Angiogenesis switch

Blocking angiogenesis is a popular therapeutic strategy, but the intracellular switch that governs whether blood vessels grow or regress was not identified until very recently. In May, researchers at Harvard Medical School published in The EMBO Journal evidence that the intracellular signaling molecules PI3K and PLC gamma compete for the substrate PI45P2 and that the result determines whether blood vessels grow or regress.

Phosphoinositide 3-kinase (PI3K) is known to play a role in angiogenesis and is widely considered to be a hot target in cancer. But the finding that PI3K competes with phospholipase C (PLC) gamma for PI45P2 (phosphatidylinositol-4,5-bisphosphate) and can directly turn on angiogenesis had not been previously reported, according to Gordon Mills, chairman of the Department of Molecular Therapeutics at The University of Texas. Mills co-authored a review paper on PI3K signaling in Nature Reviews in December 2005...