Men Wanfu, Li Wenya, Zhao Jungang, Li Yu
Cell Physiol Biochem. 2018;47(5):2097-2108. doi: 10.1159/000491478. Epub 2018 Jul 5.
BACKGROUND/AIMS: TNF-α receptor-associated factor (TRAF)-interacting protein with a forkhead-associated (FHA) domain (TIFA) may mediate the impact of TRAF on the development of lung cancer. The current study was conducted to investigate the expression of TIFA in lung adenocarcinoma and its potential role in the regulation of cancer cell proliferation and migration, and its influence on patient survival.
Specimens of lung adenocarcinoma tissues and their adjacent normal lung tissues were obtained from 116 patients who underwent surgical resection of lung cancer. The expression of TIFA in the lung tissues was examined by immunohistochemistry, immunoblotting, and real-time RT-PCR in four different lung cancer cell lines and one normal bronchial epithelial cell line (BEAS-2B). TIFA was silenced by RNAi technique, and cell proliferation was then assessed by the CCK8 method. Furthermore, cell migration was determined by wound-healing trans-well and wound-healing migration assays. Additionally, cell-cycle arrest and apoptosis were assessed by flow cytometry analysis.
TIFA was positively detected in 63 (54.3%) out of 116 lung adenocarcinoma specimens, which was significantly higher than the respective rate established in normal tissues adjacent to the tumor (30.1%, p < 0.05). The overall survival rate was significantly lower in the patients with positive TIFA expression than that in the patients with negative TIFA expression (p < 0.05). TIFA was also highly expressed in the lung cancer cell lines (H1299, H1975, and HCC827) tested. It is noteworthy that siRNA suppressed the expression of TIFA, which contributed to the attenuation of cell proliferation and migration, but promoted cell-cycle arrest and apoptosis. Furthermore, the silencing of TIFA caused upregulation of p53, p21, and cleaved-caspase-3, but downregulation of Bcl-2, cyclin D1, and CDK4, as well as phosphorylation of IKKß, IκB, and p65.
TIFA may serve as a biomarker in the prediction of lung adenocarcinoma. Furthermore, TIFA may modulate lung cancer cell survival and proliferation through regulating the synthesis of apoptosis-associated proteins.
背景/目的：含叉头相关（FHA）结构域的肿瘤坏死因子-α受体相关因子（TRAF）相互作用蛋白（TIFA）可能介导TRAF对肺癌发生发展的影响。本研究旨在探讨TIFA在肺腺癌中的表达及其在调控癌细胞增殖和迁移中的潜在作用，以及对患者生存的影响。
从116例行肺癌手术切除的患者中获取肺腺癌组织及其癌旁正常肺组织标本。采用免疫组织化学、免疫印迹和实时RT-PCR检测4种不同肺癌细胞系和1种正常支气管上皮细胞系（BEAS-2B）中TIFA在肺组织中的表达。通过RNAi技术沉默TIFA，然后用CCK8法评估细胞增殖。此外，通过伤口愈合Transwell和伤口愈合迁移试验测定细胞迁移。另外，通过流式细胞术分析评估细胞周期阻滞和凋亡。
116例肺腺癌标本中有63例（54.3%）TIFA呈阳性检测，显著高于肿瘤旁正常组织的相应比例（30.1%，p<0.05）。TIFA表达阳性患者的总生存率显著低于TIFA表达阴性患者（p<0.05）。在所检测的肺癌细胞系（H1299、H1975和HCC827）中TIFA也高表达。值得注意的是，siRNA抑制了TIFA的表达，这导致细胞增殖和迁移减弱，但促进了细胞周期阻滞和凋亡。此外，TIFA的沉默导致p53、p21和裂解的caspase-3上调，但Bcl-2、细胞周期蛋白D1和CDK4下调，以及IKKβ、IκB和p65的磷酸化。
TIFA可能作为预测肺腺癌的生物标志物。此外，TIFA可能通过调节凋亡相关蛋白的合成来调节肺癌细胞的存活和增殖。
