title: Dual-target gene silencing by using long, synthetic siRNA duplexes without triggering antiviral responses.
abstract: Chemically synthesized small interfering RNAs (siRNAs) can specifically knock-down expression of target genes via RNA interference (RNAi) pathway. To date, the length of synthetic siRNA duplex has been strictly maintained less than 30 bp, because an early study suggested that double-stranded RNAs (dsRNAs) longer than 30 bp could not trigger specific gene silencing due to the induction of nonspecific antiviral interferon responses. Contrary to the current belief, here we show that synthetic dsRNA as long as 38 bp can result in specific target gene silencing without nonspecific antiviral responses. Using this longer duplex structure, we have generated dsRNAs, which can simultaneously knock-down expression of two target genes (termed as dual-target siRNAs or dsiRNAs). Our results thus demonstrate the structural flexibility of gene silencing siRNAs, and provide a starting point to construct multifunctional RNA structures. The dsiRNAs could be utilized to develop a novel therapeutic gene silencing strategy against diseases with multiple gene alternations such as viral infection and cancer.
authors.affiliation: Global Research Laboratory for RNAi Medicine, Department of Chemistry and Brain Korea 21 School of Chemical Materials Science, Sungkyunkwan University, Suwon 440-746, Korea.
authors.forename: Chan Il
authors.initials: CI
authors.lastname: Chang
authors.forename: Hye Suk
authors.initials: HS
authors.lastname: Kang
authors.forename: Changill
authors.initials: C
authors.lastname: Ban
authors.forename: Soyoun
authors.initials: S
authors.lastname: Kim
authors.forename: Dong-Ki
authors.initials: DK
authors.lastname: Lee
mesh_terms: D020029:Base Pairing / Q000235:genetics; D001483:Base Sequence; D020868:Gene Silencing; D006367:HeLa Cells; D006801:Humans; D007113:Immunity, Innate / Q000276:immunology; D008969:Molecular Sequence Data; D009692:Nucleic Acid Heteroduplexes / Q000235:genetics*; D034622:RNA Interference; D012330:RNA, Double-Stranded / Q000235:genetics; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism*; D014780:Viruses / Q000276:immunology*
chemical_list: D009692:Nucleic Acid Heteroduplexes; D012330:RNA, Double-Stranded; D034741:RNA, Small Interfering