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.