Abstract: BACKGROUND AND AIM: To investigate the effects and mechanisms of sulindac on mice xenograft, angiogenesis and biologic behaviour of gastric cancer. MATERIALS AND METHODS: Twenty athymic xeograft models with human gastric cancer cell BGC_823 were established and randomly divided into four groups,sulindac treated group (12 mg/kg),sulindac preventive group(8 mg/kg),vitamin C group(Vit C 20 mg/kg) and control group. Immunohistochemistry was used to detect the expression of COX_2,VEGF and MVD in xenografts cells.TUNEL technique was applied to examine apoptosis. RESULTS: The growth of xenografts were markedly depressed by two weeks of sulindac treatment.The xenografts volume of sulindac_treated group and sulindac_preventive group were (57.2±3.2) mm3 and (77.8±6.7) mm3,respectively significantly smaller than those of vitamin C group and control group[(120.6±12.17) mm3 and (87.7±29.0) mm3 respectively,P<0.05]. The xenograft volume maintained the difference until the experiment was finished. In vitamin C and control groups, the xenograft, apoptosis indexes(3.5 and 3.1,respectively ) were lower than those in sulindac_treated and sulindac_preventive groups(11.6 and 10.4, respectively,P<0.05).Compared with vitamin C and control groups(19.6 and 20.7), the microvessel densities were remarkedly reduced in sulindac_treated and sulindac preventive groups(5.4 and 9.0, respectively, P<0.01). Compared with vitamin C and control groups,the expression of COX_2 and VEGF decreased markedly in sulindac_treated and sulindac_preventive groups (P<0.05). CONCLUSION: Sulindac had obvious anti_cancer effects in vivo against gastric cancer. The mechanism of its'anti_cancer effects may include suppressing proliferation, inducing apoptosis, and reducing angiogenesis.

Key words: gastric tumor, nude mice, sulindac, cyclooxygenase_2, angiogenesis