低剂量电离辐射对7721细胞细胞周期及p53、Ku70和Ku80表达的影响

目的　观察电离辐射对 772 1细胞 (人肝癌细胞 )细胞周期和p53、Ku70和Ku80基因表达的影响。方法　以人肝癌细胞株 772 1为研究对象 ,通过克隆形成实验拟合出 772 1细胞的剂量存活曲线 ;用流式细胞技术检测 75mGyX射线照射后 772 1细胞周期变化 ;用原位杂交方法检测 772 1细胞p53、Ku70和Ku80基因在 75mGyX射线照射前、后的表达情况。结果　与对照组相比 ,75mGyX射线照射后 0 5～ 6h ,772 1细胞S期延长 (P <0 0 5)。p53、Ku70和Ku80基因的表达照射前与照射后比较差异无显著性。结论　 772 1细胞在 75mGyX射线照射后 ,未出现G1期阻滞 ,p53、Ku70和Ku80基因在照射前、后表达无明显变化 ,是由于这些基因自身存在缺陷或激活机制存在缺陷所致

The effect of ionizing radiation on expression of DNA repair genes and cell cycle progression of human liver cancer cells

Objective To investigate the effect of ionizing radiation on the expression of p53,Ku70 an d Ku80 genes and the cell cycle progression of 7721 cell. Methods Dose-survival curve of 7721 cells was figured by colony-forming assay.7721 cells were irradiated with X-rays at the dose of 75 mGy a nd the cells were collected at different times after irradiation.Cell cycle was a nalyzed by FACS and the expressions of p53,Ku70 and Ku80 genes were detected by in situ hybridization. Results The S phase of 7721 cells was prolonged after 75 mGy X-r ay irradiation compared with that of the control group (P<0 01).There was n o change in the expression of p53,Ku70 and Ku80 genes after irradiation. Conclusion There is no G-1 arrest effect of radiation at low dose on 7721 cells.The expressions of p53,Ku70 and Ku80 are not influenced by radiat ion.;