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Ouchi Y, Kishino T, Miyashita T, Mori T, Mitamura K, Norikane T, Yamamoto Y, Hoshikawa H. Predictive value of local control by 4'-[methyl-11C]-thiotymidine PET volume parameters in p16-negative oropharyngeal, hypopharyngeal, and supraglottic squamous cell carcinoma. Nucl Med Commun 2024; 45:381-388. [PMID: 38247572 DOI: 10.1097/mnm.0000000000001821] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2024]
Abstract
PURPOSE We investigated the potential of baseline 4'-[methyl- 11 C]-thiothymidine ([ 11 C]4DST) PET for predicting loco-regional control of head and neck squamous cell carcinoma (HNSCC). METHODS A retrospective analysis was performed using volumetric parameters, such as SUVmax, proliferative tumor volume (PTV), and total lesion proliferation (TLP), of pretreatment [ 11 C]4DST PET for 91 patients with HNSCC with primary lesions in the oral cavity, hypopharynx, supraglottis, and oropharynx, which included p16-negative patients. PTV and TLP were calculated for primary lesions and metastatic lymph nodes combined. We examined the association among the parameters and relapse-free survival and whether case selection focused on biological characteristics improved the accuracy of prognosis prediction. RESULTS The area under the curves (AUCs) using PTV and TLP were high for the oropharyngeal/hypopharyngeal/supraglottis groups (0.91 and 0.87, respectively), whereas that of SUVmax was 0.66 ( P < 0.01). On the other hand, the oral group had lower AUCs for PTV and TLP (0.72 and 0.77, respectively). When all cases were examined, the AUCs using PTV and TLP were 0.84 and 0.83, respectively. CONCLUSION Baseline [ 11 C]4DST PET/CT volume-based parameters can provide important prognostic information with p16-negative oropharyngeal, hypopharyngeal, and supraglottic cancer patients.
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Affiliation(s)
- Yohei Ouchi
- Department of Otolaryngology, Faculty of Medicine, Kagawa University and
| | - Takehito Kishino
- Department of Otolaryngology, Faculty of Medicine, Kagawa University and
| | - Takenori Miyashita
- Department of Otolaryngology, Faculty of Medicine, Kagawa University and
| | - Terushige Mori
- Department of Otolaryngology, Faculty of Medicine, Kagawa University and
| | - Katsuya Mitamura
- Department of Radiology, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Takashi Norikane
- Department of Radiology, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Yuka Yamamoto
- Department of Radiology, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Hiroshi Hoshikawa
- Department of Otolaryngology, Faculty of Medicine, Kagawa University and
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Kumar R, Wang T, Veedu RN, Kumar S. Novel 3'-[4-fluoroaryl-(1,2,3-triazol-1-yl)]-3'-deoxythymidine analogues: Design, synthesis, characterization and their potential as anticancer agents. Nucleosides Nucleotides Nucleic Acids 2022; 41:343-360. [PMID: 35094645 DOI: 10.1080/15257770.2022.2029883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 01/11/2022] [Accepted: 01/12/2022] [Indexed: 06/14/2023]
Abstract
Novel 3'-[4-fluoroaryl-(1,2,3-triazol-1-yl)]-3'-deoxythymidine analogues (7a-l) were developed by the Cu alkyne-azide cycloaddition (CuAAC) reaction. The obtained lead compounds were confirmed by using 1H NMR, 13C NMR, 2 D NMR, HRMS and their anticancer activities were screened against Huh-7 liver cancer cells and U87MG human glioblastoma cells. Among the synthesized fluorinated 1,2,3-triazolyl nucleosides, three compounds (7i, 7a-b) demonstrated promising anti-proliferative against Huh-7 and U87MG cell lines. Significantly, compound 7i has displayed remarkable promising anticancer activity with IC50 value in the micromole range (22.41-24.92 µM) and (18.12-21.36 µM) against Huh-7 cancer cells and U87MG glioblastoma cells, respectively.
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Affiliation(s)
- Ritik Kumar
- Department of Chemistry, Deenbandhu Chhotu Ram University of Science and Technology, Murthal, Haryana, India
| | - Tao Wang
- Centre for Molecular Medicine and Innovative Therapeutics, Murdoch University, Perth, Australia
- Perron Institute for Neurological and Translational Science, Perth, Australia
| | - Rakesh N Veedu
- Centre for Molecular Medicine and Innovative Therapeutics, Murdoch University, Perth, Australia
- Perron Institute for Neurological and Translational Science, Perth, Australia
| | - Surender Kumar
- Bioorganic Laboratory, Department of Chemistry, Institute of Integrated & Honors Studies (IIHS), Kurukshetra University, Kurukshetra, Haryana, India
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Osawa T, Yano N, Aoyama H, Obika S. Synthesis, Duplex-Forming Ability, and Nuclease Resistance of Oligonucleotides Containing a Thymidine Derivative with a 1-Oxaspiro[4.5]decane Skeleton. Chem Pharm Bull (Tokyo) 2022; 70:699-706. [PMID: 36184452 DOI: 10.1248/cpb.c22-00458] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Chemically modified nucleic acids are essential for the therapeutic application of oligonucleotides. In this study, 6'-C-spiro-thymidine exhibiting a fixed torsion angle γ was designed, synthesized, and incorporated into oligonucleotides. The conformational analysis of the 6'-C-spiro-thymidine monomer revealed that its torsion angle γ was in the +synclinal range (approx. 60°), which is similar to that in a natural RNA duplex, as expected. On the other hand, the sugar conformation of the RNA duplex is known to be predominantly an N-type, whereas that of the synthesized monomer was an S-type. The results of the UV melting analysis demonstrated that the duplex-forming ability of 6'-C-spiro-thymidine was inferior to that of natural DNA. Contrarily, 6'-C-spiro-thymidine could enhance the stability of oligonucleotides toward nucleases. Particularly, the incorporation of 6'-C-spiro-thymidine on the 3'-ends of the oligonucleotides significantly increased the nuclease resistance of the oligonucleotides.
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Affiliation(s)
- Takashi Osawa
- Graduate School of Pharmaceutical Sciences, Osaka University
| | - Natsumi Yano
- Graduate School of Pharmaceutical Sciences, Osaka University
| | - Hiroshi Aoyama
- Graduate School of Pharmaceutical Sciences, Osaka University
| | - Satoshi Obika
- Graduate School of Pharmaceutical Sciences, Osaka University
- Institute for Open and Transdisciplinary Research Initiatives, Osaka University
- National Institutes of Biomedical Innovation, Health and Nutrition
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4
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Hou H, Li Y, Wang M, Liu A, Yu Z, Chen K, Zhao D, Xu Y. Structural insights into RNA polymerase III-mediated transcription termination through trapping poly-deoxythymidine. Nat Commun 2021; 12:6135. [PMID: 34675218 PMCID: PMC8531034 DOI: 10.1038/s41467-021-26402-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Accepted: 09/24/2021] [Indexed: 01/11/2023] Open
Abstract
Termination of the RNA polymerase III (Pol III)-mediated transcription requires the conversion of an elongation complex (EC) to a pre-termination complex (PTC) on poly-deoxythymidine (dT)-containing non-template strand, a mechanism distinct from Pol I and Pol II. Here, our in vitro transcription elongation assay showed that 5-7 dT-containing DNA template led to transcription termination of Pol III, but not Pol I or Pol II. We assembled human Pol III PTC on a 7 dT-containing DNA template and determined the structure at 3.6 Å resolution. The structure reveals that poly-dT are trapped in a narrow exit tunnel formed by RPC2. A hydrophobic gate of the exit tunnel separates the bases of two connected deoxythymidines and may prevent translocation of the non-template strand. The fork loop 2 stabilizes both template and non-template strands around the transcription fork, and may further prevent strand translocation. Our study shows that the Pol III-specific exit tunnel and FL2 allow for efficient translocation of non-poly-dT sequence during transcription elongation but trap poly-dT to promote DNA retention of Pol III, revealing molecular mechanism of poly-dT-dependent transcription termination of Pol III.
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Affiliation(s)
- Haifeng Hou
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering, Shanghai Key Laboratory of Radiation Oncology, and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai, 200032, China
| | - Yan Li
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering, Shanghai Key Laboratory of Radiation Oncology, and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai, 200032, China
| | - Mo Wang
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering, Shanghai Key Laboratory of Radiation Oncology, and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai, 200032, China
| | - Aijun Liu
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering, Shanghai Key Laboratory of Radiation Oncology, and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai, 200032, China
| | - Zishuo Yu
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering, Shanghai Key Laboratory of Radiation Oncology, and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai, 200032, China
| | - Ke Chen
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering, Shanghai Key Laboratory of Radiation Oncology, and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai, 200032, China
| | - Dan Zhao
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering, Shanghai Key Laboratory of Radiation Oncology, and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai, 200032, China
| | - Yanhui Xu
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering, Shanghai Key Laboratory of Radiation Oncology, and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai, 200032, China.
- The International Co-laboratory of Medical Epigenetics and Metabolism, Ministry of Science and Technology, China, Department of Systems Biology for Medicine, School of Basic Medical Sciences, Shanghai Medical College of Fudan University, Shanghai, 200032, China.
- Human Phenome Institute, Collaborative Innovation Center of Genetics and Development, School of Life Sciences, Fudan University, Shanghai, 200433, China.
- State Key Laboratory of Reproductive Regulation and Breeding of Grassland Livestock School of Life Sciences, Inner Mongolia University, Hohhot, 010070, P. R. China.
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5
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Schuller M, Butler RE, Ariza A, Tromans-Coia C, Jankevicius G, Claridge TDW, Kendall SL, Goh S, Stewart GR, Ahel I. Molecular basis for DarT ADP-ribosylation of a DNA base. Nature 2021; 596:597-602. [PMID: 34408320 DOI: 10.1038/s41586-021-03825-4] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Accepted: 07/15/2021] [Indexed: 02/07/2023]
Abstract
ADP-ribosyltransferases use NAD+ to catalyse substrate ADP-ribosylation1, and thereby regulate cellular pathways or contribute to toxin-mediated pathogenicity of bacteria2-4. Reversible ADP-ribosylation has traditionally been considered a protein-specific modification5, but recent in vitro studies have suggested nucleic acids as targets6-9. Here we present evidence that specific, reversible ADP-ribosylation of DNA on thymidine bases occurs in cellulo through the DarT-DarG toxin-antitoxin system, which is found in a variety of bacteria (including global pathogens such as Mycobacterium tuberculosis, enteropathogenic Escherichia coli and Pseudomonas aeruginosa)10. We report the structure of DarT, which identifies this protein as a diverged member of the PARP family. We provide a set of high-resolution structures of this enzyme in ligand-free and pre- and post-reaction states, which reveals a specialized mechanism of catalysis that includes a key active-site arginine that extends the canonical ADP-ribosyltransferase toolkit. Comparison with PARP-HPF1, a well-established DNA repair protein ADP-ribosylation complex, offers insights into how the DarT class of ADP-ribosyltransferases evolved into specific DNA-modifying enzymes. Together, our structural and mechanistic data provide details of this PARP family member and contribute to a fundamental understanding of the ADP-ribosylation of nucleic acids. We also show that thymine-linked ADP-ribose DNA adducts reversed by DarG antitoxin (functioning as a noncanonical DNA repair factor) are used not only for targeted DNA damage to induce toxicity, but also as a signalling strategy for cellular processes. Using M. tuberculosis as an exemplar, we show that DarT-DarG regulates growth by ADP-ribosylation of DNA at the origin of chromosome replication.
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Affiliation(s)
- Marion Schuller
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
| | - Rachel E Butler
- Department of Microbial Sciences, School of Biosciences and Medicine, University of Surrey, Guildford, UK
| | - Antonio Ariza
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
| | | | - Gytis Jankevicius
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
- Biozentrum, University of Basel, Basel, Switzerland
| | - Tim D W Claridge
- Department of Chemistry, Chemistry Research Laboratory, University of Oxford, Oxford, UK
| | - Sharon L Kendall
- Centre for Emerging, Endemic and Exotic Disease, Pathology and Population Sciences, The Royal Veterinary College, Hatfield, UK
| | - Shan Goh
- Centre for Emerging, Endemic and Exotic Disease, Pathology and Population Sciences, The Royal Veterinary College, Hatfield, UK
| | - Graham R Stewart
- Department of Microbial Sciences, School of Biosciences and Medicine, University of Surrey, Guildford, UK.
| | - Ivan Ahel
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK.
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6
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Hellendahl KF, Kaspar F, Zhou X, Yang Z, Huang Z, Neubauer P, Kurreck A. Optimized Biocatalytic Synthesis of 2-Selenopyrimidine Nucleosides by Transglycosylation*. Chembiochem 2021; 22:2002-2009. [PMID: 33594780 PMCID: PMC8251958 DOI: 10.1002/cbic.202100067] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 02/16/2021] [Indexed: 01/09/2023]
Abstract
Selenium-modified nucleosides are powerful tools to study the structure and function of nucleic acids and their protein interactions. The widespread application of 2-selenopyrimidine nucleosides is currently limited by low yields in established synthetic routes. Herein, we describe the optimization of the synthesis of 2-Se-uridine and 2-Se-thymidine derivatives by thermostable nucleoside phosphorylases in transglycosylation reactions using natural uridine or thymidine as sugar donors. Reactions were performed at 60 or 80 °C and at pH 9 under hypoxic conditions to improve the solubility and stability of the 2-Se-nucleobases in aqueous media. To optimize the conversion, the reaction equilibria in analytical transglycosylation reactions were studied. The equilibrium constants of phosphorolysis of the 2-Se-pyrimidines were between 5 and 10, and therefore differ by an order of magnitude from the equilibrium constants of any other known case. Hence, the thermodynamic properties of the target nucleosides are inherently unfavorable, and this complicates their synthesis significantly. A tenfold excess of sugar donor was needed to achieve 40-48 % conversion to the target nucleoside. Scale-up of the optimized conditions provided four Se-containing nucleosides in 6-40 % isolated yield, which compares favorably to established chemical routes.
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Affiliation(s)
- Katja F. Hellendahl
- Technische Universität Berlin Faculty III Process Sciences, Institute of Biotechnology Chair of Bioprocess EngineeringAckerstraße 7613355BerlinGermany
| | - Felix Kaspar
- Technische Universität Berlin Faculty III Process Sciences, Institute of Biotechnology Chair of Bioprocess EngineeringAckerstraße 7613355BerlinGermany
- BioNukleo GmbHAckerstraße 7613355BerlinGermany
| | - Xinrui Zhou
- Sichuan University, College of Life Sciences Key Laboratory of Bio-Resource and Eco-Environment Ministry of EducationNo. 17 People's South Road Section 3610041ChengduP. R. China
| | - Zhaoyi Yang
- Sichuan University, College of Life Sciences Key Laboratory of Bio-Resource and Eco-Environment Ministry of EducationNo. 17 People's South Road Section 3610041ChengduP. R. China
| | - Zhen Huang
- Sichuan University, College of Life Sciences Key Laboratory of Bio-Resource and Eco-Environment Ministry of EducationNo. 17 People's South Road Section 3610041ChengduP. R. China
| | - Peter Neubauer
- Technische Universität Berlin Faculty III Process Sciences, Institute of Biotechnology Chair of Bioprocess EngineeringAckerstraße 7613355BerlinGermany
| | - Anke Kurreck
- Technische Universität Berlin Faculty III Process Sciences, Institute of Biotechnology Chair of Bioprocess EngineeringAckerstraße 7613355BerlinGermany
- BioNukleo GmbHAckerstraße 7613355BerlinGermany
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7
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Abstract
O2- and O4-alkylated thymidine lesions are known to be poorly repaired and persist in mammalian tissues. To understand how mammalian cells sense the presence and regulate the repair of these lesions, we employed a quantitative proteomic method to discover regioisomeric O2- and O4-n-butylthymidine (O2- and O4-nBudT)-binding proteins. We were able to identify 21 and 74 candidate DNA damage recognition proteins for O2-nBudT- and O4-nBudT-bearing DNA probes, respectively. Among these proteins, DDB1 and DDB2 selectively bind to O2-nBudT-containing DNA, whereas three high-mobility group (HMG) proteins (i.e., HMGB1, HMGB2, and mitochondrial transcription factor A (TFAM)) exhibit preferential binding to O4-nBudT-bearing DNA. We further demonstrated that TFAM binds directly and selectively with O4-alkyldT-harboring DNA, and the binding capacity depends mainly on the HMG box-A domain of TFAM. We also found that TFAM promotes transcriptional mutagenesis of O4-nBudT and O4-pyridyloxobutylthymidine, which is a DNA adduct induced by tobacco-specific N-nitrosamines, in vitro and in human cells. Together, we explored, for the first time, the interaction proteomes of O-alkyldT lesions, and our study expanded the functions of TFAM by revealing its capability in the recognition of O4-alkyldT-bearing DNA and uncovering its modulation of transcriptional mutagenesis of these lesions in human cells.
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Affiliation(s)
- Xiaomei He
- Department of Chemistry, University of California, Riverside, California 92521-0403, United States
| | - Pengcheng Wang
- Department of Chemistry, University of California, Riverside, California 92521-0403, United States
| | - Yinsheng Wang
- Department of Chemistry, University of California, Riverside, California 92521-0403, United States
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8
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Liguori A, Napoli A, Sindona G. Determination of substituent effects on the proton affinities of natural nucleosides by the kinetic method. J Mass Spectrom 2021; 56:e4677. [PMID: 33448524 DOI: 10.1002/jms.4677] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The kinetics of the unimolecular dissociations of proton-bound dimers produced by fast-atom bombardment from nucleosides and reference amines enables the evaluation of the proton affinities (PAs) of ribonucleosides. The PAs of cytosine, guanosine, adenosine, uridine, and deoxyuridine have been thus determined. These values and those already available for the corresponding DNA homologues allow the evaluation of the effect of the hydroxyl group in position 2' of the sugar moiety, which lowers the PAs of RNA nucleosides by 0.6-1 kcal/mol, and of the methyl group in position 5 of the thymine ring, which enhances the basicity of deoxythymidine over deoxyuridine by 0.6 kcal/mol.
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Affiliation(s)
- Angelo Liguori
- Department of Chemistry, University of Calabria, Arcavacata di Rende, Italy
| | - Anna Napoli
- Department of Chemistry, University of Calabria, Arcavacata di Rende, Italy
| | - Giovanni Sindona
- Department of Chemistry, University of Calabria, Arcavacata di Rende, Italy
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Müller S, Fritz Y, Wagenknecht H. Control of Energy Transfer Between Pyrene- and Perylene-Nucleosides by the Sequence of DNA-Templated Supramolecular Assemblies. ChemistryOpen 2020; 9:389-392. [PMID: 32257746 PMCID: PMC7110160 DOI: 10.1002/open.201900346] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Revised: 01/09/2020] [Indexed: 12/18/2022] Open
Abstract
DNA was used as supramolecular scaffold to order chromophores and control their optical properties. Ethynylpyrene as energy donor was attached to 2'-desoxy-2-aminoadenosine that binds selectively to thymidines (T) in the template. Ethynylperylene as acceptor was attached to 2'-desoxyuridine that is complementary to 2'-desoxyadenosine (A). This donor-acceptor pair was assembled along single-stranded DNA templates of different A-T sequences to investigate the sequence control of the energy transfer between the chromophores. The fluorescence intensities increase in the mixed assemblies along the DNA templates from A10T10 over (AATT)5 to (AT)10, although these templates provide equal numbers of potential binding sites for the two different nucleoside chromophore conjugates and exhibit similar absorbances. This shows that the sequence selective assembly of the two building blocks along DNA templates is programmable and alters the fluorescence readout. Such sequence-controlled supramolecular chemistry represents the key element for future functional π-systems in materials for light harvesting of solar energy.
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Affiliation(s)
- Sara Müller
- Institute of Organic ChemistryKarlsruhe Institute of Technology (KIT)Fritz-Haber-Weg 676131KarlsruheGermany
| | - Yannic Fritz
- Institute of Organic ChemistryKarlsruhe Institute of Technology (KIT)Fritz-Haber-Weg 676131KarlsruheGermany
| | - Hans‐Achim Wagenknecht
- Institute of Organic ChemistryKarlsruhe Institute of Technology (KIT)Fritz-Haber-Weg 676131KarlsruheGermany
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Cui Y, Yuan J, Wang P, Wu J, Yu Y, Wang Y. Collision-Induced Dissociation Studies of Protonated Ions of Alkylated Thymidine and 2'-Deoxyguanosine. J Am Soc Mass Spectrom 2020; 31:927-937. [PMID: 32134268 PMCID: PMC7362892 DOI: 10.1021/jasms.9b00147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Mass spectrometry and tandem MS (MS/MS) have been widely employed for the identification and quantification of damaged nucleosides in DNA, including those induced by alkylating agents. Upon collisional activation, protonated ions of alkylated nucleosides frequently undergo facile neutral loss of a 2-deoxyribose in MS/MS, and further cleavage of the resulting protonated nucleobases in MS3 can sometimes be employed for differentiating regioisomeric alkylated DNA lesions. Herein, we investigated systematically the collision-induced dissociation (CID) of the protonated ions of O4-alkylthymidine (O4-alkyldT), O2-alkyldT, O6-alkyl-2'-deoxyguanosine (O6-alkyldG), and N2-alkyldG through MS3 analysis. The MS3 of O2- and O4-MedT exhibit different fragmentation patterns from each other and from other O2- and O4-alkyldT adducts carrying larger alkyl groups. Meanwhile, elimination of alkene via a six-membered ring transition state is the dominant fragmentation pathway for O2-alkyldT, O4-alkyldT, and O6-alkyldG adducts carrying larger alkyl groups, whereas O6-MedG mainly undergoes elimination of ammonia. The breakdown of N2-alkyldG is substantially influenced by the structure of the alkyl group, where the relative ease in eliminating ammonia and alkene is modulated by the chain length and branching of the alkyl groups. We also rationalize our observations with density functional theory (DFT) calculations.
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Heib A, Niro G, Weck SC, Koppermann S, Ducho C. Muraymycin Nucleoside Antibiotics: Structure-Activity Relationship for Variations in the Nucleoside Unit. Molecules 2019; 25:molecules25010022. [PMID: 31861655 PMCID: PMC6983020 DOI: 10.3390/molecules25010022] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Revised: 12/10/2019] [Accepted: 12/12/2019] [Indexed: 12/04/2022] Open
Abstract
Muraymycins are a subclass of naturally occurring nucleoside antibiotics with promising antibacterial activity. They inhibit the bacterial enzyme translocase I (MraY), a clinically yet unexploited target mediating an essential intracellular step of bacterial peptidoglycan biosynthesis. Several structurally simplified muraymycin analogues have already been synthesized for structure–activity relationship (SAR) studies. We now report on novel derivatives with unprecedented variations in the nucleoside unit. For the synthesis of these new muraymycin analogues, we employed a bipartite approach facilitating the introduction of different nucleosyl amino acid motifs. This also included thymidine- and 5-fluorouridine-derived nucleoside core structures. Using an in vitro assay for MraY activity, it was found that the introduction of substituents in the 5-position of the pyrimidine nucleobase led to a significant loss of inhibitory activity towards MraY. The loss of nucleobase aromaticity (by reduction of the uracil C5-C6 double bond) resulted in a ca. tenfold decrease in inhibitory potency. In contrast, removal of the 2′-hydroxy group furnished retained activity, thus demonstrating that modifications of the ribose moiety might be well-tolerated. Overall, these new SAR insights will guide the future design of novel muraymycin analogues for their potential development towards antibacterial drug candidates.
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12
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Ming F, Hou J, Hou C, Yang M, Wang X, Li J, Huo D, He Q. One-step synthesized fluorescent nitrogen doped carbon dots from thymidine for Cr (VI) detection in water. Spectrochim Acta A Mol Biomol Spectrosc 2019; 222:117165. [PMID: 31185440 DOI: 10.1016/j.saa.2019.117165] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Revised: 05/23/2019] [Accepted: 05/26/2019] [Indexed: 05/27/2023]
Abstract
A novel, simple and low-cost nitrogen doped carbon dots (N-CDs) fluorescent sensor for sensitive detection of Cr (VI) was developed via one-step hydrothermal method using thymidine as carbon source. As-prepared N-CDs exhibited the ability of sensitive and selective detection of Cr (VI) through the inner filter effect (IFE). The performances of N-CDs were investigated with the characterization methods of transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Under the optimized conditions, a good logarithm correlation between the fluorescence intensity of N-CDS and the concentration of Cr (VI) was obtained ranging from 0.1 μM to 430 μM (R2 = 0.992), with a low detection limit (LOD; S/N = 3) of 1.26 nM. The fluorescent sensor showed good repeatability, reproducibility and stability. Furthermore, N-CDs fluorescent sensor had a good applicability for Cr (VI) detection in real water samples with acceptable recoveries, and the detection results were consistent with the inductively coupled plasma mass spectrometry (ICP-MS) results, indicating this fluorescent sensor has a great potential for the environmental monitoring.
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Affiliation(s)
- Fanglin Ming
- Key Laboratory for Biorheological Science and Technology of Ministry of Education, State and Local Joint Engineering Laboratory for Vascular Implants, Bioengineering College of Chongqing University, Chongqing 400044, PR China
| | - Jingzhou Hou
- Key Laboratory of Eco-Environment of Three Gorges Region of Ministry of Education, Faculty of Urban Construction and Environmental Engineering, Chongqing University, Chongqing 400045, PR China
| | - Changjun Hou
- Key Laboratory for Biorheological Science and Technology of Ministry of Education, State and Local Joint Engineering Laboratory for Vascular Implants, Bioengineering College of Chongqing University, Chongqing 400044, PR China.
| | - Mei Yang
- Key Laboratory for Biorheological Science and Technology of Ministry of Education, State and Local Joint Engineering Laboratory for Vascular Implants, Bioengineering College of Chongqing University, Chongqing 400044, PR China
| | - Xianfeng Wang
- Key Laboratory for Biorheological Science and Technology of Ministry of Education, State and Local Joint Engineering Laboratory for Vascular Implants, Bioengineering College of Chongqing University, Chongqing 400044, PR China
| | - Jiawei Li
- Key Laboratory for Biorheological Science and Technology of Ministry of Education, State and Local Joint Engineering Laboratory for Vascular Implants, Bioengineering College of Chongqing University, Chongqing 400044, PR China
| | - Danqun Huo
- Key Laboratory for Biorheological Science and Technology of Ministry of Education, State and Local Joint Engineering Laboratory for Vascular Implants, Bioengineering College of Chongqing University, Chongqing 400044, PR China
| | - Qiang He
- Key Laboratory of Eco-Environment of Three Gorges Region of Ministry of Education, Faculty of Urban Construction and Environmental Engineering, Chongqing University, Chongqing 400045, PR China.
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13
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Galegov GA, Andronova VL. [AntiHIV/AIDS drug 6HP: antiviral activity, pre-clinical study. Efficiency in adult HIV-infected patients.]. Vopr Virusol 2019; 64:12-15. [PMID: 30893524 DOI: 10.18821/0507-4088-2019-64-1-12-15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Accepted: 04/26/2018] [Indexed: 06/09/2023]
Abstract
The new domestic antiretroviral drug 6HP, which is ammonium-3'-azido-3'-deoxythymidine-5'-carbomoylphosphonate, shows a high level of anti-HIV activity in cultures of lymphoblastoid cells. In a organism, the 6HP is converted to azidothymidine, and the its pharmacokinetic parameters indicate a prolonged nature of action of this compound in vivo. It is an important indicator that allows to formulate optimal therapeutic regimens during clinical application of 6HP. The complex of its antiviral properties and the results of its exhaustive preclinica study, as well as the results of studying its safety and tolerability in adult HIV-infected patients, including important first data of its use as a specific therapeutic antiHIV / AIDS drug, certainly indicate on its prospects and its usefulness in clinical use in patients with HIV infection, including as part of combination antiretroviral therapy.
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Affiliation(s)
- G A Galegov
- National Research Centre for Epidemiology and Microbiology named after the honorary academician N.F. Gamaleya, 123098, Moscow, Russian Federation
| | - V L Andronova
- National Research Centre for Epidemiology and Microbiology named after the honorary academician N.F. Gamaleya, 123098, Moscow, Russian Federation
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14
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Abstract
A wide spectrum of DNA lesions can be generated from byproducts of endogenous metabolism and/or from environmental exposure. A DNA adductomic approach for the robust quantification of DNA adducts in cellular and tissue DNA may facilitate the use of DNA adducts for biomonitoring studies and enable comprehensive assessment about DNA repair. Normalized retention time (iRT) has been widely used in scheduled selected-reaction monitoring (SRM) methods for highly sensitive and high-throughput analyses of protein samples in complicated matrices. By using a similar method, we established the iRT scores for 36 modified nucleosides from the retention times of the four canonical 2'-deoxynucleosides on a nanoflow liquid chromatography-nanospray ionization-tandem mass spectrometry (nLC-NSI-MS/MS) system. The iRT scores facilitated reliable prediction of retention time and were employed for establishing a scheduled SRM method for quantitative assessment of a subset of the DNA adductome. The quantification results of the scheduled SRM method were more accurate and precise than those from an unscheduled method.
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Affiliation(s)
- Yuxiang Cui
- Environmental Toxicology Graduate Program, University of California, Riverside, California 92521, United States
| | - Pengcheng Wang
- Department of Chemistry, University of California, Riverside, California 92521, United States
| | - Yang Yu
- Environmental Toxicology Graduate Program, University of California, Riverside, California 92521, United States
| | - Jun Yuan
- Environmental Toxicology Graduate Program, University of California, Riverside, California 92521, United States
| | - Yinsheng Wang
- Environmental Toxicology Graduate Program, University of California, Riverside, California 92521, United States
- Department of Chemistry, University of California, Riverside, California 92521, United States
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15
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Gérard-Hirne T, Thiebaut F, Sachon E, Désert A, Drujon T, Guérineau V, Michel BY, Benhida R, Coulon S, Saintomé C, Guianvarc'h D. Photoactivatable oligonucleotide probes to trap single-stranded DNA binding proteins: Updating the potential of 4-thiothymidine from a comparative study. Biochimie 2018; 154:164-175. [PMID: 30171884 DOI: 10.1016/j.biochi.2018.08.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Accepted: 08/27/2018] [Indexed: 02/07/2023]
Abstract
Photoaffinity labeling (PAL) in combination with recent developments in mass spectrometry is a powerful tool for studying nucleic acid-protein interactions, enabling crosslinking of both partners through covalent bond formation. Such a strategy requires a preliminary study of the most judicious photoreactive group to crosslink efficiently with the target protein. In this study, we report a survey of three different photoreactive nucleobases (including a guanine functionalized with a benzophenone or a diazirine and the zero-length agent 4-thiothymine) incorporated in 30-mer oligonucleotides (ODN) containing a biotin moiety for selective trapping and enrichment of single-stranded DNA binding proteins (SSB). First, the conditions and efficiency of the photochemical reaction with a purified protein using human replication protein A as the relevant model was studied. Secondly, the ability of the probe as bait to photocrosslink and enrich SSB in cell lysate was addressed. Among the different ODN probes studied, we showed that 4-thiothymine was the most relevant: i) it allows efficient and specific trapping of SSB in whole cell extracts in a similar extent as the widely used diazirine, ii) it features the advantages of a zero-length agent thus retaining the physicochemical properties of the ODN bait; iii) ODN including this photochemical agent are easily accessible. In combination with mass spectrometry, the probes incorporating this nucleobase are powerful tools for PAL strategies and can be added in the toolbox of the traditional photocrosslinkers for studying DNA-protein interactions.
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Affiliation(s)
- Tom Gérard-Hirne
- Sorbonne Université, École normale supérieure, PSL University, CNRS, Laboratoire des biomolécules, LBM, 75005 Paris, France
| | - Frédéric Thiebaut
- Sorbonne Université, École normale supérieure, PSL University, CNRS, Laboratoire des biomolécules, LBM, 75005 Paris, France; MNHN CNRS UMR 7196, INSERM U1154, 43 Rue Cuvier, 75005, Paris, France
| | - Emmanuelle Sachon
- Sorbonne Université, École normale supérieure, PSL University, CNRS, Laboratoire des biomolécules, LBM, 75005 Paris, France; Plateforme de spectrométrie de masse et protéomique, IBPS, FR3631, UPMC, 4 Place Jussieu, 75005, Paris, France
| | - Alexandre Désert
- Sorbonne Université, École normale supérieure, PSL University, CNRS, Laboratoire des biomolécules, LBM, 75005 Paris, France
| | - Thierry Drujon
- Sorbonne Université, École normale supérieure, PSL University, CNRS, Laboratoire des biomolécules, LBM, 75005 Paris, France
| | - Vincent Guérineau
- Institut de Chimie des Substances Naturelles, CNRS UPR2301, Université Paris-Sud, Université Paris-Saclay, Avenue de la Terrasse, 91198, Gif-sur-Yvette Cedex, France
| | - Benoît Y Michel
- Université Côte d'Azur, CNRS, Institut de Chimie de Nice UMR 7272, 06108 Nice, France
| | - Rachid Benhida
- Université Côte d'Azur, CNRS, Institut de Chimie de Nice UMR 7272, 06108 Nice, France
| | - Stéphane Coulon
- CRCM, CNRS, Inserm, Aix-Marseille Univ, Institut Paoli-Calmettes, Equipe Labellisée Ligue, Marseille, France
| | - Carole Saintomé
- MNHN CNRS UMR 7196, INSERM U1154, 43 Rue Cuvier, 75005, Paris, France; Sorbonne Université, UFR927, 4, Place Jussieu, F-75005, Paris, France.
| | - Dominique Guianvarc'h
- Sorbonne Université, École normale supérieure, PSL University, CNRS, Laboratoire des biomolécules, LBM, 75005 Paris, France; Institut de Chimie Moléculaire et des Matériaux d'Orsay, Univ. Paris-Sud, CNRS, Université Paris-Saclay, F-91405, Orsay, France.
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16
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Schmidt OP, Benz AS, Mata G, Luedtke NW. HgII binds to C-T mismatches with high affinity. Nucleic Acids Res 2018; 46:6470-6479. [PMID: 29901748 PMCID: PMC6061796 DOI: 10.1093/nar/gky499] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Revised: 05/04/2018] [Accepted: 06/11/2018] [Indexed: 02/07/2023] Open
Abstract
Binding reactions of HgII and AgI to pyrimidine-pyrimidine mismatches in duplex DNA were characterized using fluorescent nucleobase analogs, thermal denaturation and 1H NMR. Unlike AgI, HgII exhibited stoichiometric, site-specific binding of C-T mismatches. The on- and off-rates of HgII binding were approximately 10-fold faster to C-T mismatches (kon ≈ 105 M-1 s-1, koff ≈ 10-3 s-1) as compared to T-T mismatches (kon ≈ 104 M-1 s-1, koff ≈ 10-4 s-1), resulting in very similar equilibrium binding affinities for both types of 'all natural' metallo base pairs (Kd ≈ 10-150 nM). These results are in contrast to thermal denaturation analyses, where duplexes containing T-T mismatches exhibited much larger increases in thermal stability upon addition of HgII (ΔTm = 6-19°C), as compared to those containing C-T mismatches (ΔTm = 1-4°C). In addition to revealing the high thermodynamic and kinetic stabilities of C-HgII-T base pairs, our results demonstrate that fluorescent nucleobase analogs enable highly sensitive detection and characterization of metal-mediated base pairs - even in situations where metal binding has little or no impact on the thermal stability of the duplex.
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Affiliation(s)
- Olivia P Schmidt
- University of Zurich, Department of Chemistry, Zurich, Switzerland
| | - Andrea S Benz
- University of Zurich, Department of Chemistry, Zurich, Switzerland
| | - Guillaume Mata
- University of Zurich, Department of Chemistry, Zurich, Switzerland
| | - Nathan W Luedtke
- University of Zurich, Department of Chemistry, Zurich, Switzerland
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17
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Novosjolova I, Kennedy SD, Rozners E. 2-Methoxypyridine as a Thymidine Mimic in Watson-Crick Base Pairs of DNA and PNA: Synthesis, Thermal Stability, and NMR Structural Studies. Chembiochem 2017; 18:2165-2170. [PMID: 28858428 PMCID: PMC5920655 DOI: 10.1002/cbic.201700400] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Indexed: 12/21/2022]
Abstract
The development of nucleic acid base-pair analogues that use new modes of molecular recognition is important both for fundamental research and practical applications. The goal of this study was to evaluate 2-methoxypyridine as a cationic thymidine mimic in the A-T base pair. The hypothesis was that including protonation in the Watson-Crick base pairing scheme would enhance the thermal stability of the DNA double helix without compromising the sequence selectivity. DNA and peptide nucleic acid (PNA) sequences containing the new 2-methoxypyridine nucleobase (P) were synthesized and studied by using UV thermal melting and NMR spectroscopy. Introduction of P nucleobase caused a loss of thermal stability of ≈10 °C in DNA-DNA duplexes and ≈20 °C in PNA-DNA duplexes over a range of mildly acidic to neutral pH. Despite the decrease in thermal stability, the NMR structural studies showed that P-A formed the expected protonated base pair at pH 4.3. Our study demonstrates the feasibility of cationic unnatural base pairs; however, future optimization of such analogues will be required.
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Affiliation(s)
- Irina Novosjolova
- Department of Chemistry, Binghamton University, The State University of New York, Binghamton, NY, 13902, USA
| | - Scott D Kennedy
- Department of Biochemistry and Biophysics, University of Rochester School of Medicine and Dentistry, Rochester, NY, 14642, USA
| | - Eriks Rozners
- Department of Chemistry, Binghamton University, The State University of New York, Binghamton, NY, 13902, USA
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18
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Rapic S, Vangestel C, Verhaeghe J, Thomae D, Pauwels P, Van den Wyngaert T, Staelens S, Stroobants S. Evaluation of [ 18F]Fluorothymidine as a Biomarker for Early Therapy Response in a Mouse Model of Colorectal Cancer. Mol Imaging Biol 2017; 19:109-119. [PMID: 27324368 DOI: 10.1007/s11307-016-0974-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
PURPOSE In oncology, positron emission tomography imaging using dedicated tracers as biomarkers may assist in early evaluation of therapy efficacy. Using 3'-deoxy-3'-[18F]fluorothymidine ([18F]FLT), we investigated the early effects of chemotherapeutic treatment on cancer cell proliferation in a BRAF-mutated colorectal cancer xenograft model. PROCEDURES Colo205 subcutaneously inoculated animals underwent 90-min dynamic imaging before and 24 h after treatment with vehicle (control), cetuximab (resistant) or irinotecan (sensitive). Total distribution volume was quantified from dynamic data, and standardized uptake values as well as tumor-to-blood ratios were calculated from static images averaged over the last 20 min. In vivo imaging data was correlated with ex vivo proliferation and thymidine metabolism proteins. RESULTS All imaging parameters showed a significant post-treatment decrease from [18F]FLT baseline uptake for the irinotecan group (p ≤ 0.001) as compared with the cetuximab and vehicle group and correlated strongly with each other (p ≤ 0.0001). In vivo data were in agreement with Ki67 staining, showing a significantly lower percentage of Ki67-positive cells in the irinotecan group as compared with other groups (p ≤ 0.0001). Tumor expression of thymidine kinase 1 phosphorylated on serine 13, thymidylate synthase, and thymidine phosphorylase remained unaffected, while thymidine kinase 1 expression was, surprisingly, significantly higher in irinotecan-treated animals (p ≤ 0.01). In contrast, tumor ATP levels were lowest in this group. CONCLUSIONS [18F]FLT positron emission tomography was found to be a suitable biomarker of early tumor response to anti-proliferative treatment, with static imaging not being inferior to full compartmental analysis in our xenograft model. The dynamics of thymidine kinase 1 protein expression and protein activity in low ATP environments merits further investigation.
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Affiliation(s)
- Sara Rapic
- Molecular Imaging Center Antwerp (MICA), Faculty of Medicine and Health Sciences, University of Antwerp, Universiteitsplein 1, 2610, Wilrijk, Belgium
| | - Christel Vangestel
- Molecular Imaging Center Antwerp (MICA), Faculty of Medicine and Health Sciences, University of Antwerp, Universiteitsplein 1, 2610, Wilrijk, Belgium
- Department of Nuclear Medicine, Antwerp University Hospital, Wilrijkstraat 10, 2650, Edegem, Belgium
| | - Jeroen Verhaeghe
- Molecular Imaging Center Antwerp (MICA), Faculty of Medicine and Health Sciences, University of Antwerp, Universiteitsplein 1, 2610, Wilrijk, Belgium
| | - David Thomae
- Molecular Imaging Center Antwerp (MICA), Faculty of Medicine and Health Sciences, University of Antwerp, Universiteitsplein 1, 2610, Wilrijk, Belgium
- Department of Nuclear Medicine, Antwerp University Hospital, Wilrijkstraat 10, 2650, Edegem, Belgium
| | - Patrick Pauwels
- Center for Oncological Research (CORE), University of Antwerp, Universiteitsplein 1, 2610, Wilrijk, Belgium
- Department of Pathology, Antwerp University Hospital, Wilrijkstraat 10, 2650, Edegem, Belgium
| | - Tim Van den Wyngaert
- Molecular Imaging Center Antwerp (MICA), Faculty of Medicine and Health Sciences, University of Antwerp, Universiteitsplein 1, 2610, Wilrijk, Belgium
- Department of Nuclear Medicine, Antwerp University Hospital, Wilrijkstraat 10, 2650, Edegem, Belgium
| | - Steven Staelens
- Molecular Imaging Center Antwerp (MICA), Faculty of Medicine and Health Sciences, University of Antwerp, Universiteitsplein 1, 2610, Wilrijk, Belgium
| | - Sigrid Stroobants
- Molecular Imaging Center Antwerp (MICA), Faculty of Medicine and Health Sciences, University of Antwerp, Universiteitsplein 1, 2610, Wilrijk, Belgium.
- Department of Nuclear Medicine, Antwerp University Hospital, Wilrijkstraat 10, 2650, Edegem, Belgium.
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19
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Bedi MF, Li W, Gutwald T, Bryant-Friedrich AC. Synthesis of damaged DNA containing the oxidative lesion 3'-oxothymidine. Bioorg Med Chem 2017; 25:5598-5602. [PMID: 28927804 DOI: 10.1016/j.bmc.2017.08.032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Revised: 08/16/2017] [Accepted: 08/18/2017] [Indexed: 11/16/2022]
Abstract
Oxidative events that take place during regular oxygen metabolism can lead to the formation of organic or inorganic radicals. The interaction of these radicals with macromolecules in the organism and with DNA in particular is suspected to lead to apoptosis, DNA lesions and cell damage. Independent generation of DNA lesions resulting from oxidative damage is used to promote the study of their effects on biological systems. An efficient synthesis of oligodeoxyribonucleotides (ODNs) containing the oxidative damage lesion 3'-oxothymidine has been accomplished via incorporation of C3'-hydroxymethyl thymidine as its corresponding 5'-phosphoramidite. Through oxidative cleavage using sodium periodate in aqueous solution, the lesion of interest is easily generated. Due to its inherent instability it cannot be directly isolated, but must be generated in situ. 3'-Oxothymidine is a demonstrated damage product formed upon generation of the C3'-thymidinyl radical in ODN.
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Affiliation(s)
- Mel F Bedi
- Department of Medicinal and Biological Chemistry, College of Pharmacy and Pharmaceutical Sciences, The University of Toledo, 2801 W. Bancroft St., Toledo, OH, United States
| | - Weiye Li
- Department of Medicinal Chemistry and Pharmacognosy, The University of Illinois Chicago, 1601 Parkview Ave. Rm A301, Rockford, IL 61107, United States
| | - Taylor Gutwald
- Chicago College of Pharmacy, Midwestern University, Chicago, 555 31st Street, Downers Grove, IL 60515, United States
| | - Amanda C Bryant-Friedrich
- Department of Medicinal and Biological Chemistry, College of Pharmacy and Pharmaceutical Sciences, The University of Toledo, 2801 W. Bancroft St., Toledo, OH, United States.
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20
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Wang R, Jin C, Zhu X, Zhou L, Xuan W, Liu Y, Liu Q, Tan W. Artificial Base zT as Functional "Element" for Constructing Photoresponsive DNA Nanomolecules. J Am Chem Soc 2017; 139:9104-9107. [PMID: 28585836 PMCID: PMC5877792 DOI: 10.1021/jacs.7b02865] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
In contrast to small molecules, DNA and RNA macromolecules can be accurately formulated with base "elements" abbreviated as A, T, U, C, and G. However, the development of functionally artificial bases can result in the generation of new biomaterials with unique properties and applications. Therefore, we herein report the design and synthesis of a photoresponsive base as a new functional or molecular "element" for constructing DNA nanomolecules. The new base is made by fusion of an azobenzene with a natural T base (zT). zT, a new molecular element, is not only the most size-expanded T analogue but also a photoresponsive base capable of specific self-assembly through hydrogen bonding. Our results showed that stable and selective self-assembly of double-stranded DNAs occurred through zT-A base pairing, but it could still be efficiently dissociated by light irradiation. The photoresponsive DNA bases will provide the versatility required for constructing desired DNA nanomolecules and nanodevices.
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Affiliation(s)
- Ruowen Wang
- Molecular Sciences and Biomedicine Laboratory, State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering and College of Life Sciences, Aptamer Engineering Center of Hunan Province, Hunan University, Changsha, Hunan 410082, China
- Departments of Chemistry and Department of Physiology and Functional Genomics, Center for Research at the Bio/Nano Interface, University Health Cancer Center, UF Genetics Institute and McKnight Brain Institute, University of Florida, Gainesville, Florida 32611-7200, United States
| | - Cheng Jin
- Molecular Sciences and Biomedicine Laboratory, State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering and College of Life Sciences, Aptamer Engineering Center of Hunan Province, Hunan University, Changsha, Hunan 410082, China
| | - Xiaoyan Zhu
- Molecular Sciences and Biomedicine Laboratory, State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering and College of Life Sciences, Aptamer Engineering Center of Hunan Province, Hunan University, Changsha, Hunan 410082, China
| | - Liyi Zhou
- Molecular Sciences and Biomedicine Laboratory, State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering and College of Life Sciences, Aptamer Engineering Center of Hunan Province, Hunan University, Changsha, Hunan 410082, China
| | - Wenjing Xuan
- Molecular Sciences and Biomedicine Laboratory, State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering and College of Life Sciences, Aptamer Engineering Center of Hunan Province, Hunan University, Changsha, Hunan 410082, China
| | - Yuan Liu
- Molecular Sciences and Biomedicine Laboratory, State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering and College of Life Sciences, Aptamer Engineering Center of Hunan Province, Hunan University, Changsha, Hunan 410082, China
- Departments of Chemistry and Department of Physiology and Functional Genomics, Center for Research at the Bio/Nano Interface, University Health Cancer Center, UF Genetics Institute and McKnight Brain Institute, University of Florida, Gainesville, Florida 32611-7200, United States
| | - Qiaoling Liu
- Molecular Sciences and Biomedicine Laboratory, State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering and College of Life Sciences, Aptamer Engineering Center of Hunan Province, Hunan University, Changsha, Hunan 410082, China
- Departments of Chemistry and Department of Physiology and Functional Genomics, Center for Research at the Bio/Nano Interface, University Health Cancer Center, UF Genetics Institute and McKnight Brain Institute, University of Florida, Gainesville, Florida 32611-7200, United States
| | - Weihong Tan
- Molecular Sciences and Biomedicine Laboratory, State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering and College of Life Sciences, Aptamer Engineering Center of Hunan Province, Hunan University, Changsha, Hunan 410082, China
- Departments of Chemistry and Department of Physiology and Functional Genomics, Center for Research at the Bio/Nano Interface, University Health Cancer Center, UF Genetics Institute and McKnight Brain Institute, University of Florida, Gainesville, Florida 32611-7200, United States
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21
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Tsao YY, Wooley KL. Synthetic, Functional Thymidine-Derived Polydeoxyribonucleotide Analogues from a Six-Membered Cyclic Phosphoester. J Am Chem Soc 2017; 139:5467-5473. [PMID: 28394136 PMCID: PMC5451148 DOI: 10.1021/jacs.7b01116] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Indexed: 12/24/2022]
Abstract
A grand challenge that crosses synthetic chemistry and biology is the scalable production of functional analogues of biomacromolecules. We have focused our attention on the use of deoxynucleoside building blocks bearing non-natural bases to develop a synthetic methodology that allows for the construction of high molecular weight deoxynucleotide polymers. Our six-membered cyclic phosphoester ring-opening polymerization strategy is demonstrated, herein, by an initial preparation of novel polyphosphoesters, comprised of butenyl-functionalized deoxyribonucleoside repeat units, connected via 3',5'-backbone linkages. A thymidine-derived bicyclic monomer, 3',5'-cyclic 3-(3-butenyl) thymidine ethylphosphate, was synthesized in two steps directly from thymidine, via butenylation and diastereoselective cyclization promoted by N,N-dimethyl-4-aminopyridine. Computational modeling of the six-membered 3',5'-cyclic phosphoester ring derived from deoxyribose indicated strain energies at least 5.4 kcal/mol higher than those of the six-membered monocyclic phosphoester, 2-ethoxy-1,3,2-dioxaphosphinane 2-oxide. These calculations supported the hypothesis that the strained 3',5'-cyclic monomer can promote ring-opening polymerization to afford the resulting poly(3',5'-cyclic 3-(3-butenyl) thymidine ethylphosphate)s with low dispersities (Đ < 1.10). This advanced design combines the merits of natural product-derived materials and functional, degradable polymers to provide a new platform for functional, synthetically derived polydeoxyribonucleotide-analogue materials.
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Affiliation(s)
- Yi-Yun
Timothy Tsao
- Departments of Chemistry,
Chemical Engineering, Materials Science & Engineering, and The
Laboratory for Synthetic-Biologic Interactions, Texas A&M University, College Station, Texas 77842-3012, United States
| | - Karen L. Wooley
- Departments of Chemistry,
Chemical Engineering, Materials Science & Engineering, and The
Laboratory for Synthetic-Biologic Interactions, Texas A&M University, College Station, Texas 77842-3012, United States
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22
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Balzarini J, Celen S, Karlsson A, de Groot T, Verbruggen A, Bormans G. The Effect of a Methyl or 2-fluoroethyl Substituent at the N-3 Position of Thymidine, 3′-fluoro-3′-deoxythymi-dine and 1-β-D-arabinosylthymine on Their Antiviral and Cytostatic Activity in Cell Culture. ACTA ACUST UNITED AC 2016; 17:17-23. [PMID: 16542002 DOI: 10.1177/095632020601700103] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Thymidine (Thd), 1-β-D-arabinosylthymine (ara-T) and 3′-fluoro-3′-deoxythymidine (FLT) have been substituted at N-3 by a methyl or a 2-fluoroethyl group. FLT and ara-T are markedly inhibitory against human immunodeficiency virus type 1 (HIV-1) and HIV-2, and herpes simplex virus type 1 (HSV-1) and HSV-2, respectively. Modification at N-3 of these compounds markedly decreases both the antiviral and cytostatic activity of the parent compounds FLT and ara-T except for N-3-(methyl)-Thd that proved highly cytostatic for murine leukaemia L1210 cells. The decreased biological activity of the N-3-substituted pyrimidine nucleo-side analogues coincides with a significantly lower affinity of the modified Thd analogues for the cellular and viral (activating) nucleoside kinases.
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Affiliation(s)
- Jan Balzarini
- Rega Institute for Medical Research, K.U. Leuven, Leuven, Belgium.
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23
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Abstract
The combination of different anti-HIV agents has become the standard of care for AIDS or HIV-infected individuals. Important progress has been made in the development of drugs for the clinical treatment of HIV infection. To date, 20 drugs have been approved for the treatment of AIDS. However, viral rebound during therapy, the emergence of HIV drug resistance and the need for long-term treatment modalities are the main causes for the failure of current antiretroviral therapy. There is still a need for the development of new drugs that are either less toxic, active against the growing number of drug-resistant HIV strains or directed to novel targets in the viral life cycle. Eleven of the approved anti-HIV drugs target the reverse transcriptase (RT). Among the so-called non-nucleoside RT inhibitors (NNRTIs) TSAO derivatives are an unusual class of compounds that exert their unique selectivity for HIV-1 through a specific interaction with the p51 subunit of HIV-1 RT. They are the only NNRTIs for which amino acids at both subunits (p66 and p51) of HIV-1 RT are needed for optimal interaction with the enzyme. Moreover, the TSAO compounds are the first non-peptide molecules that interfere with the dimerization of the enzyme.
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Schmied-Tobies MIH, Paschke H, Reemtsma T. Combined chemoassay and mass spectrometric approach to study the reactive potential of electrophiles towards deoxynucleosides as model for DNA. Chemosphere 2016; 151:263-270. [PMID: 26945242 DOI: 10.1016/j.chemosphere.2016.02.052] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Revised: 02/10/2016] [Accepted: 02/11/2016] [Indexed: 06/05/2023]
Abstract
The modification of DNA by adduct formation is a potential molecular initiating event of genotoxicity. A chemoassay was established to study adduct formation of electrophiles with deoxynucleosides. Liquid chromatography-mass spectrometry was used to determine the reactivity of the model electrophiles para-benzoquinone, hydroquinone, and 1,4-naphthoquinone with deoxynucleoside (deoxyadenosine (dA), deoxyguanosine (dG), deoxycytidine (dC) and thymidine (dT)) to detect formation of adducts via constant neutral loss scan of deoxyribose (116 Da), and to elucidate adduct structures using high resolution mass spectrometry. Of the four deoxynucleosides dG was most susceptible, followed by dC and para-benzoquinone was the most reactive electrophile. With this approach five dG and four dC adducts were detected, formed by Michael addition and subsequent condensation. Also oxidation occurred with reactive oxygen species (ROS). Three of the adducts formed by benzoquinone have not been reported before. This chemoassay combined with mass spectrometry offers a way (a) to screen a large number of chemicals for their genotoxic potential, (b) to determine novel adducts that may be searched for in in vitro and in vivo studies and thus (c) to better understand the reaction of electrophiles with nucleobases.
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Affiliation(s)
| | - Heidrun Paschke
- Helmholtz Centre for Environmental Research - UFZ, Permoserstrasse 15, 04318 Leipzig, Germany
| | - Thorsten Reemtsma
- Helmholtz Centre for Environmental Research - UFZ, Permoserstrasse 15, 04318 Leipzig, Germany.
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25
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Wu RR, Yang B, Frieler CE, Berden G, Oomens J, Rodgers MT. 2,4-Dihydroxy and O2 Protonated Tautomers of dThd and Thd Coexist in the Gas Phase: Methylation Alters Protonation Preferences versus dUrd and Urd. J Am Soc Mass Spectrom 2016; 27:410-421. [PMID: 26676730 DOI: 10.1007/s13361-015-1303-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Revised: 10/25/2015] [Accepted: 10/28/2015] [Indexed: 06/05/2023]
Abstract
The gas-phase structures of protonated thymidine, [dThd + H](+), and its modified form, protonated 5-methyluridine, [Thd + H](+), are examined by infrared multiple photon dissociation (IRMPD) action spectroscopy combined with electronic structure calculations. IRMPD action spectra are measured over the ranges extending from ~600 to 1900 cm(-1) and ~2800 to 3800 cm(-1) using the FELIX free electron laser and an optical parametric oscillator/amplifier (OPO/OPA) laser system, respectively. Comparisons between the B3LYP/6-311+G(d,p) linear IR spectra calculated for the stable low-energy conformers and the measured IRMPD spectra are used to determine the most favorable tautomeric conformations of [dThd + H](+) and [Thd + H](+) and to identify those populated in the experiments. Both B3LYP and MP2 levels of theory predict a minor 2,4-dihydroxy tautomer as the ground-state conformer of [dThd + H](+) and [Thd + H](+) indicating that the 2'-hydroxyl substituent of Thd does not exert a significant impact on the structural features. [dThd + H](+) and [Thd + H](+) share parallel IRMPD spectral profiles and yields in both the FELIX and OPO regions. Comparisons between the measured IRMPD and calculated IR spectra suggest that minor 2,4-dihydroxy tautomers and O2 protonated conformers of [dThd + H](+) and [Thd + H](+) are populated in the experiments. Comparison of this work to our previous IRMPD spectroscopy study of protonated 2'-deoxyuridine and uridine suggests that the 5-methyl substituent alters the preferences of O2 versus O4 protonation.
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Affiliation(s)
- R R Wu
- Department of Chemistry, Wayne State University, Detroit, MI, 48202, USA
| | - Bo Yang
- Department of Chemistry, Wayne State University, Detroit, MI, 48202, USA
| | - C E Frieler
- Department of Chemistry, Wayne State University, Detroit, MI, 48202, USA
| | - G Berden
- FELIX Laboratory, Institute for Molecules and Materials, Radboud University, Toernooiveld 7, 6525 ED, Nijmegen, The Netherlands
| | - J Oomens
- FELIX Laboratory, Institute for Molecules and Materials, Radboud University, Toernooiveld 7, 6525 ED, Nijmegen, The Netherlands
- van't Hoff Institute for Molecular Sciences, University of Amsterdam, 1090 GD, Amsterdam, The Netherlands
| | - M T Rodgers
- Department of Chemistry, Wayne State University, Detroit, MI, 48202, USA.
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26
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Kim SK, Castro A, Kim ES, Dinkel AP, Liu X, Castro M. Inhibitory Effect of Bridged Nucleosides on Thermus aquaticus DNA Polymerase and Insight into the Binding Interactions. PLoS One 2016; 11:e0147234. [PMID: 26820310 PMCID: PMC4731470 DOI: 10.1371/journal.pone.0147234] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2015] [Accepted: 12/30/2015] [Indexed: 11/25/2022] Open
Abstract
Modified nucleosides have the potential to inhibit DNA polymerases for the treatment of viral infections and cancer. With the hope of developing potent drug candidates by the modification of the 2’,4’-position of the ribose with the inclusion of a bridge, efforts were focused on the inhibition of Taq DNA polymerase using quantitative real time PCR, and the results revealed the significant inhibitory effects of 2’,4’-bridged thymidine nucleoside on the polymerase. Study on the mode of inhibition revealed the competitive mechanism with which the 2’,4’-bridged thymidine operates. With a Ki value of 9.7 ± 1.1 μM, the 2’,4’-bridged thymidine proved to be a very promising inhibitor. Additionally, docking analysis showed that all the nucleosides including 2’,4’-bridged thymidine were able to dock in the active site, indicating that the substrate analogs reflect a structural complementarity to the enzyme active site. The analysis also provided evidence that Asp610 was a key binding site for 2’,4’-bridged thymidine. Molecular dynamics (MD) simulations were performed to further understand the conformational variations of the binding. The root-mean-square deviation (RMSD) values for the peptide backbone of the enzyme and the nitrogenous base of the inhibitor stabilized within 0.8 and 0.2 ns, respectively. Furthermore, the MD analysis indicates substantial conformational change in the ligand (inhibitor) as the nitrogenous base rotated anticlockwise with respect to the sugar moiety, complemented by the formation of several new hydrogen bonds where Arg587 served as a pivot axis for binding formation. In conclusion, the active site inhibition of Taq DNA polymerase by 2’,4’-bridged thymidine suggests the potential of bridged nucleosides as drug candidates.
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Affiliation(s)
- Sung-Kun Kim
- Northeastern State University, Department of Natural Sciences, Tahlequah, Oklahoma, United States of America
- * E-mail:
| | - Aaron Castro
- Bio-Synthesis Inc, Lewisville, Texas, United States of America
| | - Edward S. Kim
- Bio-Synthesis Inc, Lewisville, Texas, United States of America
| | - Austin P. Dinkel
- Northeastern State University, Department of Natural Sciences, Tahlequah, Oklahoma, United States of America
| | - Xiaoyun Liu
- Bio-Synthesis Inc, Lewisville, Texas, United States of America
| | - Miguel Castro
- Bio-Synthesis Inc, Lewisville, Texas, United States of America
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Abstract
Cell synchronization techniques have been used for the studies of mechanisms involved in cell cycle regulation. Synchronization involves the enrichment of subpopulations of cells in specific stages of the cell cycle. These subpopulations are then used to study regulatory mechanisms of the cell cycle such as DNA synthesis, gene expression, protein synthesis, protein phosphorylation, protein degradation, and development of new drugs (e.g., CDK inhibitors). Here, we describe several protocols for synchronization of cells from different phases of the cell cycle. We also describe protocols for determining cell viability and mitotic index and for validating the synchrony of the cells by flow cytometry.
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Affiliation(s)
- Beatriz Pérez-Benavente
- Oncogenic Signalling Laboratory, Centro de Investigación Príncipe Felipe de Valencia, Eduardo Primo Yúfera 3, 46012, Valencia, Spain
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Chandran J, Aravind UK, Aravindakumar CT. Sonochemical transformation of thymidine: A mass spectrometric study. Ultrason Sonochem 2015; 27:178-186. [PMID: 26186835 DOI: 10.1016/j.ultsonch.2015.05.016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Revised: 05/14/2015] [Accepted: 05/15/2015] [Indexed: 06/04/2023]
Abstract
Ultrasound is extensively used in medical field for a number of applications including targeted killing of cancer cells. DNA is one of the most susceptible entities in any kind of free radical induced reactions in living systems. In the present work, the transformation of thymidine (dT) induced by ultrasound (US) was investigated using high resolution mass spectrometry (LC-Q-ToF-MS). dT was subjected to sonolysis under four different frequencies (200, 350, 620 and 1000 kHz) and at three power densities (10.5, 24.5 and 42 W/mL) in aerated as well as argon saturated conditions. A total of twenty modified nucleosides including non-fully characterized dT dimeric compounds were detected by LC-Q-ToF-MS. Out of these products, seven were obtained only in the argon atmosphere and two only in the aerated conditions. Among the identified products, there were base modified products and sugar modified products. The products were formed by the reaction of hydroxyl radical and hydrogen atom. Under aerated conditions, the reactions proceed via the formation of hydroperoxides, while in argon atmosphere disproportionation and radical recombinations predominate. The study provides a complete picture of sonochemical transformation pathways of dT which has relevance in DNA damage under ultrasound exposure.
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Affiliation(s)
- Jisha Chandran
- Inter University Instrumentation Centre, Mahatma Gandhi University, Kottayam 686560, Kerala, India
| | - Usha K Aravind
- Advanced Centre of Environmental Science and Sustainable Development, Mahatma Gandhi University, Kottayam 686560, Kerala, India
| | - C T Aravindakumar
- Inter University Instrumentation Centre, Mahatma Gandhi University, Kottayam 686560, Kerala, India; School of Environmental Sciences, Mahatma Gandhi University, Kottayam 686560, Kerala, India.
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29
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Salpin JY, Scuderi D. Structure of protonated thymidine characterized by infrared multiple photon dissociation and quantum calculations. Rapid Commun Mass Spectrom 2015; 29:1898-1904. [PMID: 26411511 DOI: 10.1002/rcm.7296] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Revised: 07/23/2015] [Accepted: 07/29/2015] [Indexed: 06/05/2023]
Abstract
RATIONALE Many fundamental studies are motivated by the probable relationship between the presence of rare enol tautomers of nucleobases and point mutation developing during nucleic acid replication. The evaluation of the tautomeric behaviour of nucleobases is therefore of fundamental importance. This can be probed in the gas phase by combining action spectroscopy and mass spectrometry. METHODS Experimental Infrared Multiple Photon Dissociation spectra in the fingerprint region of electrospray-generated and subsequently selected ions were recorded at the CLIO free electron laser (FEL) facility, by coupling the FEL to a quadrupole ion trap, and compared to calculated harmonic vibrational infrared spectra of the different low-lying isomers computed at the B3LYP/6-31++G(d,p) level. Relative energies were refined using the extended basis set 6-311++G(3df,2p). RESULTS The Density Functional Theory (DFT) study shows that, as for protonated thymine, the global energy minimum of protonated thymidine corresponds to an enol tautomer, whose infrared absorption spectrum is found to be in very good agreement with the experimental IRMPD spectrum. A very weak IRMPD signal observed at ~1780 cm(-1) is very likely the signature of an oxo tautomer. Consequently, as for thymine, protonated thymidine generated by electrospray corresponds to a mixture of at least two tautomeric forms. CONCLUSIONS Tautomerization can be characterized by IRMPD spectroscopy. Interestingly, the dominant enolic tautomeric form(s) presently observed cannot be directly generated from the most stable neutral tautomer of the thymine residue.
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Affiliation(s)
- Jean-Yves Salpin
- Université d'Evry Val d'Essonne, Laboratoire Analyse et Modélisation pour la Biologie et l'Environnement, Boulevard François Mitterrand, 91025, Evry, France
- CNRS-UMR 8587
| | - Debora Scuderi
- Université Paris Sud Orsay, Laboratoire de Chimie Physique, Bâtiment 350, 91405, Orsay, France
- CNRS - UMR 8000
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Wang P, Amato NJ, Zhai Q, Wang Y. Cytotoxic and mutagenic properties of O4-alkylthymidine lesions in Escherichia coli cells. Nucleic Acids Res 2015; 43:10795-803. [PMID: 26400162 PMCID: PMC4678858 DOI: 10.1093/nar/gkv941] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2015] [Accepted: 09/08/2015] [Indexed: 11/18/2022] Open
Abstract
Due to the abundant presence of alkylating agents in living cells and the environment, DNA alkylation is generally unavoidable. Among the alkylated DNA lesions, O4-alkylthymidine (O4-alkyldT) are known to be highly mutagenic and persistent in mammalian tissues. Not much is known about how the structures of the alkyl group affect the repair and replicative bypass of the O4-alkyldT lesions, or how the latter process is modulated by translesion synthesis polymerases. Herein, we synthesized oligodeoxyribonucleotides harboring eight site-specifically inserted O4-alkyldT lesions and examined their impact on DNA replication in Escherichia coli cells. We showed that the replication past all the O4-alkyldT lesions except (S)- and (R)-sBudT was highly efficient, and these lesions directed very high frequencies of dGMP misincorporation in E. coli cells. While SOS-induced DNA polymerases play redundant roles in bypassing most of the O4-alkyldT lesions, the bypass of (S)- and (R)-sBudT necessitated Pol V. Moreover, Ada was not involved in the repair of any O4-alkyldT lesions, Ogt was able to repair O4-MedT and, to a lesser extent, O4-EtdT and O4-nPrdT, but not other O4-alkyldT lesions. Together, our study provided important new knowledge about the repair of the O4-alkyldT lesions and their recognition by the E. coli replication machinery.
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Affiliation(s)
- Pengcheng Wang
- Environmental Toxicology Graduate Program,University of California, Riverside, CA 92521-0403, USA
| | - Nicholas J Amato
- Department of Chemistry, University of California, Riverside, CA 92521-0403, USA
| | - Qianqian Zhai
- Department of Chemistry, University of California, Riverside, CA 92521-0403, USA
| | - Yinsheng Wang
- Environmental Toxicology Graduate Program,University of California, Riverside, CA 92521-0403, USA Department of Chemistry, University of California, Riverside, CA 92521-0403, USA
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Sledz W, Los E, Paczek A, Rischka J, Motyka A, Zoledowska S, Piosik J, Lojkowska E. Antibacterial activity of caffeine against plant pathogenic bacteria. Acta Biochim Pol 2015; 62:605-12. [PMID: 26307771 DOI: 10.18388/abp.2015_1092] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Revised: 08/07/2015] [Accepted: 08/10/2015] [Indexed: 11/10/2022]
Abstract
The objective of the present study was to evaluate the antibacterial properties of a plant secondary metabolite - caffeine. Caffeine is present in over 100 plant species. Antibacterial activity of caffeine was examined against the following plant-pathogenic bacteria: Ralstonia solanacearum (Rsol), Clavibacter michiganesis subsp. sepedonicus (Cms), Dickeya solani (Dsol), Pectobacterium atrosepticum (Pba), Pectobacterium carotovorum subsp. carotovorum (Pcc), Pseudomonas syringae pv. tomato (Pst), and Xanthomonas campestris subsp. campestris (Xcc). MIC and MBC values ranged from 5 to 20 mM and from 43 to 100 mM, respectively. Caffeine increased the bacterial generation time of all tested species and caused changes in cell morphology. The influence of caffeine on the synthesis of DNA, RNA and proteins was investigated in cultures of plant pathogenic bacteria with labelled precursors: [(3)H]thymidine, [(3)H]uridine or (14)C leucine, respectively. RNA biosynthesis was more affected than DNA or protein biosynthesis in bacterial cells treated with caffeine. Treatment of Pba with caffeine for 336 h did not induce resistance to this compound. Caffeine application reduced disease symptoms caused by Dsol on chicory leaves, potato slices, and whole potato tubers. The data presented indicate caffeine as a potential tool for the control of diseases caused by plant-pathogenic bacteria, especially under storage conditions.
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Affiliation(s)
- Wojciech Sledz
- Laboratory of Plant Protection and Biotechnology, Intercollegiate Faculty of Biotechnology, University of Gdansk and Medical University of Gdansk, Gdańsk, Poland
| | - Emilia Los
- Laboratory of Plant Protection and Biotechnology, Intercollegiate Faculty of Biotechnology, University of Gdansk and Medical University of Gdansk, Gdańsk, Poland
| | - Agnieszka Paczek
- Laboratory of Plant Protection and Biotechnology, Intercollegiate Faculty of Biotechnology, University of Gdansk and Medical University of Gdansk, Gdańsk, Poland
| | - Jacek Rischka
- Laboratory of Plant Protection and Biotechnology, Intercollegiate Faculty of Biotechnology, University of Gdansk and Medical University of Gdansk, Gdańsk, Poland
| | - Agata Motyka
- Laboratory of Plant Protection and Biotechnology, Intercollegiate Faculty of Biotechnology, University of Gdansk and Medical University of Gdansk, Gdańsk, Poland
| | - Sabina Zoledowska
- Laboratory of Plant Protection and Biotechnology, Intercollegiate Faculty of Biotechnology, University of Gdansk and Medical University of Gdansk, Gdańsk, Poland
| | - Jacek Piosik
- Laboratory of Plant Protection and Biotechnology, Intercollegiate Faculty of Biotechnology, University of Gdansk and Medical University of Gdansk, Gdańsk, Poland
| | - Ewa Lojkowska
- Laboratory of Plant Protection and Biotechnology, Intercollegiate Faculty of Biotechnology, University of Gdansk and Medical University of Gdansk, Gdańsk, Poland
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Chen SH, Wang YS, Chen YS, Tang X, Cao JX, Li MH, Wang XF, Zhu YF, Huang YQ. Dual-channel detection of metallothioneins and mercury based on a mercury-mediated aptamer beacon using thymidine-mercury-thymidine complex as a quencher. Spectrochim Acta A Mol Biomol Spectrosc 2015; 151:315-321. [PMID: 26143324 DOI: 10.1016/j.saa.2015.06.106] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2014] [Revised: 06/26/2015] [Accepted: 06/28/2015] [Indexed: 06/04/2023]
Abstract
A novel dual-channel strategy for the detection of metallothioneins (MTs) and Hg(2+) has been developed based on a mercury-mediated aptamer beacon (MAB) using thymidine-mercury-thymidine complex as a quencher for the first time. In the presence of Hg(2+), the T-rich oligonucleotide with a 6-carboxyfluorescein (TRO-FAM) can form an aptamer beacon via the formation of T-Hg(2+)-T base pairs, which results in a fluorescence quenching of the sensing system owing to the fluorescence resonance energy transfer (FRET) from the fluorophore of FAM to the terminated T-Hg(2+)-T base pair. The addition of MTs into this solution leads to the disruption of the T-Hg(2+)-T complex, resulting in an increase of the fluorescent signal of the system. In the optimizing condition, ΔF was directly proportional to the concentrations ranging from 5.63 nM to 0.275 μM for MTs, and 14.2 nM to 0.30 μM for Hg(2+) with the detection limits of 1.69 nM and 4.28 nM, respectively. The proposed dual-channel method avoids the label steps of a quencher in common molecular beacon strategies, without tedious procedure or the requirement of sophisticated equipment, and is rapid, inexpensive and sensitive.
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Affiliation(s)
- Si-Han Chen
- College of Public Health, University of South China, Hengyang 421001, PR China
| | - Yong-Sheng Wang
- College of Public Health, University of South China, Hengyang 421001, PR China.
| | - Yun-Sheng Chen
- College of Public Health, University of South China, Hengyang 421001, PR China
| | - Xian Tang
- College of Public Health, University of South China, Hengyang 421001, PR China
| | - Jin-Xiu Cao
- College of Public Health, University of South China, Hengyang 421001, PR China
| | - Ming-Hui Li
- College of Public Health, University of South China, Hengyang 421001, PR China
| | - Xiao-Feng Wang
- College of Public Health, University of South China, Hengyang 421001, PR China
| | - Yu-Feng Zhu
- College of Public Health, University of South China, Hengyang 421001, PR China
| | - Yan-Qin Huang
- College of Public Health, University of South China, Hengyang 421001, PR China
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Virgilio A, Petraccone L, Scuotto M, Vellecco V, Bucci M, Mayol L, Varra M, Esposito V, Galeone A. 5-Hydroxymethyl-2'-deoxyuridine residues in the thrombin binding aptamer: investigating anticoagulant activity by making a tiny chemical modification. Chembiochem 2014; 15:2427-34. [PMID: 25214456 DOI: 10.1002/cbic.201402355] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Indexed: 11/07/2022]
Abstract
We report an investigation into analogues of the thrombin binding aptamer (TBA). Individual thymidines were replaced by the unusual residue 5-hydroxymethyl-2'-deoxyuridine (hmU). This differs from the canonical thymidine by a hydroxyl group on the 5-methyl group. NMR and CD data clearly indicate that all TBA derivatives retain the ability to fold into the "chair-like" quadruplex structure. The presence of the hmU residue does not significantly affect the thermal stability of the modified aptamers compared to the parent, except for analogue H9, which showed a marked increase in melting temperature. Although all TBA analogues showed decreased affinities to thrombin, H3, H7, and H9 proved to have improved anticoagulant activities. Our data open up the possibility to enhance TBA biological properties, simply by introducing small chemical modifications.
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Affiliation(s)
- Antonella Virgilio
- Dipartimento di Farmacia, Università degli Studi di Napoli "Federico II", Via D. Montesano 49, 80131 Napoli (Italy)
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Perevozchikova SA, Trikin RM, Heinze RJ, Romanova EA, Oretskaya TS, Friedhoff P, Kubareva EA. Is thymidine glycol containing DNA a substrate of E. coli DNA mismatch repair system? PLoS One 2014; 9:e104963. [PMID: 25133614 PMCID: PMC4136841 DOI: 10.1371/journal.pone.0104963] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2014] [Accepted: 07/15/2014] [Indexed: 11/18/2022] Open
Abstract
The DNA mismatch repair (MMR) system plays a crucial role in the prevention of replication errors and in the correction of some oxidative damages of DNA bases. In the present work the most abundant oxidized pyrimidine lesion, 5,6-dihydro-5,6-dihydroxythymidine (thymidine glycol, Tg) was tested for being recognized and processed by the E. coli MMR system, namely complex of MutS, MutL and MutH proteins. In a partially reconstituted MMR system with MutS-MutL-MutH proteins, G/Tg and A/Tg containing plasmids failed to provoke the incision of DNA. Tg residue in the 30-mer DNA duplex destabilized double helix due to stacking disruption with neighboring bases. However, such local structural changes are not important for E. coli MMR system to recognize this lesion. A lack of repair of Tg containing DNA could be due to a failure of MutS (a first acting protein of MMR system) to interact with modified DNA in a proper way. It was shown that Tg in DNA does not affect on ATPase activity of MutS. On the other hand, MutS binding affinities to DNA containing Tg in G/Tg and A/Tg pairs are lower than to DNA with a G/T mismatch and similar to canonical DNA. Peculiarities of MutS interaction with DNA was monitored by Förster resonance energy transfer (FRET) and fluorescence anisotropy. Binding of MutS to Tg containing DNAs did not result in the formation of characteristic DNA kink. Nevertheless, MutS homodimer orientation on Tg-DNA is similar to that in the case of G/T-DNA. In contrast to G/T-DNA, neither G/Tg- nor A/Tg-DNA was able to stimulate ADP release from MutS better than canonical DNA. Thus, Tg residue in DNA is unlikely to be recognized or processed by the E. coli MMR system. Probably, the MutS transformation to active “sliding clamp” conformation on Tg-DNA is problematic.
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Affiliation(s)
- Svetlana A. Perevozchikova
- Department of Chemistry and Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Roman M. Trikin
- Institute of Cell Biology, University of Bern, Bern, Switzerland
| | - Roger J. Heinze
- Institute for Biochemistry, Justus Liebig University, Giessen, Germany
| | - Elena A. Romanova
- Department of Chemistry and Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Tatiana S. Oretskaya
- Department of Chemistry and Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Peter Friedhoff
- Institute for Biochemistry, Justus Liebig University, Giessen, Germany
| | - Elena A. Kubareva
- Department of Chemistry and Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
- * E-mail:
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35
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Wang P, Williams RT, Guerrero CR, Ji D, Wang Y. Fragmentation of electrospray-produced deprotonated ions of oligodeoxyribonucleotides containing an alkylated or oxidized thymidine. J Am Soc Mass Spectrom 2014; 25:1167-1176. [PMID: 24664806 PMCID: PMC4057974 DOI: 10.1007/s13361-014-0848-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2014] [Revised: 02/01/2014] [Accepted: 02/03/2014] [Indexed: 06/03/2023]
Abstract
Alkylation and oxidation constitute major routes of DNA damage induced by endogenous and exogenous genotoxic agents. Understanding the biological consequences of DNA lesions often necessitates the availability of oligodeoxyribonucleotide (ODN) substrates harboring these lesions, and sensitive and robust methods for validating the identities of these ODNs. Tandem mass spectrometry is well suited for meeting these latter analytical needs. In the present study, we evaluated how the incorporation of an ethyl group to different positions (i.e., O(2), N3, and O(4)) of thymine and the oxidation of its 5-methyl carbon impact collisionally activated dissociation (CAD) pathways of electrospray-produced deprotonated ions of ODNs harboring these thymine modifications. Unlike an unmodified thymine, which often manifests poor cleavage of the C3'-O3' bond, the incorporation of an alkyl group to the O(2) position and, to a much lesser extent, the O(4) position, but not the N3 position of thymine, led to facile cleavage of the C3'-O3' bond on the 3' side of the modified thymine. Similar efficient chain cleavage was observed when thymine was oxidized to 5-formyluracil or 5-carboxyluracil, but not 5-hydroxymethyluracil. Additionally, with the support of computational modeling, we revealed that proton affinity and acidity of the modified nucleobases govern the fragmentation of ODNs containing the alkylated and oxidized thymidine derivatives, respectively. These results provided important insights into the effects of thymine modifications on ODN fragmentation.
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Affiliation(s)
- Pengcheng Wang
- Environmental Toxicology Graduate Program, University of California, Riverside, California 92521-0403
| | - Renee T. Williams
- Department of Chemistry, University of California, Riverside, California 92521-0403
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, California 92093-0343
| | - Candace R. Guerrero
- Department of Chemistry, University of California, Riverside, California 92521-0403
| | - Debin Ji
- Department of Chemistry, University of California, Riverside, California 92521-0403
| | - Yinsheng Wang
- Environmental Toxicology Graduate Program, University of California, Riverside, California 92521-0403
- Department of Chemistry, University of California, Riverside, California 92521-0403
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Xing C, Yuan H, Xu S, An H, Niu R, Zhan Y. Nucleobase-functionalized conjugated polymer for detection of copper(II). ACS Appl Mater Interfaces 2014; 6:9601-9607. [PMID: 24893008 DOI: 10.1021/am502978w] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
In recent years, supramolecular organization of thiophene derivatives, oligo- and polythiophene, have been developed with various designs to achieve complex functions. Here, we describe the synthesis and characterization of a conjugated polymer with thymidine side chain bases and polythiophene backbones (PTT) instead of phosphate bonds in DNA, and the PTT exhibits exceptional fluorescence quenching efficiency upon binding of Cu(2+) ions in aqueous medium, which is suggested to be electron transfer from the π* orbit at the excited state of PTT to the 3d orbit of Cu(2+) ions and subsequent Cu(2+)-mediated interpolymer π-stacking aggregation. Furthermore, Cu(2+) ions can be selectively and easily monitored by the fluorescence quenching of PTT, which can be used for detection of Cu(2+) ions with good selectivity and high sensitivity in aqueous medium. Both experimental and theoretical methods have been devoted to demonstrate the strong affinity and steric interaction of PTT toward Cu(2+). These findings will illustrate new directions for the design of nucleobase-functionalized materials with transition metals responsive activity.
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Affiliation(s)
- Chengfen Xing
- Institute of Biophysics, Hebei University of Technology , Tianjin 300401, P. R. China
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Khalil A, Ishita K, Ali T, Tiwari R, Riachy R, Toppino A, Hasabelnaby S, Sayfullin N, Oliver AG, Gallucci J, Huang Z, Tjarks W. Iodine monochloride facilitated deglycosylation, anomerization, and isomerization of 3-substituted thymidine analogues. Nucleosides Nucleotides Nucleic Acids 2014; 33:786-99. [PMID: 25372994 PMCID: PMC4266569 DOI: 10.1080/15257770.2014.945648] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Accepted: 07/12/2014] [Indexed: 10/24/2022]
Abstract
The reaction of thymidine, 3-mono-, and 3,3',5'-trialkylsubstitued thymidine analogues with iodine monochloride (ICl) was investigated. Treatment with ICl resulted in rapid deglycosylation, anomerization, and isomerization of thymidine and 3-substituted thymidine analogues under various reaction conditions leading to the formation of the nucleobases as the major products accompanied by minor formation of α-furanosidic-, α-pyranosidic-, and β-pyranosidic nucleosides. On the other hand, 3,3',5'-trisubstitued thymidine analogues were only deglycosylated and anomerized. These results are similar to those observed for the acidic hydrolysis of the glycoside bond in nucleosides, but were presumably caused by the Lewis acid character of an iodine electrophile.
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Affiliation(s)
- Ahmed Khalil
- Division of Medicinal Chemistry & Pharmacognosy, College of Pharmacy, The Ohio State University, Columbus, Ohio
- Chemistry Department, Faculty of Science, Zagazig University, Zagazig, Egypt
| | - Keisuke Ishita
- Division of Medicinal Chemistry & Pharmacognosy, College of Pharmacy, The Ohio State University, Columbus, Ohio
| | - Tehane Ali
- Division of Medicinal Chemistry & Pharmacognosy, College of Pharmacy, The Ohio State University, Columbus, Ohio
| | - Rohit Tiwari
- Division of Medicinal Chemistry & Pharmacognosy, College of Pharmacy, The Ohio State University, Columbus, Ohio
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana
| | - Ramy Riachy
- Division of Medicinal Chemistry & Pharmacognosy, College of Pharmacy, The Ohio State University, Columbus, Ohio
| | - Antonio Toppino
- Division of Medicinal Chemistry & Pharmacognosy, College of Pharmacy, The Ohio State University, Columbus, Ohio
- Dipartimento di Chimica Generale e Chimica Organica, Università degli Studi di Torino, Torino, Italy
| | - Sherifa Hasabelnaby
- Division of Medicinal Chemistry & Pharmacognosy, College of Pharmacy, The Ohio State University, Columbus, Ohio
- Division of Pharmaceutical Organic Chemistry, College of Pharmacy, Helwan University, Ain Helwan, Cairo, Egypt
| | - Naum Sayfullin
- Division of Medicinal Chemistry & Pharmacognosy, College of Pharmacy, The Ohio State University, Columbus, Ohio
| | - Allen G. Oliver
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana
| | - Judith Gallucci
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio
| | - Zhenguo Huang
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio
| | - Werner Tjarks
- Division of Medicinal Chemistry & Pharmacognosy, College of Pharmacy, The Ohio State University, Columbus, Ohio
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Abstract
Photolysis of an aryl sulfide-containing 5,6-dihydropyrimidine (1) at 350 nm produces high yields of thymidine and products resulting from trapping of a 5,6-dihydrothymidin-5-yl radical by O₂ or thiols. Thymidine is believed to result from disproportionation of the radical pair originally generated from C--S bond homolysis of 1 on the microsecond timescale, which is significantly shorter than other photochemical transformations of modified nucleotides into their native forms. Duplex DNA containing 1 is destabilized, presumably due to disruption of π-stacking. Incorporation of 1 within the binding site of the restriction endonuclease EcoRV provides a photochemical switch for turning on the enzyme's activity. In contrast, 1 is a substrate for endonuclease VIII and serves as a photochemical off switch for this base excision repair enzyme. Modification 1 also modulates the activity of the 10-23 DNAzyme, despite its incorporation into a nonduplex region. Overall, dihydropyrimidine 1 shows promise as a tool to provide spatiotemporal control over DNA structure on the miscrosecond timescale.
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Mahesh Kumar J, Idris MM, Srinivas G, Vinay Kumar P, Meghah V, Kavitha M, Reddy CR, Mainkar PS, Pal B, Chandrasekar S, Nagesh N. Phenyl 1,2,3-triazole-thymidine ligands stabilize G-quadruplex DNA, inhibit DNA synthesis and potentially reduce tumor cell proliferation over 3'-azido deoxythymidine. PLoS One 2013; 8:e70798. [PMID: 23976957 PMCID: PMC3747139 DOI: 10.1371/journal.pone.0070798] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2013] [Accepted: 06/24/2013] [Indexed: 01/10/2023] Open
Abstract
Triazoles are known for their non-toxicity, higher stability and therapeutic activity. Few nucleoside (L1, L2 and L3) and non-nucleoside 1,2,3-triazoles (L4-L14) were synthesised using click chemistry and they were screened for tumor cell cytotoxicity and proliferation. Among these triazole ligands studied, nucleoside ligands exhibited higher potential than non-nucleoside ligands. The nucleoside triazole analogues, 3'-Phenyl-1,2,3- triazole-thymidine (L2) and 3'-4-Chlorophenyl-1,2,3-triazole-thymidine (L3), demonstrated higher cytotoxicity in tumor cells than in normal cells. The IC₅₀ value for L3 was lowest (50 µM) among the ligands studied. L3 terminated cell cycle at S, G2/M phases and enhanced sub-G1 populations, manifesting induction of apoptosis in tumor cells. Confocal studies indicated that nucleoside triazole ligands (L2/L3) cause higher DNA fragmentation than other ligands. Preclinical experiments with tumor-induced mice showed greater reduction in tumor size with L3. In vitro DNA synthesis reaction with L3 exhibited higher DNA synthesis inhibition with quadruplex forming DNA (QF DNA) than non quadruplex forming DNA (NQF DNA). T(m) of quadruplex DNA increased in the presence of L3, indicating its ability to enhance stability of quadruplex DNA at elevated temperature and the results indicate that it had higher affinity towards quadruplex DNA than the other forms of DNA (like dsDNA and ssDNA). From western blot experiment, it was noticed that telomerase expression levels in the tissues of tumor-induced mice were found to be reduced on L3 treatment. Microcalorimetry results emphasise that two nucleoside triazole ligands (L2/L3) interact with quadruplex DNA with significantly higher affinity (K(d)≈10⁻⁷ M). Interestingly the addition of an electronegative moiety to the phenyl group of L2 enhanced its anti-proliferative activity. Though IC₅₀ values are not significantly low with L3, the studies on series of synthetic 1,2,3-triazole ligands are useful for improving and building potential pro-apoptotic ligands.
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Affiliation(s)
| | | | - Gunda Srinivas
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad, India
| | | | | | - Mitta Kavitha
- CSIR-Indian Institute of Chemical Technology, Hyderabad, India
| | | | | | - Biswajit Pal
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad, India
| | | | - Narayana Nagesh
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad, India
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Shin MH, Park R, Nojima H, Kim HC, Kim YK, Chung JH. Atomic hydrogen surrounded by water molecules, H(H2O)m, modulates basal and UV-induced gene expressions in human skin in vivo. PLoS One 2013; 8:e61696. [PMID: 23637886 PMCID: PMC3634861 DOI: 10.1371/journal.pone.0061696] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2012] [Accepted: 03/12/2013] [Indexed: 01/16/2023] Open
Abstract
Recently, there has been much effort to find effective ingredients which can prevent or retard cutaneous skin aging after topical or systemic use. Here, we investigated the effects of the atomic hydrogen surrounded by water molecules, H(H2O)m, on acute UV-induced responses and as well as skin aging. Interestingly, we observed that H(H2O)m application to human skin prevented UV-induced erythema and DNA damage. And H(H2O)m significantly prevented UV-induced MMP-1, COX-2, IL-6 and IL-1β mRNA expressions in human skin in vivo. We found that H(H2O)m prevented UV-induced ROS generation and inhibited UV-induced MMP-1, COX-2 and IL-6 expressions, and UV-induced JNK and c-Jun phosphorylation in HaCaT cells. Next, we investigated the effects of H(H2O)m on intrinsically aged or photoaged skin of elderly subjects. In intrinsically aged skin, H(H2O)m application significantly reduced constitutive expressions of MMP-1, IL-6, and IL-1β mRNA. Additionally, H(H2O)m significantly increased procollagen mRNA and also decreased MMP-1 and IL-6 mRNA expressions in photoaged facial skin. These results demonstrated that local application of H(H2O)m may prevent UV-induced skin inflammation and can modulate intrinsic skin aging and photoaging processes. Therefore, we suggest that modifying the atmospheric gas environment within a room may be a new way to regulate skin functions or skin aging.
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Affiliation(s)
- Mi Hee Shin
- Department of Dermatology, Seoul National University College of Medicine, Seoul, Korea
- Laboratory of Cutaneous Aging Research, Biomedical Research Institute, Seoul National University Hospital, Seoul, Korea
- Institute of Human-Environment Interface Biology, Medical Research Center, Seoul National University, Seoul, Korea
| | - Raeeun Park
- R&D Team, Samsung Electronics CO., LTD, Suwon, Korea
| | - Hideo Nojima
- R&D Team, Samsung Electronics CO., LTD, Suwon, Korea
| | | | - Yeon Kyung Kim
- Department of Dermatology, Seoul National University College of Medicine, Seoul, Korea
- Laboratory of Cutaneous Aging Research, Biomedical Research Institute, Seoul National University Hospital, Seoul, Korea
- Institute of Human-Environment Interface Biology, Medical Research Center, Seoul National University, Seoul, Korea
| | - Jin Ho Chung
- Department of Dermatology, Seoul National University College of Medicine, Seoul, Korea
- Laboratory of Cutaneous Aging Research, Biomedical Research Institute, Seoul National University Hospital, Seoul, Korea
- Institute of Human-Environment Interface Biology, Medical Research Center, Seoul National University, Seoul, Korea
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Zhao Y, Liu G, Liu Y, Yuan L, Hawthorne D, Shen JX, Guha M, Aubry A. Improved ruggedness of an ion-pairing liquid chromatography/tandem mass spectrometry assay for the quantitative analysis of the triphosphate metabolite of a nucleoside reverse transcriptase inhibitor in peripheral blood mononuclear cells. Rapid Commun Mass Spectrom 2013; 27:481-488. [PMID: 23280981 DOI: 10.1002/rcm.6473] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2012] [Revised: 11/15/2012] [Accepted: 11/16/2012] [Indexed: 06/01/2023]
Abstract
RATIONALE Nucleotide analogs are highly polar and ionic, which impose great challenges on bioanalysis. Ion-pairing liquid chromatography/tandem mass spectrometry (LC/MS/MS) is the predominant reported approach for such compounds. Assay ruggedness of ion-pairing LC/MS/MS methods was often a challenge due to the potential contamination of the ion source of the mass spectrometer and LC column performance deterioration caused by ion-pairing reagents. METHODS An ion-pairing reagent was only added to the reconstitution solution to minimize its exposure to the MS ion source. To achieve optimum sensitivity, high pH mobile phases and negative ion ESI were needed for the LC/MS/MS method. However, high pH mobile phases led to the accumulation of ion-pairing reagent on the analytical column, which was washed off with an acidic solution to restore the column performance. In addition, isopropanol was used as a mobile phase modifier to improve peak shape and sensitivity. RESULTS The limit of detection was established at 1.0 ng/mL in the cell lysate. The calibration curve showed good linearity over the range of 1.0 to 100 ng/mL. The overall accuracy was no less than 87.7% based on four levels of quality control samples. Inter-run precision and intra-run precision across four analytical runs for low, geometric, medium and high QCs were less than 12.9. CONCLUSIONS By identifying and addressing the root cause of the assay ruggedness problem, we have developed a rugged ion-pairing LC/MS/MS method for a triphosphate (TP) metabolite of BMS-986001 in peripheral blood mononuclear cells. The new method overcame challenges such as a rapid deterioration of the peak shape, increased carryover and extremely poor column life. The peak shape was well maintained throughout multiple analytical runs. This method has been successfully applied to a toxicology study in cynomolgus monkey.
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Affiliation(s)
- Yue Zhao
- Bioanalytical Sciences Department, Research and Development, Bristol-Myers Squibb Co
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Agarwal HK, McElroy CA, Sjuvarsson E, Eriksson S, Darby MV, Tjarks W. Synthesis of N3-substituted carboranyl thymidine bioconjugates and their evaluation as substrates of recombinant human thymidine kinase 1. Eur J Med Chem 2012; 60:456-68. [PMID: 23318906 DOI: 10.1016/j.ejmech.2012.11.041] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2012] [Revised: 11/23/2012] [Accepted: 11/29/2012] [Indexed: 01/19/2023]
Abstract
Four different libraries of overall twenty three N3-substituted thymidine (dThd) analogues, including eleven 3-carboranyl thymidine analogues (3CTAs), were synthesized. The latter are potential agents for Boron Neutron Capture Therapy (BNCT) of cancer. Linker between the dThd scaffold and the m-carborane cluster at the N3-position of the 3CTAs contained amidinyl-(3e and 3f), guanidyl-(7e-7g), tetrazolylmethyl-(9b1/2-9d1/2), or tetrazolyl groups (11b1/2-11d1/2) to improve human thymidine kinase 1 (hTK1) substrate characteristics and water solubilities compared with 1st generation 3CTAs, such as N5 and N5-2OH. The amidinyl- and guanidyl-type N3-substitued dThd analogues (3a-3f and 7a-7g) had hTK1 phosphorylation rates of <30% relative to that of dThd, the endogenous hTK1 substrate, whereas the tetrazolyl-type N3-substitued dThd analogues (9a, 9b1/2-9d1/2 and 11a, 11b1/2-11d1/2) had relative phosphorylation rates (rPRs) of >40%. Compounds 9a, 9b1/2-9d1/2 and 11a, 11b1/2-11d1/2 were subjected to in-depth enzyme kinetics studies and the obtained rk(cat)/K(m) (k(cat)/K(m) relative to that of dThd) ranged from 2.5 to 26%. The tetrazolyl-type N3-substitued dThd analogues 9b1/2 and 11d1/2 were the best substrates of hTK1 with rPRs of 52.4% and 42.5% and rk(cat)/K(m) values of 14.9% and 19.7% respectively. In comparison, the rPR and rk(cat)/K(m) values of N5-2OH in this specific study were 41.5% and 10.8%, respectively. Compounds 3e and 3f were >1900 and >1500 times, respectively, better soluble in PBS (pH 7.4) than N5-2OH whereas solubilities for 9b1/2-9d1/2 and 11b1/2-11d1/2 were only 1.3-13 times better.
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Affiliation(s)
- Hitesh K Agarwal
- Division of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, The Ohio State University, Columbus, OH 43210, USA.
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Shilpa J, Roshni BT, Chinthu R, Paulose CS. Role of GABA and serotonin coupled chitosan nanoparticles in enhanced hepatocyte proliferation. J Mater Sci Mater Med 2012; 23:2913-2921. [PMID: 22960799 DOI: 10.1007/s10856-012-4754-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2012] [Accepted: 08/22/2012] [Indexed: 06/01/2023]
Abstract
The development of nanoparticles containing active molecules having improved stability, sustained release and maximum half life helps in cell proliferation result in enhanced tissue regeneration. Our study focuses on the use of Gamma amino butyric acid (GABA) and serotonin (5-HT) coupled chitosan nanoparticles for the active liver regeneration in male Wistar rats. The nanoparticles were prepared and the morphology was studied using SEM. The FT-IR spectra of the nanoparticles and the maximum encapsulation efficiency of GABA and 5-HT binding to chitosan nanoparticles were observed. The in vitro release studies provided the percentage release of GABA and 5-HT from the nanoparticles at different time intervals. The quantification of DNA and protein syntheses was done using [(3)H] thymidine and [(3)H] leucine uptake studies that determined the enhancement in hepatocyte proliferation. Our results project the role of GABA and 5-HT chitosan nanoparticles in the treatment of liver based diseases.
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Affiliation(s)
- J Shilpa
- Molecular Neurobiology and Cell Biology Unit, Centre for Neuroscience, Cochin University of Science and Technology, Cochin, 682 022, Kerala, India
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Abstract
O(2)- and O(4)-methylthymidine (O(2)-MdT and O(4)-MdT) can be induced in tissues of laboratory animals exposed with N-methyl-N-nitrosourea, a known carcinogen. These two O-methylated DNA adducts have been shown to be poorly repaired and may contribute to the mutations arising from exposure to DNA methylating agents. Here, in vitro replication studies with duplex DNA substrates containing site-specifically incorporated O(2)-MdT and O(4)-MdT showed that both lesions blocked DNA synthesis mediated by three different DNA polymerases, including the exonuclease-free Klenow fragment of Escherichia coli DNA polymerase I (Kf(-)), human DNA polymerase κ (pol κ), and Saccharomyces cerevisiae DNA polymerase η (pol η). Results from steady-state kinetic measurements and LC-MS/MS analysis of primer extension products revealed that Kf(-) and pol η preferentially incorporated the correct nucleotide (dAMP) opposite O(2)-MdT, while O(4)-MdT primarily directed dGMP misincorporation. While steady-state kinetic experiments showed that pol κ-mediated nucleotide insertion opposite O(2)-MdT and O(4)-MdT is highly promiscuous, LC-MS/MS analysis of primer extension products demonstrated that pol κ favorably incorporated the incorrect dGMP opposite both lesions. Our results underscored the limitation of the steady-state kinetic assay in determining how DNA lesions compromise DNA replication in vitro. In addition, the results from our study revealed that, if left unrepaired, O-methylated thymidine lesions may constitute important sources of nucleobase substitutions emanating from exposure to alkylating agents.
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Affiliation(s)
- Nisana Andersen
- Department of Chemistry, University of California, Riverside, California 92521-0403
| | - Jianshuang Wang
- Department of Chemistry, University of California, Riverside, California 92521-0403
| | - Pengcheng Wang
- Environmental Toxicology Graduate Program, University of California, Riverside, California 92521-0403
| | - Yong Jiang
- Environmental Toxicology Graduate Program, University of California, Riverside, California 92521-0403
| | - Yinsheng Wang
- Department of Chemistry, University of California, Riverside, California 92521-0403
- Environmental Toxicology Graduate Program, University of California, Riverside, California 92521-0403
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Lu C, Jiang Q, Tan C, Tang J, Zhang J. Preparation and preliminary biological evaluation of novel (99m)Tc-labelled thymidine analogs as tumor imaging agents. Molecules 2012; 17:8518-32. [PMID: 22801365 PMCID: PMC6269068 DOI: 10.3390/molecules17078518] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2012] [Revised: 06/27/2012] [Accepted: 07/05/2012] [Indexed: 11/16/2022] Open
Abstract
Two kinds of novel thymidine derivatives, N-thymidine-yl-N′-methyl-N′-{N′′-[2-sulfanyl-(ethylamino)acetyl]-2-aminoethylsulfanyl-1-hexanamide}-ethanediamine (TMHEA) and N-thymidine-yl-N′-methyl-N′-{N′′-[2-sulfanyl-(ethylamino)acetyl]-2-aminoethylsulfanyl-1-hexanamide}-hexanediamine (TMHHA) were prepared and successfully labeled with (99m)Tc in high labeling yields. The in vitro stability and in vivo biodistribution of (99m)Tc-TMHEA and (99m)Tc-TMHHA were investigated and compared. The biodistribution studies indicate that the radiotracer (99m)Tc-TMHEA displays selective tumor uptake, suggesting it is a potential tumor imaging agent.
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Affiliation(s)
- Chunxiong Lu
- Key Laboratory of Nuclear Medicine, Ministry of Health-Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi 214063, China.
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Aviñó A, Mazzini S, Ferreira R, Gargallo R, Marquez VE, Eritja R. The effect on quadruplex stability of North-nucleoside derivatives in the loops of the thrombin-binding aptamer. Bioorg Med Chem 2012; 20:4186-93. [PMID: 22727781 PMCID: PMC3534854 DOI: 10.1016/j.bmc.2012.06.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2012] [Revised: 05/31/2012] [Accepted: 06/02/2012] [Indexed: 11/29/2022]
Abstract
Modified thrombin-binding aptamers (TBAs) carrying uridine (U), 2'-deoxy-2'-fluorouridine (FU) and North-methanocarbathymidine (NT) residues in the loop regions were synthesized and analyzed by UV thermal denaturation experiments and CD spectroscopy. The replacement of thymidines in the TGT loop by U and FU results in an increased stability of the antiparallel quadruplex structure described for the TBA while the presence of NT residues in the same positions destabilizes the antiparallel structure. The substitution of the thymidines in the TT loops for U, FU and NT induce a destabilization of the antiparallel quadruplex, indicating the crucial role of these positions. NMR studies on TBAs modified with uridines at the TGT loop also confirm the presence of the antiparallel quadruplex structure. Nevertheless, replacement of two Ts in the TT loops by uridine gives a more complex scenario in which the antiparallel quadruplex structure is present along with other partially unfolded species or aggregates.
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Affiliation(s)
- Anna Aviñó
- Institute for Research in Biomedicine (IRB Barcelona), Networking Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN) and Institute for Advanced Chemistry of Catalonia (IQAC), CSIC, Baldiri Reixac 10, E-08028 Barcelona. Spain
| | - Stefania Mazzini
- Dipartimento di Scienze Molecolari Agroalimentari, Università degli Studi di Milano, via Celoria 2, 20133 Milano, Italy
| | - Ruben Ferreira
- Institute for Research in Biomedicine (IRB Barcelona), Networking Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN) and Institute for Advanced Chemistry of Catalonia (IQAC), CSIC, Baldiri Reixac 10, E-08028 Barcelona. Spain
| | - Raimundo Gargallo
- Department of Analytical Chemistry, University of Barcelona, Diagonal 647, E-08028 Barcelona, Spain
| | - Victor E. Marquez
- Chemical Biology Laboratory, Center for Cancer Research, National Cancer Institute at Frederick, Frederick, Maryland 21702. USA
| | - Ramon Eritja
- Institute for Research in Biomedicine (IRB Barcelona), Networking Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN) and Institute for Advanced Chemistry of Catalonia (IQAC), CSIC, Baldiri Reixac 10, E-08028 Barcelona. Spain
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Gillan DC, Pede A, Sabbe K, Gao Y, Leermakers M, Baeyens W, Louriño Cabana B, Billon G. Effect of bacterial mineralization of phytoplankton-derived phytodetritus on the release of arsenic, cobalt and manganese from muddy sediments in the Southern North Sea. A microcosm study. Sci Total Environ 2012; 419:98-108. [PMID: 22281039 DOI: 10.1016/j.scitotenv.2011.12.034] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2011] [Revised: 11/22/2011] [Accepted: 12/13/2011] [Indexed: 05/31/2023]
Abstract
Muddy sediments of the Belgian Continental Zone (BCZ) are contaminated by metals such as Co, As, Cd, Pb, and Ni. Previous studies have suggested that mineralization of phytodetritus accumulating each year on sediments might cause secondary contaminations of the overlying seawater (metal effluxes). The aim of the present research was to investigate these effluxes using a microcosm approach. Muddy sediments were placed in microcosms (diameter: 15 cm) and overlaid by phytodetritus (a mix of Phaeocystis globosa with the diatom Skeletonema costatum). The final suspension was 130.6 mg L(-1) (dw) and the final chlorophyll a content was 750 ± 35 μg L(-1) (mean ± SD). Natural seawater was used for controls. Microcosms were then incubated in the dark at 15°C during 7 days. Metals were monitored in overlying waters and microbial communities were followed using bacterial and nanoflagellate DAPI counts, thymidine incorporation, community level physiological profiling (CLPP) and fluorescein diacetate analysis (FDA). Benthic effluxes observed in sediments exposed to phytodetritus were always more elevated than those observed in controls. Large effluxes were observed for Mn, Co and As, reaching 1084 nmol m(-2)day(-1) (As), 512 nmol m(-2)day(-1) (Co), and 755 μmol m(-2)day(-1) (Mn). A clear link was established between heterotrophic microbial activity and metal effluxes. The onset of mineralization was very fast and started within 2h of deposition as revealed by CLPP. An increased bacterial production was observed after two days (8.7 mg Cm(-2)day(-2)) and the bacterial biomass appeared controlled by heterotrophic nanoflagellates. Calculations suggest that during phytoplankton blooms the microbial activity alone may release substantial amounts of dissolved arsenic in areas of the BCZ covered by muddy sediments.
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Abstract
Diastereomeric 8,5'-cyclopurine 2'-deoxynucleosides, containing a covalent bond between the deoxyribose and the purine base, are induced in DNA by ionizing radiation. They are suspected to play a role in the etiology of neurodegeneration in xeroderma pigmentosum patients. If not repaired, the S-8,5'-cyclo-2'-deoxyguanosine lesion (S-cdG) induces Pol V-dependent mutations at a frequency of 34% in Escherichia coli. Most are S-cdG → A transitions, suggesting mis-incorporation of dTTP opposite the lesion during replication bypass, although low levels of S-cdG → T transversions, arising from mis-incorporation of dATP, are also observed. We report the structures of 5'-d(GTGCXTGTTTGT)-3'·5'-d(ACAAACAYGCAC)-3', where X denotes S-cdG and Y denotes either dA or dT, corresponding to the situation following mis-insertion of either dTTP or dATP opposite the S-cdG lesion. The S-cdG·dT mismatch pair adopts a wobble base pairing. This provides a plausible rationale for the S-cdG → A transitions. The S-cdG·dA mismatch pair differs in conformation from the dG·dA mismatch pair. For the S-cdG·dA mismatch pair, both S-cdG and dA intercalate, but no hydrogen bonding is observed between S-cdG and dA. This is consistent with the lower levels of S-cdG → T transitions in E. coli.
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Affiliation(s)
- Hai Huang
- Department of Chemistry, Center in
Molecular Toxicology, and Center for Structural Biology, Vanderbilt-Ingram Cancer Center, Vanderbilt University, Nashville, Tennessee 37235,
United States
| | - Rajat
S. Das
- Department
of Chemistry, University of Connecticut, Storrs, Connecticut 06269, United States
| | - Ashis K. Basu
- Department
of Chemistry, University of Connecticut, Storrs, Connecticut 06269, United States
| | - Michael P. Stone
- Department of Chemistry, Center in
Molecular Toxicology, and Center for Structural Biology, Vanderbilt-Ingram Cancer Center, Vanderbilt University, Nashville, Tennessee 37235,
United States
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Adrjanowicz K, Wojnarowska Z, Grzybowska K, Hawelek L, Kaminski K, Paluch M, Kasprzycka A, Walczak K. Molecular dynamics and crystallization phenomenon of supercooled and glassy DNA and RNA nucleosides: β-adenosine, β-thymidine, and β-uridine. Phys Rev E Stat Nonlin Soft Matter Phys 2011; 84:051507. [PMID: 22181422 DOI: 10.1103/physreve.84.051507] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2011] [Revised: 10/26/2011] [Indexed: 05/31/2023]
Abstract
Nucleosides are chemical compounds that have an extremely important biological role; they can be found in all types of living organisms. They are crucial components from which DNA and RNA acids are built. In addition, nucleosides are key regulators of many physiological processes. In this paper, the molecular dynamics in the liquid and glassy state of three selected nucleosides, β-adenosine, β-thymidine, and β-uridine, was investigated by means of dielectric spectroscopy. Our results revealed multiple relaxation processes associated with different types of molecular motions. Besides the primary α relaxation, two secondary modes in the glassy states of examined compounds were identified. Crystallization progress monitored by dielectric spectroscopy and x-ray diffraction technique at isostructural relaxation conditions revealed that the examined nucleosides possess completely different tendencies to recrystallize from the liquid as well as the glassy state. We have also made an attempt to predict the time scale of molecular motion below the glass transition temperatures of the respective nucleosides to discuss their potential stability at room temperature over prolonged storage time. Finally, combination of molecular mobility studies with evaluation of thermodynamic parameters from calorimetric measurements allowed us to discuss the fundamental roles of both kinetic and thermodynamic factors in governing the physical stability of the glassy state.
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Affiliation(s)
- K Adrjanowicz
- Institute of Physics, University of Silesia, Katowice, Poland.
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