Angiopoietins in Glioblastoma Angiogenesis

(Medizinische Hochshule Hannover, 2013

 

 

Angiopoietins are a family of growth factors that works with VEGF promoting angiogenesis and tumor formation (Brunckhorst et al, 2010). Angiopoietin 1-2 bind to Tie-2 (tyrosine kinase). Angiopoietin 1, secreted from pericytes, plays a role in maturation and stabilization of the tumor vasculature (Choudhury et al, 2010).                 

Tumor cells cause Tie-2 receptor phosphorylation, which stabilizes VEGF-A (Hawighorst et al, 2002) inducing vasculature, endothelial cell sprouting, migration, and survival (Sako et al, 2008).                                 

Angiopoietin-2 expressed by endothelial cells (Hegen et al, 2004) has destabilizing ion effects on Ang-1/Tie-2 facilitating neovasculation and vessel sprouting in the presence of VEGF-A (Asahara et al, 1998). In the absence of VEGF, vessel regression and endothelial cell apoptosis is induced (Choudhury et al, 2010).