外源野生型p53基因表达对人肺癌细胞药物敏感性影响

Effects of exogenous wild type p53 gene expression on s ensitivity to chem otherapeutic agents in human lung cancer cell

目的 了解外源野生型p5 3(wild typep5 3 ,wtp5 3)基因表达对人大细胞肺癌 80 1 D细胞对化疗药物敏感性的影响。方法 选用p5 3基因突变的人大细胞肺癌 80 1 D系。用脂质体介导构建的含wtp5 3基因载体转染 80 1 D细胞 ,PCR检测外源wtp5 3在宿主细胞存在情况 ,3H TdR掺入法测定 80 1 D细胞转染wtp5 3后药物敏感性变化 ,流式细胞仪 (FACS)分析细胞死亡情况。结果 转染wtp5 3在 80 1 D细胞有效表达 ,FACS分析转染细胞死亡率为 2 0 .1%。对多种抗癌药物筛选 ,转染wtp5 3细胞对顺铂和5 氟脲嘧啶敏感性分别提高 9.7和 11.4倍 ,对非DNA损伤制剂和其它DNA损伤制剂的敏感性无变化 ;DNA断裂电泳分析和形态学观察显示细胞呈坏死特征。结论 wtp5 3可选择性增加 80 1 D细胞对某些DNA损伤制剂的敏感性 ,其调节机制可能以非凋亡途径为主 。

Objective To investigate the effects of exogeno us wild type p53 (wtp53) gene expression on sensitivity to chemotherapeutic agents with different mec hanism of action in human lung cancer cells. WTHZ Methods A human lu ng cancer cells line 801 D with point mutation of p53 was transfected with eith er constructed recombinant plasmid pEGFP p53, which expressed wtp53 or pEGFP ve ctor. The expression of neo and wtp53 gene in anti G418 clone, 801 D vector an d 801 D wtp53, were detected by PCR. The functional activity of transfected wt p53 was demonstrated by partly 801 D apoptosis. 3 KG2 H TdR uptake assay was taken f or drug sensitivity measure according to standard procedures. Flow cytometry wa s employed to determine cell death. WTHZ Results Sensitivity of 801 D wtp53 to cisplatin and 5 fluorouracil was higher than that of 801 D vector by 9.7 and 11.4 fold respec tively. There was no significant difference for other DNA damaging agents and non DNA damaging ag ents, such as etoposide and adriamycin, vincristine and methylenum Caeruleum. An alysis of DNA ladder by gel electrophoresis and morphological observation showe d cell necrosis characteristics. WTHZ Conclusion 801 D cell line show s a selective sensitization to DNA damaging a gents when exogenous wtp53 is expressed. The increased sensitivity to cisplat in by exogenous wtp53 expression may be through non apoptosis pathway. This stu dy results provide experimental bases for comprehensive treatment of lung canc er.