Next-Generation Sequencing Reveals Downregulation of the Wnt Signaling Pathway in Human Dysmature Cumulus Cells as a Hallmark for Evaluating Oocyte Quality

Background: Dysmature cumulus cells are lower fertilization rates and abnormalities in embryonic development compared to maturation cumulus cells. Morphological evaluation of cumulus–oocyte complexes (COCs) considered the possibility that differences may also be found in gene expression. Purpose: To identify hallmarks for evaluating oocyte quality by investigating gene expression patterns in human cumulus cells surrounding oocytes. Methods: Cumulus cells were obtained from the cumulus–oocyte complex of infertile women treated with assisted reproductive technology. Based on maturity level, the cumulus cells were classified into two categories, i.e., dysmature cumulus cell (DCC) and maturation cumulus cell. DCCs were subjected to gene expression analysis using next-generation sequencing and compared with COCs that are in the process of maturation as controls. Results: The expression levels of genes involved in the Wnt signal/β-catenin pathway were significantly reduced in DCCs compared with those in control cells. Moreover, the expression levels of genes involved in multiple pathways associated with apoptosis were also significantly reduced compared with those in control cells. Conclusions: DCCs showed significant decreases in apoptosis- and Wnt/β-catenin signaling-associated gene expression. DCCs could be classified by morphological evaluation, and the method described in this study may be useful as an oocyte quality estimation tool. View Full-Text