Asymmetric Shorter-duplex siRNA Structures Trigger Efficient Gene Silencing With Reduced Nonspecific Effects

• Published in: Molecular therapy Vol. 17; no. 4; pp. 725 - 732
• Main Authors: Chang, Chan Il, Yoo, Jae Wook, Hong, Sun Woo, Lee, Shi Eun, Kang, Hye Suk, Sun, Xiangao, Rogoff, Harry A, Ban, Changill, Kim, Soyoun, Li, Chiang J, Lee, Dong-ki
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.04.2009; Elsevier Limited; Nature Publishing Group
• Subjects: Base Sequence; Cell Line; Chemistry; Flow Cytometry; Gene Silencing; Gene therapy; Genomics; Humans; Insects; Materials science; Medical research; MicroRNAs; Original; Reverse Transcriptase Polymerase Chain Reaction; RNA, Small Interfering - chemistry; United States > US; Massachusetts
• ISSN: 1525-0016; 1525-0024
• DOI: 10.1038/mt.2008.298

Small interfering RNAs (siRNAs) are short, double-stranded RNAs that mediate efficient gene silencing in a sequence-specific manner by utilizing the endogenous RNA interference (RNAi) pathway. The current standard synthetic siRNA structure harbors a 19–base-pair duplex region with 3′ overhangs of 2 nucleotides (the so-called 19+2 form). However, the synthetic 19+2 siRNA structure exhibits several sequence-independent, nonspecific effects, which has posed challenges to the development of RNAi therapeutics and specific silencing of genes in research. In this study, we report on the identification of truncated siRNA backbone structures with duplex regions shorter than 19 bp (referred to as asymmetric shorter-duplex siRNAs or asiRNAs) that can efficiently trigger gene silencing in human cell lines. Importantly, this asiRNA structure significantly reduces nonspecific effects triggered by conventional 19+2 siRNA scaffold, such as sense-strand–mediated off-target gene silencing and saturation of the cellular RNAi machinery. Our results suggest that this asiRNA structure is an important alternative to conventional siRNAs for both functional genomics studies and therapeutic applications.