Hepatocyte Cell Adhesion Molecule (HEPACAM)

A HEPACAM cDNA, isolated from liver, encodes a deduced 416-amino acid protein with the typical structure of Ig-like adhesion molecules, including 2 extracellular Ig-like domains, a transmembrane segment, and a cytoplasmic tail containing putative SH3 binding sites and potential serine/threonine and tyrosine kinase phosphorylation sites. RT-PCR demonstrated expression of HEPACAM in normal liver tissues, downregulated expression in hepatocellular carcinoma (HCC) tissues, and undetectable expression in HCC cell lines.

Western blot analysis demonstrated that HEPACAM is glycosylated. A polyclonal antibody raised against the cytoplasmic domain of HEPACAM indicated that this domain is phosphorylated. Moh et al. (2005) suggested that HEPACAM may be a tumor suppressor in HCC.