[DNA demethylation at the promoter region enhances the expression of MMP-9 in ectopic endometrial stromal cells of endometriosis].

OBJECTIVE: To investigate the role of DNA methylation in the regulation of matrix metalloproteinase 9 (MMP-9) gene expression in endometriosis. METHODS: MMP-9 gene methylation status in eutopic and ectopic endometria were analyzed by methylation specific PCR. The expression of MMP-9 protein in eutopic and ectopic endometria were detected by immunohistochemistry. We prepared the primary cultured ectopic endometrial stromal cells, and then examined the gene expression and methylation status of MMP-9 after the culture cells were treated with 5-Aza-2-deoxycytidine. RESULTS: The expression of MMP-9 in ectopic endometrial stromal cells was significantly higher than that in eutopic endometrium. MMP-9 methylation level was lower in ectopic endometrium. After treated with 5-Aza-dC, endometriosis cells showed elevated MMP-9 gene expression and methylation level. CONCLUSION: DNA methylation at the promoter region of MMP-9 gene can enhance the expression of MMP-9 in ectopic endometrial stromal cells of endometriosis.