Wang Fen, Qu Nanfang, Peng Jin, Yue Chun, Yuan Lingzhi, Yuan Yi
Department of Gastroenterology, The Third Xiangya Hospital, Central South University, Changsha, Hunan 410013, P.R. China.
Department of Gastroenterology, The Affiliated Hospital of Guilin Medical College, Guilin, Guangxi 541001, P.R. China.
Mol Med Rep. 2017 Aug;16(2):1262-1268. doi: 10.3892/mmr.2017.6757. Epub 2017 Jun 12.
Cytotoxin-associated gene A (CagA) is one of the most important virulence factors of Helicobacter pylori, and serves a role in H. pylori‑mediated tumorigenesis in gastric cancer. However, the underlying molecular mechanism remains to be elucidated. The present study aimed to investigate the effects of CagA on the proliferation and apoptosis of GES‑1 cells, and the underlying mechanism. A CagA eukaryotic expression plasmid was constructed and transfected into GES‑1 cells. The mRNA and protein levels of CagA, tumor necrosis factor receptor‑associated factor 1 (TRAF1) and tumor necrosis factor receptor superfamily member 9 (4‑1BB) were determined using the reverse transcription‑quantitative polymerase chain reaction and western blot analysis, respectively. Western blot and ELISA analysis was used to detect the release of interleukin (IL)‑8. An MTT assay and flow cytometric analysis was used to assess cell viability and apoptosis, respectively. Ectopic expression of CagA markedly increased TRAF1 and 4‑1BB mRNA and protein levels in GES‑1 cells. CagA increased the expression and release of IL‑8 in GES‑1 cells. The expression of CagA significantly promoted the proliferation (P<0.05) and inhibited the apoptosis (P<0.05) of GES‑1 cells. In conclusion, CagA upregulated TRAF1/4‑1BB, thereby promoting the proliferation and inhibiting the apoptosis of GES-1 cells.
细胞毒素相关基因A（CagA）是幽门螺杆菌最重要的毒力因子之一，在幽门螺杆菌介导的胃癌肿瘤发生过程中发挥作用。然而，其潜在的分子机制仍有待阐明。本研究旨在探讨CagA对GES-1细胞增殖和凋亡的影响及其潜在机制。构建了CagA真核表达质粒并将其转染至GES-1细胞中。分别采用逆转录-定量聚合酶链反应和蛋白质免疫印迹分析测定CagA、肿瘤坏死因子受体相关因子1（TRAF1）和肿瘤坏死因子受体超家族成员9（4-1BB）的mRNA和蛋白质水平。采用蛋白质免疫印迹和酶联免疫吸附测定分析检测白细胞介素（IL）-8的释放。分别采用MTT法和流式细胞术分析评估细胞活力和凋亡情况。CagA的异位表达显著增加了GES-1细胞中TRAF1和4-1BB的mRNA及蛋白质水平。CagA增加了GES-1细胞中IL-8的表达和释放。CagA的表达显著促进了GES-1细胞的增殖（P<0.05）并抑制了其凋亡（P<0.05）。总之，CagA上调TRAF1/4-1BB，从而促进GES-1细胞的增殖并抑制其凋亡。
