Figure 1
From: The role of the orphan nuclear receptor COUP-TFII in tumorigenesis
A model of COUP-TFII in the tumour microenvironment. In blood endothelial cells, COUP-TFII represses VEGFR-1 expression, a decoy receptor that sequesters the VEGF ligand, and leads to reduction of VEGFR-2 signalling. In contrast, in the lymphatic endothelial cells, COUP-TFII directly enhances the expression of VEGFR-3 and Nrp2, and promotes VEGFR-3 signalling. Additionally, COUP-TFII also upregulates the expression of Ang-1 in pericytes, and Ang-1 serves as a paracrine signal to activate Tie2 receptors on the endothelial cells. Thus, COUP-TFII regulates angiogenesis and lymphangiogenesis via the VEGF/VEGFR and Ang-1/Tie2 signalling pathways within the tumour microenvironment.
