Antiangiogenic activity of herboxidiene via downregulation of vascular endothelial growth factor receptor-2 and hypoxia-inducible factor-1α

Antiangiogenesis is now thought of as one of the most important approaches for anticancer therapy. In this study, we determined the antiangiogenic property of herboxidiene, a polyketide natural product. Herboxidiene effectively inhibited the proliferation of human umbilical vein endothelial cells (HUVECs) at concentrations not exhibiting cytotoxicity. Furthermore, the natural product significantly suppressed vascular endothelial growth factor-induced invasion and tube formation in HUVECs as well as neovascularization of the chorioallantoic membrane in developing chick embryos. We also identified an association between the antiangiogenic activity of herboxidiene and the downregulation of both the phosphorylation of VEGF receptor 2 (KDR/Flk-1) and the expression of hypoxia-inducible factor-1 alpha at the transcriptional level. These results suggest that herboxidiene functions as a potential antiangiogenic agent and may be applicable for anticancer therapy by targeting tumor angiogenesis.