ATM基因在低剂量电离辐射诱导EL-4细胞适应性反应中的作用

摘要

目的:探讨低剂量电离辐射诱导EL-4细胞适应性反应中ATM基因的作用.方法:EL-4细胞应用渥曼青霉素处理后接受低剂量0.075 Gy预先照射,再分别进行较高攻击剂量照射(1.0,1.5和2.0 Gy),RT-PCR和免疫荧光法检测ATM mRNA及蛋白表达.同时应用流式细胞术检测细胞凋亡和周期进程变化.结果:渥曼青霉素能够阻断ATM基因在mRNA及蛋白水平的表达.应用渥曼青霉素后直接接受攻击剂量照射和应用渥曼青霉素后先接受低剂量0.075Gy预先照射后再接受攻击剂量照射,均能诱导EL-4细胞发生适应性反应.结论:ATM基因可能不影响低剂量电离辐射诱导EL-4细胞发生适应性反应.%Objective: To investigate the effect of ataxia telangiectasia mutated gene ( ATM gene ) in the adaptive response ( AR ) induced by low dose ionizing radiation in EL - 4 cells. Methods: The ATM mRNA levels and protein expression of EL - 4 cells were detected by reverse transcription polymerase chain reaction ( RT - PCR ) and immumofluorescence method after the cells received the pre - exposure of 0.075 Gy X - rays ( inductive dose, D1 ) and the succeeding high dose irradiation ( challenge dose, D2; 1.0, 1.5, and 2.0 Gy X - rays, respectively ) with wortmannin ( inhibitor of ATM ). The apoptosis and cell cycle progression of EL -4 cells were detected with flow cytometry. Results: The expression of ATM mRNA and protein could be intercepted by wortmannin. Treatment with wortmannin in EL - 4 cells, and then challenged by high doses irradiation directly or received pre - exposure of low inductive dose and the succeeding challenge dose irradiation could induced the AR of EL - 4 cells. Conclusion: The AR induced by low dose ionizing radiation may be mediated without ATM gene in EL - 4 cells.