Expression and significance of MMP-9 and TIMP-1 in endometriosis

AIM: To observe the expression of matrix metalloproteinase 9 (MMP 9) and tissue inhibitors of matrix metalloproteinase 1 (TIMP 1) in endometriosis, to explore the correlation between the expression of MMP 9 and TIMP 1 in endometriosis and to study the possible role of MMP 9 and TIMP 1 in the pathogenesis of endometriosis. METHODS: Expressions of MMP 9 and TIMP 1 in 84 normal endometrium as well as in 79 ectopic endometrium and 48 eutopic endometrium in endometriosis were detected by immunohistochemistry and the results were analyzed with SPLM statistical software. RESULTS: (1) The expression levels of MMP 9 in ectopic and eutopic endometriotic tissues were significantly higher than those in the normal endometrium (P0.05). In ectopic and eutopic endometrium of endometriosis and normal endometrium, the positive rates of MMP 9 were 78%, 71% and 50% respectively (P 0.05 ). (2)In ectopic and eutopic endometrium of endometriosis and normal endometrium, the positive rates of TIMP 1 were 84%, 71% and 80 %, respectively. There were no noticeable difference of the positive expression rates of TIMP 1 in endometriosis and normal endometrium (P 0.05 ). (3)There was significantly negative correlation between expression of MMP 9 and TIMP 1 in normal endometrium . But there was no correlation between the expression of MMP 9 and TIMP 1 in ectopic/eutopic endometrium of endometriosis. CONCLUSION: The high expression of MMP 9 and the lopsided development on MMP 9/TIMP 1 ratio may participate in the process of invasion and tissue remodeling that is hypothesized to occur in the pathogenesis of endometriosis. They are maybe one of the reasons why ectopic and eutopic endometriatic cells have stronger invasive ability than the normal endometric cells.