The effect of a single low dose mifepristone on HOXA11 gene expression of the human endometrium in the mid-secretory phase

Objective: The objective of this study was to investigate the expression of HOXA11 gene, progesterone receptor (PR) and leukemia inhibitory factor (LIF) proteins in the mid secretory endometrium after the treatment of mifepristone. Methods: Thirteen healthy female volunteers with normal menstrual cycles took a single dose of 10 mg of mifepristone in pre or post ovulation phase. Endometrial biopsies in the control and treatment cycles were collected on the 7 th day after the plasma luteinizing hormone (LH) surge. In situ hybridization was used to analyze HOXA11 gene expression and the immunohistochemical staining to examine the expression of PR and LIF. Results: In the control group the expression of HOXA11 gene and PR protein in the glandular epithelial cells was negative or mildly positive. After treatment with mifepristone, the expression of HOXA11 and PR was up regulated and LIF was down regulated in the glandular epithelial cells, while no differences were observed in stromal cells. Conclusion: The results suggest that the normal down regulation of HOXA11 expression in the glandular epithelial cells of mid secretory endometrium, as with the same pattern of PR, is a sign of differentiation and development maturation of endometrium, and also prerequisite for LIF peak expression in secretory phase.