Reduced expression of HOXA10 in the midluteal endometrium from infertile women with minimal endometriosis.

Recent human and animal studies have suggested that reduced HOXA10 expression in the implantation window of eutopic endometrium may contribute to infertility in women with endometriosis. Therefore, we examined the HOXA10 transcript, protein and HOXA10 promoter methylation levels in midluteal eutopic endometrium from 17 infertile women with minimal endometriosis and 15 healthy fertile women from a Polish cohort. Real-time quantitative PCR (RQ-PCR) and western blotting analysis revealed significantly lower levels of HOXA10 transcript (P=0.019) and protein (P=0.048) levels in eutopic endometrium from infertile women with endometriosis as compared to healthy fertile women. Moreover, sodium bisulfite sequencing of three HOXA10 CpG islands showed significantly higher methylation levels of genomic DNA from midluteal eutopic endometrium from infertile women with endometriosis as compared to healthy fertile women (P=0.006). We confirmed that DNA hypermethylation can be one of the potential molecular mechanisms silencing HOXA10 expression in the midluteal endometrium associated with infertility in women with endometriosis.