野生型INK4a/ARF基因共转染对A549细胞药物敏感性的影响

目的　研究野生型INK4a/ARF基因共转染对人肺腺癌A5 4 9细胞药物敏感性的影响。方法　利用阳离子脂质体介导的基因转染技术 ,将含有人全长野生型INK4a/ARF基因的真核表达重组质粒pcDNA3 p16 INK4a和pcDNA3 p14 ARF同时导入该基因位点缺失的人肺腺癌A5 4 9细胞系中 ,确定其编码的蛋白p16 INK4a和p14 ARF稳定表达 ;在设立空白组和空质粒转染组的情况下 ,用 5种不同作用机制的常用肺癌化疗药物 (阿霉素、顺铂、拓朴替康、诺维本和紫杉醇 )作用于转染前后的细胞 ,利用MTT法测定各种不同药物的 5 0 %抑制浓度(IC50 ) ,并测定在该浓度作用下转染细胞的凋亡指数。结果　转染INK4a/ARF基因后 ,A5 4 9细胞对阿霉素和顺铂的IC50 值显著降低 (P <0 0 5 ) ,而拓朴替康、诺维本和紫杉醇的IC50 值无明显变化 (P >0 0 5 ) ;阿霉素和顺铂诱导的凋亡指数也明显高于其他 3种药物。结论　恢复p16 INK4a和p14 ARF蛋白的表达可改变A5 4 9细胞对部分化疗药物的敏感性。

Effects of co-transfection of wild-type INK4a/ARF gene on the chemosensitivity of lung adenocarcinoma cell line A549

Objective To investigate the effects of co-transfection of the plasmid containing the wildtype (wt) INK4a/ARF gene on the chemosensitivity of human lung adenocarcinoma cell line A549. Methods Recombinant eukaryotic expression vectors pcDNA3-p16 INK4a and pcDNA3-p14 ARF were co-transfected into A549 cells by cationic liposome, in which the site of both genes was lost. By RT-PCR, immunocytochemistry and Western blotting analysis, G418 positive clone was obtained. The parental cell and negative control cell with plasmid pcDNA3-LacZ were used as controls. The 50% inhibition concentration (IC 50 ) of five commonly-used chemotherapy drugs and the apoptosis index (AI) of IC 50 were analysed respectively. Results Compared with the parental cells and negative control cells, the influence of the five drugs on IC50 was different. The values of IC 50 of doxorubicin and cisplatin decreased significantly but that of taxol, topotecan and vinorelbine remained unchanged. The apoptosis index of doxorubicin and cisplatin was much higher than that of other three drugs. Conclusion The chemosensitivity of a part of anti-cancer drugs could be changed by transfection of exogenous INK4a/ARF gene into lung adenocarcinoma cell A549.