伽玛射线诱导脑膜瘤细胞凋亡和影响原癌基因c-myc的表达

Effects of gamma-ray on apoptosis and expression of c-myc protooncogene of meningioma cells

目的 观察不同剂量伽玛（γ）射线诱导脑膜瘤细胞凋亡和原癌基因c-myc表达变化.方法 采用机械分离法获得稳定生长脑膜瘤细胞的离体培养细胞株,根据不同照射剂量分为4组,照射组分别接受中心剂量为2.00、5.00、8.22、13.33 Gy,设立对照组,剂量为0,照射后荧光显微镜观察细胞形态变化,流式细胞术检测细胞周期和凋亡率,Westem blot法检测c-myc蛋白的表达变化.结果 对照组、照射1组、2组、3组及4组细胞凋亡率分别为：（3.73±0.25）％、（4.07±0.29）％、（9.81±1.66）％、（21.63±3.08）％、（8.27±1.61）％；c-myc蛋白表达分别为：0、11±0.01、0.12±0.01、0.19 ±0.02、0.31±0.08、0.09±0.01;对照组和中心剂量2 Gy组照射后细胞形态、细胞周期、凋亡率和c-myc蛋白表达差异无统计学意义（P＞0.05）；中心剂量分别为5.00 Gy和8.22 Gy组细胞出现凋亡特征,细胞周期G0/G1和G2/M期细胞数量逐渐增多,细胞凋亡率升高,c-myc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组,细胞以坏死为主,S期细胞增多,c-myc蛋白表达减少.结论 一定剂量的伽玛刀射线能够诱导脑膜瘤细胞进入凋亡,原癌基因c-myc在此过程中可能发挥促进脑膜瘤细胞进入凋亡过程.

Objective To investigate the apoptosis of meningioma cell and changes of the expression of c-myc protooncogene after gama ray radiation.Methods The isolated and cultured meningioma cells with stable growth were obtained from a patient with meningiomas by mechanical separation,and those cells were divided into 4 groups with the radiation center doses of 2.00,5.00,8.22,and 13.33 Gy respectively.There was a control group without radiation.Meningioma cell morphology was observed under fluorescent microscope.Flow cytometry was used to examine the cell cycle and apoptosis.The expression of c-myc protein was detected by using Western blotting.Results The cell apoptosis rate in contol group,and radiation 2.00,5.00,8.22 and 13.22 Gy groups was respectively （3.73 ± 0.25） %,（4.07 ± 0.29） %,（9.81 ± 1.66）%,（21.63 ±3.08）% and （8.27 ± 1.61）%.Ehe expression of c-myc protein in contol group,and radiation 2.00,5.00,8.22 and 13.22 Gy groups was respectively 0.11 ± 0.01,0.12 ± 0.01,0.19 ±0.02,0.31 ±0.08 and 0.09 ±0.01.There was no significant difference in the cell morphology,cell cycle,apoptosis and the expression of c-myc protein between control group and irradiation 2.00 Gy group.Characteristics of apoptosis were found in radiation 5.00 Gy and 8.22 Gy groups,and the number of cells in G0/G1 and G2/M phases was gradually increased as well as the apoptosis rate,and the c-myc protein expression increased （P 〈 0.05） in radiation 5.00 and 8.22 Gy groups vs.control group.In irradiation 13.33 Gy group,necrosis was found widely,the number of cells in S phase was increased and the expression of c-myc protein decreased.Conclusion The apoptosis of meningioma cells could be induced by appropriate gamma ray dose.In this process,the c-myc proto-oncogene may promote the apoptosis of meningioma cells.