BAG2基因影响A549细胞增殖的机制研究及其临床意义

目的:研究Bcl-2相关抗凋亡基因2(Bcl-2-associated athanogene,BAG2)对人肺腺癌A549细胞增殖能力的影响及作用机制,并探讨其临床意义。方法:以Western blot法分析BAG2在A549细胞与正常上皮细胞系HBE中的蛋白表达水平;在体外以RNA干扰(RNAi)技术敲低A549细胞中BAG2基因的表达,并采用CFSE染色结合流式细胞术、WST-1法和Western blot法对A549细胞增殖和细胞周期相关蛋白进行评价。此外,我们利用q PCR检测BAG2在肺癌组织c DNA芯片中的表达情况,同时分析了GEO数据库中BAG2表达与肺癌患者预后之间的关系。结果:与HBE细胞比较,A549细胞中BAG2的表达显著升高(P0.05);干扰BAG2基因后,A549细胞在48 h和72 h时点时增殖均被抑制;在48 h时点,干扰BAG2可导致细胞周期蛋白cyclin B1与cyclin E1表达显著下调(P0.05)。在人肺癌组织中,BAG2基因表达显著高于癌旁组织,并与肺癌患者生存预后呈显著负相关(P0.01)。结论:BAG2基因可能通过上调细胞周期蛋白cyclin B1与cyclin E1影响A549细胞的增殖,其表达量与肺癌患者预后呈显著负相关。

Role of BAG2 gene in A549 cell proliferation and its clinical implications

AIM: To investigate the role of Bcl-2-associated athanogene 2 (BAG2) in the proliferation of human lung adenocarcinoma A549 cells and its clinical implications. METHODS: The abundance of BAG2 protein in A549 and lung bronchial epithelium (HBE) cells were measured by Western blot. After down-regulation of BAG2 by transfection of siRNA in A549 cells, the expression of cell proliferation and cell cycle related proteins were detected by CFSE assay, WST-1 assay and Western blot, respectively. Moreover, the expression of BAG2 in cDNA array which contained 10 pairs of lung cancer and adjacent tissue was verified. Meanwhile, BAG2 expression in GEO database, which included the human lung cancer and adjacent tissue microarray data was analyzed. The prognosis power of BAG2 was evaluated by the Kaplan-Meier survival curve analysis. RESULTS: BAG2 had remarkably higher expression level in A549 cells than that in HBE cells. Knockdown of BAG2 resulted in significantly inhibition of proliferation in A549 cells, accompany with the significantly down-regulation of cyclin B1 and cyclin E1. BAG2 was over-expressed in the lung cancer tissues, as compared with the adjacent normal tissues. Kaplan-Meier plotter and cDNA microarray results showed that patients with higher BAG2 expression were significantly associated with poorer survival. CONCLUSION: The BAG2 gene tends to regulate A549 cells proliferation via cyclin B1 and cyclin E1. BAG2 has significantly prognostic power on the survival of lung cancer patients.