Angiogenesis and Cancer

Abstract

Tumors measuring 1-2 (mm)3 lack blood supply and neovascularization is a major process orchestrated by over-production and release of pro-angiogenic growth factors causing sequential step-wise formation of blood vessel capillaries in tumors.Moleculars mediators of tumors angiogenesis include VEGF family, IL-8, EGF receptor ligands, basic and acidic FGF, PDGF etc. There are natural endogenenous inhibitors of tumorigenesis (TSP-1,Vasostatin).Negative feedback mechanisms do exist to control/regulate tumor angiogenesis. Angiogeneis is detrimental to tumor progression favouring transition from hyperplasia to a neoplastic state, influencing cancer cell dissemination besides exerting an independent negative prognosis. Tumor vasculature is dysfunctional, heterogeneous in the tumor mass interms of density leading to a limited/retarded diffusion of drugs especially certain antibodies,gene therapy vectors, immune-effector cells through interstitium of these tumors. The hypoxic zones in tumors are the areas of resistance to the chemotherapy. Angiogenesis is upregulated in tumorigenesis leading to over-production of proangiogenic growth factors that have become targets for anticancer drug development.  J Med Sci.2009;12(2):32-33