三氧化二砷对肝癌HepG2细胞凋亡及Bcl-2、Bax表达的影响

目的探讨三氧化二砷(As2O3)对人肝癌细胞系HepG2的凋亡诱导作用及其发生机制。方法体外培养HepG2细胞,用不同浓度的As2O3对HepG2细胞进行干预;采用MTT、Annexin V/PI双染及TUNEL法,观察其对HepG2细胞的增殖抑制和凋亡诱导作用;采用流式细胞术定量检测凋亡相关蛋白Bcl-2与Bax表达的变化。结果 As2O3在体外能明显抑制HepG2细胞生长,具有时间剂量依赖关系。Annexin V/PI双染及TUNEL法结果显示:5～20μmol/L的As2O3作用24h均可诱导HepG2细胞凋亡,且呈剂量依赖性,差异均有统计学意义(t分别=-2.96、-4.15、-7.33,P均<0.05);As2O3作用HepG2细胞24h时Bcl-2表达下降,Bax表达上升,Bcl-2/Bax比值降低,呈剂量依赖性,差异均有统计学意义(t分别=3.59、5.65、6.94、7.62、7.92,P均<0.05)。结论一定浓度的As2O3能抑制HepG2细胞增殖,促进其凋亡,其机制可能与调控Bcl-2、Bax表达有关。

Influence of arsenic trioxide on apoptosis and Bcl-2/Bax expression of hepatoma cell line HepG2

Objective To investigate the apoptosis inducing activity of arsenic trioxide in hepatoma cell line HepG2 and its mechanisms.Methods HepG2 cells were treated with arsenic trioxide at 1.25,2.5,5,10,20μmol/L.Cell growth inhibitory rate was detected by MTT colorimetric assay every 24 hours.Apoptosis rate was analyzed by Annexin V/PI fluorescence staining and TUNEL.Changes in expression of Bcl-2 and Bax protein were assayed by flow cytometry.Results MTT tests showed HepG2 cell proliferation was significantly inhibited by arsenic trioxide in time and dosedependent fashion.Marked apoptosis was detected by Annexin V/PI and TUNEL in HepG2 cells after treatment by arsenic trioxide at 5,10,20μmol/L after 24 hours and increased in a dose-dependent manner（t=-2.96,-4.15,-7.33,P 0.05）.The Bcl-2 expression decreased and the Bax expression increased in HepG2 cells induced by arsenic trioxide after 24 hours （t=3.59,5.65,6.94,7.62,7.92,P0.05）.Conclusions Bcl-2 and Bax protein probably correlated with the activation of apoptosis in HepG2 cells induced by arsenic trioxide.