Allele-Selective Inhibition of Mutant Atrophin-1 Expression by Duplex and Single-Stranded RNAs

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• 作者：Jiaxin Hu ; Jing Liu ; K. Jayaprakash Narayanannair ; Jeremy G. Lackey ; Satya Kuchimanchi ; Kallanthottathil G. Rajeev ; Muthiah Manoharan ; Eric E. Swayze ; Walt F. Lima ; Thazha P. Prakash ; Qin Xiang ; Carlos Martinez ; David R. Corey
• 刊名：Biochemistry
• 出版年：2014
• 出版时间：July 22, 2014
• 年：2014
• 卷：53
• 期：28
• 页码：4510-4518
• 全文大小：685K
• ISSN：1520-4995

文摘

Dentatorubral-pallidoluysian atrophy (DRPLA) is a progressive neurodegenerative disorder that currently has no curative treatments. DRPLA is caused by an expansion of a CAG trinucleotide repeat region within the protein-encoding sequence of the atrophin-1 (ATN-1) gene. Inhibition of mutant ATN-1 protein expression is one strategy for treating DRPLA, and allele-selective gene silencing agents that block mutant expression over wild-type expression would be lead compounds for therapeutic development. Here we develop an assay for distinguishing mutant from wild-type ATN-1 protein by gel electrophoresis. We use this assay to evaluate duplex RNAs and single-stranded silencing RNAs (ss-siRNAs) for allele-selective inhibition of ATN-1 protein expression. We observed potent and allele-selective inhibition by RNA duplexes that contain mismatched bases relative to the CAG target and have the potential to form miRNA-like complexes. ss-siRNAs that contained mismatches were as selective as mismatch-containing duplexes. We also report allele-selective inhibition by duplex RNAs containing unlocked nucleic acids or abasic substitutions, although selectivities are not as high. Five compounds that showed >8-fold allele selectivity for mutant ATN-1 were also selective for inhibiting the expression of two other trinucleotide repeat disease genes, ataxin-3 (ATXN-3) and huntingtin (HTT). These data demonstrate that the expanded trinucleotide repeat within ATN-1 mRNA is a potential target for compounds designed to achieve allele-selective inhibition of ATN-1 protein, and one agent may allow the targeting of multiple disease genes.