Gastric M1 mucin, an early oncofetal marker of colon carcinogenesis, is encoded by the MUC5AC gene

Int J Cancer. 1998 Mar 2;75(5):767-73. doi: 10.1002/(sici)1097-0215(19980302)75:5<767::aid-ijc17>;2-3.


Gastric M1 mucin and the MUC5AC gene show a similar oncofetal expression in the colon. Our aim was to determine whether M1 mucin is the product of the MUC5AC gene. A recombinant baculovirus encoding the C-terminal portion of the MUC5AC gene as a fusion protein was isolated and the immunoreactivity of the recombinant mucin (rM) toward M1 antibodies studied. Chicken antibodies also were raised against purified rM. Besides its reactivity with L56/C, a serum recognizing the bacterially expressed MUC5AC gene product, rM was endowed with M1 immunoreactivity: (i) rM-expressing cells were stained specifically with anti-M1 serum and with the monoclonal antibody (MAb) 21M1, defining the M1-f epitope; (ii) both L56/C and anti-M1 antibodies recognized the same bands in immunoblots of rM-containing cell extracts; (iii) the 21M1 antibody reacted with rM in an immunoradiometric assay. Among the 7 M1 epitopes, M1-f was the only one encoded by the 3' portion of the MUC5AC gene. It was the only epitope detected in a native mucin M1-derived 170 kDa bromelain proteolytic fragment. Furthermore, the staining patterns of human tissues obtained with either anti-rM chicken antibodies or anti-M1 antibodies were identical. We conclude that M1 immunoreactivity is encoded at least in part by the MUC5AC gene.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antigens, Neoplasm / genetics*
  • Baculoviridae
  • Chickens
  • Epitope Mapping
  • Fluorescent Antibody Technique, Indirect
  • Humans
  • Immunologic Techniques
  • Mice
  • Mucin 5AC
  • Mucins / genetics*
  • Rabbits
  • Rats
  • Recombinant Fusion Proteins
  • Spodoptera


  • Antigens, Neoplasm
  • MUC5AC protein, human
  • Muc5ac protein, mouse
  • Muc5ac protein, rat
  • Mucin 5AC
  • Mucins
  • Recombinant Fusion Proteins
  • gastro-intestinal mucus-associated antigens
  • oncofetal antigens