title: Vectorization of morpholino oligomers by the (R-Ahx-R)4 peptide allows efficient splicing correction in the absence of endosomolytic agents.
abstract: The efficient and non-toxic nuclear delivery of steric-block oligonucleotides (ON) is a prerequisite for therapeutic strategies involving splice correction or exon skipping. Cationic cell penetrating peptides (CPPs) have given rise to much interest for the intracellular delivery of biomolecules, but their efficiency in promoting cytoplasmic or nuclear delivery of oligonucleotides has been hampered by endocytic sequestration and subsequent degradation of most internalized material in endocytic compartments. In the present study, we compared the splice correction activity of three different CPPs conjugated to PMO(705), a steric-block ON targeted against the mutated splicing site of human beta-globin pre-mRNA in the HeLa pLuc705 splice correction model. In contrast to Tat48-60 (Tat) and oligoarginine (R(9)F(2)) PMO(705) conjugates, the 6-aminohexanoic-spaced oligoarginine (R-Ahx-R)(4)-PMO(705) conjugate was able to promote an efficient splice correction in the absence of endosomolytic agents. Our mechanistic investigations about its uptake mechanisms lead to the conclusion that these three vectors are internalized using the same endocytic route involving proteoglycans, but that the (R-Ahx-R)(4)-PMO(705) conjugate has the unique ability to escape from lysosomial fate and to access to the nuclear compartment. This vector, which has displays an extremely low cytotoxicity, the ability to function without chloroquine adjunction and in the presence of serum proteins. It thus offers a promising lead for the development of vectors able to enhance the delivery of therapeutic steric-block ON in clinically relevant models.
authors.affiliation: UMR 5124 CNRS, Université Montpellier 2, place Eugene Bataillon, 34095 Montpellier cedex 5, France.
authors.forename: Saïd
authors.initials: S
authors.lastname: Abes
authors.forename: Hong M
authors.initials: HM
authors.lastname: Moulton
authors.forename: Philippe
authors.initials: P
authors.lastname: Clair
authors.forename: Paul
authors.initials: P
authors.lastname: Prevot
authors.forename: Derek S
authors.initials: DS
authors.lastname: Youngblood
authors.forename: Rebecca P
authors.initials: RP
authors.lastname: Wu
authors.forename: Patrick L
authors.initials: PL
authors.lastname: Iversen
authors.forename: Bernard
authors.initials: B
authors.lastname: Lebleu
mesh_terms: D000818:Animals; D016466:CHO Cells; D018929:Cell Culture Techniques; D002467:Cell Nucleus / Q000187:drug effects / Q000378:metabolism; D006224:Cricetinae; D003412:Cricetulus; D016503:Drug Delivery Systems / Q000379:methods*; D004705:Endocytosis; D011992:Endosomes / Q000187:drug effects / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D009025:Morpholines / Q000008:administration & dosage* / Q000737:chemistry; D060172:Morpholinos; D016376:Oligonucleotides, Antisense / Q000008:administration & dosage* / Q000737:chemistry / Q000493:pharmacokinetics; D020135:Peptide Nucleic Acids / Q000008:administration & dosage* / Q000737:chemistry / Q000494:pharmacology; D010455:Peptides / Q000008:administration & dosage* / Q000737:chemistry / Q000494:pharmacology; D022821:RNA Splice Sites / Q000187:drug effects; D012326:RNA Splicing / Q000187:drug effects*
chemical_list: D009025:Morpholines; D060172:Morpholinos; D016376:Oligonucleotides, Antisense; D020135:Peptide Nucleic Acids; D010455:Peptides; D022821:RNA Splice Sites