Cadherin-17 (SP183)

Cadherin-17, also called liver-intestinal (LI) cadherin or human peptide transporter-1, is a member of the cadherin superfamily. Unlike some classic cadherins, such as E-, N-, and P-cadherins, cadherin-17 has seven cadherin repeats instead of five within the extracellular domain and only 20 amino-acid residues in the cytoplasmic domain1-2. The markedly short cytoplasmic domain lacks homology with other cadherins and the adhesive function of cadherin-17 is not dependent on association with other cytoplasmic proteins. The subcellular distribution of cadherin-17 is also different from classic cadherins. In intestinal epithelial cells, E-cadherin is concentrated in adherens junctions whereas cadherin-17 is evenly distributed along the lateral contact area. Human normal tissues that are strongly stained with cadherin-17 include appendicular epithelium, colonic epithelium, and small intestinal epithelium1. Other normal human tissues are not stained with cadherin-171. The results above indicate cadherin-17 can be used as a marker for identification of primary sites of tumors. In-house studies have shown that cadherin-17 expression is usually diffuse and strong in colorectal adenocarcinomas, whereas it is usually focal or scattered in adenocarcinomas of the stomach, pancreas and bile duct, and is virtually absent in tumors of other anatomic sites.