Division of Toxicology, Department of Pharmacology and Toxicology, Indiana University School of Medicine, 635 Barnhill Dr., MS 1021, Indianapolis, Indiana 46202
Received June 7, 2001; accepted September 25, 2001
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ABSTRACT |
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Key Words: acrylamide; carcinogenicity; oxidative stress; Syrian hamster embryo (SHE) cells; morphological transformation.
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INTRODUCTION |
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Chromosomal aberrations and sister chromatid exchanges were observed in vitro with acrylamide treatment (Adler et al., 2000; Tsuda et al., 1993
). Although acrylamide binds to DNA directly via a Michael addition reaction in vitro (Solomon et al., 1985
) and in vivo (Segerbäck et al., 1995
), acrylamide failed to produce mutagenicity in bacterial mutagenesis systems, either in the presence or in the absence of S9 mix for metabolic activation (Hashimoto and Tani, 1985).
Acrylamide appears to be metabolized into glycidamide via P450 2E1 (Calleman et al., 1990; Sumner et al., 1999
), forming a DNA-reactive epoxide that implies genotoxicity (Segerbäck et al., 1995
). However, the tissue and organ distribution of DNA-glycidamide adducts do not correlate with acrylamide-induced tumors in rat organs (Segerbäck et al., 1995
). Additional studies have failed to show mutation activity by acrylamide except for clastogenic activity in germ cells (Hashimoto and Tani, 1985; Tsuda et al., 1993
). Thus, it is possible that nongenotoxic or epigenetic mechanisms may participate in acrylamide-induced tumorigenicity in rodents. One possible epigenetic mode of action may be related to the affinity of acrylamide for sulfhydryl groups in the cell and in glutathione (GSH, the thiols of nonprotein), specifically. Acrylamide is detoxified by conjugation with GSH. This may result in a depletion of cellular GSH stores and result in a change in the redox status of the cell. This change, in turn, may modulate gene expression directly or via the transcription factors that are redox-regulated, and may lead to apoptosis, cell proliferation, or transformation (Abate et al., 1990
; Schulze-Ostoff et al., 1995). Acrylamide also binds to cysteine residues of proteins (Hashimoto and Aldridge, 1970
; Miller et al., 1982
; Srivastava et al., 1986
). Acrylamide reactivity with enzymes or receptors may induce changes in cellular functions and signal pathways, leading to a possible involvement with acrylamide-induced carcinogenesis. Changes in dopamine receptor affinity and alterations of thyroid stimulating hormones, prolactin, and testosterone levels have been observed in rats following acrylamide treatment (Agrawal et al., 1981
; Ali et al., 1983
). Prolonged hormonal derangement is associated with the induction of mutations and the carcinogenic process (Furth, 1975
), and the tumors observed following chronic treatment were localized to endocrine-sensitive organs. Acrylamide also binds to cytoskeletal proteins (Hartley et al., 1997
; Sickles et al., 1995). Disruption of the cytoskeletal system has been documented in neoplastic cells and reflects the altered shape and altered motility of the transformed cells (Pienta and Coffey, 1992
). Cytoskeletal disruption by the carcinogenic process can alter growth-related cellular function (Liaw and Schwartz, 1993
; Pienta and Coffey, 1992
).
Morphological transformation of Syrian hamster embryo (SHE) cells mimics the early stage of carcinogenesis, while established cell lines BALB/c3T3 and C3H/10T1/2 cells are considered to represent later stages of the carcinogenesis process (Yamasaki et al., 1996). Acrylamide has previously been shown to induce morphological transformation in C3H/10T1/2 and NIH/3T3 cells (Banerjee and Segal, 1986
) as well as in the BALB/c3T3 cell line (Tsuda et al., 1993
). Transformation of SHE cells has been widely used in studies examining the mechanisms of chemical carcinogenesis (Barrett et al., 1984
; Isfort et al., 1994
). In the present study we specifically addressed whether: (1) acrylamide can induce transformation in SHE cells, (2) P450 metabolism of acrylamide was necessary to produce the cellular transformation, (3) modulation of GSH levels in SHE cells produced a change in cell transformation by acrylamide, and (4) possible interaction of 17-ß-estradiol on acrylamide-induced transformation (Kaster et al., 1997
) could be observed upon further examination of preliminary findings.
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MATERIALS AND METHODS |
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Cell culture.
SHE cells were isolated and cultured as described previously (Kerckaert et al., 1996). Briefly, primary embryo cells were isolated from 13-day gestation Syrian golden hamsters (Charles River, Wilmington, MA) and cryopreserved. The primary cells were grown in Le Boeuf's Dulbecco's modified eagle medium (pH 6.7), supplemented with 20% fetal bovine serum and 4 mM L-glutamate at 37°C in 10% CO2 at 90% relative humidity. A feeder layer was prepared by plating 2 x 106 SHE cells into 30 ml of complete media in a T-150 tissue culture flask. After a 48-h incubation, the cells were detached with 0.05% trypsin and 0.02% Na2EDTA in Ca+2-, Mg+2-free Hank's balanced salt solution (HBSS). The cells were irradiated (5000 rads) on ice for 40 min, and plated at a density of 4 x 104 cells/60-mm culture dish in 2 ml of medium. The target cells were prepared by plating 1 x 106 thawed cells per T-25 tissue culture flask containing 5 ml of complete media. After a 24-h incubation, the cells were detached with trypsin/Na2EDTA and plated onto the feeder layer at a density of 6080 cells/60-mm culture dish with 2 ml of medium, giving a total volume of 4 ml. After a 24-h incubation, cells were continuously exposed to acrylamide, with and without the other test compounds. In addition, for NAC treatment of SHE cells, the pH was adjusted with 1 N NaOH to that of control media. Cells were treated with BSO for 24 h in advance and then coincubated with acrylamide for 6 days. At sampling, the cultures were then rinsed, fixed with methanol, stained with Giemsa (Sigma, St. Louis, MO), and evaluated for the presence of a morphologically transformed phenotype, using a Nikon stereoscopic zoom microscope. A morphologically transformed colony was defined as previously described (Kerckaert et al., 1996
). For each group, total colony number, morphological transformation frequency [(the number of transformed colonies/total number of colonies scored) x 100], and the relative plating efficiency [RPE, (test group plating efficiency/solvent control plating efficiency) x 100] were determined.
Statistics.
Collected data were statistically analyzed by Fisher's exact test for morphological transformation studies. Treatment groups were considered statistically different at p < 0.05 (Armitage, 1971).
Measurement of GSH.
AM-treated cells were washed with PBS, collected by scraping from culture dishes, resuspended with buffer, and analyzed for glutathione (GSH) following the method of Harvey et al. (1989). The suspended cells were treated with perchloric acid (0.1 M) to precipitate proteins. After centrifugation, the supernatant was injected onto HPLC columns. Separation was achieved with 2 radial-pak liquid chromatograph cartridges (8 mm; Waters, Milford, MA) and a mobile phase (2% aqueous acetonitrile, 50 mM sodium phosphate monobasic, and 0.05 mM octanesulfonic acid, pH 3.4, adjusted by 85% phosphoric acid) at a flow rate of 1 ml/min. The GSH amount was measured by electrochemical detection (Coulochem 5200 with 5020 guard cell and 5010 analytical cell; esa, Chelmsford, MA) set at 400 mV potential, 0.5 µA range. GSH concentration was calculated from the GSH standard curve. Protein content of the extracts was determined using Bio-Rad DC protein assay kit that is based on the method of Lowry et al. (1951), with bovine serum albumin as a standard.
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RESULTS |
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1-Aminobenzotriazole (ABT), a nonspecific suicidal P450 inhibitor, was used to block oxidative metabolism of acrylamide through cytochrome P450. The effect of ABT cotreatment with acrylamide on cell transformation is shown in Figure 1. ABT cotreatment with either 0.5 or 0.7 mM acrylamide produced no change in transformation frequency compared with acrylamide only. Treatment with ABT only had no effect on morphological transformation compared to media and DMSO control groups (Fig. 1
).
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DISCUSSION |
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Acrylamide has demonstrated clastogenic properties, having been shown to induce aneuploidy, chromosomal aberrations, and sister chromatid exchange in Chinese hamster V79 cells (Moore et al., 1987; Shiraishi, 1978
; Tsuda et al., 1993
). Other compounds including benzene, estrogen, and estrogen-like compounds that produce aneuploidy and have clastogenic activity in vitro have also demonstrated transformation activity in SHE cells (Gibson et al., 1995
; Hayashi et al., 1996
; Tsutsui and Barrett, 1997
; Tsutsui et al., 1997
).
Inhibition of acrylamide oxidative metabolism P450 enzymes by ABT treatment produced no change in SHE cell transformation frequency, suggesting that oxidative metabolite(s) of acrylamide is not involved in acrylamide-induced SHE cell transformation. Previous studies using cell lines have not addressed the role of metabolite(s) in cell transformation (Banerjee and Segal, 1986; Tsuda et al., 1993
). In a previous study of DNA adduct formation in rodents following acrylamide treatment, the levels of DNA adducts with glycidamide, a DNA reactive epoxide metabolite, were measured. Glycidamide binds to cellular DNA and induces mutagenicity in the Ames test (Hashimoto and Tanii, 1985
). In acrylamide-treated rodents, glycidamide DNA adduct formation was evenly distributed throughout the body in contrast to the observed organ pattern of acrylamide carcinogenicity (Segerbäck et al., 1995
). This suggests that metabolism of acrylamide may not be necessary for DNA adduct formation and its carcinogenic effects and that the parent compound acrylamide may be involved in the carcinogenesis. In addition, the observed toxic effects of acrylamide in in vitro studies with Chinese hamster ovary cells and mouse lymphoma cells without exogenous metabolic activation suggest that metabolism is not involved in the transformational/carcinogenic effect (Tsuda et al., 1993
; Moore et al., 1987
). Our current results support this premise, in that inhibition of P450 metabolism by ABT failed to modify acrylamide-induced cell transformation in the SHE cells. In contrast to this, a recent in vivo study reported that ABT pretreatment inhibited or reduced the dominant lethal effect of acrylamide (125 mg/kg) in mice, suggesting that glycidamide, the epoxide metabolite of acrylamide is the cause of germ cell mutation in mouse spermatids (Adler et al., 2000
). However, in that study it was also suggested that a chromosomal protein of sperm cells is alkylated directly by the parent acrylamide that may be the mechanism of acrylamide-induced clastogenicity. Conversion of acrylamide to glycidamide by cytochrome P450 enzymes is inversely related to the level of parent acrylamide in rats, as determined from hemoglobin adduct formation (Bergmark et al., 1991
). Only 13% of parent compound is converted to glycidamide with a high dose (100 mg/kg) of acrylamide, while 50% is converted to glycidamide with a low dose (5 mg/ml).
The well established reactivity of acrylamide with proteins may also participate in the carcinogenesis process by modifying cellular functions and signal pathways. Acrylamide treatment has been shown to alter dopamine receptor affinity as well as changes in hormonal levels (Agrawal et al. 1981; Srivastava et al., 1986
). These changes have been suggested as a mode of action in the induction of tunica vaginalis mesotheliomas in acrylamide-treated male Fisher rats. Acrylamide disruption of the cytoskeletal proteins may be involved in acrylamide-induced cellular transformation carcinogenicity. Microtubule disruption has been shown to change cellular response and to stimulate DNA synthesis of bovine endothelial cells (Liaw and Schwartz, 1993
). Although cytoskleletal disruption was not examined in the present study, alteration in growth factors' responsiveness to mitogens, cell differentiation, and cytoskeleton has been reported in the SHE cell transformation process (Isfort et al., 1994
). Also, alteration of growth-related cell function has been attributed to altered shape and altered motility in other transformed cells (Isfort et al., 1994
; Pienta and Coffey, 1992
). Acute exposure to acrylamide induced change in thyroid gland morphology in female Fisher rats (Khan et al., 1999
).
Acrylamide has been shown to deplete GSH and inhibit gluthathione S-transferase activity in vitro and in vivo (Srivastava et al., 1986). In the present study, depletion of GSH with pretreatment of BSO-enhanced acrylamide induced transformation frequency. Acrylamide and glycidamide GSH conjugates have been detected in the urine of treated rats. A reduction of cellular GSH level by acrylamide treatment was observed in our study. However, the reduction of GSH levels by BSO treatment only did not result in transformation, suggesting that GSH depletion by itself was not sufficient to induce cell transformation. Therefore, acrylamide must have additional properties in the transformation process besides strictly GSH depletion. However, maintenance of GSH levels with NAC prevented the induction of acrylamide cell transformation supporting an important role for GSH in the acrylamide-induced transformation process.
17ß-Estradiol treatment alone showed a tendency to induce morphological transformation frequency in SHE cells (p = 0.066), while cotreatment with 17ß-estradiol and acrylamide induced a synergistic effect on the increase in morphological transformation frequency. Estrogen and estrogen-like chemicals are able to transform SHE cells (Barret et al., 1981; Metzler and Schiffmann, 1991; Tsutui et al., 1987). However, nonhormonal mechanisms are involved in estrogen-induced SHE cell morphological transformation, since there are no measurable levels of estrogen receptors in SHE cells (Korach and McLachlan, 1985
) and no correlation between hormonal potency and the ability of SHE cell morphological transformation (McLachlan et al., 1982
). Estrogen binding to tubulin (Epe et al., 1987
), DNA adduct formation by estrogens and metabolites in vivo and in vitro (Cavalieri et al., 1997
; Stack et al., 1996
), and induction of aneuploidy (Tsutsui et al., 1983
,1987
) have been suggested as alternate mechanisms for cell transformation and carcinogenesis by 17ß-estradiol. These cellular effects by estrogens are similar to those seen with acrylamide.
In summary, acrylamide treatment for 7 days continuously induced morphological transformation in SHE cells. Cotreatment with 17ß-estradiol and acrylamide produced an additive effect on morphological transformation frequency in SHE cells. Acrylamide itself, but not an oxidative metabolite(s) appears to be involved in the SHE cell transformation. Decrease of GSH by acrylamide treatment or by BSO treatment played a role in acrylamide-induced transformation in SHE cells since conjugation of acrylamide to GSH is a detoxification pathway of acrylamide, protecting SHE cells from morphological transformation. Therefore, we propose that clastogenic activity of acrylamide as well as acrylamide reactivity to macromolecules leading to structural and cellular functional change via GSH depletion in SHE cells might be involved in acrylamide-induced SHE cell morphological transformation. Modification of GSH has been shown to participate in cell signaling, subsequently affecting and modifying gene expression (Allen and Tresini, 2000; Trosko et al., 1998
). Further detailed examination of the role of GSH and GSH transferases would help further delineate the mechanisms of acrylamide-induced transformation/carcinogenicity.
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NOTES |
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REFERENCES |
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---|
Adler, I. D., Baumgartner, A., Gonda, H., Friedman, M. A., and Skerhut, M. (2000). 1-Aminobenzotriazole inhibits acrylamide-induced dominant lethal effects in spermatids of male mice. Mutagenesis 15, 133136.
Agrawal, A. K., Seth, P. K., Squibb, R. E., Tilson, H. A., Uphouse, L. L., and Bondy, S. C. (1981) Neurotransmitter receptors in brain regions of acrylamide-treated rats: I. Effects of a single exposure to acrylamide. Pharmacol. Biochem. Behav. 14, 527531.[ISI][Medline]
Ali, S. F., Hong, J. S., Wilson, W. E., Uphouse, L. L., and Bondy, S. C. (1983) Effect of acrylamide on neurotransmitter metabolism and neuropeptide levels in several brain regions and upon circulating hormones. Arch. Toxicol. 52, 3543.[ISI][Medline]
Allen, R. G., and Tresini, M. (2000). Oxidative stress and gene regulation. Free Radic. Biol. Med. 28, 463499.[ISI][Medline]
Armitage, P. (1971). Statistical Methods in Medical Research, pp. 135138. Blackwell Scientific Publications, Oxford, UK.
Banerjee, S., and Segal, A. (1986). In vitro transformation of C3H/10T1/2 and NIH/3T3 cells by acrylonitrile and acrylamide. Cancer Lett. 32, 293304.[ISI][Medline]
Barrett, J. C., Hesterberg, T. W., and Thomassen, D. G. (1984). Use of cell transformation systems for carcinogenicity testing and mechanistic studies of carcinogenesis. Pharmacol. Rev. 6(Suppl.), 5370S.
Barrett, J. C., Wong, A., and McLachlan, J. A. (1981). Diethylstilbestrol induces neoplastic transformation without measurable gene mutation at two loci. Science 212, 14021404.[ISI][Medline]
Bergmark, E., Calleman, C. J., and Costa, L. G. (1991). Formation of hemoglobin adducts of acrylamide and its epoxide metabolite glycidamide in the rats. Toxicol. Appl. Pharmacol. 111, 352363.[ISI][Medline]
Bull, R. J., Robinson, M., Laurie, R. D., Stoner, G. D., Greisiger, E., Meier, J. R., and Stober, J. (1984a). Carcinogenic effects of acrylamide in SENCAR and A/J mice. Cancer Res. 44, 107111.[Abstract]
Bull, R. J., Robinson, M., and Stober, J. A. (1984b). Carcinogenic activity of acrylamide in the skin and lung of Swiss-ICR mice. Cancer Lett. 24, 209212.[ISI][Medline]
Calleman, C. J., Bergmark, E., and Costa, L. G. (1990). Acrylamide is metabolized to glycidamide in the rat: Evidence from hemoglobin adduct formation. Chem. Res. Toxicol. 3, 406412.[ISI][Medline]
Cavalieri, E. L., Stack, D. E., Devanesan, P. D., Todorovic, R., Dwivedy, I., Higginbotham, S., Johansson, S. L., Patil, K. D., Gross, M. L., Gooden, J. K., Ramanathan, R., Cerny, R. L., and Rogan, E. G. (1997). Molecular origin of cancer: Catechol estrogen-3,4-quinones as endogenous tumor initiators. Proc. Natl. Acad. Sci. U.S.A., 94, 1093710942.
Dearfield, K. L., Abernathy, C. O., Ottley, M. S., Brantner, J. H., and Hayes, P. F. (1988). Acrylamide: Its metabolism, developmental and reproductive effects, genotoxicity, and carcinogenicity. Mutat. Res. 195, 4577.[ISI][Medline]
Epe, B., Hegler, J., and Metzler, M. (1987). Site-specific covalent binding of stilbene-type and steroidal estrogens to tubulin following metabolic activation in vitro. Carcinogenesis 8, 12711275.[Abstract]
Friedman, M. A., Dulak, L. H., and Stedham, M. A. (1995). A lifetime oncogenicity study in rats with acrylamide. Fundam. Appl. Toxicol. 27, 95105.[ISI][Medline]
Furth, J. (1975). Hormones as etiological agents in neoplasia. In CancerA Comprehensive Treatise (F.F. Becker, Ed.), Vol. 1, pp. 75120. Plenum, New York.
Gibson, D. P., Aardema, M. J., Kerckaert, G. A., Carr, G. J., Brauninger, R. M., and LeBoeuf, R. A. (1995). Detection of aneuploidy-inducing carcinogens in the Syrian hamster embryo (SHE) cell transformation assay. Mutat. Res. 343, 724.[ISI][Medline]
Hartley, C. L., Anderson, V. E., Anderton, B. H., Robertson, J., and Anderson, B. H. (1997). Acrylamide and 2,5-hexanedione induce collapse of neurofilaments in SH-SY5Y human neuroblastoma cells to form perikaryal inclusion bodies. Neuropathol. Appl. Neurobiol. 23, 364372.[ISI][Medline]
Harvey, P. R., Ilson, R. G., and Strasberg, S. M. (1989). The simultaneous determination of oxidized and reduced glutathiones in liver tissue by ion-pairing reverse-phase high-performance liquid chromatography with a coulometric electrochemical detector. Clin. Chem. Acta 180, 203212.[ISI][Medline]
Hashimoto, K., and Aldridge, W. N. (1970). Biochemical studies on acrylamide, a neurotoxic agent. Biochem. Pharmacol. 19, 25912604.[ISI][Medline]
Hashimoto, K., and Tanii, H. (1985). Mutagenicity of acrylamide and its analogues in Salmonella typhimurium. Mutat. Res. 158, 129133.[ISI][Medline]
Hayashi, N., Hasegawa, K., Komine, A., Tanaka, Y., McLachlan, J. A., Barrett, J. C., and Tsutsui, T. (1996). Estrogen-induced cell transformation and DNA adduct formation in cultured Syrian hamster embryo cells. Mol. Carcinog. 16, 149156.[ISI][Medline]
Isfort, R. J., Cody, D. B., Doersen, C. J., Kerckaert, G. A., and LeBoeuf, R. F. (1994). Alterations in cellular differentiation, mitogenesis, cytoskeleton, and growth characteristics during Syrian hamster embryo cell multi-step in vitro transformation. Int. J. Cancer 59, 114125.[ISI][Medline]
Johnson, K. A., Gorzinski, S. J., Bodner, K. M., Campbell, R. A., Wolf, C. H., Friedman, M. A., and Mast, R. W. (1986). Chronic toxicity and oncogenicity study on acrylamide incorporated in the drinking water of Fisher 344 rats. Toxicol. Appl. Pharmacol. 85, 154168.[ISI][Medline]
Kaster, J. K., Kamendulis, L. M., Friedman, M. A., and Klaunig, J. E. (1997). Syrian hamster embryo (SHE) cell transformation by acrylamide and hormones. Toxicologist 18, 56.
Kerckaert, G. A., Isfort, R. J., Carr, G. J., Aardema, M. J., and LeBoeuf, R. A. (1996). A comprehensive protocol for conducting the Syrian hamster embryo cell transformation assay at pH 6.70. Mutat. Res. 356, 6584.[ISI][Medline]
Khan, M. A., Davis, C. A., Foley, G. L, Friedman, M. A., and Hansen, L. G. (1999). Changes in thyroid gland morphology after acute acrylamide exposure. Toxicol. Sci. 47, 151157.[Abstract]
Korach, K. S., and McLachlan, J. A. (1985). The role of the estrogen receptor in diethylstilbestrol toxicity. Arch. Toxicol. 58 (Suppl.), 3342.[ISI][Medline]
Liaw, L., and Schwartz, S. M. (1993). Microtubule disruption stimulates DNA synthesis in bovine endothelial cells and potentiates cellular response to basic fibroblast growth factor. Am. J. Pathol. 143, 937948.[Abstract]
Lowry, O. H., Rosebrough, N. J., Farr, A. L., and Randall, R. J. (1951). Protein measurement with the Folin phenol reagent. J. Biol. 64, 95102.
McLachlan, J. A., Wong, A., Degan, G. H., and Barrett, J. C. (1982). Morphological and neoplastic transformation of Syrian hamster embryo fibroblasts by diethylstilbestrol and its analogs. Cancer Res. 42, 30403045.[Abstract]
Metzler, M., and Schiffmann, D. (1991). Structural requirements for the in vitro transformation of Syrian hamster embryo cells by stilbene estrogens and triphenylethylene-type antiestrogens. Am. J. Clin. Oncol. 14(Suppl.), S3035.[ISI][Medline]
Miller, M. J., Carter, D. E., and Sipes, I. G. (1982). Pharmacokinetics of acrylamide in Fisher-344 rats. Toxicol. Appl. Pharmacol. 63, 3644.[ISI][Medline]
Moore, M., Amtower, A., Doerr, C., Brock, K. H., and Dearfield, K. L. (1987). Mutagenicity and clastogenicity of acrylamide in L5178Y mouse lymphoma cells. Environ. Mutagen. 9, 261267.[ISI][Medline]
Pienta, K. J., and Coffey, D. S. (1992). Nuclear-cytoskeletal interactions: Evidence for physical connections between the nucleus and cell periphery and their alteration by transformation. J. Cell Biochem. 49, 357365.[ISI][Medline]
Schulze-Osthoff, K., Los, M., and Baeuerle, P. A. (1995). Redox signaling by transcription factors NF-B and AP-1 in lymphocytes. Biochem. Pharmacol. 50, 735741.[ISI][Medline]
Segerbäck, D., Calleman, C. J., Schroeder, J. L., Costa, L. G., and Faustman, E. M. (1995). Formation of N-7-(2-carbamonyl-2-hydroxyethyl)guanine in DNA of the mouse and the rat following intraperitoneal administration of [14C]acrylamide. Carcinogenesis 16, 11611165.[Abstract]
Shiraishi, Y. (1978). Chromosome aberrations induced by monomeric acrylamide in bone marrow and germ cells of mice. Mutat. Res. 57, 313324.[ISI][Medline]
Sickles, D. W., Brady, S. T., Testino, A., Friedman, M. A., and Wrenn, R. W. (1996). Direct effect of the neurotoxicant acrylamide on kinesin-based microtubule motility. J. Neurosci. Res. 46, 717.[ISI][Medline]
Solomon, J. J., Fedyk, J., Mukai, F., and Segal, A. (1985). Direct alkylation of 2`-deoxynucleosides and DNA following in vitro reaction with acrylamide. Cancer Res. 45, 34653470.[Abstract]
Srivastava, S. P., Sabri, M. I., Agrawal, A. K., and Seth, P. K. (1986). Effect of single and repeated doses of acrylamide and bis-acrylamide on glutathione S-transferase and dopamine receptors in rat brain. Brain Res. 371, 319323.[ISI][Medline]
Stack, D. E., Byun, J., Gross, M. L., Rogan, E. G., and Cavalieri, E. L. (1996). Molecular characteristics of catechol estrogen quinines in reactions with deoxyribonucleosides. Chem. Res. Toxicol. 9, 851859.[ISI][Medline]
Sumner, S. C., Fennell, T. R., Moore, T. A., Chanas, B., Gonzalez, F., and Ghanayem, B. I. (1999). Role of cytochrome P450 2E1 in the metabolism of acrylamide and acrylonitrile in mice. Chem. Res. Toxicol. 12, 11101116.[ISI][Medline]
Tareke, E., Rydberg, P., Karlsson, P., Eriksson, S., and Tornqvist, M. (2000). Acrylamide: A cooking carcinogen? Chem. Res. Toxicol. 13, 517522.[ISI][Medline]
Trosko, J. E., Chang, C. C., Upham, B., and Wilson, M. (1998). Epigenetic toxicology as toxicant-induced changes in intracellular signaling leading to altered gap-junctional intercellular communication. Toxicol. Lett. 102103, 7178.
Tsuda, H., Shimizu, C. S., Taketomi, M. K., Hasegawa, M. M., Hamada, A., Kawata, K. M., and Inui, N. (1993). Acrylamide: Induction of DNA damage, chromosomal aberrations, and cell transformation without gene mutations. Mutagenesis 8, 2329.[Abstract]
Tsutsui, T., and Barrett, J. C. (1997). Neoplastic transformation of cultured mammalian cells by estrogens and estrogen-like chemicals. Environ. Health Perspect. 105(Suppl.), 619624.[ISI][Medline]
Tsutsui, T., Hayashi, N., Maizumi, H., Huff, J., and Barrett, J. C. (1997). Benzene-, catechol-, hydroquinone-, and phenol-induced cell transformation, gene mutations, chromosome aberrations, aneuploidy, sister chromatid exchanges and unscheduled DNA synthesis in Syrian hamster embryo cells. Mutat. Res. 373, 113123.[ISI][Medline]
Tsutsui, T., Maizumi, H., McLachlan, J. A., and Barrett, J. C. (1983). Aneuploidy induction and cell transformation by diethylstilbestrol: A possible chromosomal mechanism in carcinogenesis. Cancer Res. 43, 38143821.[ISI][Medline]
Tsutsui, T., Suzuki, N., Fukuda, S., Sato, M., Maizumi, H., McLachlan, J. A., and Barrett, J. C. (1987). 17ß-Estradiol-induced cell transformation and aneuploidy of Syrian hamster embryo cells in culture. Carcinogenesis 8, 17151719.[Abstract]
Yamasaki, H., Ashby, J., Bignami, M., Jongen, W., Linnainmaa, K., Newbold, R. F., Nguyen-Ba, G., Parodi, S., Rivedal, E., Schiffmann, D., Simons, J. W., and Vasseur, P. (1996). Nongenotoxic carcinogens: Development of detection methods based on mechanisms. A European project. Mutat. Res. 353, 4763.[ISI][Medline]