A novel disintegrin salmosin inhibits tumor angiogenesis

Salmosin is a snake venom-derived novel disintegrin that antagonizes platel et aggregation. In this study, we investigated its functional specificity i n tumor angiogenesis, Salmosin significantly inhibited bovine capillary end othelial cell proliferation induced by basic fibroblast growth factor but h ad no effect on normal growth of the cell. The basic fibroblast growth fact or-induced in vivo angiogenesis in the chorioallantoic membrane was disrupt ed by salmosin treatment without affecting normal embryonic angiogenesis. A dhesion of the bovine capillary endothelial cells to vitronectin was also i nhibited by the binding of salmosin to the alpha(v)beta(3) integrin. Both t he metastatic-tumor growth and the solid-tumor growth that developed in mic e were effectively suppressed by salmosin treatment. Several lines of exper imental evidence strongly suggest that the tumor-specific antiangiogenic ac tivity of salmosin disrupts tumor growth by blocking the alpha(v)beta(3) in tegrin that is expressed on the vascular endothelial cell surface.