INHIBITION OF ANGIOGENESIS BY STAUROSPORINE, A POTENT PROTEIN-KINASE INHIBITOR

The effect of staurosporine, a potent inhibitor of protein kinases, on embryonic angiogenesis was studied in an in vivo assay system involving chorioallantoic membranes of growing chick embryo. Staurosporine inhibited embryonic angiogenesis in a dose-related manner, the ID50 value being 71 pmol/egg. Staurosporine dose-dependently suppressed the proliferation of vascular endothelial cells, an important event involved in the angiogenesis process. The IC50 value was 0.88 nM. In contrast, staurosporine did not affect the migration of vascular endothelial cells. These results suggest that staurosporine affected embryonic angiogenesis probably by inhibiting endothelial cell proliferation. In addition, these results might support the notion that certain protein kinase(s) could be implicated in induction of angiogenesis and also that staurosporine would be a useful compound for studying a mode of action of angiogenesis occurring in various diseases, including tumor development.