Molecular regulation mechanism of tumor sprouting angiogenesis

Sprouting angiogenesis is the primary way of tumor angiogenesis. The diverse pathways and molecules have been involved in angiogenesis,the formation of new blood vessels.VEGF-A / VEGFR-2 has recently emerged as a key signal axis of angiogenesis. Moreover,VEGFR-3 which is highly expressed in the tumor vascular endothelial,plays a bimodal role in regulating angiogenesis by effectively controlling the number of vessel branches and endothelial sprouts. The balance of VEGF / VEGFR and Dll4 / Notch1 signaling pathways is significant in the sprouting angiogenesis. The process of sprouting has been regulated by the intersection of VEGF / VEGFR signaling with other pathways,including angiopoietin / Tie,hypoxia-inducible factor,and integrin pathways. Thus,focuse on the initial stage of sprouting will be effective strategies for tumor anti-angiogenesis.