Epigenetic role of the nuclear factor NF-Y on ID gene family in endometrial tissues of women with endometriosis: a case control study

Background A predominant difference between endometrial and normal cells is higher proliferation rate in the former cells which is benign. The genes of inhibitor of differentiation ( ID ) family play a major role in cell proliferation regulation which might be targeted by the nuclear transcription factor Y (NF-Y) for subsequent epigenetic modifications through the CCAAT box regulatory region. The present study was designed to investigate the epigenetic role of NF-Y on ID gene family in endometrial tissue of patients with endometriosis. Materials & methods In this case-control study, 20 patients with endometriosis and 20 normal women were examined for the relative expression of the NF-YA , NF-YB , NF-YC and ID genes by real-time PCR during the proliferative phase. The occupancy of NF-Y on CCAAT box region of ID genes was investigated using chromatin immunoprecipitation (ChIP) followed by real-time PCR. Results The NF-YA was over-expressed in eutopic endometrium during the proliferative phase. Although the expression level of NF-YB and NF-YC were unchanged in eutopic samples, they were remarkably higher in ectopic group ( P <0.05). The ID2 and ID3 genes were up-regulated in ectopic and eutopic tissues, however ID1 and ID4 genes were down-regulated in these samples ( P <0.05). The ChIP analysis revealed significant enrichment of NF-Y on regulatory regions of ID2,3 genes in eutopic group, but reduced binding level of NF-Y to the ID1,3 promoters in ectopic specimens ( P <0.05). Conclusion The ability of NF-Y to regulate ID genes via CCAAT box region suggests the possible role of NF-Y transcription factor in epigenetic changes in endometrial tissues which may open novel avenues in finding new therapeutic strategies.