Fig. 5
Angiogenesis in cancer. Nutrient deprivation and hypoxia signal the necessity of oxygen and nutrients to the tumour mass and thus activate the process of angiogenesis through increased expression of proangiogenic genes including via HIF-1. This includes VEGF which results in vasodilation of pre-existing blood vessels via generation of nitric oxide, EGF, Ang1 and bFGF which stimulates proliferation, migration and assembly of the endothelium. Integrins αvβ3 and α5 mediate cell migration and spreading and PDGF recruits smooth muscle cells for the formation of a new basement membrane of forming vessels (produced with Microsoft® PowerPoint®) [34]