Rescue of polyglutamine-mediated cytotoxicity by double-stranded RNA-mediated RNA interference

Hum Mol Genet. 2002 Jan 15;11(2):175-84. doi: 10.1093/hmg/11.2.175.


RNA interference (RNAi) is a mechanism that appears to control unwanted gene expression in a wide range of species. In Drosophila, RNAi is most effectively induced by double-stranded RNAs (dsRNAs) of over approximately 80 nucleotides (nt) and in mammalian cells an RNAi-like inhibition of gene expression has been shown to be mediated by dsRNAs of approximately 21-23 nt. To test if RNAi can be used to specifically down-regulate a human disease-related transcript we have used Drosophila and human tissue culture models of the dominant genetic disorder spinobulbar muscular atrophy (SBMA). A variety of different dsRNAs were assessed for the ability to inhibit expression of transcripts that included a truncated human androgen receptor (ar) gene containing different CAG repeat lengths (16-112 repeats). In Drosophila cells, dsRNAs corresponding to non-repetitive sequences mediated a high degree of sequence-specific inhibition, whereas RNA duplexes containing CAG repeat tracts only induced gene-specific inhibition when flanking ar sequences were included; dsRNAs containing various lengths of CAG repeats plus ar sequences were unable to induce allele-specific interference. In mammalian cells we tested sequence-specific small dsRNAs of 22 nt; these rescued the toxicity and caspase-3 activation induced by plasmids expressing a transcript encoding an expanded polyglutamine tract. This study demonstrates the feasibility of targeting a transcript associated with an important group of genetic diseases by RNAi.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Apoptosis
  • Caspase 3
  • Caspases / metabolism
  • Cell Line
  • Disease Models, Animal
  • Down-Regulation*
  • Drosophila
  • Feasibility Studies
  • Gene Silencing
  • Genetic Therapy
  • Green Fluorescent Proteins
  • Humans
  • Luminescent Proteins / metabolism
  • Muscular Disorders, Atrophic / genetics*
  • Peptides / genetics*
  • Peptides / toxicity
  • RNA / metabolism
  • RNA, Double-Stranded / metabolism*
  • Receptors, Androgen / genetics
  • Recombinant Fusion Proteins / genetics
  • Trinucleotide Repeats


  • Luminescent Proteins
  • Peptides
  • RNA, Double-Stranded
  • Receptors, Androgen
  • Recombinant Fusion Proteins
  • Green Fluorescent Proteins
  • polyglutamine
  • RNA
  • CASP3 protein, human
  • Caspase 3
  • Caspases