title: Chemical structure requirements and cellular targeting of microRNA-122 by peptide nucleic acids anti-miRs.
abstract: Anti-miRs are oligonucleotide inhibitors complementary to miRNAs that have been used extensively as tools to gain understanding of specific miRNA functions and as potential therapeutics. We showed previously that peptide nucleic acid (PNA) anti-miRs containing a few attached Lys residues were potent miRNA inhibitors. Using miR-122 as an example, we report here the PNA sequence and attached amino acid requirements for efficient miRNA targeting and show that anti-miR activity is enhanced substantially by the presence of a terminal-free thiol group, such as a Cys residue, primarily due to better cellular uptake. We show that anti-miR activity of a Cys-containing PNA is achieved by cell uptake through both clathrin-dependent and independent routes. With the aid of two PNA analogues having intrinsic fluorescence, thiazole orange (TO)-PNA and [bis-o-(aminoethoxy)phenyl]pyrrolocytosine (BoPhpC)-PNA, we explored the subcellular localization of PNA anti-miRs and our data suggest that anti-miR targeting of miR-122 may take place in or associated with endosomal compartments. Our findings are valuable for further design of PNAs and other oligonucleotides as potent anti-miR agents.
authors: Medical Research Council, Laboratory of Molecular Biology, Hills Road, Cambridge CB2 0QH, UK.
authors: Adrian G
authors: AG
authors: Torres
authors: Martin M
authors: MM
authors: Fabani
authors: Elena
authors: E
authors: Vigorito
authors: Donna
authors: D
authors: Williams
authors: Naowras
authors: N
authors: Al-Obaidi
authors: Filip
authors: F
authors: Wojciechowski
authors: Robert H E
authors: RH
authors: Hudson
authors: Oliver
authors: O
authors: Seitz
authors: Michael J
authors: MJ
authors: Gait
mesh_terms: D000596:Amino Acids / Q000737:chemistry; D002460:Cell Line; D004705:Endocytosis; D011992:Endosomes; D006801:Humans; D035683:MicroRNAs / Q000037:antagonists & inhibitors*; D020135:Peptide Nucleic Acids / Q000032:analysis / Q000737:chemistry* / Q000378:metabolism*; D013438:Sulfhydryl Compounds / Q000737:chemistry; D015854:Up-Regulation
chemical_list: D000596:Amino Acids; D035683:MicroRNAs; D020135:Peptide Nucleic Acids; D013438:Sulfhydryl Compounds