Synthetic dsRNA Dicer substrates enhance RNAi potency and efficacy

• Published in: Nature biotechnology 2005-02, Vol.23 (2), p.222-226
• Main Authors: Kim, Dong-Ho, Behlke, Mark A, Rose, Scott D, Chang, Mi-Sook, Choi, Sangdun, Rossi, John J
• Format: Article
• Language: English
• Subjects: Agriculture; Bioinformatics; Biological and medical sciences; Biomedical and Life Sciences; Biomedical Engineering/Biotechnology; Biomedicine; Biotechnology; Fundamental and applied biological sciences. Psychology; Gene Expression Regulation - genetics; Gene Silencing - physiology; Gene Targeting - methods; Genetic Engineering - methods; Health. Pharmaceutical industry; Industrial applications and implications. Economical aspects; letter; Life Sciences; Miscellaneous; Ribonuclease III - chemistry; Ribonuclease III - metabolism; RNA, Small Interfering - chemistry; RNA, Small Interfering - genetics; Substrates; Transfection - methods
• ISSN: 1087-0156; 1546-1696
• DOI: 10.1038/nbt1051

RNA interference (RNAi) is the process of sequence-specific post-transcriptional gene silencing triggered by double-stranded RNAs 1 , 2 , 3 . In attempts to identify RNAi triggers that effectively function at lower concentrations, we found that synthetic RNA duplexes 25–30 nucleotides in length can be up to 100-fold more potent than corresponding conventional 21-mer small interfering RNAs (siRNAs). Some sites that are refractory to silencing by 21-mer siRNAs can be effectively targeted by 27-mer duplexes, with silencing lasting up to 10 d. Notably, the 27-mers do not induce interferon or activate protein kinase R (PKR). The enhanced potency of the longer duplexes is attributed to the fact that they are substrates of the Dicer endonuclease, directly linking the production of siRNAs to incorporation in the RNA-induced silencing complex. These results provide an alternative strategy for eliciting RNAi-mediated target cleavage using low concentrations of synthetic RNA as substrates for cellular Dicer-mediated cleavage.