Suppressing HOXA-10 Gene Expression by MicroRNA 135b During the Window of Implantation in Infertile Women

BACKGROUND: Implantation failure has long been identified as a common problem underlying low success rate of IVF. Currently, endometrial receptivity has gained expert attention as it is demonstrated to contribute to successful embryo implantation. MicroRNAs (miRNAs) is known to affect endometrial receptivity through post-transcriptional gene expression regulation. This study aimed to evaluate the expression of miRNA 135b and HOXA-10 during the implantation window in endometrial tissue of infertile women. METHODS: A total of 14 patients diagnosed with infertility in the gynaecology clinic of Cipto Mangunkusumo and Daya Medika hospitals Jakart, Indonesia were selected as the observed group, and 9 fertile patients were enrolled in the control group. Total RNA was isolated from endometrial tissues collected at the secretory phase of the menstrual cycle. The miRNA 135b and HOXA-10 mRNA expression were measured using quantitative real-time PCR (qPCR). The correlation between these variables was then determined using Pearson’s correlation coefficient. RESULTS: The expression of miRNA 135b in the infertile group was significantly higher by 1.81-fold compared to the control group (p<0.01), whereas, expression of HOXA-10 mRNA was significantly lower in the infertile group compared to the controls (p=0.047). Significant negative correlation was observed between the expression of miRNA 135b and HOXA-10 mRNA in infertile women (p=0.021; r=−0.607). CONCLUSION: Taken together, this study provides that alteration of miRNA expression is involved in regulating the implantation process partly via modulation of the expression of gene required for implantation.