1
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Anaya-Gonzalez C, Soldevila S, Garcia-Lainez G, Bosca F, Andreu I. Chemical tuning for potential antitumor fluoroquinolones. Free Radic Biol Med 2019; 141:150-158. [PMID: 31195085 DOI: 10.1016/j.freeradbiomed.2019.06.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Revised: 06/05/2019] [Accepted: 06/07/2019] [Indexed: 12/12/2022]
Abstract
Phototoxic effects of 6,8 dihalogenated quinolones confers to this type of molecules a potential property as photochemotherapeutic agents. Two photodehalogenation processes seem to be involved in the remarkable photoinduced cellular damage. In this context, a new 6,8 dihalogenated quinolone 1 (1-methyl-6,8-difluoro-4-oxo-7-aminodimethyl-1,4-dihydroquinoline-3-carboxylic acid) was synthetized looking for improving the phototoxic properties of fluoroquinolones (FQ) and to determine the role of the photodegradation pathways in the FQ phototoxicity. With this purpose, fluorescence emissions, laser flash photolysis experiments and photodegradation studies were performed with compound 1 using 1-ethyl-6,8-difluoro-4-oxo-7-aminodimethyl-1,4-dihidroquinoline-3-carboxylic acid (2) and lomefloxacin (LFX) as reference compounds. The shortening of alkyl chain of the N(1) of the quinolone ring revealed a lifetime increase of the reactive aryl cation generated from photolysis of the three FQ and a significant reduction of the FQ photodegradation quantum yield. The fact that these differences were smaller when the same study was done using a hydrogen donor solvent (ethanol-aqueous buffer, 50/50 v/v) evidenced the highest ability of the reactive intermediate arising from 1 to produce intermolecular alkylations. These results were correlated with in vitro 3T3 NRU phototoxicity test. Thus, when Photo-Irritation-Factor (PIF) was determined for 1, 2 and LFX using cytotoxicity profiles of BALB/c 3T3 fibroblasts treated with each compound in the presence and absence of UVA light, a PIF more higher than 30 was obtained for 1 while the values for 2 and LFX were only higher than 8 and 10, respectively. Thereby, the present study illustrates an approach to modulate the photosensitizing properties of FQ with the purpose to improve the chemotherapeutic properties of antitumor quinolones. Moreover, the results obtained in this study also evidence that the key pathway responsible for the phototoxic properties associated with dihalogenated quinolones is the aryl cation generation.
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Affiliation(s)
- Cristina Anaya-Gonzalez
- Instituto Mixto de Tecnología Química. Consejo Superior de Investigaciones Científicas/Universidad Politécnica de Valencia (CSIC/UPV) Avd. Los Naranjos s/n, 46022, Valencia, Spain
| | - Sonia Soldevila
- Instituto Mixto de Tecnología Química. Consejo Superior de Investigaciones Científicas/Universidad Politécnica de Valencia (CSIC/UPV) Avd. Los Naranjos s/n, 46022, Valencia, Spain
| | - Guillermo Garcia-Lainez
- Instituto de Investigación Sanitaria (IIS) La Fe, Hospital Universitari i Politècnic La Fe, Avenida de Fernando Abril Martorell 106, 46026, Valencia, Spain
| | - Francisco Bosca
- Instituto Mixto de Tecnología Química. Consejo Superior de Investigaciones Científicas/Universidad Politécnica de Valencia (CSIC/UPV) Avd. Los Naranjos s/n, 46022, Valencia, Spain.
| | - Inmaculada Andreu
- Instituto de Investigación Sanitaria (IIS) La Fe, Hospital Universitari i Politècnic La Fe, Avenida de Fernando Abril Martorell 106, 46026, Valencia, Spain; Unidad Mixta de Investigación UPV-Instituto de Investigación Sanitaria (IIS) La Fe, Hospital Universitari i Politècnic La Fe, Avenida de Fernando Abril Martorell 106, 46026, Valencia, Spain
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2
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Luo T, Chen J, Li X, Zhang S, Yao H, Peijnenburg WJGM. Effects of lomefloxacin on survival, growth and reproduction of Daphnia magna under simulated sunlight radiation. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2018; 166:63-70. [PMID: 30248562 DOI: 10.1016/j.ecoenv.2018.09.067] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Revised: 09/11/2018] [Accepted: 09/15/2018] [Indexed: 06/08/2023]
Abstract
Lomefloxacin, an antibacterial agent with known photo-induced toxicity in clinical studies, is frequently detected in aquatic environments. Investigating the photo-induced toxicity of lomefloxacin in aquatic organisms is therefore of importance for assessing its ecological risks. In this study, the effects of lomefloxacin on survival, growth and reproduction of Daphnia magna under simulated sunlight radiation (SSR) were investigated, and the mechanism of action was revealed. Results indicated that SSR containing UV radiation increased the acute toxicity of lomefloxacin to Daphnia magna relative to white fluorescent light irradiation. Under SSR, 100 μM lomefloxacin significantly enhanced reactive oxygen species (ROS) generation and lipid peroxidation, and decreased activities of superoxide dismutase and catalase. The biochemical observations and apparent effects on the organism indicate that oxidative stress plays a central role in the acute photo-induced toxicity. Chronic toxicity results showed that SSR significantly affected growth and reproduction of Daphnia magna, whereas lomefloxacin reduced the damage of UV radiation in SSR through light shielding. This study provides insight into the mechanism of photo-induced toxicity and can support the risk assessment of chemicals in the aquatic environment by including the impacts of sunlight irradiation on toxicity.
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Affiliation(s)
- Tianlie Luo
- Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Jingwen Chen
- Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China.
| | - Xuehua Li
- Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Shuying Zhang
- Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Hongye Yao
- Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Willie J G M Peijnenburg
- Institute of Environmental Sciences, Leiden University, 2300 RA Leiden, the Netherlands; National Institute of Public Health and the Environment, Center for the Safety of Substances and Products, 3720 BA Bilthoven, the Netherlands
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3
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Jantová S, Mrvová N, Hudec R, Sedlák J, Pánik M, Milata V. Pro-apoptotic effect of new quinolone 7- ethyl 9-ethyl-6-oxo-6,9-dihydro[1,2,5]selenadiazolo [3,4-h]quinoline-7-carboxylate on cervical cancer cell line HeLa alone/with UVA irradiation. Toxicol In Vitro 2016; 33:35-44. [DOI: 10.1016/j.tiv.2016.02.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Revised: 02/10/2016] [Accepted: 02/21/2016] [Indexed: 01/24/2023]
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4
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Jantová S, Melušová M, Pánik M, Brezová V, Barbieriková Z. UVA-induced effects of 2,6-disubstituted 4-anilinoquinazolines on cancer cell lines. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2016; 154:77-88. [DOI: 10.1016/j.jphotobiol.2015.11.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Revised: 11/02/2015] [Accepted: 11/05/2015] [Indexed: 10/22/2022]
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5
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Soldevila S, Cuquerella MC, Bosca F. Understanding of the Photoallergic Properties of Fluoroquinolones: Photoreactivity of Lomefloxacin with Amino Acids and Albumin. Chem Res Toxicol 2014; 27:514-23. [DOI: 10.1021/tx400377s] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- Sonia Soldevila
- Instituto
Universitario Mixto
de Tecnologia Quimica (UPV-CSIC), Universitat Politecnica de Valencia, Avenida de los Naranjos s/n, 46022 Valencia, Spain
| | - M. Consuelo Cuquerella
- Instituto
Universitario Mixto
de Tecnologia Quimica (UPV-CSIC), Universitat Politecnica de Valencia, Avenida de los Naranjos s/n, 46022 Valencia, Spain
| | - Francisco Bosca
- Instituto
Universitario Mixto
de Tecnologia Quimica (UPV-CSIC), Universitat Politecnica de Valencia, Avenida de los Naranjos s/n, 46022 Valencia, Spain
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6
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Soldevila S, Consuelo Cuquerella M, Lhiaubet-Vallet V, Edge R, Bosca F. Seeking the mechanism responsible for fluoroquinolone photomutagenicity: a pulse radiolysis, steady-state, and laser flash photolysis study. Free Radic Biol Med 2014; 67:417-25. [PMID: 24316197 DOI: 10.1016/j.freeradbiomed.2013.11.027] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2013] [Revised: 11/25/2013] [Accepted: 11/25/2013] [Indexed: 11/28/2022]
Abstract
The mechanism responsible for the remarkable photomutagenicity of fluoroquinolone (FQ) antibiotics remains unknown. For this reason, it was considered worthwhile to study in detail the interactions between DNA and a dihalogenated FQ such as lomefloxacin (LFX; one of the most photomutagenic FQs) and its N-acetyl derivative ALFX. Studies of photosensitized DNA damage by (A)LFX, such as formation of DNA single-strand breaks (SSBs), together with pulse radiolysis, laser flash photolysis, and absorption and fluorescence measurements, have shown the important effects of the cationic character of the piperazinyl ring on the affinity of this type of drug for DNA. Hence, the formation of SSBs was detected for LFX, whereas ALFX and ciprofloxacin (a monofluorated FQ) needed a considerably larger dose of light to produce some damage. In this context, it was determined that the association constant (Ka) for the binding of LFX to DNA is ca. 2×10(3)M(-1), whereas in the case of ALFX it is only ca. 0.5×10(3)M(-1). This important difference is attributed to an association between the cationic peripheral ring of LFX and the phosphate moieties of DNA and justifies the DNA SSB results. The analysis of the transient species detected and the photomixtures has allowed us to establish the intermolecular processes involved in the photolysis of FQ in the presence of DNA and 2'-deoxyguanosine (dGuo). Interestingly, although a covalent binding of the dihalogenated FQ to dGuo occurs, the photodegradation of FQ…DNA complexes did not reveal any significant covalent attachment. Another remarkable outcome of this study was that (A)LFX radical anions, intermediates required for the onset of DNA damage, were detected by pulse radiolysis but not by laser flash photolysis.
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Affiliation(s)
- Sonia Soldevila
- Instituto Universitario Mixto de Tecnologia Quimica (UPV-CSIC), Universitat Politecnica de Valencia, 46022 Valencia, Spain
| | - M Consuelo Cuquerella
- Instituto Universitario Mixto de Tecnologia Quimica (UPV-CSIC), Universitat Politecnica de Valencia, 46022 Valencia, Spain
| | - Virginie Lhiaubet-Vallet
- Instituto Universitario Mixto de Tecnologia Quimica (UPV-CSIC), Universitat Politecnica de Valencia, 46022 Valencia, Spain
| | - Ruth Edge
- Dalton Cumbrian Facility, The University of Manchester, Cumbria CA24 3HA, UK
| | - Francisco Bosca
- Instituto Universitario Mixto de Tecnologia Quimica (UPV-CSIC), Universitat Politecnica de Valencia, 46022 Valencia, Spain.
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7
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Yadav N, Dwivedi A, Mujtaba SF, Kushwaha HN, Singh SK, Ray RS. Ambient UVA-Induced Expression of p53 and Apoptosis in Human Skin Melanoma A375 Cell Line by Quinine. Photochem Photobiol 2013; 89:655-64. [DOI: 10.1111/php.12047] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2012] [Accepted: 01/08/2013] [Indexed: 11/28/2022]
Affiliation(s)
- Neera Yadav
- Photobiology Division; CSIR-Indian Institute of Toxicology Research; Lucknow; India
| | - Ashish Dwivedi
- Photobiology Division; CSIR-Indian Institute of Toxicology Research; Lucknow; India
| | - Syed Faiz Mujtaba
- Photobiology Division; CSIR-Indian Institute of Toxicology Research; Lucknow; India
| | - Hari Narayan Kushwaha
- Pharmacokinetics and Metabolism Division; CSIR-Central Drug Research Institute; Chhattar Manzil Palace; Lucknow; India
| | - Shio Kumar Singh
- Pharmacokinetics and Metabolism Division; CSIR-Central Drug Research Institute; Chhattar Manzil Palace; Lucknow; India
| | - Ratan Singh Ray
- Photobiology Division; CSIR-Indian Institute of Toxicology Research; Lucknow; India
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8
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Reus AA, Usta M, Kenny JD, Clements PJ, Pruimboom-Brees I, Aylott M, Lynch AM, Krul CA. The in vivo rat skin photomicronucleus assay: phototoxicity and photogenotoxicity evaluation of six fluoroquinolones. Mutagenesis 2012; 27:721-9. [DOI: 10.1093/mutage/ges038] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
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9
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Soldevila S, Bosca F. Photoreactivity of Fluoroquinolones: Nature of Aryl Cations Generated in Water. Org Lett 2012; 14:3940-3. [DOI: 10.1021/ol301694p] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Sonia Soldevila
- Instituto de Tecnología Química, Consejo Superior de Investigaciones Científicas/Universidad Politécnica de Valencia (CSIC/UPV), Avd. Los Naranjos s/n, 46022-Valencia, Spain
| | - Francisco Bosca
- Instituto de Tecnología Química, Consejo Superior de Investigaciones Científicas/Universidad Politécnica de Valencia (CSIC/UPV), Avd. Los Naranjos s/n, 46022-Valencia, Spain
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10
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Cuquerella MC, Andreu I, Soldevila S, Bosca F. Triplet Excimers of Fluoroquinolones in Aqueous Media. J Phys Chem A 2012; 116:5030-8. [DOI: 10.1021/jp301800q] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- M. Consuelo Cuquerella
- Instituto
de Tecnología Química, Consejo Superior de Investigaciones Científicas/Universidad Politécnica de Valencia (CSIC/UPV), Avd. Los
Naranjos s/n, 46022 Valencia, Spain
| | - Inmaculada Andreu
- Instituto
de Tecnología Química, Consejo Superior de Investigaciones Científicas/Universidad Politécnica de Valencia (CSIC/UPV), Avd. Los
Naranjos s/n, 46022 Valencia, Spain
| | - Sonia Soldevila
- Instituto
de Tecnología Química, Consejo Superior de Investigaciones Científicas/Universidad Politécnica de Valencia (CSIC/UPV), Avd. Los
Naranjos s/n, 46022 Valencia, Spain
| | - Francisco Bosca
- Instituto
de Tecnología Química, Consejo Superior de Investigaciones Científicas/Universidad Politécnica de Valencia (CSIC/UPV), Avd. Los
Naranjos s/n, 46022 Valencia, Spain
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11
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Yi YN, Li GR, Wang YS, Zhou YZ, Zhu HM. Simultaneous determination of norfloxacin and lomefloxacin in milk by first derivative synchronous fluorescence spectrometry using Al (III) as an enhancer. Anal Chim Acta 2011; 707:128-34. [DOI: 10.1016/j.aca.2011.09.029] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2011] [Revised: 09/18/2011] [Accepted: 09/20/2011] [Indexed: 11/30/2022]
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12
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Jantová S, Koňariková K, Letašiová S, Paulovičová E, Milata V, Brezová V. Photochemical and phototoxic properties of ethyl 1,4-dihydro-8-nitro-4-oxoquinoline-3-carboxylate, a new quinoline derivative. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2011; 102:77-91. [DOI: 10.1016/j.jphotobiol.2010.09.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2010] [Revised: 09/09/2010] [Accepted: 09/16/2010] [Indexed: 11/30/2022]
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13
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Reus AA, van Meeuwen RNC, de Vogel N, Maas WJM, Krul CAM. Development and characterisation of an in vitro photomicronucleus test using ex vivo human skin tissue. Mutagenesis 2010; 26:261-8. [DOI: 10.1093/mutage/geq056] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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14
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Development and characterization of an in vivo skin photomicronucleus assay in rats. Mutagenesis 2010; 25:407-16. [DOI: 10.1093/mutage/geq023] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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15
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Wu JH, Wilson JB, Wolfreys AM, Scott A, Jones NJ. Optimization of the comet assay for the sensitive detection of PUVA-induced DNA interstrand cross-links. Mutagenesis 2009; 24:173-81. [PMID: 19147795 DOI: 10.1093/mutage/gen068] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Psoralen plus ultraviolet A (PUVA), commonly used for the treatment of hyperproliferative skin disorders, has been found to be associated with an increased risk of squamous cell cancer. Interstrand cross-link (ICL) formation by PUVA treatment is considered the major factor contributing to the carcinogenesis. However, it remains unclear how PUVA causes, or promotes cancers, in humans. As an initial step in understanding the mechanisms of mutagenesis and carcinogenesis of PUVA photochemotherapy, we have optimized and subsequently utilized a modified alkaline comet assay involving a post-lysis gamma-irradiation at 9 Gy to sensitively measure the formation and repair of PUVA-induced ICLs in the immortalized human keratinocyte cell line HaCaT. A clear dose-dependent response of HaCaT cells to PUVA exposure was observed with a combination of a fixed UVA dose at 0.05 J/cm(2) and a dose of 8-methoxypsoralen ranging from 10 to 100 microM. Results also indicated that the ICL repair was concentration dependent. We have also demonstrated that PUVA-induced monoadduct formation, at an estimated ratio of 3:1 to ICLs in the present experimental conditions, does not interfere with the detection of the ICLs in the modified alkaline comet assay. Furthermore, comparison of the amount of ICL formation between the single-dose UVA treatment and a split-dose protocol was performed. The split-dose protocol was believed to generate more ICLs than the single-dose treatment, thus more effective in PUVA photochemotherapy. Our results demonstrate that comparable amounts of ICLs were formed in HaCaT cells for each dose of UVA, using either the split-dose or single-dose protocols.
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Affiliation(s)
- Jian H Wu
- Molecular Oncology Research Group, School of Biological Sciences, University of Liverpool, Liverpool, UK
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16
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Cuquerella MC, Miranda MA, Bosca F. Generation of Detectable Singlet Aryl Cations by Photodehalogenation of Fluoroquinolones. J Phys Chem B 2006; 110:6441-3. [PMID: 16570937 DOI: 10.1021/jp060634d] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Nanosecond laser flash photolysis (lambdaexc = 355 nm) of neutral aqueous solutions of lomefloxacin (LFX, a 8-fluorinated 7-amino-4-quinolone-3-carboxylic acid derivative) produces a detectable transient species, which shows an absorption maximum at 490 nm and can be assigned to an aryl cation. This intermediate has a lifetime of ca. 200 ns in net water, reacts with Br- and Cl- with rate constants of 3.6 x 10(9) M(-1) s(-1) and 4.1 x 10(8) M(-1) s(-1), respectively, and shows a lack of reactivity toward molecular oxygen. From the photolysis of BAY y3118 (BAY, a 8-chlorinated analogue), an aryl cation is also generated, showing absorption maximum at 480 nm (lifetime of ca. 1 micros in net water) and a reaction rate constant of 9 x 10(9) M(-1) s(-1) with Br(-). The existence of these highly reactive species arising from direct photolysis of LFX and BAY can justify the photogenotoxic properties associated with these antibacterial drugs likely due to direct reaction of their cations with DNA.
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Affiliation(s)
- M Consuelo Cuquerella
- Instituto de Technología Química UPV_CSIC, Universidad Politécnica de Valencia, Avda de los Naranjos s/n, 46022 Valencia, Spain
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17
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Humble MC, Trempus CS, Spalding JW, Cannon RE, Tennant RW. Biological, cellular, and molecular characteristics of an inducible transgenic skin tumor model: a review. Oncogene 2006; 24:8217-28. [PMID: 16355251 DOI: 10.1038/sj.onc.1209000] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The genetically initiated Tg.AC transgenic mouse carries a transgene consisting of an oncogenic v-Ha-ras coding region flanked 5' by a mouse zeta-globin promoter and 3' by an SV-40 polyadenylation sequence. Located on chromosome 11, the transgene is transcriptionally silent until activated by chemical carcinogens, UV light, or full-thickness wounding. Expression of the transgene is an early event that drives cellular proliferation resulting in clonal expansion and tumor formation, the unique characteristics now associated with the Tg.AC mouse. This ras-dependent phenotype has resulted in the widespread interest and use of the Tg.AC mouse in experimental skin carcinogenesis and as an alternative carcinogenesis assay. This review examines the general biology of the tumorigenic responses observed in Tg.AC mice, the genetic interactions of the ras transgene, and explores the cellular and molecular regulation of zeta-globin promoted transgene expression. As a prototype alternative model to the current long-term rodent bioassays, the Tg.AC has generated a healthy discussion on the future of transgenic bioassays, and opened the doors for subsequent models for toxicity testing. The further exploration and elucidation of the molecular controls of transgene expression will enhance the usefulness of this mouse and enable a better understanding of the Tg.AC's discriminate response to chemical carcinogens.
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Affiliation(s)
- Michael C Humble
- Curriculum in Toxicology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27514, USA
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