全反式维甲酸诱导大鼠C6脑胶质瘤细胞凋亡的实验研究

Apoptosis Induced by All-trans Retinoic Acid in Rat C6 Glioma Cells

目的:探讨全反式维甲酸对大鼠C6脑胶质瘤细胞的增殖抑制及其分子机制。方法:MTT法检测全反式维甲酸作用于大鼠C6脑胶质瘤细胞后,观察其对细胞增殖抑制率的影响。流式细胞仪观察肿瘤细胞周期及凋亡率的变化。电镜观察C6细胞超微结构变化。Western blot法在不同时间点对凋亡相关基因caspase-3活性蛋白产物的表达进行了检测。结果:MTT结果表明ATRA对C6细胞的抑制作用具有时间和浓度依赖性。流式细胞仪检测证明与对照组相比,处理组C6细胞发生G1期阻滞;S、G2期细胞比例下降;细胞出现亚二倍峰,凋亡比例明显增加。电镜下全反式维甲酸作用72h后处理组C6细胞呈凋亡改变:如核固缩、染色质趋边凝聚。Western blot检测发现,处理组出现了caspase-3蛋白活性裂解片段。结论:全反式维甲酸抑制C6脑胶质瘤细胞生长,全反式维甲酸抑制脑胶质瘤的作用机理可能至少通过改变细胞周期分布、诱导凋亡来实现。

Objective： To observe the inbibitory effec.t of all-trans retinoie acid （ATRA） on the growth of rat C6 glioma cells and to explore the underlying molecular mechanisms. Methods： MTF assay was employed to detect the growth of rat C6 glioma cells treated with ATRA and the inhibition rate was evaluated. Flow cytometry was used to determine the cell cycle distribution and the rate of apoptosis. The ultramicroscopic structure of C6 cells was observed through transmission electrun microscopy. Westeru blot was performed to analyze the expression of caspase-3 proteins in the treated and unlreated ral C6 glioma cells. Results： MTT assay results showed that the inhibitory effect of ATRA on the growth of rat C6 glioma cells was dose-dependent and time-dependent. According to the flow cytometry analysis, C6 ceils were attested in G1 phase. The proportion of cells in S and G2 phase was decreased. A typical subdiploid peak was detected in DNA frequency distribution histograms. Signs of apoptosis-like condensation of nuclei and margination of nuclear chromatin were observed at 72 hours after the cells were treated with ATRA. Western blot indicated that rat C6 glioma cells treated with ATRA presented with increased expression of easpase-3 active proteins. Conclusion： ATRA inhibits the growth of rat C6 glioma cells, and its molecular mechanism may inwolve its induction of changes in cell cycle distribution and apoptosis.