TRIFLAVIN, AN ARG-GLY-ASP-CONTAINING ANTIPLATELET PEPTIDE INHIBITS CELL-SUBSTRATUM ADHESION AND MELANOMA CELL-INDUCED LUNG COLONIZATION

Triflavin, an Arg-Gly-Asp (RGD) containing peptide purified from Trimeresurus flavoviridis snake venom, inhibits human platelet aggregation by blocking fibrinogen binding to fibrinogen receptors associated with glycoprotein IIb/IIIa complex. In this study, we show that triflavin (1-30-mu-g/mouse) inhibits B16-F10 melanoma cell-induced lung colonization in C57BL/6 mice in a dose-dependent manner. In vitro, triflavin dose-dependently inhibits adhesion of B16-F10 melanoma cells to extracellular matrices (ECMs; i.e., fibronectin, fibrinogen, vitronectin, and collagen type I). Triflavin is approximately 600-800 times more potent than GRGDS at inhibiting cell adhesion. In addition, triflavin dose-dependently inhibits B16-F10 cell-induced platelet aggregation. These results imply that the inhibitory effect of triflavin on the adhesion of tumor cells to ECMs (e.g., fibronectin, vitronectin and collagen type I) and/or tumor cell-induced platelet aggregation may be partially responsible for its antimetastatic activity in C57BL/6 mice.