18?-glycyrrhetinic acid-induced apoptosis and changed intracellular Ca~(2+) concentration in human breast carcinoma cells / 中国癌症杂志

ABSTRACT

Background and purpose:18?-glycyrrhetinic acid(GA) is one of the important components of glycyrrhiza.Recent years,studies showed that GA has the effect of proliferation inhibition in human acute lymphoblastic leukemia cells,human liver carcinoma and lung cancer cells.We investigated the effects of GA on induction of apoptosis in human breast carcinoma(MCF7) cells.The previous studies have demonstrated that the dynamic change of intracellular free Ca~(2+) concentration([Ca~(2+)]i)plays important roles in many links of apoptosis-induced process.Therefore we also researched the relationship between GA-induced apoptosis and [Ca~(2+)]i in MCF-7 cells.Methods:After MCF-7 cells were treated with 50-250 ?mol/L GA for 24 h,cell viability for proliferation was assessed by MTT assay.MCF-7 cells treated with 100 ?mol/L and 150 ?mol/L GA for 24 h,the apoptotic rates in MCF7 cells were examined by terminal deoxynucleotide transferase mediated dUTP nick-end-labeling method,flow cytometry with Annexin V/ propidium iodide fluorescent stain and single cell gel electrophoresis assay(SCGE).For cells treated with 150 ?mol/L GA for 24 h,i was measured by Fure-2 fluorescein load method.For cells treated with 150 ?mol/L GA combined with 100 ?mol/L BAPTA-AM or 0.5 mmol/L EGTA for 24 h,cell apoptosis were examined by SCGE.Results:For cells treated with GA from 100 ?mol/L to 250 ?mol/L,the rate of proliferative inhibition was increased significantly(P