Gene HEPACAM*, named based on its original site of identification - hepatocytes and the nature of its protein product - a cell adhesion molecule (CAM), was first discovered and characterised in
human liver and reported by Shali Shen (MD, PhD) in 2005.
The gene encodes a protein of 416 amino acids, designated as hepaCAM**, which is a new member of the
immunoglobulin superfamily
The immunoglobulin superfamily (IgSF) is a large protein superfamily of cell surface and soluble proteins that are involved in the recognition, binding, or adhesion processes of cells. Molecules are categorized as members of this superfamily ...
of
cell adhesion molecule
Cell adhesion molecules (CAMs) are a subset of cell surface proteins that are involved in the binding of cells with other cells or with the extracellular matrix (ECM), in a process called cell adhesion. In essence, CAMs help cells stick to each ...
s (
IgSF CAM). The main biological functions of hepaCAM include a) modulating cell-matrix adhesion and
migration
Migration, migratory, or migrate may refer to: Human migration
* Human migration, physical movement by humans from one region to another
** International migration, when peoples cross state boundaries and stay in the host state for some minimum l ...
, and b) inhibiting
cancer
Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. These contrast with benign tumors, which do not spread. Possible signs and symptoms include a lump, abnormal bl ...
cell growth.
[
(Note: *HEPACAM, gene name; **hepaCAM, protein name)
]
Discovery
Through differential screening of gene expression, over 200 genes were found to be either up- or down-regulated in a hepatocellular carcinoma patient. These genes were subsequently evaluated against a panel of human HCC specimens, leading to the identification of a novel gene HEPN1. Based on the sequence of HEPN1, the new gene HEPACAM was then isolated and characterised.
Characteristics and functions
Structurally, hepaCAM is a glycoprotein
Glycoproteins are proteins which contain oligosaccharide chains covalently attached to amino acid side-chains. The carbohydrate is attached to the protein in a cotranslational or posttranslational modification. This process is known as g ...
containing an extracellular domain with 2 Ig-like loops, a transmembrane region and a cytoplasmic domain.[ Matched to chromosome 11q24, gene HEPACAM is ubiquitously expressed in normal human tissues, with particularly high expression levels in the central nervous system (CNS), and is frequently suppressed in a variety of tumour types.] Functionally, hepaCAM is involved in cell-extracellular matrix interactions and growth control of cancer cells,[ and is able to induce differentiation of ]glioblastoma
Glioblastoma, previously known as glioblastoma multiforme (GBM), is one of the most aggressive types of cancer that begin within the brain. Initially, signs and symptoms of glioblastoma are nonspecific. They may include headaches, personality cha ...
cells. In cell signaling, hepaCAM directly interacts with F-actin and calveolin 1, and is capable of inducing senescence-like growth arrest via a p53/p21-dependent pathway.[ Moreover, hepaCAM is proteolytically cleaved near the transmemberane region. These findings indicate that the new Ig-like cell adhesion molecule hepaCAM is also a tumour suppressor.]
Other names
#glialCAM, which was cloned from a human brain cDNA library in 2008 and found to be identical to hepaCAM; and
#HEPACAM1, when HEPACAM2 emerged in 2010.
About HEPACAM 2
Metastatic canine
Canine may refer to:
Zoology and anatomy
* a dog-like Canid animal in the subfamily Caninae
** '' Canis'', a genus including dogs, wolves, coyotes, and jackals
** Dog, the domestic dog
* Canine tooth, in mammalian oral anatomy
People with the ...
mammary carcinoma and their metastases are characterized by decreased HEPACAM2 but unchanged HEPACAM2 expression levels when compared to normal glands.[
]
References
{{DEFAULTSORT:Hepacam
Breast cancer
Immunoglobulin superfamily
Tumor suppressor genes