Expression of matrix metalloproteinase-7, E-cadherin and beta catenin in endometriosis: strategies for treatment of endometriosis might differ among different forms of endometriosis

Abstract

OBJECTIVE: To investigate expression of matrix metalloproteinase-7 (MMP-7), E-cadherin and beta catenin in different forms of endometriosis. DESIGN: Prospective study MATERIALS AND METHODS: Samples of deep infiltrating endometriosis (n= 46), ovarian endometriosis (n=38) and superficial peritoneal endometriosis (red lesions: n=24, black lesions: n = 30) were collected during laparoscopic surgery. In addition, benign ovarian cyst wall was collected from patients with serous (n=10) and mucinous cyst (n=10). None of the patients received hormonal treatments for ≥6 months before surgery. Immunohistochemical staining was performed on paraffin sections with mouse monoclonal antibodies to MMP-7, E-cadherin and beta catenin. The percentage of immunostained surface (PI) was obtained using a computerized image analysis system. RESULTS: The PI for MMP-7 in epithelial cells was significantly higher in red peritoneal lesions (72.1 ± 29.5, mean ± SEM, P<.0001) compared to that of deep infiltrating endometriosis (1.6 ± 0.7), ovarian endometriosis (2.4 ± 1.2) and black peritoneal lesions (8.2 ± 2.3). MMP-7 expression was detected in stromal and endothelial cells as well as fibrotic tissues in superficial peritoneal lesions. The PI for E cadherin was significantly lower in red peritoneal lesions (9.5 ± 2.4, p<.001) and ovarian endometriosis (17.7 ± 4.4, p<.01) compared to that of black peritoneal lesions (46.3 ± 4.5) and deep infiltrating endometriosis (40.1 ± 4.7). There was a significant negative correlation between MMP-7 and E-cadherin expression in superficial peritoneal lesions (p<.0001). Intense pre-nuclear staining of beta catenin in fibroblasts was detected in fibrotic tissue of ovarian endometriosis. CONCLUSIONS: Red peritoneal lesions might have the invasive phenotype. Beta catenin signaling pathway might be involved in fibrogenesis of ovarian endometriosis. The present findings suggested that strategies for treatment of endometriosis might differ among different forms of endometriosis.