MicroRNA-26b-3p inhibits human trophoblast cell proliferation, invasion and resistance to apoptosis via targeting SHBG

Abstract

Aberrant increased apoptosis and dysfunction in migration and invasion of trophoblast cell play key role in preeclampsia. However, the mechanism remains unclear. Our study investigated the roles of microRNA-26b-3p (miR-26b-3p) in trophoblast cell growth by targeting sex hormone binding globulin (SHBG). Human trophoblast cell line HTR8-SVneo was used in this study. Gain- and loss-of-functions of miR-26b-3p and SHBG were performed, and then the cell viability was detected with CCK-8 and EdU assays. Cell apoptosis was detected using flow cytometry, and the cell invasion and migration were evaluated with transwell assays. The expression level of SHBG, caspase-3 and Bcl-2 after miR-26b-3p transfection was measured with RT-PCR and western blot analysis. Matching the sequence of miR-26b-3p and SHBG was analyzed through bioinformatic prediction and confirmed with dual luciferase reporter assay. It is found that overexpression of miR-26b-3p inhibited HTR8-SVneo cell proliferation, invasion and migration, while increased cell apoptosis and induced cell cycle arrest at the G0/G1 phase. Elvated level of miR-26b-3p decreased the expression of SHBG. Bioinformatic prediction and dual luciferase assay identified the relation of miR-26b-3p and HTR8-SVneo. Downregulation of SHBG exhibited similar effects on HTR8-SVneo cell growth with overexpression of miR-26b-3p. Conclusion: MiR-26b-3p targets SHBG and decreases SHBG expression. It inhibits human trophoblast cell proliferation, invasion and resistance to death of trophoblast cell. This study provided a mechanism for preeclampsia. Sex hormone binding globulin: SHBG; miR-26b-3p: microRNA-26b-3p; CCK-8: Cell-Counting Kit-8; RT-PCR: Real time polymerase chain reaction; NC: miR-26b-3p mimic negative control or SHBG negative control siRNA; inhibitor NC: negative control inhibitor; TBST: Tris-buffered saline with Tween.