Effect of angiogenesis inhibitor TNP-470 on the progression of human gastric cancer xenotransplanted into nude mice

The effect of an angiogenesis inhibitor, TNP-470, on primary tumor growth, liver metastasis and peritoneal dissemination of gastric cancer was investigated by means of an orthotopic xenotransplanted model of 2 human gastric cancers, MT-2 and MT-5. TNP-470 showed a significant inhibitory effect on the growth of primary tumors after orthotopic transplantation of both xenografts when given at a dose of 30 mg/kg on alternate days from day 7 after transplantation (early treatment). However, growth of the MT-2 primary tumor was not inhibited by administration from day 14 after transplantation (late treatment). Liver metastasis was prevented significantly by early treatment of TNP-470. In particular, early treatment of MT-2 completely inhibited the development of macroscopic foci in the liver and was significantly more effective than late treatment. Peritoneal dissemination also was inhibited. Thus, TNP-470 was revealed to have strong inhibitory activity not only on primary tumors and liver metastases but also against peritoneal dissemination. These results suggest that this agent may provide a new approach to the treatment of gastric cancer.