title: Staurosporine promotes endothelial cell assembly and FAK phosphorylation during in vitro angiogenesis.
abstract: In the present study, we report that staurosporine, a known PKC inhibitor, enhanced in vitro angiogenesis. Endothelial cells plated in a three-dimensional matrix formed cords and enclosed structures within 4-6 hours. The cells in cord structures became elongated during the subsequent incubation. Tube formation was confirmed by confocal microscopy. Addition of VEGF enhanced the early responses of endothelial cells, leading to enhanced formation of cords. Staurosporine unexpectedly also enhanced the early endothelial responses, leading to faster alignment of cells and assembly into tube-like structures. At concentrations inhibitory to endothelial cell PKC activity, staurosporine produced 91% and 203% increases in the number of cords and the enclosed structures, respectively, as compared to the controls. Other selective inhibitors of PKC did not stimulate in vitro angiogenesis in the absence or presence of VEGF. Further investigation showed that inhibition of PI-3 kinase and Raf-1 significantly reduced the effects of staurosporine. Staurosporine-induced in vitro angiogenesis required integrins alpha2 and alphavbeta3 and was associated with significantly enhanced FAK phosphorylation. These data indicate that staurosporine enhances in vitro angiogenesis by a means unrelated to its PKC inhibition. The data suggest that enhancement of in vitro angiogenesis by staurosporine involves integrin-mediated signaling, including the stimulation of FAK phosphorylation.
authors.affiliation: Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana 46285, USA.
authors.forename: Sima T
authors.initials: ST
authors.lastname: Tarzami
authors.forename: Susie Shao-Hsu
authors.initials: SS
authors.lastname: Hsieh
authors.forename: Michail A
authors.initials: MA
authors.lastname: Esterman
authors.forename: Jai Pal
authors.initials: JP
authors.lastname: Singh
mesh_terms: D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D042783:Endothelial Cells / Q000187:drug effects* / Q000378:metabolism; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D051418:Focal Adhesion Kinase 2; D006801:Humans; D039421:Integrin alpha2 / Q000502:physiology; D039302:Integrin alphaVbeta3 / Q000502:physiology; D018613:Microscopy, Confocal; D018919:Neovascularization, Physiologic / Q000187:drug effects*; D019869:Phosphatidylinositol 3-Kinases / Q000502:physiology; D000081082:Phosphoinositide-3 Kinase Inhibitors; D010766:Phosphorylation; D011493:Protein Kinase C / Q000037:antagonists & inhibitors*; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D019908:Proto-Oncogene Proteins c-raf / Q000037:antagonists & inhibitors / Q000502:physiology; D019311:Staurosporine / Q000494:pharmacology*; D042461:Vascular Endothelial Growth Factor A / Q000494:pharmacology
chemical_list: D051418:Focal Adhesion Kinase 2; D039421:Integrin alpha2; D039302:Integrin alphaVbeta3; D019869:Phosphatidylinositol 3-Kinases; D000081082:Phosphoinositide-3 Kinase Inhibitors; D011493:Protein Kinase C; D011505:Protein-Tyrosine Kinases; D019908:Proto-Oncogene Proteins c-raf; D019311:Staurosporine; D042461:Vascular Endothelial Growth Factor A