Human Carcinoembryonic Antigen-Related Cell Adhesion Molecule 5 (CEACAM5) Protein

Background

CEACAM5, also known as carcinoembryonic antigen (CEA), is a glycoprotein member of the immunoglobulin superfamily that plays a prominent role in cell adhesion, immune modulation, and intercellular signaling. It is highly expressed in epithelial tissues and is overexpressed in various cancers, including colorectal, pancreatic, and lung cancers, where it is used as a tumor marker for diagnosis, prognosis, and monitoring therapeutic responses. CEACAM5 mediates homophilic and heterophilic adhesion, influencing cellular aggregation, invasion, and metastasis. It interacts with other CEACAM family members and cell surface receptors to regulate signaling pathways involved in cell proliferation, migration, and immune evasion. Structurally, CEACAM5 contains multiple immunoglobulin-like domains, a glycosylphosphatidylinositol (GPI) anchor, and extensive glycosylation sites that contribute to its functional diversity. In cancer, CEACAM5 promotes tumor progression by enhancing adhesion to extracellular matrix components and modulating immune responses, such as inhibiting T-cell activation. Therapeutic strategies targeting CEACAM5, including monoclonal antibodies and vaccines, are under development to exploit its role as a biomarker and driver of tumor progression. CEACAM5 also plays roles in physiological processes like epithelial cell polarity and tissue homeostasis, reflecting its multifaceted importance.