AON-based degradation of c.151C>T mutant COCH transcripts associated with dominantly inherited hearing impairment DFNA9

Erik de Vrieze; Jorge Cañas Martín; Jolien Peijnenborg; Aniek Martens; Jaap Oostrik; Simone van den Heuvel; Kornelia Neveling; Ronald Pennings; Hannie Kremer; Erwin van Wijk

doi:10.1016/j.omtn.2021.02.033

AON-based degradation of c.151C>T mutant COCH transcripts associated with dominantly inherited hearing impairment DFNA9

Mol Ther Nucleic Acids. 2021 Mar 1:24:274-283. doi: 10.1016/j.omtn.2021.02.033. eCollection 2021 Jun 4.

Authors

Erik de Vrieze^{1

2}, Jorge Cañas Martín¹, Jolien Peijnenborg¹, Aniek Martens¹, Jaap Oostrik^{1

2}, Simone van den Heuvel³, Kornelia Neveling^{3

4}, Ronald Pennings^{1

2}, Hannie Kremer^{1

2

3}, Erwin van Wijk^{1

2}

Affiliations

¹ Department of Otorhinolaryngology, Radboud University Medical Center, 6525 GA Nijmegen, the Netherlands.
² Donders Institute for Brain, Cognition, and Behaviour, Radboud University Medical Center, 6525 GA Nijmegen, the Netherlands.
³ Department of Human Genetics, Radboud University Medical Center, 6525 GA Nijmegen, the Netherlands.
⁴ Radboud Institute for Health Sciences, Radboud University Medical Center, 6525 GA Nijmegen, the Netherlands.

Abstract

The c.151C>T founder mutation in COCH is a frequent cause of late-onset, dominantly inherited hearing impairment and vestibular dysfunction (DFNA9) in the Dutch/Belgian population. The initial clinical symptoms only manifest between the 3rd and 5th decade of life, which leaves ample time for therapeutic intervention. The dominant inheritance pattern and established non-haploinsufficiency disease mechanism indicate that suppressing translation of mutant COCH transcripts has high therapeutic potential. Single-molecule real-time (SMRT) sequencing resulted in the identification of 11 variants with a low population frequency (<10%) that are specific to the c.151C>T mutant COCH allele. Proof of concept was obtained that gapmer antisense oligonucleotides (AONs), directed against the c.151C>T mutation or mutant allele-specific intronic variants, are able to induce mutant COCH transcript degradation when delivered to transgenic cells expressing COCH minigenes. The most potent AON, directed against the c.151C>T mutation, was able to induce a 60% decrease in mutant COCH transcripts without affecting wild-type COCH transcript levels. Allele specificity decreased when increasing concentrations of AON were delivered to the cells. With the proven safety of AONs in humans, and rapid advancements in inner ear drug delivery, our in vitro studies indicate that AONs offer a promising treatment modality for DFNA9.

Keywords: COCH; DFNA9; RNase H1; antisense oligonucleotides; deafness; gapmer; genetic therapy; hearing loss.