RNA Editing-Mediated Correction of TP53 Nonsense Mutations via Lipid Nanoparticle-Delivered Circular ADAR-Recruiting RNAs

Nonsense mutations account for over 20% of disease-associated
mutations,
which refer to the occurrence of premature termination codons (PTCs)
in gene sequences, resulting in truncated and dysfunctional proteins.
Nonetheless, due to poor accessibility of precise target sites and
the limitations of gene editing tools, there is still a lack of safe,
effective, and site-specific approach for correction of nonsense mutations.
Here, we designed a circular ADAR-recruiting RNA (Circ-arRNA) for
the in vivo RNA editing-mediated repair of the TP53-W53X nonsense mutation. Compared with linear arRNA, Circ-RNA demonstrates
strong intracellular stability and high efficiency for site-specific
correction of the TP53-W53X nonsense mutant, with
no detectable off-target effects on bystander bases. In triple-negative
breast cancer TP53-W53X 4T1 cells and tumor-bearing
mouse models, we used lipid nanoparticles (LNPs) to encapsulate and
deliver Circ-arRNA, which achieved mutation correction efficiencies
of 73.32 and 48.48%, respectively. Furthermore, Circ-arRNA LNPs effectively
restored full-length p53 protein expression and its functional activity,
significantly enhancing the sensitivity of tumor-bearing mice to paclitaxel
chemotherapy. Our research demonstrated the safety and efficacy of
LNP-based circular arRNA for specifically the repair of nonsense mutations
in vivo, highlighting the immense potential of ADAR-mediated editing
for correcting such mutations.