伽玛射线对人垂体瘤细胞细胞周期和抑癌基因p16表达的影响

摘要

Objective: To investigate the change of human pituitary tumor cell cycle and the p16 tumor suppressor gene expression after Gamma knife radiation. Methods: The primary pituitary tumor cells with stable growth were gained from a patient of pituitary tumor by mechanical separation, and were divided into 4 groups with the radiation center dose 2,5,8.22,13.33 Gy respectively. There was the control group without radiation. Flow cytometry was used to detect the cell cycle and apoptosis. The expression of p16 protein were detected by Western Blot. Results: There was no significant difference for cell cycle, apoptosis and the expression of c-myc protein between the control group and the irradiation group with 2 Gy of center dose. Compared with the control group, the cell number of G0/G1 and G2/M phases from the irradiation groups with 5 Gy and 8.22 Gy of center dose were gradually increased, as well as the apoptosis rate increased, and p16 protein expression were increased (P＜0.05). There were the S phase cells increased and the expression of p16 protein decreased for the irradiation goups with 13.33 Gy of center dose. Conclusion: Pituitary tumor cells could be induced to the change of cell cycle and apoptosis under the appropriate gamma ray dose. p16 tumor suppressor gene may play in this process to promote the process of pituitary tumor cells into apoptosis.%目的:探讨不同剂量伽玛(γ)射线影响人垂体瘤细胞细胞周期和抑癌基因p16表达的变化.方法:采用机械分离法获得稳定生长垂体瘤原代培养细胞株,根据不同照射剂量分为4组照射组,分别接受中心剂量为2、5、8.22、13.33 Gy,设立对照组,剂量为0,照射后用流式细胞术检测细胞周期和凋亡率,Western Blot法检测p16蛋白的表达变化.结果:对照组和中心剂量2 Gy照射后细胞周期、凋亡率和c-myc蛋白表达无明显差异;中心剂量分别为5 Gy和8.22 Gy时细胞周期Go/G1和G2/M期细胞数量逐渐增多,细胞凋亡率升高,p16蛋白表达增多,与对照组比较,差异均有统计学意义(P＜0.05);剂量为13.33 Gy时,S期细胞增多,p16蛋白表达减少.结论:一定剂量的伽玛射线能够改变细胞周期,促进垂体瘤细胞进入凋亡,抑癌基因p16在此过程中可能发挥促进垂体瘤细胞进入凋亡过程.