2. Academic Validation
  3. Combining nonsense mutation suppression therapy with nonsense-mediated decay inhibition in neurofibromatosis type 1

Combining nonsense mutation suppression therapy with nonsense-mediated decay inhibition in neurofibromatosis type 1

  • Mol Ther Nucleic Acids. 2023 Jun 26:33:227-239. doi: 10.1016/j.omtn.2023.06.018.
Sara H Osum 1,  Eunice I Oribamise 1,  Stanislas M A S Corbière 2,  Mandy Taisto 2,  Tyler Jubenville 1,  Alex Coutts 2,  Mark N Kirstein 1 3,  James Fisher 3,  Christopher Moertel 1,  Ming Du 4,  David Bedwell 4,  David A Largaespada 1,  Adrienne L Watson 2
Affiliations

Affiliations

  • 1 Masonic Cancer Center, Department of Pediatrics, University of Minnesota, 2-191 Moos Tower, 515 Delaware Street SE, Minneapolis, MN 55455, USA.
  • 2 Recombinetics Inc., 3388 Mike Collins Drive, #1, Eagan, MN 55121, USA.
  • 3 Department of Experimental and Clinical Pharmacology, College of Pharmacy, University of Minnesota, Room 459, 717 Delaware Street SE, Minneapolis, MN 55414, USA.
  • 4 Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Bevill Biomedical Research Building Room 432A, 845 19 Street South, Birmingham, AL 35294, USA.
PMID: 37520682 DOI: 10.1016/j.omtn.2023.06.018
Abstract

Neurofibromatosis type 1 (NF1) results from germline mutations in the tumor-suppressor gene NF1 and predisposes patients to developing nervous system tumors. Twenty percent of NF1 patients harbor nonsense mutations resulting in premature termination codons (PTCs). Nonsense suppression therapies can facilitate ribosomal readthrough of PTCs to restore full-length protein, but their potential in NF1 is underexplored. We developed a minipig model of NF1 carrying a PTC to test whether nonsense suppression could restore expression of the NF1-encoded protein neurofibromin in vitro and in vivo. Nonsense suppression did not reliably increase neurofibromin in primary NF1-/- Schwann cells isolated from minipig neurofibromas but could reduce phosphorylated ERK. Gentamicin in vivo produced a similar plasma pharmacokinetic profile to humans and was detectable in clinically relevant tissues, including cerebral cortex, sciatic nerve, optic nerve, and skin. In gentamicin-treated Animals, increased neurofibromin expression was seen in the optic nerve. Nonsense-mediated decay (NMD) causes degradation of transcripts with PTCs, which could impede nonsense suppression therapies. Nonsense suppression in combination with NMD inhibition restored neurofibromin protein expression in primary NF1-/- Schwann cells isolated from minipig neurofibromas. Thus, the effectiveness of nonsense suppression therapies can be improved in NF1 by the concurrent use of NMD inhibitors.

Keywords

MT: Delivery Strategies; minipig; neurofibromatosis; nonsense mutations; nonsense suppression; pharmacokinetics; preclinical models.

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