Epithelial cell adhesion molecule (EpCAM, also known as CD326 or TACSTD1), is a type I transmembrane glycoprotein, consisting of 314 amino acids with 40 kDa in molecular weight. EpCAM is comprised of an extracellular domain with epidermal growth factor (EGF) and thyroglobulin repeat-like domains, a single transmembrane domain, and a short 26-amino acid intracellular domain called EpICD. Two EpCAM subunits form a heart-shaped dimer on the cell surface. EpCAM is expressed in a variety of human epithelial tissues, cancers, progenitor, and stem cells, and is also a cell surface marker on the various stem and progenitor cells. EpCAM is highly expressed in epithelial cancer, including colon and breast cancer.
Intracellular EpCAM is cleaved by two important proteins named tumor necrosis factor α converting enzyme (TACE) and peresenilin 2 (PS-2) as EpEX and EpICD. EpEX is released out of the cell, whereas EpICD is released into the cytoplasm. Meanwhile, β-Catenin accumulates in the cytoplasm due to the inhibition of the β-Catenin degradation complex (AXIN, GSK3β, APC) in the Wnt-β-Catenin pathway. With help of four and one-half LIM domain protein 2 (FHL2), EpICD and β-Catenin enter into the nucleus. These nuclear complex proteins regulate gene transcription and activate the EpCAM target gene such as Cyclins and C-myc. In addition, the release of soluble EpEX may then trigger an autocrine cell-signaling response.
Fig.1 Signaling pathways of EpCAM. (Munz, 2009)
EpCAM is an attractive target for tumor diagnosis and therapy because of its tumor-specific overexpression. EpCAM, also called tumor-associated calcium signal transducer protein 1-precursor (TACSTD1), is a marker for most epithelial cancer. EpCAM levels are increased in most epithelium-derived tumors. High expression levels of EpCAM usually correlate with poor prognosis, such as in breast cancer, ovarian cancer, and pancreatic. EpCAM has been used as a target for many immunotherapeutic approaches, including treatment with monoclonal antibodies, the development of cancer-targeting antibodies, and vaccination strategies.
EpCAM is a pan-epithelium marker, which is expressed in a great variety of differentiated epithelia. Importantly, EpCAM is the central target molecule for the enrichment and characterization of systemic tumor cells with prognostic and metastatic potential. Creative Biolabs provides a full set of EpCAM assay portfolio services for research, including but not limited to:
Creative Biolabs provides a complete portfolio of tumor marker assays such as EpCAM assay portfolio service. We are continually expanding our portfolio by adding new tumor marker assays and applications and broadening our network with competent partners. Our goal is to help our clients to achieve research goals as quickly and as easily as possible. Please feel free to contact us.
For Research Use Only | Not For Clinical Use
Download our brochure