Precise base editing without unintended indels in human cells and mouse primary myoblasts

Area of Science:

• Molecular Biology
• Genome Editing
• Biotechnology

Background:

• Base editors enable precise single-nucleotide genomic changes but often cause unintended insertions/deletions (indels).
• These indels limit the clinical applicability of current base editing technologies.

Purpose of the Study:

• To develop a base editing strategy that eliminates unwanted indels at target sites.
• To enhance nucleotide conversion efficiency and reduce off-target mutations.

Main Methods:

• Utilized dead Cas9 (dCas9) instead of nickase Cas9 (nCas9) in base editors.
• Incorporated chromatin-modulating peptides to improve editing efficiency.
• Tested the modified base editors in human cell lines and mouse primary myoblasts.

Main Results:

• The dCas9-based base editors with chromatin-modulating peptides achieved efficient nucleotide substitutions without indels.
• The modified system demonstrated improved efficiency compared to conventional base editors.
• Reduced DNA-level off-target effects were observed with the proposed approach.

Conclusions:

• The developed base editing strategy offers a promising method for accurate and safe genome editing.
• This approach holds potential for advancing clinical applications of base editing technology.