title: Targeted intracellular delivery of antisense oligonucleotides via conjugation with small-molecule ligands.
abstract: Selective delivery of antisense or siRNA oligonucleotides to cells and tissues via receptor-mediated endocytosis is becoming an important approach for oligonucleotide-based pharmacology. In most cases receptor targeting has been attained using antibodies or peptide-type ligands. Thus, there are few examples of delivering oligonucleotides using the plethora of small-molecule receptor-specific ligands that currently exist. In this report we describe a facile approach to the generation of mono- and multivalent conjugates of oligonucleotides with small-molecule ligands. Using the sigma-receptor ligand anisamide as an example, we describe conversion of the ligand to a phosphoramidite and direct incorporation of this moiety into the oligonucleotide by solid-phase DNA synthesis. We generated mono- and trivalent conjugates of anisamide with a splice switching antisense oligonucleotide (SSO) and tested their ability to modify splicing of a reporter gene (luciferase) in tumor cells in culture. The trivalent anisamide-SSO conjugate displayed enhanced cellular uptake and was markedly more effective than an unconjugated SSO or the monovalent conjugate in modifying splicing of the reporter. Significant biological effects were attained in the sub-100 nM concentration range.
authors.affiliation: Division of Molecular Pharmaceutics, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, 1072 Genetic Medicine Building, Chapel Hill, North Carolina 27599, USA.
authors.forename: Osamu
authors.initials: O
authors.lastname: Nakagawa
authors.forename: Xin
authors.initials: X
authors.lastname: Ming
authors.forename: Leaf
authors.initials: L
authors.lastname: Huang
authors.forename: Rudolph L
authors.initials: RL
authors.lastname: Juliano
mesh_terms: D000577:Amides / Q000737:chemistry; D001483:Base Sequence; D001692:Biological Transport; D045744:Cell Line, Tumor; D006801:Humans; D042541:Intracellular Space / Q000378:metabolism*; D008024:Ligands; D016376:Oligonucleotides, Antisense / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D017480:Receptors, sigma / Q000378:metabolism
chemical_list: D000577:Amides; D008024:Ligands; D016376:Oligonucleotides, Antisense; D017480:Receptors, sigma