MiR-520h inhibits viability and facilitates apoptosis of KGN cells through modulating IL6R and the JAK/STAT pathway

This study embarked on the assessment regarding the function and mechanism of miR-520h/IL6R axis in polycystic ovary syndrome (PCOS). Specifically, we analyzed the differential expression of IL6R in PCOS samples and normal samples based on the GEO database, and then verified IL6R expression in KGN cells (Human granulosa-like tumor cell line) using quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) and western blot. MiRNA targeting IL6R was predicted by bioinformatics analysis and verified by luciferase reporter assay, qRT-PCR and western blot. KGN cells were transfected with miR-520h inhibitor and si-IL6R, and then the cell viability and apoptosis were detected by cell counting kit-8 (CCK-8) and flow cytometry assays. Additionally, western blot was applied to examine the expressions of cell cycle-, apoptosis-, and JAK / STAT pathway-related proteins. IL6R was highly expressed in PCOS and KGN cells, and IL6R silencing inhibited the viability, while promoting the apoptosis of KGN cells. Importantly, miR-520h directly targeted IL6R and inhibited IL6R expression. Moreover, downregulation of miR-520h enhanced the cell viability, impeded the cell apoptosis, upregulated the expressions of CDK2, CCNB1, Bcl-2, activated JAK/STAT pathway and downregulated Bax expression in KGN cells. Of note, knockdown of IL6R can reverse the biological functions of miR-520h in KGN cells. Collectively, miR-520h hindered the proliferation and promoted the apoptosis of KGN cells via targeting IL6R to inhibit the development of PCOS, and these effects were possibly realized by JAK/STAT pathway. However, the effect of miR-520h in the progression of PCOS need to further study in the GCs.