Laboratory of Molecular Immunology, Guthrie Research Institute, Guthrie Medical Center, Sayre, Pennsylvania 18840
![]() |
ABSTRACT |
---|
![]() ![]() ![]() ![]() ![]() ![]() ![]() |
---|
Both
hyaluronidase and transforming growth factor (TGF)-1 play a
significant role in the development of prostate cancer. In this study,
the regulation of tumor necrosis factor (TNF)-mediated cell death by
hyaluronidase and TGF-
1 was investigated. Preexposure of L929
fibroblasts, prostate LNCaP cells, and epithelial Mv 1 Lu cells to
hyaluronidase for a minimum of 12 h resulted in significant enhancement
of cell death by TNF. Phosphorylation of p42 and p44 mitogen-activated
protein (MAP) kinases was found by stimulation of L929 cells with
hyaluronidase for 30 min, indicating that the Raf/MAP
kinase-extracellular signal-regulating protein kinase (MEK)/MAP kinase pathway was activated. However, blocking the activation of upstream MAP kinase kinase (MEK 1 and 2 kinase) by
PD-98059 failed to inhibit the hyaluronidase-enhanced TNF killing of
cells, suggesting that hyaluronidase-mediated degradation of extracellular matrix and membrane components may elicit multiple signaling pathways. As a potent stimulator of extracellular matrix protein synthesis, TGF-
1 blocked the hyaluronidase-enhanced death of
L929 and LNCaP cells mediated by TNF. TGF-
1 activated
protein-tyrosine kinases in L929 cells, in which the tyrosine kinase
inhibitors lavendustin A and tyrphostin blocked the activation as well
as the TGF-
1 inhibition of hyaluronidase effects. Functional
antagonism was also observed between hyaluronidase and TGF-
1 in cell
growth regulation. For example, TGF-
1-mediated suppression of
epithelial Mv 1 Lu cell growth was abolished by hyaluronidase. Overall,
it is demonstrated in this study that hyaluronidase reciprocally antagonized TGF-
1 in the modulation of cell proliferation and TNF-mediated death.
transforming growth factor-1; tumor necrosis factor; apoptosis; L929 cells; LNCaP cells
![]() |
INTRODUCTION |
---|
![]() ![]() ![]() ![]() ![]() ![]() ![]() |
---|
AS A MATRIX-DEGRADING ENZYME, hyaluronidase participates in cancer progression, invasion, and angiogenesis. Various cancer cells, such as Wilms' tumor, produce hyaluronidase (22, 29). Elevation of hyaluronidase levels is associated with prostate cancer progression (18). Expression of hyaluronidase by tumor cells induces angiogenesis in vivo (17). Notably, the growth of murine lung carcinoma and melanoma is influenced by Hyal-1, a locus determining hyaluronidase levels and polymorphism (11).
As opposed to the function of hyaluronidase, transforming growth factor
(TGF)- is a potent stimulator of extracellular matrix protein
synthesis (25). Moreover, TGF-
increases tumorigenicity in vivo by
suppressing the local immune system (13, 15). Overexpression of TGF-
is frequently associated with the development of benign prostatic
hyperplasia to malignant prostate cancer (27, 28) and breast cancer
progression (1, 33).
In this study, TGF-1 was found to reciprocally counteract
hyaluronidase function in the regulation of cell proliferation and
tumor necrosis factor (TNF)-mediated cell death. Both in vitro and in
vivo studies have shown that destruction of extracellular matrix by
hyaluronidase increases cancer cell susceptibility to chemotherapeutic
drugs (2, 10, 16, 24, 26). As determined in this study, pretreatment of
L929 fibrosarcoma (6, 7), prostate LNCaP (31) and lung epithelial Mv 1 Lu (23) cells with hyaluronidase for at least 12 h, followed by
exposure to TNF, resulted in increased cell death.
TGF-1 protects L929 cells from TNF killing (6). Interestingly,
TGF-
1 inhibited the hyaluronidase-mediated enhancement of TNF
killing. Conversely, hyaluronidase counteracted TGF-
1-mediated growth inhibition of epithelial Mv 1 Lu cells (23). How TGF-
1 counteracted hyaluronidase induction of TNF sensitivity in L929 cells
was investigated.
![]() |
MATERIALS AND METHODS |
---|
![]() ![]() ![]() ![]() ![]() ![]() ![]() |
---|
Cell lines. TNF-sensitive L929 cells were cultured in 10% newborn calf serum-RPMI 1640 medium as previously described (6, 7). Mink lung epithelial Mv 1 Lu cells (23) and human prostate cancer LNCaP cells (31) were cultured according to the instructions of the American Type Culture Collection (Rockville, MD).
TNF cytotoxicity assays.
TNF cytotoxicity assays were performed as previously described
(5-7). Briefly, 100-µl aliquots of L929 cells (2.5 × 105 cells/ml) were dispensed onto
96-well microtiter plates (Corning, Corning, NY), cultured for 24 h,
treated with bovine testicular hyaluronidase (0-200 U/ml; Sigma)
for 12-24 h, and exposed to recombinant TNF- (500-4,000
U/ml; Genzyme, Boston, MA) for 16-24 h. To determine the extent of
death, the cells were fixed and stained with crystal violet (2% in
50% methanol) and analyzed in an automatic microtiter plate reader for
optical density (OD) at 560 nm (SLT Labinstruments,
Research Triangle Park, NC). Compared with each hyaluronidase-treated
or untreated cell group, the extent of cell death in the corresponding
TNF-treated cell group (hyaluronidase-treated or untreated cells) was
calculated as follows: %Cell death = [(OD from control cells
OD from TNF-treated cells) / OD from control cells] × 100. The extent of hyaluronidase-mediated enhancement of TNF
cytotoxicity was also calculated: %Enhancement = [(%TNF killing
of hyaluronidase-stimulated cells / %TNF killing of control cells)
1] × 100 (5-7). Unless otherwise indicated,
data are presented as means ± SD
(n = 8). As indicated, the extent of
cell death was also confirmed by using a
3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS tetrazolium) proliferation assay kit (Promega, Madison, WI). Conversion of the MTS tetrazolium into a soluble formazan by viable cells was measured as 490-nm OD (4). Similar experiments were performed
using Mv 1 Lu and LNCaP cells.
Functional antagonism of TGF-1.
TGF-
1 regulation of hyaluronidase-mediated enhancement of L929 cell
death by TNF was examined. L929 cells were pretreated with
hyaluronidase in the presence or absence of purified human platelet
TGF-
1 (0.25-2 ng/ml; Collaborative Research, Bedford, MA) for
16-24 h, followed by removal of the culture supernatants and
exposure to TNF for 16-24 h. Similarly, the
hyaluronidase-pretreated L929 cells (16-24 h) were exposed to
TGF-
1 for 1-7 h, followed by removal of culture supernatants
and incubation with TNF for 16-24 h, or the
hyaluronidase-pretreated cells were exposed simultaneously to TGF-
1
and/or TNF for 16-24 h. Also, TGF-
1 (0.25-2 ng/ml; in 50 µl of RPMI 1640 medium containing 2% albumin) was precoated onto 96-well microtiter plates for 9 h in a humidified 37°C
incubator (nondry coating with lids on), after which the plates were
washed twice with phosphate-buffered saline (PBS) and L929 cells were seeded. These cells were cultured overnight, treated with hyaluronidase for 24 h, and subsequently exposed to TNF for 16-24 h.
Western blotting. To examine whether hyaluronidase activated the Raf/MEK/MAP kinase pathway, L929 cells in petri dishes were treated with hyaluronidase (100 U/ml) for 0, 0.5, 1, 2, or 4 h, followed by washing with cold PBS and lysis of the cells with a lysis buffer (6). Western blotting was performed as described (8). Briefly, 10 µg of the cell lysates were subjected to reducing sodium dodecyl sulfate-polyacrylamide gel electrophoresis, electroblotting of the separated proteins onto a Zeta-probe nylon membrane (Bio-Rad Laboratories, Hercules, CA), and probing with specific polyclonal immunoglobulin G antibodies against a synthetic phosphopeptide of p42 and p44 MAP kinases (New England BioLab, Beverly, MA).
Hyaluronidase blocking of TGF-1-mediated growth
inhibition.
TGF-
1 is known to restrict the proliferation of Mv 1 Lu cells (23).
To examine the functional antagonism between TGF-
1 and
hyaluronidase, Mv 1 Lu cells were treated with TGF-
1 in the presence
or absence of hyaluronidase for 24 and 48 h. The extent of cell
proliferation was examined by both crystal violet staining and the MTS
assay.
![]() |
RESULTS |
---|
![]() ![]() ![]() ![]() ![]() ![]() ![]() |
---|
Hyaluronidase enhancement of TNF- and serum deprivation-mediated apoptosis. Pretreatment of L929 cells with hyaluronidase for 16 h at 37°C, followed by removal of hyaluronidase and exposure to TNF (1,000 U/ml) for 24 h, resulted in increased cell death or apoptosis (Fig. 1). These results were observed by staining the cells with crystal violet, and comparable results were obtained using the MTS proliferation assay (data not shown). The enhanced cell death also occurred when the hyaluronidase-pretreated L929 cells were exposed to TNF with the continuous presence of hyaluronidase. Hyaluronidase increased L929 cell growth by ~5-10% in 16 h (Fig. 1). Time course studies demonstrated that development of the enhanced TNF killing required pretreatment of L929 cells with hyaluronidase for a minimum of 12 h (data not shown). TNF-mediated apoptotic cell death was verified by analysis of internucleosomal DNA fragmentation. Compared with control cells, the hyaluronidase-pretreated cells, when challenged with TNF for 6 h, had increased DNA fragmentation (Fig. 1). A higher concentration of TNF (4,000 U/ml) was used in this short-term assay.
|
|
|
Hyaluronidase activation of the Raf/MEK/MAP kinase pathway in L929 cells. Hyaluronidase-mediated activation of p42 and p44 MAP kinases was examined. Exposure of L929 cells to hyaluronidase for 30 min resulted in activation of p42 and p44 MAP kinases of the Raf/MEK/MAP kinase pathway, as observed in the Western blotting using the specific antibodies against a synthetic tyrosine-phosphopeptide of p42 and p44 MAP kinases (Fig. 4A). Nonetheless, blocking the activation of MEK 1 and 2 kinases (upstream activators of p42 and p44 MAP kinases) by the specific inhibitor PD-98059 failed to abolish the hyaluronidase enhancement of TNF killing. Indeed, PD-98059 alone inhibited TNF killing of L929 cells, whereas hyaluronidase reversed this inhibitory effect and restored the sensitivity of L929 cells to TNF (Fig. 4B). During the 48-h culture period, PD-98059 significantly inhibited L929 cell growth, whereas hyaluronidase reversed the growth inhibitory effect of PD-98059 (Fig. 4C).
|
TGF-1 inhibition of hyaluronidase enhancement of TNF
killing.
TGF-
1 was found to inhibit hyaluronidase-mediated enhancement of TNF
killing. When L929 cells were pretreated with hyaluronidase for 22 h,
followed by exposure to TGF-
1 for 1.5 h and subsequent treatment
with TNF for 16-24 h, the hyaluronidase-enhanced TNF killing was
blocked by TGF-
1 (Fig.
5A).
Similar results were obtained by exposure of the
hyaluronidase-pretreated L929 cells to TGF-
1 for 2-7 h (data
not shown). Exposure of the hyaluronidase-pretreated L929 cells to both
TNF and TGF-
1 for 16-24 h also resulted in abrogation of the
effects of hyaluronidase. Growth of L929 cells overnight in 96-well
plates that had been precoated with TGF-
1, followed by treatment
with hyaluronidase for 24 h, also resulted in blocking of the
hyaluronidase enhancement of TNF killing by TGF-
1 (Fig.
5B). TGF-
1 also inhibited
TNF-mediated nuclear DNA fragmentation in both control and
hyaluronidase-pretreated cells (Fig.
5C).
|
|
Blocking of TGF-1 effects by protein-tyrosine kinase
inhibitors.
Previously, I have shown that protein-tyrosine kinase inhibitors, such
as lavendustin A and tyrphostin, inhibit TGF-
1 function in
protecting L929 cells against TNF-mediated cell death and that TGF-
1
stimulates protein-tyrosine phosphorylation in L929 cells (6). In this
study, both lavendustin A and tyrphostin blocked the counteractive
effect of TGF-
1 against hyaluronidase. When L929 cells were
pretreated with hyaluronidase for 16-24 h and subsequently exposed
to TGF-
1 in the presence of lavendustin A or tyrphostin for 7 h, the
TGF-
1 inhibition of the hyaluronidase-increased TNF killing was
abolished (Fig. 7). In
contrast, H-7, a PKC inhibitor, was less effective in blocking the
TGF-
1 effect (Fig. 7). Both lavendustin A and tyrphostin could not
abolish the effect of hyaluronidase in increasing TNF sensitivity in
L929 cells (data not shown).
|
Hyaluronidase reversal of TGF-1-mediated suppression
of Mv 1 Lu cell growth.
Finally, the functional antagonism between hyaluronidase and TGF-
1
was observed in the regulation of cell growth. In agreement with other
observations (23), treatment of Mv 1 Lu cells with TGF-
1 resulted in
inhibition of cell proliferation (Fig.
8A). This growth inhibitory effect of TGF-
1 was reversed by hyaluronidase (Fig. 8A). TGF-
1 inhibited Mv 1 Lu cell growth but failed to induce apoptosis in these cells, as
determined by nuclear DNA fragmentation analysis (Fig.
8B).
|
![]() |
DISCUSSION |
---|
![]() ![]() ![]() ![]() ![]() ![]() ![]() |
---|
In this study, functional antagonism between hyaluronidase and TGF-1
was observed in the modulation of cell proliferation and TNF-mediated
cell death. As an extracellular matrix degrading enzyme, hyaluronidase
increased TNF-mediated killing of L929 fibroblasts, prostate LNCaP
cells, and epithelial Mv 1 Lu cells. In contrast, as a potent
stimulator of extracellular matrix protein synthesis, TGF-
1 blocked
the hyaluronidase-mediated enhancement of TNF killing in these cells.
Conceivably, one of the mechanisms by which TGF-
1 blocked the
hyaluronidase effects is TGF-
1 restoration of the damaged
extracellular matrix by hyaluronidase.
The physical integrity of extracellular matrix is important in protecting cancer cells from attack by anticancer drugs and the immune system. Thus treatment of cancer cells with hyaluronidase, either in vivo or in vitro, increases their susceptibility to anticancer drugs (2, 10, 16, 24, 26). However, these observations are in contrast to my previous report that, when L929 cells were pretreated with hyaluronidase for 12-24 h, the cells resisted killing by TNF and anti-Fas antibodies in the presence of anticancer drugs such as actinomycin D, doxorubicin, daunorubicin, and cycloheximide (7). In this study, however, pretreatment of L929 and LNCaP cells with hyaluronidase for 12-24 h resulted in increased TNF sensitivity without the presence of these anticancer drugs. These observations indicate that hyaluronidase-mediated de novo protein synthesis is essential for conferring TNF susceptibility in these cells. Indeed, by metabolic labeling we have demonstrated seven protein species induced by hyaluronidase in L929 cells (N.-S. Chang, N. Joki, J. Mattison, E. Chu, and M. Ou, unpublished observations). Conceivably, one of these proteins is capable of enhancing TNF killing in L929 cells.
Additionally, a likely scenario that accounts for the increased TNF sensitivity in L929 and LNCaP cells is due to the release of growth factors from the extracellular matrix on digestion with hyaluronidase. The extracellular matrix is an excellent reservoir for growth factors such as fibroblast growth factor. Presumably, these growth factors enhance L929 cell proliferation and increase their TNF susceptibility, since in most cases TNF targets proliferating cells. Thus the role of growth factors from the extracellular matrix in conferring TNF susceptibility in certain cancer cells remains to be established.
Although degradation of extracellular matrix hyaluronic acid and
chondroitin sulfate occurred in hyaluronidase-treated cells, exogenous
glycosaminoglycans, including hyaluronic acid, chondroitin sulfate,
dermatan sulfate, heparan sulfate and heparin, failed to block the
hyaluronidase effects (data not shown). Notably, as a stabilizer of
extracellular matrix, the hyaluronic acid-binding protein
inter--inhibitor (9) blocks hyaluronidase induction of TNF
sensitivity in L929 cells (Chang et al., unpublished observations). This observation indicates that extracellular matrix proteins participate in conferring TNF resistance in L929 and probably other
cells.
Previously, I have shown that hyaluronidase fails to alter the expression of TNF receptors and the receptor binding affinity for TNF in L929 cells (7). Furthermore, hyaluronidase-pretreated L929 cells, with subsequent exposure to TNF and/or actinomycin D, exhibit no significant changes in the expression of apoptosis regulatory proteins (7), such as Bcl-2 (19), Bcl-x (3), Ich-1 (32) and the RNA-binding protein TIAR (30). Thus these proteins are not involved in the hyaluronidase-mediated enhancement of TNF killing in L929 cells.
Not all the cancer cells can be induced by hyaluronidase to increase their TNF susceptibility. For example, TNF-resistant prostate DU 145, ovarian Me-180, and monkey kidney COS-7 cells were refractory to hyaluronidase induction of TNF sensitivity. The underlying mechanism is unknown. However, the differences in the responsiveness of prostate LNCaP and DU 145 cells to hyaluronidase induction of TNF sensitivity suggest that cellular genetic variations and mutations, culture conditions, and cell origins contribute to their differential responsiveness to TNF and/or hyaluronidase.
The Raf/MEK/MAP kinase pathway was activated when L929 cells were treated with hyaluronidase for 30 min, as evidenced by the phosphorylation of p42 and p44 MAP kinases. However, inhibition of the upstream MEK 1 and 2 kinase activation by PD-98059 failed to abolish the hyaluronidase effects. These observations suggest that multiple signaling pathways may be transduced into cells by digestion of the cells and surrounding extracellular matrix with hyaluronidase.
Most interestingly, PD-98059 inhibited L929 cell proliferation and rendered these cells TNF resistant. These inhibitory effects were reversed by hyaluronidase. Thus this observation further supports the notion that additional signaling pathways are elicited by hyaluronidase. In addition to PD-98059, I have examined a variety of protein tyrosine and serine/threonine kinase inhibitors in blocking the hyaluronidase effects. These inhibitors included lavendustin A, tyrphostin, herbimycin A, H-7, and G-490 (a selective inhibitor of JAK-2 kinase). Nonetheless, these inhibitors were not able to block the hyaluronidase effects. Thus hyaluronidase-elicited signaling transduction remains to be established.
Hyaluronidase partially enhanced serum growth factor-mediated proliferation of L929 cells, whereas on withdrawal of serum the hyaluronidase-pretreated L929 cells had an increased retardation of growth. The continuous presence of serum supports the cells to enter rounds of cell cycles, and hyaluronidase enhances the cell cycle progression, probably by inducing de novo protein synthesis. On withdrawal of serum growth factors, the hyaluronidase-pretreated L929 cells probably enter growth arrest in the G1 phase faster than untreated starved cells. These hyaluronidase-pretreated L929 cells will undergo apoptosis as long as the serum growth factors are continuously absent. Although it is not yet tested, it is reasonable to postulate that activation of caspase proteins, the cell death proteases, is enhanced in hyaluronidase-pretreated L929 cells, compared with control cells.
How hyaluronidase supports prostate cancer progression is unknown. On the basis of our data from L929 and other cells, hyaluronidase stimulates cancer cell growth, and these proliferating cells are the targets for anticancer drugs, such as actinomycin D, doxorubicin, and daunorubicin, and for TNF. However, development of drug resistance in cancer cells is not only dependent on the expression of the multiple drug resistance gene but is also related to hyaluronidase secretion. Although cotreatment of cancer cells with hyaluronidase and anticancer drugs increases the drug-mediated killing (2, 10, 16, 24, 26), my unpublished observations showed that, when L929 and LNCaP cells were pretreated with hyaluronidase for 24 h, these cells became resistant to killing by actinomycin D, doxorubicin, and daunorubicin. Thus hyaluronidase-secreting cancer cells may indeed resist killing by anticancer drugs, thus allowing their progression.
TGF-1 restoration of the hyaluronidase-destroyed extracellular
matrix may contribute in part to the inhibition of hyaluronidase effects. As a potent builder of extracellular matrix, TGF-
1
abrogated the hyaluronidase enhancement of TNF killing of L929 and
LNCaP cells. Previously, I reported that TGF-
1 rapidly increases
protein tyrosine phosphorylation in L929 cells, and that these cellular tyrosine phosphorylated proteins interrupt the TNF killing pathway (6).
Accordingly, treatment of L929 cells with TGF-
1 in the presence of
tyrosine kinase inhibitors such as lavendustin A and tyrphostin
abolished the TGF-
1 antagonism of hyaluronidase.
Functional antagonism also demonstrated that hyaluronidase blocked
TGF-1-mediated growth inhibition of Mv 1 Lu cells. Similar results
were also observed in COS-7 and Me-180 cells (data not shown). Although
the underlying mechanism remains to be established, my observations
raise an intriguing question regarding how overproduction of both
hyaluronidase and TGF-
contributes to the progression and metastasis
of prostate cancer. Conceivably, a balanced production of hyaluronidase
and TGF-
1 by prostate cancer is important for their development.
Overall, in this study, the in vitro functional antagonism between
hyaluronidase and TGF-1 is demonstrated. Whether hyaluronidase and
TGF-
1 act synergistically or antagonistically in vivo remains to be
established.
![]() |
ACKNOWLEDGEMENTS |
---|
I thank Dr. Lynda Bonewald (University of Texas Health Science Center, San Antonio, TX) for carefully reviewing the manuscript. The technical assistance of Nicole Joki and Jeffery Mattison is appreciated.
![]() |
FOOTNOTES |
---|
This research was supported by the Wendy Will Case Cancer Fund, National Cancer Institute Grants R01-CA61879 and R55-CA64423, and the Guthrie Foundation for Education and Research.
Received 27 June 1997; accepted in final form 25 August 1997.
![]() |
REFERENCES |
---|
![]() ![]() ![]() ![]() ![]() ![]() ![]() |
---|
1.
Arteaga, C. L., T. C. Dugger, A. R. Winnier, and J. T. Forbes. Evidence for a positive role
of transforming growth factor-beta in human breast cancer cell
tumorigenesis. J. Cell Biochem. 17G,
Suppl.: 187-193,
1993.
2.
Beckenlehner, K.,
S. Bannke,
T. Spruss,
G. Bernhardt,
H. Schonenberg,
and
W. Schiess.
Hyaluronidase enhances the activity of adriamycin in breast cancer models in vitro and in vivo.
J. Cancer Res. Clin. Oncol.
118:
591-596,
1992[Medline].
3.
Boise, L. H.,
M. Gonzalez-Garcia,
C. E. Postema,
L. Ding,
T. Lindsten,
L. A. Turka,
X. Mao,
G. Nunez,
and
C. B. Thompson.
Bcl-x, a bcl-2-related gene that functions as a dominant regulator of apoptotic cell death.
Cell
74:
597-608,
1993[Medline].
4.
Buttke, T. M.,
J. A. McCubrey,
and
T. C. Owen.
Use of an aqueous soluble tetrazolium/formazan assay to measure viability and proliferation of lymphokine-dependent cell lines.
J. Immunol. Methods
157:
233-240,
1993[Medline].
5.
Cao, H.,
J. Mattison,
Y. Zhao,
N. Joki,
M. Grasso,
and
N.-S. Chang.
Regulation of tumor necrosis factor- and Fas-mediated apoptotic cell death by a novel cDNA, TR2L.
Biochem. Biophys. Res. Commun.
227:
266-272,
1996[Medline].
6.
Chang, N.-S.
TGF-1 induction of novel extracellular proteins that trigger resistance to TNF cytotoxicity in murine L929 fibroblasts.
J. Biol. Chem.
270:
7765-7772,
1995
7.
Chang, N.-S.
Hyaluronidase induces murine L929 fibrosarcoma cells resistant to tumor necrosis factor and Fas cytotoxicity in the presence of actinomycin D.
Cell Biochem. Biophys.
27:
109-132,
1996.
8.
Chang, N.-S.,
R. W. Leu,
J. A. Rummage,
J. K. Anderson,
and
J. E. Mole.
Regulation of complement functional efficiency by plasma histidine-rich glycoprotein.
Blood
79:
2973-2980,
1992[Abstract].
9.
Chen, L.,
S. J. Mao,
L. R. McLean,
R. W. Powers,
and
W. J. Larsen.
Proteins of the inter-alpha-trypsin inhibitor family stabilize the cumulus extracellular matrix through their direct binding with hyaluronic acid.
J. Biol. Chem.
269:
28282-28287,
1994
10.
Croix, B. S.,
J. W. Rak,
S. Kapitain,
C. Sheehan,
C. H. Graham,
and
R. S. Kerbel.
Reversal by hyaluronidase of adhesion-dependent multicellular drug resistance in mammary carcinoma cells.
J. Natl. Cancer Inst.
88:
1285-1296,
1996
11.
De Maeyer, E.,
and
J. De Maeyer-Guignard.
The growth rate of two transplantable murine tumors, 3LL lung carcinoma and B16F10 melanoma, is influenced by Hyal-1, a locus determining hyaluronidase levels and polymorphism.
Int. J. Cancer
51:
657-660,
1992[Medline].
12.
Gazit, A.,
P. Yaish,
C. Gilon,
and
A. Levitzki.
Tyrphostins I: synthesis and biological activity of protein tyrosine kinase inhibitors.
J. Med. Chem.
32:
2344-2352,
1989[Medline].
13.
Gray, J. D.,
M. Hirokawa,
and
D. A. Horwitz.
The role of transforming growth factor beta in the generation of suppression: an interaction between CD8+ T and NK cells.
J. Exp. Med.
180:
1937-1942,
1994[Abstract].
14.
Kawamoto, S.,
and
H. Hidaka.
1-(5-Isoquinolinesulfonyl)-2-methylpiperazine (H-7) is a selective inhibitor of protein kinase C in rabbit platelets.
Biochem. Biophys. Res. Commun.
125:
258-264,
1984[Medline].
15.
Kehrl, J. H.,
L. M. Wakefield,
A. B. Roberts,
S. Jakowlew,
M. Alvarez-Mon,
R. Derynck,
M. B. Sporn,
and
A. S. Fauci.
Production of transforming growth factor beta by human T lymphocytes and its potential role in the regulation of T cell growth.
J. Exp. Med.
163:
1037-1050,
1986[Abstract].
16.
Klocker, J.,
H. Sabitzer,
W. Raunik,
S. Wieser,
and
J. Schumer.
Combined application of cisplatin, vindesine, hyaluronidase and radiation for treatment of advanced squamous cell carcinoma of the head and neck.
Am. J. Clin. Oncol.
18:
425-428,
1995[Medline].
17.
Liu, D.,
E. Pearlman,
E. Diaconu,
K. Guo,
H. Mori,
T. Haqqi,
S. Markowitz,
J. Willson,
and
M. S. Sy.
Expression of hyaluronidase by tumor cells induces angiogenesis in vivo.
Proc. Natl. Acad. Sci. USA
93:
7832-7837,
1996
18.
Lokeshwar, V. B.,
B. L. Lokeshwar,
H. T. Pham,
and
N. L. Block.
Association of elevated levels of hyaluronidase, a matrix-degrading enzyme, with prostate cancer progression.
Cancer Res.
56:
651-657,
1996[Abstract].
19.
Nunez, G.,
R. Merino,
D. Grillot,
and
M. Gonzalez-Garcia.
Bcl-2 and Bcl-x: regulatory switches for lymphoid death and survival.
Immunol. Today
15:
582-588,
1994[Medline].
20.
Onoda, T.,
H. Iinuma,
Y. Sasaki,
M. Hamada,
K. Isshiki,
H. Naganawa,
T. Takeucmi,
K. Tatsuta,
and
K. Umezawa.
Isolation of a novel tyrosine kinase inhibitor, lavendustin A, from Streptomyces griseolavendus.
J. Nat. Prod.
52:
1252-1257,
1989[Medline].
21.
Pang, L.,
T. Sawada,
S. J. Decker,
and
A. R. Saltiel.
Inhibition of MAP kinase kinase blocks the differentiation of PC-12 cells induced by nerve growth factor.
J. Biol. Chem.
270:
13585-13588,
1995
22.
Pham, H. T.,
N. L. Block,
and
V. B. Lokeshwar.
Tumor-derived hyaluronidase: a diagnostic urine marker for high-grade bladder cancer.
Cancer Res.
57:
778-783,
1997[Abstract].
23.
Satterwhite, D. J.,
M. E. Aakre,
A. E. Gorska,
and
H. L. Moses.
Inhibition of cell growth by TGF beta 1 is associated with inhibition of B-myb and cyclin A in both BALB/MK and Mv1Lu cells.
Cell Growth Differ.
5:
789-799,
1994[Abstract].
24.
Smith, K. J.,
H. G. Skelton,
G. Turiansky,
and
K. F. Wagner.
Hyaluronidase enhances the therapeutic effect of vinblastine in intralesional treatment of Kaposi's sarcoma.
J. Am. Acad. Dermatol.
36:
239-242,
1997[Medline].
25.
Sporn, M. B.,
and
A. B. Roberts.
The transforming growth factor-betas: past, present, and future.
Ann. NY Acad. Sci.
593:
1-6,
1990[Medline].
26.
Spruss, T.,
G. Bernhardt,
H. Schonenberger,
and
W. Schiess.
Hyaluronidase significantly enhances the efficacy of regional vinblastine chemotherapy of malignant melanoma.
J. Cancer Res. Clin. Oncol.
121:
193-202,
1995[Medline].
27.
Steiner, M. S.,
and
E. R. Barrack.
Transforming growth factor-beta 1 overproduction in prostate cancer: effects on growth in vivo and in vitro.
Mol. Endocrinol.
6:
15-25,
1992[Abstract].
28.
Steiner, M. S.,
Z. Z. Zhou,
D. C. Tonb,
and
E. R. Barrack.
Expression of transforming growth factor-beta 1 in prostate cancer.
Endocrinology
135:
2240-2247,
1994[Abstract].
29.
Stern, M.,
M. T. Longaker,
N. S. Adzick,
M. R. Harrison,
and
R. Stern.
Hyaluronidase levels in urine from Wilms' tumor patients.
J. Natl. Cancer Inst.
83:
1569-1574,
1991[Abstract].
30.
Taupin, J. L.,
Q. Tian,
N. Kedersha,
M. Robertson,
and
P. Anderson.
The RNA-binding protein TIAR is translocated from the nucleus to the cytoplasm during Fas-mediated apoptotic cell death.
Proc. Natl. Acad. Sci. USA
92:
1629-1633,
1995[Abstract].
31.
Veldscholte, J.,
C. A. Berrevoets,
and
E. Mulder.
Studies on the human prostatic cancer cell line LNCaP.
J. Steroid Biochem. Mol. Biol.
49:
341-346,
1994[Medline].
32.
Wang, L.,
M. Miura,
L. Bergeron,
H. Zhu,
and
J. Yuan.
Ich-1, an Ice/ced-3-related gene, encodes both positive and negative regulators of programmed cell death.
Cell
78:
739-750,
1994[Medline].
33.
Welch, D. R.,
A. Fabra,
and
M. Nakajima.
Transforming growth factor beta stimulates mammary adenocarcinoma cell invasion and metastatic potential.
Proc. Natl. Acad. Sci. USA
87:
7678-7682,
1990[Abstract].