CD66e; carcinoembryonic antigen-related cell adhesion molecule 5; carcinoembryonic antigen; CEA; meconium antigen 100; CD66e (CEACAM5, CEA)

Function

• suggestion CEA may be the fetal counterpart of albumin seems unlikely if CEA is a glypiated protein
• cell surface glycoprotein
• plays a role in cell adhesion & in intracellular signaling

Structure

• homodimer
• complex immunoreactive glycoprotein with a MW of 180 kD
• contains 60% carbohydrate
• belongs to the immunoglobulin superfamily, CEA family
• contains 7 Ig-like (immunoglobulin-like) domains

Compartment

cell membrane; lipid-anchor, GPI-anchor

Expression

• neutrophils
• fetal colon
• small intestinal crypts
• apical surfaces of epithelial cells
• small intestinal goblet cell mucin (not intracytoplasmic)
• biliary tract

Pathology

• expressed in:
  • adenocarcinomas of endodermally derived GI epithelium
  • lung adenocarcinoma
  • colon adenocarcinoma
  • medullary thyroid carcinoma*
• not expressed in:
  • hepatocellular carcinoma
  • mesothelioma
  • renal cell carcinoma
  • prostate adenocarcinoma
  • ovarian carcinoma
  • other thyroid carcinomas* stain negatively with antibody
• receptor for E.coli Dr adhesins; binding of E.coli Dr adhesins leads to dissociation of the homodimer

Diagnostic use: 85% sensitive, 96% specific for lung adenocarcinoma vs. mesothelioma

Notes

• gene originally CEA, renamed CEACAM5

More general terms

• CD antigen
• glypiated protein
• carcinoembryonic antigen (CEA) family

Additional terms

• carcinoembryonic antigen (CEA) in serum/plasma

Database

• UniProt: http://www.uniprot.org/uniprot/P06731.html
• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=1048
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:1048
• OMIM: https://mirror.omim.org/entry/114890