title: Allele-selective inhibition of mutant atrophin-1 expression by duplex and single-stranded RNAs.
abstract: 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.
authors: Departments of Pharmacology and Biochemistry, University of Texas Southwestern Medical Center , 6001 Forest Park Road, Dallas, Texas 75390-9041, United States.
authors: Jiaxin
authors: J
authors: Hu
authors: Jing
authors: J
authors: Liu
authors: K Jayaprakash
authors: KJ
authors: Narayanannair
authors: Jeremy G
authors: JG
authors: Lackey
authors: Satya
authors: S
authors: Kuchimanchi
authors: Kallanthottathil G
authors: KG
authors: Rajeev
authors: Muthiah
authors: M
authors: Manoharan
authors: Eric E
authors: EE
authors: Swayze
authors: Walt F
authors: WF
authors: Lima
authors: Thazha P
authors: TP
authors: Prakash
authors: Qin
authors: Q
authors: Xiang
authors: Carlos
authors: C
authors: Martinez
authors: David R
authors: DR
authors: Corey
mesh_terms: D000483:Alleles; D000067699:Ataxin-3; D002460:Cell Line; D005786:Gene Expression Regulation; D006801:Humans; D000071058:Huntingtin Protein; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism; D016254:Mutagenesis, Insertional; D020191:Myoclonic Epilepsies, Progressive / Q000188:drug therapy / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D009419:Nerve Tissue Proteins / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D009687:Nuclear Proteins / Q000096:biosynthesis / Q000235:genetics; D012330:RNA, Double-Stranded / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012097:Repressor Proteins / Q000096:biosynthesis / Q000235:genetics; D019680:Trinucleotide Repeat Expansion
chemical_list: C086055:HTT protein, human; D000071058:Huntingtin Protein; D035683:MicroRNAs; D009419:Nerve Tissue Proteins; D009687:Nuclear Proteins; D012330:RNA, Double-Stranded; D012333:RNA, Messenger; D012097:Repressor Proteins; C095278:atrophin-1; C092341:ATXN3 protein, human; D000067699:Ataxin-3