Integrated bioinformatics analysis to identify key genes and pathways involved in the endometria of patients with recurrent implantation failure undergoing in vitro fertilization and embryo transfer

Objectives: Recurrent implantation failure (RIF) is a challenging clinical problem that occurs in approximately 10% of patients undergoingin vitro fertilization and embryo transfer. Because of the varied criteria for RIF, as well as differences in the time and methods of endometrial biopsy, previous studies have not reached an agreement regarding the key genes and pathways of RIF. In this study, bioinformatic analyses were performed in a homogeneous population with consistent biopsy conditions to explore the molecular mechanisms and identify key RIF-associated genes and pathways in the endometrium.Methods: Seven datasets from the Gene Expression Omnibus database were reviewed in detail, and GSE111974, GSE103465, and GSE26787 were included for further analysis. Common differentially expressed genes (DEGs) were identified using the GEO2R online tool. Gene Ontology and pathway enrichment analyses were performed and a protein–protein interaction (PPI) network was constructed. The RNA and protein expression files of the hub genes were obtained.Results: A total of 402 common DEGs were identified between patients with RIF and controls. The enrichment of these DEGs was mainly associated with tube morphogenesis, vasculature development, and positive regulation of cell migration. Pathway enrichment indicated that pathways involved in cancer, the vascular endothelial growth factor A-vascular endothelial growth factor receptor 2 signaling pathway, and cell cycle pathways were mainly involved. Moreover, a PPI network was constructed, and the three most significant submodules were mainly involved in rRNA processing and the regulation of proteolysis. The following ten DEGs with high degrees of connectivity were identified as hub genes:CDC42,VEGFA,MAP2K1,APP,CYCS,UBE2I,PLEK,LMNA,SMAD2, andATRX.Conclusion: Key genes and pathways identified in this study could improve our understanding of the underlying molecular events in RIF and be used as potential biomarkers and therapeutic targets. Further studies are required to confirm these results and explore the functions of hub genes in the endometrium during the implantation window in patients with RIF.