Effect of arsenic trioxide combined with γ-secretase inhibitor MW167 on drug resistance of human hepatocellular carcinoma HepG2/ADM cells / 吉林大学学报(医学版)

ABSTRACT

Objective:To investigate the influence of arsenic troxide (As2 O3) and γ-secretase inhibitor MW167used alone or in combination in the drug resistance of HepG/ADM cells,and to clarify its mechanisms.Methods:The HepG2/ADM cells were treated with different concentrations of As2 O3 (0.25,0.50,1.00,2.00,4.00,8.00mg· L-1) andMW167 (10,20,40μmol· L-1) for 24,48 and 72h,and MTT method was used to detect the optical density (A) values,then the inhibitory rates of proliferation were calculated and the drug concentration and treatment time were confirmed.The HepG2/ADM cells were divided into blank group,As2O3group,MW167 group and combination group;the non-cytotoxic doses of As2 O3 and MW167 according to the results of MTT were chosen and the HepG2/ADM cells were intervened for 48 h;the apoptotic rates were detected by FCM;RT-PCR and Western blotting methods were employed to detect the mRNA and protein expression levels of Notch-1,Hes-1,MDR-1 (P-gp),Bcl-2 and Bax in the cells in various groups.Results:At the same concentration,the inhibitory rates of proliferation of HepG2/ADM cells were enhanced with the prolongation of the treatment time of As2O3 and MW167 (P＜0.05 or P＜0.01);at the same time point,the inhibitory rates of proliferation of As2O3 and MW167 in the HepG2/ADM cells were increased with the increasing of drug concentration (P＜0.05);the non-toxic doses of As2O3 and MW167 were 0.25 mg · L-1 and 10 μmol · L 1 and the intervention time was 48 h.After treatment for 48 h,compared with blank group,the apoptotic rates in various intervention groups were increased (P＜0.05),especially in combination group (P＜0.01);the expression levels of Notch-1,Hes-1,MDR-1 (P-gp),Bcl-2 mRNA and protein in various intervention groups were lower than those in blank group (P＜0.05),especially in combination group (P＜0.01);compared with blank group,the expression levels of Bax mRNA and protein in various intervention groups were increased (P＜0.05),especially in combination group (P＜0.01).Conclusion:As2 O3 can reverse the drug resistance of HepG2/ADM cells,its mechanism may be related to inhibition of cell proliferation,promotion of apoptosis,down-regulation of the expression levels of Notch-1,Hes-1,MDR (P-gp),Bcl-2 and up-regulation of the expression levels of Bax mRNA and protein.