Regulation of Angiogenesis by EZH2

While VEGF-targeted therapies are showing promise in clinical studies, new angiogenesis targets are needed to make additional gains. Here, we show that increased Zeste homologue 2 (EZH2) expression in either tumor cells or in tumor vasculature is predictive of poor clinical outcome. The increase in endothelial EZH2 is a direct result of VEGF stimulation and indicates the presence of a paracrine circuit that promotes angiogenesis by methylating and silencing vasohibin 1 (VASH1). EZH2 silencing in the tumor-associated endothelial cells resulted in inhibition of angiogenesis mediated by reactivation of VASH1, and reduced ovarian cancer growth. Combined, these data provide a new understanding of the regulation of tumor angiogenesis and support the potential for targeting EZH2 as a novel therapeutic approach. Pre-clinical study, DNA microarray (Illumina HumanHT-12)