替莫唑胺对人脑胶质瘤细胞U251增殖、凋亡的影响及其机制探讨

Effects of temozolomide on proliferation and apoptosis of human glioma cells U251

目的观察替莫唑胺对人脑胶质瘤细胞U251增殖、凋亡的影响,并探讨其可能机制。方法取对数生长期U251细胞,分别加入0.02、0.06、0.1 g/L替莫唑胺,空白对照组不加替莫唑胺,分别培养24、48、72 h,MTT实验观察细胞增殖情况;取对数生长期U251细胞,加入0.06 g/L替莫唑胺(0.06 g/L替莫唑胺组),细胞培养48 h后,用流式细胞技术测算细胞凋亡率,RT-PCR法、Western blotting法检测存活素(Survivin)mRNA、蛋白。结果随着替莫唑胺浓度增加及作用时间延长,U251细胞增殖抑制率越高。0.06 g/L替莫唑胺组细胞凋亡率为22.6%±2.3%,对照组为3.3%±1.1%,两组比较,P<0.05;0.06 g/L替莫唑胺组Survivin mRNA相对表达量为0.65±0.11,对照组为0.96±0.15,两组比较,P<0.05;0.06 g/L替莫唑胺组Survivin蛋白相对表达量为0.25±0.03,对照组为0.49±0.04,两组比较,P<0.05。结论替莫唑胺能有效抑制U251细胞增殖,诱导细胞凋亡,其机制可能与抑制Survivin表达有关。

Objective To observe the effects of temozolomide on the proliferation and apoptosis of human glioma cells U251 and to explore its possible mechanism. Methods U251 cells in the logarithmic growth phase were selected and then were added with 0. 02,0. 06,0.1 g/L temozolomide, but the cells in the blank control group were not given. These cells were cultured for 24, 48 and 72 h, respectively. MTT was applied to observe the cell proliferation. U251 cells in the loga- rithmic growth phase were selected, and then were added with 0.06 g/L temozolomide （ as the 0.06 g/L temozolomide group）. After U251 cells were cultured for 48 h with different concentrations of temozolomide, flow eytometry was used to determine the apoptosis rate, and RT-PCR and Western blotting were used to detect the expression level of survivin mRNA. Results The cellular proliferation inhibition rate of U251 cells increased over the time and the increased concentrations of temozolomide. The apoptosis rates of the O. 06 g/L temozolomide group and the control group were 22.6% - 2.3% and 3.3% - 1.1%, respectively; the relative expression of survivin mRNA was 0.65 - 0. 11 in the 0.06 g/L temozolomide group, and was 0.96 - 0.15 in the control group ; the expression of survivin protein was 0.25 - 0.03 in the 0.06 g/L temo- zolomide group, and was 0.49 - 0.04 in the control group ; the differences were significant between these two groups, all P 〈 0.05. Conclusion Temozolomide can effectively inhibit the proliferation of U251 ceils and induce the apoptosis by in- hibiting the survivin expression.