Isolation of a novel peptide homing to tumor-derived neovasculature that suppresses tumor growth.

Novel peptides homing to angiogenic vessels were recently isolated from a phage-displayed random pentade-capeptide library, and peptides having WRP sequence showed tumor growth suppression. In this study, we observed that another novel sequence, PVVLFPLH, suppressed tumor growth in vivo. Through the study of tumor growth suppression by the 5-mer peptides derived from this sequence, we determined the epitope sequence to be LFPLH. LFPLH, but not the shuffled peptide FHLLP, suppressed the migration of vascular endothelial growth factor-stimulated human umbilical vein endothelial cells. Interestingly, growth suppression of LFPLH against the cells as well as tumor cells was not observed in vitro. Therefore LFPLH may function to induce tumor dormancy through inhibition of angiogenesis.