【摘要】 目的探讨60Coγ射线照射前、后,BRCA1、RAD51蛋白在GM、ATM+-AT、AT细胞中的表达。方法应用免疫荧光染色和激光扫描共聚焦显微镜,观察GM、ATM+-AT、AT细胞在0和10Gy60Coγ射线照射后,BRCA1、RAD51蛋白在上述细胞中的定位及表达并进行定量分析。结果60Coγ射线照射前,BRCA1、RAD51蛋白在GM、ATM+-AT、AT细胞中仅有少量表达并且无共定位表达,其中在AT细胞中表达量最低;10Gy60Coγ射线照射后,BRCA1、RAD51在GM、ATM+-AT、AT细胞中表达量增高,其中GM、ATM+-AT细胞呈现共定位表达,AT细胞无共定位表达;GM、ATM+-AT细胞中BRCA1、RAD51蛋白表达量与AT细胞比较差异有统计学意义(P<0·01);GM细胞中BRCA1、RAD51蛋白表达量与ATM+-AT细胞比较差异也有统计学意义(P<0·01)。结论GM细胞和ATM+-AT细胞中存在ATM基因,ATM在射线等因素诱导下可以激活其下游基因BRCA1、RAD51,并且使这两种蛋白表达或表达量增加并且相互作用,共同完成辐射损伤后的细胞修复;外源性ATM转入正常GM细胞后,由于外源性的ATM基因不能完全弥补内源性的ATM突变基因的功能,对其下游基因Brca1“部分”磷酸化,表现为BRCA1、RAD51蛋白表达量均较GM细胞低。更多还原

【Abstract】 ObjectiveTo investigate the expressions of BRCA1 and RAD51 proteins in GM, ATM~+-AT, and AT cells before and after irradiation by ~ 60 Co γ-rays. MethodsThe localizations and expressions of BRCA1 and RAD51 proteins in GM, ATM~+-AT, AT cells were detected by immunofluorescence staining and laser scanning confocal microscopy after 0 and 10 Gy ~ 60 Co γ-ray irradiation. Quantitative analysis was also processed on these proteins. Results Before irradiation with γ-rays, few expression of RAD51 or BRCA1 protein and no colocalization was observed in GM, ATM~+-AT, AT cells, and lowest expression in AT cells. Being irradiated with 10 Gy ~ 60 Co γ-rays, the expressions of BRCA1 and RAD51 proteins were increased in GM, ATM~+-AT, and AT cells. Colocalized expressions in GM, ATM~+-AT cells were observed, but no such expression in AT cells. The expressions of BRCA1 and RAD51 proteins in GM, ATM~+-AT cells statistically significantly differed from those in AT cells (P<0.01). The difference of the expression of BRCA1 and RAD51 proteins between GM cells and ATM~+-AT cells was also statistically significant (P<0.01). Conclusions After induction by irradiation, ATM gene that exists in GM and ATM~+-AT cells could activate its down stream genes, BRCA1 and RAD51, and could enhance the expressions of and interactions between these two proteins. All these changes are helpful for cell repair following radiation injury. The expressions of BRCA1 and RAD51 proteins were lower in normal GM cells transfected with extrinsic ATM than that in GM cells because the extrinsic ATM gene could not completely compensate the function, partial phosphorylation of down stream gene BRCA1, of intrinsic ATM mutative gene.更多还原