Epidermal Growth Factor Receptor (EGFR) is a type of transmembrane protein located on the surface of cells that belongs to the family of Receptor Tyrosine Kinases (RTKs). The EGFR protein is activated by binding with specific extracellular ligands such as epidermal growth factor (EGF), transforming growth factor-alpha (TGF-α), and others. Once activated, EGFR initiates a complex signaling cascade, which can lead to the activation of a variety of intracellular pathways, including the RAS/RAF/MEK/ERK and PI3K/AKT/mTOR pathways.
EGFR is involved in a range of cellular processes, including cell growth, proliferation, differentiation, migration, and survival. EGFR is expressed in various tissues, including the skin, lung, and gastrointestinal tract. Aberrant EGFR activation has been linked to the development and progression of many types of cancers, including non-small cell lung cancer, colorectal cancer, and pancreatic cancer.
Therapies that target EGFR signaling, such as monoclonal antibodies and tyrosine kinase inhibitors, have been developed and are used in the treatment of some cancers. However, resistance to these therapies can develop over time, and ongoing research is focused on identifying new treatment strategies for cancers with EGFR dysregulation.