ABSTRACT
All tumors need to generate their own blood supply in order to obtain sufficient oxygen and nutrients to grow beyond a volume of approximately 1 mm3.1 They achieve this through the complex processes of angiogenesis whereby endothelial cells proliferate in response to growth factors and invade the basal lamina, resulting in the budding of new vessels from the existing vasculature.2,3 The endothelial cells of tumor blood vessels are attractive targets for drug development because of their pivotal role in cancer cell survival, growth and metastasis and because they are more genetically stable, and potentially less likely to develop resistance to therapeutic agents than the tumor cells themselves.3 Furthermore, because endothelial cell targets are different from those targeted by chemotherapy agents, the potential for combination treatment can be evaluated.
