Toward therapy for DYT1 dystonia: allele-specific silencing of mutant TorsinA.
A three-nucleotide (GAG) deletion in the TOR1A gene is the most common cause of inherited dystonia, DYT1. Because the mutant protein, TorsinA (TA), is thought to act in a dominant manner to cause disease, inhibiting expression from the mutant gene represents a potentially powerful therapeutic strategy. In an effort to develop therapy for this disease, we tested whether small interfering RNA (siRNA) could selectively silence expression of mutant TA. Exploiting the three-base pair difference between wild-type and mutant alleles, we designed siRNAs to silence expression of mutant, wild-type, or both forms of TA. In transfected cells, siRNA successfully suppressed wild-type or mutant TA in an allele-specific manner: for example, mutant-specific siRNA reduced the levels of mutant TA to less than 1% of controls with minimal effect on wild-type TA expression. In cells expressing both alleles, thus simulating the heterozygous state, siRNA-mediated suppression remained robust and allele specific. Our siRNA studies demonstrate allele-specific targeting of a dominant neurogenetic disease gene and suggest the broad therapeutic potential of siRNA for DYT1 dystonia and other dominantly inherited neurological diseases.
Gonzalez-Alegre
Pedro
P
Department of Neurology, University of Iowa College of Medicine, Iowa City, IA 52242, USA.
Miller
Victor M
VM
Davidson
Beverly L
BL
Paulson
Henry L
HL
D000483:Alleles; D015153:Blotting, Western; D002352:Carrier Proteins / Q000235:genetics*; D018929:Cell Culture Techniques; D004421:Dystonia / Q000235:genetics* / Q000628:therapy*; D017353:Gene Deletion; D020868:Gene Silencing; D015316:Genetic Therapy / Q000379:methods*; D006801:Humans; D008856:Microscopy, Fluorescence; D018832:Molecular Chaperones; D010957:Plasmids / Q000235:genetics; D017354:Point Mutation / Q000235:genetics*; D034741:RNA, Small Interfering / Q000235:genetics*; D014162:Transfection / Q000379:methods
D002352:Carrier Proteins; D018832:Molecular Chaperones; D034741:RNA, Small Interfering; C108175:TOR1A protein, human