Expression of COX‐1, COX‐2 and inducible nitric oxide synthase in superficial gastritis, mucosal dysplasia and gastric carcinoma

OBJECTIVE: To investigate the significance of the expression of cyclooxygenase-1 (COX-1), cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) in superficial gastritis, gastric mucosal dysplasia and gastric carcinoma, and to study the relationship between COX-2, iNOS, gastric carcinoma and Helicobacter pylori infection. METHODS: Polyclonal antibodies to COX-1, COX-2 and iNOS were used detect their expression and the status of H. pylori infection in 92 specimens of paraffin-embedded gastric tissue. Of the 92 patients, 33 had superficial gastritis, 30 had gastric mucosal dysplasia and 29 had gastric cancer. Helicobacter pylori was detected by toluidine blue staining. RESULTS: Expression of COX-2 and iNOS in gastric cancer (65.5%, 62.1%) was significantly higher than that in gastritis (18.2%, 18.2%; P < 0.01). Expression of COX-2 and iNOS in gastritis with H. pylori infection was higher than that in gastric mucosal dysplasia with H. pylori infection. The expression of COX-2 and iNOS occurred concomitantly in gastritis, dysplasia and gastric cancer. CONCLUSION: Inflammation and H. pylori infection may be able to stimulate the expression of COX-2 and iNOS, which might be involved in gastric carcinogenesis.