Gut Liver. 2013;7(5):552-9.

The Effect of Helicobacter pylori on Epidermal Growth Factor Receptor-Induced Signal Transduction and the Preventive Effect of Celecoxib in Gastric Cancer Cells.

, , , , , , , ,

제1저자 김재영 · 교신저자 김나영

PMID 24073313 PMC3782670 DOI 10.5009/gnl.2013.7.5.552 IF 4.1 소화기내과

소속 (1)

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.

Abstract

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.

METHODS 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).

RESULTS 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.

CONCLUSIONS 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.

Keywords

CelecoxibCyclooxygenase 2Gastric carcinomaHelicobacter pyloriReceptor, epidermal growth factor

Figures

**Fig. 1** Real-time polymerase chain reaction results for cyclooxygenase-2 (COX-2), epidermal growth factor receptor (EGFR), heparin binding-epidermal growth factor (HB-EGF), and transforming growth factor-β (TGF-β) in the AGS cell line after treatment with *Helicobacter pylori*. The incubation of AGS cells treated with wild type G27 or the *cagE*- isogenic mutant resulted in different mRNA expression. (A) COX-2, (B) EGFR, (C) HB-EGF, and (D) TGF-β. Overexpression of COX-2, EGFR, HB-EGF, and TGF-β was observed in AGS cells treated with the wild type *H. pylori* strain G27. There was no significant difference between the levels of mRNA in the cells treated with the *cagE*- isogenic mutant and in the AGS control. Compared with AGS cells treated with wild type G27, the expression of HB-EGF (p=0.001) and EGFR (p=0.010) was significantly lower in cells treated with the *cagE*- isogenic mutant. HP, *Helicobacter pylori*. ^*p<0.05 compared with AGS cells; ^†p<0.05 compared with wild type G27.

**Fig. 2** Western blotting for (A) cyclooxygenase-2 (COX-2), (B) epidermal growth factor receptor (EGFR), (C) total Akt (tAkt), (D) phosphorylated Akt (pAKt), and (E) phosphorylated glycogen synthase kinase-3β (pGSK3β) in *Helicobacter pylori*-infected AGS cells. The incubation of AGS cells infected by the *H. pylori* G69a strain and an AGS cell control with various concentrations (0, 10, 20, and 30 µmol/L) of celecoxib for 24 hours resulted in different protein expression. (A) AGS cells treated with the *H. pylori* G69a strain exhibited COX-2 overexpression (p=0.001). The 10, 20, and 30 µmol/L concentrations of celecoxib had inhibitory effects on the protein expression of COX-2 in the AGS control (p=0.026. p=0.001, and p=0.017, respectively). The 20 µmol/L concentration of celecoxib had inhibitory effects on the protein expression of COX-2 in *H. pylori*-treated AGS cells (p=0.015). (B) AGS cells treated with the *H. pylori* G69a strain exhibited significant EGFR overexpression (p<0.001). The 20 and 30 µmol/L concentrations of celecoxib had inhibitory effects on the protein expression of EGFR in *H. pylori*-treated AGS cells (p=0.025 and p=0.004, respectively). (C, D) AGS cells treated with the *H. pylori* G69a strain exhibited overexpression of pAkt (p<0.001) but not tAkt. The 30 µmol/L concentration of celecoxib had inhibitory effects on the expression of tAkt in the AGS control (p=0.020). There was a significant increase in pAkt expression after *H. pylori* infection (p=0.001). The 10, 20, and 30 µmol/L concentrations of celecoxib inhibited the overexpression of pAkt after 24 hours of incubation with the AGS control (p=0.026, p=0.001, and p=0.017, respectively). The 20 µmol/L concentration of celecoxib inhibited overexpression of pAkt after 24 hours of incubation with AGS cells treated with the G69a strain (p=0.015). (E) AGS cells treated with the *H. pylori* G69a strain showed significant overexpression of phosphorylated glycogen synthase kinase-3β (pGSK3β) (p=0029). The 20 µmol/L concentration of celecoxib had a significant inhibitory effect on the expression of pGSK3β in AGS cells treated with the G69a strain (p=0.029). ^*p<0.05 compared with the AGS control; ^†p<0.05 compared with *H. pylori*-infected cells without celecoxib treatment.

그림 출처: PubMed Central 공개 논문 (PMC3782670)

Conflict of interest statement

No potential conflict of interest relevant to this article was reported.

그 밖의 정보