Helicobacter pylori infection induces cyclooxygenase-2 expression in gastric mucosa / 中华消化内镜杂志

ABSTRACT

Objective Adenocarcinoma of the stomach has been established as a consequence of gastric infection with Helicobacter pylori(H.pylori).The specific role of H.pylori in the pathogenesis is unknown yet.Recent studies indicate that expression of mitogen inducible cyclooxygenase-2(COX-2) occurs in gastrointestinal tumors.The purpose of the present study was to investigate expression of COX-2 protein in the human stomach with or without H.pylori infection.Methods Twenty-seven subjects who were asymptomatic referred to the hospital for healthy examination including endoscopic screening.Biopsy specimens were obtained from the subjects without any macroscopic lesions,such as peptic ulcer or gastric malignancies.H.pylori infection was determined by rapid urease test(CLO test),bacterial culture and histology(Giemsa staining).Expression of COX-2 was evaluated by immunohistochemistry using the avidin-biotin-peroxide complex(ABC) method The association between COX-2 expression and H.Pylori infection was assessed by Fisher's exact test.A P value less than 0.05 was considered to be statistically significant.Results specific immunostaining for COX-2 was observed in antral mucosa of 18 subjects infected with H.pylori COX-2 was expressed in gastric mucosal epithelia,mainly in the foveolar epithelial cells.Furthermore,COX-2 was also observed in the neck cells of the gastric glands and inflammatory mononuclear cells beneath the mucosal epithelia.Expression of COX-2 was never found in the gastric mucosa of H.pylori-negative subjects.A positive association of H.pylori infection with COX-2 expression was statistically significant(P