Angiopoietin 2 levels in sera of children with solid malignancies

Background: The Angiopoietins 1 and 2 (Ang1 and Ang2) are endothelial cell specific growth factors that act as ligands to the receptor Tie-2. Ang1 activates Tie-2, but the exact effect of Ang2 on the state of Tie-2 remains unclear. While Ang1 seems to play an important role in the remodeling of the primary vasculature in early development by promoting circumferential growth and stabilization of the vasculature, Ang2 apparently mediates a destabilizing signal and thus renders the vessels more plastic and susceptible to other angiogenic signals. In the adult organism, Ang2 expression is found wherever vascular rem…