CXC and CC Chemokines as Angiogenic Modulators in Nonhaematological Tumors

Figure 2

The transcription factor TWIST1 promotes angiogenesis and tumor progression without increasing the secretion of VEGF but rather by inducing the expression of the macrophage chemoattractant CCL2. Tumor cells that express Twist1 upregulate CCL2 transcript, increase CCL2 protein levels, and lead to the formation of a CCL2 gradient in tumor microenvironment. This gradient attracts macrophages, which promote tumor angiogenesis.