【摘要】 目的:探讨三氧化二砷(As2O3)对人神经胶质瘤细胞株U251的生长抑制作用及对基因表达和钙含量的影响。方法:MTT法观察As2O3对U251细胞的生长抑制作用;流式细胞仪测定不同浓度As2O3处理后U251细胞周期、增殖细胞核抗原(PCNA)、凋亡相关蛋白Fas和Bcl-2阳性细胞百分率及细胞内钙离子(IECa2+)含量变化。Annexin V-FITC+PI双参数检测细胞凋亡。结果:(1)As2O3可显著抑制U251细胞生长,且剂量-效应和时间-效应关系显著(P<0·05),其24h、48h和72h的IC50值分别为14·28μmol/L、13·63μmol/L和2·34μmol/L。(2)As2O3能显著增加Fas蛋白表达和IECa2+含量(P<0·01),下调PCNA蛋白表达(P<0·01),并使细胞周期阻滞在G2M期,但对Bcl-2表达无影响(P>0·05)。(3)U251细胞经As2O3处理后可出现凋亡。结论:As2O3在体外可显著抑制人神经胶质瘤U251细胞生长并引起凋亡,其机制可能与上调Fas表达和IECa2+含量、降低PCNA蛋白表达及阻滞细胞周期有关。更多还原

【Abstract】 AIM: To investigate the inhibitory effect of arsenic trioxide on human glioma cell line U251 growth, change of gene expression and intracellular calcium content. METHODS: MTT method was used to observe the growth inhibition effect. Cell cycle, positive rate of proliferation cell nuclear antigen （PCNA）, apoptosis associated protein Fas and Bcl-2, and intracellular calcium ion （IECa 2+ ） levels were measured by flow cytometry in U251 cells treated with different doses of As₂O₃. Apoptosis was detected with annexin V-FITC+PI dual parameter. RESULTS: As₂O₃ inhibited the growth of U251 cells dramatically. There were obvious dosage-effect and time-effect correlations （P<0.05）. The half inhibitory concentrations （IC 50 ） at 24 h, 48 h and 72 h were 14.28 μmol/L, 13.63 μmol/L and 2.34 μmol/L, respectively. As₂O₃ increased Fas protein expression and IECa 2+ levels, decreased PCNA protein expression in U251 cells （P<0.01）. It did not influence Bcl-2 protein expression （P>0.05）. The cell cycle was arrested in G₂M phase. Apoptosis occurred in U251 cells treated with As₂O₃ by annexin V-FITC+PI dual parameter detection. CONCLUSION: As₂O₃ inhibits the growth of U251 cells in vitro dramatically and induces apoptosis. The mechanism is probably associated with the improvement of Fas expression and IECa 2+ levels, decrease in PCNA protein expression and cell cycle arrest.更多还原