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A Standard Methodology to Examine On-site Mutagenicity As a Function of Point Mutation Repair Catalyzed by CRISPR/Cas9 and SsODN in Human Cells
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A Standard Methodology to Examine On-site Mutagenicity As a Function of Point Mutation Repair Catalyzed by CRISPR/Cas9 and SsODN in Human Cells

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Implications of cell cycle progression on functional sequence correction by short single-stranded DNA

P A Olsen1, M Randol, S Krauss

  • 1Department for Cellular and Genetic Therapy, Institute for Microbiology, Rikshospitalet, Forskningsparken, Oslo, Norway.

Gene Therapy
|January 28, 2005
PubMed

Insights

Targeted gene correction using single-stranded oligonucleotides (ssODN) in cells shows promise for gene therapy. This method achieves high correction rates, influenced by cell cycle, but requires further optimization for viable colony formation.

Area of Science:

  • Molecular Biology
  • Gene Therapy
  • Cell Biology

Background:

  • Oligonucleotide-based sequence alteration in cells presents significant challenges for gene therapy.
  • Developing efficient and reproducible methods for targeted genomic modification is crucial.

Purpose of the Study:

  • To investigate the efficacy of single-stranded oligonucleotides (ssODN) for targeted sequence correction in mammalian cells.
  • To explore the influence of cell cycle phase on the efficiency of ssODN-mediated gene correction.
  • To assess the viability and cell cycle behavior of cells following targeted sequence alteration.

Main Methods:

  • Utilized Chinese Hamster Ovary (CHO) cell lines with integrated EGFP reporter genes.
  • Transfected cells with corrective single-stranded oligonucleotides (ssODN).
  • Analyzed cell cycle progression and targeted sequence correction rates using flow cytometry and genomic analysis.

Main Results:

  • Achieved reproducible targeted sequence correction rates of approximately 4.5% in CHO cells using ssODN.
  • Demonstrated that early S phase is optimal for ssODN-mediated sequence correction.
  • Observed that corrected cells predominantly arrest in G2/M phase, with a small percentage forming viable colonies.
  • Showed that G2/M arrest can be partially alleviated by specific chemical treatments.

Conclusions:

  • Single-stranded oligonucleotides (ssODN) offer a promising approach for high-efficiency targeted gene alteration.
  • Cell cycle synchronization can potentially enhance the efficiency of ssODN-mediated gene editing.
  • Further research is needed to overcome cell cycle arrest and improve the generation of viable, genetically modified cell populations for therapeutic applications.

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