Acute, but not constitutive, loss of endothelial β3-integrin inhibits tumour growth and angiogenesis

Background Angiogenesis, the formation of new vessels from pre-existing ones, is essential for tumour growth and metastasis. Endothelial cells play a central role in this process: they drive blood vessel formation in response to signals from the local environment, by a mechanism that is integrindependent. We are particularly interested in understanding what role avb3-integrin plays in governing tumour angiogenesis. avb3-integrin seemingly poses an ideal anti-angiogenic target. Its expression is vastly up-regulated in neo-angiogenic vessels, while its expression in quiescent vasculature is minimal. However, anti-angiogenic therapy targeting avb3-integrin has proven somewhat disappointing. In part this likely relates to the fact that avb3-integrin is not expressed solely by endothelial cells, but across a wide range of cell types that each contribute to angiogenesis. The aim of the research we present here is to elucidate the role of avb3-integrin in tumour growth and angiogenesis as it is expressed specifically by endothelial cells.