Anti-angiogenic treatment for peritoneal dissemination of pancreas adenocarcinoma: a study using TNP-470.

We established peritoneal dissemination-prone subcultures (PCI-43p3) using nude mice by a repetitive in vivo selection of intraperitoneally inoculated PCI-43, a pancreas adenocarcinoma cell line. The subcultures showed upregulated expression of matrix metalloproteinase (MMP)-9, but not MMP-2 in culture supernatants. They also produced increased amounts of vascular endothelial growth factor (VEGF), which was not associated with alterations in isoforms of VEGF mRNA. PCI-43p3 cells attached to cultured mesothelial cell monolayers more readily than did the parent PCI-43 cells. The angiogenesis inhibiting agent, TNP-470, at 30 mg / kg was administered to the model mice, resulting in a prominent suppression of the establishment of peritoneal nodules. The suppression was dependent on the duration of TNP-470 treatment. TNP-470 treatment significantly suppressed proliferation of tumor cells in disseminated nodules, assessed in terms of immunostaining for proliferating cell nuclear antigen (PCNA). TNP-470 did not affect the in vitro attachment between PCI-43p3 and mesothelial cells. The combined data show that anti-angiogenic treatment profoundly suppresses the in vivo process of peritoneal dissemination.