title: Single-stranded RNAs use RNAi to potently and allele-selectively inhibit mutant huntingtin expression.
abstract: Mutant huntingtin (HTT) protein causes Huntington disease (HD), an incurable neurological disorder. Silencing mutant HTT using nucleic acids would eliminate the root cause of HD. Developing nucleic acid drugs is challenging, and an ideal clinical approach to gene silencing would combine the simplicity of single-stranded antisense oligonucleotides with the efficiency of RNAi. Here, we describe RNAi by single-stranded siRNAs (ss-siRNAs). ss-siRNAs are potent (>100-fold more than unmodified RNA) and allele-selective (>30-fold) inhibitors of mutant HTT expression in cells derived from HD patients. Strategic placement of mismatched bases mimics micro-RNA recognition and optimizes discrimination between mutant and wild-type alleles. ss-siRNAs require Argonaute protein and function through the RNAi pathway. Intraventricular infusion of ss-siRNA produced selective silencing of the mutant HTT allele throughout the brain in a mouse HD model. These data demonstrate that chemically modified ss-siRNAs function through the RNAi pathway and provide allele-selective compounds for clinical development.
authors.affiliation: Departments of Pharmacology and Biochemistry, UT Southwestern Medical Center, 6001 Forest Park Road, Dallas, TX 75390-9041, USA.
authors.forename: Dongbo
authors.initials: D
authors.lastname: Yu
authors.forename: Hannah
authors.initials: H
authors.lastname: Pendergraff
authors.forename: Jing
authors.initials: J
authors.lastname: Liu
authors.forename: Holly B
authors.initials: HB
authors.lastname: Kordasiewicz
authors.forename: Don W
authors.initials: DW
authors.lastname: Cleveland
authors.forename: Eric E
authors.initials: EE
authors.lastname: Swayze
authors.forename: Walt F
authors.initials: WF
authors.lastname: Lima
authors.forename: Stanley T
authors.initials: ST
authors.lastname: Crooke
authors.forename: Thazha P
authors.initials: TP
authors.lastname: Prakash
authors.forename: David R
authors.initials: DR
authors.lastname: Corey
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism; D002460:Cell Line; D004195:Disease Models, Animal; D006801:Humans; D000071058:Huntingtin Protein; D006816:Huntington Disease / Q000235:genetics* / Q000628:therapy*; D051379:Mice; D009419:Nerve Tissue Proteins / Q000235:genetics*; D020319:Oligodeoxyribonucleotides, Antisense / Q000235:genetics; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism*
chemical_list: C086055:HTT protein, human; D000071058:Huntingtin Protein; D009419:Nerve Tissue Proteins; D020319:Oligodeoxyribonucleotides, Antisense; D034741:RNA, Small Interfering