MCPH1在DNA损伤应答中的作用

摘要

Objective To discover the role of MCPH1 in DNA double-strand damage induced by ionizing radiation and its relationship with H2AX in esophageal cancer cell ECA109. Methods ECA109 cancer cells accepted 8 Gy 1 h after irradiation were collected for protein extraction and immunofluorescence then MCPH1 and H2AX protein expression and nuclear foci changes were observed. A stable low expression of H2AX cell lines was established and MCPH1 and H2AX protein expression and nuclear foci changes induced by ionizing radiation after silence H2AX were detected. Results (1)A stable low expression of H2AX cell lines in ECA109 cells was successfully constructed. (2)Ionizing radiation could cause the increase of r-H2AX and MCPH1 protein expression, as the same as nuclear focus increase of r-H2AX and MCPH1. (3)The protein level and nucleus focus of r-H2AX and MCPH1 were significantly reduced in ECA109 after silence H2AX. Conclusion MCPH1 is the part of DNA damage response triggered by ionizing radiation and is located in damage response downstream and can be regulated by H2AX.%目的：研究食管癌 ECA109细胞中 MCPH1在电离辐射诱导的 DNA 双链损伤中的作用以及与H2AX 的关系。方法：将食管癌 ECA109细胞接受8 Gy 照射后1 h 提取蛋白并进行免疫荧光检测，观察MCPH1与H2AX的蛋白表达情况及核内斑点的变化。建立稳定低表达H2AX的食管癌ECA109细胞株，检测沉默H2AX 后电离辐射导致的MCPH1与H2AX的蛋白表达情况及核内斑点的变化。结果：（1）成功建立了稳定低表达H2AX 的食管癌细胞株。（2）电离辐射可以诱导r-H2AX 与MCPH1蛋白水平增加，同时可引起r-H2AX 与MCPH1核内斑点增多。（3）低表达H2AX 的ECA109细胞中，电离辐射诱导的 r-H2AX 与MCPH1蛋白增高水平下降，核内斑点减少。结论：MCPH1参与到电离辐射诱导的DNA双链损伤中，并且它的位置位于H2AX 的下游，被H2AX调控。