TEM8/ANTXR1 Blockade Inhibits Pathological Angiogenesis and Potentiates Tumoricidal Responses against Multiple Cancer Types

SummaryCurrent antiangiogenic agents used to treat cancer only partially inhibit neovascularization and cause normal tissue toxicities, fueling the need to identify therapeutic agents that are more selective for pathological angiogenesis. Tumor endothelial marker 8 (TEM8), also known as anthrax toxin receptor 1 (ANTXR1), is a highly conserved cell-surface protein overexpressed on tumor-infiltrating vasculature. Here we show that genetic disruption of Tem8 results in impaired growth of human tumor xenografts of diverse origin including melanoma, breast, colon, and lung cancer. Furthermore, antibodies developed against the TEM8 extracellular domain blocked anthrax intoxication, inhibited tumor-induced angiogenesis, displayed broad antitumor activity, and augmented the activity of clinically approved anticancer agents without added toxicity. Thus, TEM8 targeting may allow selective inhibition of pathological angiogenesis.

► Host-derived TEM8 promotes the growth of multiple human tumor xenografts
► Anti-TEM8 mAbs selectively block tumor angiogenesis and tumor growth
► Toxicity is not observed following TEM8-specific blockade
► Anti-TEM8 mAbs augment the activity of various anti-cancer agents