硝普钠诱导胶质瘤细胞株U251细胞凋亡的研究

Study of apoptosis of glioma cells line U251 cells induced by sodium nitroprusside

目的探讨一氧化氮(NO)供体药物硝普钠(SNP)对胶质瘤细胞株U251细胞凋亡诱导效应及其机制。方法以0.2、0.5、1.5和2.0mmol/L浓度SNP作用于U251细胞24h,甲基噻唑基四唑法检测U251细胞生长抑制率,Griess法检测其NO含量,流式细胞术检测其凋亡率,免疫印迹法检测SNP作用24h前后B淋巴细胞瘤-2基因(Bcl-2)、天冬氨酸特异性半胱氨酸蛋白酶3(caspase-3)在U251细胞的表达。结果不同浓度SNP对U251细胞生长均有抑制作用(P<0.01),且随SNP浓度升高而增强(P<0.01)。U251细胞内NO含量随SNP浓度升高递增(P<0.01),并与细胞生长抑制率的呈正相关(P<0.01)。不同浓度的SNP均能诱导U251细胞凋亡,且随浓度升高而增强(P<0.01)。随SNP浓度升高U251细胞Bcl-2表达减少,caspase-3表达增加(P<0.05)。结论 SNP可抑制U251细胞生长并诱导其凋亡,其生长抑制效应可能与NO浓度有关,凋亡诱导作用与U251细胞Bcl-2下调和caspase-3上调有关。

Objective To investigate the effect of sodium nitroprusside（SNP） on glioma cell line U251 cells apoptosis and its mechanism. Methods U251 ceils were cultured in the media containing SNP of the different concentrations. The rates of the inhibition of U251 cells growth induced by SNP were detected by MTT assay. Nitie oxide （NO） concentration in U251 cells was determined by Griess method. The rate of U251 cells apoptosis was detected by flow cytometry. The expression of Bel-2 and caspase-3 were detected by western blot in U251 cells before and after the treatment with SNP. Results The significantly inhibitory effects of the different concentration SNP on U251 cells were observed （P〈0.01） and they were SNP dose-dependent. The NO concentration rose with the increase in SNP concentration. There was significantly positive correlation between the inhibitory rate and NO concentration （P〈0.01）. The apoptotic rates of U251 cells in 0.5 mmol/L, 1.0 mmol/L and 20 mmol/L SNP groups were 15.25%, 20.56% and 40.73% respectively and they were significantly higher than that （5.04%） in the control group. The apoptotic effects of SNP on U251 cells were SNP dose-dependent （P〈0.01）. The expression level of Bcl-2 was significantly lower and the expression level of caspase-3 was significantly higher in all the experiment groups than those in the control group （P〈0.05）. The levels of Bcl-2 expression were negatively related and the levels of caspase-3 expression were positively related to SNP concentration （P〈0.05）. Conclusions SNP can inhibit the growth and induce apoptosis of U251 cells. The effect of SNP on of U251 cells growth may be related to NO released by SNP and the apoptotic effect of SNP on U251 cells may be related to the SNP-induced down-regulation of Bcl-2 and up-regulation of caspase-3 in of U251 cells.