BACKGROUND cag pathogenicity island (PAI) is reported to be a major virulence factor of Helicobacter pylori. AIM To characterise cagA and the cag PAI in Japanese H pylori strains. METHODS H pylori isolates from Japanese patients were evaluated for CagA by immunoblot, for cagA transcription by northern blot, and for cagA and 13 other cag PAI genes by Southern blot. cagA negative strains from...

Risk factors for gastric cancer are receiving renewed attention in light of the recent positive association of Helicobacter pylori infection with gastric cancer. The effect of H.pylori on the balance between oxidants and antioxidants in the stomach is not well known. In this study, we investigated if exposure of gastric cells to H. pylori increases oxidant-associated gastric epithelial cell inj...

CagA seropositivity is an important risk factor for gastric adenocarcinoma and duodenal ulcer. However, CagA seropositivity is also found in Helicobacter pylori-seronegative subjects. Is CagA seropositivity in these subjects a sign of a past H. pylori infection, or does it represent a false-positive reaction? This study investigates the intensity of the CagA immune reaction and the variation in...

The gastric pathogen Helicobacter pylori uses a type IV secretion system to inject the bacterial CagA protein into gastric epithelial cells. Within the host cell, CagA becomes phosphorylated on tyrosine residues and initiates cytoskeletal rearrangements. We demonstrate here that Src-like protein-tyrosine kinases mediate CagA phosphorylation in vitro and in vivo. First, the Src-specific tyrosine...

INTRODUCTION Helicobacter pylori strains expressing cytotoxic CagA protein are more commonly associated with peptic ulceration, atrophic gastritis and gastric adenocarcinoma than those lacking CagA. Determination of anti-CagA antibodies, therefore, acquires a relevant clinical significance in the serological detection of H. pylori infection and disease risk prediction. However, the CagA-serolog...

BACKGROUND Despite a possible role of Helicobacter pylori in gastric carcinoma (GC), its pathogenesis is not clear. There is scanty data on apoptosis in GC in relation to H. pylori and CagA antibody. Therefore, we studied gastric epithelial apoptosis in GC and non-ulcer dyspepsia (NUD) with or without H. pylori infection, and the degree of apoptosis in relation to CagA antibody status. METHOD...

Helicobacter pylori is a causative agent of gastritis and peptic ulcer. cagA(+) H. pylori strains are more virulent than cagA(-) strains and are associated with gastric carcinoma. The cagA gene product, CagA, is injected by the bacterium into gastric epithelial cells and subsequently undergoes tyrosine phosphorylation. The phosphorylated CagA specifically binds SHP-2 phosphatase, activates the ...

Gastric cancer development is strongly correlated with infection by Helicobacter pylori possessing the effector protein CagA. Using a transgenic Drosophila melanogaster model, we show that CagA expression in the simple model epithelium of the larval wing imaginal disc causes dramatic tissue perturbations and apoptosis when CagA-expressing and non-expressing cells are juxtaposed. This cell death...

Infection with Helicobacter pylori is a major risk factor for the development of gastric cancer, and infection with strains carrying the virulence factor CagA significantly increases this risk. To investigate the mechanisms by which CagA promotes carcinogenesis, we generated transgenic zebrafish expressing CagA ubiquitously or in the anterior intestine. Transgenic zebrafish expressing either th...