AIM:To evaluate whether celecoxib, a selective cyclooxygenase 2 (COX-2) inhibitor, could reduce the severity of gastric precancerous lesions following Helicobacter pylori (H pylori ) eradication.METHODS: H pylori -eradicated patients with gastric precancerous lesions randomly received either celecoxib (n = 30) or placebo (n = 30) for up to 3 mo. COX-2 expression and activity was determined by immunostaining and prostaglandin E 2 (PGE 2 ) assay, cell proliferation by Ki-67 immunostaining, apoptosis by TUNEL staining and angiogenesis by microvascular density (MVD) assay using CD31 staining. RESULTS:COX-2 protein expression was significantly increased in gastric precancerous lesions (atrophy, intestinal metaplasia and dysplasia, respectively) compared with chronic gastritis, and was concomitant with an increase in cell proliferation and angiogenesis. A significant improvement in precancerous lesions was observed in patients who received celecoxib compared with those who received placebo (P < 0.001). Of these three changes, 84.6% of sites with dysplasia regressed in patients treated with celecoxib (P = 0.002) compared with 60% in the placebo group, suggesting that celecoxib was effective on the regression of dysplasia. COX-2 protein expression (P < 0.001) and COX-2 activity (P < 0.001) in the gastric tissues were consistently lower in celecoxib-treated patients compared with the placebo-treated subjects. Moreover, it was also shown that celecoxib suppressed cell proliferation (P < 0.01), induced cell apoptosis (P < 0.01) and inhibited angiogenesis with decreased MVD (P < 0.001). However, all of these effects were not seen in placebo-treated subjects. Furthermore, COX-2 inhibition resulted in the up-regulation of PPARg expression, a protective molecule with anti-neoplastic effects.CONCLUSION: H pylori eradication therapy followed by celecoxib treatment improves gastric precancerous lesions by inhibiting COX-2 activity, inducing apoptosis, and suppressing cell proliferation and angiogenesis.

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