Angiogenin

Angiogenin (ANG), also known as ribonuclease 5, is a small 123 amino acid protein encoded by the ANG gene in humans that was initially isolated from tumor cells. Due to approximately 35% sequence homology with pancreatic RNases, ANG is considered member of the pancreatic ribonuclease A superfamily. ANG induces angiogenesis after binding to actin on the surface of endothelial cells, and accumulates at the nucleolus where it stimulates ribosomal transcription. Under stress conditions, this protein translocates to the cytoplasm and hydrolyzes cellular tRNA resulting in reduced protein synthesis.

ANG not only regulates cell proliferation, migration, invasion, adhesion and/or differentiation in vitro, but also plays an important role in angiogenesis, tumorigenesis and neurodegeneration in vivo. ANG is considered an excellent cancer therapeutic target because of its ability to stimulate tumor angiogenesis and cancer cell proliferation during tumor growth. ANG inhibitors have been shown to inhibit tumor growth in various animal models, such as anti-human monoclonal antibodies, 26-2F, small compounds, neomycins and neoamines, siRNA, antisense, soluble binding proteins, and enzyme inhibition agent.