CP466722抑制HepG2细胞增殖并诱导细胞凋亡

目的:研究共济失调毛细血管扩张症突变蛋白(ATM)抑制剂CP466722对人肝细胞癌HepG2细胞增殖和凋亡的影响及其可能的分子机制。方法:MTT法检测CP466722对HepG2细胞活力的抑制作用,细胞集落形成实验观察CP466722对细胞增殖的影响,流式细胞术分析细胞周期的变化,TUNEL染色观察CP466722对细胞凋亡诱导作用,Western blotting检测细胞内蛋白的表达水平。结果:CP466722能够剂量依赖性地抑制HepG2细胞活力与细胞增殖;HepG2细胞经CP466722作用24 h后,细胞周期明显阻滞于G_2/M期,同时磷酸化细胞分裂周期蛋白2(p-Cdc2)、细胞分裂周期蛋白25 C(Cdc25C)和磷酸化Cdc25C(p-Cdc25C)的蛋白水平下降,而p27的蛋白表达则上调。较高浓度的CP466722诱导HepG2细胞发生凋亡,促进胱天蛋白酶3(caspase-3)和多腺苷二磷酸核糖聚合酶(PARP)的剪切。此外,CP466722抑制β-联蛋白(β-catenin)及其下游因子生存素(survivin)的表达,上调p38丝裂原活化蛋白激酶(p38 MAPK)的磷酸化水平。结论:CP466722抑制HepG2细胞增殖并诱导细胞发生凋亡,其机制可能与其抑制β-catenin信号途径和激活p38 MAPK相关。

CP466722 inhibits proliferation and triggers apoptosis of HepG2 cells

AIM: To investigate the effect of CP466722, an inhibitor of ataxia telangiectasia mutated protein (ATM), on the proliferation and apoptosis of human hepatocellular carcinoma HepG2 cells. METHODS: The cell viability was detected by MTT assay. The cell growth inhibition was measured by colony formation assay. The effect of CP466722 on the cell cycle distribution of the HepG2 cells was examined by flow cytometry. The cell apoptosis was analyzed by TUNEL staining. The protein expression was examined by Western blotting. RESULTS: CP466722 inhibited the cell viability and cell proliferation in a dose-dependent manner. In CP466722-treated HepG2 cells, the cell cycle was arrested in G₂/M phase, and the protein levels of phosphorylated cell division cycle protein 2 (p-Cdc2), cell division cycle protein 25C (Cdc25C) and phosphorylated Cdc25C (p-Cdc25C) were inhibited, whereas the protein expression of p27 was up-regulated. CP466722 triggered the apoptosis of HepG2 cells through cleavages of caspase-3 and poly (ADP-ribose) polymerase (PARP). In addition, CP466722 increased the phosphorylation of p38 mitogen-activated protein kinase (p38 MAPK) and suppressed the expression of β-catenin and survivin in the HepG2 cells. CONCLUSION: CP466722 inhibits the proliferation and induces the apoptosis of HepG2 cells, which may be related to activating p38 MAPK and inhibiting the expression of β-catenin and survivin.