MiR-21 confers apoptosis resistance to temozolomide in glioblastoma U87 cells in vitro

Abstract

Objective To explore the function and mechanism of miR - 21 overexpression in glioblastoma U87 cells apoptosis induced by temozolomide (TMZ).Methods miR- 21 over- expression vectors were transfected into U87 cells.After that,cell apoptosis was analyzed by Hoechst 33258 staining and flow cytometry.And the expression of Bax and Bcl - 2 was identified by Western blot,while Caspase - 3 activity was detected.Results TMZ could effectively induce the apoptosis of U87 ceils,upregulate the Bax expression,downregulate the Bcl -2 expression and increase PI3K activity.However,after U87 cells were pre -transfected with miR- 21 over- expression vectors, the effects induced by TMZ was partly inhibited.Conclusion Over- expression miR- 21 could inhibit TMZ -induced apoptosis in U87 cells,at least in part,by decreasing Bax/Bcl- 2 ratio and Caspase- 3 activity,which highlighted the possibility of miR- 21 overexpression in resistance to chemotherapy TMZ in glioblastomas. Key words: MicroRNAs; Temozolomide; Apoptosis; Glioma