Inhibitory effects of the antiangiogenic agent TNP-470 on establishment and growth of hematogenous metastasis of human pancreatic carcinoma in SCID beige mice in vivo

Effects on the liver of the antiangiogenesis agent O-(chloroacetyl-carbamoyl) fumagillol (TNP-470) on hematogenous metastasis of a human pancreatic carcinoma cell line were examined. One million PCI-43 cells, a human pancreas carcinoma cell line, were injected into the spleen of SCID beige mice, then TNP-470 at 30 mg/kg was administered subcutaneously every other day. The mice were killed 6 or 10 weeks thereafter and metastatic nodules in the liver were counted and measured microscopically. Metastases were inhibited and an approximately 10% loss of weight was evident in the TNP-470-administered mice. There was no suppression in maximal size of metastatic colonies in mice given the agent for 6 weeks, while inhibition was apparent in mice given the drug for 10 weeks. Suppression of proliferation and an increase in apoptosis were evident in metastatic nodules in the TNP-470-administered groups, following stainings for proliferative cell nuclear antigen and terminal deoxytransferase-mediated dUTP-biotin nick end-labeling, respectively. TNP-470 inhibited the proliferation of human umbilical vein endothelial cells but not PCI-43 in vitro. TNP-470 did not suppress production of vascular endothelial growth factor by PCI-43 cells. Neovascularization in vivo induced by PCI-43 cells was suppressed in the TNP-470-administered mice, using a diffusion chamber placed in subcutaneous tissues of SCID beige mice. These observations suggest that inhibition of angiogenesis is effective in suppressing establishment and subsequent growth of hematogenous micrometastases of pancreatic adenocarcinoma to the liver.