Received September 21, 2025
Accepted September 29, 2025

Objective: Since cumulus cells (CCs) play an undeniable role in oocyte maturation by producing and transferring important molecules to the oocyte, examining these cells can provide a broad view of the factors affecting oocyte competence. Therefore, the aim of this study was to investigate the expression of genes and proteins ZNF83, ACY-1, and SMC5 in CCs of unfertilized oocytes and compare it with fertilized oocytes to gain new insights into the relationship between CCs function and oocyte competence. Methods: Eighteen healthy female oocyte donors were included in this study. After obtaining the cumulus-oocyte complex and isolating the CCs, oocytes were injected and the embryos were followed and morphologically graded on day 3. Then the expression of genes and proteins ZNF83, ACY-1, and SMC5 in CCs of non-fertilized oocytes and CCs from fertilized oocytes was investigated and compared. Results: The expression of ZNF83, ACY-1, and SMC5 at the gene and protein levels was reduced in the non-fertilized group compared to the fertilized group (P < 0.05). Conclusion: The results highlight CCs' critical role in supporting oocyte fertilization. These findings shown the way for novel biomarkers and therapeutic strategies to improve IVF outcomes. More functional studies are needed to support the hypothesis of this study and explore the clinical applications of these markers in ART.