title: A new potent secondary amphipathic cell-penetrating peptide for siRNA delivery into mammalian cells.
abstract: RNA interference constitutes a powerful tool for biological studies, but has also become one of the most challenging therapeutic strategies. However, small interfering RNA (siRNA)-based strategies suffer from their poor delivery and biodistribution. Cell-penetrating peptides (CPPs) have been shown to improve the intracellular delivery of various biologically active molecules into living cells and have more recently been applied to siRNA delivery. To improve cellular uptake of siRNA into challenging cell lines, we have designed a secondary amphipathic peptide (CADY) of 20 residues combining aromatic tryptophan and cationic arginine residues. CADY adopts a helical conformation within cell membranes, thereby exposing charged residues on one side, and Trp groups that favor cellular uptake on the other. We show that CADY forms stable complexes with siRNA, thereby increasing their stability and improving their delivery into a wide variety of cell lines, including suspension and primary cell lines. CADY-mediated delivery of subnanomolar concentrations of siRNA leads to significant knockdown of the target gene at both the mRNA and protein levels. Moreover, we demonstrate that CADY is not toxic and enters cells through a mechanism which is independent of the major endosomal pathway. Given its biological properties, we propose that CADY-based technology will have a significant effect on the development of fundamental and therapeutic siRNA-based applications.
authors.affiliation: Centre de Recherches de Biochimie Macromoléculaire, Department of Molecular Biophysics and Therapeutics, Centre Nationale de la Recherche Scientifique, UMR-5237, University of Montpellier I & II, Montpellier, France.
authors.forename: Laurence
authors.initials: L
authors.lastname: Crombez
authors.forename: Gudrun
authors.initials: G
authors.lastname: Aldrian-Herrada
authors.forename: Karidia
authors.initials: K
authors.lastname: Konate
authors.forename: Quan N
authors.initials: QN
authors.lastname: Nguyen
authors.forename: Gary K
authors.initials: GK
authors.lastname: McMaster
authors.forename: Robert
authors.initials: R
authors.lastname: Brasseur
authors.forename: Frederic
authors.initials: F
authors.lastname: Heitz
authors.forename: Gilles
authors.initials: G
authors.lastname: Divita
mesh_terms: D000818:Animals; D015153:Blotting, Western; D045744:Cell Line, Tumor; D002942:Circular Dichroism; D005434:Flow Cytometry; D018014:Gene Transfer Techniques; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D051379:Mice; D008958:Models, Molecular; D010455:Peptides / Q000737:chemistry* / Q000235:genetics*; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D034741:RNA, Small Interfering / Q000235:genetics*; D013050:Spectrometry, Fluorescence
chemical_list: D010455:Peptides; D034741:RNA, Small Interfering