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Endocrinology |
-Induced Matrix Proteolytic Enzyme Production and Basement Membrane Remodeling by Human Ovarian Surface Epithelial Cells
Ovarian Cancer and Tumor Biology Programs, Department of Medical Oncology, Fox Chase Cancer Center, Philadelphia, Pennsylvania
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ABSTRACT |
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 Top ABSTRACT INTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONREFERENCES |
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and IL-1ß (to a lesser extent) were found to drastically increase urokinase type plasminogen activator (uPA) and matrix metalloproteinase (MMP)-9 activities secreted from HOSE cells. MMP-2, the other major HOSE cell-secreted gelatinase, is constitutively produced but not regulated. As demonstrated by immunofluorenscence staining and Western blot analysis, TNF- treatment caused the degradation and structural reorganization of collagen IV and laminin secreted and deposited by HOSE cells in culture. Amiloride, an uPA inhibitor, not only inhibited the activity of uPA but was also able to suppress TNF--stimulated MMP-9 activity and prevented the TNF--stimulated remodeling of the basement membrane extracellular matrix, suggesting the contribution of uPA-mediated proteolytic cascade in this process. This study implicates the potential roles of TNF-, uPA, and MMP-9 in ovarian surface epithelial basement membrane degradation and remodeling, which are processes during ovulation and may contribute to epithelial transformation. The findings may underscore the importance of TNF-, uPA, and MMP-9 in ovarian surface epithelial basement membrane remodeling and may provide a molecular mechanism linking ovulation and ovarian cancer risk. |
INTRODUCTION |
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TopABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONREFERENCES |
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Ovulation, triggered by luteinizing hormone (LH), is a complex process involving reciprocal paracrine interactions between surface epithelial cells and multiple stromal cell types (4
, 7 , 11
, 12)
, resulting in the degradation of the basement membranes of the follicular wall and surface epithelium at a definite surface location (apex) followed by the expulsion of the oocyte. Proteolytic degradation of the basement membrane and connective tissue of the ovarian wall during follicular rupture is similar to an inflammatory process (11
, 13, 14, 15)
. An influx of immune cells and increased concentration of cytokines and proteases occur during the LH peak. TNF- is one of the main cytokines involved in this process and has emerged as a putative mediator of ovulation (13, 14, 15)
, synergizing with LH to induce ovulation. Other potential autocrine- and paracrine-mediating factors involved in ovulation include interleukin (IL)-1ß (16)
, platelet-activating factor (PAF; Ref. 17
), and prostaglandins (11
, 12)
.
Previous studies have provided circumstantial evidence that the ovarian surface epithelium actively participates in ovulation by secreting proteolytic enzymes (4 , 11 , 12) . This proteolytic degradation begins at the basal surface of the ovarian surface epithelium and advances inward toward the follicle. In cell culture, Kruk et al. (10) have demonstrated the capacity of human ovarian surface epithelial (HOSE) cells to secrete serine proteases and matrix metalloproteinases (MMPs), as well as to lyse Matrigel, although how these activities are regulated has not been explored. Several lines of evidence have implicated that both the MMP and plasminogen activator system contribute to the proteolytic activity needed at the time of ovarian rupture during ovulation (11 , 12) , e.g., an increase in plasminogen activator and MMP activities has been detected during the preovulatory period (18, 19, 20) , and synthetic MMP inhibitors suppressed ovulation in perfused rat ovaries (21 , 22) .
It has been proposed that the loss of basement membrane is a critical early step in the neoplastic transformation of ovarian surface epithelial cells (23, 24, 25) . The cellular mechanisms that lead to basement membrane breakdown during neoplastic transformation and ovulation have been speculated to be similar (25) . In the present study, we sought to evaluate the roles of HOSE cells and a number of potential local mediators of ovulation in the production of basement membrane hydrolyzing proteases and degradation of the basement membrane. Results from the current study may reveal factors and mechanisms involved in the loss of ovarian surface epithelial basement membrane in ovulation and neoplastic morphological transformation.
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MATERIALS AND METHODS |
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TopABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONREFERENCES |
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, IL-1ß, follicle-stimulating hormone (FSH), and LH were purchased from Calibiochem (La Jolla, CA). Prostaglandin factor (PGF)2 was purchased from Cayman Chemical (Ann Arbor, MI). Carbamyl (c)-PAF, a nonhydrolyzable PAF, was purchased from Biomol (Plymouth Meeting, PA). All reagents, unless otherwise specified, were purchased from Sigma (St. Louis, MO).
Cell Culture.
Primary HOSE cells were prepared from prophylactic oophorectomies, and the cells were transfected with SV40 large T antigen to prolong life span (24)
. Although these cells were prepared from disease-free "normal" ovaries, the cells likely contain BRCA1 or BRCA2 mutations (25)
and may be highly abnormal in terms of growth properties and tumor-prone phenotypes. Three "immortalized" HOSE cell lines, HIO-80, HIO-114, and HIO-105, were cultured in medium 199 and MCDB 105 (1:1) supplemented with 5% fetal bovine serum, 0.25 unit/ml insulin, 2 mM L-glutamine, 100 units/ml penicillin, and 100 µg/ml streptomycin. Cultures were maintained in a humidified atmosphere of 95% air/5% CO2 at 37°C.
For Western blot analysis and gel zymography, confluent cells cultured in 60-mm plates were washed twice with PBS and switched to serum-free medium immediately before treatment with either TNF- (10 ng/ml), IL-1ß (5 ng/ml), PGF2 (50 nM), c-PAF (10 nM), or LH (10 nM). To prepare lysates, cells were rinsed twice with PBS and lysed in 1 x SDS sample buffer [62.5 mM Tris (pH 6.8), 10% Glycerol, 1% SDS, and 0.1% Bromphenol Blue]. Conditioned medium was collected at the time indicated and concentrated 4-fold using a Centricon 10 concentrator (Amicon, Beverly, MA) before analysis. All experiments were done using all three HIO lines, and the results show quantitative variation between the lines, but the main conclusions from each treatment remain the same.
Western Blot Analysis.
Total cell lysates were used for analyzing the expression of MMP-14, collagen IV, or laminin; concentrated conditioned medium mixed with sample buffer [0.25 M Tris, (pH 6.8), 40% glycerol, 4% SDS, and 0.4% bromphenol blue] at 3:1 ratio was used for MMP-2, MMP-9, MMP-14, MMP-19, tissue inhibitor of MMP (TIMP)-1, TIMP-2, or urokinase type plasminogen activator (uPA) analysis. Samples were boiled for 5 min and then loaded on 10% SDS polyacrylamide gel under reducing conditions (10 mM DTT). After electrophoresis, the proteins were electrotransferred to polyvinylidene difluoride membranes (Bio-Rad, Hercules, CA), and nonspecific binding sites were blocked by incubating the membranes overnight at 4°C in 10 mM Tris (pH 7.5), containing 0.15 M NaCl, 0.05% Triton X-100, and 5% nonfat dry milk. The membrane was incubated with primary antibodies raised against collagen IV, Laminin, MMP-2, MMP-9, MMP-14, MMP-19, TIMP-1, TIMP-2, or uPA (Oncogene, San Diego, CA) for 1 h. Membranes were then probed with peroxidase-labeled goat antimouse IgG (Kirkegaard & Perry Laboratories, Gaithersburg, MD) for 45 min. The signal was revealed using a chemiluminescence detection system (Pierce, Rockford, IL).
Gelatin and Casein Zymography.
Concentrated condition medium was analyzed in nonreducing conditions on SDS-PAGE gels copolymerized with 0.1% gelatin for gelatinase and collagenase activities and 0.1% casein for plasminogen activator activities. After electrophoresis, the gels were washed three times with 2.5% Triton X-100 for 15 min at room temperature to remove SDS. Gels were then incubated in the development buffer [50 mM Tris-HCl (pH 7.5), 200 mM NaCl, 5 mM CaCl2, and 0.02% Brij-35] at 37°C for 16 h. The enzyme activity was visualized by staining the gel with 0.1% (w/v) Coomassie brilliant blue R-250 in 40% (volume for volume) methanol/10% (volume for volume) acetic acid for 2 h and destained in 10% (volume for volume) methanol with 7% acetic acid until bands became clear.
Immunofluorescence Microscopy.
Human "immortalized" ovarian surface epithelial cells were grown to confluence on chamber slides and maintained for an additional 4 days with daily addition of 50 µg/ml ascorbate to promote collagen secretion. Cells were then treated as indicated for various times. At the end of treatment, the cultures were permeabilized in PBS containing 0.5% Triton X-100 and 5% sucrose for 3 min and then fixed in PBS containing 4% paraformaldehye and 5% sucrose for 20 min, followed by washing with PBS. After blocking in 20% donkey serum (Jackson Immuno-Research Laboratories, West Grove, PA), the cultures were incubated with collagen IV monoclonal antibody (1:500; Sigma) for 1 h. After a 30-min PBS wash, the cultures were stained with FITC-conjugated donkey antimouse IgG (1:400; Jackson ImmunoResearch Laboratories) for 45 min. Propidium iodide (Molecular Probes, Eugene, OR) nuclear staining was then performed according to the manufacturer’s instruction. Samples were mounted using the Prolong Antifade Kit (Molecular Probes) and examined using confocal microscopy.
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RESULTS |
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TopABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONREFERENCES |
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., IL-1ß, PGF2, and PAF, have also been implicated as potential mediators of ovulation (11
, 12)
. Functional analyses indicate that uPA is involved in tissue degradation, whereas tissue-type plasminogen activator is involved in thrombolysis (26
, 27)
. To further investigate the role of ovarian surface epithelial cells in basement membrane degradation, we therefore sought to determine whether these potential mediators affect uPA production from HOSE cells. LH, which has been shown to induce uPA secretion from sheep OSE, was also tested in the study. Human nontumorigenic ovarian surface epithelial HIO-80 cells were treated with either vehicle control, TNF- (10 ng/ml), IL-1ß (5 ng/ml), PGF2 (50 nM), c-PAF (10 nM), or LH (10 nM). At 4, 7, and 18 h after treatment, conditioned media were collected and analyzed by Western blot for the presence of uPA. As shown in Fig. 1A
, marked induction of uPA protein (Mr 50,000) occurs 4 and 7 h after TNF- or IL-1ß treatment, whereas PGF2, LH, or c-PAF treatment had negligible effect. At 18 h, a significant increase in this endogenous uPA proteins (Mr 50,000) was observed compared with earlier time points in all experimental conditions, indicating that HOSE cells constitutively secrete this Mr 50,000 precursor form (single chain) of uPA. This precursor form can be activated to the two-chain form to become active high molecular weight uPA (HMW-uPA, Mr 100,000). The HMW-uPA can be further processed by removal of an NH2-terminal fragment to produce an active low molecular weight form (LMW-uPA, Mr 33,000; Refs. 26
and 27
). Induction of the HMW-uPA (Mr 100,000) and LMW-uPA (Mr 33,000) were detected exclusively in response to TNF- treatment. The generality of TNF--induced uPA production in HOSE cells was tested using additional HOSE cell preparations. As shown in Fig. 1B
, induction of Mr 50,000; 75,000; and 100,000 uPA was observed 18 h after TNF- treatment in HIO-105 cells.
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, two major gelatinase species, Mr 68,000 and 88,000, are present in conditioned medium, and both activities accumulated with time. However, the Mr 68,000 activity was not affected by the treatments administered in the current study, including TNF-, IL-1ß, PGF2, c-PAF, and LH. Both TNF- and IL-1ß caused a time-dependent increase in the Mr 88,000 gelatinase activity (Fig. 2A)
, although the effect of IL-1ß was much weaker than TNF- at any given time point. PGF2, c-PAF, and LH had no effect on gelatinase activity under our experimental conditions.
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-treated HOSE cells. As shown in Fig. 2B
, gelatinase activities in both control and TNF--treated cell lysates were negligible and much weaker than that from conditioned media, indicating that the majority of collagenase activity in HOSE cells is secreted, and cell-associated MMP is negligible. In addition, TNF- appears to affect the activity of secreted, rather than cell-associated MMPs.
TNF--Stimulated Secretion of MMP-9 from HOSE Cells.
On the basis of the molecular weight (10
, 27
, 28)
, it is possible that the Mr 68,000 collagenase in the conditioned medium is MMP-2 and the Mr 88,000 activity is MMP-9. The identity of TNF--stimulated Mr 88,000 gelatinase activity was furthered confirmed by Western blot analysis. Similar to the stimulation pattern observed from gelatin zymography, a time-dependent increase of the Mr 88,000 protein recognized by MMP-9-specific antibody was observed in response to either TNF- or IL-1ß treatment (Fig. 3A)
. Again, much stronger induction was elicited by TNF- compared with IL-1ß. Stimulation of MMP-9 production by TNF- was also observed in other HOSE cells: (a) immunoblotting in HIO-114 cells (Fig. 3B)
; and (b) gelatin zymography in HIO-105 cells (Fig. 3C)
. Quantitative but not qualitative variations of MMP-9 production in response to TNF- were observed in different preparations of HIO cells.
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on the expression of other MMP proteins and the TIMP. Consistent with the results shown on zymographs, TNF- did not alter the level of the Mr 68,000 MMP-2 protein, nor did it alter MMP-14, TIMP-1, and TIMP-2 protein expression (Fig. 4A)
.
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-, IL-1ß-, PGF2-, c-PAF-, and LH-treated HOSE cells. TNF- elicited a small increase in MMP-19 protein with the appearance of Mr 45–47,000; 37,000; and 28,000 forms (Fig. 4B)
. Additionally, the secreted MMP-19 from HOSE cells did not exhibit any significant gelatinase activity compared with MMP-2 and MMP-9 as analyzed by zymography. Nevertheless, on the basis of its regulation by TNF- and expression during ovulation, MMP-19 may have a regulatory role, such as the activator of a protease cascade in tissue remodeling during ovulation.
Remodeling of HOSE Cell-Secreted Basement Membrane Matrix by TNF-.
The induction of uPA, MMP-9, and MMP-19 by TNF- prompted us to investigate the effect of TNF- on the integrity of the basement membrane reflected by the structure of extracellular type IV collagen. On culturing on tissue culture chamber slides for 4 days, confluent HOSE cells secrete a basement membrane-like extracellular matrix. This fine plexus of wispy strands can be maintained for 
1 week. TNF- was added to the culture after HOSE cells had secreted and deposited a layer of basement membrane matrix. As shown by immunofluorescence microscopy, the type IV collagen in the control culture appeared to be a delicate, foamy fine lacework surrounding the HOSE cells (Fig. 5)
. TNF- treatment for 22 h caused condensation of type IV into much heavier branched beams separated by expanses with negligible amount of collagen (Fig. 5)
. Longer TNF- treatment (60 h) resulted in a substantial reduction in the density and branching of collagen IV accompanied by thickening of remaining strands. To determine whether TNF- treatment caused a quantitative difference on the level of basement membrane components, extracellular matrix was isolated together with cell lysate using SDS sample buffer 22 h after TNF- treatment. The levels of collagen IV and laminin protein were determined by Western blot analysis. As shown in Fig. 6
, a significant decrease in collagen IV (2.5-fold) and laminin (3.8-fold) protein was observed after TNF- treatment. Results from these experiments indicate that TNF- treatment of the cells is capable of inducing the degradation, reducing the density, and altering the structural organization of type IV collagen in vitro.
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-Stimulated uPA and MMP-9 Activities and Collagen IV Remodeling by Amiloride.-induced MMP-9 activity, cells were pretreated with either amiloride (200 µM), a competitive uPA inhibitor (31)
; celecoxib (5 µM), a COX-2-specific inhibitor (32)
; or MK886 (20 nM), a specific inhibitor of 5-lipoxygenase-activating protein (33)
for 1 h before TNF- treatment. Medium was collected 18 h after treatment and assayed for uPA and MMP activities by casein and gelatin zymography, respectively. As expected, amiloride blocked TNF--induced uPA activity (Mr 50,000 and 100,000), whereas the other inhibitors had no effect (Fig. 7A)
. Inhibition of uPA activity by amiloride was also accompanied by 90% reduction of TNF--induced MMP-9 activity without any observable effect on MMP-2 activity (Fig. 7B)
. Celecoxib and MK886 exerted no effect on TNF--stimulated MMP-9 activity (Fig. 7B)
, indicating that the arachidonic pathway is not involved in TNF--stimulated MMP-9 production. When Western blotting was performed using the same set of conditioned medium, we observed a substantial reduction in TNF--stimulated MMP-9 level but not MMP-2 protein expression by amiloride (Fig. 7C)
. Results from this study demonstrate that amiloride is capable of inhibiting TNF--stimulated uPA and MMP-9 activity.
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-induced structural change of type IV collagen, the effect of amiloride on TNF--induced type IV collagen remodel was monitored. After culture of HOSE cells for 4 days to produce and deposit a layer of basement membrane matrix, the cells were incubated in the presence or absence of amiloride (200 µM) 1 h before the addition of TNF-. Immunofluorescence staining was performed 22 h after TNF- treatment. Collagen IV immunofluorescence microscopy in Fig. 8
illustrates that amiloride prevented TNF--induced structural change of type IV collagen. In the presence of amiloride, the condensation of fine collagen IV fibers into coarse beams and empty areas after TNF- treatment was prevented. Because amiloride inhibits the activities of MMP-9 and uPA, results from this study suggest that uPA and MMP-9 are involved in TNF--induced remodeling of type IV collagen basement membrane matrix.
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DISCUSSION |
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TopABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONREFERENCES |
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. This increase in proteolytic activity was associated with degradation and remodeling of type IV collagen, the major component of basement membrane. Amiloride, a uPA inhibitor, shown to inhibit both uPA and MMP-9 activity in the present study, is also able to alleviate TNF--induced structural change of type IV collagen, suggesting the involvement of uPA/MMP-9 cascade in TNF--stimulated structural reorganization of type IV collagen. Additional studies are needed to define whether MMP-19 is necessary in this degradation process and its contribution to the overall proteolytic activity. All of the experiments described in this study have been carried out in all three cell lines: (a) HIO-80; (b) HIO-105; and (c) HIO-114. The conclusions are essentially identical in all three lines, with quantitative variations. It was observed that HIO-80 is the most and HIO-114 is the least responsive to TNF- stimulation.
TNF-, a pleiotropic polypeptide cytokine, is secreted from activated macrophages, as well as from several nonimmune cells in the ovary, such as granulosa and thecal cells (13, 14, 15)
. An increase in the concentration of TNF- has been observed as ovulation occurs. TNF- might access the HOSE by way of either the pelvic cavity (peritoneal fluid) or ovarian vasculature. Cells in close proximity to the preovulatory follicle (i.e., within a limited diffusion radius) are probably exposed preferentially to the increased concentration of TNF-, because of an acute increase in permeability of thecal vascular wreath. Mechanisms regulating TNF- expression and release from resident ovarian cells remain controversial. It has been speculated that increased secretion of uPA by ovarian surface epithelial cells contiguous with the preovulatory follicles elicits a localized increase in tissue plasmin, which will release TNF- from its anchor along the thecal endothelium (13, 14, 15)
.
The initiation of ovulation is induced by LH and FSH (11
, 12)
. In the current study, we have not observed the induction of protease activities by LH and/or FSH in all three HOSE cell lines. A significant increase of uPA and MMP-9 secretion from HOSE cells was detected in response to TNF- but not LH. Thus, we believe that LH and FSH do not induce the expression of uPA and MMPs directly in HOSE cells. TNF- produced from other ovarian cell types that is induced by LH and FSH is thus a likely mediator for the induction of proteolytic activities from HOSE cells. Such an ovarian paracrine regulation may be required for the determination of a selective numbers of follicles in each ovulatory gonadotropin stimulation.
Previous studies from Kruk et al. (10)
demonstrated the expression of MMP-1 (collagenase), MMP-2 (gelatinase), and MMP-3 (stromelysin) RNA from OSE cells. Here, we further demonstrate that MMP-9 is the TNF--induced collagenase activity.
Amiloride is a potassium-sparing diuretic agent used clinically in the treatment of hypertension and has been shown to competitively inhibit the catalytic activity of uPA but not tissue-type plasminogen activator (31)
. In the present study, we have observed that inhibition of uPA activity by amiloride is associated with a 90% inhibition of MMP-9 activity, as well as a substantial decrease in MMP- 9 protein expression. In fact, uPA-dependent plasminogen plasmin system has been described to cleave proMMP, which results in its activation (26
, 27
, 30)
. The mechanisms accounting for amiloride-mediated inhibition of MMP-9 protein secretion are not clear. Accumulating evidence demonstrates that the transcription factors, AP-1 and nuclear factor-
B, are necessary for induction of MMP-9 expression (34
, 35)
. Amiloride has been shown to inhibit nuclear translocation and activation of nuclear factor-B (35)
. It is therefore possible that inhibition of TNF--induced MMP-9 protein secretion by amiloride is mediated at the transcriptional level. Further study is needed to address this possibility.
Collagen IV turnover and remodeling are ubiquitous features of normal basement membrane matrix metabolism and reflects a balance between synthetic events, including biosynthesis, secretion, and assembly, and degradative events mediated by serine proteases and MMPs. In the present study, we observed that TNF- treatment caused degradation and branching of collagen IV associated with thickening of the remaining strands. A reduction in collagen IV surrounding HOSE after TNF- treatment may reflect one or the combination of the following: (a) a reduction in the biosynthesis or assembly of new collagen IV; (b) an increase in collagen IV degradation; and (c) differential changes in both parameters (the rate of degradation exceeds the rate of synthesis). Given the fact that the MMP-9- and uPA-mediated cascade is capable of degrading type IV collagen and a uPA inhibitor prevents the structural change in collagen IV matrix, it is plausible that TNF- accelerated the rate of collagen IV degradation over the rate of its synthesis. Because MMPs are also required for collagen remodeling, the associated thickening of the remaining strands suggests TNF--induced MMP-9 may also affect the machinery of type IV collagen assembly. Such a condensation, with an associated increase in uncovered spaces seen in vitro, may be analogous to the loss of basement membrane seen in situ during the process of ovulation and tumorigenesis.
A previous study in our laboratory has shown that the basement membrane is often absent from preneoplastic ovarian surface epithelia located immediately adjacent to a morphologically neoplastic lesion, suggesting that the loss of the basement membrane is an early step toward the ovarian tumorigenicity (23)
. Thus, frequent loss of basement membrane in repeated ovulation, which is induced by gonadotropins and mediated by TNF-, may increase the chance of ovarian surface epithelial cell transformation. The etiological link between ovarian cancer risk to incessant ovulation (36)
or gonadotropin stimulation (37)
is well established. Thus, TNF--stimulated basement membrane loss provides a mechanistic explanation for the incessant ovulation hypothesis. Additionally, prolonged exposure to TNF- during pathophysiological conditions, such as inflammation and chronic gonadotropin stimulation, may promote ovarian carcinogenesis. An increase of proinflammatory cytokines, including TNF-, occurs after natural and surgical menopause (38)
. The link between TNF- exposure and basement membrane loss may provide an explanation that an increase in circulating TNF- may be a contributing factor for a higher risk of ovarian cancer in postmenopausal women.
In conclusion, this study suggests that factors involved in ovulation, such as TNF-, uPA, and MMP-9, may modulate ovarian cancer risk by their roles in the degradation of basement membrane. Because ovulation-like loss of basement membrane is a possible etiological mechanism in ovulation-associated ovarian cancer risk (25)
, this study underscores the importance of TNF-, uPA, and MMP-9 in ovarian surface epithelial basement membrane remodeling and may provide a molecular mechanism linking ovulation and ovarian cancer risk. Thus, these factors are also possible targets for chemopreventive intervention of ovarian cancer.
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ACKNOWLEDGMENTS |
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FOOTNOTES |
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The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked advertisement in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
Requests for reprints: Dr. Xiang-Xi Xu, Ovarian Cancer and Tumor Cell Biology Programs, Department of Medical Oncology, Fox Chase Cancer Center, 333 Cottman Avenue, Philadelphia, PA 19111-2497. Phone: (215) 728-2188; Fax: (215) 728-2741; E-mail: X_Xu{at}fccc.edu
Received 9/16/03. Revised 11/24/03. Accepted 12/ 9/03.
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REFERENCES |
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TopABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONREFERENCES |
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(TNF) on ovulation in the rat ovary. Reprod. Fertil. Dev., 7: 67-73, 1995.[CrossRef][Medline]
in the ovulatory mechanism of ewes. J. Anim. Sci., 75: 1601-1605, 1997./Nf-kb-dependent mechanism. Am. J. Respir. Cell Mol. Biol., 26: 114-126, 2002.This article has been cited by other articles:
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  M. J. Duffy, E. McKiernan, N. O'Donovan, and P. M. McGowan Role of ADAMs in Cancer Formation and Progression Clin. Cancer Res., February 15, 2009; 15(4): 1140 - 1144. [Abstract] [Full Text] [PDF]
|
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 |
|
 P. M. McGowan, E. McKiernan, F. Bolster, B. M. Ryan, A. D. K. Hill, E. W. McDermott, D. Evoy, N. O'Higgins, J. Crown, and M. J. Duffy ADAM-17 predicts adverse outcome in patients with breast cancer Ann. Onc., June 1, 2008; 19(6): 1075 - 1081. [Abstract] [Full Text] [PDF]
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|
 |
|
 S. Zecchini, M. Bianchi, N. Colombo, R. Fasani, G. Goisis, C. Casadio, G. Viale, J. Liu, M. Herlyn, A. K. Godwin, et al. The Differential Role of L1 in Ovarian Carcinoma and Normal Ovarian Surface Epithelium Cancer Res., February 15, 2008; 68(4): 1110 - 1118. [Abstract] [Full Text] [PDF]
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|
|
|
 |
|
 D. L. Russell and R. L. Robker Molecular mechanisms of ovulation: co-ordination through the cumulus complex Hum. Reprod. Update, May 1, 2007; 13(3): 289 - 312. [Abstract] [Full Text] [PDF]
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P. M. McGowan, B. M. Ryan, A. D.K. Hill, E. McDermott, N. O'Higgins, and M. J. Duffy ADAM-17 Expression in Breast Cancer Correlates with Variables of Tumor Progression Clin. Cancer Res., April 15, 2007; 13(8): 2335 - 2343. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. T. Rae, O. Gubbay, A. Kostogiannou, D. Price, H. O. D. Critchley, and S. G. Hillier Thyroid Hormone Signaling in Human Ovarian Surface Epithelial Cells J. Clin. Endocrinol. Metab., January 1, 2007; 92(1): 322 - 327. [Abstract] [Full Text] [PDF]
|
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|
|
 |
|
 T. Hagemann, J. Wilson, F. Burke, H. Kulbe, N. F. Li, A. Pluddemann, K. Charles, S. Gordon, and F. R. Balkwill Ovarian cancer cells polarize macrophages toward a tumor-associated phenotype. J. Immunol., April 15, 2006; 176(8): 5023 - 5032. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 W. J. Murdoch Carcinogenic Potential of Ovulatory Genotoxicity Biol Reprod, October 1, 2005; 73(4): 586 - 590. [Abstract] [Full Text] [PDF]
|
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|
|
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 C. H. Stuelten, S. D. Byfield, P. R. Arany, T. S. Karpova, W. G. Stetler-Stevenson, and A. B. Roberts Breast cancer cells induce stromal fibroblasts to express MMP-9 via secretion of TNF-{alpha} and TGF-{beta} J. Cell Sci., May 15, 2005; 118(10): 2143 - 2153. [Abstract] [Full Text] [PDF]
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E. Wang, Y. Ngalame, M. C. Panelli, H. Nguyen-Jackson, M. Deavers, P. Mueller, W. Hu, C. A. Savary, R. Kobayashi, R. S. Freedman, et al. Peritoneal and Subperitoneal Stroma May Facilitate Regional Spread of Ovarian Cancer Clin. Cancer Res., January 1, 2005; 11(1): 113 - 122. [Abstract] [Full Text] [PDF]
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