HEPACAM (also known as GlialCAM) is a gene located on chromosome 11q24 that encodes the hepatic and glial cell adhesion molecule. It is a single-pass type I transmembrane glycoprotein and a member of the immunoglobulin superfamily. It functions primarily as a homodimer to regulate cell-to-cell adhesion, cell motility, and interactions with the extracellular matrix (ECM).
Research strongly implicates HEPACAM as a tumor suppressor because its expression is frequently downregulated, silenced, or entirely absent across a wide variety of human cancers. 🧬 Role in Tumor Suppression
When functioning normally, HEPACAM acts as a “molecular brake” to keep cellular behavior in check:
Growth Inhibition & Senescence: Reintroducing HEPACAM into transformed cancer cell lines reduces cellular growth and induces senescence-like growth arrest. It is known to trigger this arrest via a p53/p21-dependent cell signaling pathway.
Stabilizing Connexin 43: HEPACAM associates with and stabilizes Connexin 43, a main component of gap junctions. Connexin 43 is itself a well-known tumor suppressor. In the absence of HEPACAM, Connexin 43 degrades prematurely via the lysosomal pathway, which can promote tumor progression.
Suppressing Invasion and Migration: Overexpressing HEPACAM promotes cancer cell apoptosis (programmed cell death) while directly inhibiting the cells’ ability to migrate and invade surrounding tissues. ♋ Relevance in Specific Cancers HEPACAM gene Hepatic And Glial Cell Adhesion Molecule