Loss of mismatch repair activity in simian virus 40 large T antigen-immortalized BPH-1 human prostatic epithelial cell line

Mol Carcinog. 2001 Jul;31(3):145-51. doi: 10.1002/mc.1049.

Abstract

Simian virus 40 large T antigen (SVLTAg) has been used to immortalize cells; however, the mechanism leading to immortalization is still unclear. We hypothesize that DNA mismatch repair (MMR) activity is important during SVLTAg-induced immortalization. To test this hypothesis, we used the SVLTAg-immortalized cell line BPH-1 derived from human benign prostate epithelial cells to analyze MMR activity and the expression of MMR genes (hMLH1, hPMS1, hPMS2, hMSH2, hMSH3, and hMSH6). The results demonstrated that BPH-1 cells were deficient in repairing G:T, A:C, and G:G mispairs in bacteriophage M13mp2. Reverse-transcription polymerase chain reaction experiments indicated MMR genes (hMSH3, hMSH6, and hPMS1) were expressed at a low level in BPH-1 cells. In contrast, all six MMR genes were expressed in human benign prostate hyperplasia tissues. Downregulation of hMSH3, hMSH6, and hPMS1 genes is not a result of the hypermethylation mechanism because demethylation with 5-aza-2'-deoxycytidine did not restore expression of these genes. Although the hMLH1 gene is expressed in BPH-1 cells, western blotting and exon analyses demonstrated that hMLH1 was mutated and/or deleted in BPH-1 cells.

Publication types

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

MeSH terms

  • Adaptor Proteins, Signal Transducing
  • Adenosine Triphosphatases*
  • Antigens, Polyomavirus Transforming / metabolism*
  • Azacitidine / analogs & derivatives
  • Azacitidine / pharmacology
  • Base Pair Mismatch*
  • Blotting, Western
  • Carrier Proteins / biosynthesis
  • Cell Line
  • DNA Methylation
  • DNA Repair Enzymes*
  • DNA Repair*
  • DNA-Binding Proteins / biosynthesis
  • Decitabine
  • Down-Regulation
  • Epithelial Cells / cytology*
  • Exons
  • Fungal Proteins / biosynthesis
  • Gene Deletion
  • Humans
  • Male
  • Mismatch Repair Endonuclease PMS2
  • Models, Biological
  • Multidrug Resistance-Associated Proteins*
  • MutL Protein Homolog 1
  • MutL Proteins
  • MutS Homolog 2 Protein
  • MutS Homolog 3 Protein
  • Mutation
  • Neoplasm Proteins / biosynthesis
  • Nuclear Proteins
  • Nucleic Acid Heteroduplexes
  • Prostate / cytology*
  • Proto-Oncogene Proteins / biosynthesis
  • Reverse Transcriptase Polymerase Chain Reaction
  • Saccharomyces cerevisiae Proteins*

Substances

  • Adaptor Proteins, Signal Transducing
  • Antigens, Polyomavirus Transforming
  • Carrier Proteins
  • DNA-Binding Proteins
  • Fungal Proteins
  • MLH1 protein, human
  • MSH3 protein, human
  • MSH6 protein, S cerevisiae
  • Multidrug Resistance-Associated Proteins
  • MutS Homolog 3 Protein
  • Neoplasm Proteins
  • Nuclear Proteins
  • Nucleic Acid Heteroduplexes
  • PMS1 protein, human
  • Proto-Oncogene Proteins
  • Saccharomyces cerevisiae Proteins
  • Decitabine
  • Adenosine Triphosphatases
  • PMS2 protein, human
  • MSH2 protein, human
  • Mismatch Repair Endonuclease PMS2
  • MutL Protein Homolog 1
  • MutL Proteins
  • MutS Homolog 2 Protein
  • DNA Repair Enzymes
  • Azacitidine
  • multidrug resistance-associated protein 1