目的：通过载体介导的shRNA下调BAG-1基因（Bcl-2 associated athanogene-1)表达，探讨其对肺癌A549细胞顺铂（cisplatin，DDP）耐药性的影响。方法：构建靶向BAG-1的shRNA干扰载体pGCsi-BAG-1，稳定转染A549细胞。实验组使用稳定转染pGCsi-BAG-1的细胞株（BAG-1-shRNA），阴性对照组使用无关序列质粒转染的细胞株（SC-shRNA），对照组使用未转染的亲本A549细胞株（Control）。Western blotting检测pGCsi-BAG-1转染对A549细胞BAG-1、Bcl-2表达的影响。MTT法、流式细胞术分别检测pGCsi-BAG-1转染对DDP处理后A549细胞的增殖和凋亡的影响。结果：成功构建稳定干扰BAG-1表达的A549细胞株，BAG-1-shRNA组细胞中BAG-1和Bcl-2蛋白表达显著低于SC-shRNA组和对照组（均P<0.05）。随DDP(25~40 μg/ml)浓度增加，各组细胞增殖抑制率也随之升高，DDP浓度为2.5 μg/ml时，BAG-1-shRNA组A549细胞的增殖抑制率即显著高于SC-shRNA组和对照组\[（22.26±4.89）% vs （10.07±3.82）%，（8.12±4.09）%，均P<0.05\]。与SC-shRNA组和对照组相比，DDP(2.5 μg/ml)处理24 h后，BAG-1-shRNA组凋亡率显著升高\[（37.8 4±3.62）％ vs （16.80±281）％、（17.10±3.11）％，P<0.05\]。结论：下调BAG-1表达可抑制DDP作用下的A549细胞的增殖并促进其凋亡。

Objective : To detect down regulation of the expression of  BAG-1 gene in lung cancer A549 by transfected a vector contained shRNA, and to investigate its effects on the cisplatin (DDP) resistance of A549 cells. Methods: Interference vector pGCsi-BAG-1 target BAG-1 was constructed and stable transferred into A549 cells. Cells stable transferred by pGCsi-BAG-1 were used as an experimental group (BAG-1-shRNA), cells transferred by non-sense vector were used as a negative control group (SC-shRNA), and the parent A549 cells were used as a control group. Western blotting was performed to detect the effect of pGCsi-BAG-1 transfection on the BCL-2 and BAG-1 expression of A549 cells. MTT method and flow cytometry was used to detect the influence on proliferation and apoptosis of A549 cells after DDP treatment. Results: An A549 cell line where  BAG-1 was stably interfered was successfully constructed. And the expression of BCL-2 protein in cells of the BAG-1- shRNA group was significantly lower than that of SC-shRNA group and the control group (all P<005). With increasing of the concentration of DDP, the proliferation inhibition rate of each cell was increased. When DDP concentration was 2.5 μg/ml, the cell proliferation inhibition rate of the BAG-1-shRNA group was significantly higher than that of SC-shRNA group and the control group (\[8.12±4.09\] % vs \[10.07± 3.82\] %, \[22.26±489\]%; all P<0.05). Compared with the SC-shRNA group and the control group, the apoptosis rate of the BAG-1-shRNA group was significantly increased after 24 h treatment with DDP (\[37.84±3.62\]% vs \[16.80±2.81\]%, \[1710±311\]%, P< 0.05). Conclusion: Down-regulation of  BAG-1 expression can inhibit the proliferation of A549 cells after DDP treatment and promote its apoptosis.

辽宁省科学技术计划立项课题资助项目（No. 2007225005-13）