ABSTRACT

Angiogenesis and Cancer Angiogenesis is an essential feature of tumor growth and metastasis (Folkman, 1971). Tumor cells induce angiogenesis both by direct stimulation of endothelial cells as well as by the secretion of several growth factors: vascular endothelial growth factor (VEGF), platelet-derived growth factor (PDGF), and insulin-like growth factor (IGF). Of the identified angiogenic factors, VEGF is the most potent and most specific and has been identified as a crucial regulator of both normal and pathologic angiogenesis (Ferrara and Davis-Smyth, 1997). VEGF binds to specific receptors on cell surfaces, resulting in cellular proliferation, cell migration, and tumor growth. The neovascularization of tumors occurs through the enhanced expression of VEGF (Ferrara et al., 2003). The VEGF family is comprised of a number of ligands, VEGF-A, B, C, D, E and placental growth factor (PLGF). VEGF-A is the most potent stimulator of angiogenesis.