title: Cationic siRNAs provide carrier-free gene silencing in animal cells.
abstract: siRNA-mediated gene silencing requires intracellular delivery of the nucleic acid. We have developed a carrierless molecular approach that follows the same cell entry route as cationic supramolecular complexes, yet should avoid the extracellular barriers encountered by nanoparticles. Cationic oligospermine-oligonucleotide conjugates (ZNAs, for Zip Nucleic Acids) were synthesized stepwise on an oligonucleotide synthesizer using a DMT-spermine phosphoramidite derivative. They were shown to enter cells and have access to the cytoplasm, provided their formal charge ratio N/P was >1.5. Cationic siRNAs that fulfilled this condition were shown to achieve selective inhibition of luciferase gene expression in the submicromolar concentration range in constitutively luciferase-expressing cells.
authors.affiliation: Laboratoire de Chimie Genetique, Universite de Strasbourg and C.N.R.S., Faculte de Pharmacie, 67401 Illkirch, France.
authors.forename: Marc
authors.initials: M
authors.lastname: Nothisen
authors.forename: Mitsuharu
authors.initials: M
authors.lastname: Kotera
authors.forename: Emilie
authors.initials: E
authors.lastname: Voirin
authors.forename: Jean-Serge
authors.initials: JS
authors.lastname: Remy
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: Behr
mesh_terms: D002412:Cations / Q000737:chemistry; D002460:Cell Line; D004305:Dose-Response Relationship, Drug; D020868:Gene Silencing / Q000187:drug effects*; D006367:HeLa Cells; D006801:Humans; D008156:Luciferases / Q000235:genetics / Q000378:metabolism; D009838:Oligodeoxyribonucleotides / Q000138:chemical synthesis / Q000737:chemistry; D034741:RNA, Small Interfering / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D013096:Spermine / Q000737:chemistry
chemical_list: D002412:Cations; D009838:Oligodeoxyribonucleotides; D034741:RNA, Small Interfering; D013096:Spermine; D008156:Luciferases