Investigation of the marine compound spongistatin 1 links the inhibition of PKCalpha translocation to nonmitotic effects of tubulin antagonism in angiogenesis.
The aims of the study were to meet the demand of new tubulin antagonists with fewer side effects by characterizing the antiangiogenic properties of the experimental compound spongistatin 1, and to elucidate nonmitotic mechanisms by which tubulin antagonists inhibit angiogenesis. Although tubulin-inhibiting drugs and their antiangiogenic properties have been investigated for a long time, surprisingly little is known about their underlying mechanisms of action. Antiangiogenic effects of spongistatin 1 were investigated in endothelial cells in vitro, including functional cell-based assays, live-cell imaging, and a kinome array, and in the mouse cornea pocket assay in vivo. Spongistatin 1 inhibited angiogenesis at nanomolar concentrations (IC(50): cytotoxicity>50 nM, proliferation 100 pM, migration 1.0 nM, tube formation 1.0 nM, chemotaxis 1.0 nM, aortic ring sprouting 500 pM, neovascularization in vivo 10 microg/kg). Further, a kinome array and validating data showed that spongistatin 1 inhibits the phosphorylation activity of protein kinase Calpha (PKCalpha), an essential kinase in angiogenesis, and its translocation to the membrane. Thus, we conclude that PKCalpha might be an important target for the antiangiogenic effects of tubulin antagonism. In addition, the data from the kinase array suggest that different tubulin antagonists might have individual intracellular actions.
Rothmeier
Andrea S
AS
Department of Pharmacy, Center for Drug Research, University of Munich, Munich, Germany.
Ischenko
Ivan
I
Joore
Jos
J
Garczarczyk
Dorota
D
Fürst
Robert
R
Bruns
Christiane J
CJ
Vollmar
Angelika M
AM
Zahler
Stefan
S
D020533:Angiogenesis Inhibitors / Q000378:metabolism / Q000494:pharmacology*; D000818:Animals; D001012:Aorta, Abdominal / Q000187:drug effects; D002465:Cell Movement / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D002633:Chemotaxis / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D042783:Endothelial Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D004727:Endothelium / Q000166:cytology; D006801:Humans; D007150:Immunohistochemistry; D020128:Inhibitory Concentration 50; D018942:Macrolides / Q000494:pharmacology*; D051379:Mice; D008815:Mice, Inbred Strains; D008870:Microtubules / Q000187:drug effects; D018919:Neovascularization, Physiologic / Q000187:drug effects*; D010766:Phosphorylation / Q000187:drug effects; D011161:Porifera / Q000737:chemistry; D051571:Protein Kinase C-alpha / Q000037:antagonists & inhibitors*; D014162:Transfection; D014404:Tubulin / Q000378:metabolism*; D014471:Umbilical Veins / Q000166:cytology; D000095702:Polyether Toxins
D020533:Angiogenesis Inhibitors; D018942:Macrolides; D051571:Protein Kinase C-alpha; D014404:Tubulin; C083856:spongistatin 1; D000095702:Polyether Toxins