Department of Respiratory Medicine, West China Hospital, Sichuan University, Chengdu 610041, P.R China.
Department of Respiratory Medicine, Nanchong Central Hospital, Nanchong 637000, P.R China.
Cancer Cell Int. 2013 Jun 1;13(1):53. doi: 10.1186/1475-2867-13-53.
The pro-apoptotic Bcl-2 protein BAD initiated apoptosis in human cells and has been identified as a prognostic marker in non-small cell lung cancer (NSCLC). In this study, we aimed to explore the functions of BAD in NSCLC.
Overexpression of BAD was performed by transfecting different NSCLC cell lines with wild-type BAD. Cell proliferation, cell cycle, apoptosis, and invasion were characterized in vitro. Tumorigenicity was analyzed in vivo. Western blot was performed to determine the effects of BAD overexpression on the Bcl-2 family proteins and apoptosis-related proteins.
Overexpression of BAD significantly inhibited cell proliferation in H1299, H292, and SPC-A1 but not in SK-MES-1 and H460 cell lines in vitro. BAD overexpression also reduced the tumorigenicity of H1299/SPC-A1 cell in vivo. However, no appreciable effects on cell cycle distribution and invasion were observed in all these cell lines. BAD overexpression also induced apoptosis in all cell types, in which process expression of mitochondrial cytochrom c (cyto-c) and caspase 3 were increased, whereas Bcl-xl, Bcl-2, Bax and caspase 8 expressions did not changed. These findings indicated that a mitochondrial pathway, in which process cyto-c was released from mitochondrial to activate caspase 3, was involved in BAD overexpression-mediated apoptosis.
Our data suggested that increased expression of BAD enhance apoptosis and has negative influence on cell proliferation and tumor growth in NSCLC. Bad is a new potential target for tumor interventions.
促凋亡 Bcl-2 蛋白 BAD 可诱导人细胞发生凋亡，并且已被鉴定为非小细胞肺癌（NSCLC）的预后标志物。在本研究中，我们旨在探索 BAD 在 NSCLC 中的功能。
通过转染野生型 BAD 到不同的 NSCLC 细胞系中实现 BAD 的过表达。在体外研究细胞增殖、细胞周期、凋亡和侵袭。在体内分析肿瘤生成能力。Western blot 用于确定 BAD 过表达对 Bcl-2 家族蛋白和凋亡相关蛋白的影响。
BAD 的过表达显著抑制了 H1299、H292 和 SPC-A1 细胞系中体外的细胞增殖，但对 SK-MES-1 和 H460 细胞系没有影响。BAD 过表达也降低了 H1299/SPC-A1 细胞在体内的致瘤性。然而，在所有这些细胞系中均未观察到对细胞周期分布和侵袭的明显影响。BAD 的过表达也诱导了所有细胞类型的凋亡，在此过程中线粒体细胞色素 c（cyto-c）和 caspase 3 的表达增加，而 Bcl-xl、Bcl-2、Bax 和 caspase 8 的表达没有改变。这些发现表明，BAD 过表达诱导的凋亡涉及线粒体途径，其中细胞色素 c 从线粒体释放并激活 caspase 3。
我们的数据表明，BAD 表达增加可增强凋亡，并对 NSCLC 中的细胞增殖和肿瘤生长产生负面影响。Bad 是肿瘤干预的一个新的潜在靶点。
