Allele-Selective Inhibition of Mutant Huntingtin Expression with Antisense Oligonucleotides Targeting the Expanded CAG Repeat

• Published in: Biochemistry (Easton) Vol. 49; no. 47; pp. 10166 - 10178
• Main Authors: Gagnon, Keith T, Pendergraff, Hannah M, Deleavey, Glen F, Swayze, Eric E, Potier, Pierre, Randolph, John, Roesch, Eric B, Chattopadhyaya, Jyoti, Damha, Masad J, Bennett, C. Frank, Montaillier, Christophe, Lemaitre, Marc, Corey, David R
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 30.11.2010
• Subjects: Alleles; Biochemistry; Biokemi; Cell Line; Chemistry; Gene Expression - drug effects; Humans; Huntingtin Protein; Huntington Disease - drug therapy; Huntington Disease - genetics; Kemi; NATURAL SCIENCES; NATURVETENSKAP; Nerve Tissue Proteins - biosynthesis; Nerve Tissue Proteins - genetics; Nuclear Proteins - biosynthesis; Nuclear Proteins - genetics; Oligonucleotides - genetics; Oligonucleotides - pharmacology; Oligonucleotides, Antisense - genetics; Oligonucleotides, Antisense - pharmacology; Oligonucleotides, Antisense - therapeutic use; Phosphorothioate Oligonucleotides - pharmacology; Ribonuclease H - metabolism; Structure-Activity Relationship; Trinucleotide Repeat Expansion - drug effects
• ISSN: 0006-2960; 1520-4995; 1520-4995
• DOI: 10.1021/bi101208k

Huntington’s disease (HD) is a currently incurable neurodegenerative disease caused by the expansion of a CAG trinucleotide repeat within the huntingtin (HTT) gene. Therapeutic approaches include selectively inhibiting the expression of the mutated HTT allele while conserving function of the normal allele. We have evaluated a series of antisense oligonucleotides (ASOs) targeted to the expanded CAG repeat within HTT mRNA for their ability to selectively inhibit expression of mutant HTT protein. Several ASOs incorporating a variety of modifications, including bridged nucleic acids and phosphorothioate internucleotide linkages, exhibited allele-selective silencing in patient-derived fibroblasts. Allele-selective ASOs did not affect the expression of other CAG repeat-containing genes and selectivity was observed in cell lines containing minimal CAG repeat lengths representative of most HD patients. Allele-selective ASOs left HTT mRNA intact and did not support ribonuclease H activity in vitro. We observed cooperative binding of multiple ASO molecules to CAG repeat-containing HTT mRNA transcripts in vitro. These results are consistent with a mechanism involving inhibition at the level of translation. ASOs targeted to the CAG repeat of HTT provide a starting point for the development of oligonucleotide-based therapeutics that can inhibit gene expression with allelic discrimination in patients with HD.