Circulating and Endometrial Profiles of miR-145, miR-155-5p, miR-224, MPP-5, and PECAM-1 Expression in Patients with Repeated Implantation Failure: A Case Control Study

Objective: An association between microRNAs (miRNAs) and adhesion proteins expression with repeated implantation failure (RIF) has been recently reported; however, these findings are controversial. This study aims to evaluate the endometrial and circulating expressions of miR-145, miR-155-5p, and miR-224 in addition to the endometrial expressions of membrane protein palmitoylated-5 (MPP-5) and endothelial cell adhesion molecule-1 (PECAM-1) in patients with RIF compared to control subjects. Materials and Methods: This case-control study was carried out between June 2021-July 2022. Subjects included 17 patients with RIF and 17 control subjects, who had previous spontaneous term pregnancy with a live birth, who referred to the Medical Centre of Arash Hospital, Tehran, Iran. Endometrial tissue samples were obtained via hysteroscopy and Pipelle catheter in the RIF and control subjects, respectively. Plasma samples were collected after ovulation in all subjects. The expression levels of MPP5, PECAM-1, miR-224, miR-145, and miR-155-5p were evaluated by quantitative real-time polymerase chain reaction (qRT-PCR). The student's t test, chi-square, Mann-Whitney U, and analysis of covariance (ANCOVA) were used for data analyses.Results: RIF patients had less endometrial miR-155-5p expression, and higher endometrial and circulating expressions of miR-145 and miR-224 compared to control subjects. Endometrial PECAM-1 and MPP5 expression significantly decreased in patients with RIF compared to the control group. There was a positive correlation between circulating miR-224 and endometrial miR-155-5p, and between circulating miR-155-5p and endometrial PECAM-1 expression levels in patients with RIF.Conclusion: The present study suggests that circulating miR-224, endometrial miR-145, and PECAM-1 can be reliable, novel biomarkers for diagnosis of RIF.