Published online Oct 7, 2005. doi: 10.3748/wjg.v11.i37.5899
Revised: February 13, 2005
Accepted: February 18, 2005
Published online: October 7, 2005
AIM: To investigate the effect of Helicobacter pylori (H pylori) infection on Bax protein expression, and explore the role of H pylori in gastric carcinogenesis.
METHODS: H pylori was assessed by rapid urease test and Warthin-Starry method, and expression of Bax protein was examined immunohistochemically in 72 patients with pre-malignant lesions.
RESULTS: Bax protein was differently expressed in intestinal metaplasia and gastric dysplasia, and showed 63.99% positivity. The positivity of Bax protein expression in H pylori-positive gastric precancerous lesions (72.3%) was significantly higher than that in H pylori-negative gastric precancerous lesions (48.0%, c2 = 4.191, P < 0.05). H pylori infection was well correlated with the expression of Bax protein in gastric precancerous lesions (r = 0.978, P < 0.01). After eradication of H pylori, the positivity of Bax protein expression significantly decreased in H pylori-positive gastric precancerous lesions (c2 = 5.506, P < 0.05). In the persisting H pylori-infected patients, the positivity of Bax protein expression was not changed.
CONCLUSION: H pylori infection may be involved in the upregulation of Bax gene, which might be one of the mechanisms of H pylori infection-induced gastric epithelial cell apoptosis. H pylori might act as a tumor promoter in the genesis of gastric carcinoma and eradication of H pylori could inhibit gastric carcinogenesis.