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Dang A, Nguyen HTH, Ruiz H, Piacentino E, Ryzhov V, Tureček F. Experimental Evidence for Noncanonical Thymine Cation Radicals in the Gas Phase. J Phys Chem B 2017; 122:86-97. [DOI: 10.1021/acs.jpcb.7b09872] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Andy Dang
- Department
of Chemistry, University of Washington, Bagley Hall, Box 351700, Seattle, Washington 98195-1700, United States
| | - Huong T. H. Nguyen
- Department
of Chemistry, University of Washington, Bagley Hall, Box 351700, Seattle, Washington 98195-1700, United States
| | - Heather Ruiz
- Department
of Chemistry and Biochemistry, Northern Illinois University, DeKalb, Illinois 60115, United States
| | - Elettra Piacentino
- Department
of Chemistry and Biochemistry, Northern Illinois University, DeKalb, Illinois 60115, United States
| | - Victor Ryzhov
- Department
of Chemistry and Biochemistry, Northern Illinois University, DeKalb, Illinois 60115, United States
| | - František Tureček
- Department
of Chemistry, University of Washington, Bagley Hall, Box 351700, Seattle, Washington 98195-1700, United States
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Sosnowska M, Makurat S, Zdrowowicz M, Rak J. 5-Selenocyanatouracil: A Potential Hypoxic Radiosensitizer. Electron Attachment Induced Formation of Selenium Centered Radical. J Phys Chem B 2017; 121:6139-6147. [PMID: 28574710 DOI: 10.1021/acs.jpcb.7b03633] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The propensity of 5-selenocyanatouracil (SeCNU) to decomposition induced by attachment of electron was scrutinized with the G3B3 composite quantum-chemical method and radiolytic studies. Favorable thermodynamic (Gibbs free reaction energy of -13.65 kcal/mol) and kinetic (Gibbs free activation energy of 1.22 kcal/mol) characteristics revealed by the G3B3 free energy profile suggest SeCNU to be sensitive to electron attachment. The title compound was synthesized in the reaction between uracil and selenocyanogen chloride in acetic acid. Then, an aqueous and deoxygenated solution of the HPLC purified compound containing tert-butanol as a hydroxyl radical scavenger was irradiated with X-rays. SeCNU radio-degradation results in two major products: the U-Se-Se-U dimer and the adduct of the ●OtBu radical to the U-Se● radical, U-Se-OtBu. The effects of radiolysis as well as the results of G3B3 calculations point to U-Se● as the primary product of dissociative electron attachment to SeCNU. The MTT test shows that SeCNU is nontoxic in vitro in concentrations equal to or lower than 10-6 M. Ionizing radiation will probably induce cytotoxic intra- and interstrand DNA cross-links as well as protein-DNA cross-links in the genomic DNA labeled with SeCNU.
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Affiliation(s)
- Marta Sosnowska
- Department of Chemistry, University of Gdańsk , Wita Stwosza 63, 80-308 Gdańsk, Poland
| | - Samanta Makurat
- Department of Chemistry, University of Gdańsk , Wita Stwosza 63, 80-308 Gdańsk, Poland
| | - Magdalena Zdrowowicz
- Department of Chemistry, University of Gdańsk , Wita Stwosza 63, 80-308 Gdańsk, Poland
| | - Janusz Rak
- Department of Chemistry, University of Gdańsk , Wita Stwosza 63, 80-308 Gdańsk, Poland
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Knorre DG, Fedorova OS, Frolova EI. Oxidative degradation of nucleic acids. RUSSIAN CHEMICAL REVIEWS 2007. [DOI: 10.1070/rc1993v062n01abeh000006] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Buchko GW, Weinfeld M. DNA-targeted 2-nitroimidazoles: studies of the influence of the phenanthridine-linked nitroimidazoles, 2-NLP-3 and 2-NLP-4, on DNA damage induced by ionizing radiation. Radiat Res 2002; 158:302-10. [PMID: 12175307 DOI: 10.1667/0033-7587(2002)158[0302:dtnsot]2.0.co;2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The nitroimidazole-linked phenanthridines 2-NLP-3 (5-[3-(2-nitro-1-imidazoyl)-propyl]-phenanthridinium bromide) and 2-NLP-4 (5-[3-(2-nitro-1-imidazoyl)-butyl]-phenanthridinium bromide) are composed of the radiosensitizer, 2-nitroimidazole, attached to the DNA intercalator phenanthridine by a 3- and 4-carbon linker, respectively. Previous in vitro assays showed both compounds to be 10-100 times more efficient as hypoxic cell radiosensitizers (based on external drug concentrations) than the untargeted 2-nitroimidazole radiosensitizer, misonidazole (Cowan et al., Radiat. Res. 127, 81-89, 1991). Here we have used a (32)P postlabeling assay and 5'-end-labeled oligonucleotide assay to compare the radiation-induced DNA damage generated in the presence of 2-NLP-3, 2-NLP-4, phenanthridine and misonidazole. After irradiation of the DNA under anoxic conditions, we observed a significantly greater level of 3'-phosphoglycolate DNA damage in the presence of 2-NLP-3 or 2-NLP-4 compared to irradiation of the DNA in the presence of misonidazole. This may account at least in part for the greater cellular radiosensitization shown by the nitroimidazole-linked phenanthridines over misonidazole. Of the two nitroimidazole-linked phenanthridines, the better in vitro radiosensitizer, 2-NLP-4, generated more 3'-phosphoglycolate in DNA than did 2-NLP-3. At all concentrations, phenanthridine had little effect on the levels of DNA damage, suggesting that the enhanced radiosensitization displayed by 2-NLP-3 and 2-NLP-4 is due to the localization of the 2-nitroimidazole to the DNA by the phenanthridine substituent and not to radiosensitization by the phenanthridine moiety itself.
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Affiliation(s)
- Garry W Buchko
- Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington 99352, USA
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Shibamoto Y, Zhou L, Hatta H, Mori M, Nishimoto S. A novel class of antitumor prodrug, 1-(2'-oxopropyl)-5-fluorouracil (OFU001), that releases 5-fluorouracil upon hypoxic irradiation. Jpn J Cancer Res 2000; 91:433-8. [PMID: 10804292 PMCID: PMC5926472 DOI: 10.1111/j.1349-7006.2000.tb00963.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
We have been developing prodrugs of anticancer agents such as 5-fluorouracil (5-FU) that are activated by irradiation under hypoxic conditions via one-electron reduction. Among them, OFU001 [1-(2'-oxopropyl)-5-fluorouracil] is a prototype radiation-activated prodrug. In this study, we investigated the radiation chemical reactivity and the biological effects of OFU001. This prodrug is presumed to release 5-FU through incorporation of hydrated electrons into the antibonding sigma * orbital of the C(1')-N(1) bond. Hydrated electrons are active species derived from radiolysis of water, but are readily deactivated by O(2) into superoxide anion radicals (O(2).(-)) under conditions of aerobic irradiation. Therefore, 5-FU release occurs highly specifically upon irradiation under hypoxic conditions. OFU001 dissolved in phosphate buffer released 5-FU with a G-value (mol number of molecules that are decomposed or produced by 1 J of absorbed radiation energy) of 1.9 x 10(-7) mol / J following hypoxic irradiation, while the G-value for 5-FU release was 1.0 x 10(-8) mol/J following aerobic irradiation. However, the G-values for decomposition of OFU001 were almost the same, i.e., 3.4 x 10(-7) mol/J following hypoxic irradiation and 2. 5 x 10(-7) mol / J following aerobic irradiation. When hypoxically irradiated (7.5 - 30 Gy) OFU001 was added to murine SCCVII cells for 1 - 24 h, a significant cell-killing effect was observed. The degree of this cytotoxicity was consistent with that of authentic 5-FU at the corresponding concentrations. On the other hand, cytotoxicity was minimal when the cells were treated with aerobically irradiated or unirradiated OFU001. This compound had no radiosensitizing effect against SCCVII cells under either aerobic or hypoxic conditions when the drug was removed immediately after irradiation. Since hypoxia is generally most marked in tumors and irradiation is applied at the tumor site, this concept of prodrug design appears to be potentially useful for selective tumor treatment with minimal adverse effects of anticancer agents.
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Affiliation(s)
- Y Shibamoto
- Department of Oncology, Institute for Frontier Medical Sciences, Kyoto University, Kyoto 606-8507, Japan.
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Morimoto S, Hatta H, Fujita S, Matsuyama T, Ueno T, Nishimoto S. Hydroxyl radical-induced cross-linking of thymine and lysine: identification of the primary structure and mechanism. Bioorg Med Chem Lett 1998; 8:865-70. [PMID: 9871556 DOI: 10.1016/s0960-894x(98)00124-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Hydroxyl radical-induced formation of a cross-link of thymine (Thy) and lysine (Lys) in the gamma-radiolysis of N2O-saturated aqueous solution was studied. A Thy-Lys cross-link (I) of the formal structure that OH radical and 4-carbon-centered Lys radical added respectively to C(5) and C(6) positions of Thy was isolated by a preparative HPLC and identified by a FAB-HRMS. The primary cross-link I was dehydrated by treatment with HCl at 120 degrees C to yield the secondary structure (II) possessing a C(5)-C(6) double bond in the Thy moiety: the latter structure II was reported previously (Dizdaroglu, M.; Gajewski, E. Cancer Res. 1989, 49, 3463-3467). A pulse radiolysis study with a redox titration method indicated that 4-carbon centered Lys radical intermediate was of neutral redox reactivity in contrast to reducing reactivity of 5-hydroxy-5,6-dihydrothymin-6-yl radical intermediate. The cross-link I could be formed by a conventional radical recombination mechanism, but not by an ionic recombination mechanism involving a redox reaction between the radical intermediates.
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Affiliation(s)
- S Morimoto
- Department of Energy and Hydrocarbon Chemistry, Graduate School of Engineering, Kyoto University, Japan
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Pulse radiolytic investigations on the reaction of the 6-yl radicals of uracils with Cu(II)-amino acid complexes. Radiat Phys Chem Oxf Engl 1993 1996. [DOI: 10.1016/0969-806x(96)00015-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Kagiya T, Nishimoto S, Shibamoto Y, Wang J, Zhou L, He YL, Sasai K, Takahashi M, Abe M. Importance of tumor affinity of nitroazoles in hypoxic radiosensitization. Int J Radiat Oncol Biol Phys 1989; 16:1033-7. [PMID: 2703382 DOI: 10.1016/0360-3016(89)90910-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
In vitro and in vivo sensitizing activities of a variety of nitroazole derivatives including misonidazole (MISO), SR-2508, and RSU-1069 were correlated by the aid of pharmacokinetic measurements of the drug uptake in animal solid tumors. The sensitizer enhancement ratio in vivo (SERvivo) on solid tumors increased linearly with the square root of administrated dose (Ds). The specific activity (A) in vivo of nitroazoles was evaluated from the square-root empirical relationship, SERvivo = 1.00 + A D1/2S. The intratumor concentration of nitroazoles at a given time t after administration was in proportion to the DS, in which the proportional constant was defined as the tumor-affinity factor FT,t. The absolute molar activity alpha M defined by A(M/FT,t)1/2, where M is the molecular weight of nitroazoles, showed a linear relationship with the SER in vitro (SERvitro) at 1 mM of sensitizers. The sensitizer dose required to achieve an SERvivo of 1.5 (DS,1.5) decreased and thus the overall sensitizing efficiency on animal solid tumors increased as the FT,t became greater.
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Affiliation(s)
- T Kagiya
- Department of Hydrocarbon Chemistry, Faculty of Engineering, Kyoto University, Japan
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Wardman P. The competition between oxidants and reductants in modifying radiation damage to DNA. FREE RADICAL RESEARCH COMMUNICATIONS 1989; 6:145-7. [PMID: 2744592 DOI: 10.3109/10715768909073454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- P Wardman
- Gray Laboratory of the Cancer Research Campaign, Mount Vernon Hospital, Northwood, Middx., England
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Kagiya VT, Nishimoto S. A physicochemical aspect of radioprotection and sensitized cancer radiotherapy. FREE RADICAL RESEARCH COMMUNICATIONS 1989; 6:191-4. [PMID: 2744601 DOI: 10.3109/10715768909073468] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- V T Kagiya
- Department of Hydrocarbon Chemistry, Faculty of Engineering, Kyoto University, Japan
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Roles of oxygen and oxygen substitutes in DNA sugar damage by antitumor antibiotics. BASIC LIFE SCIENCES 1988; 49:745-57. [PMID: 2977947 DOI: 10.1007/978-1-4684-5568-7_119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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Chin DH, Kappen LS, Goldberg IH. 3'-Formyl phosphate-ended DNA: high-energy intermediate in antibiotic-induced DNA sugar damage. Proc Natl Acad Sci U S A 1987; 84:7070-4. [PMID: 2959956 PMCID: PMC299231 DOI: 10.1073/pnas.84.20.7070] [Citation(s) in RCA: 32] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Under anaerobic conditions where the nitroaromatic radiation-sensitizer misonidazole substitutes for dioxygen, DNA strand breakage (gaps with phosphate residues at each end) by the nonprotein chromophore of the antitumor antibiotic neocarzinostatin (NCS-Chrom) is associated with the generation of a reactive form of formate from the C-5' of deoxyribose of thymidylate residues. Such lesions account for a minority (10-15%) of the strand breakage found in the aerobic reaction without misonidazole. Amino-containing nucleophiles such as tris(hydroxymethyl)aminomethane (Tris) and hydroxylamine act as acceptors for the activated formate. The amount of [3H]formyl hydroxamate produced from DNA labeled with [5'-3H]thymidine is comparable to the spontaneously released thymine. During the course of the reaction, misonidazole undergoes a DNA-dependent reduction and subsequent conjugation with glutathione used to activate NCS-Chrom. From these and earlier results, we propose a possible mechanism in which the carbon-centered radical formed at C-5' by hydrogen atom abstraction by thiol-activated NCS-Chrom reacts anaerobically with misonidazole to form a nitroxyl-radical-adduct intermediate, which fragments to produce an oxy radical at C-5'. beta-Fragmentation results in cleavage between C-5' and C-4' with the generation of 3'-formyl phosphate-ended DNA, a high-energy form of formate, which spontaneously hydrolyzes, releasing formate and creating a 3'-phosphate end, or transfers the formyl moiety to available nucleophiles. A similar mechanism, involving dioxygen addition, is probably responsible for the 10-15% DNA gap formation in the aerobic reaction.
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Affiliation(s)
- D H Chin
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115
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