OBJECTIVETo study the effect of angiogenesis inhibitor Rg3 on the growth and metastasis of gastric cancer in SCID mice.

METHODSMetastatic model simulating human gastric cancer was established by orthotopic implantation of histologically intact human tumor tissue into the gastric wall of SCID mice. Rg3 was administered by gastric perfusion at doses of 0, 2.5, 5.0, 10.0 mg/kg every day for 6 weeks 1 week after tumor implantation. One week after last administration, the mice were killed and their tumor weight was measured and the presence of metastasis recorded. Intratumoral microvessel density was examined by immunohistochemical staining with anti-CD31 monoclonal antibody.

RESULTSCompared to the untreated controls, the growth of the orthotopically implanted tumor was significantly reduced in weight in mice treated with Rg3 with an inhibition rate of 52.3%, 63.3% and 71.6% at doses of 2.5, 5.0, 10.0 mg/kg, respectively. Tumor metastasis to the liver and peritoneum was also significantly inhibited in a dose-dependent manner. Decreased intratumoral microvessel density was noted in the treated mice.

CONCLUSIONAngiogenesis inhibitor Rg3 has strong inhibitory effect on tumor growth and metastasis of human gastric cancer in SCID mice.