Signalling Pathways and Adhesion Molecules as Targets for Antiangiogenesis Therapy in Tumors

In the embryo, blood vessels derive from endothelial precursors in a process called vasculogenesis. These progenitors assemble into a primitive vascular plexus. Subsequently, in a process called angiogenesis, the primitive vascular plexus expands by means of vessel sprouting and organizes into a network of blood vessels. Finally, the developing vessels are reinforced by the association with pericytes and smooth muscle cells (Coultas, et al. 2005). In parallel, in a process called lymphangiogenesis, lymphatic endothelial cells, which derive from embryonic veins by sprouting, form primary lymph sacs and the primary lymphatic plexus (Alitalo and Carmeliet 2002).