Potent and Selective Antisense Oligonucleotides Targeting Single-Nucleotide Polymorphisms in the Huntington Disease Gene / Allele-Specific Silencing of Mutant Huntingtin

• Published in: Molecular therapy Vol. 19; no. 12; pp. 2178 - 2185
• Main Authors: Carroll, Jeffrey B, Warby, Simon C, Southwell, Amber L, Doty, Crystal N, Greenlee, Sarah, Skotte, Niels, Hung, Gene, Bennett, C Frank, Freier, Susan M, Hayden, Michael R
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.12.2011; Elsevier Limited; Nature Publishing Group
• Subjects: Alleles; Animals; Apoptosis; Brain - metabolism; Brain - pathology; Cells, Cultured; Chromosomes; Cytomegalovirus; Disease; Female; Fibroblasts - cytology; Fibroblasts - metabolism; Gene Silencing; Genetic Therapy; Humans; Huntingtin Protein; Huntington Disease - genetics; Huntington Disease - therapy; Male; Medicine; Mice; Mice, Transgenic; Mutant Proteins - genetics; Mutation; Nerve Tissue Proteins - genetics; Neurodegeneration; Neurons - metabolism; Neurons - pathology; Nuclear Proteins - genetics; Oligonucleotides, Antisense - therapeutic use; Original; Pedigree; Polymorphism; Polymorphism, Single Nucleotide - genetics; Proteins; Research centers; RNA, Messenger - genetics; Serotonin Plasma Membrane Transport Proteins - chemistry; Serotonin Plasma Membrane Transport Proteins - genetics; Serotonin Plasma Membrane Transport Proteins - metabolism; Trinucleotide Repeat Expansion - genetics; Canada; California; Vancouver British Columbia Canada; United States > US
• ISSN: 1525-0016; 1525-0024
• DOI: 10.1038/mt.2011.201

Huntington disease (HD) is an autosomal dominant neurodegenerative disorder caused by CAG-expansion in the huntingtin gene (HTT) that results in a toxic gain of function in the mutant huntingtin protein (mHTT). Reducing the expression of mHTT is therefore an attractive therapy for HD. However, wild-type HTT protein is essential for development and has critical roles in maintaining neuronal health. Therapies for HD that reduce wild-type HTT may therefore generate unintended negative consequences. We have identified single-nucleotide polymorphism (SNP) targets in the human HD population for the disease-specific targeting of the HTT gene. Using primary cells from patients with HD and the transgenic YAC18 and BACHD mouse lines, we developed antisense oligonucleotide (ASO) molecules that potently and selectively silence mHTT at both exonic and intronic SNP sites. Modification of these ASOs with S-constrained-ethyl (cET) motifs significantly improves potency while maintaining allele selectively in vitro. The developed ASO is potent and selective for mHTT in vivo after delivery to the mouse brain. We demonstrate that potent and selective allele-specific knockdown of the mHTT protein can be achieved at therapeutically relevant SNP sites using ASOs in vitro and in vivo.