Inhibiting the inhibitor: Targeting vascular endothelial protein tyrosine phosphatase to promote tumor vascular maturation

摘要

A landmark article by Goel et al. (1) entitled "Effects of Vascular-Endothelial Protein Tyrosine Phosphatase Inhibition on Breast Cancer Vasculature and Metastatic Progression" is included in this issue of the Journal. In this study, the investigators tested the effects of AKB-9778, a novel, potent, and selective inhibitor of vascular endothelial protein tyrosine phosphatase (VE-PTP), on tumor growth and angiogenesis. VE-PTP (also known as PTPRB, HPTP(3, or RPTPBeta) was only recently identified as an important player in the molecular regulation of angiogenesis (2,3), and in this regard it provides a new therapeutic target in our assault on tumor angiogenesis. VE-PTP's role in the endothelium has been linked most closely to its ability to selectively dephosphorylate and inactivate Tie2 (4), a receptor tyrosine kinase expressed primarily on endothelial cells (ECs) (5).