Long-term in vivo CRISPR/Cas9 gene editing in liver triggers host immunity and clonal mutations in DNA Repair Genes

Our study reveals that sustained in vivo genome editing in mouse model establishes a chronic inflammatory microenvironment and elevates the risk of genomic instability in the liver. Although in vitro studies have suggested that Cas9 editing can select for tumor-prone clones in repaidly proliferating cell lines, whether similar selective pressures operate in vivo has remained unclear. Our transcriptomic analyses indicate that long-term editing suppresses apoptotic pathways in the liver, independent of on-target gene modulation. Whole-exome sequencing further revealed enrichment of nonsynonymous mutations in DNA repair and damage response genes, albeit at low overall frequency. We also detected elevated rates of chromosomal translocations between the target site and other genomic regions in highly edited individuals.