Flk-1 as a target for tumor growth inhibition.
A number of growth factor receptor tyrosine kinases have been implicated in angiogenesis, including epidermal growth factor receptor, fibroblast growth factor receptor, platelet-derived growth factor receptor, Flk-1/KDR, Flt-1, Tie-1, and Tek/Tie-2. Flk-1/KDR, a receptor for vascular endothelial growth factor (VEGF), is expressed exclusively in endothelial cells. Using dominant-negative methods, Flk-1 was shown to play a role in angiogenesis and the growth of a variety of tumor types. Because of this, a drug discovery effort was established to identify Flk-1 kinase inhibitors. For initial screening, an ELISA in, a 96-well format was used to measure VEGF-induced Flk-1 tyrosine phosphorylation in whole cells. Compounds that inhibited ligand-induced receptor autophosphorylation were confirmed by antiphosphotyrosine immunoblotting. Inhibition of VEGF-stimulated DNA synthesis in human endothelial cells was also assessed. Inhibitors were further evaluated for their effects on vessel formation using the chorioallantoic membrane assay. Using these methods, antiangiogenesis compounds that inhibit Flk-1 tyrosine kinase activity, endothelial cell mitogenesis, and blood vessel formation in the chorioallantoic membrane assay have been found.
Strawn
L M
LM
SUGEN, Inc., Redwood City, California 94063, USA.
McMahon
G
G
App
H
H
Schreck
R
R
Kuchler
W R
WR
Longhi
M P
MP
Hui
T H
TH
Tang
C
C
Levitzki
A
A
Gazit
A
A
Chen
I
I
Keri
G
G
Orfi
L
L
Risau
W
W
Flamme
I
I
Ullrich
A
A
Hirth
K P
KP
Shawver
L K
LK
D016475:3T3 Cells / Q000187:drug effects / Q000201:enzymology; D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology*; D015815:Cell Adhesion Molecules / Q000032:analysis; D002455:Cell Division / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D002642:Chick Embryo; D016228:Endothelial Growth Factors / Q000494:pharmacology; D004730:Endothelium, Vascular / Q000187:drug effects / Q000201:enzymology; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D015151:Immunoblotting; D008222:Lymphokines / Q000494:pharmacology; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D018919:Neovascularization, Physiologic / Q000187:drug effects; D010766:Phosphorylation; D020794:Receptor Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D017978:Receptors, Growth Factor / Q000037:antagonists & inhibitors* / Q000378:metabolism; D040262:Receptors, Vascular Endothelial Growth Factor; D013268:Stimulation, Chemical; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors
D000970:Antineoplastic Agents; D015815:Cell Adhesion Molecules; D016228:Endothelial Growth Factors; D004791:Enzyme Inhibitors; D008222:Lymphokines; D017978:Receptors, Growth Factor; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors; D020794:Receptor Protein-Tyrosine Kinases; D040262:Receptors, Vascular Endothelial Growth Factor