Ovarian cancer antigen CA125 is encoded by the MUC16 mucin gene

Int J Cancer. 2002 Apr 10;98(5):737-40. doi: 10.1002/ijc.10250.


Serum assays based on the CA125 antigen are widely used in the monitoring of patients with ovarian cancer; however very little is known about the molecular nature of the CA125 antigen. We recently cloned a partial cDNA (designated MUC16) that codes for a new mucin that is a strong candidate for being the CA125 antigen. This assignment has now been confirmed by transfecting a partial MUC16 cDNA into 2 CA125-negative cell lines and demonstrating the synthesis of CA125 by 3 different assays. Of the 3 antibodies (OC125, M11 and VK-8) tested on the transfected cells, only the first 2 were strongly positive, indicating the differential expression of the CA125 epitopes in these cells. The cloning and expression of CA125 antigen opens the way to an understanding of its function in normal and malignant cells.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • CA-125 Antigen / genetics*
  • CA-125 Antigen / metabolism
  • DNA, Complementary / genetics
  • Epitopes / immunology
  • Female
  • Fluorescent Antibody Technique
  • Gene Expression
  • Humans
  • Membrane Proteins
  • Molecular Sequence Data
  • Ovarian Neoplasms / genetics*
  • Ovarian Neoplasms / metabolism
  • Radioimmunoprecipitation Assay
  • Transfection
  • Tumor Cells, Cultured


  • CA-125 Antigen
  • DNA, Complementary
  • Epitopes
  • MUC16 protein, human
  • Membrane Proteins