is capable of activating the transforming ability of Ret by promoting receptor dimerization. These results suggest that alteration to cysteine residue position or pairing is capable of inducing ligand independent dimerization. Furthermore, we present data demonstrating that the processing and sorting of the Ret membrane receptor to the cell surface is affected by mutation type. PMID: 10490816 [PubMed - indexed for MEDLINE] DR288: Surg Today. 1999;29(9):862-7. Presymptomatic detection and treatment of Japanese carriers of the multiple endocrine neoplasia type 2A gene. Uchino S, Noguchi S, Sato M, Adachi M, Yamashita H, Watanabe S, Murakami T, Toda M, Murakami N, Yamashita H. Noguchi Thyroid Clinic and Hospital Foundation, Beppu, Oita, Japan. DNA extracted from the peripheral blood leukocytes of 36 members of five families with multiple endocrine neoplasia (MEN) type 2A was analyzed for mutations of exons 10, 11, 13, 14, and 16 of the RET proto-oncogene by nonisotopic polymerase chain reaction-single-strand conformation polymorphism analysis and automated DNA sequencing. Germline mutations were found in all 9 of the affected individuals and in 6 of the 27 individuals of unknown status. A 70-year-old man who had been completely asymptomatic before genetic diagnosis underwent left adrenalectomy and total thyroidectomy, and was found to have pheochromocytoma and multifocal micromedullary thyroid carcinoma (MTC). A 32-year-old man and a 15-year-old boy, with elevated calcitonin levels detected by the C-cell-stimulation test, but no evident thyroid tumor, underwent total thyroidectomy. Histopathological diagnosis revealed multiple micro MTCs. A 7-year-old girl without evidence of a thyroid tumor or an elevated calcitonin level is being followed up. The remaining two subjects with an evident thyroid tumor and elevated calcitonin levels refused surgery. These results suggest that genetic screening for MEN type 2 afflicted family members can facilitate the presymptomatic detection of gene carriers. Thus, we must carefully evaluate whether immediate prophylactic total thyroidectomy is indicated for gene carriers of MEN 2A without an evident thyroid tumor or elevated calcitonin levels. PMID: 10489126 [PubMed - indexed for MEDLINE] DR289: J Pediatr. 1999 Sep;135(3):327-31. Familial medullary thyroid carcinoma: presymptomatic diagnosis and management in children. Heptulla RA, Schwartz RP, Bale AE, Flynn S, Genel M. Department of Pediatrics, Yale University School of Medicine, New Haven, Connecticut 06520-8000, USA. Two kindreds with familial medullary thyroid carcinoma (MTC) are described in which affected family members had variable clinical and pathologic manifestations. Genetic testing in 2 children from one kindred revealed a mutation in exon 10, codon 618 (TGC to AGC) in the extracellular cysteine-rich region of the RET gene. In this kindred an 11-year-old had microscopic evidence of MTC; however, a 17-year-old had no evidence of pathology on thyroidectomy. In a second kindred a rare mutation in exon 14, codon 804 (GTG to TTG) of the intracellular tyrosine kinase region of the RET gene was detected. In this kindred MTC has occurred in the 4th to 5th decades of life, with a clinical spectrum in mutation-positive family members ranging from no disease and C-cell hyperplasia to carcinoma with lymph node metastasis; a 7-year-old with the mutation and a normal response to provocative testing was also identified. Management recommendations in children from families with clearly defined familial MTC may be individualized to reflect emerging genotype-phenotype correlations. Publication Types: Case Reports PMID: 10484798 [PubMed - indexed for MEDLINE] NR290: Eur J Endocrinol. 1999 Sep;141(3):286-9. Incidental detection of familial medullary thyroid carcinoma by calcitonin screening for nodular thyroid disease. Mayr B, Brabant G, von zur Muhlen A. Department of Clinical Endocrinology, Medizinische Hochschule Hannover, 30623 Hannover, Germany. Serum calcitonin screening has recently been found to be a useful supplement to fine-needle aspiration biopsy, ultrasound and radionuclide imaging in the evaluation of thyroid nodules. We describe a case where introduction of routine calcitonin screening in nodular thyroid disease led to the detection of a family with medullary thyroid carcinoma. The benefits and problems of basal and stimulated serum calcitonin testing and ret-proto-oncogene mutation studies are exemplified and we discuss the appropriate use and interpretation of these tests. We conclude that routine basal serum calcitonin measurement in nodular thyroid disease and thoughtful use of ret-mutation analysis is cost-effective in detecting medullary thyroid carcinoma and multiple endocrine neoplasia type II. Publication Types: Case Reports PMID: 10474127 [PubMed - indexed for MEDLINE] DR291: Cancer Res. 1999 Aug 15;59(16):3911-4. Hammerhead ribozyme-mediated inactivation of mutant RET in medullary thyroid carcinoma. Parthasarathy R, Cote GJ, Gagel RF. Department of Internal Medicine Specialties, The University of Texas M.D. Anderson Cancer Center, Houston 77030, USA. Activating mutations of the RET proto-oncogene cause hereditary medullary thyroid carcinoma. To examine whether selective inactivation of mutant RET could prevent transformation, a hammerhead ribozyme was designed to cleave RET mRNA containing a transforming mutation of codon 634 TGC --> TAC (Cys634Tyr). In vitro RNA cleavage assay demonstrated that the ribozyme selectively cleaved RET RNA with a Cys634Tyr but not Cys634Arg or the normal sequence. Expression of ribozyme in NIH/3T3 cells prevented RET-mediated colony formation in soft agar. This inhibition required catalytically active ribozyme and was specific for the TAC mutation. Therefore, ribozymes designed to selectively target mutant RET RNA may provide an effective therapeutic in the treatment of this syndrome. PMID: 10463581 [PubMed - indexed for MEDLINE] DR292: Mol Diagn. 1997 Dec;2(4):277-286. Age-Related Disease Penetrance in a Large Medullary Thyroid Cancer Family With a Codon 609 RET Gene Mutation. Halling KC, Bufill JA, Cotter M, Artz SA, Carpenter AB, Schaid D, Hartman-Adams H, Chang HH, Boustany MM, Fithian L, Jhiang SM, Thibodeau SN. Department of Laboratory Medicine and Pathology, Mayo Foundation, Rochester, Minnesota, USA Background: Familial medullary thyroid cancer (MTC) is a form of type 2 multiple endocrine neoplasia in which individuals develop MTC as the sole phenotypic manifestation of their disease. A previous study has suggested that patients with familial MTC may have a later age of onset (and more indolent course) of MTC than is observed in individuals with multiple endocrine neoplasia type 2A. Methods and Results: The age-related penetrance of MRC, C-cell hyperlasia, and a positive pentagastrin test for carriers of a codon 609 mutation of the RET gene in a large MTC family was determined. Pentagastrin testing and surgical pathology findings for patients who had thyroidectomies were correlated with RET sequence analysis findings. The penetrance of this mutation for the development of MTC was 0% at age 20, 10% at age 20, 10% at age 30, 50% at age 45, and approximately 100% at age 60. The ages of onset of C-cell hyperplasia and a positive pentagastrin stimulation test were similar, and both preceded the age of onset of MTC. Carriers of the mutated gene in this family had a later age of onset of disease that has been reported for families with multiple endocrine neoplasia type 2A and 2B syndromes. Conclusions: These results may have implications for the clinical management of MTC families with a 609 mutation. PMID: 10462620 [PubMed - as supplied by publisher] DR293: J Clin Oncol. 1999 Jan;17(1):380-93. RET proto-oncogene in the development of human cancer. Eng C. Department of Adult Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA. eng-1@medctr.osu.edu The RET proto-oncogene, located on chromosome subband 10q11.2, encodes a receptor tyrosine kinase expressed in tissues and tumors derived from neural crest. Germline (present in every cell of the body) mutations in RET cause multiple endocrine neoplasia type 2 (MEN 2), an inherited cancer syndrome characterized by medullary thyroid carcinoma (MTC), pheochromocytoma (PC), and hyperparathyroidism (HPT). This knowledge has allowed molecular diagnosis and presymptomatic DNA-based testing to become possible. RET testing is considered the standard of care in MEN 2 families because clinical decisions are made based on the results of such gene testing. There appears to be a correlation between specific RET mutation type and organ-specific tumor development. Such knowledge might be useful in tailoring targeted surveillance in the near future. Somatic (in the tumor only) RET mutations have been found in a proportion of sporadic MTCs and PCs. Whether the presence of somatic RET mutation is associated with a poor prognosis is currently being investigated as another tool for molecular medicine. Publication Types: Review PMID: 10458257 [PubMed - indexed for MEDLINE] DR294: Oncogene. 1999 Jul 1;18(26):3919-22. Biological and biochemical properties of Ret with kinase domain mutations identified in multiple endocrine neoplasia type 2B and familial medullary thyroid carcinoma. Iwashita T, Kato M, Murakami H, Asai N, Ishiguro Y, Ito S, Iwata Y, Kawai K, Asai M, Kurokawa K, Kajita H, Takahashi M. Department of Pathology, Nagoya University School of Medicine, Japan. Several mutations were identified in the kinase domain of the RET proto-oncogene in patients with multiple endocrine neoplasia (MEN) 2B, familial medullary thyroid carcinoma (FMTC) or sporadic medullary thyroid carcinoma. We introduced seven mutations (glutamic acid 768-->aspartic acid (E768D), valine 804-->leucine (V804L), alanine 883-->phenylalanine (A883F), serine 891-->alanine (S891A), methionine 918-->threonine (M918T), alanine 919-->proline (A919P) and E768D/A919P) into the short and long isoforms of RET cDNA and transfected the mutant cDNAs into NIH3T3 cells. The transforming activity of the long isoform of Ret with each mutation was much higher that that of its short isoform. Based on the levels of the transforming activity, these mutant RET genes were classified into two groups; a group with high transforming activity (A883F, M918T and E768D/A919P) and a group with low transforming activity (E768D, V804L, S891A and A919P) (designated high group and low group). Interestingly, the level of transforming activity correlated with clinical phenotypes; high group Ret with the A883F or M918T mutation and low group Ret with the E768D, V804L or S891A mutation were associated with the development of MEN 2B and FMTC, respectively. In addition, we found that substitution of phenylalanine for tyrosine 905 present in the kinase domain abolished both transforming and autophosphorylation activities of low group Ret whereas it did not affect the activities of high group Ret. PMID: 10445857 [PubMed - indexed for MEDLINE] PR295: J Clin Endocrinol Metab. 1999 Aug;84(8):2784-7. Mutation analysis reveals novel sequence variants in NTRK1 in sporadic human medullary thyroid carcinoma. Gimm O, Greco A, Hoang-Vu C, Dralle H, Pierotti MA, Eng C. Comprehensive Cancer Center, Ohio State University, Columbus 43210, USA. Tyrosine kinase NTRK1 is expressed in neural and nonneuronal tissues. Like RET, NTRK1 is often activated by rearrangements that involve one of at least five other genes in papillary thyroid carcinoma (PTC). Because of similarities in involvement of the two tyrosine kinases RET (rearranged during transfection) and NTRK1 in the pathogenesis of PTC, the obvious parallels between RET and NTRK1 and between PTC and medullary thyroid carcinoma (MTC), NTRK1 seemed to be an excellent candidate gene to play a role in the genesis of MTC. Single-strand conformational polymorphism analysis of 16 exons of NTRK1, from 31 sporadic MTC, revealed variants in five exons (exons 4 and 14-17). Sequence analysis demonstrated one sequence variant each in exons 4, 14, 16, and 17, and four different variants in exon 15. Differential restriction enzyme digestion specific for each variant confirmed the sequencing results. All variants were also present in the corresponding germline DNA. Interestingly, the sequence variants at codon 604 (c1810C>T) and codon 613 (c1838G>T) ofexon 15 always occurred together and might represent linkage disequilibrium. The frequencies of the sequence variants in germline DNA from patients with sporadic MTC did not differ significantly from those in a race-matched control group. Although we did not find any somatic mutations of NTRK1 in sporadic MTC, the single-strand conformational polymorphism conditions reported here, together with the knowledge of the frequency of various sequence variants, may help in future mutation analyses of DNA from other neural and nonneural tissues. PMID: 10443680 [PubMed - indexed for MEDLINE] DR296: Hinyokika Kiyo. 1999 Jun;45(6):407-10. [A case of multiple endocrine neoplasia type 2A (MEN2A) with a mutation in the RET gene] [Article in Japanese] Ishizu K, Shiraishi K, Kawamura H, Naito K, Takahashi T, Yoshimura K, Tangoku A, Shirahama S. Department of Urology, Yamaguchi University School of Medicine. A 44-year-old woman complained of headache and palpitation. Magnetic resonance imaging showed bilateral adrenal tumors 10 x 9 cm in size on the left side and 8 x 4 cm in size on the right side. CT scan revealed a 0.7 x 0.7 cm mass in the thyroid. Hormonal examinations showed high values of urinary cathecholamines and serum calcitonin. DNA sequence analysis of peripheral white blood cells revealed that codon 634 in exon 11 of the RET gene was mutated from TGC (Cys) to TAC (Tyr). From these findings, a diagnosis was made of MEN2A with bilateral adrenal pheochromocytomas and medullary thyroid carcinoma. Bilateral adrenalectomy and thyroidectomy were performed. The same mutation of the RET gene was detected in all her 3 children, in two of whom, early stage medullary thyroid carcinoma was detected and thyroidectomy was performed. DNA analysis of the RET gene was useful for the diagnosis of carriers of MEN2A and the early detection of medullary thyroid carcinoma. Publication Types: Case Reports PMID: 10442282 [PubMed - indexed for MEDLINE] DR297: Endocr J. 1999 Feb;46(1):199-207. Infrequent detectable somatic mutations of the RET and glial cell line-derived neurotrophic factor (GDNF) genes in human pituitary adenomas. Yoshimoto K, Tanaka C, Moritani M, Shimizu E, Yamaoka T, Yamada S, Sano T, Itakura M. Otsuka Department of Clinical and Molecular Nutrition, The University of Tokushima, Tokushima-city, Japan. RET is a receptor tyrosine kinase expressed in neuroendocrine cells and tumors. RET is activated by a ligand complex comprising glial cell line-derived neurotrophic factor (GDNF) and GDNF receptor-alpha (GDNFR-alpha). Activating mutations of the RET proto-oncogene were found in multiple endocrine neoplasia (MEN) 2 and in sporadic medullary thyroid carcinoma and pheochromocytoma of neuroendocrine origin. Mutations of the RET proto-oncogene and the glial cell line-derived neurotrophic factor (GDNF) gene were examined in human pituitary tumors. No mutations of the RET proto-oncogene including the cysteine-rich region or codon 768 and 918 in the tyrosine kinase domain were detected in 172 human pituitary adenomas either by polymerase chain reaction (PCR)-single strand conformation polymorphism (SSCP) or by PCR-restriction fragment length polymorphism (RFLP). Further, somatic mutations of the GDNF gene in 33 human pituitary adenomas were not detected by PCR-SSCP. One polymorphism of the GDNF gene at codon 145 of TGC or TGT was observed in a prolactinoma. The RET proto-oncogene message was detected in a normal human pituitary gland or 4 of 4 human pituitary adenomas with reverse transcription (RT)-PCR, and in rodent pituitary tumor cell lines with Western blotting. The expression of GDNF gene was detected in 1 of 4 human somatotroph adenomas, 1 of 2 corticotroph adenomas, and 2 of 6 rodent pituitary tumor cell lines with RT-PCR. Based on these, it is concluded that somatic mutations of the RET proto-oncogene or the GDNF gene do not appear to play a major role in the pituitary tumorigenesis in examined tumors. PMID: 10426588 [PubMed - indexed for MEDLINE] NR298: Rev Med Interne. 1999 Jun;20(6):490-503. Erratum in: Rev Med Interne 2000 Jan;21(1):15. [Medullary cancer of the thyroid] [Article in French] Modigliani E. Service d'endocrinologie, hopital Avicenne, Bobigny, France. INTRODUCTION: Medullary thyroid carcinoma is a rare disease which originates from the secretion of calcitonin by thyroid parafollicular cells. Sporadic (75%) and inherited (25%) forms of the disease are encountered. Familial forms (termed multiple endocrine neoplasia type IIa, IIb, or familial medullary thyroid carcinoma) may or may not be associated with other endocrinopathies such as pheochromocytoma and/or hyperparathyroidism. CURRENT KNOWLEDGE AND KEY POINTS: Circulating forms of calcitonin, a marker of the disease, are heterogeneous in blood, thus explaining why assays lead to different results according to the method used. FUTURE PROSPECT AND PROJECTS: Family screening is much easier, as germ line mutations of the proto-oncogene RET have recently been identified in inherited forms of the disease. Treatment includes extensive surgery. This, and prophylactic thyroidectomy in gene carriers, is discussed. Prognosis is much better nowadays, but precise follow-up has to be instituted. Publication Types: Review Review, Tutorial PMID: 10422141 [PubMed - indexed for MEDLINE] DR299: Biochimie. 1999 Apr;81(4):397-402. Different mutations of the RET gene cause different human tumoral diseases. Santoro M, Melillo RM, Carlomagno F, Visconti R, De Vita G, Salvatore G, Fusco A, Vecchio G. Centro di Endocrinologia ed Oncologia Sperimentale del CNR/Dipartimento di Biologia e Patologia Cellulare e Molecolare, Universita' di Napoli Federico II, Naples, Italy. The RET gene encodes a tyrosine kinase receptor for neurotrophic molecules. RET is a conceptually valuable example of how different mutations of a single gene may cause different diseases. Gene rearrangements activate the oncogenic potential of RET in human thyroid papillary carcinomas. On the other side, different point mutations activate RET in familial multiple endocrine neoplasia syndromes. Finally, inactivating mutations of RET can be present in Hirschsprung's disease patients. The detailed knowledge of the specific RET mutations responsible for human tumors provides relevant tools for the clinical management of these diseases. Moreover, the recent discovery of the growth factors which in vivo stimulate its signaling may shed new light on the role played by RET in the development and differentiation of the central and peripheral nervous system. Publication Types: Review Review, Tutorial PMID: 10401675 [PubMed - indexed for MEDLINE] PR300: Am J Pathol. 1999 Jul;155(1):7-9. Genetics and clinicopathological findings in thyroid carcinomas associated with familial adenomatous polyposis. Cetta F, Pelizzo MR, Curia MC, Barbarisi A. Publication Types: Review Review, Tutorial PMID: 10393829 [PubMed - indexed for MEDLINE]