EGFR

Mitogen-activated protein kinases (MAPKs) are important signaling proteins needed to transmit and relay extracellular stimuli and to illicit intracellular responses (1). The MAPK family of proteins are serine/threonine kinases that are able to phosphorylate and activate downstream kinases in a signal cascade that regulates diverse cell responses such as gene expression, metabolism, apoptosis, and differentiation (1). Notable members of the MAPK family include ERK, JNK, and p38 (1).

EGF (epidermal growth factor) stimulates differentiation, proliferation and cell growth by binding to its receptor, EGFR. EGF was first discovered in the mouse submandibular gland in 1986 by Stanley Cohen of Vanderbilt University, leading to a Nobel Prize in Physiology and Medicine. Since then, EGF has been found in many tissues of the human body (including urine, saliva, plasma, milk, macrophages and platelets) and has been the subject of intense study in many areas of clinical research due to its many abilities.

The NF2 gene, also known as “Merlin”, was discovered through studies into Neurofibromatosis Type II, a rare genetic disease which causes formation of non-malignant, but life-limiting, brain tumors. NF2 encodes a cytoskeletal protein involved in extracellular signalling (i.e. cell-to-cell).

The Merlin protein belongs to the ezrin/radixin/moesin (ERM) family of tumour suppressor proteins. Encoded by the rather less imaginatively named Neurofibromin 2 (NF2) gene, it is thought to play a role in extracellular signal transduction, linking the cell cytoskeleton with membrane-bound proteins and suppressing several receptors, including the epidermal growth factor receptor (EGFR).