Summary
Angiogenesis, the development of new blood vessels from preexisting vessels, is a
key step in tumor growth, invasion and metastasis formation. Inhibition of tumor angiogenesis
is considered as an attractive approach to suppress cancer progression and spreading.
Adhesion receptors of the integrin family promote tumor angiogenesis by mediating
cell migration, proliferation and survival of angiogenic endothelial cells. Integrins
up regulated and highly expressed on neovascular endothelial cells, such as αVβ3 and
α5β1, have been considered as relevant targets for anti-angiogenic therapies. Small
molecular integrin antagonists or blocking antibodies suppress angiogenesis and tumor
progression in many animal models, and some of them are currently being tested in
cancer clinical trials as anti-angiogenic agents. COX-2 inhibitors exert anti-cancer
effects, at least in part, by inhibiting tumor angiogenesis. We have recently shown
that COX-2 inhibitors suppress endothelial cell migration and angiogenesis by preventing
αVβ3-mediated and cAMP/PKA-dependent activation of the small GTPases Rac and Cdc42.
Here we will review the evidence for the involvement of vascular integrins in mediating
angiogenesis and the role of COX-2 metabolites in modulating the cAMP/Protein Kinase
A pathway and αVβ3-dependent Rac activation in endothelial cells.
The pulication was partially financed by Serono Foundation for the Advancement of
Medical Sience.
Part of this paper was originally presented at the 2nd International Workshop on New
Therapeutic Targets in Vascular Biology from February 6–9, 2003 in Geneva, Switzerland.
Keywords
Adhesion receptors - integrins - cell-matrix interactions - endothelial cells - prostaglandins