DNA聚合酶β在食管癌组织中的修复功能  

DNA repair function of DNA polymerase β in human esophageal cancer

作　　者：赵四敏[1] 陈旭东[2] 张成娟[3] 赵国强[4] 董子明[5] 

机构地区：[1]漯河医学高等专科学校病理生理学教研室,河南省漯河市462002 [2]漯河医学高等专科学校组织学与胚胎学教研室,河南省漯河市462002 [3]河南省肿瘤医院病理科,河南省郑州市450001 [4]郑州大学基础医学院微生物学与免疫学教研室,河南省郑州市450001 [5]郑州大学基础医学院病理生理学教研室,河南省郑州市450001

出　　处：《世界华人消化杂志》2010年第23期2460-2463,共4页World Chinese Journal of Digestology

基　　金：国家自然科学基金资助项目;No.30471952~~

摘　　要：目的:观察突变型DNA聚合酶β(DNA polymerase β,polβ)的碱基切除修复(base excision repair,BER)功能的改变.方法:将polβ真核表达载体pcDNA4-C-polβ1,pcDNA4-C-polβ2以脂质体介导方式转染polβ基因敲除的EC9706细胞,G418筛选得到稳定转染pcDNA4-C-polβ1,pcDNA4-C-polβ2的细胞克隆;通过镍柱亲和层析法纯化蛋白;退火合成含有单碱基缺失的DNA底物,与纯化的野生型和突变型polβ蛋白进行BER修复实验.结果:G418筛选得到稳定转染pcDNA4-C-polβ1,pcDNA4-C-polβ2的EC9706细胞;提取并纯化出polβ1、polβ2蛋白与退火合成单碱基缺口的DNA底物进行BER实验.在BER实验中,野生型polβ能够在DNA底物的酶切位点处将其完全切开,而突变型polβ仅将其部分切开.结论:野生型的polβ能够修复单碱基缺失的DNA底物,而突变型的polβ碱基切除修复功能明显减弱.AIM：To observe the variation in base excision repair（BER） function of mutant DNA polymerase β（polβ）.METHODS：The plasmids pcDNA4-C-polβ1 and pcDNA4-C-polβ2 were transfected into polβknockout EC9706 cells by lipotransfection.The stable transfectants were screened in the medium containing G418.The recombinant proteins were purified by nickel column chromatography.DNA substrate that contains a single-base deletion was synthesized to test the BER function of the purified recombinant proteins.RESULTS：Cell strains stably transfected with pcDNA4-C-pol β1 and pcDNA4-C-pol β2 were successfully obtained.Purified proteins polβ1 and polβ2 were incubated with synthesized DNA substrate that contains a single-base deletion to test their BER function.Wild-type polβ could completely excise the DNA substrate while the mutant polβ could only partly excise the DNA substrate.CONCLUSION：Wide-type polβ has stronger activity than mutant polβ in repairing DNA substrate that contains a single-base deletion.

关 键 词：DNA聚合酶Β 镍柱亲和层析 碱基切除修复 

分 类 号：R735.1[医药卫生—肿瘤]