Epithelial cell adhesion molecule (EpCAM) is a protein

Protein

Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...

 that in humans is encoded by the EPCAM gene

Gene

A gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains...

. EpCAM has also been designated as TACSTD1 (tumor-associated calcium signal transducer 1) and CD326 (cluster of differentiation

Cluster of differentiation

The cluster of differentiation is a protocol used for the identification and investigation of cell surface molecules present on white blood cells, providing targets for immunophenotyping of cells...

 326).

Function

EpCAM is a pan-epithelial differentiation antigen

Antigen

An antigen is a foreign molecule that, when introduced into the body, triggers the production of an antibody by the immune system. The immune system will then kill or neutralize the antigen that is recognized as a foreign and potentially harmful invader. These invaders can be molecules such as...

 that is expressed on almost all carcinomas. Its constitutional function is being elucidated. It is intricately linked with the Cadherin

Cadherin

Cadherins are a class of type-1 transmembrane proteins. They play important roles in cell adhesion, ensuring that cells within tissues are bound together. They are dependent on calcium ions to function, hence their name.The cadherin superfamily includes cadherins, protocadherins, desmogleins, and...

-Catenin

Catenin

Catenins are proteins found in complexes with cadherin cell adhesion molecules of animal cells. The first two catenins that were identified became known as alpha-catenin and beta-catenin. Alpha-catenin can bind to beta-catenin and can also bind actin. Beta-catenin binds the cytoplasmic domain of...

 pathway and hence the fundamental WNT pathway responsible for intracellular signalling and polarity. It has been used as an immunotherapeutic target in the treatment of gastrointestinal, urological and other carcinomas. It is expressed in undifferentiated pluripotent stem cells.

It is identical with the 17-1A antigen.

Clinical significance

EpCAM is a carcinoma-associated antigen and is a member of a family that includes at least two type I membrane proteins. This antigen is expressed on most normal epithelial cells and gastrointestinal carcinomas and functions as a homotypic calcium-independent cell adhesion molecule

Cell adhesion molecule

Cell Adhesion Molecules are proteins located on the cell surface involved with the binding with other cells or with the extracellular matrix in the process called cell adhesion....

. The antigen is being used as a target for immunotherapy treatment of human carcinomas.

Edrecolomab

Edrecolomab

Edrecolomab is a mouse-derived monoclonal antibody targeting the cell-surface glycoprotein EpCAM , which is expressed on epithelial tissues and on various carcinomas....

, catumaxomab

Catumaxomab

Catumaxomab is a rat-mouse hybrid monoclonal antibody which is used to treat malignant ascites, a condition occurring in patients with metastasizing cancer. It binds to antigens CD3 and EpCAM. It is in clinical trials in the United States currently and is used in Europe...

 and other monoclonal antibodies

Monoclonal antibodies

Monoclonal antibodies are monospecific antibodies that are the same because they are made by identical immune cells that are all clones of a unique parent cell....

 are designed to bind to it.

External links

• FAQs on HNPCC from the National Institute of Health
• GeneReviews/NCBI/NIH/UW entry on Lynch syndrome