Chromosomal mutations induced by triplex-forming oligonucleotides in mammalian cells

Nucleic Acids Res. 1999 Feb 15;27(4):1176-81. doi: 10.1093/nar/27.4.1176.

Abstract

Specific recognition of a region of duplex DNA by triplex-forming oligonucleotides (TFOs) provides an attractive strategy for genetic manipulation. Based on this, we have investigated the ability of the triplex-directed approach to induce mutations at a chromosomal locus in living cells. A mouse fibroblast cell line was constructed containing multiple chromosomal copies of the lambdasupFG1 vector carrying the supFG1 mutation-reporter gene. Cells were treated with specific (psoAG30) or control (psoSCR30) psoralen-conjugated TFOs in the presence and absence of UVA irradiation. The results demonstrated a 6- to 10-fold induction of supFG1 mutations in the psoAG30-treated cells as compared with psoSCR30-treated or untreated control cells. Interestingly, UVA irradiation had no effect onthe mutation frequencies induced by the psoralen-conjugated TFOs, suggesting a triplex-mediated but photoproduct-independent process of mutagenesis. Sequencing data were consistent with this finding since the expected T.A-->A.T transversions at the predicted psoralen crosslinking site were not detected. However, insertions and deletions were detected within the triplex binding site, indicating a TFO-specific induction of mutagenesis. This result demonstrates the ability of triplex-forming oligonucleotides to influence mutation frequencies at a specific site in a mammalian chromosome.

Publication types

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

MeSH terms

  • Animals
  • Base Sequence
  • Cell Line
  • Chromosomes
  • DNA*
  • Furocoumarins
  • Genetic Vectors
  • Mammals
  • Mice
  • Molecular Sequence Data
  • Mutagenesis*
  • Nucleic Acid Conformation
  • Oligodeoxyribonucleotides*
  • Research Design

Substances

  • Furocoumarins
  • Oligodeoxyribonucleotides
  • triplex DNA
  • DNA