姜黄素通过下调P-糖蛋白和热休克蛋白70逆转耐热肝癌细胞的阿霉素耐受性(英文)

Curcumin Reverses Adriamycin-resistance of Thermotolerant Hepatocarcinoma Cells by Down-regulating P-glycoprotein and Heat Shock Protein 70

探讨姜黄素对耐热肝癌细胞(HepG2/TT)阿霉素耐受性的逆转作用及其机制.用MTT检测细胞活力,PI染色流式细胞术检测细胞凋亡,高效液相色谱法检测细胞内阿霉素的积累,Western blot检测细胞P-糖蛋白(P-glycoprotein,P-gp)、热休克蛋白70(heat shock protein 70,Hsp70)和caspase-3的表达.耐热肝癌细胞HepG2/TT能耐受阿霉素引起的细胞毒性和凋亡;姜黄素在5、10和20μmol/L时,能浓度依赖性地降低阿霉素对HepG2/TT细胞的IC50,增强阿霉素对HepG2/TT细胞的凋亡诱导作用.耐热肝癌细胞HepG2/TT与非耐热肝癌细胞HepG2比较,其P-gp和Hsp70的表达水平明显增高;10μmol/L姜黄素处理24 h后,HepG2/TT细胞P-gp和Hsp70的表达水平显著下降.HepG2/TT细胞内阿霉素的积累低于HepG2细胞;10μmol/L姜黄素处理3 h后,HepG2/TT细胞内阿霉素的积累明显增加.HepG2/TT细胞能抑制阿霉素激活caspase-3;10μmol/L姜黄素处理24 h后,阿霉素对HepG2/TT细胞caspase-3的激活作用增强.上述结果表明,姜黄素能逆转耐热肝癌细胞HepG2/TT的阿霉素耐受性,其机制可能与其下调P-gp和Hsp70的表达,进而促进阿霉素激活caspase-3有关.

The aim of this present work was to investigate whether curcumin reverses the adriamycin-resistance of thermotolerant hepatocarcinoma cell line and the underlying mechanisms.Cytotoxicity was evaluated by MTT assay.Apoptosis was determined by flow cytometer using propidium iodide staining.The accumulation of intracellular adriamycin was measured by high-performance liquid chromatography.The expressions of P-glycoprotein（P-gp）,heat shock protein 70（Hsp70）,and caspase-3 were analyzed by Western blotting.The thermotolerant hepatocarcinoma cell line HepG2/TT was resistant to adriamycin-induced cytotoxicity and apoptosis.Curcumin,at 5 μmol/L,10 μmol/L,and 20 μmol/L,decreased the IC50 of adriamycin to thermotolerant HepG2/TT cells and enhanced adriamycin-induced apoptosis in HepG2/TT cells in a concentration-dependent manner.The levels of P-gp and Hsp70 in HepG2/TT cells were obviously higher than that in HepG2 cells.Treatment with curcumin（10 μmol/L） for 24 h significantly reduced the levels of P-gp and Hsp70 in HepG2/TT cells.The accumulation of intracellular adriamycin in HepG2/TT cells was markedly lower than that in HepG2 cells and curcumin（10 μmol/L for 3 h） significantly increased the level of intracellular adriamycin accumulation in HepG2/TT cells.HepG2/TT cells obviously inhibited caspase-3 activation triggered by adriamycin,but co-treatment with 10 μmol/L of curcumin for 24 h significantly augmented the activation of caspase-3 in HepG2/TT cells treated with adriamycin.Curcumin overcomes the adriamycin-resistance of thermotolerant HepG2/TT cells by promoting adriamycin-triggered caspase-3 activation through down-regulating the activity and expression of P-gp and the expression of Hsp70.