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Soler-Bistué A, Zorreguieta A, Tolmasky ME. Bridged Nucleic Acids Reloaded. Molecules 2019; 24:E2297. [PMID: 31234313 PMCID: PMC6630285 DOI: 10.3390/molecules24122297] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 06/17/2019] [Accepted: 06/18/2019] [Indexed: 12/18/2022] Open
Abstract
Oligonucleotides are key compounds widely used for research, diagnostics, and therapeutics. The rapid increase in oligonucleotide-based applications, together with the progress in nucleic acids research, has led to the design of nucleotide analogs that, when part of these oligomers, enhance their efficiency, bioavailability, or stability. One of the most useful nucleotide analogs is the first-generation bridged nucleic acids (BNA), also known as locked nucleic acids (LNA), which were used in combination with ribonucleotides, deoxyribonucleotides, or other analogs to construct oligomers with diverse applications. However, there is still room to improve their efficiency, bioavailability, stability, and, importantly, toxicity. A second-generation BNA, BNANC (2'-O,4'-aminoethylene bridged nucleic acid), has been recently made available. Oligomers containing these analogs not only showed less toxicity when compared to LNA-containing compounds but, in some cases, also exhibited higher specificity. Although there are still few applications where BNANC-containing compounds have been researched, the promising results warrant more effort in incorporating these analogs for other applications. Furthermore, newer BNA compounds will be introduced in the near future, offering great hope to oligonucleotide-based fields of research and applications.
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Affiliation(s)
- Alfonso Soler-Bistué
- Instituto de Investigaciones Biotecnológicas Dr. Rodolfo A. Ugalde, Instituto Tecnológico de Chascomús, CONICET, Universidad Nacional de San Martín, San Martín 1650, Argentina.
| | - Angeles Zorreguieta
- Fundación Instituto Leloir, IIBBA-CONICET, Buenos Aires C1405BWE, Argentina.
| | - Marcelo E Tolmasky
- Center for Applied Biotechnology Studies, Department of Biological Science, California State University Fullerton, Fullerton, CA 92834-6850, USA.
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2
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Aguilera LU, Rodríguez-González J. Modeling the effect of tat inhibitors on HIV latency. J Theor Biol 2019; 473:20-27. [PMID: 31004612 DOI: 10.1016/j.jtbi.2019.04.018] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Revised: 02/07/2019] [Accepted: 04/16/2019] [Indexed: 11/28/2022]
Abstract
Even in the presence of a successful combination therapy stalling the progress of AIDS, developing a cure for this disease is still an open question. One of the major steps towards a cure would be to be able to eradicate latent HIV reservoirs present in patients. During the last decade, multiple findings point to the dominant role of the viral protein Tat in the establishment of latency. Here we present a mathematical study to understand the potential role of Tat inhibitors as virus-suppressing agents. For this aim, we implemented a computational model that reproduces intracellular dynamics. Simulating an HIV-infected cell and its intracellular feedback we observed that removing Tat protein from the system via inhibitors resulted in a temporary and reversible viral suppression. In contrast, we observed that compounds that interact with Tat protein and disrupt the integrated viral genome produced a more permanent viral suppression.
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Affiliation(s)
- Luis U Aguilera
- Department of Modeling of Biological Processes, COS Heidelberg / Bioquant, Heidelberg University, Im Neuenheimer Feld 267, Heidelberg 69120, Germany; Colorado State University
| | - Jesús Rodríguez-González
- Centro de Investigación y Estudios Avanzados del Instituto Politécnico Nacional, Unidad Monterrey, Via del Conocimiento 201, Parque PIIT, Apodaca CP 66600 NL, México.
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3
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Aupy P, Echevarría L, Relizani K, Goyenvalle A. The Use of Tricyclo-DNA Oligomers for the Treatment of Genetic Disorders. Biomedicines 2017; 6:E2. [PMID: 29271929 PMCID: PMC5874659 DOI: 10.3390/biomedicines6010002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Revised: 12/13/2017] [Accepted: 12/19/2017] [Indexed: 01/16/2023] Open
Abstract
Antisense Oligonucleotides (ASOs) represent very attractive therapeutic compounds for the treatment of numerous diseases. The antisense field has remarkably progressed over the last few years with the approval of the first antisense drugs and with promising developments of more potent and nuclease resistant chemistries. Despite these recent clinical successes and advances in chemistry and design, effective delivery of ASOs to their target tissues remains a major issue. This review will describe the latest advances obtained with the tricyclo-DNA (tcDNA) chemistry which displays unique pharmacological properties and unprecedented uptake in many tissues after systemic administration. We will examine the variety of therapeutic approaches using both fully modified tcDNA-ASOs and gapmers, including splice switching applications, correction of aberrant splicing, steric blocking strategies and targeted gene knock-down mediated by RNase H recruitment. We will then discuss the merits and potential liabilities of the tcDNA chemistry in the context of ASO drug development.
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Affiliation(s)
- Philippine Aupy
- INSERM U1179, UFR des Sciences de la Santé, University of Versailles St-Quentin, 78180 Montigny le Bretonneux, France.
| | - Lucía Echevarría
- INSERM U1179, UFR des Sciences de la Santé, University of Versailles St-Quentin, 78180 Montigny le Bretonneux, France.
- SQY Therapeutics, University of Versailles St-Quentin, 78180 Montigny le Bretonneux, France.
| | - Karima Relizani
- INSERM U1179, UFR des Sciences de la Santé, University of Versailles St-Quentin, 78180 Montigny le Bretonneux, France.
- SQY Therapeutics, University of Versailles St-Quentin, 78180 Montigny le Bretonneux, France.
| | - Aurélie Goyenvalle
- INSERM U1179, UFR des Sciences de la Santé, University of Versailles St-Quentin, 78180 Montigny le Bretonneux, France.
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4
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Kauppinen S, Vester B, Wengel J. Locked nucleic acid (LNA): High affinity targeting of RNA for diagnostics and therapeutics. DRUG DISCOVERY TODAY. TECHNOLOGIES 2014; 2:287-90. [PMID: 24981949 PMCID: PMC7105916 DOI: 10.1016/j.ddtec.2005.08.012] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Locked nucleic acid (LNA) is a nucleic acid analogue containing one or more LNA nucleotide monomers with a bicyclic furanose unit locked in an RNA mimicking sugar conformation. This conformational restriction results in unprecedented hybridization affinity towards complementary single stranded RNA and thus, makes LNA uniquely suited for mimicking RNA structures and sequence specific targeting of RNA in vitro or in vivo. The focus of this paper is on LNA-antisense, LNA-modified siRNA (siLNA), and detection and analysis of microRNAs by LNA-modified oligonucleotide probes. Steve Gullans – RxGen, Inc., New Haven, CT, USA Robert Zivin – Johnson and Johnson, New Brunswick, NJ, USA
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Affiliation(s)
- Sakari Kauppinen
- Wilhelm Johannsen Centre for Functional Genome Research, Institute of Medical Biochemistry and Genetics, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark
| | - Birte Vester
- Nucleic Acid Center, Department of Biochemistry and Molecular Biology, University of Southern Denmark, DK-5230 Odense M, Denmark
| | - Jesper Wengel
- Nucleic Acid Center, Department of Chemistry, University of Southern Denmark, DK-5230 Odense M, Denmark.
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5
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Kumar P, Baral B, Anderson BA, Guenther DC, Østergaard ME, Sharma PK, Hrdlicka PJ. C5-alkynyl-functionalized α-L-LNA: synthesis, thermal denaturation experiments and enzymatic stability. J Org Chem 2014; 79:5062-73. [PMID: 24797769 PMCID: PMC4049248 DOI: 10.1021/jo5006153] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2014] [Indexed: 12/23/2022]
Abstract
Major efforts are currently being devoted to improving the binding affinity, target specificity, and enzymatic stability of oligonucleotides used for nucleic acid targeting applications in molecular biology, biotechnology, and medicinal chemistry. One of the most popular strategies toward this end has been to introduce additional modifications to the sugar ring of affinity-inducing conformationally restricted nucleotide building blocks such as locked nucleic acid (LNA). In the preceding article in this issue, we introduced a different strategy toward this end, i.e., C5-functionalization of LNA uridines. In the present article, we extend this strategy to α-L-LNA: i.e., one of the most interesting diastereomers of LNA. α-L-LNA uridine monomers that are conjugated to small C5-alkynyl substituents induce significant improvements in target affinity, binding specificity, and enzymatic stability relative to conventional α-L-LNA. The results from the back-to-back articles therefore suggest that C5-functionalization of pyrimidines is a general and synthetically straightforward approach to modulate biophysical properties of oligonucleotides modified with LNA or other conformationally restricted monomers.
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Affiliation(s)
- Pawan Kumar
- Department of Chemistry, University of Idaho, Moscow, Idaho 83844-2343, United States
- Department of Chemistry, Kurukshetra University, Kurukshetra 136119, India
| | - Bharat Baral
- Department of Chemistry, University of Idaho, Moscow, Idaho 83844-2343, United States
| | - Brooke A. Anderson
- Department of Chemistry, University of Idaho, Moscow, Idaho 83844-2343, United States
| | - Dale C. Guenther
- Department of Chemistry, University of Idaho, Moscow, Idaho 83844-2343, United States
| | - Michael E. Østergaard
- Department of Chemistry, University of Idaho, Moscow, Idaho 83844-2343, United States
| | - Pawan K. Sharma
- Department of Chemistry, Kurukshetra University, Kurukshetra 136119, India
| | - Patrick J. Hrdlicka
- Department of Chemistry, University of Idaho, Moscow, Idaho 83844-2343, United States
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6
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Mizrahi RA, Schirle NT, Beal PA. Potent and selective inhibition of A-to-I RNA editing with 2'-O-methyl/locked nucleic acid-containing antisense oligoribonucleotides. ACS Chem Biol 2013; 8:832-9. [PMID: 23394403 DOI: 10.1021/cb300692k] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
ADARs (adenosine deaminases acting on RNA) are RNA editing enzymes that bind double helical RNAs and deaminate select adenosines (A). The product inosine (I) is read during translation as guanosine (G), so such changes can alter codon meaning. ADAR-catalyzed A to I changes occur in coding sequences for several proteins of importance to the nervous system. However, these sites constitute only a very small fraction of known A to I sites in the human transcriptome, and the significance of editing at the vast majority sites is unknown at this time. Site-selective inhibitors of RNA editing are needed to advance our understanding of the function of editing at specific sites. Here we show that 2'-O-methyl/locked nucleic acid (LNA) mixmer antisense oligonucleotides are potent and selective inhibitors of RNA editing on two different target RNAs. These reagents are capable of binding with high affinity to RNA editing substrates and remodeling the secondary structure by a strand-invasion mechanism. The potency observed here for 2'-O-methyl/LNA mixmers suggests this backbone structure is superior to the morpholino backbone structure for inhibition of RNA editing. Finally, we demonstrate antisense inhibition of editing of the mRNA for the DNA repair glycosylase NEIL1 in cultured human cells, providing a new approach to exploring the link between RNA editing and the cellular response to oxidative DNA damage.
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Affiliation(s)
- Rena A. Mizrahi
- Department of Chemistry, University of California, Davis, California 95616, United States
| | - Nicole T. Schirle
- Department of Chemistry, University of California, Davis, California 95616, United States
| | - Peter A. Beal
- Department of Chemistry, University of California, Davis, California 95616, United States
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7
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Penn AC, Balik A, Greger IH. Steric antisense inhibition of AMPA receptor Q/R editing reveals tight coupling to intronic editing sites and splicing. Nucleic Acids Res 2012; 41:1113-23. [PMID: 23172291 PMCID: PMC3553965 DOI: 10.1093/nar/gks1044] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Adenosine-to-Inosine (A-to-I) RNA editing is a post-transcriptional mechanism, evolved to diversify the transcriptome in metazoa. In addition to wide-spread editing in non-coding regions protein recoding by RNA editing allows for fine tuning of protein function. Functional consequences are only known for some editing sites and the combinatorial effect between multiple sites (functional epistasis) is currently unclear. Similarly, the interplay between RNA editing and splicing, which impacts on post-transcriptional gene regulation, has not been resolved. Here, we describe a versatile antisense approach, which will aid resolving these open questions. We have developed and characterized morpholino oligos targeting the most efficiently edited site—the AMPA receptor GluA2 Q/R site. We show that inhibition of editing closely correlates with intronic editing efficiency, which is linked to splicing efficiency. In addition to providing a versatile tool our data underscore the unique efficiency of a physiologically pivotal editing site.
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Affiliation(s)
- Andrew C Penn
- Neurobiology Division, MRC Laboratory of Molecular Biology, CB2 0QH Cambridge, UK.
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8
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Torres AG, Threlfall RN, Gait MJ. Potent and sustained cellular inhibition of miR-122 by lysine-derivatized peptide nucleic acids (PNA) and phosphorothioate locked nucleic acid (LNA)/2'-O-methyl (OMe) mixmer anti-miRs in the absence of transfection agents. ARTIFICIAL DNA, PNA & XNA 2012; 2:71-8. [PMID: 22567190 DOI: 10.4161/adna.17731] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Efficient cell delivery of antisense oligonucleotides (ONs) is a key issue for their potential therapeutic use. It has been shown recently that some ONs can be delivered into cells without the use of transfection agents (gymnosis), but this generally requires cell incubation over several days and high amounts of ONs (micromolar concentrations). Here we have targeted microRNA 122 (miR-122), a small non-coding RNA involved in regulation of lipid metabolism and in the replication of hepatitis C virus, with ONs of different chemistries (anti-miRs) by gymnotic delivery in cell culture. Using a sensitive dual-luciferase reporter assay, anti-miRs were screened for their ability to enter liver cells gymnotically and inhibit miR-122 activity. Efficient miR-122 inhibition was obtained with cationic PNAs and 2'-O-methyl (OMe) and Locked Nucleic Acids (LNA)/OMe mixmers containing either phosphodiester (PO) or phosphorothioate (PS) linkages at sub-micromolar concentrations when incubated with cells for just 4 hours. Furthermore, PNA and PS-containing anti-miRs were able to sustain miR-122 inhibitory effects for at least 4 days. LNA/OMe PS anti-miRs were the most potent anti-miR chemistry tested in this study, an ON chemistry that has been little exploited so far as anti-miR agents towards therapeutics.
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Affiliation(s)
- Adrian G Torres
- Medical Research Council, Laboratory of Molecular Biology, Cambridge, UK
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9
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Kumar TS, Madsen AS, Østergaard ME, Sau SP, Wengel J, Hrdlicka PJ. Functionalized 2'-amino-alpha-L-LNA: directed positioning of intercalators for DNA targeting. J Org Chem 2009; 74:1070-81. [PMID: 19108636 PMCID: PMC2853939 DOI: 10.1021/jo802037v] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Chemically modified oligonucleotides are increasingly applied in nucleic acid based therapeutics and diagnostics. LNA (locked nucleic acid) and its diastereomer alpha-L-LNA are two promising examples thereof that exhibit increased thermal and enzymatic stability. Herein, the synthesis, biophysical characterization, and molecular modeling of N2'-functionalized 2'-amino-alpha-L-LNA is described. Chemoselective N2'-functionalization of protected amino alcohol 1 followed by phosphitylation afforded a structurally varied set of target phosphoramidites, which were incorporated into oligodeoxyribonucleotides. Incorporation of pyrene-functionalized building blocks such as 2'-N-(pyren-1-yl)carbonyl-2'-amino-alpha-L-LNA (monomer X) led to extraordinary increases in thermal affinity of up to +19.5 degrees C per modification against DNA targets in particular. In contrast, incorporation of building blocks with small nonaromatic N2'-functionalities such as 2'-N-acetyl-2'-amino-alpha-L-LNA (monomer V) had detrimental effects on thermal affinity toward DNA/RNA complements with decreases of as much as -16.5 degrees C per modification. Extensive thermal DNA selectivity, favorable entropic contributions upon duplex formation, hybridization-induced bathochromic shifts of pyrene absorption maxima and increases in circular dichroism signal intensity, and molecular modeling studies suggest that pyrene-functionalized 2'-amino-alpha-L-LNA monomers W-Y having short linkers between the bicyclic skeleton and the pyrene moiety allow high-affinity hybridization with DNA complements and precise positioning of intercalators in nucleic acid duplexes. This rigorous positional control has been utilized for the development of probes for emerging therapeutic and diagnostic applications focusing on DNA targeting.
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Affiliation(s)
- T Santhosh Kumar
- Nucleic Acid Center, Department of Physics and Chemistry, University of Southern Denmark, DK-5230 Odense M, Denmark
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10
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Veldhoen S, Laufer SD, Restle T. Recent developments in peptide-based nucleic acid delivery. Int J Mol Sci 2008; 9:1276-1320. [PMID: 19325804 PMCID: PMC2635728 DOI: 10.3390/ijms9071276] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2008] [Revised: 06/04/2008] [Accepted: 07/14/2008] [Indexed: 12/20/2022] Open
Abstract
Despite the fact that non-viral nucleic acid delivery systems are generally considered to be less efficient than viral vectors, they have gained much interest in recent years due to their superior safety profile compared to their viral counterpart. Among these synthetic vectors are cationic polymers, branched dendrimers, cationic liposomes and cell-penetrating peptides (CPPs). The latter represent an assortment of fairly unrelated sequences essentially characterised by a high content of basic amino acids and a length of 10–30 residues. CPPs are capable of mediating the cellular uptake of hydrophilic macromolecules like peptides and nucleic acids (e.g. siRNAs, aptamers and antisense-oligonucleotides), which are internalised by cells at a very low rate when applied alone. Up to now, numerous sequences have been reported to show cell-penetrating properties and many of them have been used to successfully transport a variety of different cargos into mammalian cells. In recent years, it has become apparent that endocytosis is a major route of internalisation even though the mechanisms underlying the cellular translocation of CPPs are poorly understood and still subject to controversial discussions. In this review, we will summarise the latest developments in peptide-based cellular delivery of nucleic acid cargos. We will discuss different mechanisms of entry, the intracellular fate of the cargo, correlation studies of uptake versus biological activity of the cargo as well as technical problems and pitfalls.
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Key Words
- CLSM, confocal laser scanning microscopy
- CPP, cell-penetrating peptide
- EIPA, ethylisopropylamiloride
- FCS, fetal calf serum
- GFP, green fluorescent protein
- HEPES, 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid
- HIV, human immunodeficiency virus
- IFN, interferon
- IL, interleukin
- LF, Lipofectamine™
- LF2000, Lipofectamine™ 2000
- MAP, model amphipathic peptide
- MEND, multifunctional envelope-type nano device
- NLS, nuclear localisation sequence
- OMe, O-methyl
- PAMAM, polyamidoamine
- PEG, polyethylene glycol
- PEI, polyethyleneimine
- PMO, phosphorodiamidate morpholino oligomer
- PNA, peptide nucleic acid
- PTD, protein transduction domains
- RNAi, RNA interference
- SAP, Sweet Arrow Peptide
- STR-R8, stearyl-R8
- TAR, transactivator responsive region
- TFO, triplex forming oligonucleotide
- TLR9, toll-like receptor 9
- TNF, tumour necrosis factor
- TP10, transportan 10
- bPrPp, bovine prion protein derived peptide
- cell-penetrating peptides
- endocytosis
- hCT, human calcitonin
- mPrPp, murine prion protein derived peptide
- miRNA, microRNA
- nucleic acid delivery
- nucleic acid drugs
- siRNA, small inhibitory RNA
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Affiliation(s)
- Sandra Veldhoen
- Department of Metabolomics, ISAS - Institute for Analytical Sciences, Bunsen-Kirchhoff-Str. 11, 44139 Dortmund, Germany
- Author to whom correspondence should be addressed; E-mail:
| | - Sandra D. Laufer
- Institut für Molekulare Medizin, Universitätsklinikum Schleswig-Holstein, Universität zu Lübeck, Ratzeburger Allee 160, 23538 Lübeck, Germany
| | - Tobias Restle
- Institut für Molekulare Medizin, Universitätsklinikum Schleswig-Holstein, Universität zu Lübeck, Ratzeburger Allee 160, 23538 Lübeck, Germany
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11
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Fabani MM, Ivanova GD, Gait MJ. Peptide–Peptide Nucleic Acid Conjugates for Modulation of Gene Expression. THERAPEUTIC OLIGONUCLEOTIDES 2008. [DOI: 10.1039/9781847558275-00080] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- Martin M. Fabani
- Medical Research Council Laboratory of Molecular Biology Hills Road Cambridge CB2 0QH UK
| | - Gabriela D. Ivanova
- Medical Research Council Laboratory of Molecular Biology Hills Road Cambridge CB2 0QH UK
| | - Michael J. Gait
- Medical Research Council Laboratory of Molecular Biology Hills Road Cambridge CB2 0QH UK
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12
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Kurreck J. The Role of Backbone Modifications in Oligonucleotide-Based Strategies. THERAPEUTIC OLIGONUCLEOTIDES 2008. [DOI: 10.1039/9781847558275-00001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- Jens Kurreck
- Institute for Chemistry and Biochemistry, Free University Berlin Thielallee 63 14195 Berlin Germany and Institute of Industrial Genetics, University of Stuttgart Allmandring 31 70569 Stuttgart Germany
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13
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Lebleu B, Moulton HM, Abes R, Ivanova GD, Abes S, Stein DA, Iversen PL, Arzumanov AA, Gait MJ. Cell penetrating peptide conjugates of steric block oligonucleotides. Adv Drug Deliv Rev 2008; 60:517-29. [PMID: 18037527 PMCID: PMC7103303 DOI: 10.1016/j.addr.2007.09.002] [Citation(s) in RCA: 141] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2007] [Accepted: 09/10/2007] [Indexed: 12/13/2022]
Abstract
Charge neutral steric block oligonucleotide analogues, such as peptide nucleic acids (PNA) or phosphorodiamidate morpholino oligomers (PMO), have promising biological and pharmacological properties for antisense applications, such as for example in mRNA splicing redirection. However, cellular uptake of free oligomers is poor and the utility of conjugates of PNA or PMO to cell penetrating peptides (CPP), such as Tat or Penetratin, is limited by endosomal sequestration. Two new families of arginine-rich CPPs named (R-Ahx-R)(4) AhxB and R(6)Pen allow efficient nuclear delivery of splice correcting PNA and PMO at micromolar concentrations in the absence of endosomolytic agents. The in vivo efficacy of (R-Ahx-R)(4) AhxB PMO conjugates has been demonstrated in mouse models of Duchenne muscular dystrophy and in various viral infections.
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Affiliation(s)
- Bernard Lebleu
- UMR 5235 CNRS, Université Montpellier 2, Place Eugene Bataillon, 34095 Montpellier cedex 5, France.
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14
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Ivanova G, Arzumanov A, Gait MJ, Reigadas S, Toulmé JJ, Andreola ML, Ittig D, Leumann C. Comparative studies of tricyclo-DNA- and LNA-containing oligonucleotides as inhibitors of HIV-1 gene expression. NUCLEOSIDES NUCLEOTIDES & NUCLEIC ACIDS 2008; 26:747-50. [PMID: 18066894 DOI: 10.1080/15257770701490928] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Trans-activation of HIV-1 transcription is triggered by the interaction of the protein Tat and host cellular factors with a 59-residue stem-loop RNA known as the trans-activation responsive element (TAR). Here we compare the trans-activation steric block inhibitory activity of 16-mer oligonucleotides targeted to TAR containing tricyclo-DNAs, and their mixmers with LNA or OMe residues, with LNA/OMe oligonucleotide. Despite generally weaker TAR RNA binding affinity, all tricyclo-DNA oligonucleotides showed similarly good activity levels to OMe/LNA oligonucleotide in a HeLa Tat-dependent trans-activation cell reporter assay with cationic lipid delivery, but mixmers of tricyclo-DNA were inactive. Tricyclo-DNA 16-mer showed sequence-specific inhibition of beta-galactosidase expression in an anti-HIV HeLa cell reporter assay.
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Affiliation(s)
- Gabriela Ivanova
- Laboratory of Molecular Biology, Medical Research Council, Cambridge, UK
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15
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Fabani MM, Gait MJ. miR-122 targeting with LNA/2'-O-methyl oligonucleotide mixmers, peptide nucleic acids (PNA), and PNA-peptide conjugates. RNA (NEW YORK, N.Y.) 2008; 14:336-46. [PMID: 18073344 PMCID: PMC2212241 DOI: 10.1261/rna.844108] [Citation(s) in RCA: 185] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
MicroRNAs are small noncoding RNAs that regulate many cellular processes in a post-transcriptional mode. MicroRNA knockdown by antisense oligonucleotides is a useful strategy to explore microRNA functionality and as potential therapeutics. MicroRNA-122 (miR-122) is a liver-specific microRNA, the main function of which has been linked with lipid metabolism and liver homeostasis. Here, we show that lipofection of an antisense oligonucleotide based on a Locked Nucleic Acids (LNA)/2'-O-methyl mixmer or electroporation of a Peptide Nucleic Acid (PNA) oligomer is effective at blocking miR-122 activity in human and rat liver cells. These oligonucleotide analogs, evaluated for the first time in microRNA inhibition, are more effective than standard 2'-O-methyl oligonucleotides in binding and inhibiting microRNA action. We also show that microRNA inhibition can be achieved without the need for transfection or electroporation of the human or rat cell lines, by conjugation of an antisense PNA to the cell-penetrating peptide R6-Penetratin, or merely by linkage to just four Lys residues, highlighting the potential of PNA for future therapeutic applications as well as for studying microRNA function.
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Affiliation(s)
- Martin M Fabani
- Medical Research Council, Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
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16
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Kaur H, Babu BR, Maiti S. Perspectives on chemistry and therapeutic applications of Locked Nucleic Acid (LNA). Chem Rev 2007; 107:4672-97. [PMID: 17944519 DOI: 10.1021/cr050266u] [Citation(s) in RCA: 231] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Harleen Kaur
- Institute of Genomics and Integrative Biology, CSIR, Mall Road, Delhi 110 007, India
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17
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Venkatesan N, Kim BH. Peptide conjugates of oligonucleotides: synthesis and applications. Chem Rev 2007; 106:3712-61. [PMID: 16967918 DOI: 10.1021/cr0502448] [Citation(s) in RCA: 131] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Natarajan Venkatesan
- Laboratory for Modified Nucleic Acid Systems, Department of Chemistry, Pohang University of Science and Technology, Pohang 790-784, Korea
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Ivanova G, Reigadas S, Ittig D, Arzumanov A, Andreola ML, Leumann C, Toulmé JJ, Gait MJ. Tricyclo-DNA containing oligonucleotides as steric block inhibitors of human immunodeficiency virus type 1 tat-dependent trans-activation and HIV-1 infectivity. Oligonucleotides 2007; 17:54-65. [PMID: 17461763 DOI: 10.1089/oli.2006.0046] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Replication of human immunodeficiency virus type 1 (HIV-1) is controlled by a variety of viral and host proteins. The viral protein Tat acts in concert with host cellular factors to stimulate transcriptional elongation from the viral long terminal repeat (LTR) through a specific interaction with a 59-residue stem-loop RNA known as the trans-activation responsive element (TAR). Inhibitors of Tat-TAR recognition are expected to block transcription and suppress HIV-1 replication. In previous studies, we showed that 2'-O-methyl (OMe) oligonucleotide mixmers containing locked nucleic acid (LNA) residues are powerful steric block inhibitors of Tat-dependent trans-activation in a HeLa cell reporter system. Here we compare OMe/LNA mixmer oligonucleotides with oligonucleotides containing tricyclo-DNAs and their mixmers with OMe residues in four different assays: (1) binding to the target TAR RNA, (2) Tat-dependent in vitro transcription from an HIV-1 DNA template directed by HeLa cell nuclear extract, (3) trans-activation inhibition in HeLa cells containing a stably integrated firefly luciferase reporter gene under HIV-1 LTR control, and (4) an anti-HIV beta-galactosidase reporter assay of viral infection. Although tricyclo-DNA oligonucleotides bound TAR RNA more weakly, they were as good as OMe/LNA oligonucleotides in suppressing in vitro transcription and trans-activation in HeLa cells when delivered by cationic lipid. No inhibition of in vitro transcription and trans-activation in HeLa cells was observed for tricyclo-DNA/OMe mixmers, even though their affinities to TAR RNA were strong and their cell distributions did not differ from oligonucleotides containing all or predominantly tricyclo-DNA residues. Tricyclo-DNA 16-mer showed sequence-specific inhibition of beta-galactosidase expression in an anti-HIV HeLa cell reporter assay.
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Affiliation(s)
- Gabriela Ivanova
- Medical Research Council, Laboratory of Molecular Biology, Cambridge CB2 2QH, UK
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19
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Ivanova G, Arzumanov AA, Turner JJ, Reigadas S, Toulmé JJ, Brown DE, Lever AML, Gait MJ. Anti-HIV activity of steric block oligonucleotides. Ann N Y Acad Sci 2007; 1082:103-15. [PMID: 17145931 DOI: 10.1196/annals.1348.033] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The unabated increase in spread of HIV infection worldwide has redoubled efforts to discover novel antiviral and virucidal agents that might be starting points for clinical development. Oligonucleotides and their analogs targeted to form complementary duplexes with highly conserved regions of the HIV RNA have shown significant antiviral activity, but to date clinical studies have been dominated by RNase H-inducing oligonucleotide analog phosphorothioates (GEM 91 and 92) that have specificity and efficacy limitations. However, they have proven the principle that oligonucleotides can be safe anti-HIV drugs. Newer oligonucleotide analogs are now available, which act as strong steric block agents of HIV RNA function. We describe our ongoing studies targeting the HIV-1 trans-activation responsive region (TAR) and the viral packaging signal (psi) with steric block oligonucleotides of varying chemistry and demonstrate their great potential for steric blocking of viral protein interactions in vitro and in cells and describe the first antiviral studies. Peptide nucleic acids (PNA) disulfide linked to cell-penetrating peptides (CPP) have been found to have particular promise for the lipid-free direct delivery into cultured cells and are excellent candidates for their development as antiviral and virucidal agents.
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Affiliation(s)
- Gabriela Ivanova
- Medical Research Council, Laboratory of Molecular Biology, Cambridge CB2 2QH, UK
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20
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Di Primo C, Rudloff I, Reigadas S, Arzumanov AA, Gait MJ, Toulmé JJ. Systematic screening of LNA/2'-O-methyl chimeric derivatives of a TAR RNA aptamer. FEBS Lett 2007; 581:771-4. [PMID: 17276430 DOI: 10.1016/j.febslet.2007.01.047] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2007] [Accepted: 01/22/2007] [Indexed: 11/23/2022]
Abstract
We synthesized and evaluated by surface plasmon resonance 64 LNA/2'-O-methyl sequences corresponding to all possible combinations of such residues in a kissing aptamer loop complementary to the 6-nt loop of the TAR element of HIV-1. Three combinations of LNA/2'-O-methyl nucleoside analogues where one or two LNA units are located on the 3' side of the aptamer loop display an affinity for TAR below 1nM, i.e. one order of magnitude higher than the parent RNA aptamer. One of these combinations inhibits the TAR-dependent luciferase expression in a cell assay.
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Affiliation(s)
- Carmelo Di Primo
- INSERM U869, Institut Européen de Chimie et Biologie, 2 rue Escarpit, Pessac cedex, F-33607, France.
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21
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Turner JJ, Jones S, Fabani MM, Ivanova G, Arzumanov AA, Gait MJ. RNA targeting with peptide conjugates of oligonucleotides, siRNA and PNA. Blood Cells Mol Dis 2006; 38:1-7. [PMID: 17113327 DOI: 10.1016/j.bcmd.2006.10.003] [Citation(s) in RCA: 124] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2006] [Revised: 10/05/2006] [Accepted: 10/05/2006] [Indexed: 11/22/2022]
Abstract
Towards the development of oligonucleotide analogues and siRNA as drugs, one potential alternative to the use of liposomal transfection agents is the covalent conjugation of a cell-penetrating peptide (CPP), with the intention of imparting on the oligonucleotide or siRNA an enhanced ability to enter mammalian cells and reach the appropriate RNA target. We have developed robust methods for the chemical synthesis of disulfide-linked conjugates of oligonucleotide analogues, siRNA and peptide nucleic acids (PNA) with a range of cationic and other CPPs. In a HeLa cell assay with integrated plasmid reporters of Tat-dependent trans-activation at the TAR RNA target in the cell nucleus, we were unable to obtain steric block inhibition of gene expression for conjugates of CPPs with a 12-mer oligonucleotide mixmer of 2'-O-methyl and locked nucleic acids units. By contrast, we were able to obtain some reductions in expression of P38alpha MAP kinase mRNA in HeLa cells using microM concentrations of Penetratin or Tat peptides conjugated to the 3'-end of the sense strand of siRNA. However, the most promising results to date have been with a 16-mer PNA conjugated to the CPP Transportan or a double CPP R(6)-Penetratin, where we have demonstrated Tat-dependent trans-activation inhibition in HeLa cells. Results to date suggest the possibility of development of CPP-PNA conjugates as anti-HIV agents as well as other potential applications involving nuclear cell delivery, such as the redirection of splicing.
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Affiliation(s)
- John J Turner
- Medical Research Council, Laboratory of Molecular Biology, Hills Road, Cambridge, CB2 2QH, UK
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22
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Brown DE, Arzumanov A, Syed S, Gait MJ, Lever AML. Inhibition of HIV-1 replication by oligonucleotide analogues directed to the packaging signal and trans-activating response region. Antivir Chem Chemother 2006; 17:1-9. [PMID: 16542000 DOI: 10.1177/095632020601700101] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
HIV possesses a remarkable capacity for mutational escape from therapeutics that target the viral proteins and enzymes. Inhibitory strategies aimed at highly conserved nucleic acid sequences within the genome are an attractive alternative. However, it has proven difficult to achieve an effective level of therapeutic at the appropriate site within the cell. Oligonucleotide delivery is a rapidly advancing field. We have investigated oligonucleotide analogues as steric-block therapeutics against two highly conserved regions of the HIV-1 genome. In the study we show that 2'0-methyl/locked nucleic acid oligonucleotides against the packaging signal and trans-activating response regions of HIV can inhibit replication of the virus.
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Affiliation(s)
- Douglas E Brown
- University of Cambridge, Department of Medicine, Addenbrooke's Hospital, Cambridge, UK
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Erdmann V, Barciszewski J, Brosius J. Locked nucleic acid: high-affinity targeting of complementary RNA for RNomics. Handb Exp Pharmacol 2006; 173:405-22. [PMID: 16594628 PMCID: PMC7120141 DOI: 10.1007/3-540-27262-3_21] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Locked nucleic acid (LNA) is a nucleic acid analog containing one or more LNA nucleotide monomers with a bicyclic furanose unit locked in an RNA-mimicking sugar conformation. This conformational restriction is translated into unprecedented hybridization affinity towards complementary single-stranded RNA molecules. That makes fully modified LNAs, LNA/DNA mixmers, or LNA/RNA mixmers uniquely suited for mimicking RNA structures and for RNA targeting in vitro or in vivo. The focus of this chapter is on LNA antisense, LNA-modified DNAzymes (LNAzymes), LNA-modified small interfering (si)RNA (siLNA), LNA-enhanced expression profiling by real-time RT-PCR and detection and analysis of microRNAs by LNA-modified probes.
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Affiliation(s)
- Volker Erdmann
- Institute of Chemistry/Biochemistry, Free University Berlin, Thielallee 63, 14195 Berlin, Germany
| | - Jan Barciszewski
- Institute of Bioorganic Chemistry, Polish Academy of Scienes, Noskowskiego 12/14, 61-704 Poznan, Poland
| | - Jürgen Brosius
- Institute of Experimental Pathology, Molecular Neurobiology (ZMBE), University of Münster, Von-Esmarch-Str. 56, 48149 Münster, Germany
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Brown D, Arzumanov AA, Turner JJ, Stetsenko DA, Lever AML, Gait MJ. Antiviral activity of steric-block oligonucleotides targeting the HIV-1 trans-activation response and packaging signal stem-loop RNAs. NUCLEOSIDES NUCLEOTIDES & NUCLEIC ACIDS 2005; 24:393-6. [PMID: 16247957 DOI: 10.1081/ncn-200059813] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Mixmer oligonucleotides consisting of residues of both 2'-O-methylnucleosides (OMe) and locked nucleic acids (LNA) were designed targeting two stem-loops in the 5'-UTR of HIV-1 RNA, the transactivation response region (TAR), which is the site of binding of the Tat protein, and the SL3 loop, which is the primary packaging element that binds the Gag polyprotein. These oligonucleotides were found to inhibit syncitia formation dose- and sequence-dependently when delivered to HeLa T4 LTR beta-Gal cells and subsequently infected with HIV-1.
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Affiliation(s)
- Douglas Brown
- Department of Medicine, University of Cambridge, Addenbrooke's Hospital, Hills Road, Cambridge CB2 2QQ. UK
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Turner JJ, Ivanova GD, Verbeure B, Williams D, Arzumanov AA, Abes S, Lebleu B, Gait MJ. Cell-penetrating peptide conjugates of peptide nucleic acids (PNA) as inhibitors of HIV-1 Tat-dependent trans-activation in cells. Nucleic Acids Res 2005; 33:6837-49. [PMID: 16321967 PMCID: PMC1301599 DOI: 10.1093/nar/gki991] [Citation(s) in RCA: 186] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The trans-activation response (TAR) RNA stem–loop that occurs at the 5′ end of HIV RNA transcripts is an important antiviral target and is the site of interaction of the HIV-1 Tat protein together with host cellular factors. Oligonucleotides and their analogues targeted to TAR are potential antiviral candidates. We have investigated a range of cell penetrating peptide (CPP) conjugates of a 16mer peptide nucleic acid (PNA) analogue targeted to the apical stem–loop of TAR and show that disulfide-linked PNA conjugates of two types of CPP (Transportan or a novel chimeric peptide R6-Penetratin) exhibit dose-dependent inhibition of Tat-dependent trans-activation in a HeLa cell assay when incubated for 24 h. Activity is reached within 6 h if the lysosomotropic reagent chloroquine is co-administered. Fluorescein-labelled stably-linked conjugates of Tat, Transportan or Transportan TP10 with PNA were inactive when delivered alone, but attained trans-activation inhibition in the presence of chloroquine. Confocal microscopy showed that such fluorescently labelled CPP–PNA conjugates were sequestered in endosomal or membrane-bound compartments of HeLa cells, which varied in appearance depending on the CPP type. Co-administration of chloroquine was seen in some cases to release fluorescence from such compartments into the nucleus, but with different patterns depending on the CPP. The results show that CPP–PNA conjugates of different types can inhibit Tat-dependent trans-activation in HeLa cells and have potential for development as antiviral agents. Endosomal or membrane release is a major factor limiting nuclear delivery and trans-activation inhibition.
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Affiliation(s)
| | | | | | | | | | - Saïd Abes
- UMR 5124 CNRS, CC 086, Université Montpellier 2Place Eugène Bataillon, 34095 Montpellier, France
| | - Bernard Lebleu
- UMR 5124 CNRS, CC 086, Université Montpellier 2Place Eugène Bataillon, 34095 Montpellier, France
| | - Michael J. Gait
- To whom correspondence should be addressed. Tel: +44 1223 248011; Fax: +44 1223 402070;
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Turner JJ, Fabani M, Arzumanov AA, Ivanova G, Gait MJ. Targeting the HIV-1 RNA leader sequence with synthetic oligonucleotides and siRNA: chemistry and cell delivery. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2005; 1758:290-300. [PMID: 16337923 DOI: 10.1016/j.bbamem.2005.10.013] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2005] [Revised: 10/27/2005] [Accepted: 10/28/2005] [Indexed: 01/22/2023]
Abstract
New candidates for development as potential drugs or virucides against HIV-1 infection and AIDS continue to be needed. The HIV-1 RNA leader sequence has many essential functional sites for virus replication and regulation that includes several highly conserved sequences. The review describes the historical context of targeting the HIV-1 RNA leader sequence with antisense phosphorothioate oligonucleotides, such as GEM 91, and goes on to describe modern approaches to targeting this region with steric blocking oligonucleotide analogues having newer and more advantageous chemistries, as well as recent studies on siRNA, towards the attainment of antiviral activity. Recent attempts to obtain improved cell delivery are highlighted, including exciting new developments in the use of peptide conjugates of peptide nucleic acid (PNA) as potential virucides.
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Affiliation(s)
- John J Turner
- Medical Research Council, Laboratory of Molecular Biology, Hills Road, Cambridge, CB2 2QH, UK
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27
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Jiang M, Arzumanov AA, Gait MJ, Milner J. A bi-functional siRNA construct induces RNA interference and also primes PCR amplification for its own quantification. Nucleic Acids Res 2005; 33:e151. [PMID: 16214804 PMCID: PMC1253835 DOI: 10.1093/nar/gni144] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
RNA interference (RNAi) is a process of post-transcriptional gene silencing initiated by double-stranded RNAs, including short interfering RNA (siRNA). Silencing is sequence-specific and RNAi has rapidly become central to the study of gene function. RNAi also carries promise for selective silencing of viral and endogenous genes causal for disease. To detect the very low levels of siRNA effective for RNAi we modified the 3′ end of the sense strand of siRNA with a nuclease-resistant DNA hairpin. We show that the modified siRNA-DNA construct (termed ‘crook’ siRNA) functions as a primer for the PCR and describe a novel, yet simple PCR protocol for its quantification (amolar levels/cell). When transfected into mammalian cells, crook siRNA induces selective mRNA knock-down equivalent to its unmodified siRNA counterpart. This new bifunctional siRNA construct will enable future in vivo studies on the uptake, distribution and pharmacokinetics of siRNA, and is particularly important for the development of siRNA-based therapeutics. More generally, PCR-based detection of siRNA carries wide-ranging applications for RNAi reverse genetics.
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Affiliation(s)
| | - Andrey A. Arzumanov
- Medical Research Council, Laboratory of Molecular BiologyHills Road, Cambridge CB2 2QH, UK
| | - Michael J. Gait
- Medical Research Council, Laboratory of Molecular BiologyHills Road, Cambridge CB2 2QH, UK
| | - Jo Milner
- To whom correspondence should be addressed. Tel: +44 1904 328620; Fax: +44 1904 328622;
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Affiliation(s)
- Henrik Orum
- CSO Santaris Pharma A/S,, Hørsholm, Denmark.
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Turner JJ, Arzumanov AA, Gait MJ. Synthesis, cellular uptake and HIV-1 Tat-dependent trans-activation inhibition activity of oligonucleotide analogues disulphide-conjugated to cell-penetrating peptides. Nucleic Acids Res 2005; 33:27-42. [PMID: 15640444 PMCID: PMC546131 DOI: 10.1093/nar/gki142] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Oligonucleotides composed of 2′-O-methyl and locked nucleic acid residues complementary to HIV-1 trans-activation responsive element TAR block Tat-dependent trans-activation in a HeLa cell assay when delivered by cationic lipids. We describe an improved procedure for synthesis and purification under highly denaturing conditions of 5′-disulphide-linked conjugates of 3′-fluorescein labelled oligonucleotides with a range of cell-penetrating peptides and investigate their abilities to enter HeLa cells and block trans-activation. Free uptake of 12mer OMe/LNA oligonucleotide conjugates to Tat (48–58), Penetratin and R9F2 was observed in cytosolic compartments of HeLa cells. Uptake of the Tat conjugate was enhanced by N-terminal addition of four Lys or Arg residues or a second Tat peptide. None of the conjugates entered the nucleus or inhibited trans-activation when freely delivered, but inhibition was obtained in the presence of cationic lipids. Nuclear exclusion was seen for free delivery of Tat (48–58), Penetratin and R9 conjugates of 16mer phosphorothioate OMe oligonucleotide. Uptake into human fibroblast cytosolic compartments was seen for Tat, Penetratin, R9F2 and Transportan conjugates. Large enhancements of HeLa cell uptake into cytosolic compartments were seen when free Tat peptide was added to Tat conjugate of 12mer OMe/LNA oligonucleotide or Penetratin peptide to Penetratin conjugate of the same oligonucleotide.
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Affiliation(s)
| | | | - Michael J. Gait
- To whom correspondence should be addressed. Tel: +44 1223 248011; Fax: +44 1223 402070;
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