CRISPR-Cas9 gene editing induced complex on-target outcomes in human cells

Area of Science:

• Genomics
• Molecular Biology
• Biotechnology

Background:

• CRISPR-Cas9 is a revolutionary genome editing technology with significant therapeutic potential.
• Concerns regarding CRISPR-Cas9 primarily focused on off-target mutations.
• Emerging evidence indicates complex on-target alterations following DNA repair.

Purpose of the Study:

• To review CRISPR-Cas9-induced on-target deleterious outcomes.
• To discuss potential safety concerns for clinical gene editing.
• To explore strategies for achieving safe gene therapy.

Main Methods:

• Literature review of studies reporting CRISPR-Cas9 on-target effects.
• Analysis of complex on-target mutations beyond small indels.
• Synthesis of findings on gene rearrangement and loss of heterozygosity.

Main Results:

• CRISPR-Cas9 can induce unintended on-target mutations, including large deletions and gene rearrangements.
• Loss of heterozygosity has been observed as a consequence of on-target double-strand break repair.
• These complex on-target effects pose safety risks for gene therapy.

Conclusions:

• On-target mutations are a significant safety consideration for CRISPR-Cas9 gene therapy.
• Understanding and mitigating these unintended outcomes is crucial for clinical translation.
• Further research is needed to develop safer gene editing strategies.