电离辐射对食管癌细胞周期及MDC1、53BP1蛋白表达的影响

目的 观察60Co γ射线照射后食管癌细胞周期、细胞凋亡及其相关蛋白表达的变化，为食管癌放射治疗、靶向治疗提供理论依据。方法 食管癌细胞株TE 13进行不同剂量（0、1、2、5、10、15Gy）照射后，应用流式细胞术分别检测照射后1、2、12、24和48h细胞周期和凋亡指数的变化；同时采用Western blot方法检测MDC1和53BP1蛋白表达情况。结果 TE 13细胞照射后12、24、48h，TE 13细胞的G0/G1期、G2/M期和S期的变化呈现明显剂量依赖性，1Gy和2Gy照射后12h，细胞G2/M期阻滞开始出现；5、10、15Gy照射后24h，细胞G2/M期阻滞最为明显，与对照组（0Gy组）相比，差异具有统计学意义（P<0.05）；15Gy照射后12h、24、48h，TE 13细胞的凋亡增加非常显著（P<0.01）；不同剂量照射后1、2、24h，TE 13细胞MDC1和53BP1蛋白表达未见明显变化（P>0.05）。结论 TE 13细胞经不同剂量放射线照射后，细胞周期出现明显的G2/M期阻滞，细胞凋亡指数明显增加，但对MDC1和53BP1蛋白表达未见明显影响。

Effects of Irradiation on Cell Cycle and Expression of MDC1 and 53BP1 in Esophageal Carcinoma Cells

Objective 　To investigate changes of cell cycle , apoptosis and protein expression in esophageal carcinoma cells after 60 Coγ2rays irradiation , it is the basis as combing target t reatment and radiotherapy for esophageal cancer. Methods 　Using flow cytomet ry ( FCM) to check the percentage of different phase cells and apoptosis at 1 , 2 , 12 , 24 , 48 h af ter irradiation (0 ,1 ,2 ,5 ,10 ,15 Gy) . Expression of MDC1 and 53BP1 were detected by Western blot af ter irradiation. Results 　The percentage of G0 / G1 , G2 / M and S phase of TE213 cells was changed dependence on doses increasing of irradiation. At 12 h af ter irradiation with 1 Gy and 2 Gy , arrest of G2 / M stage was gradually increased and reached the peak at 24 h af ter irra2 diation with 5 ,10 ,15 Gy ( P < 0. 05) . Apoptotic index of TE213 cell was obviously elevated at 12 h ,24 h and 48 h af ter irradiation with 15 Gy ( P < 0. 01) . However , expression of MDC1 and 53BP1 proteins in TE213 cells were no significant changes at 48 h af ter irradiation with 5 ,10 ,15 Gy ( P > 0. 05) , compared with the cont rol group . Conclusion 　G2 / M arrest and apoptosis of TE213 cells were remarkable increas2 ing af ter different doses irradiation. Meanwhile , No changes of expression of MDC1 and 53BP1 proteins in TE213 cells were investigated af ter irradiation.