Effect on proliferation and apoptosis in RPMI-8226 human myeloma cells and regulation on steroid receptor coactivator-3 by deguelin / 中草药

ABSTRACT

Objective To investigate the effects of deguelin on the proliferation inhibition and apoptosis induction in RPMI-8226 cells in vitro,as well as the regulation of steroid receptor coactivator-3(SRC-3)to explore the relationship between them.Methods The effect of deguelin on the growth of RPMI-8226 cells was studied by MTT assay.Apoptosis was detected through Hoechst 33258 staining and Annexin-V FITC/PI double-labeled cytometry.RT-PCR Technology was applied to assessment of the mRNA expression of SRC-3,whereas,SRC-3 protein expression and localization were determined by using immunohistochemistry method.Results Deguelin presented striking proliferation inhibition potency on RPMI-8226 cells in vitro and apoptosis induction activity in a time-and dose-dependent manner.The IC50 value for 24 h was(54.55?0.40)nmol/L,(17.04?0.73)% RPMI-8226 cells went apoptotic when treated with 25 nmol/L deguelin for 24 h,with the dose of deguelin increasing to 100 nmol/L,(63.57?1.36)% cells were apoptotic.Over-expression of SRC-3 was found in RPMI-8226 cells,whereas the mRNA and protein expression levels of SRC-3 were significantly downregulated in RPMI-8226 cells induced by deguelin in a dose-dependent manner.The disposition of SRC-3 was situated mainly at the nuclear,occasionally in the cytoplasm.Conclusion Deguelin exhibited potent proliferation inhibition to the human myeloma cell line RPMI-8226 cells,furthermore,deguelin might induce RPMI-8226 cells apoptosis in a dose-dependent manner,which might correspond to the regulation of the expression of SRC-3.