DNA polymerase beta expression differences in selected human tumors and cell lines

Carcinogenesis. 1999 Jun;20(6):1049-54. doi: 10.1093/carcin/20.6.1049.


A long-standing question in cancer biology has been the extent to which DNA repair may be altered during the process of carcinogenesis. We have shown recently that DNA polymerase beta (beta-pol) provides a rate-determining function during in vitro repair of abasic sites by one of the mammalian DNA base excision repair pathways. Therefore, altered expression of beta-pol during carcinogenesis could alter base excision repair and, consequently, be critical to the integrity of the mammalian genome. We examined the expression of beta-pol in several cell lines and human adenocarcinomas using a quantitative immunoblotting method. In cell lines from normal breast or colon, the level of beta-pol was approximately 1 ng/mg cell extract, whereas in all of the breast and colon adenocarcinoma cell lines tested, a higher level of beta-pol was observed. In tissue samples, colon adenocarcinomas had a higher level of beta-pol than adjacent normal mucosa. Breast adenocarcinomas exhibited a wide range of beta-pol expression: one tumor had a much higher level of beta-pol (286 ng/mg cell extract) than adjacent normal breast tissue, whereas another tumor had the same level of beta-pol as adjacent normal tissue. Differences in beta-pol expression level, from normal to elevated, were also observed with prostate adenocarcinomas. All kidney adenocarcinomas tested had a slightly lower beta-pol level than adjacent normal tissue. This study reveals that the base excision repair enzyme DNA polymerase beta is up-regulated in some types of adenocarcinomas and cell lines, but not in others.

MeSH terms

  • Adenocarcinoma / enzymology
  • Amino Acid Sequence
  • Animals
  • Antibodies, Monoclonal / immunology
  • Blotting, Western
  • Breast Neoplasms / enzymology
  • CHO Cells
  • Cell Line
  • Colonic Neoplasms / enzymology
  • Cricetinae
  • DNA Polymerase beta / chemistry
  • DNA Polymerase beta / immunology
  • DNA Polymerase beta / metabolism*
  • Epitopes / chemistry
  • Female
  • Humans
  • Middle Aged
  • Molecular Sequence Data
  • Tumor Cells, Cultured


  • Antibodies, Monoclonal
  • Epitopes
  • DNA Polymerase beta