中文摘要：

目的：探讨野生型DNA聚合酶β（polbeta）转染人食管癌Eca-109细胞后对其增变基因表型的效应。方法：将经过鉴定的重组pcDNA3.1质粒（插入野生型,wt）-polbeta转染培养的人食管癌Eca-109细胞。将Eca-109细胞分为3组：转染实验组（E）、空质粒转染对照组（C1）和未转染对照组（C2）。应用原位杂交技术显示wt-polbeta和wt-p53的杂交信号,免疫细胞化学染色显示POLB-免疫反应性（IR）和多药耐受（MDR1）-IR,免疫印迹显示wt-polbeta和突变（mt）-polbeta的带型,细胞化学技术检测各组细胞的增殖与分化细胞的比率。结果：polbeta免疫印迹结果显示E组呈现增强的wt-polbeta主带,C1、C2组呈现很弱wt-polbeta主带和显著突变的（mt）-polbeta主带（P〈0.01）;polbeta免疫细胞化学结果显示E组的强信号定位于细胞核内,C1、C2组信号皆很弱（P〈0.01）。E组的wt-polbeta及wt-p53原位杂交的信号强于C1、C2组（P〈0.01）。E组MDR1的免疫反应性和增殖与分化细胞的比率低于C1、C2组（P〈0.01）。结论：wt-polbeta转染的Eca-109细胞呈现wt-polbeta及wt-p53表达上调而mt-polbeta及MDR1表达下调的增变基因表型减弱。

英文摘要：

Aim： To explore the effects on polbeta-overexpressed human esophageal cancer Eca-109 cells transfected with wild type（wt）-polbeta.Methods：The identified recombinant pcDNA 3.1 was transfected into the Eca-109 cells,and the cultured cells were divided into 3 groups： transfected experimental group（E）,empty plasmid control group（C1）,and untransfected control group（C2）.The expressions of polbeta,p53,MDR1,and the ratio of proliferating/differentiated cells were detected by in situ hybridization,immunocytochemistry,immunoblotting,and cytochemisrtry techniques,respectively.Results： The immuoblotting showed that there was an enhanced band of wt-polbeta in E group,while a distinct major band of mt-polbeta in C1/C2 group（P〈0.01）.In polbeta immunocytochemistry the signals located in the nuclei were much stronger in E group than those in C1/C2 group（P〈0.01）.In situ hybridization the signals of wt-polbeta and wt-p53 located in the cytoplasm were markedly stronger in E group than those in C1/C2 group（P〈0.01）;whereas,the MDR1-immunoreactivity（IR） and the ratio of proliferating cells versus differentiated cells were much decreased in E group than those in C1/C2 group（P〈0.01）.Conclusion： In the transfected Eca-109 cells the expressions of wt-polbeta and wt-p53 are up-regulated and those of the mt-polbeta and MDR1 are down-regulated,which exhibites reduction of the mutator phenotype.