title: Short antisense oligonucleotide-mediated inhibition is strongly dependent on oligo length and concentration but almost independent of location of the target sequence.
abstract: The inhibitory effect of short antisense oligodeoxynucleotides (aODNs) on cRNA expression in Xenopus oocytes was measured using an electrophysiological assay based on subunit-specific block of cloned alpha-amino-3-hydroxy-5-methyl-4-isoxazole-propionate receptors. The effect of both phosphorothioate-modified (PS) and phosphodiester (PO) aODNs was strongly length dependent with a half-maximal inhibition calculated for an oligo length of 7.6 nucleotides (nt) and 9.9 nt, respectively. More than 95% inhibition was mediated by a PS aODN of 12 nt and by PO aODNs > or = 15 nt. At a given length PS and PO aODNs showed differential dependence of their inhibitory effect on the injected aODN concentration (half-maximal inhibition at 18 ng/microliter for a PO 12-mer and at 0.19 ng/microliter for a PS 12-mer) and differential saturation behavior. The inhibitory effect of aODNs, even as short as 8 nt for PS oligomers, was highly sequence specific, but almost independent of the position of the respective target site on the cRNA (for PS 8-mers, > or = 70% expression inhibition throughout the tested target sites from the translation initiation to the 3'-untranslated region). Thus, short PS aODNs can be reliably used in order to specifically inhibit protein expression in experiments addressing physiological, molecular biological, and perhaps even therapeutical issues.
authors.affiliation: Sektion für Sensorische Biophysik, HNO-Universitätsklinik Tübingen, Germany.
authors.forename: B
authors.initials: B
authors.lastname: Fakler
authors.forename: S
authors.initials: S
authors.lastname: Herlitze
authors.forename: B
authors.initials: B
authors.lastname: Amthor
authors.forename: H P
authors.initials: HP
authors.lastname: Zenner
authors.forename: J P
authors.initials: JP
authors.lastname: Ruppersberg
mesh_terms: D000818:Animals; D001483:Base Sequence; D016373:DNA, Antisense / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004553:Electric Conductivity; D007210:Indoleacetic Acids; D008969:Molecular Sequence Data; D016376:Oligonucleotides, Antisense / Q000494:pharmacology*; D009865:Oocytes; D010648:Phenylacetates / Q000494:pharmacology; D011073:Polyamines / Q000494:pharmacology; D014176:Protein Biosynthesis / Q000187:drug effects*; D018075:RNA, Complementary; D018091:Receptors, AMPA / Q000145:classification / Q000235:genetics*; D013329:Structure-Activity Relationship; D013873:Thionucleotides; D014981:Xenopus / Q000235:genetics
chemical_list: D016373:DNA, Antisense; D007210:Indoleacetic Acids; D016376:Oligonucleotides, Antisense; D010648:Phenylacetates; D011073:Polyamines; D018075:RNA, Complementary; D018091:Receptors, AMPA; D013873:Thionucleotides; C558368:argiotoxin-636