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Levina A, Crans DC, Lay PA. Speciation of metal drugs, supplements and toxins in media and bodily fluids controls in vitro activities. Coord Chem Rev 2017. [DOI: 10.1016/j.ccr.2017.01.002] [Citation(s) in RCA: 112] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/09/2022]
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2
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Thatoi HN, Pradhan SK. Detoxification and Bioremediation of Hexavalent Chromium Using Microbes and Their Genes: An Insight into Genomic, Proteomic and Bioinformatics Studies. Microb Biotechnol 2017. [DOI: 10.1007/978-981-10-6847-8_13] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
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3
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Spectroscopic characterization of genotoxic chromium(V) peptide complexes: Oxidation of Chromium(III) triglycine, tetraglycine and pentaglycine complexes. J Inorg Biochem 2016; 162:227-237. [DOI: 10.1016/j.jinorgbio.2016.06.015] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2015] [Revised: 06/07/2016] [Accepted: 06/14/2016] [Indexed: 11/23/2022]
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4
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Magro M, Domeneghetti S, Baratella D, Jakubec P, Salviulo G, Bonaiuto E, Venier P, Malina O, Tuček J, Ranc V, Zoppellaro G, Zbořil R, Vianello F. Colloidal Surface Active Maghemite Nanoparticles for Biologically Safe CrVI
Remediation: from Core-Shell Nanostructures to Pilot Plant Development. Chemistry 2016; 22:14219-26. [DOI: 10.1002/chem.201600544] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Indexed: 12/14/2022]
Affiliation(s)
- Massimiliano Magro
- Department of Comparative Biomedicine and Food Science; University of Padua; Legnaro 35020 Italy
- Department of Physical Chemistry; Faculty of Science; Regional Centre of Advanced Technologies and Materials; Palacky University in Olomouc; Olomouc 779 00 Czech Republic
| | | | - Davide Baratella
- Department of Comparative Biomedicine and Food Science; University of Padua; Legnaro 35020 Italy
| | - Petr Jakubec
- Department of Physical Chemistry; Faculty of Science; Regional Centre of Advanced Technologies and Materials; Palacky University in Olomouc; Olomouc 779 00 Czech Republic
| | | | - Emanuela Bonaiuto
- Department of Comparative Biomedicine and Food Science; University of Padua; Legnaro 35020 Italy
| | - Paola Venier
- Department of Biology; University of Padua; Padua 35121 Italy
| | - Ondřej Malina
- Department of Physical Chemistry; Faculty of Science; Regional Centre of Advanced Technologies and Materials; Palacky University in Olomouc; Olomouc 779 00 Czech Republic
| | - Jiří Tuček
- Department of Physical Chemistry; Faculty of Science; Regional Centre of Advanced Technologies and Materials; Palacky University in Olomouc; Olomouc 779 00 Czech Republic
| | - Václav Ranc
- Department of Physical Chemistry; Faculty of Science; Regional Centre of Advanced Technologies and Materials; Palacky University in Olomouc; Olomouc 779 00 Czech Republic
| | - Giorgio Zoppellaro
- Department of Physical Chemistry; Faculty of Science; Regional Centre of Advanced Technologies and Materials; Palacky University in Olomouc; Olomouc 779 00 Czech Republic
| | - Radek Zbořil
- Department of Physical Chemistry; Faculty of Science; Regional Centre of Advanced Technologies and Materials; Palacky University in Olomouc; Olomouc 779 00 Czech Republic
| | - Fabio Vianello
- Department of Comparative Biomedicine and Food Science; University of Padua; Legnaro 35020 Italy
- Department of Physical Chemistry; Faculty of Science; Regional Centre of Advanced Technologies and Materials; Palacky University in Olomouc; Olomouc 779 00 Czech Republic
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Wu LE, Levina A, Harris HH, Cai Z, Lai B, Vogt S, James DE, Lay PA. Carcinogenic Chromium(VI) Compounds Formed by Intracellular Oxidation of Chromium(III) Dietary Supplements by Adipocytes. Angew Chem Int Ed Engl 2015; 55:1742-5. [PMID: 26696553 DOI: 10.1002/anie.201509065] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2015] [Indexed: 12/31/2022]
Abstract
Chromium(III) nutritional supplements are widely consumed for their purported antidiabetic activities. X-ray fluorescence microscopy (XFM) and X-ray absorption near-edge structure (XANES) studies have now shown that non-toxic doses of [Cr3 O(OCOEt)6 (OH2 )3 ](+) (A), a prospective antidiabetic drug that undergoes similar H2 O2 induced oxidation reactions in the blood as other Cr supplements, was also oxidized to carcinogenic Cr(VI) and Cr(V) in living cells. Single adipocytes treated with A had approximately 1 μm large Cr hotspots containing Cr(III) , Cr(V) , and Cr(VI) (primarily Cr(VI) thiolates) species. These results strongly support the hypothesis that the antidiabetic activity of Cr(III) and the carcinogenicity of Cr(VI) compounds arise from similar mechanisms involving highly reactive Cr(VI) and Cr(V) intermediates, and highlight concerns over the safety of Cr(III) nutritional supplements.
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Affiliation(s)
- Lindsay E Wu
- School of Chemistry, The University of Sydney, NSW, 2006, Australia.,Garvan Institute of Medical Research, 384 Victoria St, Darlinghurst, NSW, 2010, Australia.,School of Medical Sciences, UNSW Australia, NSW, 2052, Australia
| | - Aviva Levina
- School of Chemistry, The University of Sydney, NSW, 2006, Australia
| | - Hugh H Harris
- School of Chemistry, The University of Sydney, NSW, 2006, Australia.,School of Chemistry and Physics, The University of Adelaide, SA, 5005, Australia
| | - Zhonghou Cai
- Advanced Photon Source, X-ray Science Division, Argonne National Laboratory, Argonne, IL, 60439, USA
| | - Barry Lai
- Advanced Photon Source, X-ray Science Division, Argonne National Laboratory, Argonne, IL, 60439, USA
| | - Stefan Vogt
- Advanced Photon Source, X-ray Science Division, Argonne National Laboratory, Argonne, IL, 60439, USA
| | - David E James
- Garvan Institute of Medical Research, 384 Victoria St, Darlinghurst, NSW, 2010, Australia.,Charles Perkins Centre, The University of Sydney, NSW, 2006, Australia
| | - Peter A Lay
- School of Chemistry, The University of Sydney, NSW, 2006, Australia.
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6
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Wu LE, Levina A, Harris HH, Cai Z, Lai B, Vogt S, James DE, Lay PA. Carcinogenic Chromium(VI) Compounds Formed by Intracellular Oxidation of Chromium(III) Dietary Supplements by Adipocytes. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201509065] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Lindsay E. Wu
- School of Chemistry; The University of Sydney; NSW 2006 Australia
- Garvan Institute of Medical Research; 384 Victoria St Darlinghurst NSW 2010 Australia
- School of Medical Sciences; UNSW Australia; NSW 2052 Australia
| | - Aviva Levina
- School of Chemistry; The University of Sydney; NSW 2006 Australia
| | - Hugh H. Harris
- School of Chemistry; The University of Sydney; NSW 2006 Australia
- School of Chemistry and Physics; The University of Adelaide; SA 5005 Australia
| | - Zhonghou Cai
- Advanced Photon Source; X-ray Science Division; Argonne National Laboratory; Argonne IL 60439 USA
| | - Barry Lai
- Advanced Photon Source; X-ray Science Division; Argonne National Laboratory; Argonne IL 60439 USA
| | - Stefan Vogt
- Advanced Photon Source; X-ray Science Division; Argonne National Laboratory; Argonne IL 60439 USA
| | - David E. James
- Garvan Institute of Medical Research; 384 Victoria St Darlinghurst NSW 2010 Australia
- Charles Perkins Centre; The University of Sydney; NSW 2006 Australia
| | - Peter A. Lay
- School of Chemistry; The University of Sydney; NSW 2006 Australia
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7
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Abstract
Chromium is ubiquitous in the environment as Cr(III) and Cr(VI) oxidation states, which interconvert under environmentally and biologically relevant conditions (although Cr(III) usually predominates). While Cr(VI) is an established human carcinogen and a major occupational and environmental hazard, Cr(III) has long been regarded as an essential human micronutrient, although recent literature has cast serious doubts on the validity of this postulate. Despite five decades of research, no functional Cr-containing enzymes or cofactors have been characterized conclusively, and several hypotheses on their possible structures have been refuted. Gastrointestinal absorption pathways for both Cr(III) and Cr(VI) are apparent and whole-blood speciation can involve Cr(VI) uptake and reduction by red blood cells, as well as Cr(III) binding to both proteins and low-molecular-mass ligands in the plasma. DNA-damaging effects of Cr(VI) and anti-diabetic activities of Cr(III) are likely to arise from common mechanistic pathways that involve reactive Cr(VI/V/IV) intermediates and kinetically inert Cr(III)-protein and Cr(III)-DNA adducts. Both Cr(III) and Cr(VI) are toxic to plants and microorganisms, particularly Cr(VI) due to its higher bioavailability and redox chemistry. Some bacteria reduce Cr(VI) to Cr(III) without the formation of toxic Cr(V) intermediates and these bacteria are being considered for use in the bioremediation of Cr(VI)-polluted environments.
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Affiliation(s)
- Peter A. Lay
- School of Chemistry, The University of Sydney Sydney NSW 2006 Australia
| | - Aviva Levina
- School of Chemistry, The University of Sydney Sydney NSW 2006 Australia
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8
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Scientific Opinion on the risks to public health related to the presence of chromium in food and drinking water. EFSA J 2014. [DOI: 10.2903/j.efsa.2014.3595] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
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9
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Viti C, Marchi E, Decorosi F, Giovannetti L. Molecular mechanisms of Cr(VI) resistance in bacteria and fungi. FEMS Microbiol Rev 2013; 38:633-59. [PMID: 24188101 DOI: 10.1111/1574-6976.12051] [Citation(s) in RCA: 155] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2013] [Revised: 09/13/2013] [Accepted: 10/28/2013] [Indexed: 11/28/2022] Open
Abstract
Hexavalent chromium [Cr(VI)] contamination is one of the main problems of environmental protection because the Cr(VI) is a hazard to human health. The Cr(VI) form is highly toxic, mutagenic, and carcinogenic, and it spreads widely beyond the site of initial contamination because of its mobility. Cr(VI), crossing the cellular membrane via the sulfate uptake pathway, generates active intermediates Cr(V) and/or Cr(IV), free radicals, and Cr(III) as the final product. Cr(III) affects DNA replication, causes mutagenesis, and alters the structure and activity of enzymes, reacting with their carboxyl and thiol groups. To persist in Cr(VI)-contaminated environments, microorganisms must have efficient systems to neutralize the negative effects of this form of chromium. The systems involve detoxification or repair strategies such as Cr(VI) efflux pumps, Cr(VI) reduction to Cr(III), and activation of enzymes involved in the ROS detoxifying processes, repair of DNA lesions, sulfur metabolism, and iron homeostasis. This review provides an overview of the processes involved in bacterial and fungal Cr(VI) resistance that have been identified through 'omics' studies. A comparative analysis of the described molecular mechanisms is offered and compared with the cellular evidences obtained using classical microbiological approaches.
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Affiliation(s)
- Carlo Viti
- Dipartimento di Scienze delle Produzioni Agroalimentari e dell'Ambiente - sezione di Microbiologia, Università degli Studi di Firenze, Florence, Italy
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10
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Hall MD, Daly HL, Zhang JZ, Zhang M, Alderden RA, Pursche D, Foran GJ, Hambley TW. Quantitative measurement of the reduction of platinum(IV) complexes using X-ray absorption near-edge spectroscopy (XANES). Metallomics 2012; 4:568-75. [PMID: 22569908 DOI: 10.1039/c2mt20053h] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The platinum(II) drugs cisplatin, carboplatin and oxaliplatin are usefully employed against a range of malignancies, but toxicities and resistance have spurred the search for improved analogs. This has included investigation of the platinum(IV) oxidation state, which provides greater kinetic inertness. It is generally accepted that Pt(IV) complexes must be reduced to Pt(II) for activation. As such, the ability to monitor reduction of Pt(IV) complexes is critical to guiding the design of candidates, and providing mechanistic understanding. Here we report in full that the white line height of X-ray absorption near-edge spectra (XANES) of Pt complexes, normalized to the post-edge minima, can be used to quantitatively determine the proportion of each oxidation state in a mixture. A series of Pt(IV) complexes based on the Pt(II) complexes cisplatin and transplatin were prepared with chlorido, acetato or hydroxido axial ligands, and studies into their reduction potential and cytotoxicity against A2780 human ovarian cancer cells were performed, demonstrating the relationship between reduction potential and cytotoxicity. Analysis of white line height demonstrated a clear and consistent difference between Pt(II) (1.52 ± 0.05) and Pt(IV) (2.43 ± 0.19) complexes. Reduction of Pt(IV) complexes over time in cell growth media and A2780 cells was observed by XANES, and shown to correspond with their reduction potentials and cytotoxicities. We propose that this method is useful for monitoring reduction of metal-based drug candidates in complex biological systems.
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Affiliation(s)
- Matthew D Hall
- Centre for Heavy Metals Research, School of Chemistry, The University of Sydney, NSW 2006, Australia
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11
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On the role of low-dose effects and epigenetics in toxicology. EXPERIENTIA SUPPLEMENTUM (2012) 2012; 101:499-550. [PMID: 22945581 DOI: 10.1007/978-3-7643-8340-4_18] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
For a long time, scientists considered genotoxic effects as the major issue concerning the influence of environmental chemicals on human health. Over the last decades, a new layer superimposed the genome, i.e., the epigenome, tremendously changing this point of view. The term "epigenetics" comprises stable alterations in gene expression potential arising from variations in DNA methylation and a variety of histone modifications, without changing the underlying DNA sequence. Recently, also gene silencing by small noncoding RNAs (ncRNAs), in particular by microRNAs, was included in the list of epigenetic mechanisms. Multiple studies in vivo as well as in vitro have shown that a multitude of different environmental factors are capable of changing the epigenetic pattern as well as miRNA expression in certain cell types, leading to aberrant gene expression profiles in cells and tissues. These changes may have extensive effects concerning the proper gene expression necessary in a specified cell type and can even lead into a state of disease. Especially the roles of epigenetic modifications and miRNA alterations in tumorigenesis have been a major focus in research over the last years. This chapter will give an overview on epigenetic features and on the spectrum of epigenetic changes observed after exposure against environmental chemicals and pollutants.
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12
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Dillon CT. Synchrotron Radiation Spectroscopic Techniques as Tools for the Medicinal Chemist: Microprobe X-Ray Fluorescence Imaging, X-Ray Absorption Spectroscopy, and Infrared Microspectroscopy. Aust J Chem 2012. [DOI: 10.1071/ch11287] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
This review updates the recent advances and applications of three prominent synchrotron radiation techniques, microprobe X-ray fluorescence spectroscopy/imaging, X-ray absorption spectroscopy, and infrared microspectroscopy, and highlights how these tools are useful to the medicinal chemist. A brief description of the principles of the techniques is given with emphasis on the advantages of using synchrotron radiation-based instrumentation rather than instruments using typical laboratory radiation sources. This review focuses on several recent applications of these techniques to solve inorganic medicinal chemistry problems, focusing on studies of cellular uptake, distribution, and biotransformation of established and potential therapeutic agents. The importance of using these synchrotron-based techniques to assist the development of, or validate the chemistry behind, drug design is discussed.
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Aitken JB, Carter EA, Eastgate H, Hackett MJ, Harris HH, Levina A, Lee YC, Chen CI, Lai B, Vogt S, Lay PA. Biomedical applications of X-ray absorption and vibrational spectroscopic microscopies in obtaining structural information from complex systems. Radiat Phys Chem Oxf Engl 1993 2010. [DOI: 10.1016/j.radphyschem.2009.03.068] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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14
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Synchrotron Infrared Spectromicroscopy for Studying Chemistry of Microbial Activity in Geologic Materials. SYNCHROTRON-BASED TECHNIQUES IN SOILS AND SEDIMENTS 2010. [DOI: 10.1016/s0166-2481(10)34004-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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15
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Synthesis, spectroscopic, structural and magnetic studies of new binary Cr(III)–citrate pH-specific structural variants from aqueous media. Polyhedron 2009. [DOI: 10.1016/j.poly.2009.05.077] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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16
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Guttmann D, Poage G, Johnston T, Zhitkovich A. Reduction with glutathione is a weakly mutagenic pathway in chromium(VI) metabolism. Chem Res Toxicol 2009; 21:2188-94. [PMID: 18808157 DOI: 10.1021/tx800265g] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Although reductive metabolism of Cr(VI) always results in the production of Cr(III) and extensive Cr-DNA binding, cellular studies have indicated that different reduction processes are not equivalent in the induction of mutagenic events. Here, we examined mutagenicity and formation of Cr-DNA damage by Cr(VI) activated in vitro by one of its important reducers, glutathione (GSH). Our main focus was on reactions containing 2 mM GSH, corresponding to its average concentration in CHO (1.8 mM) and V79 (2.6 mM) mutagenicity models. We found that Cr(VI) reduction by 2 mM GSH produced only weak mutagenic responses in pSP189 plasmids replicated in human fibroblasts. Reductive activation of Cr(VI) with 5 mM GSH resulted in approximately 4-times greater DNA adduct-normalized yield of mutations. Mutagenic DNA damage formed in GSH-chromate reactions was caused by nonoxidative mechanisms, as blocking of Cr-DNA adduction led to a complete loss of mutagenesis. All GSH-mediated reactions also lacked significant DNA single-strand breakage. We developed a sensitive HPLC procedure for the detection of GSH-Cr-DNA cross-links based on the dissociation of DNA-conjugated GSH by Cr(III) chelation and its derivatization with monobromobimane. Weak mutagenicity of 2 mM GSH reactions was associated with a low production of mutagenic GSH-Cr-DNA cross-links (5.0% of total Cr-DNA adducts). In agreement with their greater mutation-inducing ability, 5 mM GSH reactions generated 4-5 times higher levels of GSH-DNA cross-linking. Overall, our results indicate that chromate reduction by physiological concentrations of GSH is a weakly mutagenic process, which is consistent with low mutagenicity of Cr(VI) in ascorbate-deficient cells.
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Affiliation(s)
- David Guttmann
- Department of Pathology and Laboratory Medicine, Brown University, 70 Ship Street, Providence, Rhode Island 02912, USA
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17
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Carcinogenic metal compounds: recent insight into molecular and cellular mechanisms. Arch Toxicol 2008; 82:493-512. [PMID: 18496671 DOI: 10.1007/s00204-008-0313-y] [Citation(s) in RCA: 661] [Impact Index Per Article: 41.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2008] [Accepted: 04/30/2008] [Indexed: 02/07/2023]
Abstract
Mechanisms of carcinogenicity are discussed for metals and their compounds, classified as carcinogenic to humans or considered to be carcinogenic to humans: arsenic, antimony, beryllium, cadmium, chromium, cobalt, lead, nickel and vanadium. Physicochemical properties govern uptake, intracellular distribution and binding of metal compounds. Interactions with proteins (e.g., with zinc finger structures) appear to be more relevant for metal carcinogenicity than binding to DNA. In general, metal genotoxicity is caused by indirect mechanisms. In spite of diverse physicochemical properties of metal compounds, three predominant mechanisms emerge: (1) interference with cellular redox regulation and induction of oxidative stress, which may cause oxidative DNA damage or trigger signaling cascades leading to stimulation of cell growth; (2) inhibition of major DNA repair systems resulting in genomic instability and accumulation of critical mutations; (3) deregulation of cell proliferation by induction of signaling pathways or inactivation of growth controls such as tumor suppressor genes. In addition, specific metal compounds exhibit unique mechanisms such as interruption of cell-cell adhesion by cadmium, direct DNA binding of trivalent chromium, and interaction of vanadate with phosphate binding sites of protein phosphatases.
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Salnikow K, Zhitkovich A. Genetic and epigenetic mechanisms in metal carcinogenesis and cocarcinogenesis: nickel, arsenic, and chromium. Chem Res Toxicol 2008; 21:28-44. [PMID: 17970581 PMCID: PMC2602826 DOI: 10.1021/tx700198a] [Citation(s) in RCA: 554] [Impact Index Per Article: 34.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Chronic exposure to nickel(II), chromium(VI), or inorganic arsenic (iAs) has long been known to increase cancer incidence among affected individuals. Recent epidemiological studies have found that carcinogenic risks associated with chromate and iAs exposures were substantially higher than previously thought, which led to major revisions of the federal standards regulating ambient and drinking water levels. Genotoxic effects of Cr(VI) and iAs are strongly influenced by their intracellular metabolism, which creates several reactive intermediates and byproducts. Toxic metals are capable of potent and surprisingly selective activation of stress-signaling pathways, which are known to contribute to the development of human cancers. Depending on the metal, ascorbate (vitamin C) has been found to act either as a strong enhancer or suppressor of toxic responses in human cells. In addition to genetic damage via both oxidative and nonoxidative (DNA adducts) mechanisms, metals can also cause significant changes in DNA methylation and histone modifications, leading to epigenetic silencing or reactivation of gene expression. In vitro genotoxicity experiments and recent animal carcinogenicity studies provided strong support for the idea that metals can act as cocarcinogens in combination with nonmetal carcinogens. Cocarcinogenic and comutagenic effects of metals are likely to stem from their ability to interfere with DNA repair processes. Overall, metal carcinogenesis appears to require the formation of specific metal complexes, chromosomal damage, and activation of signal transduction pathways promoting survival and expansion of genetically/epigenetically altered cells.
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Affiliation(s)
- Konstantin Salnikow
- Konstantin Salnikow, National Cancer Institute, Bldg. 538, Room 205 E, Frederick, MD 21702, Phone: 301-846-5623, Fax: 301-846-5946, E-mail:
| | - Anatoly Zhitkovich
- Anatoly Zhitkovich, Brown University, Center for Genomics and Proteomics, Department of Pathology and Laboratory Medicine, 70 Ship Street, Providence RI 02912, Phone: 401-863-2912, Fax: 401-863-9008, E-mail:
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Levina A, Harris HH, Lay PA. X-ray absorption and EPR spectroscopic studies of the biotransformations of chromium(VI) in mammalian cells. Is chromodulin an artifact of isolation methods? J Am Chem Soc 2007; 129:1065-75. [PMID: 17263387 DOI: 10.1021/ja063792r] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Very different biological activities are usually ascribed to Cr(VI) (a toxin and carcinogen) and Cr(III) (an antidiabetic agent), although recent evidence suggests that both these types of actions are likely to arise from cellular uptake of varying concentrations of Cr(VI). The first systematic study of XANES spectra of Cr(III) complexes formed in Cr(VI)-treated mammalian cells (A549, HepG2, V79, and C2C12 cell lines), and in subcellular fractions of A549 cells, has been performed using a library of XANES spectra of model Cr(III) complexes. The results of multiple linear regression analyses of XANES spectra, in combination with multiple-scattering fits of XAFS spectra, indicate that Cr(III) formed in Cr(VI)-treated cells is most likely to bind to carboxylato, amine, and imidazole residues of amino acids, and to a lesser extent to hydroxo or aqua ligands. A combination of XANES and EPR spectroscopic data for Cr(VI)-treated cells indicates that the main component of Cr(III) formed in such cells is bound to high-molecular-mass ligands (>30 kDa, probably proteins), but significant redistribution of Cr(III) occurs during the cell lysis, which leads to the formation of a low-molecular-mass (<30 kDa) Cr(III)-containing fraction. The spectroscopic (XANES, XAFS, and EPR) properties of this fraction were strikingly similar to those of the purported natural Cr(III)-containing factor, chromodulin, that was reported to be isolated from the reaction of Cr(VI) with liver. These data support the hypothesis that a chromodulin-like species, which is formed from such a reaction, is an artifact of the reported isolation procedure.
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Affiliation(s)
- Aviva Levina
- Centre for Heavy Metals Research, School of Chemistry, The University of Sydney, NSW 2006, Australia
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Reynolds M, Stoddard L, Bespalov I, Zhitkovich A. Ascorbate acts as a highly potent inducer of chromate mutagenesis and clastogenesis: linkage to DNA breaks in G2 phase by mismatch repair. Nucleic Acids Res 2006; 35:465-76. [PMID: 17169990 PMCID: PMC1802609 DOI: 10.1093/nar/gkl1069] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Here we examined the role of cellular vitamin C in genotoxicity of carcinogenic chromium(VI) that requires reduction to induce DNA damage. In the presence of ascorbate (Asc), low 0.2–2 μM doses of Cr(VI) caused 10–15 times more chromosomal breakage in primary human bronchial epithelial cells or lung fibroblasts. DNA double-strand breaks (DSB) were preferentially generated in G2 phase as detected by colocalization of γH2AX and 53BP1 foci in cyclin B1-expressing cells. Asc dramatically increased the formation of centromere-negative micronuclei, demonstrating that induced DSB were inefficiently repaired. DSB in G2 cells were caused by aberrant mismatch repair of Cr damage in replicated DNA, as DNA polymerase inhibitor aphidicolin and silencing of MSH2 or MLH1 by shRNA suppressed induction of γH2AX and micronuclei. Cr(VI) was also up to 10 times more mutagenic in cells containing Asc. Increasing Asc concentrations generated progressively more mutations and DSB, revealing the genotoxic potential of otherwise nontoxic Cr(VI) doses. Asc amplified genotoxicity of Cr(VI) by altering the spectrum of DNA damage, as total Cr-DNA binding was unchanged and post-Cr loading of Asc exhibited no effects. Collectively, these studies demonstrated that Asc-dependent metabolism is the main source of genotoxic and mutagenic damage in Cr(VI)-exposed cells.
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Affiliation(s)
| | | | | | - Anatoly Zhitkovich
- To whom correspondence should be addressed. Tel: +1 401 863 2912; Fax: +1 401 863 9008;
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Bonnitcha PD, Hall MD, Underwood CK, Foran GJ, Zhang M, Beale PJ, Hambley TW. XANES investigation of the Co oxidation state in solution and in cancer cells treated with Co(III) complexes. J Inorg Biochem 2006; 100:963-71. [PMID: 16624414 DOI: 10.1016/j.jinorgbio.2006.02.015] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2005] [Revised: 02/16/2006] [Accepted: 02/16/2006] [Indexed: 11/30/2022]
Abstract
XANES spectroscopy has been used to investigate whether it is possible to determine the oxidation state and coordination environment of Co complexes following treatment of cancer cells with Co(III) or Co(II) complexes. Our results show that the variation of the XANES with coordination geometry make it impossible to do this in a completely reliable way which is in contrast to the situation for platinum and chromium. It was established that the XANES spectrum obtained from cells treated with [Co(diNOsar)]Br(3) remained unchanged with respect to its XANES spectrum obtained in solution, demonstrating that the [Co(diNOsar)]Br(3) complex remained intact after 24h in cellular media (diNOsar=1,8-dinitro-3,6,10,13,16,19-hexaazabicyclo[6.6.6]eicosane). In contrast, the XANES spectra obtained from cells treated with Na[Co(acac)(3)] and [Co(acac)(3)] differed from the XANES spectra of the respective complexes obtained in solution, indicating a change in co-ordination environment for both complexes upon uptake in cells. The similarity of these spectra suggests that appearance of this XANES can be used as an indication of loss of the carrier ligands, a useful indicator in the study of hypoxia selective complexes. The results obtained for Na[Co(acac)(3)] and [Co(acac)(3)] are consistent with the intracellular coordination of cobalt(III) to sulfur ligands upon cellular uptake.
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Affiliation(s)
- Paul D Bonnitcha
- Centre for Heavy Metals Research, School of Chemistry, University of Sydney, Sydney, NSW 2006, Australia
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Levina A, Harris HH, Lay PA. Binding of chromium(VI) to histones: implications for chromium(VI)-induced genotoxicity. J Biol Inorg Chem 2005; 11:225-34. [PMID: 16362419 DOI: 10.1007/s00775-005-0068-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2005] [Accepted: 11/23/2005] [Indexed: 10/25/2022]
Abstract
The first evidence has been obtained for Cr(VI) (chromate) binding to isolated calf thymus (CT) histones under physiological conditions (pH 7.4, Cl(-) concentration 152 mM, 310 K). No significant Cr(VI) binding under the same conditions was observed for other extracellular and intracellular proteins, including albumin, apo-transferrin and G-actin, as well as for CT DNA. The mode of Cr(VI) binding to histones was studied by vibrational, electronic and X-ray absorption (X-ray absorption near-edge structure and X-ray absorption fine structure) spectroscopies and molecular mechanics calculations. A proposed binding mechanism includes electrostatic interactions of CrO(4) (2-) with protonated Lys and Arg residues of histones, as well as the formation of hydrogen bonds with the protein backbone. Similarly, Cr(VI) can bind to nuclear localization signals (typically, Lys- and Arg-rich fragments) of other nuclear proteins. Selective binding of Cr(VI) to newly synthesized nuclear proteins (including histones) in the cytoplasm is likely to be responsible for the active transport of Cr(VI) into the nuclei of living cells.
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Affiliation(s)
- Aviva Levina
- Centre for Heavy Metals Research, and Centre for Structural Biology and Structural Chemistry, School of Chemistry, The University of Sydney, 2006 Sydney, NSW, Australia
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Harris HH, Levina A, Dillon CT, Mulyani I, Lai B, Cai Z, Lay PA. Time-dependent uptake, distribution and biotransformation of chromium(VI) in individual and bulk human lung cells: application of synchrotron radiation techniques. J Biol Inorg Chem 2005; 10:105-18. [PMID: 15714299 DOI: 10.1007/s00775-004-0617-1] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2004] [Accepted: 11/22/2004] [Indexed: 10/25/2022]
Abstract
Chromium(VI) is a human carcinogen, primarily affecting the respiratory tract probably via active transport into cells, followed by the reduction to Cr(III) with the formation of DNA-damaging intermediates. Distribution of Cr and endogenous elements within A549 human lung adenocarcinoma epithelial cells, following treatment with Cr(VI) (100 microM, 20 min or 4 h) were studied by synchrotron-radiation-induced X-ray emission (SRIXE) of single freeze-dried cells. After the 20-min treatment, Cr was confined to a small area of the cytoplasm and strongly co-localized with S, Cl, K, and Ca. After the 4-h treatment, Cr was distributed throughout the cell, with higher concentrations in the nucleus and the cytoplasmic membrane. This time-dependence corresponded to approximately 100% or 0% clonogenic survival of the cells following the 20-min or 4-h treatments, respectively, and could potentially be explained by a new cellular protective mechanism. Such processes may also be important in reducing the potential hazards of Cr(III) dietary supplements, for which there is emerging evidence that they exert their anti-diabetic effects via biological oxidation to Cr(VI). The predominance of Cr(III) was confirmed by micro-XANES spectroscopy of intracellular Cr hotspots. X-ray absorption spectroscopy (XANES and EXAFS, using freeze-dried cells after the 0-4-h treatments) was used to gain insight into the chemical structures of Cr(III) complexes formed during the intracellular reduction of Cr(VI). The polynuclear nature of such complexes (probably with a combination of carboxylato and hydroxo bridging groups and O-donor atoms of small peptides or proteins) was established by XAFS data analyses.
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Affiliation(s)
- Hugh H Harris
- Centre for Heavy Metals Research, and Centre for Structural Biology and Structural Chemistry, School of Chemistry, University of Sydney, NSW, Australia
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Levina A, Armstrong RS, Lay PA. Three-dimensional structure determination using multiple-scattering analysis of XAFS: applications to metalloproteins and coordination chemistry. Coord Chem Rev 2005. [DOI: 10.1016/j.ccr.2004.10.008] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Weeks CL, Levina A, Dillon CT, Turner P, Fenton RR, Lay PA. Synthesis and Characterization of a Chromium(V) cis-Dioxo Bis(1,10-phenanthroline) Complex and Crystal and Molecular Structures of Its Chromium(III) Precursor. Inorg Chem 2004; 43:7844-56. [PMID: 15554650 DOI: 10.1021/ic049008q] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The first structurally characterized Cr(V) dioxo complex, cis-[CrV(O)2(phen)2](BF4) (2, phen=1,10-phenanthroline) has been synthesized by the oxidation of a related Cr(III) complex, cis-[Cr(III)(phen)2(OH2)2](NO3)3.2.5H2O (1, characterized by X-ray crystallography), with NaOCl in aqueous solutions in the presence of excess NaBF4, and its purity has been confirmed by electrospray mass spectrometry (ESMS), EPR spectroscopy, and analytical techniques. Previously reported methods for the generation of Cr(V)-phen complexes, such as the oxidation of 1 with PbO2 or PhIO, have been shown by ESMS to lead to mixtures of Cr(III), Cr(V), Cr(VI), and in some cases Cr(IV) species, 3. Species 3 was assigned as [CrIV(O)(OH)(phen)2]+, based on ESMS and X-ray absorption spectroscopy measurements. A distorted octahedral structure for 2 (CrO, 1.63 A; Cr-N, 2.04 and 2.16 A) was established by multiple-scattering (MS) modeling of XAFS spectra (solid, 10 K). The validity of the model was verified by a good agreement between the results of MS XAFS fitting and X-ray crystallography for 1 (distorted octahedron; Cr-O, 1.95 A; Cr-N, 2.06 A). Unlike for the well-studied Cr(V) 2-hydroxycarboxylato complexes, 2 was equally or more stable in aqueous media (hours at pH=1-13 and 25 degrees C) compared with polar aprotic solvents. A stable Cr(III)-Cr(VI) dimer, [Cr(III)(Cr(VI)O4)(phen)2]+ (detected by ESMS), is formed during the decomposition of 2 in nonaqueous media. Comparative studies of the oxidation of 1 by NaOCl or PbO2 have shown that [Cr(V)(O)2(phen)2]+ was the active species responsible for the previously reported oxidative DNA damage, bacterial mutagenicity, and increased incidence of micronuclei in mammalian cells, caused by the oxidation products of 1 with PbO2. Efficient oxidation of 1 to a genotoxic species, [Cr(V)(O)2(phen)2]+, in neutral aqueous media by a biological oxidant, hypochlorite, supports the hypothesis on a significant role of reoxidation of Cr(III) complexes, formed during the intracellular reduction of Cr(VI), in Cr(VI)-induced carcinogenicity. Similar oxidation reactions may contribute to the reported adverse effects of a popular nutritional supplement, Cr(III) picolinate.
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Affiliation(s)
- Colin L Weeks
- Centre for Heavy Metals Research, School of Chemistry, University of Sydney, NSW 2006, Australia
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Levina A, Codd R, Foran GJ, Hambley TW, Maschmeyer T, Masters AF, Lay PA. X-ray Absorption Spectroscopic Studies of Chromium(V/IV/III)− 2-Ethyl-2-hydroxybutanoato(2−/1−) Complexes. Inorg Chem 2004; 43:1046-55. [PMID: 14753827 DOI: 10.1021/ic030239r] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Structures of the complexes [Cr(V)O(ehba)(2)](-), [Cr(IV)O(ehbaH)(2)](0), and [Cr(III)(ehbaH)(2)(OH(2))(2)](+) (ehbaH(2) = 2-ethyl-2-hydroxybutanoic acid) in frozen aqueous solutions (10 K, [Cr] = 10 mM, 1.0 M ehbaH(2)/ehbaH, pH 3.5) have been determined by single- and multiple-scattering fitting of X-ray absorption fine structure (XAFS) data. An optimal set of fitting parameters has been determined from the XAFS calculations for a compound with known crystal structure, Na[Cr(V)O(ehba)(2)] (solid, 10 K). The structure of the Cr(V) complex [Cr(V)O(ehba)(2)](-) does not change in solution in the presence of excess ligand. Contrary to the earlier suggestions made from the kinetic data (Ghosh, M. C.; Gould, E. S. J. Chem. Soc., Chem. Commun. 1992, 195-196), the structure of the Cr(IV) complex (generated by the Cr(VI) + As(III) + ehbaH(2) reaction) is close to that of the Cr(V) complex (five-coordinate, distorted trigonal bipyramidal) and different from that of the Cr(III) complex (six-coordinate, octahedral). For both Cr(V) and Cr(IV) complexes, some disorder in the position of the oxo group is observed, which is consistent with but not definitive for the presence of geometric isomers. The structure of the Cr(IV) complex differs from that of Cr(V) by protonation of alcoholato groups of the ligands, which leads to significant elongation of the corresponding Cr-O bonds (2.0 vs 1.8 A). This is reflected in the different chemical properties reported previously for the Cr(IV) and Cr(V) complexes, including their reactivities toward DNA and other biomolecules in relation to Cr-induced carcinogenicity.
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Affiliation(s)
- Aviva Levina
- Centre for Structural Biology and Structural Chemistry, School of Chemistry, University of Sydney, Sydney, NSW 2006, Australia
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Hall MD, Dillon CT, Zhang M, Beale P, Cai Z, Lai B, Stampfl APJ, Hambley TW. The cellular distribution and oxidation state of platinum(II) and platinum(IV) antitumour complexes in cancer cells. J Biol Inorg Chem 2003; 8:726-32. [PMID: 12884089 DOI: 10.1007/s00775-003-0471-6] [Citation(s) in RCA: 136] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2003] [Accepted: 05/21/2003] [Indexed: 11/28/2022]
Abstract
The cellular distribution of platinum in A2780 ovarian cancer cells treated with cisplatin and platinum(IV) complexes with a range of reduction potentials has been examined using elemental analysis (synchrotron radiation-induced X-ray emission). The cellular distribution of platinum(IV) drugs after 24 h is similar to that of cisplatin, consistent with the majority of administered platinum(IV) drugs being reduced. Micro-X-ray absorption near-edge spectra of cells treated with cisplatin and platinum(IV) complexes confirmed the reduction of platinum(IV) to platinum(II). In cells treated, the most difficult to reduce complex, cis, trans, cis-[PtCl(2)(OH)(2)(NH(3))(2)], platinum(IV) was detected in the cells along with platinum(II). The observations are in accordance with the relative ease of reduction of the platinum(IV) complexes used and support the requirement of reduction for activation of platinum(IV) complexes.
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Affiliation(s)
- Matthew D Hall
- Centre for Heavy Metals Research, School of Chemistry F11, The University of Sydney, 2006, N.S.W., Australia
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Levina A, Turner P, Lay PA. X-ray absorption spectroscopic studies of chromium nitroso complexes. Crystal and molecular structure of (Ph4P)3[Cr(NO)(NCS)5].2.4(CH3)2CO. Inorg Chem 2003; 42:5392-8. [PMID: 12924912 DOI: 10.1021/ic0340480] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
X-ray absorption spectroscopy (XAS) provides a direct means of solving the controversy on Cr oxidation states in nitroso complexes. The first XAS studies of four known Cr-NO complexes, [Cr(NO)(OH(2))(5)](2+), [Cr(NO)(acac)(2)(OH(2))], [Cr(NO)(CN)(5)](3)(-), and [Cr(NO)(NCS)(5)](3)(-), have been performed, in comparison with the related Cr(III) complexes, [Cr(OH(2))(6)](3+), [Cr(acac)(3)], [Cr(CN)(6)](3)(-), and [Cr(NCS)(6)](3)(-). The X-ray absorption near-edge structure (XANES) spectra of the Cr-NO complexes are distinguished from those of the corresponding Cr(III) complexes by increased intensities of pre-edge absorbancies due to the 1s --> 3d transition, as well as with slight shifts (by 0.2-1.0 eV) of the edge positions to lower energies, with no major changes in the edge shape. These features, together with the available structural data on Cr-NO complexes, show that the effective Cr oxidation states in such complexes are close to Cr(III), due to the pi-back-bonding within the Cr-NO moiety. Multiple-scattering fitting of X-ray absorption fine structure (XAFS) spectra of [Cr(NO)(acac)(2)(OH(2))] supported the assignment of this complex as a trans-isomer (Keller, A.; Jezovska-Trzebiatowska, B. Polyhedron 1985, 4, 1847-1852). The first crystal structure of a Cr nitroso-isothiocyanato complex, (Ph(4)P)(3)[Cr(NO)(NCS)(5)].2.4(CH(3))(2)CO, has been determined.
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Affiliation(s)
- Aviva Levina
- Centre for Heavy Metals Research, School of Chemistry, University of Sydney, Sydney, NSW 2006, Australia
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Majumder S, Ghoshal K, Summers D, Bai S, Datta J, Jacob ST. Chromium(VI) down-regulates heavy metal-induced metallothionein gene transcription by modifying transactivation potential of the key transcription factor, metal-responsive transcription factor 1. J Biol Chem 2003; 278:26216-26. [PMID: 12716893 PMCID: PMC2365495 DOI: 10.1074/jbc.m302887200] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The robust induction of metallothionein-I and II (MT-I and MT-II) genes by several heavy metals such as zinc and cadmium requires the specific transcription factor metal-responsive transcription factor 1 (MTF1). Chromium (VI), a major environmental carcinogen, not only failed to activate these genes but also inhibited their induction by Zn2+ or Cd2+. The heavy metal-induced expression of another MTF1 target gene, zinc transporter 1 (ZnT-1), was also down-regulated by Cr6+. By contrast, the expression of two MTF1-independent Cd2+-inducible genes, heme oxygenase 1 (HO-1) and HSP-70, was not sensitive to Cr6+. Cr6+ did not also affect the expression of housekeeping genes such as GAPDH or beta-actin. Stable cell lines overexpressing variable levels of MTF1, the key transactivator of the MT genes, demonstrated differential resistance toward the inhibitory effect of Cr6+, indicating MTF1 as a target of chromium toxicity. The basal and inducible binding of MTF1 to metal response elements was not affected by treatment of cells with Cr6+. Transient transfection studies showed that the ability of MTF1 to transactivate the MT-I promoter was significantly compromised by Cr6+. The fusion protein consisting of a Gal-4 DNA binding domain and one or more of the three transactivation domains of MTF1, namely the acidic domain, proline-rich domain, and serine-threonine rich domain, activated the GAL-4-driven luciferase gene to different degrees, but all were sensitive to Cr6+. MTF1 null cells were prone to apoptosis after exposure to Zn2+ or Cd2+ that was augmented in presence Cr6+, whereas the onset of apoptosis was significantly delayed in cells overexpressing MTF1.
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Affiliation(s)
- Sarmila Majumder
- Department of Molecular and Cellular Biochemistry, The Ohio State University, College of Medicine, The Ohio State University, Columbus, Ohio 43210, USA
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Hall MD, Foran GJ, Zhang M, Beale PJ, Hambley TW. XANES determination of the platinum oxidation state distribution in cancer cells treated with platinum(IV) anticancer agents. J Am Chem Soc 2003; 125:7524-5. [PMID: 12812486 DOI: 10.1021/ja0354770] [Citation(s) in RCA: 116] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Here we describe the use of X-ray absorption near edge spectroscopy (XANES) to provide information about the relative proportions of platinum(II) and platinum(IV) complexes by analyzing the XANES edge height. The intracellular reduction of platinum(IV) complexes in cancer cells has been observed directly, and the proportion of reduction after 2 h was found to correlate with the reduction potentials of the complexes.
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Affiliation(s)
- Matthew D Hall
- Centre for Heavy Metals Research, School of Chemistry, University of Sydney, Sydney, NSW 2006, Australia
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32
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Dayan AD, Paine AJ. Mechanisms of chromium toxicity, carcinogenicity and allergenicity: review of the literature from 1985 to 2000. Hum Exp Toxicol 2001; 20:439-51. [PMID: 11776406 DOI: 10.1191/096032701682693062] [Citation(s) in RCA: 448] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Laboratory and clinical reports about the pathogenesis of the carcinogenicity and allergenicity of chromium compounds published between 1985 and 2000 have been reviewed as a basis for consideration of the pathogenetic mechanisms involved. There is good evidence from the clinic and the laboratory that Cr[VI] is the ion responsible for most of the toxic actions, although much of the underlying molecular damage may be due to its intracellular reduction to the even more highly reactive and short-lived chemical species Cr[III] and Cr[V]. Exposure to Cr[VI] can result in various point mutations in DNA and to chromosomal damage, as well as to oxidative changes in proteins and to adduct formation. The relative importance of these effects of chromium ions and of the free oxidising radicals they may generate in the body in causing tumours and allergic sensitisation remain to be demonstrated. Biochemical studies of the DNA-damaging effects and of the pathogenesis of the allergic reactions to chromium ions have not kept up with advances in understanding of the molecular basis of the effects of other carcinogens and allergens.
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Affiliation(s)
- A D Dayan
- IRG in Toxicology, King's College London, UK
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ASAKURA H, IKEGAMI K, NAKAI Y, WAKITA H. Determination of components in alumina-chrome refractories by X-ray fluorescence spectrometry using glass beads. BUNSEKI KAGAKU 2000. [DOI: 10.2116/bunsekikagaku.49.735] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Hideo ASAKURA
- Research Center,Shinagawa Refractories Co.,Ltd.,707,Imbe,Bizen-shi,Okayama 705-8577
| | - Katsushige IKEGAMI
- Research Center,Shinagawa Refractories Co.,Ltd.,707,Imbe,Bizen-shi,Okayama 705-8577
| | - Yukari NAKAI
- Research Center,Shinagawa Refractories Co.,Ltd.,707,Imbe,Bizen-shi,Okayama 705-8577
| | - Hisanobu WAKITA
- Department of Chemistry,Faculty of Science,Fukuoka University,8-19-1,Nanakuma,Jonan-ku,Fukuoka 814-0133
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Ferreira ADQ, Bino A, Gibson D. Preparation, Structure and Stability of cis-{Cr(phen)(2)[OP(O)(OC(6)H(5))(2)](H(2)O)}(2+) as a Model for Cr(III)-DNA Adducts. Inorg Chem 1998; 37:6560-6561. [PMID: 11670785 DOI: 10.1021/ic981095x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Alba D. Q. Ferreira
- Department of Inorganic and Analytical Chemistry and Department of Pharmaceutical Chemistry, School of Pharmacy, The Hebrew University of Jerusalem, 91120 Jerusalem, Israel
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Lay PA, Levina A. Activation of Molecular Oxygen during the Reactions of Chromium(VI/V/IV) with Biological Reductants: Implications for Chromium-Induced Genotoxicities1. J Am Chem Soc 1998. [DOI: 10.1021/ja974240z] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Peter A. Lay
- Contribution from the School of Chemistry, University of Sydney, New South Wales 2006, Australia
| | - Aviva Levina
- Contribution from the School of Chemistry, University of Sydney, New South Wales 2006, Australia
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Voitkun V, Zhitkovich A, Costa M. Cr(III)-mediated crosslinks of glutathione or amino acids to the DNA phosphate backbone are mutagenic in human cells. Nucleic Acids Res 1998; 26:2024-30. [PMID: 9518499 PMCID: PMC147496 DOI: 10.1093/nar/26.8.2024] [Citation(s) in RCA: 116] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Carcinogenic Cr(VI) compounds were previously found to induce amino acid/glutathione-Cr(III)-DNA crosslinks with the site of adduction on the phosphate backbone. Utilizing the pSP189 shuttle vector plasmid we found that these ternary DNA adducts were mutagenic in human fibroblasts. The Cr(III)-glutathione adduct was the most potent in this assay, followed by Cr(III)-His and Cr(III)-Cys adducts. Binary Cr(III)-DNA complexes were only weakly mutagenic, inducing a significant response only at a 10 times higher number of adducts compared with Cr(III)-glutathione. Single base substitutions at the G:C base pairs were the predominant type of mutations for all Cr(III) adducts. Cr(III), Cr(III)-Cys and Cr(III)-His adducts induced G:C-->A:T transitions and G:C-->T:A transversions with almost equal frequency, whereas the Cr(III)-glutathione mutational spectrum was dominated by G:C-->T:A transversions. Adduct-induced mutations were targeted toward G:C base pairs with either A or G in the 3' position to the mutated G, while spontaneous mutations occurred mostly at G:C base pairs with a 3' A. No correlation was found between the sites of DNA adduction and positions of base substitution, as adducts were formed randomly on DNA with no base specificity. The observed mutagenicity of Cr(III)-induced phosphotriesters demonstrates the importance of a Cr(III)-dependent pathway in Cr(VI) carcinogenicity.
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Affiliation(s)
- V Voitkun
- Department of Environmental Medicine and The Kaplan Comprehensive Cancer Center, New York University Medical Center, 550 First Avenue, New York, NY 10016, USA
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Dillon CT, Lay PA, Bonin AM, Cholewa M, Legge GJ, Collins TJ, Kostka KL. Permeability, cytotoxicity, and genotoxicity of chromium (V) and chromium (VI) complexes in V79 Chinese hamster lung cells. Chem Res Toxicol 1998; 11:119-29. [PMID: 9511903 DOI: 10.1021/tx9701541] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The genotoxicity of Cr(V) complexes in mammalian cells (V79 Chinese hamster lung cells) has been studied for the first time using the in vitro micronucleus assay. Two complexes were investigated, [CrO(ehba)2]-, which undergoes ligand-exchange and disproportionation reactions in the cell growth medium, and [CrO(mampa)]-, which is chemically inert in the medium for the duration of the exposure period. Results of in vitro micronucleus assays show that both complexes are genotoxic and exhibit similar potencies to that of [Cr2O7]2-. The permeabilities of the Cr(V) complexes were also investigated for the first time using particle-induced X-ray emission (PIXE) analysis of individual cells. The Cr uptake increased in the order: [Cr(phen)2-(H2O)2]3+ < [CrO(ehba)2]- < [CrO(mampa)]- < [Cr2O7]2-. Clonal assays showed that Cr(VI) exhibits an expectedly higher cytotoxicity than the Cr(V) complexes. While the genotoxicities of the Cr(V) and Cr(VI) complexes increase according to their permeabilities, the genotoxicities of the Cr(V) complexes are equal to, if not greater than, that of Cr(VI) in terms of the amount of Cr entering the cell. This supports other evidence that Cr(V), produced as a metabolic intermediate from the intracellular reduction of Cr(VI), may be important in Cr-induced cancers.
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Affiliation(s)
- C T Dillon
- School of Chemistry, University of Sydney, NSW, Australia
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