Recruiting Endogenous ADARs with Antisense Oligonucleotides to Reprogram the Transcriptome

Huge efforts are made to engineer safe and efficient genome editing tools. An alternative might be the harnessing of ADAR-mediated RNA editing. We now present the engineering of chemically optimized antisense oligonucleotides that recruit endogenous human ADARs to edit endogenous transcripts in a simple and programmable way, an approach we refer to as RESTORE. Notably, RESTORE was markedly precise, and there was no evidence for perturbation of the natural editing homeostasis. We applied RESTORE to a panel of standard human cell lines, but also to several human primary cells including hepatocytes. In contrast to other RNA and DNA editing strategies, this approach requires only the administration of an oligonucleotide, circumvents the ectopic expression of proteins, and thus represents an attractive platform for drug development. In this respect we have shown the repair of the PiZZ mutation causing α1-antitrypsin deficiency and the editing of phosphotyrosine 701 in STAT1. Identification of off-target editing events and Interferon-a influence in HeLa cell line transfected with an ASO for RNA editing by RNA-Seq, 2 samples (ASO +/- IFN) , 2 control sample (+/-IFN), 2 biologically independent experiments for each sample, 8 samples in total