Epiregulin

Epiregulin is member of the epidermal growth factor (EGF) family which is a 46-amino-acid single chain polypeptide, and its amino acid sequence exhibited 24-50% amino acid sequence identity with sequences of other EGF-related growth factors. Epiregulin binds to the EGF receptor EGFR and ErbB4 and can stimulate signaling of ErbB2 and ErbB3 through ligand-induced heterodimerization with a cognate receptor, leading to activation of downstream Ras-Raf-mitogen activated protein kinase (MAPK)-extracellular signal-regulated kinase (ERK) as well as the PI3K-Akt pathways to increase cellular proliferation. Epiregulin exhibited bifunctional regulatory properties: it inhibited the growth of several epithelial tumor cells and stimulated the growth of fibroblasts and various other types of cells. Epiregulin has been shown to promote wound healing in oral epithelium, enhance proliferation of other epithelial tissues, and is involved in several epithelial-related malignancies such as colorectal, lung, and bladder carcinoma.