MiR-19b-3p inhibits cell viability and proliferation and promotes apoptosis by targeting IGF1 in KGN cells.

Background: Endometriosis (EM) is a major cause of infertility, but the pathogenesis and mechanisms are not yet fully elucidated. MiR-19b-3p is involved in many diseases, but its functional role in EM-associated infertility remains unexplored. This study aimed to examine miR-19b-3p abundance and IGF1 concentration in cumulus cells (CCs) and follicular fluid of EM-associated infertility patients, and to investigate the potential role of miR-19b-3p in KGN cells by identifying its target and elucidating the underlying mechanisms.

Results: The results from the case-control study indicated that, compared to the control group consisting of patients with tubal infertility, patients with EM-associated infertility exhibited a lower percentage of mature oocytes. MiR-19b-3p level was elevated in CCs from EM-associated infertility patients. IGF1 was identified as a direct target of miR-19b-3p and was negatively regulated by miR-19b-3p in KGN cells. Overexpression of miR-19b-3p significantly inhibited cell viability and proliferation, promoted apoptosis, and arrested the cell cycle at G0/G1 phase in KGN cells. The effects of miR-19b-3p were reversed by co-transfection of IGF1, and the biological effects of miR-19b-3p in KGN cells were mediated by IGF1. Additionally, miR-19b-3p targeted IGF1 to down-regulate AKT phosphorylation and participate in the apoptotic pathway in KGN cells.

Conclusions: This study demonstrates that miR-19b-3p level is elevated in CCs and IGF1 concentration is decreased in follicular fluid in patients with EM-associated infertility. MiR-19b-3p regulates the biological effects of KGN cells by targeting IGF1.