O-31: Epigenetic Aberration of HOXA10 Gene in Human Endometrium throughout The Menstrual Cycle in Endometriosis

Background: Epigenetic aberration such as DNA methylation and histone modifications appear to be involved in various diseases such as Endometriosis. Here, we investigated the epigenetic regulation of HOXA10 promoter, as a crucial gene, responsible for uterine organogenesis, functional endometrial differentiation and endometrial receptivity, and its correlation with mRNA expression of this gene in eutopic and normal endometrium, during menstrual cycle. Materials and Methods: Epigenetic analysis of eutopic and normal endometrium which were assayed by Chromatin Immunoprecipitation (ChIP), by using anti- H3K9ac, MeCP2, H3K9Me2, H3K27Me3, H3K4Me3 antibodies and precipitated chromatin DNA was evaluated quantitatively by real-time PCR technique. To this end, eutopic endometrium samples were collected using laparoscopy from 20 women with documented endometriosis, and endometrial tissues were collected from 18 healthy fertile women as well who underwent laparoscopy for tubal ligation surgery as a control group. Ethical approval and informed patient consent were gained for the use of tissue samples. Results: Data showed a harmonious pattern between mRNA expression of HOXA10 and epigenetic regulation of its promoter region. In the way that in secretory phase, the epigenetic marks of H3K9ac and H3K4Me3, known to be associated with gene activation, were lower in eutopic endometrium in comparison with control group and also H3K9Me2, H3K27Me3 and MeCP2 marks, known to be associated with gene repression which were higher in eutopic endometrium in comparison with control group. Conclusion: Our findings suggest that epigenetic be greatly responsible for aberrant expression of HOXA10 gene in endometrium of patient with endometriosis.