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Maia LB, Maiti BK, Moura I, Moura JJG. Selenium-More than Just a Fortuitous Sulfur Substitute in Redox Biology. Molecules 2023; 29:120. [PMID: 38202704 PMCID: PMC10779653 DOI: 10.3390/molecules29010120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 12/19/2023] [Accepted: 12/20/2023] [Indexed: 01/12/2024] Open
Abstract
Living organisms use selenium mainly in the form of selenocysteine in the active site of oxidoreductases. Here, selenium's unique chemistry is believed to modulate the reaction mechanism and enhance the catalytic efficiency of specific enzymes in ways not achievable with a sulfur-containing cysteine. However, despite the fact that selenium/sulfur have different physicochemical properties, several selenoproteins have fully functional cysteine-containing homologues and some organisms do not use selenocysteine at all. In this review, selected selenocysteine-containing proteins will be discussed to showcase both situations: (i) selenium as an obligatory element for the protein's physiological function, and (ii) selenium presenting no clear advantage over sulfur (functional proteins with either selenium or sulfur). Selenium's physiological roles in antioxidant defence (to maintain cellular redox status/hinder oxidative stress), hormone metabolism, DNA synthesis, and repair (maintain genetic stability) will be also highlighted, as well as selenium's role in human health. Formate dehydrogenases, hydrogenases, glutathione peroxidases, thioredoxin reductases, and iodothyronine deiodinases will be herein featured.
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Affiliation(s)
- Luisa B. Maia
- LAQV, REQUIMTE, Department of Chemistry, NOVA School of Science and Technology | NOVA FCT, 2829-516 Caparica, Portugal; (I.M.); (J.J.G.M.)
| | - Biplab K. Maiti
- Department of Chemistry, School of Sciences, Cluster University of Jammu, Canal Road, Jammu 180001, India
| | - Isabel Moura
- LAQV, REQUIMTE, Department of Chemistry, NOVA School of Science and Technology | NOVA FCT, 2829-516 Caparica, Portugal; (I.M.); (J.J.G.M.)
| | - José J. G. Moura
- LAQV, REQUIMTE, Department of Chemistry, NOVA School of Science and Technology | NOVA FCT, 2829-516 Caparica, Portugal; (I.M.); (J.J.G.M.)
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2
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Jahankhani K, Taghipour N, Mashhadi Rafiee M, Nikoonezhad M, Mehdizadeh M, Mosaffa N. Therapeutic effect of trace elements on multiple myeloma and mechanisms of cancer process. Food Chem Toxicol 2023; 179:113983. [PMID: 37567355 DOI: 10.1016/j.fct.2023.113983] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Revised: 07/09/2023] [Accepted: 08/07/2023] [Indexed: 08/13/2023]
Abstract
In the human body, trace elements and other micronutrients play a vital role in growth, health and immune system function. The trace elements are Iron, Manganese, Copper, Iodine, Zinc, Cobalt, Fluoride, and Selenium. Estimating the serum levels of trace elements in hematologic malignancy patients can determine the severity of the tumor. Multiple myeloma (MM) is a hematopoietic malignancy and is characterized by plasma cell clonal expansion in bone marrow. Despite the advances in treatment methods, myeloma remains largely incurable. In addition to conventional medicine, treatment is moving toward less expensive noninvasive alternatives. One of the alternative treatments is the use of dietary supplements. In this review, we focused on the effect of three trace elements including iron, zinc and selenium on important mechanisms such as the immune system, oxidative and antioxidant factors and cell cycle. Using some trace minerals in combination with approved drugs can increase patients' recovery speed. Trace elements can be used as not only a preventive but also a therapeutic tool, especially in reducing inflammation in hematological cancers such as multiple myeloma. We hope that the prospect of the correct use of trace element supplements in the future could be promising for the treatment of diseases.
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Affiliation(s)
- Kasra Jahankhani
- Department of Immunology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Niloofar Taghipour
- Medical Nanotechnology and Tissue Engineering Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran; Department of Tissue Engineering and Applied Cell Sciences, School of Advanced Technologies in Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | | | - Maryam Nikoonezhad
- Department of Immunology, School of Medicine, Tarbiat Modarres University, Tehran, Iran
| | - Mahshid Mehdizadeh
- Hematopoietic Stem Cell Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Nariman Mosaffa
- Department of Immunology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
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3
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Kieliszek M, Bano I, Zare H. A Comprehensive Review on Selenium and Its Effects on Human Health and Distribution in Middle Eastern Countries. Biol Trace Elem Res 2022; 200:971-987. [PMID: 33884538 PMCID: PMC8761138 DOI: 10.1007/s12011-021-02716-z] [Citation(s) in RCA: 61] [Impact Index Per Article: 30.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Accepted: 04/08/2021] [Indexed: 12/16/2022]
Abstract
Selenium (Se) is an important microelement with numerous positive effects on human health and diseases. It is important to specify that the status and consumption of Se are for a specific community as the levels of Se are extremely unpredictable between different populations and regions. Our existing paper was based on the impacts of Se on human health and disease along with data on the Se levels in Middle Eastern countries. Overall, the findings of this comprehensive review show that the consumption and levels of Se are inadequate in Middle Eastern nations. Such findings, together with the growing awareness of the importance of Se to general health, require further work primarily on creating an acceptable range of blood Se concentration or other measures to determine optimal Se consumption and, consequently, to guarantee adequate Se supplementation in populations at high risk of low Se intake.
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Affiliation(s)
- Marek Kieliszek
- Department of Food Biotechnology and Microbiology, Institute of Food Sciences, Warsaw University of Life Sciences-SGGW, Nowoursynowska 159C, 02-776 Warsaw, Poland
| | - Iqra Bano
- Department of Veterinary Physiology and Biochemistry, Shaheed Benazir Bhutto University of Veterinary & Animal Sciences Sakrand, Sindh, 67210 Pakistan
| | - Hamed Zare
- Cellular and Molecular Research Center, Birjand University of Medical Sciences, Birjand, Iran
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4
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Wolff L, Bandaru SSM, Eger E, Lam HN, Napierkowski M, Baecker D, Schulzke C, Bednarski PJ. Comprehensive Evaluation of Biological Effects of Pentathiepins on Various Human Cancer Cell Lines and Insights into Their Mode of Action. Int J Mol Sci 2021; 22:ijms22147631. [PMID: 34299253 PMCID: PMC8305076 DOI: 10.3390/ijms22147631] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 07/06/2021] [Accepted: 07/08/2021] [Indexed: 12/20/2022] Open
Abstract
Pentathiepins are polysulfur-containing compounds that exert antiproliferative and cytotoxic activity in cancer cells, induce oxidative stress and apoptosis, and inhibit glutathione peroxidase (GPx1). This renders them promising candidates for anticancer drug development. However, the biological effects and how they intertwine have not yet been systematically assessed in diverse cancer cell lines. In this study, six novel pentathiepins were synthesized to suit particular requirements such as fluorescent properties or improved water solubility. Structural elucidation by X-ray crystallography was successful for three derivatives. All six underwent extensive biological evaluation in 14 human cancer cell lines. These studies included investigating the inhibition of GPx1 and cell proliferation, cytotoxicity, and the induction of ROS and DNA strand breaks. Furthermore, selected hallmarks of apoptosis and the impact on cell cycle progression were studied. All six pentathiepins exerted high cytotoxic and antiproliferative activity, while five also strongly inhibited GPx1. There is a clear connection between the potential to provoke oxidative stress and damage to DNA in the form of single- and double-strand breaks. Additionally, these studies support apoptosis but not ferroptosis as the mechanism of cell death in some of the cell lines. As the various pentathiepins give rise to different biological responses, modulation of the biological effects depends on the distinct chemical structures fused to the sulfur ring. This may allow for an optimization of the anticancer activity of pentathiepins in the future.
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Affiliation(s)
- Lisa Wolff
- Pharmazeutische/Medizinische Chemie, Institut für Pharmazie, Universität Greifswald, 17489 Greifswald, Germany; (L.W.); (H.-N.L.); (M.N.); (D.B.)
| | | | - Elias Eger
- Pharmazeutische Mikrobiologie, Institut für Pharmazie, Universität Greifswald, 17489 Greifswald, Germany;
| | - Hoai-Nhi Lam
- Pharmazeutische/Medizinische Chemie, Institut für Pharmazie, Universität Greifswald, 17489 Greifswald, Germany; (L.W.); (H.-N.L.); (M.N.); (D.B.)
| | - Martin Napierkowski
- Pharmazeutische/Medizinische Chemie, Institut für Pharmazie, Universität Greifswald, 17489 Greifswald, Germany; (L.W.); (H.-N.L.); (M.N.); (D.B.)
| | - Daniel Baecker
- Pharmazeutische/Medizinische Chemie, Institut für Pharmazie, Universität Greifswald, 17489 Greifswald, Germany; (L.W.); (H.-N.L.); (M.N.); (D.B.)
| | - Carola Schulzke
- Bioanorganische Chemie, Institut für Biochemie, Universität Greifswald, 17489 Greifswald, Germany;
- Correspondence: (C.S.); (P.J.B.); Tel.: +49-3834-420-4321 (C.S.); +49-3834-420-4883 (P.J.B.)
| | - Patrick J. Bednarski
- Pharmazeutische/Medizinische Chemie, Institut für Pharmazie, Universität Greifswald, 17489 Greifswald, Germany; (L.W.); (H.-N.L.); (M.N.); (D.B.)
- Correspondence: (C.S.); (P.J.B.); Tel.: +49-3834-420-4321 (C.S.); +49-3834-420-4883 (P.J.B.)
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5
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Lu J, Wei N, Cao J, Zhou Y, Gong H, Zhang H, Zhou J. Evaluation of enzymatic activity of Babesia microti thioredoxin reductase (Bmi TrxR)-mutants and screening of its potential inhibitors. Ticks Tick Borne Dis 2020; 12:101623. [PMID: 33418338 DOI: 10.1016/j.ttbdis.2020.101623] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Revised: 12/07/2020] [Accepted: 12/08/2020] [Indexed: 01/25/2023]
Abstract
Babesia microti is a zoonotic pathogen that mainly parasitizes mammalian erythrocytes. Oxidative stress can induce gene mutation, protein denaturation and lipid peroxidation, such as reactive oxygen species (ROS) induced by hypoxic environment and the host immune system. An antioxidase, B. microti thioredoxin reductase (Bmi TrxR), has been identified in B. microti. We used a combination of homology modeling and domain prediction to explore the functional sites of Bmi TrxR and found that TrxR has three domains. Constructed a mutant pool which His-tag were at the N-terminus (TrxR-Nhis, C105-Nhis, C110-Nhis, C105110-Nhis, C547-Nhis, C552-Nhis, C547552-Nhis) and the His tag were at the N- and C-terminus (TrxR-NChis, C547-NChis, C552-NChis, C547552-NChis). The proteins were expressed as His-tagged fusion proteins in Escherichia coli. The His-tag of TrxR C-terminus were affected the reaction with Trx. The inhibitory efficiency of DNCB was decreased for mutant C547, compared with recombinant TrxR, indicating that the action site of DNCB might be cysteine at position 547. These results indicate that the N-terminal active site of Bmi TrxR plays an important role in accepting electrons and promotes electron transfer. The C-terminus His tag of Bmi TrxR affected the electron transfer and the reducing activity of Bmi TrxR. Reduce reactive oxygen produced in oxidative stress was reduced by Bmi TrxR, which is beneficial to Babesia survival. Therefore, reduction site of TrxR may become a potential target for Babesia microti treatment.
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Affiliation(s)
- Jinmiao Lu
- Key Laboratory of Animal Parasitology of Ministry of Agriculture, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai 200241, China
| | - Nana Wei
- Key Laboratory of Animal Parasitology of Ministry of Agriculture, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai 200241, China
| | - Jie Cao
- Key Laboratory of Animal Parasitology of Ministry of Agriculture, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai 200241, China
| | - Yongzhi Zhou
- Key Laboratory of Animal Parasitology of Ministry of Agriculture, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai 200241, China
| | - Haiyan Gong
- Key Laboratory of Animal Parasitology of Ministry of Agriculture, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai 200241, China
| | - Houshuang Zhang
- Key Laboratory of Animal Parasitology of Ministry of Agriculture, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai 200241, China.
| | - Jinlin Zhou
- Key Laboratory of Animal Parasitology of Ministry of Agriculture, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai 200241, China.
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6
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Stolwijk JM, Garje R, Sieren JC, Buettner GR, Zakharia Y. Understanding the Redox Biology of Selenium in the Search of Targeted Cancer Therapies. Antioxidants (Basel) 2020; 9:E420. [PMID: 32414091 PMCID: PMC7278812 DOI: 10.3390/antiox9050420] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Revised: 04/24/2020] [Accepted: 05/10/2020] [Indexed: 12/18/2022] Open
Abstract
Selenium (Se) is an essential trace nutrient required for optimal human health. It has long been suggested that selenium has anti-cancer properties. However, clinical trials have shown inconclusive results on the potential of Se to prevent cancer. The suggested role of Se in the prevention of cancer is centered around its role as an antioxidant. Recently, the potential of selenium as a drug rather than a supplement has been uncovered. Selenium compounds can generate reactive oxygen species that could enhance the treatment of cancer. Transformed cells have high oxidative distress. As normal cells have a greater capacity to meet oxidative challenges than tumor cells, increasing the flux of oxidants with high dose selenium treatment could result in cancer-specific cell killing. If the availability of Se is limited, supplementation of Se can increase the expression and activities of Se-dependent proteins and enzymes. In cell culture, selenium deficiency is often overlooked. We review the importance of achieving normal selenium biology and how Se deficiency can lead to adverse effects. We examine the vital role of selenium in the prevention and treatment of cancer. Finally, we examine the properties of Se-compounds to better understand how each can be used to address different research questions.
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Affiliation(s)
- Jeffrey M. Stolwijk
- Interdisciplinary Graduate Program in Human Toxicology, The University of Iowa, Iowa City, IA 52242, USA;
| | - Rohan Garje
- Department of Internal Medicine, Division of Medical Oncology and Hematology, The University of Iowa Hospital and Clinics—Holden Comprehensive Cancer Center, Iowa City, IA 52242, USA;
| | - Jessica C. Sieren
- Departments of Radiology and Biomedical Engineering, The University of Iowa, Iowa City, IA 52242, USA;
| | - Garry R. Buettner
- Interdisciplinary Graduate Program in Human Toxicology, The University of Iowa, Iowa City, IA 52242, USA;
- Free Radical and Radiation Biology Program, Department of Radiation Oncology, The University of Iowa, Iowa City, IA 52242, USA
| | - Yousef Zakharia
- Department of Internal Medicine, Division of Medical Oncology and Hematology, The University of Iowa Hospital and Clinics—Holden Comprehensive Cancer Center, Iowa City, IA 52242, USA;
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7
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Stolwijk JM, Falls-Hubert KC, Searby CC, Wagner BA, Buettner GR. Simultaneous detection of the enzyme activities of GPx1 and GPx4 guide optimization of selenium in cell biological experiments. Redox Biol 2020; 32:101518. [PMID: 32278283 PMCID: PMC7150527 DOI: 10.1016/j.redox.2020.101518] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 03/14/2020] [Accepted: 03/21/2020] [Indexed: 12/29/2022] Open
Abstract
Selenium is a metalloid trace element essential for maintaining the optimal redox environment in cells and tissues. It is structurally incorporated into over 25 selenoproteins and enzymes. The glutathione peroxidase (GPx) family of enzymes has a critical role in human health because of its antioxidant function. The recommended daily allowance (RDA) for selenium intake in humans was established to maximize the activity of GPx in plasma. Suboptimal availability of selenium can limit the expression and activities of GPxs leading to a compromised redox environment. This can cause detrimental oxidative distress that could be prevented by increasing the availability of selenium. In cell culture studies, the medium is typically deficient in selenium; supplementation with selenium can increase selenoenzyme activities. However, the optimal level of supplementation in cell culture media has not been well characterized. We performed dose-response experiments for the activities of GPx1 and GPx4 vs. the level of selenium supplementation in cell culture medium. For this, we advanced an assay to determine the activities of both GPx1 and GPx4 efficiently in a single run. During the optimization process, we found that the observed activities of GPx1 and GPx4 depend greatly on the pH of the assay buffer; the observed activities increase with increasing pH, with pH 8 being optimal. Using the combination assay, we also found that the expression and activities for both GPx1 and GPx4 can be maximized in exponentially growing cells by supplementing cell culture media with ≈ 200 nM seleno-l-methionine, without concerns for toxicity. Optimizing the availability of selenium in cell culture to maximize the expression and activities GPx1 and GPx4 may allow for better translation of information from cell culture work to in vivo settings.
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Affiliation(s)
- Jeffrey M Stolwijk
- Interdisciplinary Graduate Program in Human Toxicology, The University of Iowa, Iowa City, IA, 52242, USA
| | - Kelly C Falls-Hubert
- Free Radical and Radiation Biology Program, Department of Radiation Oncology, The University of Iowa, Iowa City, IA, 52242, USA
| | - Charles C Searby
- Department of Pediatrics, The University of Iowa, Iowa City, IA, 52242, USA
| | - Brett A Wagner
- Free Radical and Radiation Biology Program, Department of Radiation Oncology, The University of Iowa, Iowa City, IA, 52242, USA
| | - Garry R Buettner
- Interdisciplinary Graduate Program in Human Toxicology, The University of Iowa, Iowa City, IA, 52242, USA; Free Radical and Radiation Biology Program, Department of Radiation Oncology, The University of Iowa, Iowa City, IA, 52242, USA.
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8
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Jovanović M, Zhukovsky D, Podolski-Renić A, Žalubovskis R, Dar'in D, Sharoyko V, Tennikova T, Pešić M, Krasavin M. Further exploration of DVD-445 as a lead thioredoxin reductase (TrxR) inhibitor for cancer therapy: Optimization of potency and evaluation of anticancer potential. Eur J Med Chem 2020; 191:112119. [PMID: 32087464 DOI: 10.1016/j.ejmech.2020.112119] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2020] [Revised: 01/29/2020] [Accepted: 02/03/2020] [Indexed: 02/06/2023]
Abstract
A series of analogs of the earlier reported lead compound DVD-445 (thioredoxin reductase inhibitor with anticancer activity) has been synthesized via a modified Ugi reaction and investigated. Seven most potent compounds (with IC50 below 5.00 μM against recombinant rTrxR1 enzyme) were examined for their effect on cell growth and viability, oxidative stress induction and P-glycoprotein (P-gp) inhibition in human glioblastoma cells cell line U87 and its corresponding multidrug resistant (MDR) cell line U87-TxR. Several of these frontrunner compounds were shown to be superior over DVD-445. Besides providing promising candidates for anticancer therapy, our study further validates the small electrophilic Ugi Michael acceptor (UMA) chemotype as efficacious inhibitor of thioredoxin reductase.
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Affiliation(s)
- Mirna Jovanović
- Institute for Biological Research "Siniša Stanković" - National Institute of Republic of Serbia, University of Belgrade, 11060, Belgrade, Serbia
| | - Daniil Zhukovsky
- Saint Petersburg State University, Saint Petersburg, 199034, Russian Federation
| | - Ana Podolski-Renić
- Institute for Biological Research "Siniša Stanković" - National Institute of Republic of Serbia, University of Belgrade, 11060, Belgrade, Serbia
| | - Raivis Žalubovskis
- Latvian Institute of Organic Synthesis, Riga, LV-1006, Latvia; Institute of Technology of Organic Chemistry, Faculty of Materials Science and Applied Chemistry, Riga Technical University, Riga, LV-1048, Latvia
| | - Dmitry Dar'in
- Saint Petersburg State University, Saint Petersburg, 199034, Russian Federation
| | - Vladimir Sharoyko
- Saint Petersburg State University, Saint Petersburg, 199034, Russian Federation
| | - Tatiana Tennikova
- Saint Petersburg State University, Saint Petersburg, 199034, Russian Federation
| | - Milica Pešić
- Institute for Biological Research "Siniša Stanković" - National Institute of Republic of Serbia, University of Belgrade, 11060, Belgrade, Serbia.
| | - Mikhail Krasavin
- Saint Petersburg State University, Saint Petersburg, 199034, Russian Federation.
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9
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Jovanović M, Zhukovsky D, Podolski-Renić A, Domračeva I, Žalubovskis R, Senćanski M, Glišić S, Sharoyko V, Tennikova T, Dar'in D, Pešić M, Krasavin M. Novel electrophilic amides amenable by the Ugi reaction perturb thioredoxin system via thioredoxin reductase 1 (TrxR1) inhibition: Identification of DVD-445 as a new lead compound for anticancer therapy. Eur J Med Chem 2019; 181:111580. [PMID: 31400708 DOI: 10.1016/j.ejmech.2019.111580] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2019] [Revised: 07/30/2019] [Accepted: 07/31/2019] [Indexed: 12/13/2022]
Abstract
A series of peptidomimetic compounds incorporating an electrophilic moiety was synthesized using the Ugi reaction. These compounds (termed the Ugi Michael acceptors or UMAs) were designed to target the selenocysteine catalytic residue of thioredoxin reductase 1 (TrxR1), a promising cancer target. The compounds were assessed for their potential to inhibit TrxR1 using human neuroblastoma (SH-SY5Y) cell lysate. Based on this initial screening, six compounds were selected for testing against recombinant rat TrxR1 and in the insulin assay to reveal low-micromolar to submicromolar potency of these inhibitors. The same frontrunner compounds were evaluated for their ability to exert antiproliferative activity and induce cell death and this activity was compared to the UMA effects on the levels of reactive oxygen and nitrogen species (RONS). Collectively, the UMA compounds class presented itself as a rich source of leads for TrxR1 inhibitor discovery for anticancer application. Compound 7 (DVD-445) was nominated a lead for further optimization.
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Affiliation(s)
- Mirna Jovanović
- Institute for Biological Research "Siniša Stanković", University of Belgrade, 11060, Belgrade, Serbia
| | - Daniil Zhukovsky
- Saint Petersburg State University, Saint Petersburg, 199034, Russian Federation
| | - Ana Podolski-Renić
- Institute for Biological Research "Siniša Stanković", University of Belgrade, 11060, Belgrade, Serbia
| | - Ilona Domračeva
- Latvian Institute of Organic Synthesis, Riga, LV-1006, Latvia
| | - Raivis Žalubovskis
- Latvian Institute of Organic Synthesis, Riga, LV-1006, Latvia; Institute of Technology of Organic Chemistry, Faculty of Materials Science and Applied Chemistry, Riga Technical University, Riga, LV-1048, Latvia
| | - Milan Senćanski
- Laboratory for Bioinformatics and Computational Chemistry, Institute of Nuclear Sciences VINCA, University of Belgrade, P.O. Box 522, 11001, Belgrade, Serbia
| | - Sanja Glišić
- Laboratory for Bioinformatics and Computational Chemistry, Institute of Nuclear Sciences VINCA, University of Belgrade, P.O. Box 522, 11001, Belgrade, Serbia
| | - Vladimir Sharoyko
- Saint Petersburg State University, Saint Petersburg, 199034, Russian Federation
| | - Tatiana Tennikova
- Saint Petersburg State University, Saint Petersburg, 199034, Russian Federation
| | - Dmitry Dar'in
- Saint Petersburg State University, Saint Petersburg, 199034, Russian Federation
| | - Milica Pešić
- Institute for Biological Research "Siniša Stanković", University of Belgrade, 11060, Belgrade, Serbia.
| | - Mikhail Krasavin
- Saint Petersburg State University, Saint Petersburg, 199034, Russian Federation.
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10
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Peters KM, Carlson BA, Gladyshev VN, Tsuji PA. Selenoproteins in colon cancer. Free Radic Biol Med 2018; 127:14-25. [PMID: 29793041 PMCID: PMC6168369 DOI: 10.1016/j.freeradbiomed.2018.05.075] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Revised: 05/18/2018] [Accepted: 05/20/2018] [Indexed: 02/07/2023]
Abstract
Selenocysteine-containing proteins (selenoproteins) have been implicated in the regulation of various cell signaling pathways, many of which are linked to colorectal malignancies. In this in-depth excurse into the selenoprotein literature, we review possible roles for human selenoproteins in colorectal cancer, focusing on the typical hallmarks of cancer cells and their tumor-enabling characteristics. Human genome studies of single nucleotide polymorphisms in various genes coding for selenoproteins have revealed potential involvement of glutathione peroxidases, thioredoxin reductases, and other proteins. Cell culture studies with targeted down-regulation of selenoproteins and studies utilizing knockout/transgenic animal models have helped elucidate the potential roles of individual selenoproteins in this malignancy. Those selenoproteins, for which strong links to development or progression of colorectal cancer have been described, may be potential future targets for clinical interventions.
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Affiliation(s)
- Kristin M Peters
- Dept. of Biological Sciences, Towson University, 8000 York Rd, Towson, MD 21252, United States.
| | - Bradley A Carlson
- National Cancer Institute, National Institutes of Health, 9000 Rockville Pike, Bethesda, MD 20892, United States.
| | - Vadim N Gladyshev
- Dept. of Medicine, Brigham & Women's Hospital, Harvard Medical School, 77 Avenue Louis Pasteur, Boston, MA 02115, United States.
| | - Petra A Tsuji
- Dept. of Biological Sciences, Towson University, 8000 York Rd, Towson, MD 21252, United States.
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11
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Zoidis E, Seremelis I, Kontopoulos N, Danezis GP. Selenium-Dependent Antioxidant Enzymes: Actions and Properties of Selenoproteins. Antioxidants (Basel) 2018; 7:E66. [PMID: 29758013 PMCID: PMC5981252 DOI: 10.3390/antiox7050066] [Citation(s) in RCA: 217] [Impact Index Per Article: 36.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Revised: 05/07/2018] [Accepted: 05/09/2018] [Indexed: 12/23/2022] Open
Abstract
Unlike other essential trace elements that interact with proteins in the form of cofactors, selenium (Se) becomes co-translationally incorporated into the polypeptide chain as part of 21st naturally occurring amino acid, selenocysteine (Sec), encoded by the UGA codon. Any protein that includes Sec in its polypeptide chain is defined as selenoprotein. Members of the selenoproteins family exert various functions and their synthesis depends on specific cofactors and on dietary Se. The Se intake in productive animals such as chickens affect nutrient utilization, production performances, antioxidative status and responses of the immune system. Although several functions of selenoproteins are unknown, many disorders are related to alterations in selenoprotein expression or activity. Selenium insufficiency and polymorphisms or mutations in selenoproteins' genes and synthesis cofactors are involved in the pathophysiology of many diseases, including cardiovascular disorders, immune dysfunctions, cancer, muscle and bone disorders, endocrine functions and neurological disorders. Finally, heavy metal poisoning decreases mRNA levels of selenoproteins and increases mRNA levels of inflammatory factors, underlying the antagonistic effect of Se. This review is an update on Se dependent antioxidant enzymes, presenting the current state of the art and is focusing on results obtained mainly in chicken.
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Affiliation(s)
- Evangelos Zoidis
- Department of Nutritional Physiology and Feeding, Faculty of Animal Science and Aquaculture, Agricultural University of Athens, 75 Iera Odos, 11855 Athens, Greece.
| | - Isidoros Seremelis
- Chemistry Laboratory, Department of Food Science and Human Nutrition, Agricultural University of Athens, 75 Iera Odos, 11855 Athens, Greece.
| | - Nikolaos Kontopoulos
- Chemistry Laboratory, Department of Food Science and Human Nutrition, Agricultural University of Athens, 75 Iera Odos, 11855 Athens, Greece.
| | - Georgios P Danezis
- Chemistry Laboratory, Department of Food Science and Human Nutrition, Agricultural University of Athens, 75 Iera Odos, 11855 Athens, Greece.
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12
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Abstract
Five out of eight human glutathione peroxidases (GPxes) are selenoproteins and thus their expression depends on the selenium (Se) supply. Most Se-dependent GPxes are downregulated in tumor cells, while only GPx2 is considerably upregulated. Whether expression profiles of GPxes predict tumor development and patient survival is controversially discussed. Also, results from in vitro and in vivo studies modulating the expression of GPx isoforms provide evidence for both anti- and procarcinogenic mechanisms. GPxes are able to reduce hydroperoxides, which otherwise would damage DNA, possibly resulting in DNA mutations, modulate redox-sensitive signaling pathways affecting proliferation, differentiation, and cellular metabolism or initiate cell death. Considering these different processes, the role and functions of individual Se-dependent GPx isoforms will be discussed herein in the context of tumorigenesis.
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Affiliation(s)
- Anna P Kipp
- Institute of Nutrition, Friedrich Schiller University Jena, Jena, Germany.
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13
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Carlson BA, Gupta N, Pinkerton MH, Hatfield DL, Copeland PR. The utilization of selenocysteine-tRNA [Ser]Sec isoforms is regulated in part at the level of translation in vitro. ACTA ACUST UNITED AC 2017; 5:e1314240. [PMID: 28702279 DOI: 10.1080/21690731.2017.1314240] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Revised: 03/27/2017] [Accepted: 03/28/2017] [Indexed: 10/19/2022]
Abstract
The tRNA for the 21st proteinogenic amino acid, selenocysteine, exists in mammalian cells as 2 isoforms differing by a single 2'-O-methylribosyl moiety at position 34 (Um34). These isoforms contain either 5-methoxycarbonylmethyluridine (mcm5U) or 5-methoxycarbonylmethyl-2'-O-methyluridine (mcm5Um) at position 34. The accumulation of the mcm5Um isoform is tightly correlated with the expression of nonessential "stress response" selenoproteins such as glutathione peroxidase 1 (GPX1). The expression of essential selenoproteins, such as thioredoxin reductase 1 (TXNRD1), is not affected by changes in Sec-tRNA[Ser]Sec isoform accumulation. In this work we used purified mcm5U and mcm5Um Sec-tRNA[Ser]Sec isoforms to analyze possible differences in binding to the selenocysteine-specific elongation factor, EEFSEC, and the translation of GPX1 and TXNRD1in vitro. Our results indicate that no major distinction between mcm5U and mcm5Um isoforms is made by the translation machinery, but a small consistent increase in GPX1 translation is associated with the mcm5Um isoform. These results implicate fundamental differences in translation efficiency in playing a role in regulating selenoprotein expression as a function of isoform accumulation.
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Affiliation(s)
- Bradley A Carlson
- Molecular Biology of Selenium Section, Mouse Cancer Genetics Program, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Nirupama Gupta
- Department of Biochemistry and Molecular Biology, Rutgers - Robert Wood Johnson Medical School, Piscataway, NJ, USA
| | - Mark H Pinkerton
- Department of Biochemistry and Molecular Biology, Rutgers - Robert Wood Johnson Medical School, Piscataway, NJ, USA
| | - Dolph L Hatfield
- Molecular Biology of Selenium Section, Mouse Cancer Genetics Program, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Paul R Copeland
- Department of Biochemistry and Molecular Biology, Rutgers - Robert Wood Johnson Medical School, Piscataway, NJ, USA
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14
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Mohan A, Poulose R, Gupta T, Luthra K, Pandey RM, Madan K, Hadda V, Guleria R. Impact of chemotherapy on symptom profile, oxidant-antioxidant balance and nutritional status in non-small cell Lung Cancer. Lung India 2017; 34:336-340. [PMID: 28671164 PMCID: PMC5504890 DOI: 10.4103/0970-2113.209230] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND Lung cancer is associated with an oxidant-antioxidant imbalance that is implicated in tumor progression. However, the association of this imbalance on disease burden and treatment response is unclear. The effect of chemotherapy on oxidative stress, antioxidant status, and nutritional profile in patients with advanced nonsmall cell lung cancer (NSCLC) was prospectively evaluated. SUBJECTS AND METHODS Patients with confirmed cytological/histological diagnosis of NSCLC were recruited. Performance status was determined using the Eastern Cooperative Oncology Group grading and the Karnofsky Performance Scale. Skin fold anthropometry was done for nutritional assessment. All patients received chemotherapy with intravenous carboplatin and paclitaxel at three-weekly intervals. Response was assessed after four cycles by repeat imaging. Plasma levels of total antioxidant status (TAS), malondialdehyde (MDA), and glutathione peroxidase (GPx) levels were estimated using commercially available kits, and the change was correlated with clinical outcome, response to chemotherapy, performance status, and nutritional profile. RESULTS Thirty-five cases were studied (92% males), with a mean (SD) age of 56.2 (9.3) years. Following treatment, majority of patients demonstrated stable disease (n = 15 [42%]), followed by partial response (29%), progressive disease (22%), and complete remission (6%). Significant improvement occurred in respiratory symptoms. Body fat declined while subscapular skinfold thickness and 6-min walk distance increased. Spirometric values and performance status remained unchanged. GPx levels declined significantly while no notable change was observed in MDA and TAS levels. CONCLUSIONS Chemotherapy for NSCLC improves symptoms, nutritional status, and exercise capacity but worsens the antioxidant status.
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Affiliation(s)
- Anant Mohan
- Department of Pulmonary Medicine and Sleep Disorders, AIIMS, New Delhi, India
| | - Rosemary Poulose
- Department of Pulmonary Medicine and Sleep Disorders, AIIMS, New Delhi, India
| | - Tarang Gupta
- Department of Pulmonary Medicine and Sleep Disorders, AIIMS, New Delhi, India
| | | | | | - Karan Madan
- Department of Pulmonary Medicine and Sleep Disorders, AIIMS, New Delhi, India
| | - Vijay Hadda
- Department of Pulmonary Medicine and Sleep Disorders, AIIMS, New Delhi, India
| | - Randeep Guleria
- Department of Pulmonary Medicine and Sleep Disorders, AIIMS, New Delhi, India
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15
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Dong R, Wang D, Wang X, Zhang K, Chen P, Yang CS, Zhang J. Epigallocatechin-3-gallate enhances key enzymatic activities of hepatic thioredoxin and glutathione systems in selenium-optimal mice but activates hepatic Nrf2 responses in selenium-deficient mice. Redox Biol 2016; 10:221-232. [PMID: 27810737 PMCID: PMC5094413 DOI: 10.1016/j.redox.2016.10.009] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2016] [Revised: 10/16/2016] [Accepted: 10/21/2016] [Indexed: 12/20/2022] Open
Abstract
Selenium participates in the antioxidant defense mainly through a class of selenoproteins, including thioredoxin reductase. Epigallocatechin-3-gallate (EGCG) is the most abundant and biologically active catechin in green tea. Depending upon the dose and biological systems, EGCG may function either as an antioxidant or as an inducer of antioxidant defense via its pro-oxidant action or other unidentified mechanisms. By manipulating the selenium status, the present study investigated the interactions of EGCG with antioxidant defense systems including the thioredoxin system comprising of thioredoxin and thioredoxin reductase, the glutathione system comprising of glutathione and glutathione reductase coupled with glutaredoxin, and the Nrf2 system. In selenium-optimal mice, EGCG increased hepatic activities of thioredoxin reductase, glutathione reductase and glutaredoxin. These effects of EGCG appeared to be not due to overt pro-oxidant action because melatonin, a powerful antioxidant, did not influence the increase. However, in selenium-deficient mice, with low basal levels of thioredoxin reductase 1, the same dose of EGCG did not elevate the above-mentioned enzymes; intriguingly EGCG in turn activated hepatic Nrf2 response, leading to increased heme oxygenase 1 and NAD(P)H:quinone oxidoreductase 1 protein levels and thioredoxin activity. Overall, the present work reveals that EGCG is a robust inducer of the Nrf2 system only in selenium-deficient conditions. Under normal physiological conditions, in selenium-optimal mice, thioredoxin and glutathione systems serve as the first line defense systems against the stress induced by high doses of EGCG, sparing the activation of the Nrf2 system. EGCG increases hepatic activities of TrxR, GR and Grx in selenium-optimal mice. EGCG fails to manipulate the above-mentioned enzymes in selenium-deficient mice. EGCG in turn activates hepatic Nrf2 response in selenium-deficient mice. Selenium deficiency does not increase EGCG toxicity due to potent Nrf2 response.
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Affiliation(s)
- Ruixia Dong
- State Key Laboratory of Tea Plant Biology and Utilization, School of Tea & Food Science, Anhui Agricultural University, Hefei, Anhui, China; Department of Forestry and Technology, Lishui Vocational and Technical College, Lishui, Zhejiang, China
| | - Dongxu Wang
- State Key Laboratory of Tea Plant Biology and Utilization, School of Tea & Food Science, Anhui Agricultural University, Hefei, Anhui, China; International Joint Research Laboratory of Tea Chemistry and Health Effects, Anhui Agricultural University, Hefei, Anhui, China
| | - Xiaoxiao Wang
- State Key Laboratory of Tea Plant Biology and Utilization, School of Tea & Food Science, Anhui Agricultural University, Hefei, Anhui, China
| | - Ke Zhang
- State Key Laboratory of Tea Plant Biology and Utilization, School of Tea & Food Science, Anhui Agricultural University, Hefei, Anhui, China
| | - Pingping Chen
- State Key Laboratory of Tea Plant Biology and Utilization, School of Tea & Food Science, Anhui Agricultural University, Hefei, Anhui, China
| | - Chung S Yang
- Department of Chemical Biology, Ernest Mario School of Pharmacy, Rutgers, The State University of New Jersey, Piscataway, NJ, USA; International Joint Research Laboratory of Tea Chemistry and Health Effects, Anhui Agricultural University, Hefei, Anhui, China
| | - Jinsong Zhang
- State Key Laboratory of Tea Plant Biology and Utilization, School of Tea & Food Science, Anhui Agricultural University, Hefei, Anhui, China; International Joint Research Laboratory of Tea Chemistry and Health Effects, Anhui Agricultural University, Hefei, Anhui, China.
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16
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Borlak J, Singh P, Gazzana G. Proteome mapping of epidermal growth factor induced hepatocellular carcinomas identifies novel cell metabolism targets and mitogen activated protein kinase signalling events. BMC Genomics 2015; 16:124. [PMID: 25872475 PMCID: PMC4357185 DOI: 10.1186/s12864-015-1312-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Accepted: 02/03/2015] [Indexed: 02/06/2023] Open
Abstract
Background Hepatocellular carcinoma (HCC) is on the rise and the sixth most common cancer worldwide. To combat HCC effectively research is directed towards its early detection and the development of targeted therapies. Given the fact that epidermal growth factor (EGF) is an important mitogen for hepatocytes we searched for disease regulated proteins to improve an understanding of the molecular pathogenesis of EGF induced HCC. Disease regulated proteins were studied by 2DE MALDI-TOF/TOF and a transcriptomic approach, by immunohistochemistry and advanced bioinformatics. Results Mapping of EGF induced liver cancer in a transgenic mouse model identified n = 96 (p < 0.05) significantly regulated proteins of which n = 54 were tumour-specific. To unravel molecular circuits linked to aberrant EGFR signalling diverse computational approaches were employed and this defined n = 7 key nodes using n = 82 disease regulated proteins for network construction. STRING analysis revealed protein-protein interactions of > 70% disease regulated proteins with individual proteins being validated by immunohistochemistry. The disease regulated network proteins were mapped to distinct pathways and bioinformatics provided novel insight into molecular circuits associated with significant changes in either glycolysis and gluconeogenesis, argine and proline metabolism, protein processing in endoplasmic reticulum, Hif- and MAPK signalling, lipoprotein metabolism, platelet activation and hemostatic control as a result of aberrant EGF signalling. The biological significance of the findings was corroborated with gene expression data derived from tumour tissues to evntually define a rationale by which tumours embark on intriguing changes in metabolism that is of utility for an understanding of tumour growth. Moreover, among the EGF tumour specific proteins n = 11 were likewise uniquely expressed in human HCC and for n = 49 proteins regulation in human HCC was confirmed using the publically available Human Protein Atlas depository, therefore demonstrating clinical significance. Conclusion Novel insight into the molecular pathogenesis of EGF induced liver cancer was obtained and among the 37 newly identified proteins several are likely candidates for the development of molecularly targeted therapies and include the nucleoside diphosphate kinase A, bifunctional ATP-dependent dihydroyacetone kinase and phosphatidylethanolamine-binding protein1, the latter being an inhibitor of the Raf-1 kinase. Electronic supplementary material The online version of this article (doi:10.1186/s12864-015-1312-z) contains supplementary material, which is available to authorized users.
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17
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Kang SW, Lee S, Lee EK. ROS and energy metabolism in cancer cells: alliance for fast growth. Arch Pharm Res 2015; 38:338-45. [PMID: 25599615 DOI: 10.1007/s12272-015-0550-6] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2014] [Accepted: 01/05/2015] [Indexed: 10/24/2022]
Abstract
In normal cells, the cellular reactive oxygen species (ROS) level is proportional to the activity of mitochondrial electron transport and tightly controlled by endogenous antioxidant system. However, energy metabolism and ROS homeostasis in cancer cells are much different from those in normal cells. For example, a majority of cellular glucose is metabolized through aerobic glycolysis ("Warburg effect") and the pentose phosphate pathway. Cancer cells harbor functional mitochondria, but many mutations in nuclear DNA-encoded mitochondrial genes and mitochondrial genome result in the mitochondrial metabolic reprogramming. The other characteristic of cancer cells is to maintain much higher ROS level than normal cells. Ironically, cancer cells overexpress the ROS-producing NADPH oxidase and the ROS-eliminating antioxidant enzymes, both of which enzyme systems share NADPH as a reducing power source. In this article, we review the complex connection between ROS and energy metabolisms in cancer cells.
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Affiliation(s)
- Sang Won Kang
- Department of Life Sciences, Research Center for Cell Homeostasis, Ewha Womans University, Seoul, 120-750, Republic of Korea,
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18
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Barroso M, Florindo C, Kalwa H, Silva Z, Turanov AA, Carlson BA, de Almeida IT, Blom HJ, Gladyshev VN, Hatfield DL, Michel T, Castro R, Loscalzo J, Handy DE. Inhibition of cellular methyltransferases promotes endothelial cell activation by suppressing glutathione peroxidase 1 protein expression. J Biol Chem 2014; 289:15350-62. [PMID: 24719327 PMCID: PMC4140892 DOI: 10.1074/jbc.m114.549782] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
S-adenosylhomocysteine (SAH) is a negative regulator of most methyltransferases and the precursor for the cardiovascular risk factor homocysteine. We have previously identified a link between the homocysteine-induced suppression of the selenoprotein glutathione peroxidase 1 (GPx-1) and endothelial dysfunction. Here we demonstrate a specific mechanism by which hypomethylation, promoted by the accumulation of the homocysteine precursor SAH, suppresses GPx-1 expression and leads to inflammatory activation of endothelial cells. The expression of GPx-1 and a subset of other selenoproteins is dependent on the methylation of the tRNA(Sec) to the Um34 form. The formation of methylated tRNA(Sec) facilitates translational incorporation of selenocysteine at a UGA codon. Our findings demonstrate that SAH accumulation in endothelial cells suppresses the expression of GPx-1 to promote oxidative stress. Hypomethylation stress, caused by SAH accumulation, inhibits the formation of the methylated isoform of the tRNA(Sec) and reduces GPx-1 expression. In contrast, under these conditions, the expression and activity of thioredoxin reductase 1, another selenoprotein, is increased. Furthermore, SAH-induced oxidative stress creates a proinflammatory activation of endothelial cells characterized by up-regulation of adhesion molecules and an augmented capacity to bind leukocytes. Taken together, these data suggest that SAH accumulation in endothelial cells can induce tRNA(Sec) hypomethylation, which alters the expression of selenoproteins such as GPx-1 to contribute to a proatherogenic endothelial phenotype.
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Affiliation(s)
- Madalena Barroso
- From the Cardiovascular and ,the Research Institute for Medicines and Pharmaceutical Sciences (iMed.UL) and
| | - Cristina Florindo
- the Research Institute for Medicines and Pharmaceutical Sciences (iMed.UL) and
| | | | - Zélia Silva
- the Chronic Diseases Research Center, Departamento de Imunologia, Faculdade de Ciências Médicas, Universidade Nova de Lisboa, 1099-085 Lisbon, Portugal
| | - Anton A. Turanov
- Genetics Divisions, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts 02115
| | - Bradley A. Carlson
- the Molecular Biology of Selenium Section, Mouse Cancer Genetics Program, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, and
| | - Isabel Tavares de Almeida
- the Research Institute for Medicines and Pharmaceutical Sciences (iMed.UL) and ,Department of Biochemistry and Human Biology, Faculty of Pharmacy, University of Lisbon, 1649-004 Lisbon, Portugal
| | - Henk J. Blom
- the Department of General Pediatrics, Center for Pediatrics and Adolescent Medicine, University Hospital, 79106 Freiburg, Germany
| | - Vadim N. Gladyshev
- Genetics Divisions, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts 02115
| | - Dolph L. Hatfield
- the Molecular Biology of Selenium Section, Mouse Cancer Genetics Program, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, and
| | | | - Rita Castro
- the Research Institute for Medicines and Pharmaceutical Sciences (iMed.UL) and ,Department of Biochemistry and Human Biology, Faculty of Pharmacy, University of Lisbon, 1649-004 Lisbon, Portugal
| | | | - Diane E. Handy
- From the Cardiovascular and , To whom correspondence should be addressed: Cardiovascular Div., Dept. of Medicine, Brigham and Women's Hospital and Harvard Medical School, 77 Ave. Louis Pasteur, Boston, MA, 02115. Tel.: 617-525-4845; Fax: 617-525-4830; E-mail:
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19
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Hsieh YS, Hsu CY. Oxidative stress and anti-oxidant enzyme activities in the trophocytes and fat cells of queen honeybees (Apis mellifera). Rejuvenation Res 2014; 16:295-303. [PMID: 23738955 DOI: 10.1089/rej.2013.1420] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Trophocytes and fat cells of queen honeybees have been used for delayed cellular senescence studies, but their oxidative stress and anti-oxidant enzyme activities with advancing age are unknown. In this study, we assayed reactive oxygen species (ROS) and anti-oxidant enzymes in the trophocytes and fat cells of young and old queens. Young queens had lower ROS levels, lower superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) activities, and higher thioredoxin reductase (TR) activity compared to old queens. These results show that oxidative stress and anti-oxidant enzyme activities in trophocytes and fat cells increase with advancing age in queens and suggest that an increase in oxidative stress and a consequent increase in stress defense mechanisms are associated with the longevity of queen honeybees.
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Affiliation(s)
- Yu-Shan Hsieh
- Department of Biomedical Sciences, College of Medicine, Chang Gung University, Tao-Yuan, Taiwan
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20
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Steinbrenner H, Speckmann B, Sies H. Toward understanding success and failures in the use of selenium for cancer prevention. Antioxid Redox Signal 2013; 19:181-91. [PMID: 23421468 PMCID: PMC3689159 DOI: 10.1089/ars.2013.5246] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
SIGNIFICANCE Adequate and supranutritional selenium (Se) intake, maintaining full expression of selenoproteins, has been assumed to be beneficial for human health with respect to prevention of cancer. Strikingly, the effectiveness of dietary Se supplementation depends on many factors: baseline Se status, age, gender, and genetic background of an individual; type of cancer; and time point of intervention in addition to metabolic conversion and dose of applied Se compounds. RECENT ADVANCES Se intake levels for optimization of plasma selenoproteins in humans have been delineated. Regulation, function, and genetic variants of several selenoproteins have been characterized in the intestine, where Se-mediated prevention of colorectal cancer appears to be particularly promising. CRITICAL ISSUES Numerous cell culture and animal studies indicate anticarcinogenic capacity of various Se compounds but, at present, the outcome of human studies is inconsistent and, in large part, disappointing. Moreover, supranutritional Se intake may even trigger adverse health effects, possibly increasing the risk for Type 2 diabetes in Se-replete populations. FUTURE DIRECTIONS To improve protocols for the use of Se in cancer prevention, knowledge on cellular and systemic actions of Se compounds needs to be broadened and linked to individual-related determinants such as the occurrence of variants in selenoprotein genes and the Se status. Based on better mechanistic insight, populations and individuals that may benefit most from dietary Se supplementation need to be defined and studied in suitably planned intervention trials.
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Affiliation(s)
- Holger Steinbrenner
- Institute for Biochemistry and Molecular Biology I, Heinrich-Heine-University, Düsseldorf, Germany
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21
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Tobe R, Naranjo-Suarez S, Everley RA, Carlson BA, Turanov AA, Tsuji PA, Yoo MH, Gygi SP, Gladyshev VN, Hatfield DL. High error rates in selenocysteine insertion in mammalian cells treated with the antibiotic doxycycline, chloramphenicol, or geneticin. J Biol Chem 2013; 288:14709-15. [PMID: 23589299 DOI: 10.1074/jbc.m112.446666] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Antibiotics target bacteria by interfering with essential processes such as translation, but their effects on translation in mammalian cells are less well characterized. We found that doxycycline, chloramphenicol, and Geneticin (G418) interfered with insertion of selenocysteine (Sec), which is encoded by the stop codon, UGA, into selenoproteins in murine EMT6 cells. Treatment of EMT6 cells with these antibiotics reduced enzymatic activities and Sec insertion into thioredoxin reductase 1 (TR1) and glutathione peroxidase 1 (GPx1). However, these proteins were differentially affected due to varying errors in Sec insertion at UGA. In the presence of doxycycline, chloramphenicol, or G418, the Sec-containing form of TR1 decreased, whereas the arginine-containing and truncated forms of this protein increased. We also detected antibiotic-specific misinsertion of cysteine and tryptophan. Furthermore, misinsertion of arginine in place of Sec was commonly observed in GPx1 and glutathione peroxidase 4. TR1 was the most affected and GPx1 was the least affected by these translation errors. These observations were consistent with the differential use of two Sec tRNA isoforms and their distinct roles in supporting accuracy of Sec insertion into selenoproteins. The data reveal widespread errors in inserting Sec into proteins and in dysregulation of selenoprotein expression and function upon antibiotic treatment.
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Affiliation(s)
- Ryuta Tobe
- Molecular Biology of Selenium Section, Laboratory of Cancer Prevention, Center for Cancer Research, NCI, National Institutes of Health, Bethesda, Maryland 20892, USA
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22
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Abstract
The discovery of multiple selenoproteins has raised tantalizing questions about their role in maintaining normal cellular function. Unfortunately, many of these remain inadequately investigated. While they have a role in maintaining redox balance, other functions are becoming increasingly recognized. As the roles of these selenoproteins are further characterized, a better understanding of the true physiological significance of this trace element will arise. This knowledge will be essential in defining optimum intakes to achieve cellular homeostasis in order to optimize health, including a reduction in cancer, for diverse populations. Human variation in the response to selenium likely reflects significant interactions between the type and amounts of selenium consumed with the genome and a host of environmental factors including the totality of the diet, as discussed in this review.
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Affiliation(s)
- Cindy D. Davis
- Nutritional Science Research Group, National Cancer Institute, Rockville, Maryland 20892;,
- Current address: Office of Dietary Supplements, National Institutes of Health, Rockville, Maryland 20892
| | - Petra A. Tsuji
- Department of Biological Sciences, Towson University, Towson, Maryland 21252
| | - John A. Milner
- Nutritional Science Research Group, National Cancer Institute, Rockville, Maryland 20892;,
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23
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Næss S, Shiryaev A, Hov JR, Franke A, Karlsen TH. Genetics in primary sclerosing cholangitis. Clin Res Hepatol Gastroenterol 2012; 36:325-33. [PMID: 22554879 DOI: 10.1016/j.clinre.2012.02.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2012] [Accepted: 02/24/2012] [Indexed: 02/04/2023]
Abstract
Primary sclerosing cholangitis (PSC) is a chronic cholestatic disorder with a progressive course. PSC is strongly associated with inflammatory bowel disease and is often complicated by cholangiocarcinoma development. Etiology and pathogenesis remain obscure, but the diverse clinical manifestation of the disease might, to some extent, indicate different genetic susceptibility in subgroups of patients. In recent years, genome-wide association studies performed in PSC have identified a number of genetic susceptibility loci. In this mini-review, we suggest that the genetic associations established can be grouped according to four pathogenic aspects relating to inflammation, cholangiocyte function, fibrosis and carcinogenesis. Subclassification of PSC patients according to their genetic predisposition could be a valuable tool in future functional and clinical studies.
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Affiliation(s)
- Sigrid Næss
- Norwegian PSC Research Center, Division of Cancer, Surgery and Transplantation, Oslo University Hospital Rikshospitalet, 0027 Oslo, Norway
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24
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Barrera LN, Cassidy A, Wang W, Wei T, Belshaw NJ, Johnson IT, Brigelius-Flohé R, Bao Y. TrxR1 and GPx2 are potently induced by isothiocyanates and selenium, and mutually cooperate to protect Caco-2 cells against free radical-mediated cell death. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2012; 1823:1914-24. [PMID: 22820176 DOI: 10.1016/j.bbamcr.2012.07.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2012] [Revised: 07/03/2012] [Accepted: 07/12/2012] [Indexed: 02/07/2023]
Abstract
Currently, there is significant interest in the field of diet-gene interactions and the mechanisms by which food compounds regulate gene expression to modify cancer susceptibility. From a nutrition perspective, two key components potentially exert cancer chemopreventive effects: isothiocyanates (ITCs), present in cruciferous vegetables, and selenium (Se) which, as selenocysteine, is an integral part of selenoproteins. However, the role of these compounds in the expression of key selenoenzymes once the cancer process has been initiated still needs elucidation. Therefore, this investigation examined the effect of two forms of selenium, selenium-methylselenocysteine and sodium selenite, both individually and in combination with two ITCs, sulforaphane or iberin, on the expression of the two selenoenzymes, thioredoxin reductase 1 (TrxR1) and gastrointestinal glutathione peroxidase (GPx2), which are targets of ITCs, in Caco-2 cells. Co-treatment with both ITCs and Se induced expression of TrxR1 and GPx2 more than either compound alone. Moreover, pre-treatment of cells with ITC+Se enhanced cytoprotection against H(2)O(2)-induced cell death through a ROS-dependent mechanism. Furthermore, a single and double knockdown of TrxR1 and/or GPx2 suggested that both selenoproteins were responsible for protecting against H(2)O(2)-induced cell death. Together, these data shed new light on the mechanism of interactions between ITC and Se in which translational expression of the enhanced transcripts by the former is dependent on an adequate Se supply, resulting in a cooperative antioxidant protective effect against cell death.
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Affiliation(s)
- Lawrence N Barrera
- Department of Nutrition, Norwich Medical School, University of East Anglia, Norwich, UK
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25
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Carlson BA, Yoo MH, Tobe R, Mueller C, Naranjo-Suarez S, Hoffmann VJ, Gladyshev VN, Hatfield DL. Thioredoxin reductase 1 protects against chemically induced hepatocarcinogenesis via control of cellular redox homeostasis. Carcinogenesis 2012; 33:1806-13. [PMID: 22791808 DOI: 10.1093/carcin/bgs230] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Thioredoxin reductase 1 (TR1) controls the redox state of protein thiols in mammalian cells and has been shown to have roles in both preventing and promoting cancer. To define the role of this selenoenzyme in hepatocellular carcinoma development, we examined tumor incidence in the liver of mice with tissue-specific knockout of mouse TR1 subjected to the liver carcinogen, diethylnitrosamine (DEN). TR1-deficient livers manifested ~90% tumor incidence compared with ~16% in control livers. The TR1-dependent effect was observed independent of sex, and, in control mice, tumorigenesis did not affect the expression of TR1. On the other hand, we observed upregulation of another selenoenzyme, glutathione peroxidase 2 (GPx2), and components of the glutathione (GSH) system, including those that generate reduced GSH. Overall, this study shows that TR1 protects against chemically induced hepatocarcinogenesis via the control of the cellular redox state, whereas its role in promoting this type of cancer is minimal.
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Affiliation(s)
- Bradley A Carlson
- Molecular Biology of Selenium Section, Laboratory of Cancer Prevention, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
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Lubos E, Loscalzo J, Handy DE. Glutathione peroxidase-1 in health and disease: from molecular mechanisms to therapeutic opportunities. Antioxid Redox Signal 2011; 15:1957-97. [PMID: 21087145 PMCID: PMC3159114 DOI: 10.1089/ars.2010.3586] [Citation(s) in RCA: 773] [Impact Index Per Article: 59.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Reactive oxygen species, such as superoxide and hydrogen peroxide, are generated in all cells by mitochondrial and enzymatic sources. Left unchecked, these reactive species can cause oxidative damage to DNA, proteins, and membrane lipids. Glutathione peroxidase-1 (GPx-1) is an intracellular antioxidant enzyme that enzymatically reduces hydrogen peroxide to water to limit its harmful effects. Certain reactive oxygen species, such as hydrogen peroxide, are also essential for growth factor-mediated signal transduction, mitochondrial function, and maintenance of normal thiol redox-balance. Thus, by limiting hydrogen peroxide accumulation, GPx-1 also modulates these processes. This review explores the molecular mechanisms involved in regulating the expression and function of GPx-1, with an emphasis on the role of GPx-1 in modulating cellular oxidant stress and redox-mediated responses. As a selenocysteine-containing enzyme, GPx-1 expression is subject to unique forms of regulation involving the trace mineral selenium and selenocysteine incorporation during translation. In addition, GPx-1 has been implicated in the development and prevention of many common and complex diseases, including cancer and cardiovascular disease. This review discusses the role of GPx-1 in these diseases and speculates on potential future therapies to harness the beneficial effects of this ubiquitous antioxidant enzyme.
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Affiliation(s)
- Edith Lubos
- Department of Medicine II, University Medical Center, Johannes Gutenberg-University, Mainz, Germany
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Ufer C, Wang CC. The Roles of Glutathione Peroxidases during Embryo Development. Front Mol Neurosci 2011; 4:12. [PMID: 21847368 PMCID: PMC3148772 DOI: 10.3389/fnmol.2011.00012] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2011] [Accepted: 07/13/2011] [Indexed: 01/31/2023] Open
Abstract
Embryo development relies on the complex interplay of the basic cellular processes including proliferation, differentiation, and apoptotic cell death. Precise regulation of these events is the basis for the establishment of embryonic structures and the organ development. Beginning with fertilization of the oocyte until delivery the developing embryo encounters changing environmental conditions such as varying levels of oxygen, which can give rise to reactive oxygen species (ROS). These challenges are met by the embryo with metabolic adaptations and by an array of anti-oxidative mechanisms. ROS can be deleterious by modifying biological molecules including lipids, proteins, and nucleic acids and may induce abnormal development or even embryonic lethality. On the other hand ROS are vital players of various signaling cascades that affect the balance between cell growth, differentiation, and death. An imbalance or dysregulation of these biological processes may generate cells with abnormal growth and is therefore potentially teratogenic and tumorigenic. Thus, a precise balance between processes generating ROS and those decomposing ROS is critical for normal embryo development. One tier of the cellular protective system against ROS constitutes the family of selenium-dependent glutathione peroxidases (GPx). These enzymes reduce hydroperoxides to the corresponding alcohols at the expense of reduced glutathione. Of special interest within this protein family is the moonlighting enzyme glutathione peroxidase 4 (Gpx4). This enzyme is a scavenger of lipophilic hydroperoxides on one hand, but on the other hand can be transformed into an enzymatically inactive cellular structural component. GPx4 deficiency - in contrast to all other GPx family members - leads to abnormal embryo development and finally produces a lethal phenotype in mice. This review is aimed at summarizing the current knowledge on GPx isoforms during embryo development and tumor development with an emphasis on GPx4.
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Affiliation(s)
- Christoph Ufer
- Institute of Biochemistry, Charité - University Medicine Berlin Berlin, Germany
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Labunskyy VM, Lee BC, Handy DE, Loscalzo J, Hatfield DL, Gladyshev VN. Both maximal expression of selenoproteins and selenoprotein deficiency can promote development of type 2 diabetes-like phenotype in mice. Antioxid Redox Signal 2011; 14:2327-36. [PMID: 21194350 PMCID: PMC3096499 DOI: 10.1089/ars.2010.3526] [Citation(s) in RCA: 144] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Selenium (Se) is an essential trace element in mammals that has been shown to exert its function through selenoproteins. Whereas optimal levels of Se in the diet have important health benefits, a recent clinical trial has suggested that supplemental intake of Se above the adequate level potentially may raise the risk of type 2 diabetes mellitus. However, the molecular mechanisms for the effect of dietary Se on the development of this disease are not understood. In the present study, we examined the contribution of selenoproteins to increased risk of developing diabetes using animal models. C57BL/6J mice (n=6-7 per group) were fed either Se-deficient Torula yeast-based diet or diets supplemented with 0.1 and 0.4 parts per million Se. Our data show that mice maintained on an Se-supplemented diet develop hyperinsulinemia and have decreased insulin sensitivity. These effects are accompanied by elevated expression of a selective group of selenoproteins. We also observed that reduced synthesis of these selenoproteins caused by overexpression of an i(6)A(-) mutant selenocysteine tRNA promotes glucose intolerance and leads to a diabetes-like phenotype. These findings indicate that both high expression of selenoproteins and selenoprotein deficiency may dysregulate glucose homeostasis and suggest a role for selenoproteins in development of diabetes.
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Affiliation(s)
- Vyacheslav M Labunskyy
- Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, 77 Ave. Louis Pasteur, Boston, MA 02115, USA
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Kasaikina MV, Lobanov AV, Malinouski MY, Lee BC, Seravalli J, Fomenko DE, Turanov AA, Finney L, Vogt S, Park TJ, Miller RA, Hatfield DL, Gladyshev VN. Reduced utilization of selenium by naked mole rats due to a specific defect in GPx1 expression. J Biol Chem 2011; 286:17005-14. [PMID: 21372135 DOI: 10.1074/jbc.m110.216267] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Naked mole rat (MR) Heterocephalus glaber is a rodent model of delayed aging because of its unusually long life span (>28 years). It is also not known to develop cancer. In the current work, tissue imaging by x-ray fluorescence microscopy and direct analyses of trace elements revealed low levels of selenium in the MR liver and kidney, whereas MR and mouse brains had similar selenium levels. This effect was not explained by uniform selenium deficiency because methionine sulfoxide reductase activities were similar in mice and MR. However, glutathione peroxidase activity was an order of magnitude lower in MR liver and kidney than in mouse tissues. In addition, metabolic labeling of MR cells with (75)Se revealed a loss of the abundant glutathione peroxidase 1 (GPx1) band, whereas other selenoproteins were preserved. To characterize the MR selenoproteome, we sequenced its liver transcriptome. Gene reconstruction revealed standard selenoprotein sequences except for GPx1, which had an early stop codon, and SelP, which had low selenocysteine content. When expressed in HEK 293 cells, MR GPx1 was present in low levels, and its expression could be rescued neither by removing the early stop codon nor by replacing its SECIS element. In addition, GPx1 mRNA was present in lower levels in MR liver than in mouse liver. To determine if GPx1 deficiency could account for the reduced selenium content, we analyzed GPx1 knock-out mice and found reduced selenium levels in their livers and kidneys. Thus, MR is characterized by the reduced utilization of selenium due to a specific defect in GPx1 expression.
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Affiliation(s)
- Marina V Kasaikina
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA
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Glauert HP, Calfee-Mason K, Stemm DN, Tharappel JC, Spear BT. Dietary antioxidants in the prevention of hepatocarcinogenesis: a review. Mol Nutr Food Res 2010; 54:875-96. [PMID: 20512789 DOI: 10.1002/mnfr.200900482] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
In this review, the role of dietary antioxidants in the prevention of hepatocarcinogenesis is examined. Both human and animal models are discussed. Vitamin C, vitamin E, and selenium are antioxidants that are essential in the human diet. A number of non-essential chemicals also contain antioxidant activity and are consumed in the human diet, mainly as plants or as supplements, including beta-carotene, ellagic acid, curcumin, lycopene, coenzyme Q(10), epigallocatechin gallate, N-acetyl cysteine, and resveratrol. Although some human and animal studies show protection against carcinogenesis with the consumption of higher amounts of antioxidants, many studies show no effect or an enhancement of carcinogenesis. Because of the conflicting results from these studies, it is difficult to make dietary recommendations as to whether consuming higher amounts of specific antioxidants will decrease the risk of developing hepatocellular carcinoma.
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Affiliation(s)
- Howard P Glauert
- Graduate Center for Nutritional Sciences, University of Kentucky, Lexington, KY 40506-0054, USA.
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Selenium: a double-edged sword for defense and offence in cancer. Arch Toxicol 2010; 84:919-38. [PMID: 20871980 DOI: 10.1007/s00204-010-0595-8] [Citation(s) in RCA: 239] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2010] [Accepted: 09/09/2010] [Indexed: 10/19/2022]
Abstract
Selenium (Se) is an essential dietary component for animals including humans and is regarded as a protective agent against cancer. Although the mode of anticancer action of Se is not fully understood yet, several mechanisms, such as antioxidant protection by selenoenzymes, specific inhibition of tumor cell growth by Se metabolites, modulation of cell cycle and apoptosis, and effect on DNA repair have all been proposed. Despite the unsupported results of the last SELECT trial, the cancer-preventing activity of Se was demonstrated in majority of the epidemiological studies. Moreover, recent studies suggest that Se has a potential to be used not only in cancer prevention but also in cancer treatment where in combination with other anticancer drugs or radiation, it can increase efficacy of cancer therapy. In combating cancer cells, Se acts as pro-oxidant rather than antioxidant, inducing apoptosis through the generation of oxidative stress. Thus, the inorganic Se compound, sodium selenite (SeL), due to its prooxidant character, represents a promising alternative for cancer therapy. However, this Se compound is highly toxic compared to organic Se forms. Thus, the unregulated intake of dietary or pharmacological Se supplements mainly in the form of SeL has a potential to expose the body tissues to the toxic levels of Se with subsequent negative consequences on DNA integrity. Hence, due to a broad interest to exploit the positive effects of Se on human health and cancer therapy, studies investigating the negative effects such as toxicity and DNA damage induction resulting from high Se intake are also highly required. Here, we review a role of Se in cancer prevention and cancer therapy, as well as mechanisms underlying Se-induced toxicity and DNA injury. Since Saccharomyces cerevisiae has proven a powerful tool for addressing some important questions regarding Se biology, a part of this review is devoted to this model system.
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Chemopreventive Effect of Different Ratios of Fish Oil and Corn Oil in Experimental Colon Carcinogenesis. Lipids 2010; 45:785-98. [DOI: 10.1007/s11745-010-3459-3] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2010] [Accepted: 07/29/2010] [Indexed: 01/11/2023]
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Selenius M, Rundlöf AK, Olm E, Fernandes AP, Björnstedt M. Selenium and the selenoprotein thioredoxin reductase in the prevention, treatment and diagnostics of cancer. Antioxid Redox Signal 2010; 12:867-80. [PMID: 19769465 DOI: 10.1089/ars.2009.2884] [Citation(s) in RCA: 133] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Selenium is an essential element that is specifically incorporated as selenocystein into selenoproteins. It is a potent modulator of eukaryotic cell growth with strictly concentration-dependant effects. Lower concentrations are necessary for cell survival and growth, whereas higher concentrations inhibit growth and induce cell death. It is well established that selenium has cancer preventive effects, and several studies also have shown that it has strong anticancer effects with a selective cytotoxicity on malignant drug-resistant cells while only exerting marginal effects on normal and benign cells. This cancer-specific cytotoxicity is likely explained by high affinity selenium uptake dependent on proteins connected to multidrug resistance. One of the most studied selenoproteins in cancer is thioredoxin reductase (TrxR) that has important functions in neoplastic growth and is an important component of the resistant phenotype. Several reports have shown that TrxR is induced in tumor cells and pre-neoplastic cells, and several commonly used drugs interact with the protein. In this review, we summarize the current knowledge of selenium as a potent preventive and tumor selective anticancer drug, and we also discuss the potential of using the expression and modulation of the selenoprotein TrxR in the diagnostics and treatment of cancer.
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Affiliation(s)
- Markus Selenius
- Division of Pathology, Department of Laboratory Medicine, Karolinska Institutet, Karolinska University Hospital Huddinge, Stockholm, Sweden
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Takata Y, Morris JS, King IB, Kristal AR, Lin DW, Peters U. Correlation between selenium concentrations and glutathione peroxidase activity in serum and human prostate tissue. Prostate 2009; 69:1635-42. [PMID: 19623542 PMCID: PMC3166332 DOI: 10.1002/pros.21012] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND Low serum selenium concentration has been associated with increased risk of prostate cancer. A possible mechanism is through the antioxidant activity of selenoenzymes. However, the effect of selenium intake on selenoenzymes at target tissues is not well established. Hence, we investigated the correlation between serum and prostate tissue selenium concentrations and prostate tissue activity of glutathione peroxidase (GPX), a major selenoenzyme with antioxidant properties. METHODS In an ongoing study investigating gene expression in prostate tissue, we measured serum selenium concentration in 98 men using atomic absorption spectrometry. Of these men, we selected 12 men with the highest and 12 men with the lowest serum selenium concentrations and measured selenium concentration and GPX activity in fresh frozen prostate tissue using the cyclic neutron activation analysis and a direct spectrophotometric procedure, respectively. RESULTS The mean serum selenium concentrations among low and high selenium groups were 123.7 +/- 5.9 and 196.7 +/- 16.6 microg/L (P < 0.0001), respectively. The corresponding mean prostate tissue selenium concentrations were 1.39 +/- 0.28 and 1.65 +/- 0.42 microg/g (P = 0.08), resulting in a positive correlation between serum and prostate tissue selenium concentrations (r = 0.56, P = 0.02). The mean prostate tissue GPX activity was non-significantly greater in the low serum selenium group (32.2 +/- 8.4 U/g protein) than in the high serum selenium group (29.6 +/- 5.9 U/g protein) (P = 0.39) and it was not correlated with serum or prostate tissue selenium concentrations (r = -0.22, P = -0.37 for serum and r = -0.33, P = 0.18 for prostate tissue). CONCLUSION Serum and prostate tissue selenium concentrations were moderately correlated. In this population with relatively high selenium concentration, neither prostate tissue nor serum selenium concentrations were associated with prostate tissue GPX activity.
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Affiliation(s)
- Yumie Takata
- Cancer Prevention Program, Fred Hutchinson Cancer Research Center, Seattle, WA
| | | | - Irena B. King
- Cancer Prevention Program, Fred Hutchinson Cancer Research Center, Seattle, WA
| | - Alan R. Kristal
- Cancer Prevention Program, Fred Hutchinson Cancer Research Center, Seattle, WA
| | - Daniel W. Lin
- University of Washington, Department of Urology, Seattle WA
| | - Ulrike Peters
- Cancer Prevention Program, Fred Hutchinson Cancer Research Center, Seattle, WA
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Reeves MA, Hoffmann PR. The human selenoproteome: recent insights into functions and regulation. Cell Mol Life Sci 2009; 66:2457-78. [PMID: 19399585 PMCID: PMC2866081 DOI: 10.1007/s00018-009-0032-4] [Citation(s) in RCA: 354] [Impact Index Per Article: 23.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2009] [Revised: 04/01/2009] [Accepted: 04/03/2009] [Indexed: 12/16/2022]
Abstract
Selenium (Se) is a nutritional trace mineral essential for various aspects of human health that exerts its effects mainly through its incorporation into selenoproteins as the amino acid, selenocysteine. Twenty-five selenoprotein genes have been identified in humans and several selenoproteins are broadly classified as antioxidant enzymes. As progress is made on characterizing the individual members of this protein family, however, it is becoming clear that their properties and functions are quite diverse. This review summarizes recent insights into properties of individual selenoproteins such as tissue distribution, subcellular localization, and regulation of expression. Also discussed are potential roles the different selenoproteins play in human health and disease.
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Affiliation(s)
- M. A. Reeves
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawaii, 651 Ilalo Street, Honolulu, HI 96813 USA
| | - P. R. Hoffmann
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawaii, 651 Ilalo Street, Honolulu, HI 96813 USA
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Ogasawara MA, Zhang H. Redox regulation and its emerging roles in stem cells and stem-like cancer cells. Antioxid Redox Signal 2009; 11:1107-22. [PMID: 18999985 DOI: 10.1089/ars.2008.2308] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The existence of cancer stem cells has impelled the pursuit to understanding and characterizing this subset of cells, which are thought to be responsible for tumor recurrence and to contribute to therapy resistance. Recent studies suggest that cancer stem cells seem to possess properties similar to those of normal stem cells, revealing a possible therapeutic strategy/target. For this to be feasible, it is imperative to understand the relation between cancer cells, cancer stem cells, and normal stem cells. Cancer cells have been found to be in a state of redox imbalance, an alteration in the homeostasis between oxidants and antioxidants, resulting in increased oxidants within the cell. Studies have shown redox balance plays an important role in the maintenance of stem cell self-renewal and in differentiation. Very little is known about the redox status in cancer stem cells. In this review, we focus on the sites of oxidant generation and the regulation of redox status in cancer cells and stem cells. In addition, evidence that supports the involvement of redox homeostasis for stem cell self-renewal, differentiation, and survival are reviewed. Given the significance of redox in stem cells, we also discuss the possibility of exploiting the redox status in cancer stem cells as a novel therapeutic strategy.
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Affiliation(s)
- Marcia A Ogasawara
- Department of Molecular Pathology, The University of Texas MD Anderson Cancer Center, The University of Texas at Houston, Houston, Texas 77030, USA
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Brigelius-Flohé R, Kipp A. Glutathione peroxidases in different stages of carcinogenesis. Biochim Biophys Acta Gen Subj 2009; 1790:1555-68. [PMID: 19289149 DOI: 10.1016/j.bbagen.2009.03.006] [Citation(s) in RCA: 212] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2009] [Revised: 03/05/2009] [Accepted: 03/08/2009] [Indexed: 01/12/2023]
Abstract
Cancer cells produce high amounts of reactive oxygen species (ROS) and evade apoptosis. Hydroperoxides support proliferation, invasion, migration and angiogenesis, but at higher levels induce apoptosis, thus being pro- and anti-carcinogenic. Accordingly, glutathione peroxidases (GPxs) regulating hydroperoxide levels might have dual roles too. GPx1, clearly an antioxidant enzyme, is down-regulated in many cancer cells. Its main role would be prevention of cancer initiation by ROS-mediated DNA damage. GPx2 is up-regulated in cancer cells. GPx1/GPx2 double knockout mice develop colitis and intestinal cancer. However, GPx2 knockdown cancer cells grow better in vitro and in vivo probably reflecting the physiological role of GPx2 in intestinal mucosa homeostasis. GPx2 counteracts COX-2 expression and PGE(2) production, which explains its potential to inhibit migration and invasion of cultured cancer cells. Overexpression of GPx3 inhibits tumor growth and metastasis. GPx4 is decreased in cancer tissues. GPx4-overexpressing cancer cells have low COX-2 activity and tumors derived therefrom are smaller than from control cells and do not metastasize. Collectively, GPxs prevent cancer initiation by removing hydroperoxides. GPx4 inhibits but GPx2 supports growth of established tumors. Metastasis, but also apoptosis, is inhibited by all GPxs. GPx-mediated regulation of COX/LOX activities may be relevant to early stages of inflammation-mediated carcinogenesis.
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Affiliation(s)
- Regina Brigelius-Flohé
- Department Biochemistry of Micronutrients, German Institute of Human Nutrition Potsdam-Rehbruecke, Arthur-Scheunert-Allee 114-116, D-14558 Nuthetal, Germany.
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Thomas CG, Spyrou G. ERdj5 sensitizes neuroblastoma cells to endoplasmic reticulum stress-induced apoptosis. J Biol Chem 2009; 284:6282-90. [PMID: 19122239 DOI: 10.1074/jbc.m806189200] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Down-regulation of the unfolded protein response (UPR) can be therapeutically valuable in cancer treatment, and endoplasmic reticulum (ER)-resident chaperone proteins may thus be targets for developing novel chemotherapeutic strategies. ERdj5 is a novel ER chaperone that regulates the ER-associated degradation of misfolded proteins through its associations with EDEM and the ER stress sensor BiP. To investigate whether ERdj5 can regulate ER stress signaling pathways, we exposed neuroblastoma cells overexpressing ERdj5 to ER stress inducers. ERdj5 promoted apoptosis in tunicamycin, thapsigargin, and bortezomib-treated cells. To provide further evidence that ERdj5 induces ER stress-regulated apoptosis, we targeted Bcl-2 to ER of ERdj5-overexpressing cells. Targeting the Bcl-2 to ER prevented the apoptosis induced by ER stress inducers but not by non-ER stress apoptotic stimuli, suggesting induction of ER stress-regulated apoptosis by ERdj5. ERdj5 enhanced apoptosis by abolishing the ER stress-induced phosphorylation of eukaryotic translation initiation factor 2alpha (eIF2alpha) and the subsequent translational repression. ERdj5 was found to inhibit the eIF2alpha phosphorylation under ER stress through inactivating the pancreatic endoplasmic reticulum kinase. The compromised integrated stress response observed in ERdj5-overexpressing ER-stressed cells due to repressed eIF2alpha phosphorylation correlated with impaired neuroblastoma cell resistance under ER stress. These results demonstrate that ERdj5 decreases neuroblastoma cell survival by down-regulating the UPR, raising the possibility that this protein could be a target for anti-tumor approaches.
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Affiliation(s)
- Christophoros G Thomas
- Department of Biosciences and Nutrition, Karolinska Institute, S-14157 Huddinge, Sweden.
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Peters U, Chatterjee N, Hayes RB, Schoen RE, Wang Y, Chanock SJ, Foster CB. Variation in the selenoenzyme genes and risk of advanced distal colorectal adenoma. Cancer Epidemiol Biomarkers Prev 2008; 17:1144-54. [PMID: 18483336 DOI: 10.1158/1055-9965.epi-07-2947] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Epidemiologic and animal studies provide evidence for a chemopreventive effect of selenium on colorectal cancer, which may be mediated by the antioxidative and anti-inflammatory properties of selenoenzymes. We therefore investigated whether genetic variants in selenoenzymes abundantly expressed in the colon are associated with advanced colorectal adenoma, a cancer precursor. METHODS Cases with a left-sided advanced adenoma (n = 772) and matched controls (n = 777) screen negative for polyps based on sigmoidoscopy examination were randomly selected from participants in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial. The underlying genetic variation was determined by resequencing. We genotyped 44 tagging single nucleotide polymorphisms (SNP) in six genes [glutathione peroxidase 1-4 (GPX1, GPX2, GPX3, and GPX4), selenoprotein P (SEPP1), and thioredoxin reductase 1 (TXNRD1)] to efficiently predict common variation across these genes. RESULTS Four variants in SEPP1 were significantly associated with advanced adenoma risk. A rare variant in the 5' region of SEPP1 (-4166C>G) was present in nine cases but in none of the controls (exact P = 0.002). Three SNPs located in the 3' region of SEPP1, which is overlapping with the promoter region of an antisense transcript, were significantly associated with adenoma risk: homozygotes at two SEPP1 loci (31,174 bp 3' of STP A>G and 43,881 bp 3' of STP G>A) were associated with increased adenoma risk [odds ratio (OR), 1.48; 95% confidence interval (95% CI), 1.00-2.19 and OR, 1.53; 95% CI, 1.05-2.22, respectively] and the variant SEPP1 44,321 bp 3' of STP C>T was associated with a reduced adenoma risk (CT versus CC OR, 0.85; 95% CI, 0.63-1.15). Furthermore, we observed a significant 80% reduction for advanced colorectal adenoma risk for carriers of the variant allele at TXNRD1 IVS1-181C>G (OR, 0.20; 95% CI, 0.07-0.55; P trend = 0.004). Consistent with the individual SNP results, we observed a significant overall association with adenoma risk for SEPP1 and TXNRD1 (global P = 0.02 and 0.008, respectively) but not for the four GPX genes. CONCLUSION Our study suggests that genetic variants at or near the SEPP1 and TXNRD1 loci may be associated with advanced colorectal adenoma. As this is the first study to comprehensively investigate this hypothesis, confirmation in independent study populations is needed.
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Affiliation(s)
- Ulrike Peters
- Public Health Science, Fred Hutchinson Cancer Research Center, PO Box 19024, Seattle, WA 98109-1024, USA.
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Gladyshev VN, Hatfield DL. Analysis of selenocysteine-containing proteins. ACTA ACUST UNITED AC 2008; Chapter 3:Unit 3.8. [PMID: 18429173 DOI: 10.1002/0471140864.ps0308s20] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Representatives of three primary life domains--bacteria, archaea, and eukaryotes--possess specific selenium-containing proteins. The majority of naturally occurring selenoproteins contain an amino acid, selenocysteine, that is incorporated into protein in response to the code word UGA. The presence of selenium in natural selenoproteins and in proteins in which this element is introduced by chemical or biological manipulations provides additional opportunities for characterizing structure, function, and mechanism of action. This unit provides an overview of known selenocysteine-containing proteins, examples of targeted incorporation of selenium into proteins, and methods specific for selenoprotein identification and characterization.
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Selenius M, Fernandes AP, Brodin O, Björnstedt M, Rundlöf AK. Treatment of lung cancer cells with cytotoxic levels of sodium selenite: Effects on the thioredoxin system. Biochem Pharmacol 2008; 75:2092-9. [DOI: 10.1016/j.bcp.2008.02.028] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2008] [Revised: 02/20/2008] [Accepted: 02/20/2008] [Indexed: 11/28/2022]
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Stemm DN, Tharappel JC, Lehmler HJ, Srinivasan C, Morris JS, Spate VL, Robertson LW, Spear BT, Glauert HP. Effect of dietary selenium on the promotion of hepatocarcinogenesis by 3,3', 4,4'-tetrachlorobiphenyl and 2,2', 4,4', 5,5'-hexachlorobiphenyl. Exp Biol Med (Maywood) 2008; 233:366-76. [PMID: 18296742 DOI: 10.3181/0708-rm-211] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Polychlorinated biphenyls (PCBs) are persistent organic pollutants that have promoting activity in the liver. PCBs induce oxidative stress, which may influence carcinogenesis. Epidemiological studies strongly suggest an inverse relationship between dietary selenium (Se) and cancer. Despite evidence linking Se deficiency to hepatocellular carcinoma and liver necrosis, the underlying mechanisms for Se cancer protection in the liver remain to be determined. We examined the effect of dietary Se on the tumor promoting activities of two PCBs congeners, 3,3', 4,4'-tetrachlorobiphenyl (PCB-77) and 2,2', 4,4', 5,5'-hexachlorobiphenyl (PCB-153) using a 2-stage carcinogenesis model. An AIN-93 torula yeast-based purified diet containing 0.02 (deficient), 0.2 (adequate), or 2.0 mg (supplemental) selenium/kg diet was fed to Sprague-Dawley female rats starting ten days after administering a single dose of diethylnitrosamine (150 mg/kg). After being fed the selenium diets for 3 weeks, rats received four i.p. injections of either PCB-77 or PCB-153 (150 micromol/kg) administered every 14 days. The number of placental glutathione S-transferase (PGST)-positive foci per cm(3) and per liver among the PCB-77-treated rats was increased as the Se dietary level increased. Unlike PCB-77, rats receiving PCB-153 did not show the same Se dose-response effect; nevertheless, Se supplementation did not confer protection against foci development. However, the 2.0 ppm Se diet reduced the mean focal volume, indicating a possible protective effect by inhibiting progression of preneoplastic lesions into larger foci. Cell proliferation was not inhibited by Se in the liver of the PCB-treated groups. Se did not prevent the PCB-77-induced decrease of hepatic Se and associated reduction in glutathione peroxidase (GPx) activity. In contrast, thioredoxin reductase (TrxR) activity was not affected by the PCBs treatment or by Se supplementation. These findings indicate that Se does not inhibit the number of PGST-positive foci induced during promotion by PCBs, but that the size of the lesions may be inhibited. The effects of Se on altered hepatic foci do not correlate with its effects on GPx and TrxR.
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Affiliation(s)
- Divinia N Stemm
- Graduate Center for Nutritional Sciences, 222 Funkhouser Building, University of Kentucky, Lexington, KY 40506-0054, USA
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Abstract
AIM OF STUDY Reactive oxygen species have been shown to be initiators/promotors of tumorigenesis. Because evidence supports the role of increased oxidative stress in solid tumors, we sought to establish this relationship in neuroblastoma (NB). The aim of the study was to investigate the extent of oxidative DNA damage and antioxidative status in a progressive animal model of human NB. METHODS Tumors were induced in the left kidneys of nude mice by the injection of cultured human NB cells (10(6)). Blood was collected from tumor-bearing mice and controls at 2, 4, and 6 weeks. Peripheral blood leukocyte oxidative DNA damage was determined using single-cell gel electrophoresis (comet assay), and plasma antioxidant capacity was assessed by the Trolox equivalent antioxidant capacity method. MAIN RESULTS Levels of oxidative DNA damage in peripheral blood leukocytes of NB-bearing mice were increased by 166%, 110%, and 87% as compared with healthy controls at 2, 4, and 6 weeks, respectively. Plasma total antioxidant values for tumor-bearing mice were not significantly different from control mice. CONCLUSIONS Our results indicate an increase of oxidative stress in an animal model of human NB, especially in the early stages of growth. Yet, we did not observe an appreciable response in plasma antioxidant activity. Because an altered redox status has been implicated in tumor maintenance and progression, these findings support the notion of a complex oxidant-antioxidant imbalance contributing to NB growth.
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Wessjohann LA, Schneider A, Abbas M, Brandt W. Selenium in chemistry and biochemistry in comparison to sulfur. Biol Chem 2008; 388:997-1006. [PMID: 17937613 DOI: 10.1515/bc.2007.138] [Citation(s) in RCA: 179] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
What makes selenoenzymes--seen from a chemist's view--so special that they cannot be substituted by just more analogous or adapted sulfur proteins? This review compiles and compares physicochemical properties of selenium and sulfur, synthetic routes to selenocysteine (Sec) and its peptides, and comparative studies of relevant thiols and selenols and their (mixed) dichalcogens, required to understand the special role of selenium in selenoproteins on the atomic molecular level. The biochemically most relevant differences are the higher polarizability of Se- and the lower pKa of SeH. The latter has a strikingly different pH-dependence than thiols, with selenols being active at much lower pH. Finally, selected typical enzymatic mechanisms which involve selenocysteine are critically discussed, also in view of the authors' own results.
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Affiliation(s)
- Ludger A Wessjohann
- Department of Bioorganic Chemistry, Leibniz Institute of Plant Biochemistry, Weinberg 3, D-06120 Halle/Saale, Germany.
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Abstract
Glutathione peroxidase-1 (GPX1) represents the first identified mammalian selenoprotein, and our understanding in the metabolic regulation and function of this abundant selenoenzyme has greatly advanced during the past decade. Selenocysteine insertion sequence-associating factors, adenosine, and Abl and Arg tyrosine kinases are potent, Se-independent regulators of GPX1 gene, protein, and activity. Overwhelming evidences have been generated using the GPX1 knockout and transgenic mice for the in vivo protective role of GPX1 in coping with oxidative injury and death mediated by reactive oxygen species. However, GPX1 exerts an intriguing dual role in reactive nitrogen species (RNS)-related oxidative stress. Strikingly, knockout of GPX1 rendered mice resistant to toxicities of drugs including acetaminophen and kainic acid, known as RNS inducers. Intracellular and tissue levels of GPX1 activity affect apoptotic signaling pathway, protein kinase phosphorylation, and oxidant-mediated activation of NFkappaB. Data are accumulating to link alteration or abnormality of GPX1 expression to etiology of cancer, cardiovascular disease, neurodegeneration, autoimmune disease, and diabetes. Future research should focus on the mechanism of GPX1 in the pathogeneses and potential applications of GPX1 manipulation in the treatment of these disorders.
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Affiliation(s)
- Xin Gen Lei
- Department of Animal Science, Cornell University, Ithaca, NY 14853, USA.
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Cunnea P, Fernandes AP, Capitanio A, Eken S, Spyrou G, Björnstedt M. Increased expression of specific thioredoxin family proteins; a pilot immunohistochemical study on human hepatocellular carcinoma. Int J Immunopathol Pharmacol 2007; 20:17-24. [PMID: 17346424 DOI: 10.1177/039463200702000103] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Hepatocellular Carcinoma (HCC) is one of the most frequent cancers worldwide, however, prognosis remains poor following its discovery. We investigate the Thioredoxin superfamily of proteins as diagnostic markers for HCC. Furthermore, we delineate possible roles of the endoplasmic reticulum member of the superfamily, ERdj5, in carcinogenesis. Using antibodies against Thioredoxin 1, Thioredoxin Reductase 1 and ERdj5, we performed immunohistochemistry on paraffin embedded liver biopsy sections from HCC patients. All three redox proteins exhibited elevated expression levels in tumor tissue compared to internal control, with ERdj5 showing a remarkable 3-fold increase. In vitro cell viability experiments using Hepatocellular Carcinoma HuH7 cells treated with ERdj5 small interfering RNA showed that ERdj5 knockdown cells exhibited less resistance to Doxorubicin (chemotherapy drug), but more resistance to Tunicamycin (Endoplasmic Stress inducer), compared to control cells. In conclusion, we introduce members of the Thioredoxin superfamily as possible immunohistochemical markers in the diagnostics of hepatocellular carcinoma and indicate a potential defensive role for ERdj5 in chemotherapeutic drug resistance.
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Affiliation(s)
- P Cunnea
- Department of Biosciences and Nutrition at NOVUM, Karolinska Institutet, Stockholm, Sweden.
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Rundlöf AK, Fernandes AP, Selenius M, Babic M, Shariatgorji M, Nilsonne G, Ilag LL, Dobra K, Björnstedt M. Quantification of alternative mRNA species and identification of thioredoxin reductase 1 isoforms in human tumor cells. Differentiation 2007; 75:123-32. [PMID: 17316382 DOI: 10.1111/j.1432-0436.2006.00121.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The human selenoenzyme thioredoxin reductase 1 (TrxR1) is a very important enzyme for cell growth, differentiation, and the defense against oxidative stress. Several studies have shown that TrxR1 is up-regulated in tumor cells. The regulation of TrxR1 is very complex and involves the expression of different transcript forms of mRNA. We have, by quantitative polymerase chain reaction, investigated the total expression of TrxR1 mRNA and quantified the expression of alternative mRNA forms (alpha1/2, alpha6, alpha7/8, alpha10/11, alpha13, gamma2-4, and beta1) in six different human malignant mesothelioma cell lines of epithelioid, sarcomatoid, or mixed phenotype. The most abundant alpha-form was surprisingly alpha1/2 and not the expected alpha7/8. Selenium treatment resulted in increased expression of all alpha-variants, except the alpha10/11, where the levels were unaffected. The expression of protein isoforms was studied and the less abundant forms TrxR1v.2, TrxR1v.3, and TrxR1v.5 were detected in cell lysates and in human tumor tissue, using specific peptide antibodies. Furthermore, TrxR1v.3 and TrxR1v.5, previously not identified in human cells, were detected by mass spectrometry. Our data show differential expression of TrxR1 mRNA forms in malignant mesothelioma of different phenotype, and investigation of alternative transcript variants of TrxR1 could be a valuable tool in the diagnostics and characterization of tumors.
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Affiliation(s)
- Anna-Klara Rundlöf
- Department of Laboratory Medicine, Division of Pathology F46, Karolinska Institute, Karolinska University Hospital, Huddinge, SE-141 86 Stockholm, Sweden.
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Abstract
Se is an unusual trace element in having its own codon in mRNA that specifies its insertion into selenoproteins as selenocysteine (SeCys), by means of a mechanism requiring a large SeCys-insertion complex. This exacting insertion machinery for selenoprotein production has implications for the Se requirements for cancer prevention. If Se may protect against cancer, an adequate intake of Se is desirable. However, the level of intake in Europe and some parts of the world is not adequate for full expression of protective selenoproteins. The evidence for Se as a cancer preventive agent includes that from geographic, animal, prospective and intervention studies. Newly-published prospective studies on oesophageal, gastric-cardia and lung cancer have reinforced previous evidence, which is particularly strong for prostate cancer. Interventions with Se have shown benefit in reducing the risk of cancer incidence and mortality in all cancers combined, and specifically in liver, prostate, colo-rectal and lung cancers. The effect seems to be strongest in those individuals with the lowest Se status. As the level of Se that appears to be required for optimal effect is higher than that previously understood to be required to maximise the activity of selenoenzymes, the question has been raised as to whether selenoproteins are involved in the anti-cancer process. However, recent evidence showing an association between Se, reduction of DNA damage and oxidative stress together with data showing an effect of selenoprotein genotype on cancer risk implies that selenoproteins are indeed implicated. The likelihood of simultaneous and consecutive effects at different cancer stages still allows an important role for anti-cancer Se metabolites such as methyl selenol formed from γ-glutamyl-selenomethyl-SeCys and selenomethyl-SeCys, components identified in certain plants and Se-enriched yeast that have anti-cancer effects. There is some evidence that Se may affect not only cancer risk but also progression and metastasis. Current primary and secondary prevention trials of Se are underway in the USA, including the Selenium and Vitamin E Cancer Prevention Trial (SELECT) relating to prostate cancer, although a large European trial is still desirable given the likelihood of a stronger effect in populations of lower Se status.
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Affiliation(s)
- Margaret P Rayman
- Division of Nutrition, Dietetics and Food, School of Biomedical and Molecular Sciences, University of Surrey, Guildford, UK.
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Bruzelius K, Hoac T, Sundler R, Onning G, Akesson B. Occurrence of Selenoprotein Enzyme Activities and mRNA in Bovine Mammary Tissue. J Dairy Sci 2007; 90:918-27. [PMID: 17235168 DOI: 10.3168/jds.s0022-0302(07)71575-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
To elucidate the possible role of selenoproteins for milk formation and mammary gland physiology, the activities of selenoprotein enzymes and the expression of selenoprotein genes were studied in the bovine mammary gland. Messenger RNA was demonstrated for selenoprotein P, thioredoxin reductase 1, and for glutathione peroxidase (GPx) 1, 3, and 4. Significant differences in mRNA expression between the cows were seen for GPx 1 and GPx 3. The enzyme activity of glutathione peroxidase varied approximately 16-fold among cows, and the activity of thioredoxin reductase and the concentration of soluble Se varied approximately 6-fold among cows. There were positive correlations between glutathione peroxidase activity, thioredoxin reductase activity, and soluble Se, the correlation between glutathione peroxidase activity and soluble Se being the strongest. Furthermore, selenoprotein P expression correlated with GPx 1 mRNA expression and with soluble Se. There was also a correlation between glutathione peroxidase activity and the mRNA expression of GPx 1. The general conclusion from the data was that the activity of glutathione peroxidase and thioredoxin reductase and the mRNA expression of selenoprotein P and GPx 1 and 3 were influenced by Se status, but the expression of GPx 4 and thioredoxin reductase 1 were not. These results indicate that the Se status in mammary tissue is an important regulator of selenoprotein activity and expression, but that other factors are also in operation.
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Affiliation(s)
- K Bruzelius
- Biomedical Nutrition, Faculty of Engineering LTH, Lund University, Lund, Sweden
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