The molecular perspective: VEGF and angiogenesis.

The Oncologist 2002;7:569-570 www.TheOncologist.com Our cells need a constant supply of oxygen to power their diverse molecular processes. This oxygen is delivered by the blood, so nearly all of our cells are within a tenth of a millimeter from a blood capillary. Tumor cells are no exception. If a collection of cancerous cells grows much larger than a millimeter, it will starve itself of oxygen and energy unless new blood vessels are built to provide a supply. For this reason, many cancer cells co-opt the normal processes of angiogenesis, the development of blood vessels, in order to build their own blood supply. Vascular endothelial growth factor, or VEGF (shown in Fig. 1), is the key signal used by oxygen-hungry cells to promote growth of blood vessels. It binds to specialized receptors on the surfaces of endothelial cells (shown in Fig. 2) and directs them to build new vessels. After receiving this message, the cells build specialized proteases to break through the basal lamina, and migrate into the oxygen-starved region. Fundamentals of Cancer Medicine The Oncologist