1
|
Fatthalla MI, Abd El Salam HA, Zayed EM, Ibrahim MAA, Pedersen EB. Enone as TFO Linker: Synthesis and Parallel DNA Triplex Stability Evaluation. ChemistrySelect 2022. [DOI: 10.1002/slct.202202331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Maha I. Fatthalla
- Department of Chemistry Faculty of Science Helwan University 11795 Ain Helwan Cairo Egypt
- Department of Physics Chemistry and Pharmacy University of Southern Denmark Campusvej 55 5230 Odense M Denmark
- Universite Paris-Sud, Faculte de Pharmacie, 5 rue J.-B. Clement Chatenay-Malabry 92296 France
| | | | - Ehab M. Zayed
- Green Chemistry Department National Research Centre Dokki Giza 12622 Egypt
| | - Mahmoud A. A. Ibrahim
- Computational Chemistry Laboratory Chemistry Department Faculty of Science Minia University Minia 61519 Egypt
| | - Erik B. Pedersen
- Department of Physics Chemistry and Pharmacy University of Southern Denmark Campusvej 55 5230 Odense M Denmark
| |
Collapse
|
2
|
Géci I, Fatthalla MI, Heintz M, Jørgensen PT, Pedersen EB. Hoogsteen triplexes stabilized through ethynyl-linked pyrene-indole synthesized by high-temperature Sonogashira coupling. Org Biomol Chem 2022; 20:8873-8884. [PMID: 36102841 DOI: 10.1039/d2ob01466a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The low binding affinity of unmodified triplex-forming oligonucleotides (TFO) is the main drawback to their promising utilization in gene therapy. In the present study, we have synthesized DNA intercalator 5-(pyren-1-ylethynyl)indole Y, known as twisted intercalating nucleic acid (TINA), by a Cu-mediated Sonogashira palladium-catalyzed coupling reaction of 1-ethynylpyrene with 5-iodoindole at a high temperature under anaerobic conditions. Coupling with indole C-5 was far more preferable in obtaining stable TINA-indole than enamine site C-3, as neither hydration of the triple bond to ketones nor competitive Glaser-type homocoupling of acetylenes was observed. The insertion of the new TINA monomer Y as a bulge in the middle or at the 5'-end of the oligodeoxynucleotide sequence via a flexible butane-1,2-diol linker showed extraordinary binding potential, resulting in excellent thermal stabilization of Hoogsteen-type triplex- and duplex-deoxyribonucleic acid (DNA) structures which was detected by thermal denaturation studies and supported by circular dichroism (CD). Molecular dynamics AMBER* revealed the lowest energy conformation in which a pyrenyl residue of the TINA monomer Y stacks in the dsDNA part, while an indolyl unit intercalates between the nucleobases of the TFO pattern. Overall the torsionally rigid conjugated TINA system with a decent twisting of 15.1° around acetylene is confirmed here as a requirement for the best fit inside the intercalation site of the triplex, resulting in high TFO-dsDNA affinity.
Collapse
Affiliation(s)
- Imrich Géci
- Department of Medical and Clinical Biophysics, Faculty of Medicine, P. J. Šafárik University in Košice, Trieda SNP 1, 04011 Košice, Slovakia. .,Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, DK-5230, Odense M, Denmark
| | - Maha I Fatthalla
- Department of Chemistry, Faculty of Science, Helwan University, 11795 Ain Helwan, Cairo, Egypt.,Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, DK-5230, Odense M, Denmark.,Universite Paris-Sud, CNRS, Faculte de Pharmacie, 5 rue J.-B. Clement, Chatenay-Malabry, 92296 France
| | - Maike Heintz
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, DK-5230, Odense M, Denmark
| | - Per T Jørgensen
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, DK-5230, Odense M, Denmark
| | - Erik B Pedersen
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, DK-5230, Odense M, Denmark
| |
Collapse
|
3
|
Lauria T, Slator C, McKee V, Müller M, Stazzoni S, Crisp AL, Carell T, Kellett A. A Click Chemistry Approach to Developing Molecularly Targeted DNA Scissors. Chemistry 2020; 26:16782-16792. [PMID: 32706904 DOI: 10.1002/chem.202002860] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2020] [Revised: 07/23/2020] [Indexed: 12/21/2022]
Abstract
Nucleic acid click chemistry was used to prepare a family of chemically modified triplex forming oligonucleotides (TFOs) for application as a new gene-targeted technology. Azide-bearing phenanthrene ligands-designed to promote triplex stability and copper binding-were 'clicked' to alkyne-modified parallel TFOs. Using this approach, a library of TFO hybrids was prepared and shown to effectively target purine-rich genetic elements in vitro. Several of the hybrids provide significant stabilisation toward melting in parallel triplexes (>20 °C) and DNA damage can be triggered upon copper binding in the presence of added reductant. Therefore, the TFO and 'clicked' ligands work synergistically to provide sequence-selectivity to the copper cutting unit which, in turn, confers high stabilisation to the DNA triplex. To extend the boundaries of this hybrid system further, a click chemistry-based di-copper binding ligand was developed to accommodate designer ancillary ligands such as DPQ and DPPZ. When this ligand was inserted into a TFO, a dramatic improvement in targeted oxidative cleavage is afforded.
Collapse
Affiliation(s)
- Teresa Lauria
- School of Chemical Sciences and National Institute for Cellular Biotechnology, Dublin City University, Glasnevin, Dublin, 9, Ireland
| | - Creina Slator
- School of Chemical Sciences and National Institute for Cellular Biotechnology, Dublin City University, Glasnevin, Dublin, 9, Ireland
| | - Vickie McKee
- School of Chemical Sciences and National Institute for Cellular Biotechnology, Dublin City University, Glasnevin, Dublin, 9, Ireland.,Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, 5230, Odense M, Denmark
| | - Markus Müller
- Department of Chemistry, Ludwig-Maximilians-Universität, Butenandtstrasse 5-13, 81377, Munich, Germany
| | - Samuele Stazzoni
- Department of Chemistry, Ludwig-Maximilians-Universität, Butenandtstrasse 5-13, 81377, Munich, Germany
| | - Antony L Crisp
- Department of Chemistry, Ludwig-Maximilians-Universität, Butenandtstrasse 5-13, 81377, Munich, Germany
| | - Thomas Carell
- Department of Chemistry, Ludwig-Maximilians-Universität, Butenandtstrasse 5-13, 81377, Munich, Germany
| | - Andrew Kellett
- School of Chemical Sciences and National Institute for Cellular Biotechnology, Dublin City University, Glasnevin, Dublin, 9, Ireland.,CÚRAM, Centre for Research in Medical Devices, Dublin City University, Glasnevin, Dublin, 9, Ireland
| |
Collapse
|
4
|
Gouda AS, Przypis Ł, Walczak K, Jørgensen PT, Wengel J. Carbazole modified oligonucleotides: synthesis, hybridization studies and fluorescence properties. Org Biomol Chem 2020; 18:6935-6948. [PMID: 32936176 DOI: 10.1039/d0ob01553a] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Synthesis of the novel thiophenyl carbazole phosphoramidite DNA building block 5 was accomplished in four steps using a Suzuki-Miyaura cross-coupling reaction from the core carbazole and it was seamlessly accommodated into a 9-mer DNA-based oligonucleotide by incorporation at the flanking 5'-end in combination with a central insertion of an LNA-T nucleotide. The carbazole-containing oligonucleotide was combined in different duplex hybrids, which were characterized by thermal denaturation, circular dichroism and fluorescence studies. The carbazole monomer modulates the duplex stability in various ways. Thus, monomer Z increased the thermal stability of the 9-mer towards the complementary 9-mer/15-mer DNA duplex by 4.2 °C. Furthermore, indications of its intercalation into the duplex were obtained by modeling studies and robust decreases in fluorescence emission intensities upon duplex formation. In contrast, no clear intercalating tendency was corroborated for monomer Z within the DNA/RNA hybrid duplex as indicated by moderate quenching of the fluorescence and similar duplex thermal stabilities relative to the corresponding control duplex. The recognition efficiencies of the carbazole modified oligonucleotide toward single nucleotide mismatches were studied with two 15-mer model targets (DNA and RNA). For both systems, mismatches positioned at the juxtaposition of the carbazole monomer showed pronounced deceases in thermal denaturation temperature. Steady-state fluorescence emission studies of all mismatched duplexes with incorporation of Z monomer typically displayed efficient fluorescence quenching.
Collapse
Affiliation(s)
- Alaa S Gouda
- Biomolecular Nanoscale Engineering Center, Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, 5230 Odense M, Denmark.
| | | | | | | | | |
Collapse
|
5
|
Osman AMA, Pedersen EB. Conjugation of N-(3-(9-Ethynyl-6 H-indolo[2,3- b]quinoxalin-6-yl)propyl)-2,2,2-trifluoroacetamide Intercalator to a Triplex Forming Oligonucleotide, a Three-Way Junction, and a G-Quadruplex. European J Org Chem 2019. [DOI: 10.1002/ejoc.201900554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Amany M. A. Osman
- Nucleic Acid Center; Department of Physics; Chemistry and Pharmacy; University of Southern Denmark; Campusvej 55 5230 Odense M Denmark
- Chemistry Department; Faculty of Science; Menoufia University; Shebin El-Koam Egypt
| | - Erik B. Pedersen
- Nucleic Acid Center; Department of Physics; Chemistry and Pharmacy; University of Southern Denmark; Campusvej 55 5230 Odense M Denmark
| |
Collapse
|
6
|
Fatthalla MI, Pedersen EB. Unexpected Hydration of a Triple Bond During DNA Synthesis: Conjugating 3-(Pyren-1-ylethynyl)indole to DNA for Triplex Studies. European J Org Chem 2016. [DOI: 10.1002/ejoc.201600287] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Maha I. Fatthalla
- Department of Physics; Chemistry and Pharmacy University of Southern Denmark; Campusvej 55 5230 Odense M Denmark
- Department of Chemistry; Faculty of Science; Helwan University; 11795 Ain Helwan, Cairo Egypt
| | - Erik B. Pedersen
- Department of Physics; Chemistry and Pharmacy University of Southern Denmark; Campusvej 55 5230 Odense M Denmark
| |
Collapse
|
7
|
Cogoi S, Zorzet S, Rapozzi V, Géci I, Pedersen EB, Xodo LE. MAZ-binding G4-decoy with locked nucleic acid and twisted intercalating nucleic acid modifications suppresses KRAS in pancreatic cancer cells and delays tumor growth in mice. Nucleic Acids Res 2013; 41:4049-64. [PMID: 23471001 PMCID: PMC3627599 DOI: 10.1093/nar/gkt127] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
KRAS mutations are primary genetic lesions leading to pancreatic cancer. The promoter of human KRAS contains a nuclease-hypersensitive element (NHE) that can fold in G4-DNA structures binding to nuclear proteins, including MAZ (myc-associated zinc-finger). Here, we report that MAZ activates KRAS transcription. To knockdown oncogenic KRAS in pancreatic cancer cells, we designed oligonucleotides that mimic one of the G-quadruplexes formed by NHE (G4-decoys). To increase their nuclease resistance, two locked nucleic acid (LNA) modifications were introduced at the 3'-end, whereas to enhance the folding and stability, two polycyclic aromatic hydrocarbon units (TINA or AMANY) were inserted internally, to cap the quadruplex. The most active G4-decoy (2998), which had two para-TINAs, strongly suppressed KRAS expression in Panc-1 cells. It also repressed their metabolic activity (IC50 = 520 nM), and it inhibited cell growth and colony formation by activating apoptosis. We finally injected 2998 and control oligonucleotides 5153, 5154 (2 nmol/mouse) intratumorally in SCID mice bearing a Panc-1 xenograft. After three treatments, 2998 reduced tumor xenograft growth by 64% compared with control and increased the Kaplan-Meier median survival time by 70%. Together, our data show that MAZ-specific G4-decoys mimicking a KRAS quadruplex are promising for pancreatic cancer therapy.
Collapse
Affiliation(s)
- Susanna Cogoi
- Department of Medical and Biological Sciences, School of Medicine, P.le Kolbe 4, 33100 Udine, Italy
| | | | | | | | | | | |
Collapse
|
8
|
Rohrbach F, Fatthalla MI, Kupper T, Pötzsch B, Müller J, Petersen M, Pedersen EB, Mayer G. Chemical maturation of a bivalent aptamer by single domain variation. Chembiochem 2012; 13:631-4. [PMID: 22331608 DOI: 10.1002/cbic.201200015] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/1932] [Indexed: 01/28/2023]
Affiliation(s)
- Falk Rohrbach
- Life and Medical Sciences Institute, University of Bonn, Gerhard-Domagk-Strasse 1, 53121 Bonn, Germany
| | | | | | | | | | | | | | | |
Collapse
|
9
|
Fatthalla MI, Elkholy YM, Abbas NS, Mandour AH, Jørgensen PT, Bomholt N, Pedersen EB. Conjugation of a 3-(1H-phenanthro[9,10-d]imidazol-2-yl)-1H-indole intercalator to a triplex oligonucleotide and to a three-way junction. Bioorg Med Chem 2011; 20:207-14. [PMID: 22154560 DOI: 10.1016/j.bmc.2011.11.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2011] [Revised: 11/02/2011] [Accepted: 11/07/2011] [Indexed: 11/29/2022]
Abstract
A new intercalating nucleic acid monomer M comprising a 4-(1-indole)-butane-1,2-diol moiety was synthesized via a classical alkylation reaction of indole-3-carboxaldehyde followed by a condensation reaction with phenanthrene-9,10-dione in the presence of ammonium acetate to form a phenanthroimidazole moiety linked to the indole ring. Insertion of the new intercalator as a bulge into a Triplex Forming Oligonucleotide resulted in good thermal stability of the corresponding Hoogsteen-type triplexes. Molecular modeling supports the possible intercalating ability of M. Hybridisation properties of DNA/DNA and RNA/DNA three-way junctions (TWJ) with M in the branching point were also evaluated by their thermal stability at pH 7. DNA/DNA TWJ showed increase in thermal stability compared to wild type oligonucleotides whereas this was not the case for RNA/DNA TWJ.
Collapse
Affiliation(s)
- Maha I Fatthalla
- Nucleic Acid Center, Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, 5230 Odense M, Denmark
| | | | | | | | | | | | | |
Collapse
|
10
|
Schneider UV, Géci I, Jøhnk N, Mikkelsen ND, Pedersen EB, Lisby G. Increasing the analytical sensitivity by oligonucleotides modified with para- and ortho-twisted intercalating nucleic acids--TINA. PLoS One 2011; 6:e20565. [PMID: 21673988 PMCID: PMC3108614 DOI: 10.1371/journal.pone.0020565] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2011] [Accepted: 05/04/2011] [Indexed: 11/18/2022] Open
Abstract
The sensitivity and specificity of clinical diagnostic assays using DNA hybridization techniques are limited by the dissociation of double-stranded DNA (dsDNA) antiparallel duplex helices. This situation can be improved by addition of DNA stabilizing molecules such as nucleic acid intercalators. Here, we report the synthesis of a novel ortho-Twisted Intercalating Nucleic Acid (TINA) amidite utilizing the phosphoramidite approach, and examine the stabilizing effect of ortho- and para-TINA molecules in antiparallel DNA duplex formation. In a thermal stability assay, ortho- and para-TINA molecules increased the melting point (Tm) of Watson-Crick based antiparallel DNA duplexes. The increase in Tm was greatest when the intercalators were placed at the 5′ and 3′ termini (preferable) or, if placed internally, for each half or whole helix turn. Terminally positioned TINA molecules improved analytical sensitivity in a DNA hybridization capture assay targeting the Escherichia coli rrs gene. The corresponding sequence from the Pseudomonas aeruginosa rrs gene was used as cross-reactivity control. At 150 mM ionic strength, analytical sensitivity was improved 27-fold by addition of ortho-TINA molecules and 7-fold by addition of para-TINA molecules (versus the unmodified DNA oligonucleotide), with a 4-fold increase retained at 1 M ionic strength. Both intercalators sustained the discrimination of mismatches in the dsDNA (indicated by ΔTm), unless placed directly adjacent to the mismatch – in which case they partly concealed ΔTm (most pronounced for para-TINA molecules). We anticipate that the presented rules for placement of TINA molecules will be broadly applicable in hybridization capture assays and target amplification systems.
Collapse
|
11
|
Kolevzon N, Yavin E. Site-Specific DNA Photocleavage and Photomodulation by Oligonucleotide Conjugates. Oligonucleotides 2010; 20:263-75. [DOI: 10.1089/oli.2010.0247] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- Netanel Kolevzon
- The School of Pharmacy, The Institute for Drug Research, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Eylon Yavin
- The School of Pharmacy, The Institute for Drug Research, The Hebrew University of Jerusalem, Jerusalem, Israel
| |
Collapse
|
12
|
Schneider UV, Mikkelsen ND, Jøhnk N, Okkels LM, Westh H, Lisby G. Optimal design of parallel triplex forming oligonucleotides containing Twisted Intercalating Nucleic Acids--TINA. Nucleic Acids Res 2010; 38:4394-403. [PMID: 20338879 PMCID: PMC2910062 DOI: 10.1093/nar/gkq188] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Twisted intercalating nucleic acid (TINA) is a novel intercalator and stabilizer of Hoogsteen type parallel triplex formations (PT). Specific design rules for position of TINA in triplex forming oligonucleotides (TFOs) have not previously been presented. We describe a complete collection of easy and robust design rules based upon more than 2500 melting points (Tm) determined by FRET. To increase the sensitivity of PT, multiple TINAs should be placed with at least 3 nt in-between or preferable one TINA for each half helixturn and/or whole helixturn. We find that ΔTm of base mismatches on PT is remarkably high (between 7.4 and 15.2°C) compared to antiparallel duplexes (between 3.8 and 9.4°C). The specificity of PT by ΔTm increases when shorter TFOs and higher pH are chosen. To increase ΔTms, base mismatches should be placed in the center of the TFO and when feasible, A, C or T to G base mismatches should be avoided. Base mismatches can be neutralized by intercalation of a TINA on each side of the base mismatch and masked by a TINA intercalating direct 3′ (preferable) or 5′ of it. We predict that TINA stabilized PT will improve the sensitivity and specificity of DNA based clinical diagnostic assays.
Collapse
Affiliation(s)
- Uffe V Schneider
- QuantiBact Inc, Department of Clinical Microbiology, Hvidovre Hospital, Kettegaards Alle 30, 2650 Hvidovre, Denmark.
| | | | | | | | | | | |
Collapse
|