Characterization of extracellular matrix-degrading proteinase and its inhibitor in gynecologic cancer tissues with clinically different metastatic form

Changes in the expression of cancer- and metastasis-related genes and proteins after metformin treatment under different metabolic conditions in endometrial cancer cells

Research question

Hyperinsulinemia and elevated estrogen levels are known risk factors for endometrial cancer (EC) development and are associated with obesity, type 2 diabetes mellitus (T2DM), insulin resistance, among others. Metformin, an insulin-sensitizing drug, displays anti-tumor effects in cancer patients, including EC, but the mechanism of action is still not completely understood. In the present study, the effects of metformin on gene and protein expression were investigated in pre- and postmenopausal EC in vitro models in order to identify candidates that are potentially involved in the drug's anti-cancer mechanism.

Design

After treating the cells with metformin (0.1 and 1.0 mmol/L), changes in the expression of >160 cancer- and metastasis-related gene transcripts were evaluated with RNA arrays. A total of 19 genes and 7 proteins were selected for a follow-up expression analysis, including further treatment conditions, in order to evaluate the influence of hyperinsulinemia and hyperglycemia on metformin-induced effects.

Results

Changes in the expression of BCL2L11, CDH1, CDKN1A, COL1A1, PTEN, MMP9 and TIMP2 were analyzed on gene and protein level. The consequences resulting from the detected expression changes as well as the influence of varying environmental influences are discussed in detail. With the presented data, we contribute to a better understanding of the direct anti-cancer activity of metformin as well as its underlying mechanism of action in EC cells.

Conclusions

Although further research will be necessary to confirm the data, the influence of different environmental settings on metformin-induced effects could be highlighted with the presented data. Additionally, gene and protein regulation were not similar in the pre- and postmenopausal in vitro models.

The protective role of the -1306C>T functional polymorphism in matrix metalloproteinase-2 gene is associated with cervical cancer: implication of human papillomavirus infection

Cervical cancer is the major reproductive health problem among women caused by persistent infection of high-risk human papillomavirus (HR-HPV). Metalloproteinase-2 (MMP-2) is an endopeptidase highly expressed in cervical cancer; however, the genetic link between aberrant expression of MMP-2 and cervical carcinogenesis is not known. The genotypic distribution, expression pattern of MMP-2 and HPV infection, was analyzed in a total of 300 fresh surgically resected cervical tissue biopsies. The MMP-2 C1306T (rs243865) promoter polymorphism dominant model (CC v/s CT + CT + TT) revealed that the CC genotype had a 4.33-fold significant increased risk for development of cervical cancer (OR = 4.33; 95 % CI = 2.36-4.02, p = 0.0001) compared to those with variant genotypes (-1306 CT + TT). The C allele was associated with 3-fold significant increased risk (OR = 2.95; 95 % CI = 1.90-4.60, p = 0.0002) compared to T allele. Interestingly, a significant correlation was found between high expression of MMP-2 protein and CC genotype in cancer patients (p = 0.001) compared to normal controls (p = 0.012). Further analysis showed that the risk of cancer was extremely pronounced in HPV positive patients (OR = 9.33; 95 % CI = 2.88-30.20, p = 0.0001) compared to HPV negative ones, implicating the possible interaction between -1306CC genotype and HPV infection in increasing the cancer risk (p = 0.0001). The leads from the present study suggest the protective role of gene variant -1306C>T at the promoter region of the MMP-2 against HPV-mediated cervical cancer. These findings substantiate the functional role of MMP-2 C1306T polymorphism in a significant downregulation of MMP-2 protein in women with variant genotype (CT/TT) compared to the normal wild CC genotype.

Combination of strong MMP-2 and weak TIMP-2 immunostainings is a significant prognostic factor in endometrial carcinoma

Objective. The aim of this study was to evaluate the combined effects of MMP-2 and TIMP-2 protein immunoreactivities on the prognosis in endometrial carcinoma. Methods. Paraffin-embedded tissue samples from 225 primary endometrioid adenocarcinomas and 13 histologies other than endometrioid adenocarcinoma were immunohistochemically stained for MMP-2 and TIMP-2. Results. In Kaplan-Meier analysis, the 5-year cancer-specific survival rate of the endometrioid adenocarcinoma patients with negative MMP-2 and positive TIMP-2 staining was 100%, whereas only 78% of patients presenting with positive MMP-2 and negative TIMP-2 staining results were alive at that time. In Cox regression analysis, patients with positive MMP-2 and negative TIMP-2 immunostaining had a 4.7-fold relative risk of death from endometrial carcinoma compared to the group of patients with negative MMP-2 and positive or negative TIMP-2 immunoreaction. Conclusions. MMP-2 seems to be the main metalloproteinase determining the prognosis in endometrial carcinoma. Combination of strong MMP-2 and weak TIMP-2 immunostainings was the most potent prognostic marker for poor survival.

Interleukin-6 signaling regulates anchorage-independent growth, proliferation, adhesion and invasion in human ovarian cancer cells

It has been widely reported that Interleukin-6 (IL-6) is overexpressed in the serum and ascites of ovarian cancer (OVCA) patients, and elevated IL-6 level correlates with poor prognosis and survival. However, the exact role that IL-6 plays in this malignancy or whether IL-6 can regulate tumorigenic properties has not been established. Here we demonstrate that overexpression of IL-6 in non-IL-6-expressing A2780 cells (by transfecting with plasmid encoding for sense IL-6) increases anchorage-independent growth, proliferation, adhesion and invasion, while depletion of endogenous IL-6 expression in IL-6-overexpressing SKOV-3 cells (by transfecting with plasmid encoding for antisense IL-6) decreases. Further investigation indicates that IL-6 promotes OVCA cell proliferation by altering cell cycle distribution rather than inhibiting apoptosis and that IL-6-enhanced OVCA cell invasive may be associated with increased matrix metalloproteinase (MMP)-9 but not MMP-2 proteolytic activity. In addition, overexpressing or deleting of IL-6 in OVCA cells enhances or reduces its receptor (IL-6Rα and gp130) expression and basal phosphorylation levels of both ERK and Akt, and additional treatment with specific inhibitor of the ERK or Akt signaling pathway significantly inhibits the proliferation of IL-6-overexpressing A2780 cells. Our data suggest that the autocrine production of IL-6 by OVCA cells regulates tumorigenic properties of these cells by inducing IL-6 signaling pathways. Thus, regulation of IL-6 expression or its related signaling pathway may be a promising strategy for controlling the progression of OVCA.

Immunoreactivity for TIMP-2 is associated with a favorable prognosis in endometrial carcinoma

Tissue inhibitors of metalloproteinases are important regulators of metalloproteinase activity, and the balance of active enzyme and inhibitor is a critical determinant of tumor cell invasiveness. This study aimed to evaluate the prognostic and clinical implications of the two main inhibitors of matrix metalloproteinases, TIMP-1 and TIMP-2, in endometrial carcinoma. The material consisted of 241 patients with primary endometrial carcinoma. The median follow-up time was 77 months. Expressions of TIMP-1 and TIMP-2 proteins were examined in paraffin-embedded tumor sections by immunohistochemical methods. Positive staining for TIMP-1 and -2 was observed in 88% and 86% of the primary tumors, respectively. The Kaplan-Meier analysis showed that the 5-year cancer-specific survival rate of the patients with TIMP-2 positive immunostaining was 89% and that of the TIMP-2 negative patients 78%. Positive immunoreaction for TIMP-2 correlated with favorable cancer-specific and overall survival. When including only endometrioid adenocarcinomas, a similar trend towards favorable survival was seen. Excluding stage IA carcinomas, the difference became again statistically significant. For TIMP-1, there was no statistically significant association with overall or cancer-specific survival. The Cox regression analysis showed stage, grade and TIMP-2 to be significant predictors of survival. We suggest that TIMP-2 may have a more important role in endometrial carcinoma progression than TIMP-1 and might serve as a potential marker for favorable prognosis in this type of cancer.

Expression of ADAM9 in CIN3 lesions and squamous cell carcinomas of the cervix

OBJECTIVE

ADAM9 is a member of the ADAM family which is involved in cellular processes like cell adhesion, migration and signalling [M.L. Moss, J.M. White, M.H. Lambert, R.C. Andrews, TACE and other ADAM proteases as targets for drug discovery. Drug Discov. Today 2001; 6:417-426., G. Murphy, The ADAMS: signalling scissors in the tumour microenvironment. Nat. Cancer Rev. 2008; 8:929-941.]. ADAM9 overexpression has been described in many of solid tumours including prostate, renal, pancreas, lung and gastric cancer [R.J. Grutzmann, J. Luttges, B. Sipos, O. Ammerpohl, F. Dobrowolski, I. Alldinger, et al., ADAM9 expression in pancreatic cancer is associated with tumour type and is a prognostic factor in ductal adenocarcinoma. Br. J. Cancer 2004; 90:1053-1058., C.A. Iacobuzio-Donahue, A. Maitra, M. Olsen, A.W. Lowe, N.T. van Heek, C. Rosty, et al., Exploration of global gene expression patterns in pancreatic adenocarcinoma using cDNA microarrays. Am. J. Pathol. 2003; 162: 1151-1162., Y. Shintani, S. Higashiyama, M. Ohta, H. Hirabayashi, S. Yamamoto,T. Yoshimasu, et al., Overexpression of ADAM9 in non-small cell lung cancer correlates with brain metastasis. Cancer Res. 2004; 64:4190-4196., S. Carl-McGrath, U. Lendeckel, M. Ebert, A. Roessner, C. Rocken, The disintegrin-metalloproteinases ADAM9, ADAM12, and ADAM15 are upregulated in gastric cancer. Int. J. Oncol. 2005; 26:17-24., F.R. Fritzsche, K. Wassermann, M. Jung, A. Tölle, I. Kristiansen, M. Lein, et al., ADAM9 is highly expressed in renal cell cancer and is associated with tumour progression. BMC Cancer 2008; 8:179.]. The involvement of this protease in cervical carcinogenesis has not been yet investigated. The aim of this study was to evaluate the expression of ADAM9 in normal epithelium, CIN3 lesions and squamous cell carcinomas (SCC) of the uterine cervix.

METHODS

Archived paraffin-embedded tissue blocks from biopsy or surgery specimens obtained from 50 subjects with CIN3 and squamous cancer of the cervix were studied by immunohistochemistry using heat-induced epitope retrieval for ADAM9 expression.

RESULTS

Weak expression of ADAM9 was found in the normal cervical epithelium with weak cytoplasmatic staining but also membrane immunoreactivity. Evident staining for ADAM9 was detected in 31 out of 36 (86%) CIN3 lesions and in 13 out of 14 (93%) squamous cell carcinomas of the uterine cervix. Staining was stronger in SCC compared to CIN3 lesions. Moderate staining was detected in 64% (9/14) of SCC and in 36% (13/36) CIN3 lesions. Weak staining was observed in 50% (18/36) of CIN3 lesions and in 29% (4/14) of SCC. The difference in the ADAM9 protein expression between cervical squamous carcinomas and normal epithelium was highly significant. Statistical significance was also found for the increased expression observed in CIN3 lesions versus normal squamous epithelium.

CONCLUSIONS

Our results show for the first time, that ADAM9 expression is low in the squamous epithelium of the cervix, but is increased in CIN3 lesions as well as SCCs being the increase in both cases statistically significant.

Synergistic effects of epidermal growth factor and hepatocyte growth factor on human ovarian cancer cell invasion and migration: role of extracellular signal-regulated kinase 1/2 and p38 mitogen-activated protein kinase

Ovarian cancer is the primary cause of death from gynecological malignancies with a poor prognosis characterized by widespread peritoneal dissemination. However, mechanisms of invasion and metastasis in ovarian cancer remain poorly understood. Epidermal growth factor (EGF) and hepatocyte growth factor (HGF) are often both overexpressed and contribute to the growth of ovarian cancer by activating autocrine pathways. In the present study, we investigated the mechanisms of invasive activity of EGF, HGF, and their synergistic effects in human ovarian cancer cells. Here our data suggest that EGF and HGF may use unique and overlapping signaling cascades leading to the invasive phenotype. We revealed that HGF-mediated cell migration and invasion required the coordinate activation of the phosphatidylinositol 3-kinase/Akt and extracellular signal-regulated kinase 1/2. Although EGF-dependent invasive phenotype appeared to have similar requirements for phosphatidylinositol 3-kinase, this growth factor used the alternative p38 MAPK pathway for cell invasion. A significant role of p38 MAPK was further supported by the observation that expression of dominant negative p38 MAPK likewise inhibited EGF-dependent invasiveness and cell motility. We also showed that EGF cooperated with HGF to promote a highly invasive phenotype via the increased secretion of matrix metalloproteinase (MMP)-9. The coincident induction of MMP-9 was functionally significant because inclusion of MMP-9 inhibitor or an anti-MMP-9 neutralizing antibody abolished EGF- and HGF-induced cellular invasion. These findings provide insights into the mechanism of the malignant progression of ovarian cancer.

Apparent suppression of MMP-9 activity by GD1a as determined by gelatin zymography

Gelatin zymography is widely used to detect and evaluate matrix metalloproteinase-9 (MMP-9) activity. MMP-9 transcription was previously shown to be negatively regulated by ganglioside GD1a [D. Hu, Z. Man, T. Xuan, P. Wang, T. Takaku, S. Hyuga, X.S. Yao, T. Sato, S. Yamagata, T. Yamagata, Ganglioside GD1a regulation of matrix metalloproteinase-9 (MMP-9) expression in mouse FBJ cell Lines: GD1a suppression of MMP-9 expression stimulated by PI3K-Akt and p38 though not by the Erk signaling pathway, 2006, submitted for publication.]. Zymography of MMP-9 of FBJ-M5 cells preincubated with GD1a indicated a greater decrease in activity than expected from mRNA suppression. Incubation of conditioned medium containing MMP-9 with GD1a caused MMP-9 activity to decrease. Examination was thus made to confirm that MMP-9 activity is actually suppressed and/or MMP-9 protein undergoes degradation by GD1a. GD1a was found to have no effect on MMP-9 activity and Western blots indicated GD1a not to diminish MMP-9 during electrophoresis under reducing conditions. GD1a appeared to mediate the binding of a portion of MMP-9 with certain molecules, with consequently greater molecular mass on the gel, to cause decrease in the activity of MMP-9 at the site where it would normally appear. Caution should be used in doing gelatin zymography since molecules other than GD1a may similarly work, causing decrease in MMP-9 activity in zymography.

Endometrial tumor invasiveness is related to metalloproteinase 2 and tissue inhibitor of metalloproteinase 2 expressions

Matrix metalloproteinase (MMPs) expression has been linked to gynecological tumor aggressiveness. The objective of this study was to determine MMP-2, MMP-7, and MMP-9 and tissue inhibitors of metalloproteinases (TIMP)-1 and TIMP-2 expression in endometrial malignancies and their relation to clinical and histologic parameters. Formalin-fixed, paraffin-embedded tumor samples from 50 patients with endometrial carcinoma treated between 1999 and 2004 were stained with specific monoclonal antibodies. The tumors were grouped according to the FIGO classification. The staining results were compared to histologic and clinical data. Semiquantitative analysis of MMP and TIMP expression showed a significant difference in TIMP-2 expression according to the histologic subtype (P = 0.03) and also a trend towards a difference in MMP-9 expression (P = 0.05). MMP-2 expression increased and TIMP-2 expression fell as the histologic grade increased (P = 0.0007, P < 0.0001, respectively). MMP-2 expression correlated with lymph node metastasis (P = 0.04), while TIMP-2 expression correlated with the depth of myometrial invasion (P = 0.01), vasculolymphatic space involvement (P = 0.02), and lymph node metastasis (P = 0.0003). These results support the involvement of MMPs and TIMPs in endometrial tumor growth and progression. High MMP-2 and low TIMP-2 expression were the most potent markers of endometrial tumors with a high risk of local and distant spread.

Inhibition of matrix metalloproteinase-2 secretion and invasion by human ovarian cancer cell line SK-OV-3 with lysine, proline, arginine, ascorbic acid and green tea extract

AIMS

Based on the poor prognosis associated with ovarian cancer and reported anticancer properties of specific nutrients, we investigated the effect of a nutrient mixture (NM) containing lysine, proline, arginine, ascorbic acid and epigallocatechin gallate on human ovarian cancer cells SK-OV-3 by measuring: cell proliferation, modulation of matrix metalloproteinase (MMP)-2 and -9 expression, and cancer cell invasive potential.

METHODS

Cell proliferation was evaluated by MTT assay, MMP activity by gelatinase zymography, and invasion through Matrigel.

RESULTS

Human ovarian cancer cell growth was not significantly affected by the NM. Zymography demonstrated inhibition of MMP-2 secretion in a dose-dependent fashion with virtual total inhibition at 50 microg/mL NM concentration. Invasion of human ovarian cancer cells through Matrigel decreased in a dose-dependent fashion, with 90% inhibition at 500 microg/mL NM and 100% inhibition at 1000 microg/mL NM (P < 0.0001).

CONCLUSION

The combination of lysine, proline, arginine, ascorbic acid and green tea extract tested inhibited critical steps in cancer development and spread, such as MMP expression and invasion, indicating its potential as a treatment modality against ovarian cancer.

Metalloproteinase-2, -7 and -9 and tissue inhibitor of metalloproteinase-1 and -2 expression in normal, hyperplastic and neoplastic endometrium: a clinical-pathological correlation study

BACKGROUND

Matrix metalloproteinases (MMPs) and their inhibitors are key-players in extracellular matrix and basement membrane degradation, and are involved in both physiological and malignant processes. The aim of this study was to examine MMP-2, -7 and -9 and TIMP-1 and -2 expression in normal, hyperplastic and malignant endometrium, and their relation to clinical and histological prognostic factors.

MATERIALS AND METHODS

We performed qualitative and semi-quantitative immunohistochemical analysis of 20 samples of normal endometrium (10 in the proliferative phase, 10 in the secretory phase), 39 samples of hyperplastic endometrium (17 without atypia and 22 with atypia) and 38 samples of endometrioid carcinoma, by using specific monoclonal antibodies.

RESULTS

In normal endometrium, epithelial expression of MMP-2 (P = 0.0007), MMP-7 (P = 0.0002) and TIMP-2 (P = 0.0004) was increased during the proliferative phase of the menstrual cycle. MMP-2 expression correlated negatively with TIMP-2 expression (P = 0.001, rho = 0.702). Endometrial stromal cells in the secretory phase showed strong MMP-2 expression (P = 0.004) and weak MMP-7 (P = 0.001) and TIMP-1 expression (P = 0.01). In hyperplastic endometrium, the presence of atypia was associated with lower TIMP-2 expression (P = 0.005) and was also associated with a trend towards higher MMP-2 expression. Endometrial stromal cell expression of MMP-2, -7 and -9 and TIMP-1 and -2 did not differ between hyperplastic endometrium with and without atypia. A gradient of MMP-2 and -9 expression was observed from hyperplastic endometrium to endometrial carcinomas. In endometrial carcinomas, MMP-2 expression increased (P = 0.0004) and TIMP-2 expression decreased (P = 0.0005) with the histological grade. TIMP-2 expression correlated with myometrial invasion (P = 0.005), lymphovascular space involvement (P = 0.008) and lymph node involvement (P = 0.007).

CONCLUSION

These results support the involvement of MMPs and TIMPs in endometrial carcinogenesis. Strong MMP-2 and weak TIMP-2 expression were the most potent markers of endometrial malignancies with a high risk of local and distant spread.

Matrix metalloproteinase 1 gene polymorphism as a prognostic predictor of invasive cervical cancer

OBJECTIVES

Whereas human papillomavirus (HPV) infection is the major determinant of cervical carcinogenesis, host genetic factors may confer individual susceptibility and prognosis. Matrix metalloproteinase 1 (MMP-1) is an important modulator of carcinogenesis. A guanine insertion (2G) polymorphism at nucleotide -1607 of the MMP-1 gene promoter creates an Ets-1-binding site, which increases transcription activity. The present study investigates the association between MMP-1 polymorphism and cervical neoplasia, and their prognostic significance.

METHODS

In this study, the MMP-1 polymorphism was assessed in 135 high-grade squamous intraepithelial lesions (HSILs) and 197 invasive squamous cell carcinomas (SCCs), and in age-matched controls, by capillary electrophoresis. The association of clinicopathological factors and HPV status with MMP-1 genotypes was tested.

RESULTS

Frequencies of the 2G allele in HSIL and SCC were 64% and 65%, respectively, which did not differ significantly from control values (66% and 64%, respectively). The 2G allele was associated with advanced stages of disease (P = 0.03), whereas the G allele was more common in patients with regional lymph node metastases (P = 0.02). The survival time in patients with the heterozygous genotype G/2G (median, 55.3 months) was significantly longer than those with either the G/G (50.3 months) or 2G/2G genotype (43.9 months) (P = 0.02). No significant correlation between HPV status and MMP-1 genotype was identified.

CONCLUSIONS

The genetic polymorphisms of MMP-1 are not associated with the risk of HSIL and SCC, but with the invasiveness and prognosis of SCC. The heterozygous genotype of MMP-1 can be used as a prognostic marker in patients with invasive cervical cancer.

Three-dimensional coculture of endometrial cancer cells and fibroblasts in human placenta derived collagen sponges and expression matrix metalloproteinases in these cells

OBJECTIVE

Collagen gel constitutes a valuable tool for the study of cell-matrix interactions; however, it is sometimes difficult to use the gel, in which tumor and stromal cells are cocultured, for immunohistochemistry, because it is easily broken during the process of fixation and embedding in paraffin, especially after long-term culture.

METHODS

To examine the interaction between endometrial cancer cells and fibroblasts in tumor invasion, we carried out three-dimensional (3-D) coculture of various endometrial cancer cell lines and fibroblasts in human placenta derived collagen sponges and analyzed the expression and localization of matrix metalloproteinases (MMP) and plasminogen activators (PA) in these cells by immunohistochemistry.

RESULTS

After 4 weeks of culture on the collagen sponges, endometrial cancer cells composed stratiform or glandular structures on the layer of extracellular matrix, which was composed from fibloblasts and extracellular matrix. Compared to Ishikawa cells, which were rarely invasive, HEC-1A and HEC-1BE and cocultured fibroblasts showed high invasiveness and strong expression of some proteins. In cell line HEC-1BE, MMP-1, -7, and -9, MT1-MMP, tissue inhibitors of metalloproteinases 2, and uPA showed intensive staining in both cancer cells and fibroblasts by immunohistochemistry. HEC-1A cells and cocultured fibroblasts showed expression patterns similar to those of HEC-1BE.

CONCLUSION

These results suggested that expression of MMPs and uPA was accelerated in fibroblasts surrounded by cancer cells. We believe that our 3-D coculture system has merit in that the interaction between cancer cells and stromal cells can be visually analyzed by immunohistochemistry and that experiments for a long period, at least 2 weeks, are possible. Furthermore, it is expected that some animal, e.g., nude mouse, experiments can be replaced by experiments using this culture system.

Changes in matrix metalloproteinases and their endogenous inhibitors during tumor progression in the uterine cervix

PURPOSE

To study the role of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) in cervical tumorigenesis, we analyzed 70 cervical tissue specimens that included 15 low-grade squamous intraepithelial lesions (SILs), 20 high-grade SILs, 25 squamous cell carcinomas (SCCs) and 10 specimens of normal cervical tissue.

METHODS

The gelatinolytic activity of MMP-9 and MMP-2 was determined by zymographic analysis. The expression of MMP-9 and MMP-2 and TIMP-1 and TIMP-2 was determined by immunohistochemistry.

RESULTS

All the samples had 72/66 kDa gelatinase activity; 92 kDa gelatinase activity was detected only in high-grade SILs and SCCs. Immunohistochemical analysis showed weak positivity for MMP-2 in normal cervical epithelium and low-grade SILs. However, high-grade SILs and SCCs showed intense cellular and stromal reactivity for MMP-2 and MMP-9. For TIMP-1 and TIMP-2, normal cervical epithelium and low-grade SILs showed intense immunostaining, >50% of high-grade SILs showed positivity, and 95% of SCCs showed intense stromal and cellular reactivity.

CONCLUSIONS

Increase in the relative activity of these gelatinases and enhanced immunostaining for MMPs and TIMPs with tumor progression suggest that they may play a crucial role in cervical cancer progression. A significant association between stage of the lesion and expression of MMPs and TIMPs ( P<0.01) was found. Immunohistochemical studies indicate that these MMPs may be of basal cell origin in cervical tissue, although the mechanism of their upregulation is not clearly understood.

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 matrix metalloproteinases in ovarian endometriomas: immunohistochemical study and enzyme immunoassay

Like carcinoma, endometriosis has the unique characteristics, of invasion and metastasis, though pathologically, it is a benign tumor. However, the mechanism of destruction of the surrounding tissue in endometriosis is still unclear. In this study, the expression and localization of matrix metalloproteinases (MMP)-1, -2, -3, -7, -9 and tissue inhibitors of metalloproteinases-1 (TIMP-1) were evaluated by immunohistochemistry for 20 cases and the amounts of MMP-1, TIMP-1 and MMP-1/TIMP-1 complex in the fluid of endometrioma, were analyzed by ELISA and western blotting for 20 cases, which were analyzed by immunohistochemical study. MMP-1, -2 and -9 were detected strongly in both stromal and epithelial cells and MMP-7 in the epithelial cells in the menstrual period. MMP-3 was mainly expressed in macrophage containing hemosiderin but the change of expression was not clear. TIMP-1 was intensively detected in both stromal and epithelial cells in the menstrual period but the expression decreased in other stages of the menstrual cycle. ELISA for MMP-1 also showed results similar to immunohistochemistry, suggesting that it was released to the cyst in the menstrual period when it was released to the extracellular space from the cytoplasm. The expression of TIMP-1 was not clearly changed during the menstrual cycle. From these results, it was suggested that the destruction of the surrounding matrix by endometriosis might be caused by various MMPs, which are mainly produced in stromal cells.

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.

Angiogenesis in ovarian cancer: molecular pathology and therapeutic strategies

Ovarian cancer claims the lives of more women in North America each year than all other gynecologic malignancies combined. Despite the high initial response rates of patients with advanced ovarian cancer to aggressive primary surgical debulking followed by combination chemotherapy, the majority of patients will ultimately develop disease recurrence. The high risk of relapse and nearly guaranteed incurability after relapse is due to genetic instability and a high mutation rate of neoplastic cells that together allow for a high risk of selection for drug resistance. Given the seemingly insurmountable obstacle that acquired drug resistance presents in a setting of minimal, often undetectable, residual tumor burden in women with ovarian cancer, antiangiogenic-targeted therapies offer an attractive strategy for enhanced long-term disease-free survival. The past decade has witnessed a substantial proliferation in our knowledge regarding tumor angiogenesis, which has spurred interest in antiangiogenesis drug development. Current clinical trials are evaluating these agents in a variety of solid tumors, including ovarian cancer. Preliminary work has provided hope that the addition of antiangiogenic therapies may be incorporated into the treatment of women afflicted with ovarian cancer and may translate into enhanced survival.

Activated matrix metalloproteinase-2--a potential marker of prognosis for epithelial ovarian cancer

OBJECTIVES AND METHODS

To investigate the relationship between the expression of matrix metalloproteinase-2 (MMP-2) and clinical characteristics in patients with epithelial ovarian tumors, we examined the expression of MMP-2 in 26 epithelial benign ovarian tumors (EBOT) and 41 epithelial ovarian carcinomas (EOC) using semi-quantitative reverse transcriptase-polymerase chain reaction and immunohistochemistry. We also analyzed pro-MMP-2 and activated MMP-2 in epithelial ovarian tumors using Western blot. RESULTS The expression levels of MMP-2 mRNA and overall protein were higher in EOC than in EBOT, but the differences were not statistically significant (P > 0.05). MMP-2 mRNA and immunoreactive protein for MMP-2 were not significantly associated with clinicopathological features in EOC. The positive percentages of the active form of MMP-2 were 71% in EOC and 42% in EBOT, respectively (P < 0.05). The positive percentage of the active form of MMP-2 in stage III and IV EOC was significantly higher (81%) than that (33%) in stage I and II EOC (P = 0.01). The expression of activated MMP-2 was significantly related to disease progression in EOC (P = 0.02). The percentages of active MMP-2 in positive immunoreaction tumor cells and fibroblasts were, respectively, 96 and 89%. The difference was not statistically significant (P = 0.54). The positive and negative predictive values of active MMP-2 for disease progression were 65 (19/29) and 75% (9/12), respectively, and the accuracy was 68% (28/41).

CONCLUSION

MMP-2 generally appears in epithelial ovarian tumors and there is a tendency to express more MMP-2, and especially activated MMP-2, in EOC. MMP-2 mRNA and pro-MMP-2 are not associated with the clinicopathological features in patients with EOC. There was a significant relationship between activated MMP-2 and invasiveness, metastasis, and disease progression in EOC and activated MMP-2 is a potential marker of prognosis.

Quantification of matrix metalloproteinase activity in plasma of patients enrolled in a BAY 12-9566 phase I study

The expression of matrix metalloproteinases (MMPs) is often associated with invasiveness or grade of tumours. Increased blood levels of MMP proteins, including MMP-1, MMP-2, MMP-3 and MMP-9 have been detected in various types of cancers. With the exception of one study, MMPs in serum and plasma have been determined using ELISA. In the present study we measured the activity of the MMPs found in human plasma samples using gelatin enzymography and fluorimetric degradation assays. We used plasma samples from healthy control subjects and cancer patients enrolled in a dose-finding study for the MMP inhibitor, BAY 12-9566, to assess the activity of MMPs found in plasma and screen for efficacy of the MMP inhibitor. BAY 12-9566 has inhibitory activity toward MMP-2, MMP-3 and MMP-9. Patients with advanced solid tumours were enrolled in our study and plasma was collected on day 1 before dosing and at steady-state of the drug on day 15. Our results show that BAY 12-9566 was effective in lowering the plasma gelatinolytic activity in the group of 29 patients when considering the data obtained from a fluorimetric gelatinase assay. The data obtained from gelatin enzymography, however, did not reach significance. The fluorimetric degradation assay could be a useful tool to screen plasma from cancer patients in other clinical trials assessing MMP inhibitors.

Angiogenesis in ovarian cancer

Angiogenesis, the formation of new vessels from pre-existing vasculature, is critical to ascites development and metastasis in ovarian cancer. Many growth factors important to ovarian cancer invasion are also prominent in its associated angiogenesis. Deregulation of normal angiogenic processes occurs with the cancer's acquisition of the ability to secrete pro-angiogenic factors. The local imbalance of endogenous angio-stimulators and angio-inhibitors promotes vascularization and vascular leak. Assessment of these pro-angiogenic growth factors and enumeration of tumour-associated microvessels have been shown to be prognosticators of ovarian cancer outcome, and may also be surrogates of ovarian cancer tumour burden and/or ascites formation. The process of angiogenesis has been targeted for therapeutics development. Ovarian cancer is a primary cancer against which these new agents are being tested. Thus, further understanding of the molecular and cell biology of angiogenesis in the context of ovarian cancer offers important directions for estimation of patient outcome and for patient treatment.

Induction of matrix metalloproteinases 2 and 9 following stress to the lens

Matrix metalloproteinase 2 and 9 (MMP-2 and 9, also known as gelatinase A and B) have been implicated in a number of eye diseases, but their possible involvement in lens pathology is yet to be determined. In the present study, we therefore investigated a possible role of matrix metalloproteinases in cataract and posterior capsule opacification. Whole porcine lenses were removed from the eye and cultured in either Eagles Minimum Essential Medium (EMEM) or EMEM supplemented with 1 m M hydrogen peroxide. The medium was sampled and changed every 2 days. On some occasions a sham cataract operation was performed on cultured lenses. The resulting capsular bag was secured to a Petri dish and cultured in EMEM. Culture media from all preparations were analysed for MMP-2 and 9 activity by gelatin zymography. Media samples from lenses which maintained clarity over the 6 day culture period did not display any detectable gelatinolytic activity. However, media from cataractous lenses demonstrated a gelatinolytic band, which had similar molecular weights to the pro-form of MMP-2. In addition to this band, bands with a similar molecular weight to pro-MMP-9 and its dimeric form were also detected in samples obtained from capsular bag preparations within 24 hr. The data presented indicate that normal lenses have undetectable gelatinase activity. However, there is an associated expression of gelatinases with pathological states of the lens, and therefore gelatinase expression could play an important role in cataractogenesis and posterior capsule opacification.

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

OBJECTIVES

The aim of our study was to determine the important molecules responsible for the invasive activity of ovarian cancer cells.

METHODS

We compared the biological characteristics, that is, growth rate, motility, and invasive activity, of five ovarian cancer cell lines with the gene expression of various matrix proteases (matrix metalloproteinase-1 [MMP-1], MMP-2, MMP-9, membrane-type MMP type 1 [MT1-MMP], MT2-MMP, MT3-MMP, urokinase plasminogen activator [uPA]), their inhibitors (tissue inhibitor of metalloproteinase type 1 [TIMP-1], TIMP-2, plasminogen activator inhibitor type 1, [PAI-1], and PAI-2), and the potential transcriptional regulators E1AF and Ets-1.

RESULTS

There was no clear correlation in the growth rate, motility, and invasion, suggesting that there are independent properties for malignant potential in ovarian cancer cells. However, HTBOA, a poorly differentiated cancer cell line, exhibited highly invasive activity, rapid growth, and increased motility. This cell line also expressed both Ets transcriptional factors, E1AF and Ets-1, and many matrix-degrading enzymes. Three cell lines that expressed E1AF showed rapid cell growth. The highly invasive cell lines, HTBOA and HTOA (well-differentiated serous cystadenocarcinoma), produced either MMP-2 or MMP-1, and both cell lines expressed MT1-MMP and uPA. Furthermore, the active forms of pro-MMP-2 and pro-MMP-1 were detected in HTBOA and HTOA by zymography.

CONCLUSION

We conclude that activated MMP-2 and MMP-1 are important in the invasive activity of these ovarian cancer cells.

Suppression of the c-erbB-2 gene product decreases transformation abilities but not the proliferation and secretion of proteases of SK-OV-3 ovarian cancer cells

The overexpression of the c-erbB-2 oncogene product has been reported in approximately 20-30% of human ovarian cancers and has been correlated with a poor prognosis in ovarian cancer patients. To investigate the function of p185(c-erbB-2) in human ovarian cancer cells, a c-erbB-2-specific single-chain antibody (scFv-5R) was expressed in the c-erbB-2-overexpressing SK-OV-3 cell line using a retroviral expression vector. Eight individual clones expressing the single-chain antibody were isolated. These clones have a prominent retention of the cell surface p185(c-erbB-2). In this study we compared the proliferation rate, the anchorage-independent growth, the secretion of matrix metalloproteases and of the urokinase-type plasminogen activator. The clones expressing the c-erbB-2 single-chain antibody, the control cells harbouring the empty vector and the parental SK-OV-3 cells they all had similar proliferation rates in the presence of 10% serum and secreted similar amounts of matrix metalloproteases and of the urokinase-type plasminogen activator. However, the expression of the c-erbB-2 oncogene product offers a strong growth advantage under serum-reduced conditions with 1% serum. In contrast to the parental SK-OV-3 and empty vector control cells, the scFv-5R-expressing clones were not able to grow anchorage-independently. These findings suggest that c-erbB-2 enhances transformation abilities of SK-OV-3 ovarian cancer cells without affecting the secretion of proteases and the proliferation of SK-OV-3 ovarian cancer cells in the presence of high concentrations of serum.

Matrix metalloproteinases and their inhibitors in gestational trophoblastic diseases and normal placenta

OBJECTIVE

Our purpose was to investigate the expression of matrix metalloproteinases (MMPs) in gestational trophoblastic diseases and normal first-trimester placenta.

METHODS

Paraffin sections of 16 partial moles, 25 complete moles, 10 gestational choriocarcinomas, and 11 normal first-trimester placentas were studied immunohistochemically for expression of MMP-1, MMP-2, MMP-3, MMP-9, MMP-13, and tissue inhibitor of metalloproteinase-1 (TIMP-1).

RESULTS

Nine (90.0%) of the choriocarcinoma cases showed strong intensity of staining for MMP-1. Choriocarcinoma exhibited significantly stronger staining for MMP-1 than syncytiotrophoblast in normal placenta (P < 0.01), partial mole (P < 0.01), and complete mole (P < 0.01). Choriocarcinoma also showed significantly stronger staining for MMP-1 than the extravillous trophoblast in placenta (P < 0.05). MMP-2 was expressed only in syncytio- and extravillous trophoblasts in normal placenta, partial mole, and complete mole. Choriocarcinoma and the extravillous trophoblast in partial mole and complete mole had significantly stronger staining for MMP-2 than the extravillous trophoblast in placenta (P < 0.05, P < 0.01, P < 0.01, respectively). Choriocarcinoma also exhibited significantly stronger staining for MMP-2 than syncytiotrophoblasts in placenta (P < 0.01), partial mole (P = 0.05), and complete mole (P < 0.01). The expression of MMP-3, MMP-9, and MMP-13 was similar in all four tissues with the predominance of syncytiotrophoblast for MMP-3 and MMP-13 and cytotrophoblast for MMP-9. While 8 (73.0%) placentas, 14 (87.5%) partial moles, and 19 (76.0%) complete moles showed strong immunoreactivity for TIMP-1 in syncytiotrophoblasts, no strong staining was found in choriocarcinomas (P < 0.01, P < 0.01, P < 0.01, respectively).

CONCLUSION

The extravillous trophoblast of first-trimester placenta has significantly less expression of MMP-1 than choriocarcinoma and significantly less expression of MMP-2 than choriocarcinoma and extravillous trophoblast of partial and complete mole. The expression of TIMP-1 was significantly less in choriocarcinoma than the syncytiotrophoblast of normal placenta, partial mole, and complete mole. MMPs and their inhibitors may play a role in the pathogenesis of gestational trophoblastic diseases.

Enhanced production and activation of matrix metalloproteinase-7 (matrilysin) in human endometrial carcinomas

We examined production and tissue localization of 7 different matrix metalloproteinases (MMP-1, -2, -3, -7, -8, -9 and -13) and 2 tissue inhibitors of metalloproteinases (TIMP-1 and -2) in human endometrial-carcinoma tissues. Sandwich enzyme immunoassays showed enhanced production of MMP-7, MMP-8 and MMP-9 as well as TIMP-1 in the carcinoma tissues compared with non-carcinoma endometrial tissues. Among these MMPs, only the amount of MMP-7 correlated with clinicopathological factors of the carcinomas. The level was significantly 6.8-fold higher in the patient group with lymph-node metastases than in that without metastases (p < 0.05), and also increased with the progress of the clinical stage. MMP-7 was immunolocalized predominantly to the carcinoma cells in 73% of the cases, while MMP-8 and MMP-9 were immunostained in the inflammatory cells infiltrated in the carcinoma tissues. Immunoblotting revealed a definite band for the zymogen of MMP-7 (proMMP-7) of 28 kDa in 82% of the carcinoma samples, while only a faint band for proMMP-7 was seen in 57% of the non-carcinoma endometrial samples. Active MMP-7 species of 19 kDa and its activity were demonstrated in the carcinoma samples with proMMP-7 production by immunoblotting and zymography, respectively. RT-PCR using a specific primer pair for MMP-7 demonstrated expression in 86% of the carcinoma tissue and in 57% of the control tissue samples. In situ hybridization showed carcinoma cells selectively expressing MMP-7 mRNA. These data suggest that, among the 7 MMPs examined, MMP-7 may play a key role in invasion and lymph-node metastasis of human endometrial carcinomas.

Ovarian carcinoma cell cultures are resistant to TGF-beta1-mediated growth inhibition despite expression of functional receptors

OBJECTIVE

The purpose of this study was to determine the response of ovarian carcinoma cells to TGF-beta1 and to examine components of the TGF-beta signaling pathway.

METHODS

Twenty-three primary ovarian cancer cell (CSOC) cultures established from solid ovarian carcinomas were treated with TGF-beta1 and assayed for growth response by MTT assay. Expression of TGF-beta receptor I (TbetaR-I) and receptor II (TbetaR-II), essential for effective signaling, was determined by Western analysis of CSOC cultures. TGF-beta1 ligand-induced phosphorylation of TbetaR-I was determined by immunoprecipitation of TbetaR-I followed by a protein kinase assay to assess TbetaR-I phosphorylation, an essential first step in TGF-beta signal transduction. Gelatin zymography performed on 5 CSOC cultures incubated with TGF-beta1 was used to determine TGF-beta's effect on matrix metalloproteinase production. Normal ovarian surface epithelial cells were used for comparison.

RESULTS

Eighteen of twenty-three (78%) CSOC cultures demonstrated no significant growth inhibition in response to TGF-beta1 treatment. All cell cultures expressed TbetaR-I and TbetaR-II and exhibited TbetaR-I phosphorylation following TGF-beta1 treatment. CSOC cultures produced significantly higher levels of matrix metalloproteinase-2 (MMP-2) than normal ovarian surface epithelial cells; however, the level of MMP-2 expression was not regulated by TGF-beta1.

CONCLUSION

These results indicate that TGF-beta1 resistance and higher levels of MMP-2 production may be inherent properties of the ovarian cancer phenotype. The initial steps in the TGF-beta signaling pathway, receptor expression, ligand binding, and TbetaR-I phosphorylation, appear to be functional in primary ovarian cancer cell cultures. Therefore, the mechanism of growth resistance is downstream of TbetaR-I phosphorylation.

MMP-2 release and activation in ovarian carcinoma: the role of fibroblasts

The matrix metalloproteinase MMP-2 is up-regulated in epithelial cancers and its mRNA localizes to stromal fibroblasts. In this paper we show that co-culture of ovarian carcinoma cells with fibroblasts resulted in an enhanced release of proMMP-2 and TIMP-2 into the culture medium. Cell-cell interaction was a major factor in this response and carcinoma cells stimulated proMMP-2 release from fibroblasts but not vice versa. Collagen 1, in a dose-dependent fashion, induced activation of proMMP-2 by tumour-derived, but not normal, fibroblasts. Antibody to beta1 integrin also induced proMMP-2 activation by tumour-derived fibroblasts. The activation involved the processing of proMMP-2 by a membrane-bound metalloproteinase. We propose that, in the ovarian tumour microenvironment, interaction between tumour cells and fibroblasts may enhance fibroblast production of the proMMP-2 and TIMP-2. Collagen I, also present in the ovarian tumours, then induces these fibroblasts to activate proMMP-2 even in the presence of TIMP-2. This active MMP-2 can associate with the cell surface of tumour cells and fibroblasts and is used in the processes of tissue remodelling and invasion.

A novel microbial infection-responsive drug release system

The aim of this study was to construct a novel drug delivery system suitable for controlled release of antibiotics. There is a need for devices that release antibiotics only during microbial infection, because prophylactic or prolonged use of antibiotics leads to serious problems, such as renal and liver toxicity and the emergence of drug-resistant bacteria (e.g., meticillin-resistant Staphylococcusaureus). We found previously that Staphylococcus aureus-infected wound fluid showed high thrombin-like activity; therefore, in this study we designed an antibiotic release system triggered by thrombin activity. We synthesized an insoluble polymer-drug conjugate in which gentamicin was bound to poly(vinyl alcohol) hydrogel through a newly developed thrombin-sensitive peptide linker. The conjugate released gentamicin when it was incubated with Staphylococcus aureus-infected wound fluid, with thrombin and leucine aminopeptidase, or with human plasma and Ca2+, whereas no biologically active gentamicin was released when the conjugate was incubated with noninfected wound fluid, with leucine aminopeptidase alone, with thrombin alone, or with plasma. Furthermore, the conjugate reduced the bacterial number in an animal model of Staphylococcus aureus infection. These results demonstrated that the conjugate has sufficient specificity and excellent potential as a stimulus-responsive, controlled drug release system.

Expression of matrix metalloproteinase-9 in squamous cell carcinoma of the uterine cervix-clinicopathologic study using immunohistochemistry and mRNA in situ hybridization

OBJECTIVE

Invasion of the extracellular matrix and blood vessels by malignant neoplasms, with subsequent distant dissemination, is a key event in tumor progression. This process appears to be mediated largely through the action of matrix metalloproteinases (MMPs), a family of proteolytic enzymes produced by both stromal and tumor cells. The role of gelatinases (MMP-2 and MMP-9) in basement membrane and matrix degradation was described in various tumors. We studied MMP-9 protein expression in cervical intraepithelial neoplasia (CIN) and squamous cell carcinoma using immunohistochemistry and detected MMP-9 mRNA using in situ hybridization.

METHODS

Fifty squamous cell carcinomas, 10 cases of CIN II-III, and 10 normal cervices were stained for MMP-9, using a monoclonal antibody. The presence of MMP-9 mRNA was studied using in situ hybridization. Results were correlated with patient survival during a follow-up period of up to 167 months (average, 41 months).

RESULTS

Immunohistochemical staining of tumor cells for MMP-9 was noted in 36/50 (72%) carcinomas and 5/10 (50%) CIN lesions, but was uniformly absent from the nonneoplastic epithelium adjacent to tumors and from control cervices. Peritumoral staining of stromal cells was observed in 27/50 (54%) carcinomas, but only in 3/10 (30%) CIN lesions and 1/10 (10%) control cervices. The presence of MMP-9 mRNA was detected in tumor cells in 39 (78%) carcinomas and 8 (80%) CIN lesions, but only in 4 (40%) control cervices. An intense signal for MMP-9 mRNA was observed most frequently in carcinomas. MMP-9 mRNA was detected in stromal cells in the majority of cases. However, an intense signal was observed only in stromal cells around invasive tumors. In survival analysis, age (P = 0.016), grade (P = 0. 016), and stage (P = 0.001) showed independent correlation with poor survival. Neither MMP-9 protein expression nor an intense signal for MMP-9 mRNA was associated with poor survival, although the latter was observed more frequently in neoplastic cells of lethal tumors (8/14 tumors vs 11/36 nonlethal tumors).

CONCLUSIONS

MMP-9 mRNA and protein expression are elevated in tumor and stromal cells of both high-grade CIN and invasive squamous cell carcinoma of the uterine cervix. Thus, MMP-9 is possibly an early marker of tumor progression in squamous lesions of the cervix. An intense stromal signal for MMP-9 mRNA characterizes some invasive carcinomas. Expression of MMP-9 in cervical carcinoma cells is present in both lethal and nonlethal tumors, consistent with the key role of this proteolytic enzyme in invasion, and does not appear to predict disease outcome.

Collagenase-3 (MMP-13) is expressed by tumor cells in invasive vulvar squamous cell carcinomas

Collagenase-3 (MMP-13) is a human matrix metalloproteinase specifically expressed by invading tumor cells in squamous cell carcinomas (SCCs) of the head and neck. Here, we have further elucidated the role of MMP-13 in tumor invasion by examining its expression in invasive malignant tumors of the female genital tract. Using in situ hybridization, expression of MMP-13 mRNA was detected in 9 of 12 vulvar SCCs, primarily in tumor cells, but not in intact vulvar epithelium, in cervical SCCs (n = 12), or in endometrial (n = 11) or ovarian adenocarcinomas (n = 8). MMP-13 expression was especially abundant in vulvar carcinomas showing metastasis to lymph nodes and was associated with expression of membrane type 1 MMP by tumor cells and gelatinase-A (MMP-2) by stromal cells, as detected by immunohistochemistry. MMP-13 mRNAs were detected in 9 of 11 cell lines established from vulvar carcinomas and in 4 of 6 cell lines from cervical carcinomas, whereas endometrial (n = 10) and ovarian (n = 9) carcinoma cell lines were negative for MMP-13 mRNA. No correlation was detected between MMP-13 expression and p53 gene mutations in vulvar SCC cell lines. However, MMP-13 expression was detected in 5 of 6 vulvar and cervical SCC cell lines harboring HPV 16 or 68 DNA. These results show that MMP-13 is specifically expressed by malignantly transformed squamous epithelial cells, including vulvar SCC cells, and appears to serve as a marker for their invasive capacity.

Involvement of matrix metalloproteinase-2 activity in invasion and metastasis of pancreatic carcinoma

BACKGROUND

Activation of matrix metalloproteinase-2 (MMP-2) has been implicated in the progression, invasion, and metastasis of various cancers, but little information is available with regard to its role in pancreatic carcinoma with poor prognosis.

METHODS

Gelatin zymography was used for the detection of latent and activated forms of MMP-2 and MMP-9 in 13 normal pancreatic tissue specimens, 14 chronic pancreatitis tissue specimens, and 33 pancreatic carcinoma tissue specimens. The gelatinase activity was quantified by densitometer, and the 66-kilodalton (kDa)/(66-kDa + 72-kDa) ratio was calculated as the MMP-2 activation ratio. Western blot analysis was performed to confirm the zymographic profile.

RESULTS

Latent forms of MMP-2 and MMP-9 were detected in all samples of pancreatic carcinoma, chronic pancreatitis, and normal pancreatic tissue. The expression rate of the MMP-2 activated form in pancreatic carcinoma tissue specimens was 100% (33 of 33) but that of MMP-9 was 21%. The MMP-2 activation ratio in pancreatic carcinoma tissue specimens was significantly higher than that of chronic pancreatitis and normal pancreatic tissue specimens. The MMP-2 activation ratio in pT3 tumors was significantly higher than that in pT1 tumors. The MMP-2 activation ratio also was significantly higher in pancreatic carcinoma specimens with histologically positive regional lymph node metastasis and distant metastasis than those without metastasis. The MMP-2 activation ratio observed in patients who developed postresection recurrence within 6 months was significantly higher than that in patients without recurrence at 6 months.

CONCLUSIONS

The results of the current study indicate that MMP-2 activation plays a significant role in tumor invasion and metastasis in pancreatic carcinoma.

Thrombin-sensitive peptide linkers for biological signal-responsive drug release systems

We have previously reported an elevation of thrombin-like activity in infected wound exudates. Therefore, using this enzymatic activity as a biological signal, a system which can release an antimicrobial drug at infected wounds was investigated. In this paper, we report thrombin-sensitive peptide linkers, the key component of this system. Starting from amino acid sequences of the cleavage site in fibrinogen, which is the substrate of thrombin, we synthesized some thrombin-sensitive peptide linkers. We constructed devices in which the thrombin-sensitive peptide linker interconnected between polyvinyl alcohol hydrogel and gentamicin. The device was able to release gentamicin in response to thrombin.

Increased matrix metalloproteinase-9 activity in human ovarian cancer cells cultured with conditioned medium from human peritoneal tissue

Ovarian cancer cells disseminate by attachment to the peritoneal mesothelial cell surface of the abdominal cavity. We therefore investigated the influence of conditioned medium (CM) from human peritoneal tissues and mesothelial cells on the secretion of matrix metalloproteinases (MMPs) by ovarian cancer cells. The molecular weights of MMPs stimulating factors derived from human peritoneal tissues and mesothelial cells were estimated using microconcentrators with various cut-off membranes. Human peritoneal tissues were obtained from 12 surgical patients, and mesothelial cells were isolated from three peritoneal specimens. Exposure to CM from peritoneal tissue caused a concentration-dependent increase of the MMP-2 and MMP-9 bands in CM from NOM1 ovarian cancer cells, as shown by zymography. There was a significant difference in the increase of MMP-2 and MMP-9 (2.46-fold and 7.14-fold, respectively, at 0.4 mg/ml protein; P < 0.005). CM from mesothelial cells also significantly increased the secretion of MMP-9 by NOM1 cells. The molecular size of possible MMP-9-stimulating factors secreted by peritoneal tissues and mesothelial cells was above M(r) 100000. Further, CM of peritoneal tissues and mesothelial cells also induced the invasiveness of NOM1 cells. These findings suggest that mesothelial cells may secrete some factors which predominantly induce the MMP-9 production and increase invading cell numbers.

Immunohistochemical studies on matrix metalloproteinase-9 (MMP-9) and type-IV collagen in endometrial carcinoma

Immunohistochemical staining of MMP-9 and the type-IV collagen was performed on paraffin sections of endometrial carcinoma. Immunostaining in 129 cases of endometrial cancer detected MMP-9 in 19.0% of the cases. MMP-9 positive was shown in 30% of the cases with vessel invasion, and in 12.7% of the cases without vessel invasion (p < 0.05). MMP-9 showed positive in many cases with poor differentiation and lymph node metastasis, but still failed to achieve statistical significance. MMP-9 staining did not correlate with disease outcomes. We can not clarify that MMP-9 is associated with tumor-cell invasion and metastasis. Type-IV collagen deposition at the tumor-stromal border was studied in 58 cases of endometrial carcinoma in which disruptions were seen in varying degrees. The type-IV collagen in the primary lesion decreased as the differentiation decreased. Even in the lymph node metastasis lesions, the type-IV collagen was stained and was almost in agreement with the primary lesions. In the primary lesions, there was no relationship between MMP-9 staining and the type-IV collagen. It was suggested that the type-IV collagen observed in endometrial carcinoma was more concerned with the differentiation of the tumor than with the degradation by MMP-9.