title: Sticky overhangs enhance siRNA-mediated gene silencing.
abstract: siRNA delivery to cells offers a convenient and powerful means of gene silencing that bypasses several barriers met by gene delivery. However, nonviral vectors, and especially polymers, form looser complexes with siRNA than with plasmid DNA. As a consequence, exchange of siRNA for larger polymeric anions such as proteoglycans found outside cells and at their surface may occur and lower delivery. We show here that making siRNAs "gene-like," via short complementary A(5-8)/T(5-8) 3' overhangs, increases complex stability, and hence RNase protection and gene silencing in vitro up to 10-fold. After decomplexation in the cytoplasm, sticky siRNA (ssiRNA) concatemers fall apart. ssiRNAs are therefore not inducing antiviral responses, as shown by the absence of IFN-beta production. Finally, transfection experiments in the mouse lung show that ssiRNA should be particularly suited to silencing with linear polyethylenimine in vivo.
authors.affiliation: Polyplus-Transfection, Bioparc, Boulevard Sebastien Brant, 67400 Illkirch, France.
authors.forename: Anne-Laure
authors.initials: AL
authors.lastname: Bolcato-Bellemin
authors.forename: Marie-Elise
authors.initials: ME
authors.lastname: Bonnet
authors.forename: Gaëlle
authors.initials: G
authors.lastname: Creusat
authors.forename: Patrick
authors.initials: P
authors.lastname: Erbacher
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: Behr
mesh_terms: D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D005260:Female; D005456:Fluorescent Dyes; D017930:Genes, Reporter; D005821:Genetic Techniques; D005822:Genetic Vectors; D006025:Glycosaminoglycans; D006367:HeLa Cells; D006801:Humans; D008055:Lipids; D008156:Luciferases / Q000235:genetics; D008168:Lung / Q000378:metabolism; D051379:Mice; D041681:NIH 3T3 Cells; D011094:Polyethyleneimine; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000008:administration & dosage / Q000737:chemistry* / Q000235:genetics*; D012260:Ribonucleases; D014162:Transfection
chemical_list: D005456:Fluorescent Dyes; D006025:Glycosaminoglycans; D008055:Lipids; D034741:RNA, Small Interfering; D011094:Polyethyleneimine; D008156:Luciferases; D012260:Ribonucleases