Role of Helicobacter pylori infection in pathogenesis of gastric adenocarcinoma.

To study the effect of Helicobacter Pylori (Hp) on the process of gastric carcinogenesis, 35 cases of chronic gastritis, 20 cases of gastric adenocarcinoma were studied by use of transmission electron microscopy, immunohistochemical and molecular biological technique. The results showed that 24 of 35 cases of chronic gastritis were positive for Hp, 11/20 cases of gastric adenocarcinoma were Hp positive. PCNA positive cell labeling index (LI) in Hp-associated chronic gastritis (LI = 20.6 +/- 4.7) was higher than that in Hp negative chronic gastritis (LI = 11.3 +/- 5.2) (P < 0.05). HSP70 expression of gastric adenocarcinoma tissues in Hp-infected patients were lower than that of non-Hp-infected gastric cancer. p53 gene mutation was found in gastric adenocarcinoma with positive Hp. It was suggested that Hp may enhance gastric cell proliferation, decrease the expression of HSP70 which induces p53 mutation.