title: Allele-Selective Inhibition of Mutant Huntingtin with 2-Thio- and C5- Triazolylphenyl-Deoxythymidine-Modified Antisense Oligonucleotides.
abstract: We report the effect of introducing a single incorporation of 2-thio-deoxythymidine (2S-dT) or C5-Triazolylphenyl-deoxythymidine (5-TrPh-dT) at four positions within the gap region of RNase H gapmer antisense oligonucleotides (ASOs) for reducing wild-type and mutant huntingtin mRNA in human patient fibroblasts. We show that these modifications can modulate processing of the ASO/RNA heteroduplexes by recombinant human RNase H1 in a position-dependent manner. We also created a structural model of the catalytic domain of human RNase H bound to ASO/RNA heteroduplexes to rationalize the activity and selectivity observations in cells and in the biochemical assays. Our results highlight the ability of chemical modifications in the gap region to produce profound changes in ASO behavior.
authors.affiliation: 1 Isis Pharmaceuticals , Carlsbad, California.
authors.forename: Michael E
authors.initials: ME
authors.lastname: Østergaard
authors.affiliation: 2 Department of Physics, Chemistry and Pharmacy, Nucleic Acid Center, University of Southern Denmark , Odense, Denmark .
authors.forename: Pawan
authors.initials: P
authors.lastname: Kumar
authors.affiliation: 1 Isis Pharmaceuticals , Carlsbad, California.
authors.forename: Josh
authors.initials: J
authors.lastname: Nichols
authors.affiliation: 1 Isis Pharmaceuticals , Carlsbad, California.
authors.forename: Andrew
authors.initials: A
authors.lastname: Watt
authors.affiliation: 3 Department of Chemistry, Kurukshetra University , Kurukshetra, India .
authors.forename: Pawan K
authors.initials: PK
authors.lastname: Sharma
authors.affiliation: 2 Department of Physics, Chemistry and Pharmacy, Nucleic Acid Center, University of Southern Denmark , Odense, Denmark .
authors.forename: Poul
authors.initials: P
authors.lastname: Nielsen
authors.affiliation: 1 Isis Pharmaceuticals , Carlsbad, California.
authors.forename: Punit P
authors.initials: PP
authors.lastname: Seth
mesh_terms: D000483:Alleles; D020029:Base Pairing; D001483:Base Sequence; D042622:DNA Repeat Expansion; D006801:Humans; D000071058:Huntingtin Protein; D050505:Mutant Proteins / Q000235:genetics; D009419:Nerve Tissue Proteins / Q000235:genetics*; D016376:Oligonucleotides, Antisense / Q000235:genetics*; D059367:RNA Cleavage; D016914:Ribonuclease H / Q000502:physiology; D013936:Thymidine / Q000031:analogs & derivatives* / Q000235:genetics*
chemical_list: C086055:HTT protein, human; D000071058:Huntingtin Protein; D050505:Mutant Proteins; D009419:Nerve Tissue Proteins; D016376:Oligonucleotides, Antisense; D016914:Ribonuclease H; C078856:ribonuclease HI; D013936:Thymidine