Expression of various matrix proteases and Ets family transcriptional factors in ovarian cancer cell lines: correlation to invasive potential

The role of MMP-14 in ovarian cancer: a systematic review

AIM

In order to evaluate the role of MMP-14 in ovarian cancer, a systematic review was conducted.

METHODS

In March 2020, a search in Pubmed was performed with MMP-14 and ovarian cancer as search terms. After exclusion of the references not on MMP-14 or ovarian cancer or not in English, the studies found were classified into two categories: basic research and clinicopathological research.

RESULTS

In total, 94 references were found of which 33 were excluded. Two additional articles were found in the reference lists of the included studies. Based on the full texts, another 4 were excluded. Eventually, 59 studies were included in the review, 32 on basic research and 19 on clinicopathological research. 8 studies fell in both categories. The basic research studies show that MMP-14 plays an important role in ovarian cancer in the processes of proliferation, invasion, angiogenesis and metastasis. In clinocopathological research, MMP-14 expression is found in most tumours with characteristics of poor prognosis but this immunohistochemical MMP-14 determination does not seem to be an independent predictor of prognosis.

CONCLUSIONS

From this systematic review of the literature concerning MMP-14 in ovarian cancer it becomes clear that MMP-14 plays various important roles in the pathophysiology of ovarian cancer. The exact translation of these roles in the pathophysiology to the importance of MMP-14 in clinicopathological research in ovarian cancer and possible therapeutic role of anti-MMP-14 agents needs further elucidation.

ETV4 Facilitates Cell-Cycle Progression in Pancreatic Cells through Transcriptional Regulation of Cyclin D1

The ETS family transcription factor ETV4 is aberrantly expressed in a variety of human tumors and plays an important role in carcinogenesis through upregulation of relevant target gene expression. Here, it is demonstrated that ETV4 is overexpressed in pancreatic cancer tissues as compared with the normal pancreas, and is associated with enhanced growth and rapid cell-cycle progression of pancreatic cancer cells. ETV4 expression was silenced through stable expression of a specific short hairpin RNA (shRNA) in two pancreatic cancer cell lines (ASPC1 and Colo357), while it was ectopically expressed in BXPC3 cells. Silencing of ETV4 in ASPC1 and Colo357 cells reduced the growth by 55.3% and 38.9%, respectively, while forced expression of ETV4 in BXPC3 cells increased the growth by 46.8% in comparison with respective control cells. Furthermore, ETV4-induced cell growth was facilitated by rapid transition of cells from G₁- to S-phase of the cell cycle. Mechanistic studies revealed that ETV4 directly regulates the expression of Cyclin D1 CCND1, a protein crucial for cell-cycle progression from G₁- to S-phase. These effects on the growth and cell cycle were reversed by the forced expression of Cyclin D1 in ETV4-silenced pancreatic cancer cells. Altogether, these data provide the first experimental evidence for a functional role of ETV4 in pancreatic cancer growth and cell-cycle progression.Implications: The functional and mechanistic data presented here regarding ETV4 in pancreatic cancer growth and cell-cycle progression suggest that ETV4 could serve as a potential biomarker and novel target for pancreatic cancer therapy. Mol Cancer Res; 16(2); 187-96. ©2017 AACR.

Allicin inhibits cell migration and invasion in human hepatocellular carcinoma cell line MHCC97H

AIM: To observe the effect of allicin on the proliferation, migration and invasion of human hepatocellular carcinoma cell line MHCC97H and to explore the underlying mechanisms.

METHODS: MTT assay and transwell assay were used to assess the proliferation, migration and invasiveness of MHCC97H treated with varying concentrations of allicin for 24 h. Real-time fluorescence quantitative PCR was performed to detect the mRNA expression of MMP-2, MMP-9 and CD24.

RESULTS: MTT assay demonstrated that the proliferation of MHCC97H cell was inhibited by different concentrations of allicin. Transwell assay demonstrated that compared with the negative control group, the number of penetrating cells in the experimental group was decreased significantly (P < 0.01). Real-time fluorescence quantitative PCR showed that allicin could down-regulate the mRNA levels of MMP-2, MMP-9, and CD24 in a dose-dependent manner in MHCC97H cells (P < 0.01).

CONCLUSION: Allicin inhibits the proliferation, migration and invasion of MHCC97H cells via mechanisms possibly related to down-regulation of the mRNA expression of MMP-2, MMP-9, and CD24.

Mast cell chymase is present in uterine cervical carcinoma and it detaches viable and growing cervical squamous carcinoma cells from substratum in vitro

Increased numbers of mast cells is a typical feature of a variety of human cancers. The major mediators in the secretory granules of the MC(TC) type of mast cells, serine proteinases tryptase and chymase, may be involved in squamous cell carcinoma (SCC) lesions by inducing matrix remodeling and epithelial cell detachment. The objective of this study was to analyze immunohistochemically whether MC(TC) mast cells as well as protease inhibitors, squamous cell carcinoma antigens (SCCAs), are present in the uterine cervical SCC. In addition, the effect of tryptase and chymase on uterine cervical SCC cell lines was studied in vitro. Here we report that tryptase- and chymase-positive mast cells are present in significant numbers in the peritumoral stroma of SCC lesions. Also, weak SCCA-2 immunoreactivity is observed in the SCC lesions, but only SCCA-1 in uterine cervical specimens with nonspecific inflammation. In cell cultures, especially chymase, but not tryptase, was shown to induce effective detachment of viable, growing and non-apoptotic SiHa SCC cells from substratum. Chymase also detached viable ME-180 SCC cells from substratum as well as degraded fibronectin. In contrast, normal keratinocytes underwent apoptotic cell death after similar prolonged chymase treatment. No inhibition of chymase was detected by SiHa cell sonicates nor did these cells express marked SCCA immunopositivity. MC(TC) mast cells containing tryptase and chymase are present in the peritumoral stroma of uterine cervical SCC and the malignant cells are only weakly immunoreactive for the chymase inhibitor SCCA-2. It is chymase that appears to be capable of inducing effective detachment of viable and growing SCC cells and therefore, it may release SCC cells from a tumor leading to spreading of malignant cells.

MMP-1-PAR1 axis mediates LPA-induced epithelial ovarian cancer (EOC) invasion

OBJECTIVES

MMP-1 is over-expressed in many cancers, with high expression often associated with poor survival. In the present study, we examined the expression of MMP-1 in EOC and its role in EOC invasion. Moreover, we evaluated the role of a newly identified MMP-1-protease activated receptor (PAR)-1 axis in LPA-induced EOC invasion.

METHODS

MMP-1 and PAR1 mRNA expression in EOC cell lines was determined by real time PCR. MMP-1 mRNA expression in 96 normal and carcinoma ovarian tissue specimens was analyzed using a TissueScan real time PCR array. MMP-1 concentration in conditioned medium was measured by MMP-1 ELISA. PAR1 protein expression was detected by Western blotting. Cell invasion was evaluated by in vitro Matrigel invasion assay.

RESULTS

In ovarian tumor tissues more MMP-1 expression was observed than in normal ovarian tissues (p<0.05), and its expression correlated with tumor grade (grade 3>grade 2>grade 1). Human recombinant MMP-1 as well as serum free conditioned medium containing high levels of MMP-1 from DOV13 and R182 cells significantly promoted DOV13 cell invasion (p<0.05), implicating a direct role of MMP-1 in EOC invasion. Moreover, MMP-1 induced DOV13 invasion was significantly blocked by PAR1 siRNA silencing. Furthermore, MMP-1 and PAR1 were both significantly induced by LPA (20 μM), and siRNA silencing of MMP-1 and PAR1 both significantly reduced LPA's invasion-promoting effect in DOV13 cells (p<0.05).

CONCLUSIONS

Our results suggest that the MMP-1-PAR1 axis is involved in EOC invasion and at least partially mediates LPA-induced EOC invasion. Therefore, blocking MMP-1 or PAR1 may represent a new therapeutic option for metastatic EOC.

Expression of the constitutively activated RelA/NF-kappaB in human astrocytic tumors and the in vitro implication in the regulation of urokinase-type plasminogen activator, migration, and invasion

Although malignant gliomas are highly invasive tumors, a characteristic that contributes to the commonly observed therapeutic failures and local disease recurrences, the molecular events that regulate invasion in these tumors remain poorly understood. Because the transcription factor RelA/NF-kappaB has been shown to regulate invasion during several cellular processes, we have examined immunohistochemically expression of the constitutively activated RelA/NF-kappaB in tissues obtained from 49 astrocytic tumors [8 diffuse astrocytomas, 9 anaplastic astrocytomas (AAs) and 32 glioblastomas (GBMs)]. In addition, we examined the in vitro effects of antisense oligonucleotides and curcumin on the expression and activation of RelA/NF-kappaB, urokinase-type plasminogen activator (u-PA) expression, migration, and invasion in the T98G glioma cell line. Expression of the constitutively activated RelA/NF-kappaB was observed in 2 (25%) of 8 cases of diffuse astrocytomas, 5 (55.6%) of 9 cases of AAs, and 30 (93.8%) of 32 cases of GBMs. This expression was significantly correlated with the malignant potential in astrocytic tumors (P < 0.001). Moreover, antisense oligonucleotides and curcumin inhibited phorbol-12-myristate-13-acetate (PMA)-induced RelA/NF-kappaB expression or activation (or both), down-regulated u-PA expression, and reduced the migration and invasive potentials of T98G glioma cells. Thus, the expression of constitutively activated RelA/NF-kappaB is associated with malignancy potential in astrocytic tumors and may play a critical role in the regulation of u-PA expression and invasiveness in gliomas. RelA/NF-kappaB may therefore be an intriguing candidate for studies aimed at understanding and prevention of the invasiveness of gliomas.

ERM/ETV5 up-regulation plays a role during myometrial infiltration through matrix metalloproteinase-2 activation in endometrial cancer

We have described recently the Ets family transcription factor, ERM/ETV5, specifically up-regulated in endometrioid endometrial carcinoma (EEC) and associated with myometrial infiltration. Ets family members have been correlated to tumor progression by up-regulating the expression of matrix-degrading proteases. In the present study, we investigated the possibility that in EEC, ERM/ETV5 may act by inducing the expression of genes involved in extracellular matrix remodeling. Unraveling the molecular events associated with the initiation of tumor invasion would represent an obvious improvement for EEC patients. The overexpression of ERM/ETV5 induced scattering in the endometrial cancer cell line Hec-1A, correlating to increased matrix metalloproteinase-2 (MMP-2) gelatinase activity. Both chromatin immunoprecipitation and reversion experiments with RNA interference and specific MMP-2 inhibitor showed a functional link between ERM/ETV5 overexpression and MMP-2 activation. The increased MMP-2 activity associated with overexpressed ERM/ETV5 in a mouse model conferred invasive capacity to endometrial tumors. Orthotopically implanted overexpressing ERM/ETV5 tumors presented a more aggressive and infiltrative pattern of myometrial invasion. Finally, the specific localization of ERM/ETV5 and MMP-2 at the invasive front of myometrial infiltrating human endometrial carcinomas further reinforced the hypothesis of a role for ERM/ETV5 in the early steps of endometrial dissemination. Taken together, these results lead us to propose that in EEC, ERM/ETV5 acts through MMP-2 gelatinolytic activity to confer invasive capabilities, associated with an initial switch to myometrial infiltration. They also postulate ERM/ETV5 as a valuable marker for patient stratification and a transcription pathway that should be evaluated for therapies specifically targeting the initial steps of EEC dissemination.

Coordinated elevation of membrane type 1-matrix metalloproteinase and matrix metalloproteinase-2 expression in rat uterus during postpartum involution

BACKGROUND

The changes occurring in the rodent uterus after parturition can be used as a model of extensive tissue remodeling. As the uterus returns to its prepregnancy state, the involuting uterus undergoes a rapid reduction in size primarily due to the degradation of the extracellular matrix, particularly collagen. Membrane type-I matrix metalloproteinase (MT1-MMP) is one of the major proteinases that degrades collagen and is the most abundant MMP form in the uterus. Matrix metalloproteinase-2(MMP-2) can degrade type I collagen, although its main function is to degrade type IV collagen found in the basement membrane. To understand the expression patterns of matrix metalloproteinases (MMPs) in the rat uterus, we analyzed their activities in postpartum uterine involution.

METHODS

We performed gelatin zymography, northern blot analysis and immunohistochemistry to compare the expression levels of MT1-MMP, MMP-2, matrix metalloproteinase-9 (MMP-9) and the tissue inhibitors of MMPs-1 and 2 (TIMP-1 and TIMP-2) in the rat uterus 18 h, 36 h and 5 days after parturition with their expression levels during pregnancy (day 20).

RESULTS

We found that both MT1-MMP and MMP-2 localized mainly in the cytoplasm of uterine interstitial cells. The expression levels of MT1-MMP and MMP-2 mRNAs and the catalytic activities of the expressed proteins significantly increased 18 h and 36 h after parturition, but at postpartum day 5, their mRNA expression levels and catalytic activities decreased markedly. The expression levels of MMP-9 increased 18 h and 36 h after parturition as determined by gelatin zymography including the expression levels of TIMP-1 and TIMP-2.

CONCLUSION

These expression patterns indicate that MT1-MMP, MMP-2, MMP-9, TIMP-1 and TIMP-2 may play key roles in uterine postpartum involution and subsequent functional regenerative processes.

A polymorphism in the matrix metalloproteinase-1 gene promoter is associated with the prognosis of patients with ovarian cancer

OBJECTIVE

The enzyme matrix metalloproteinase (MMP)-1 is involved in ovarian carcinogenesis. A common guanine insertion-deletion promoter polymorphism within the gene encoding MMP-1 (MMP1) has been suggested to be a candidate gene for ovarian cancer. We investigated whether this common polymorphism can also serve as independent prognostic parameter in a large series of affected women.

METHODS

The MMP1 promoter polymorphism was examined in 151 Caucasian patients with epithelial ovarian cancer using polymerase chain reaction. Results were correlated with clinical data.

RESULTS

No associations were ascertained between the MMP1 polymorphism and tumor stage (P = 1.0, odds ratio [OR] 1.08), lymph node involvement (P = 1.0, OR 0.8), tumor grading (P = 0.2, OR 0.5), and patient's age at diagnosis (P = 1.0, OR 1.04). Besides the clinically established prognosticators, tumor stage and histological grade, presence of the MMP1 polymorphism was associated with a shortened disease-free and overall survival in a univariate Kaplan-Meier analysis (P = 0.01) and a multivariate Cox regression model (P = 0.04).

CONCLUSION

Presence of the MMP1 gene promoter polymorphisms was found to be a negative prognostic parameter in patients with ovarian cancer.

Expression of E26 transformation-specific-1, matrix metalloproteinases-1 and vascular endothelial growth factor in colorectal carcinoma

AIM: To study the expression of E26 transformation-specific-1 (Ets-1), matrix metalloproteinases-1 (MMP-1) and vascular endothelial growth factor (VEGF) in human colorectal carcinoma, and to explore the role of Ets-1 in the angiogenesis and metastasis of carcinoma.

METHODS: The expression of Ets-1, MMP-1 and VEGF were detected in colorectal carcinoma (n = 61) and normal colon tissues (n = 21) by the immunohistochemical method respectively.

RESULTS: Ets-1, MMP-1 and VEGF were negatively expressed in all normal mucosal tissues. The positive rates of Ets-1, MMP-1 and VEGF expression were 75.4%, 78.7% and 82.0% in colorectal carcinoma respectively. No significant correlation was found between their positive rates and tumor′s size as well as the differentiation (P >0.05). The expression of Ets-1, MMP-1 and VEGF were significantly correlated with Duke's staging (χ² = 10.718, P <0.01; χ² = 8.323, P <0.01; χ² = 6.145, P <0.05), the depth of invasion (χ² = 7.705, P <0.01; χ² = 19.101, P <0.01; χ² = 14.707, P <0.01), lymphatic invasion (χ² = 9.333, P <0.01; χ² = 3.965, P <0.05; χ² = 4.638, P <0.05) and distant metastasis (χ² = 5.472, P <0.05; χ² = 4.125, P <0.05; χ² = 5.034, P <0.05). Ets-1 expression was positively associated with MMP-1 and VEGF level (r = 0.447, P <0.01; r = 0.425, P <0.05).

CONCLUSION: Ets-1 was over-expressed in colorectal carcinoma, and its expression was related to clinical staging, invasion and metastasis. Ets-1 expression was also positively related to MMP-1 and VEGF level. Their expression can become referential indexes to predict the malignant behavior of colorectal carcinoma.

Ets-1 expression promotes epithelial cell transformation by inducing migration, invasion and anchorage-independent growth

Ets-1 is the prototype of the family of ETS transcription factors. In human tumors, Ets-1 is expressed in endothelial cells and fibroblasts of the tumor stroma and is proposed to play a role in tumor vascularization and invasion by upregulating expression of matrix-degrading proteases. In human carcinomas, Ets-1 is also expressed by neoplastic cells, but little is known about the functional implications of this observation. We have addressed the role of Ets-1 in epithelial HeLa tumor cells by selecting stably Ets-1 over and underexpressing HeLa cells. Ets-1 expression increases the transformed phenotype of HeLa cells, by promoting cell migration, invasion and anchorage-independent growth, while Ets-1 downregulation reduces cell attachment. In correlation with these results, Ets-1 upregulation increases integrinbeta2 expression but not that of other integrins. These results suggest that, in addition to its role in the tumor stroma, Ets-1 may also promote tumor development and progression by increasing neoplastic transformation.

Altered ErbB receptor signaling and gene expression in cisplatin-resistant ovarian cancer

The majority of ovarian cancer patients are treated with platinum-based chemotherapy, but the emergence of resistance to such chemotherapy severely limits its overall effectiveness. We have shown that development of resistance to this treatment can modify cell signaling responses in a model system wherein cisplatin treatment has altered cell responsiveness to ligands of the erbB receptor family. A cisplatin-resistant ovarian carcinoma cell line PE01CDDP was derived from the parent PE01 line by exposure to increasing concentrations of cisplatin, eventually obtaining a 20-fold level of resistance. Whereas PE01 cells were growth stimulated by the erbB receptor-activating ligands, such as transforming growth factor-alpha (TGFalpha), NRG1alpha, and NRG1beta, the PE01CDDP line was growth inhibited by TGFalpha and NRG1beta but unaffected by NRG1alpha. TGFalpha increased apoptosis in PE01CDDP cells but decreased apoptosis in PE01 cells. Differences in extracellular signal-regulated kinase and phosphatidylinositol 3-kinase signaling were also found, which may be implicated in the altered cell response to ligands. Microarray analysis revealed 51 genes whose mRNA increased by at least 2-fold in PE01CDDP cells relative to PE01 (including FRA1, ETV4, MCM2, AXL, MT3, TRAP1, and FANCG), whereas 36 genes (including IGFBP3, TRAM1, and KRT4 and KRT19) decreased by a similar amount. Differential display reverse transcriptase-PCR identified altered mRNA expression for TCP1, SLP1, proliferating cell nuclear antigen, and ZXDA. Small interfering RNA inhibition of FRA1, TCP1, and MCM2 expression was associated with reduced growth and FRA1 inhibition with enhanced cisplatin sensitivity. Altered expression of these genes by cytotoxic exposure may provide survival advantages to cells including deregulation of signaling pathways, which may be critical in the development of drug resistance.

The conventional nonsteroidal anti-inflammatory drug sulindac sulfide arrests ovarian cancer cell growth via the expression of NAG-1/MIC-1/GDF-15

Although the chemopreventive and antitumorigenic activities of nonsteroidal anti-inflammatory drug (NSAID) against colorectal cancer are well established, the molecular mechanisms responsible for these properties in ovarian cancer have not been elucidated. Therefore, there is an urgent need to develop mechanism-based approaches for the management of ovarian cancer. To this end, the effect of several NSAIDs on ovarian cancer cells was investigated as assessed by the induction of NAG-1/MIC-1/GDF-15, a proapoptotic gene belonging to the transforming growth factor-beta superfamily. Sulindac sulfide was the most significant NSAID activated gene 1 (NAG-1) inducer and its expression was inversely associated with cell viability as determined by 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium assay. This growth suppression by sulindac sulfide was recovered by transfection of NAG-1 small interfering RNA. These results indicate that NAG-1 is one of the genes responsible for growth suppression by sulindac sulfide. Furthermore, we observed down-regulation of p21 WAF1/CIP1 by introduction of NAG-1 small interfering RNA into sulindac sulfide-treated cells. In addition, to elucidate other potential molecular mechanisms involved in sulindac sulfide treatment of ovarian cancer cells, we did a membrane-based microarray experiment. We found that cyclin D1, MMP-1, PI3KR1, and uPA were down-regulated by sulindac sulfide. In conclusion, a novel molecular mechanism is proposed to explain the experimental results and provide a rationale for the chemopreventive activity of NSAIDs in ovarian cancer.

Correlation of tumor- and stromal-derived MT1-MMP expression with progression of human ovarian tumors in SCID mice

OBJECTIVE

Human ovarian carcinoma samples were orthotopically implanted into SCID mice to investigate the contribution of matrix metalloproteases (MMPs) to the spread of ovarian tumors.

METHODS

Mice were inoculated with patient tumor samples, and developed ovarian tumors over a 16-week period with metastasis occurring in some mice. Species-specific quantitative RT-PCR was used to identify the source of tumor-associated MMPs.

RESULTS

Membrane-type (MT)1-MMP mRNA was significantly increased in high-grade tumors, tumors with evidence of serosal involvement, and tumors in which distant metastases were detected. The increase in MT1-MMP expression was predominantly from the human tumor cells, with a minor contribution from the mouse ovarian stroma. Neither human nor mouse MT2-MMP were correlated with tumor progression and MT3-MMP levels were negligible. While tumor cells did not produce significant amounts of MMP-2 or MMP-9, the presence of tumor was associated with increased levels of MMP-2 expression by mouse ovarian stroma. Stromal-derived MT1-MMP was greater in large tumors and was associated with stromal MMP-2 expression but neither was significantly linked with metastasis.

CONCLUSIONS

These studies indicate that tumor-derived MT1-MMP, more so than other gelatinolytic MMPs, is strongly linked to aggressive tumor behavior. This orthotopic model of human ovarian carcinoma is appropriate for studying ovarian tumor progression, and will be valuable in the further investigation of the metastatic process.

Prostaglandin E2 enhances pancreatic cancer invasiveness through an Ets-1-dependent induction of matrix metalloproteinase-2

Accumulating evidence suggests an important role for cyclooxygenase-2 (COX-2) in the pathogenesis of a wide range of malignancies. Here we tested the hypothesis that the COX-2 product prostaglandin E(2) (PGE(2)) increases cellular invasive potential by inducing matrix metalloproteinase-2 (MMP-2) expression and activity through an extracellular signal-regulated kinase (ERK)/Ets-1-dependent mechanism in pancreatic cancer. PANC-1 and MIAPaCa-2 pancreatic cancer cells were treated with PGE(2) or rofecoxib, a selective COX-2 inhibitor. MMP-2 expression and activity were assayed using Western blot analysis and zymography, respectively. MMP-2 promoter activity was analyzed with a luciferase-based assay. Ets-1 activity was analyzed using gel shift assay. Ets-1 expression was specifically silenced using RNA interference. Cellular invasive and migratory potentials were determined using a Boyden chamber assay with or without Matrigel, respectively. Exogenous PGE(2) induced MMP-2 expression and activity and increased ERK1/2 phosphorylation, Ets-1 binding activity, and MMP-2 promoter activity. PGE(2) also increased cellular migratory and invasive potentials. The mitogen-activated protein kinase kinase inhibitor PD98059 and Ets-1 silencing each abolished PGE(2)-induced increases in MMP-2 expression. PD98059 and Ets-1 silencing each abrogated the effect of PGE(2) on cellular invasive potential but not on cellular migratory potential. Rofecoxib suppressed MMP-2 expression and activity, Ets-1 binding activity, MMP-2 promoter activity, and cellular migratory and invasive potentials. These results suggest that PGE(2) mediates pancreatic cancer cellular invasiveness through an ERK/Ets-1-dependent induction of MMP-2 expression and activity. They also suggest that COX-2 inhibition may represent a strategy to inhibit invasive potential in pancreatic cancer.

The clinical role of the PEA3 transcription factor in ovarian and breast carcinoma in effusions

Ets transcription factors play a central role in invasion and metastasis through regulation of synthesis of proteolytic enzymes and angiogenic molecules. The objective of this study was to investigate the role of PEA3 in tumor progression of ovarian and breast carcinoma metastatic to effusions, and to evaluate the expression of Ets-2 and Erg in ovarian carcinoma. Ovarian (83 malignant effusions, 102 corresponding solid lesions) and breast (33 malignant effusions, 40 corresponding solid lesions) carcinomas were evaluated for expression of PEA3 using mRNA in situ Hybridization (ISH). Expression of Ets-2 and Erg mRNA was analyzed in 50 ovarian carcinoma effusions using the same method. PEA3 mRNA expression was comparable at all sites in ovarian carcinoma (44 out of 83; 53% of effusions, 48 out of 102; 47% of solid tumors). PEA3 mRNA expression in effusions correlated with mRNA expression of the previously studied alphav (P = 0.022), alpha6 (P < 0.001) and beta1 (P < 0.001) integrin subunits, the matrix metalloproteinase (MMP) inducer EMMPRIN (P = 0.015) and interleukin-8 (IL-8) (P = 0.033). Erg and Ets-2 mRNA was expressed in 15 out of 50 (30%) and 18 out of 50 (36%) effusions, respectively, and co-localized with PEA3 (P = 0.017 for Erg, P = 0.004 for Ets-2). In breast carcinoma, PEA3 expression was seen in 19/40 (48%) of solid lesions, with a significant upregulation in corresponding effusions compared to primary tumors (24 out of 33; 73%, P = 0.038). PEA3 mRNA expression in effusions obtained prior to the institution of chemotherapy predicted significantly shorter overall survival in univariate analysis (24 vs 37 months, P = 0.03), with a similar trend for Erg (13 vs 30 months, P = 0.1). In conclusion, PEA3 is expressed at all anatomic sites in serous ovarian cancer and co-localizes with Erg, Ets-2 and several metastasis-associated molecules. PEA3 mRNA expression is a novel marker for tumor progression to malignant effusion in breast carcinoma, and predicts poor outcome in effusions sampled prior to therapeutic intervention in ovarian carcinoma. These findings support a biological role for Ets transcription factors in these malignancies and suggests that they may be targets for therapeutic intervention.

E1AF/PEA3 reduces the invasiveness of SiHa cervical cancer cells by activating serine proteinase inhibitor squamous cell carcinoma antigen

E1AF/PEA3, a member of the Ets family of transcription factors, is associated with the malignant characteristics of cancer cells. The initial aim of our study was to test whether the invasiveness of SiHa cervical cancer cells could be diminished by transfection with antisense E1AF. Using an in vitro invasion assay in which cells penetrate a layer of Matrigel, we found that this was not the case; indeed, the invasiveness of the transfectants was enhanced. To better understand the mechanism of this enhancement, we used the cDNA microarray technique to search for genes whose expression was altered in the antisense E1AF-transfected SiHa cells. Among several genes affected, we found that expression of squamous cell carcinoma antigen (SCCA), a member of the ovalbumin serine proteinase inhibitor family, was significantly reduced. Forced expression of E1AF enabled activation of SCCA expression, and Luciferase reporter assays revealed that E1AF activates the SCCA promoter. Introduction of antisense SCCA into SiHa cells inhibited production of SCCA protein and markedly increased the invasiveness of the cells. Taken together, these results suggest that E1AF suppresses the invasiveness of SiHa cervical cancer cells through transcriptional activation of the SCCA serine proteinase inhibitor gene.

Pathogenesis of pterygia: role of cytokines, growth factors, and matrix metalloproteinases

Pterygium is a common ocular surface disease apparently only observed in humans. Chronic UV exposure is a widely accepted aetiological factor in the pathogenesis of this disease and this concept is supported by epidemiological data, ray tracing models and histopathological changes that share common features with UV damaged skin. The mechanism(s) of pterygium formation is incompletely understood. Recent data have provided evidence implicating a genetic component, anti-apoptotic mechanisms, cytokines, growth factors, extracellular matrix remodelling (through the actions of matrix metalloproteinases), immunological mechanisms and viral infections in the pathogenesis of this disease. In this review, the current knowledge on pterygium pathogenesis is summarised, highlighting recent developments. In addition, we provide novel data further demonstrating the complexity of this intriguing disease.

Restoration of SMAD4 by gene therapy reverses the invasive phenotype in pancreatic adenocarcinoma cells

SMAD4 is a critical cofactor in signal transduction pathways activated in response to transforming growth factor-beta (TGF-beta)-related ligands, regulating cell growth and differentiation. The roles played by SMAD4 inactivation in tumours highlighted it as a tumour-suppressor gene. However, restoration of the TGF-beta antiproliferative pathway following SMAD4 gene transfer in null-tumour cell lines is controversial. Herein, we report the inhibitory effects of SMAD4 on pancreatic tumour invasion and angiogenesis. Adenoviral transfer of this gene in a panel of SMAD4 homozygous-deleted human pancreatic tumour cell lines restored SMAD4 protein expression and function. Although it did not affect proliferation significantly in vitro, SMAD4 inhibited in vivo tumour growth in immunodeficient mice. In this xenograft setting, differential suppression of tumour growth in vivo was mediated, at least in part, through downregulation of vascular endothelial growth factor and expression of gelatinases. We documented the reduced invasion and angiogenesis histologically and by intravital microscopy, and gained mechanistic insight at the messenger and protein level. Finally, we found a negative reciprocal regulation between SMAD4 and ETS-1. ETS-1 is considered a marker for tumour invasion. Upon SMAD4 deletion, we detected high expression levels of ETS-1 in pancreatic tumour cells, suggesting the shift of the pancreatic tumour toward an invasive phenotype.

Ets 1 is expressed in capillary blood vessels but not in lymphatics

Little is known about the mechanisms that regulate lymphangiogenesis and, in particular, about regulation at the transcriptional level. To determine whether parallels exist in the mechanisms of angiogenesis and lymphangiogenesis, the expression of the Ets 1 transcription factor (which has previously been shown to be involved in angiogenesis) was examined in two transgenic mouse lines, namely RipVEGF-C mice (which develop lymphatic capillaries ectopically around islets of Langerhans) and Rip1Tag2 mice (which develop insulinomas that are not lymphangiogenic). Crossing the two lines results in double transgenic mice that develop lymphatics around insulinomas, which in turn promotes metastasis to regional lymph nodes. By immunohistochemistry, it was found that, in contrast to blood vessels, lymphatic vessels in wild-type and transgenic mice did not express Ets 1. Immunohistochemical staining for matrix metalloproteinase (MMP)-2 and MMP-9 as well as membrane type 1-MMP (MT1-MMP/MMP-14), all of which are encoded by known or potential Ets 1 target genes, showed the same cellular distribution as Ets 1. These findings suggest that the transcriptional regulatory mechanisms of lymphangiogenesis differ from those involved in angiogenesis. Furthermore, if proteases are involved in lymphangiogenesis, these observations suggest that they are different from those considered to be important for blood vessel formation.

Association of ets-related transcriptional factor E1AF expression with tumour progression and overexpression of MMP-1 and matrilysin in human colorectal cancer

Expression of E1AF/PEA3 (ETV4), an ets family transcription factor, has been implicated in the invasive potential of several cancer cell lines through induction of matrix metalloproteinase (MMP) expression. The aim of this study was to examine E1AF mRNA expression and to determine whether it is correlated with progression of, and/or MMP expression in, human colorectal cancer. Using the semi-quantitative reverse transcriptase-polymerase chain reaction (RT-PCR), 100 colorectal cancer tissues were analysed for E1AF mRNA expression. Expression of ER81 (ETV1) and ERM (ETV5), the other two members of the PEA3 subfamily, and Ets-1 and Ets-2 was also analysed. The results were correlated with clinicopathological characteristics and MMP expression. Immunohistochemical analysis and an in vitro invasion assay were also performed. E1AF mRNA expression was detected in 62% of the 100 colorectal cancer tissues, but was undetectable or only faintly detected in adjacent non-tumour tissues. E1AF mRNA was detected in all of the ten liver metastases from colorectal cancers. E1AF expression correlated significantly with depth of invasion, lymphatic and venous invasion, lymph node and distant metastasis, advance in pathological tumour-node-metastasis stage, and recurrence. Patients with E1AF-positive tumours had significantly shorter overall and disease-free survival periods than did those with E1AF-negative tumours (p < 0.0001 and p < 0.0001, respectively). E1AF expression retained its significant predictive value for overall and disease-free survival in multivariate analysis that included conventional clinicopathological factors (p = 0.0066 and p = 0.0109, respectively). Among the MMPs analysed, expression of MMP-1 and matrilysin correlated significantly with E1AF expression. In contrast, expression of ER81 and ERM did not correlate with clinicopathological characteristics or the expression of these MMPs. Immunohistochemical expression of E1AF was predominantly observed at the invasive front, where the expression of MMP-1 and matrilysin and nuclear beta-catenin expression were often co-localized. Antisense E1AF-transfected HT-29 colon cancer cells expressed reduced levels of MMP-1 and matrilysin and were less invasive in vitro than neo-transfected HT-29 cells. The results of this study suggest that E1AF, the expression of which is closely correlated with the expression of MMP-1 and matrilysin, plays a key role in the progression of colorectal cancer.

Acceleration of invasive activity via matrix metalloproteinases by transfection of the estrogen receptor-alpha gene in endometrial carcinoma cells

It is well known that the functions of reproductive organs are regulated by sex steroids and their receptors and it is hypothesized that the progression of neoplasms that originate from the reproductive organs is influenced by them. However, the correlation between sex steroids and tumor progression, especially tumor invasion, is not well known in endometrial carcinoma. In our study, we focused on the influence of estrogen and its receptor in invasion and matrix metalloproteinases (MMPs), which are known to be important in tumor invasion, as well as on endometrial carcinoma cells. The growth of Ishikawa cells, to which an estrogen receptor-alpha expressing vector was transfected, was accelerated by 17 beta-estradiol as was the acceleration of the expression of cyclin D1. By invasion assay, in conditions with 17 beta-estradiol, the invasiveness of Ishikawa cells was enhanced. Furthermore, according to the accelerated invasiveness, the expression of MMP-1, -7 and -9 and Ets-1 was enhanced. These results suggest that activation of ER-alpha by estrogen results in tumor progression by stimulating cell growth and invasiveness via acceleration of the expression of MMPs.

Expression of vascular endothelial growth factor and E-cadherin in human ovarian cancer: association with ascites fluid accumulation and peritoneal dissemination in mouse ascites model

Ascites formation and peritoneal dissemination are critical problems in patients with advanced ovarian cancer. Vascular endothelial growth factor (VEGF), also known as angiogenic growth factor, is a potent mediator of peritoneal fluid accumulation and angiogenesis of tumors. E-Cadherin is an adhesion molecule that is important for cell-to-cell interaction. To elucidate the molecular mechanism of ascites formation and peritoneal dissemination of ovarian cancer, we examined the expression of VEGF and E-cadherin in different ovarian cancer cell lines and utilized nude mice to compare the biological characteristics of ovarian cancer cells. Three human ovarian cancer cell lines (AMOC-2, HNOA and HTBOA) were used in this study. Expression of genes was analyzed by northern blotting and RT-PCR methods. AMOC-2 expressed E-cadherin, but not VEGF. HNOA expressed VEGF without E-cadherin expression. HTBOA expressed both VEGF and E-cadherin. Each human ovarian cancer model revealed a specific feature. The AMOC-2 mouse had a single large peritoneal tumor without ascites or remarkable peritoneal dissemination. HTBOA and HNOA mice had bloody ascites and marked peritoneal dissemination. Introduction of VEGF antisense into HTBOA cells could inhibit the ascites formation. It is suggested that VEGF is important for the ascites formation via the increased vascular permeability effect. The deregulation of E-cadherin expression might be involved in the peritoneal dissemination. These molecules are important for the formation of specific features of advanced ovarian cancer. Ovarian cancer cell lines that had different gene expression patterns produced nude mouse human ovarian cancer models with different characteristics.

Anti-invasive effect of MMI-166, a new selective matrix metalloproteinase inhibitor, in cervical carcinoma cell lines

OBJECTIVES

The aim of our study was to evaluate the anti-invasive effect of MMI-166, a new matrix metalloproteinase (MMP) inhibitor in cervical carcinoma cell lines.

METHODS

We analyzed the invasive activities of cervical carcinoma cell lines (CAC-1, CaSki, and SiHa) and the gene expression of various matrix proteinases (matrix metalloproteinase-1 [MMP-1], MMP-2, MMP-9, membrane-type MMP type 1 [MT1-MMP], MT2-MMP, and MT3-MMP) and their inhibitors (tissue inhibitor of metalloproteinase type 1 [TIMP-1] and TIMP-2). The effect of MMI-166 was analyzed by in vitro invasion assay. The cytotoxicity of MMI-166 was determined by MTT assay. The gelatinase activity was analyzed by gelatin zymography.

RESULTS

Cervical carcinoma cell lines, which produced both MMP-2 and MT1-MMP, showed invasive capacity in the in vitro invasion assay. The invasion of cervical carcinoma cells was suppressed by MMI-166. No remarkable suppression of the proliferation by MMI-166 was observed in the MTT assay. Gelatin zymography revealed complete suppression of MMP-2 activity by MMI-166.

CONCLUSIONS

MMI-166 inhibited the MMP-2 activity in cervical carcinoma cells and it is useful for the regulation of cervical carcinoma cell invasion.