中文摘要：

目的：研究同源重组修复基因RAD51对PTEN缺失小鼠胚胎成纤维细胞基因组稳定性的影响。方法：应用免疫荧光和中性单细胞电泳技术观察PTEN缺失后自发性和辐射诱导DNA双链断裂情况;并构建PTEN缺失细胞稳定转染RAD51的细胞系,γ射线照射后检测细胞存活率。结果：PTEN缺失导致细胞自发性和辐射诱导DNA双链断裂增多;转染RAD51后细胞存活率增高,辐射诱导的DNA双链断裂减少。结论：同源重组修复基因RAD51可以提高PTEN缺失细胞基因组稳定性。

英文摘要：

OBJECTIVE：To explore the effect of genomic stability of PTEN-deficient mice embryonic fibroblasts after transfection with RAD51,an important homologous recombination repair gene.METHODS： Immunofluorescence assay was used to observe the number of spontaneousγ-H2AX foci.Neutral single cell gel electrophoresis was applied to detect spontaneous and radiation-induced DNA double-strand breaks in both PTEN-deficient and PTEN wild-type cells.RESULTS：PTEN deletion led to an increase of spontaneousγ-H2AX foci and the length of tail moment,indicating DNA double-strand breaks.Transfection with RAD51 increased cell survival and decreased radiation-induced DNA double-strand breaks of PTEN-deficient cells.CONCLUSION：Homologous recombination gene RAD51 could increase genomic stability of PTEN-deficient cells.