Decorin antagonizes the angiogenic network: concurrent inhibition of Met, hypoxia inducible factor 1?, vascular endothelial growth factor A, and induction of thrombospondin-1 and TIMP3.

ABSTRACT: Decorin, a small leucine-rich proteoglycan, inhibits tumor growth by antagonizing multiple receptor tyrosine kinases including EGFR and Met. Here, we investigated decorin during normoxic angiogenic signaling. An angiogenic PCR array revealed a profound decorin-evoked transcriptional inhibition of pro-angiogenic genes, such as HIF1A. Decorin evoked a reduction of hypoxia inducible factor (HIF)-1? and vascular endothelial growth factor A (VEGFA) in MDA-231 breast carcinoma cells expressing constitutively-active HIF-1?. Suppression of Met with decorin or siRNA evoked a similar reduction of VEGFA by attenuating downstream ?-catenin signaling. These data establish a noncanonical role for ?-catenin in regulating VEGFA expression. We found that exogenous decorin induced expression of thrombospondin-1 and TIMP3, two powerful angiostatic agents. In contrast, decorin suppressed both the expression and enzymatic activity of matrix metalloprotease (MMP)-9 and MMP-2, two pro-angiogenic proteases. Our data establish a novel duality for decorin as a suppressor of tumor angiogenesis under normoxia by simultaneously down-regulating potent pro-angiogenic factors and inducing endogenous anti-angiogenic agents.

SUBMITTER: Neill T 

PROVIDER: S-EPMC3285326 | biostudies-literature | 2012 Feb

REPOSITORIES: biostudies-literature