Epiregulin gene expression profiling in cumulus cells is reflective oocyte/embryo competence and potentially reliable predictor of embryodevelopmental competence in PCOS patients

Backgrounds: Polycystic ovary syndrome (PCOS) is a common endocrine and metabolicdisorder in women of reproductive age, and has a major impact both on fertility and on long-termhealth. In mammals, Cross-talk between the oocyte and cumulus cells is critical for oocytematuration and embryo competence. Cumulus cells (CCs) support oocyte development, while theoocyte influences follicular cell growth and differentiation. Over recent decades, numerousgrowth factors involved in the bidirectional signals between the somatic and germ cells havebeen identified. The function and impact of epidermal growth factor (EGF) signaling duringovulation and oocyte maturation has been characterized. However, little is known about the roleof EREG in PCOS. The aim of this study was to examine expression and potential functionalaspects of epiregulin in cumulus cell proliferation and oocyte competence in women with PCOS.Materials and Methods: CCs from oocytes in metaphase II (MII) stage of PCOS (n=۱۸) andnon-PCOS (n=۱۸) patients who underwent controlled ovarian stimulation were mechanicallyremoved shortly before ICSI. Quantitative real-time PCR (qPCR) was used to analyze changes ingene expression.Results: Our results demonstrate that consistent with our previous RNA-seq data, EREG wassignificantly (P<۰.۰۱) down-regulated in CC samples from the PCOS patients in comparisonwith the non-PCOS patients.Conclusion: The study highlights that EREG is differentially expressed in PCOS and non-PCOSpatients, in which suggests that EREG could be used as a biomarker to predict oocytecompetence or embryo development. Our results may be clinically important as they offer a newpotential strategy for the selection of the best oocyte from women with PCOS; and the use of thisoocyte to increase in vitro fertilization (IVF) success rates.

Keywords:

Polycystic ovary syndrome , Cumulus cells , Epiregulin , qPCR , Non-invasive biomarker