Department of Internal Medicine, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea. ; Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Seoul, Korea.
Gut Liver. 2013 Sep;7(5):552-9. doi: 10.5009/gnl.2013.7.5.552. Epub 2013 Aug 14.
BACKGROUND/AIMS: Helicobacter pylori infection induces cyclooxygenase-2 (COX-2) and epidermal growth factor receptor (EGFR) overexpression, and these factors may engage in cross-talk. The aim of the present study was to evaluate the effect of H. pylori on EGFR signaling pathways and to determine whether celecoxib has an inhibitory effect on this pathway.
The AGS cell line was cocultured with H. pylori G27 and the isogenic cagE- mutant. The expression of COX-2, EGFR, heparin binding-epidermal growth factor (HB-EGF), and transforming growth factor-β (TGF-β) was measured by real time-polymerase chain reaction (RT-PCR). Next, Western blot analyses of COX-2, EGFR, total Akt, phosphorylated Akt (pAkt), and phosphorylated glycogen synthase kinase-3β (pGSK3β) were performed after incubating H. pylori-treated AGS cells for 24 hours with various concentrations of celecoxib (0, 10, 20, and 30 µmol/L).
H. pylori infection upregulated the mRNA levels of COX-2, EGFR, HB-EGF, and TGF-β, as detected by RT-PCR. However, AGS cells treated with cagE- mutants, which have a defective type IV secretion system, did not exhibit EGFR upregulation. Celecoxib had inhibitory effects on the H. pylori-induced overexpression of COX-2 (p=0.015), EGFR (p=0.025), pAkt (p=0.025), and pGSK3β (p=0.029) by Western blot analysis.
H. pylori with an intact type IV secretion system activated the COX-2 and EGFR-Akt pathways in the AGS cell line. As celecoxib exhibited inhibitory effects on the EGFR signaling pathway, the cross-talk of COX-2 and EGFR likely mediates H. pylori-induced gastric cancer.
背景/目的：幽门螺杆菌感染诱导环氧化酶-2（COX-2）和表皮生长因子受体（EGFR）过表达，这些因素可能相互作用。本研究旨在评估幽门螺杆菌对 EGFR 信号通路的影响，并确定塞来昔布是否对该通路具有抑制作用。
AGS 细胞系与幽门螺杆菌 G27 和同源性 cagE-突变体共培养。通过实时聚合酶链反应（RT-PCR）测量 COX-2、EGFR、肝素结合表皮生长因子（HB-EGF）和转化生长因子-β（TGF-β）的表达。然后，用不同浓度的塞来昔布（0、10、20 和 30 μmol/L）孵育幽门螺杆菌处理的 AGS 细胞 24 小时后，通过 Western blot 分析测定 COX-2、EGFR、总 Akt、磷酸化 Akt（pAkt）和磷酸化糖原合成酶激酶-3β（pGSK3β）的表达。
RT-PCR 检测到幽门螺杆菌感染上调了 COX-2、EGFR、HB-EGF 和 TGF-β 的 mRNA 水平。然而，AGS 细胞用缺乏 IV 型分泌系统的 cagE-突变体处理后并未显示 EGFR 上调。塞来昔布对幽门螺杆菌诱导的 COX-2（p=0.015）、EGFR（p=0.025）、pAkt（p=0.025）和 pGSK3β（p=0.029）过表达具有抑制作用。
具有完整 IV 型分泌系统的幽门螺杆菌在 AGS 细胞系中激活了 COX-2 和 EGFR-Akt 通路。由于塞来昔布对 EGFR 信号通路具有抑制作用，COX-2 和 EGFR 的相互作用可能介导了幽门螺杆菌诱导的胃癌。
