The Expression of miR-31 and its Target Gene FOXP3 in Recurrent Implantation Failure Patients

Objectives: Endometrial receptivity is a complex event that occurs during the midluteal phase of the menstrual cycle known as the “window of implantation”. During this period, the endometrium develops characteristics that allow the adhesion and invasion of the embryo to the uterine epithelium. Accordingly, the expressions of miR-31 and its target gene were evaluated to study the effect of miR-31 on FOPX3 gene expression in recurrent implantation failure (RIF) patients and normal fertile women. More precisely, the aim of this study was to understand the expression of miR-31 as one of the important regulators of the FOXP3 gene in the endometrium of RIF patients versus receptive endometria from fertile patients. Materials and Methods: This case-control study was conducted on 20 endometrial tissue samples of normal fertile women and RIF patients in order to evaluate miR-31 and its target gene expression. Results: According to the results of this study, a significant difference existed between RIF patients and normal fertile women (control group). The expression of the FOXP3 gene was more significant in the control group. miR-31 was also significantly expressed, which was due to the endometrial immunological disorder leading to the decreased expression of its target gene (FOXP3). Conclusions: In general, implant abnormalities and recurrent abortions were observed in RIF patients due to the decreased expression of the FOXP3 gene resulting from the inhibitory effects of miR-31.