KDM2B Regulates Let-7b Expression In Ovarian Cancer And Influences Cell Proliferation And Migration Ability

ObjectiveTo clarify the correlation between KDM2 B and Let-7b expression,we examined the expression of let-7b and the biological behavior in ovarian cancer A2780/SKOV3 cells after KDM2 B knockdown and over-expression.MethodsTo construct the KDM2 B knockdown and over-expression lentiviral vector,then infected the A2780 and SKOV3 cells,establishes the human ovarian cancer A2780/SKOV3 cells model that can express the target gene by Puromycin;The mRNA and protein level of KDM2 B were detected by Real-time quantitative PCR(qRT-PCR)and Western blotting at 72 h after infection;Expression of let-7b mRNA was analyzed by qRT-PCR after KDM2 B knockdown and over-expression;The effect of KDM2 B over-expression and knockdown on cell proliferation was evaluated in vitro by cell counting kit-8 assay(CCK-8);Cell migration ability was detected by wound healing assay and Transwell assay;Flow cytometry assay to analyze the cell cycle distribution and apoposis afterKDM2 B over-expression and knockdown;Chromatin immunoprecipitation assay(CHIP)to investigate the mechanism of let-7b regulated by KDM2 B.ResultsThe KDM2 B knockdown and over-expression lentiviral vector are successfully constructed,and the stably transfected cells can meet the follow-up experimental requirements;KDM2B negatively regulates the expression of let-7b;Overexpression of KDM2 B can significantly inhibit the expression of let-7b,promoted cells proliferation,migration,cell cycle progression and inhibit apoptsis in human ovarian cancer A2780/SKOV3cells;However,silencing KDM2 B gene can release its inhibitory effect in let-7b,expression of let-7b was significantly increased;KDM2B down-regulation declined the cell proliferation and migration ability,and inhibited cell cycle progression and arrest the cell in G0/G1 phase,promote the cell apoptosis;Further,KDM2 B up-regulation significant reduction of the histone methylation and RNA polymerase II bound to let-7b.ConclusionsThe KDM2 B gene directly bind to let-7b and demethylating the histones on let-7b,then interfering the RNA polymerase II bind to let-7b and inhibiting the let-7b transcription,promoting the development of ovarian cancer.