Off-target genomic DNA sites with partial complementarity to the CSF1-targeting gRNA (CSF1 gRNA off-targets)

Off-target genomic DNA sites with partial complementarity to the CSF1-targeting gRNA are unintended sequences in the genome where the CRISPR-Cas9 system may induce double-strand breaks due to sequence homology with the intended CSF1 target (Fu et al., 2013, Nature Biotechnology). These sites are a major concern in gene editing because the Cas9 nuclease can tolerate several mismatches between the guide RNA (gRNA) and the DNA template, leading to non-specific cleavage (Zhang et al., 2015, Molecular Therapy - Nucleic Acids). In the context of CSF1 (Colony Stimulating Factor 1) targeting, which is often explored to modulate tumor-associated macrophages, off-target effects could lead to the disruption of tumor suppressor genes or the activation of oncogenes (Tsai et al., 2015, Nature Biotechnology). Such unintended modifications pose risks of genotoxicity and chromosomal translocations, which are critical safety hurdles for clinical translation. Advanced detection methods like GUIDE-seq and CIRCLE-seq are employed to map these sites and ensure the specificity of the therapeutic intervention (Tsai et al., 2015, Nature Biotechnology).

Other names

CRISPR off-target sitesNon-specific DNA cleavage sitesCSF1 gRNA off-targetsMismatched genomic sequences

Unintended binding and cleavage of DNA by the Cas9 nuclease guided by a gRNA with partial sequence homology to non-target genomic regions (Fu et al., 2013, Nature Biotechnology).