DNA—PKcs在细胞辐射超敏感性中的作用研究  

DNA-PKcs functions in cellular hyper-radiosensitivity

作　　者：马季[1] 叶才勇[2] 丁楠[2] 朱佳赟[2] 胡文涛 Ma Ji;Ye Caiyong;Ding Nan;Zhu Jiayun;Hu Wentao(School of Radiation Medicine and Protection,Medical College of Soochow University,Suzhou 215123,China（Ma J,Hu WT;Department of Space Radiobiology,Institute of Modern Physics,Chinese Academy of Sciences,Lanzhou 730000,China（Ye CY,Ding N,Zhu JY)

机构地区：[1]苏州大学医学部放射医学与防护学院,215123 [2]中国科学院近代物理研究所空间辐射生物研究室,兰州730000

出　　处：《中华放射医学与防护杂志》2018年第7期489-493,共5页Chinese Journal of Radiological Medicine and Protection

基　　金：国家自然科学基金（11405235）

摘　　要：的 研究DNA-PKcs在细胞辐射超敏感性中的作用。方法 X射线照射M059K和M059J细胞后，克隆形成法实验检测其存活分数；微核分析法和γ-H2AX焦点形成实验检测DNA损伤；Western blot实验检测M059K，M059J细胞中磷酸化Chk1、Chk2和总Chk1、Chk2蛋白的表达。结果 在X射线照射剂量〈1 Gy时，M059K细胞呈现出辐射超敏感性；DNA损伤水平不能用于表征低剂量区的HRS/IRR；0.2 Gy X射线照射后，M059K细胞中pChk1/Chk1在20-60 min内显著高于M059J细胞（t=14.157、13.661、14.177、11.317、14.512， P〈0.05）；0.2 Gy X射线照射后，M059K细胞中pChk2/Chk2在20-50 min内显著高于M059J细胞（t=13.182、13.868、14.155、14.477， P〈0.05）。结论 DNA-PKcs野生型的人胶质瘤M059K细胞中存在着低剂量辐射超敏感性现象，其发生可能与DNA-PKcs介导的G2/M期检验点相关蛋白激活有关。Objective To explore the functions of DNA-PKcs in cellular low dose hyper-radiosensitivity. Methods Colony-formation assay was used to detect the survival fractions of M059K and M059J cell lines treated by X-ray irradiation. Micronucleus assay and γ-H2AX foci assay were used to measure the radiation-induced DNA damage. Western blot was used to detect the relative expression levels of phospho-Chk1, total Chk1, phospho-Chk2 and total Chk2 of M059K and M059J cells. Results The hyper-radiosensitivity was observed in M059K cells irradiated with X-ray of doses lower than 1 Gy. DNA damage levels did not show HRS/IRR in the cell lines we used. pChk1/Chk1 in M059K cells was significantly increased during 20 min to 60 min after 0.2 Gy X-ray irradiation （t=14.157, 13.661, 14.177, 11.317, 14.512, P〈0.05）; pChk2/Chk2 in M059K cells was markedly increased during 20 min to 50 min after 0.2 Gy X-ray irradiation （t=13.182, 13.868, 14.155, 14.477, P〈0.05）. Conclusions M059K cells show the phenomenon of low dose hyper-radiosensitivity, which may be related to activation of proteins in G2/M phase checkpoints regulated by DNA-PKcs.

关 键 词：肿瘤细胞 低剂量辐射超敏感性 细胞周期检测点激酶2 DNA依赖蛋白激酶催化亚基 

分 类 号：R146[医药卫生—公共卫生与预防医学]