Authors: (Yiguo Hu, Shaoguang Li - The Jackson Laboratory, Bar Harbor Maine)
Abstract: A protein kinase is an enzyme that modifies other proteins by chemically adding phosphate groups to them (phosphorylation). Phosphorylation usually results in a functional change of the target protein (substrate) by changing enzyme activity, cellular location, or association with other proteins. Protein tyrosine kinases (PTKs) play a key role in the regulation of cell proliferation, differentiation, metabolism, migration, and survival. Due to their involvement in various forms of cancers, PTKs have become prominent targets for therapy. There are two principles to developing PTK inhibitors. As binding APT is essential for kinase activity, the common strategy is to look for the small molecules that can compete the ATP binding sites. To increase specificity of PTK inhibitors, a more attractive strategy is to develop non-ATP-competitive kiniase inhibitors. So far, there are many PTK inhibitors that have been developed. Several inhibitors have been successfully used to treat human cancers in clinic. These agents are shown to inhibit multiple functions of cancer cells, including proliferation, survival, invasion, and angiogenesis.