VASCULAR ENDOTHELIAL GROWTH-FACTOR INDUCES THE DISORGANIZATION OF ACTIN STRESS FIBERS ACCOMPANIED BY PROTEIN-TYROSINE PHOSPHORYLATION AND MORPHOLOGICAL CHANGE IN BALB/C3T3 CELLS

The effects of vascular endothelial growth factor (VEGF) on cytoskeletal actin networks, cell morphology and tyrosine phosphorylation of cellular proteins were studied in Balb/c3T3 A31-1-1 cells. VEGF induced the disorganization of actin stress fibers accompanied by drastic morphological rounding. A binding assay of [I-125]VEGF demonstrated high and low affinity receptors for VEGF in the cells. Moreover, VEGF induced tyrosine phosphorylation of at least five cellular proteins in a dose and a time dependent manner. A tyrosine kinase inhibitor, genistein, inhibited the VEGF-induced morphological rounding. These results indicate that VEGF exerts the alteration of cytoskeletal organization resulting in morphological changes through inducing receptor-mediated tyrosine phosphorylation of cellular proteins. (C) 1994 Academic Press, Inc.