What are Receptor Tyrosine Kinases and Why are They Important in Cancer Research?

Receptor tyrosine kinases (RTKs) are a type of cell-surface receptors and are often important in certain types of human cancer. These proteins are receptors for peptide/protein hormones including nerve growth factor (NGF), platelet derived growth factor (PDGF), fibroblast growth factor (FGF), epidermal growth factor (EGF), insulin and other cytokines/chemokines/growth factors. The active form of an RTK is phosphorylated at a tyrosine site.

Following are five important things to know about RTKs:

1. Certain drugs, such as gefitinib, prevent the functioning of receptor tyrosine kinases. In the case of gefitinib, it inhibits a tyrosine kinase that is important in the development of non-small cell lung cancer.
2. There are 90 unique tyrosine kinase genes identified in the human genome, of which 58 encode receptor tyrosine kinase proteins. Multiplex assays are a convenient way to study the large number of possible kinases involved in important cellular activities.
3. RTKs are key regulators of normal cellular processes such as regulating cell survival, proliferation, and motility.
4. In certain types of cancer there are often multiple RTKs involved in a single oncogenic pathway, making it necessary to be able to study multiple RTKs in a single assay in order to gain the best understanding of their mechanism of action.
5. RTKs are important cancer biomarkers and are high-affinity cell surface receptors for cytokines/chemokines/growth factors.

Since their discovery in the early 1990s, RTKs have been continuing to play an important role in cancer research and other cell signaling based events.

How is your lab monitoring RTKs in cell signaling research? What methods do you use?