Role of Angiogenesis and Its Biomarkers in Development of Targeted Tumor Therapies

Figure 2

“Angiogenic switch” balance hypothesis. The angiogenic balance between angiogenic activators and inhibitors tightly regulates angiogenic switch mechanism. Upregulation of angiogenic inhibitors and angiogenic activators downregulation, spark angiogenesis leading to increased blood vessels formation. Reduction of inhibitor concentration i.e., angiostatin, restin, thrombospondin, and increasing the activator level i.e., vascular endothelial growth factor (VEGF); basic fibroblast growth factor (bFGF); placenta growth factor (PGF); interleukin-8 (IL-8) could induce the growth of novel blood vessels.