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

Abstract Background: Endometriosis(EM) is a major cause of infertility, but the pathogenesis and mechanisms have not been fully elucidated. MiR-19b-3p is involved in many diseases, but its functional role in EM-associated infertility has not been investigated. In this study, we aimed to examine miR-19b-3p abundance and IGF1 concentration in cumulus cells (CCs) and follicular fluid in EM-associated infertility patients and to reveal the potential role of miR-19b-3p in KGN cells by identifying its target and elucidating the underlying mechanisms. Results: The results showed that compared to the control group (patients with tubal infertility), EM-associated infertility patients had a lower percentage of mature oocytes. Abundance of miR-19b-3p was increased in CCs in EM-associated infertility patients. IGF1 was 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 viability and proliferation, promoted apoptosis, and arrested cell cycle at G0/G1 phase in KGN cells. The effects of miR-19b-3p could be reversed by co-transfection of IGF1 and the biological effects of miR-19b-3p in KGN cells were mediated by IGF1. In addition, miR-19b-3p targeted IGF1 to downregulate AKT phosphorylation and to participate in apoptotic pathway in KGN cells. Conclusions: This study demonstrates that miR-19b-3p abundance is increased in CCs and IGF1 concentration is decreased in follicular fluid in EM-associated infertility patients, and miR-19b-3p participates in the regulation of biological effects of KGN cells by targeting IGF1.