Aberrant Methylation of the E-Cadherin Gene Promoter Region in Endometrium and Ovarian Endometriotic Cysts of Patients with Ovarian Endometriosis

Abstract

The loss of E-cadherin expression plays an important role in the development of endometriosis, but the molecular mechanism is not clear to date. It has been confirmed that the hypermethylation of the CpG island may be an important molecular mechanism in the transcriptional inactivation of E-cadherin gene (CDH1) in many cancers. The present study investigated the methylation status of CDH1 promoter region in ovarian endometriotic cysts and the endometrium of women with ovarian endometriosis. The results showed that the frequency of CDH1 promoter methylation in eutopic (26%), ectopic tissues (32%) of women with ovarian endometriosis was significantly higher than that of endometrium tissue of women without endometriosis (8%). Further, results of the study showed that the expression level of mRNA and protein of E-cadherin in methylation-positive tissues was significantly lower than that in methylation-negative tissues (p = 0.023 and 0.035, respectively). Pearson's correlation coefficients analysis showed the level of CDH1 mRNA expression was closely related to the level of E-cadherin protein expression. The results implied that the aberrant methylation of the CDH1 promoter region in the endometrium of the women may contribute, at least in part, to the development of ovarian endometriosis.