DNA methylation of HOXA10 in eutopic and ectopic endometrium

Abstract

STUDY QUESTION Does the methylation status of the promoter region of the HOXA10 gene differ in eutopic and ectopic endometrium? SUMMARY ANSWER The eutopic endometrium in women with endometriosis is significantly more methylated when compared with controls. WHAT IS KNOWN ALREADY Expression of the HOXA10 gene, which is important for successful implantation, is reduced in women affected by endometriosis. STUDY DESIGN, SIZE AND DURATION A pilot study was carried out including 18 women admitted for surgery for endometriosis-related pain (cases) and 12 women admitted for surgery because of non-endometriotic disease (control). Sample collection and analysis were performed between November 2010 and July 2013. PARTICIPANTS/MATERIALS, SETTING, METHODS Endometrial tissue (eutopic and ectopic) underwent sodium bisulfite DNA modification, PCR amplification of two regions of the HOXA10 promoter and pyrosequencing analysis. MAIN RESULTS AND THE ROLE OF CHANCE The eutopic endometrium of women with endometriosis was significantly more methylated compared with endometrium from the control group (sequence 1: 8.68% in cases and 6.25% in the control group: P = 0.037, sequence 2: 11.89% in cases and 9.25% in the control group: P = 0.032). The eutopic endometrium was significantly more methylated than the ectopic tissue in patients with endometriosis (mean difference -3.6 sequence 1: P = 0.001 and -6.0 sequence 2: P = 0.0001). LIMITATIONS, REASONS FOR CAUTION The study had a limited sample size and the fertility status of the majority of patients in our study was unknown. WIDER IMPLICATIONS OF THE FINDINGS Our data regarding methylation state of the ectopic tissues contribute to a better etiopathologic understanding of endometriosis. STUDY FUNDING/COMPETING INTEREST(S) No external funding was either sought or obtained for this study. The authors have no conflicts of interests to declare. © 2014 The Author.