1
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Liu S, Liao Y, Chen Y, Yang H, Hu Y, Chen Z, Fu S, Wu J. Effect of triple therapy with low-dose total body irradiation and hypo-fractionated radiation plus anti-programmed cell death protein 1 blockade on abscopal antitumor immune responses in breast cancer. Int Immunopharmacol 2023; 117:110026. [PMID: 36934673 DOI: 10.1016/j.intimp.2023.110026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Revised: 03/05/2023] [Accepted: 03/09/2023] [Indexed: 03/19/2023]
Abstract
Immunostimulatory effects of radiotherapy can be synergistically augmented with immune checkpoint blockade to act both on irradiated tumor lesions and distant, non-irradiated tumor sites. Our hypothesis was that low-dose total body irradiation (L-TBI) combined with hypo-fractionated radiotherapy (H-RT) and anti-programmed cell death protein 1 (aPD-1) checkpoint blockade would enhance the systemic immune response. We tested the efficacy of this triple therapy (L-TBI + H-RT + aPD-1) in BALB/c mice with bilateral breast cancer xenografts. The L-TBI dose was 0.1 Gy. The primary tumor was treated with H-RT (8 Gy × 3). The PD-1 monoclonal antibody was injected intraperitoneally, and the secondary tumors not receiving H-RT were monitored for response. The triple therapy significantly delayed both primary and secondary tumor growths, improved survival rates, and reduced the number of lung metastasis lesions. It increased the activated dendritic and CD8+ T cell populations and reduced the infiltration of myeloid-derived suppressor cells in the secondary tumor microenvironment relative to other groups. Thus, L-TBI could be a potential therapeutic modality, and when combined with H-RT and aPD-1, the therapeutic effect could be enhanced significantly.
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Affiliation(s)
- Shuya Liu
- Department of Oncology, The Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan, China
| | - Yin Liao
- Department of Oncology, The Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan, China
| | - Yao Chen
- Department of Oncology, The Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan, China
| | - Hanshan Yang
- Department of Oncology, The Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan, China
| | - Yuru Hu
- Department of Oncology, The Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan, China
| | - Zhuo Chen
- Department of Oncology, The Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan, China
| | - Shaozhi Fu
- Department of Oncology, The Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan, China.
| | - Jingbo Wu
- Department of Oncology, The Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan, China; Nuclear Medicine and Molecular Imaging Key Laboratory of Sichuan Province, Luzhou, Sichuan, China; Academician (Expert) Workstation of Sichuan Province, Luzhou, Sichuan, China.
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2
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Ionizing Radiation and Translation Control: A Link to Radiation Hormesis? Int J Mol Sci 2020; 21:ijms21186650. [PMID: 32932812 PMCID: PMC7555331 DOI: 10.3390/ijms21186650] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 09/04/2020] [Indexed: 02/06/2023] Open
Abstract
Protein synthesis, or mRNA translation, is one of the most energy-consuming functions in cells. Translation of mRNA into proteins is thus highly regulated by and integrated with upstream and downstream signaling pathways, dependent on various transacting proteins and cis-acting elements within the substrate mRNAs. Under conditions of stress, such as exposure to ionizing radiation, regulatory mechanisms reprogram protein synthesis to translate mRNAs encoding proteins that ensure proper cellular responses. Interestingly, beneficial responses to low-dose radiation exposure, known as radiation hormesis, have been described in several models, but the molecular mechanisms behind this phenomenon are largely unknown. In this review, we explore how differences in cellular responses to high- vs. low-dose ionizing radiation are realized through the modulation of molecular pathways with a particular emphasis on the regulation of mRNA translation control.
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3
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Ionizing Radiation-Induced Epigenetic Modifications and Their Relevance to Radiation Protection. Int J Mol Sci 2020; 21:ijms21175993. [PMID: 32825382 PMCID: PMC7503247 DOI: 10.3390/ijms21175993] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2020] [Revised: 08/15/2020] [Accepted: 08/17/2020] [Indexed: 12/12/2022] Open
Abstract
The present system of radiation protection assumes that exposure at low doses and/or low dose-rates leads to health risks linearly related to the dose. They are evaluated by a combination of epidemiological data and radiobiological models. The latter imply that radiation induces deleterious effects via genetic mutation caused by DNA damage with a linear dose-dependence. This picture is challenged by the observation of radiation-induced epigenetic effects (changes in gene expression without altering the DNA sequence) and of non-linear responses, such as non-targeted and adaptive responses, that in turn can be controlled by gene expression networks. Here, we review important aspects of the biological response to ionizing radiation in which epigenetic mechanisms are, or could be, involved, focusing on the possible implications to the low dose issue in radiation protection. We examine in particular radiation-induced cancer, non-cancer diseases and transgenerational (hereditary) effects. We conclude that more realistic models of radiation-induced cancer should include epigenetic contribution, particularly in the initiation and progression phases, while the impact on hereditary risk evaluation is expected to be low. Epigenetic effects are also relevant in the dispute about possible "beneficial" effects at low dose and/or low dose-rate exposures, including those given by the natural background radiation.
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4
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Liu X, Liu Z, Wang D, Han Y, Hu S, Xie Y, Liu Y, Zhu M, Guan H, Gu Y, Zhou PK. Effects of low dose radiation on immune cells subsets and cytokines in mice. Toxicol Res (Camb) 2020; 9:249-262. [PMID: 32670556 DOI: 10.1093/toxres/tfaa017] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Revised: 03/07/2020] [Accepted: 03/30/2020] [Indexed: 12/23/2022] Open
Abstract
Whole-body exposure to low-dose radiation due to diagnostic imaging procedures, occupational hazards and radiation accidents is a source of concern. In this study, we analyzed the effects of single and long-term low-dose irradiation on the immune system. Male Balb/c mice received a single whole-body dose of irradiation (0.01, 0.05, 0.2, 0.5 or 1 Gy). For long-term irradiation, mice were irradiated 10 times (total dose of 0.2, 0.5 or 1 Gy) over a period of 6 weeks. Two days after single or long-term irradiation, the numbers of splenic macrophages, natural killer cells and dendritic cells were reduced, and the spleen organ coefficient was decreased. At 2 Days after long-term low-dose irradiation, the number of white blood cells in the peripheral blood of the mice decreased. Between 7 and 14 Days after long-term low-dose irradiation, the number of immune cells in the thymus and spleen began to increase and then stabilized. Th1/Th2 cytokines and reactive oxygen species-related proteins first decreased and then increased to a plateau. Our results show a significant difference in the effects of single and long-term low-dose irradiation on the immune system.
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Affiliation(s)
- Xiaochang Liu
- School of Public Health, University of South China, Zhengxiang District, Hengyang, Hunan Province 421001, P. R. China.,Beijing Key Laboratory for Radiobiology, Beijing Institute of Radiation Medicine, Haidian District, Beijing 100850, P. R. China
| | - Zheng Liu
- School of Public Health, University of South China, Zhengxiang District, Hengyang, Hunan Province 421001, P. R. China.,Beijing Key Laboratory for Radiobiology, Beijing Institute of Radiation Medicine, Haidian District, Beijing 100850, P. R. China
| | - Duo Wang
- Beijing Key Laboratory for Radiobiology, Beijing Institute of Radiation Medicine, Haidian District, Beijing 100850, P. R. China
| | - Yang Han
- School of Public Health, University of South China, Zhengxiang District, Hengyang, Hunan Province 421001, P. R. China.,Beijing Key Laboratory for Radiobiology, Beijing Institute of Radiation Medicine, Haidian District, Beijing 100850, P. R. China
| | - Sai Hu
- School of Public Health, University of South China, Zhengxiang District, Hengyang, Hunan Province 421001, P. R. China.,Beijing Key Laboratory for Radiobiology, Beijing Institute of Radiation Medicine, Haidian District, Beijing 100850, P. R. China
| | - Ying Xie
- Key Laboratory of Molecular Epidemiology of Hunan Province, School of Medicine, Hunan Normal University, Yuelu District, Changsha 410013, P. R. China
| | - Yike Liu
- Institute for Chemical Carcinogenesis, State Key Laboratory of Respiratory Disease, Guangzhou Medical University, 195 Dongfeng W Rd, Yuexiu District, Guangzhou 511436, P. R. China
| | - Maoxiang Zhu
- Beijing Key Laboratory for Radiobiology, Beijing Institute of Radiation Medicine, Haidian District, Beijing 100850, P. R. China
| | - Hua Guan
- Beijing Key Laboratory for Radiobiology, Beijing Institute of Radiation Medicine, Haidian District, Beijing 100850, P. R. China
| | - Yongqing Gu
- School of Public Health, University of South China, Zhengxiang District, Hengyang, Hunan Province 421001, P. R. China.,Beijing Key Laboratory for Radiobiology, Beijing Institute of Radiation Medicine, Haidian District, Beijing 100850, P. R. China
| | - Ping-Kun Zhou
- School of Public Health, University of South China, Zhengxiang District, Hengyang, Hunan Province 421001, P. R. China.,Beijing Key Laboratory for Radiobiology, Beijing Institute of Radiation Medicine, Haidian District, Beijing 100850, P. R. China
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5
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The LNT model for cancer induction is not supported by radiobiological data. Chem Biol Interact 2019; 301:34-53. [PMID: 30763552 DOI: 10.1016/j.cbi.2019.01.013] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2018] [Revised: 01/07/2019] [Accepted: 01/09/2019] [Indexed: 12/18/2022]
Abstract
The hallmarks of cancer have been the focus of much research and have influenced the development of risk models for radiation-induced cancer. However, natural defenses against cancer, which constitute the hallmarks of cancer prevention, have largely been neglected in developing cancer risk models. These natural defenses are enhanced by low doses and dose rates of ionizing radiation, which has aided in the continuation of human life over many generations. Our natural defenses operate at the molecular, cellular, tissue, and whole-body levels and include epigenetically regulated (epiregulated) DNA damage repair and antioxidant production, selective p53-independent apoptosis of aberrant cells (e.g. neoplastically transformed and tumor cells), suppression of cancer-promoting inflammation, and anticancer immunity (both innate and adaptive components). This publication reviews the scientific bases for the indicated cancer-preventing natural defenses and evaluates their implication for assessing cancer risk after exposure to low radiation doses and dose rates. Based on the extensive radiobiological evidence reviewed, it is concluded that the linear-no-threshold (LNT) model (which ignores natural defenses against cancer), as it relates to cancer risk from ionizing radiation, is highly implausible. Plausible models include dose-threshold and hormetic models. More research is needed to establish when a given model (threshold, hormetic, or other) applies to a given low-dose-radiation exposure scenario.
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6
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Wang Y, Bannister LA, Sebastian S, Le Y, Ismail Y, Didychuk C, Richardson RB, Flegal F, Paterson LC, Causey P, Fawaz A, Wyatt H, Priest N, Klokov D. Low-dose radiobiology program at Canadian nuclear laboratories: past, present, and future. Int J Radiat Biol 2019; 95:1361-1371. [DOI: 10.1080/09553002.2018.1562252] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Yi Wang
- Radiobiology and Health, Canadian Nuclear Laboratories, Chalk River, Canada
- Department of Biochemistry Microbiology and Immunology, University of Ottawa, Ottawa, Canada
| | - Laura A. Bannister
- Radiobiology and Health, Canadian Nuclear Laboratories, Chalk River, Canada
- Department of Biochemistry Microbiology and Immunology, University of Ottawa, Ottawa, Canada
| | - Soji Sebastian
- Radiobiology and Health, Canadian Nuclear Laboratories, Chalk River, Canada
| | - Yevgeniya Le
- Radiobiology and Health, Canadian Nuclear Laboratories, Chalk River, Canada
- Department of Biochemistry Microbiology and Immunology, University of Ottawa, Ottawa, Canada
| | - Youssef Ismail
- Radiobiology and Health, Canadian Nuclear Laboratories, Chalk River, Canada
| | - Candice Didychuk
- Radiobiology and Health, Canadian Nuclear Laboratories, Chalk River, Canada
| | - Richard B. Richardson
- Radiobiology and Health, Canadian Nuclear Laboratories, Chalk River, Canada
- McGill Medical Physics Unit, Cedars Cancer Centre–Glen Site, Montreal, Canada
| | - Farrah Flegal
- Radiobiology and Health, Canadian Nuclear Laboratories, Chalk River, Canada
| | - Laura C. Paterson
- Radiobiology and Health, Canadian Nuclear Laboratories, Chalk River, Canada
| | - Patrick Causey
- Radiobiology and Health, Canadian Nuclear Laboratories, Chalk River, Canada
| | - Ali Fawaz
- Radiobiology and Health, Canadian Nuclear Laboratories, Chalk River, Canada
| | - Heather Wyatt
- Radiobiology and Health, Canadian Nuclear Laboratories, Chalk River, Canada
| | | | - Dmitry Klokov
- Radiobiology and Health, Canadian Nuclear Laboratories, Chalk River, Canada
- Department of Biochemistry Microbiology and Immunology, University of Ottawa, Ottawa, Canada
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7
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Cortese F, Klokov D, Osipov A, Stefaniak J, Moskalev A, Schastnaya J, Cantor C, Aliper A, Mamoshina P, Ushakov I, Sapetsky A, Vanhaelen Q, Alchinova I, Karganov M, Kovalchuk O, Wilkins R, Shtemberg A, Moreels M, Baatout S, Izumchenko E, de Magalhães JP, Artemov AV, Costes SV, Beheshti A, Mao XW, Pecaut MJ, Kaminskiy D, Ozerov IV, Scheibye-Knudsen M, Zhavoronkov A. Vive la radiorésistance!: converging research in radiobiology and biogerontology to enhance human radioresistance for deep space exploration and colonization. Oncotarget 2018; 9:14692-14722. [PMID: 29581875 PMCID: PMC5865701 DOI: 10.18632/oncotarget.24461] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Accepted: 01/31/2018] [Indexed: 12/12/2022] Open
Abstract
While many efforts have been made to pave the way toward human space colonization, little consideration has been given to the methods of protecting spacefarers against harsh cosmic and local radioactive environments and the high costs associated with protection from the deleterious physiological effects of exposure to high-Linear energy transfer (high-LET) radiation. Herein, we lay the foundations of a roadmap toward enhancing human radioresistance for the purposes of deep space colonization and exploration. We outline future research directions toward the goal of enhancing human radioresistance, including upregulation of endogenous repair and radioprotective mechanisms, possible leeways into gene therapy in order to enhance radioresistance via the translation of exogenous and engineered DNA repair and radioprotective mechanisms, the substitution of organic molecules with fortified isoforms, and methods of slowing metabolic activity while preserving cognitive function. We conclude by presenting the known associations between radioresistance and longevity, and articulating the position that enhancing human radioresistance is likely to extend the healthspan of human spacefarers as well.
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Affiliation(s)
- Franco Cortese
- Biogerontology Research Foundation, London, UK
- Department of Biomedical and Molecular Sciences, Queen's University School of Medicine, Queen's University, Kingston, Ontario, Canada
| | - Dmitry Klokov
- Canadian Nuclear Laboratories, Chalk River, Ontario, Canada
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Ontario, Canada
| | - Andreyan Osipov
- Insilico Medicine, Inc., Emerging Technology Centers, Johns Hopkins University, Baltimore, MD, USA
- State Research Center - Burnasyan Federal Medical Biophysical Center of Federal Medical Biological Agency, Moscow, Russia
- Moscow Institute of Physics and Technology, Dolgoprudny, Russia
| | - Jakub Stefaniak
- Biogerontology Research Foundation, London, UK
- Nuffield Department of Medicine, Target Discovery Institute, University of Oxford, Oxford, UK
| | - Alexey Moskalev
- Moscow Institute of Physics and Technology, Dolgoprudny, Russia
- Laboratory of Molecular Radiobiology and Gerontology, Institute of Biology of Komi Science Center of Ural Branch of Russian Academy of Sciences, Syktyvkar, Russia
- Engelhardt Institute of Molecular Biology of Russian Academy of Sciences, Moscow, Russia
| | - Jane Schastnaya
- Insilico Medicine, Inc., Emerging Technology Centers, Johns Hopkins University, Baltimore, MD, USA
| | - Charles Cantor
- Boston University, Department of Biomedical Engineering, Boston, MA, USA
| | - Alexander Aliper
- Insilico Medicine, Inc., Emerging Technology Centers, Johns Hopkins University, Baltimore, MD, USA
- Laboratory of Bioinformatics, D. Rogachev Federal Medical Research Center of Pediatric Hematology, Oncology and Immunology, Moscow, Russia
| | - Polina Mamoshina
- Insilico Medicine, Inc., Emerging Technology Centers, Johns Hopkins University, Baltimore, MD, USA
- Computer Science Department, University of Oxford, Oxford, UK
| | - Igor Ushakov
- State Research Center - Burnasyan Federal Medical Biophysical Center of Federal Medical Biological Agency, Moscow, Russia
| | - Alex Sapetsky
- State Research Center - Burnasyan Federal Medical Biophysical Center of Federal Medical Biological Agency, Moscow, Russia
| | - Quentin Vanhaelen
- Insilico Medicine, Inc., Emerging Technology Centers, Johns Hopkins University, Baltimore, MD, USA
| | - Irina Alchinova
- Laboratory of Physicochemical and Ecological Pathophysiology, Institute of General Pathology and Pathophysiology, Moscow, Russia
- Research Institute for Space Medicine, Federal Medical Biological Agency, Moscow, Russia
| | - Mikhail Karganov
- Laboratory of Physicochemical and Ecological Pathophysiology, Institute of General Pathology and Pathophysiology, Moscow, Russia
| | - Olga Kovalchuk
- Canada Cancer and Aging Research Laboratories, Ltd., Lethbridge, Alberta, Canada
- University of Lethbridge, Lethbridge, Alberta, Canada
| | - Ruth Wilkins
- Environmental and Radiation and Health Sciences Directorate, Health Canada, Ottawa, Ontario, Canada
| | - Andrey Shtemberg
- Laboratory of Extreme Physiology, Institute of Medical and Biological Problems RAS, Moscow, Russia
| | - Marjan Moreels
- Radiobiology Unit, Interdisciplinary Biosciences, Institute for Environment, Health and Safety, Belgian Nuclear Research Centre, (SCK·CEN), Mol, Belgium
| | - Sarah Baatout
- Radiobiology Unit, Interdisciplinary Biosciences, Institute for Environment, Health and Safety, Belgian Nuclear Research Centre, (SCK·CEN), Mol, Belgium
- Department of Molecular Biotechnology, Ghent University, Ghent, Belgium
| | - Evgeny Izumchenko
- Insilico Medicine, Inc., Emerging Technology Centers, Johns Hopkins University, Baltimore, MD, USA
- The Johns Hopkins University, School of Medicine, Department of Otolaryngology, Head and Neck Cancer Research, Baltimore, MD, USA
| | - João Pedro de Magalhães
- Biogerontology Research Foundation, London, UK
- Integrative Genomics of Ageing Group, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, UK
| | - Artem V. Artemov
- Insilico Medicine, Inc., Emerging Technology Centers, Johns Hopkins University, Baltimore, MD, USA
| | | | - Afshin Beheshti
- Wyle Laboratories, Space Biosciences Division, NASA Ames Research Center, Mountain View, CA, USA
- Division of Hematology/Oncology, Molecular Oncology Research Institute, Tufts Medical Center, Boston, MA, USA
| | - Xiao Wen Mao
- Department of Basic Sciences, Division of Biomedical Engineering Sciences (BMES), Loma Linda University, Loma Linda, CA, USA
| | - Michael J. Pecaut
- Department of Basic Sciences, Division of Biomedical Engineering Sciences (BMES), Loma Linda University, Loma Linda, CA, USA
| | - Dmitry Kaminskiy
- Biogerontology Research Foundation, London, UK
- Deep Knowledge Life Sciences, London, UK
| | - Ivan V. Ozerov
- Insilico Medicine, Inc., Emerging Technology Centers, Johns Hopkins University, Baltimore, MD, USA
- State Research Center - Burnasyan Federal Medical Biophysical Center of Federal Medical Biological Agency, Moscow, Russia
| | | | - Alex Zhavoronkov
- Biogerontology Research Foundation, London, UK
- Insilico Medicine, Inc., Emerging Technology Centers, Johns Hopkins University, Baltimore, MD, USA
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8
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Lemon JA, Phan N, Boreham DR. Multiple CT Scans Extend Lifespan by Delaying Cancer Progression in Cancer-Prone Mice. Radiat Res 2017; 188:495-504. [DOI: 10.1667/rr14575.1] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Jennifer A. Lemon
- Medical Sciences, Northern Ontario School of Medicine, Sudbury, Canada, P3E 2C6
| | - Nghi Phan
- Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, Canada, L8S 4K1
| | - Douglas R. Boreham
- Medical Sciences, Northern Ontario School of Medicine, Sudbury, Canada, P3E 2C6
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9
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Lemon JA, Phan N, Boreham DR. Single CT Scan Prolongs Survival by Extending Cancer Latency inTrp53Heterozygous Mice. Radiat Res 2017; 188:505-511. [DOI: 10.1667/rr14576.1] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Jennifer A. Lemon
- Medical Sciences Division, Northern Ontario School of Medicine, Sudbury, Canada, P3E 2C6
| | - Nghi Phan
- Department of Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, Canada, L8S 4K1
| | - Douglas R. Boreham
- Medical Sciences Division, Northern Ontario School of Medicine, Sudbury, Canada, P3E 2C6
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10
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Song KH, Jung SY, Kho SH, Hwang SG, Ha H, Nam SY, Song JY. Effects of low-dose irradiation on mice with Escherichia coli-induced sepsis. Toxicol Appl Pharmacol 2017; 333:17-25. [PMID: 28818514 DOI: 10.1016/j.taap.2017.08.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Revised: 08/08/2017] [Accepted: 08/11/2017] [Indexed: 11/19/2022]
Abstract
Although favorable immune responses to low-dose irradiation (LDI) have been observed in normal mice, i.e., a hormesis effect, little is known about the effects of LDI in infectious diseases. In this study, we examined the effects of LDI on mice with sepsis, a severe and often lethal hyperinflammatory response to bacteria. Female C57BL/6 mice were whole-body irradiated with 10cGy 48h before Escherichia coli infection, and survival, bacterial clearance, cytokines, and antioxidants were quantified. LDI pretreatment significantly increased survival from 46.7% in control mice to 75% in mice with sepsis. The bacterial burden was significantly lower in the blood, spleen, and kidney of LDI-treated mice than in those of control septic mice. The levels of pro-inflammatory cytokines, e.g., IL-1β and IL-6, as well as anti-inflammatory IL-10 were markedly reduced in pre-LDI septic mice. Nitric oxide production by peritoneal macrophages was also reduced in pre-LDI septic mice. Immune cells in the spleen increased and Nrf2 and HO-1 were induced in pre-LDI septic mice. LDI stimulates the immune response and minimizes lethality in septic mice via enhanced bacterial clearance and reduced initial proinflammatory responses.
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Affiliation(s)
- Kyung-Hee Song
- Division of Applied Radiation Bioscience, Korea Institute of Radiological & Medical Sciences, 75 Nowon-ro, Nowon-gu, Seoul 01812, Republic of Korea; Graduate School of Pharmaceutical Sciences, College of Pharmacy, Ewha Womans University, 52 Ewhayeodae-gil, Seodaemun-gu, Seoul 03760, Republic of Korea
| | - Seung-Youn Jung
- Division of Applied Radiation Bioscience, Korea Institute of Radiological & Medical Sciences, 75 Nowon-ro, Nowon-gu, Seoul 01812, Republic of Korea
| | - Seong-Ho Kho
- Division of Applied Radiation Bioscience, Korea Institute of Radiological & Medical Sciences, 75 Nowon-ro, Nowon-gu, Seoul 01812, Republic of Korea
| | - Sang-Gu Hwang
- Division of Applied Radiation Bioscience, Korea Institute of Radiological & Medical Sciences, 75 Nowon-ro, Nowon-gu, Seoul 01812, Republic of Korea
| | - Hunjoo Ha
- Graduate School of Pharmaceutical Sciences, College of Pharmacy, Ewha Womans University, 52 Ewhayeodae-gil, Seodaemun-gu, Seoul 03760, Republic of Korea
| | - Seon Young Nam
- Low-Dose Radiation Research Team, Radiation Health Institute, Korea Hydro & Nuclear Power Co., Ltd., Seoul 01450, Republic of Korea
| | - Jie-Young Song
- Division of Applied Radiation Bioscience, Korea Institute of Radiological & Medical Sciences, 75 Nowon-ro, Nowon-gu, Seoul 01812, Republic of Korea.
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11
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Janiak MK, Wincenciak M, Cheda A, Nowosielska EM, Calabrese EJ. Cancer immunotherapy: how low-level ionizing radiation can play a key role. Cancer Immunol Immunother 2017; 66:819-832. [PMID: 28361232 PMCID: PMC5489643 DOI: 10.1007/s00262-017-1993-z] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Accepted: 03/22/2017] [Indexed: 12/17/2022]
Abstract
The cancer immunoediting hypothesis assumes that the immune system guards the host against the incipient cancer, but also "edits" the immunogenicity of surviving neoplastic cells and supports remodeling of tumor microenvironment towards an immunosuppressive and pro-neoplastic state. Local irradiation of tumors during standard radiotherapy, by killing neoplastic cells and generating inflammation, stimulates anti-cancer immunity and/or partially reverses cancer-promoting immunosuppression. These effects are induced by moderate (0.1-2.0 Gy) or high (>2 Gy) doses of ionizing radiation which can also harm normal tissues, impede immune functions, and increase the risk of secondary neoplasms. In contrast, such complications do not occur with exposures to low doses (≤0.1 Gy for acute irradiation or ≤0.1 mGy/min dose rate for chronic exposures) of low-LET ionizing radiation. Furthermore, considerable evidence indicates that such low-level radiation (LLR) exposures retard the development of neoplasms in humans and experimental animals. Here, we review immunosuppressive mechanisms induced by growing tumors as well as immunomodulatory effects of LLR evidently or likely associated with cancer-inhibiting outcomes of such exposures. We also offer suggestions how LLR may restore and/or stimulate effective anti-tumor immunity during the more advanced stages of carcinogenesis. We postulate that, based on epidemiological and experimental data amassed over the last few decades, whole- or half-body irradiations with LLR should be systematically examined for its potential to be a viable immunotherapeutic treatment option for patients with systemic cancer.
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Affiliation(s)
- Marek K Janiak
- Department of Radiobiology and Radiation Protection, Military Institute of Hygiene and Epidemiology, 4 Kozielska St., 01-163, Warsaw, Poland.
| | - Marta Wincenciak
- Department of Radiobiology and Radiation Protection, Military Institute of Hygiene and Epidemiology, 4 Kozielska St., 01-163, Warsaw, Poland
| | - Aneta Cheda
- Department of Radiobiology and Radiation Protection, Military Institute of Hygiene and Epidemiology, 4 Kozielska St., 01-163, Warsaw, Poland
| | - Ewa M Nowosielska
- Department of Radiobiology and Radiation Protection, Military Institute of Hygiene and Epidemiology, 4 Kozielska St., 01-163, Warsaw, Poland
| | - Edward J Calabrese
- Department of Environmental Health Sciences, School of Public Health and Health Sciences, Morrill I, N344, University of Massachusetts, Amherst, MA, 01003, USA
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12
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Morel KL, Ormsby RJ, Bezak E, Sweeney CJ, Sykes PJ. Parthenolide Selectively Sensitizes Prostate Tumor Tissue to Radiotherapy while Protecting Healthy Tissues In Vivo. Radiat Res 2017; 187:501-512. [PMID: 28398879 DOI: 10.1667/rr14710.1] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Radiotherapy is widely used in cancer treatment, however the benefits can be limited by radiation-induced damage to neighboring normal tissues. Parthenolide (PTL) exhibits anti-inflammatory and anti-tumor properties and selectively induces radiosensitivity in prostate cancer cell lines, while protecting primary prostate epithelial cell lines from radiation-induced damage. Low doses of radiation have also been shown to protect from subsequent high-dose-radiation-induced apoptosis as well as DNA damage. These properties of PTL and low-dose radiation could be used to improve radiotherapy by killing more tumor cells and less normal cells. Sixteen-week-old male Transgenic Adenocarcinoma of the Mouse Prostate (TRAMP) and C57BL/6J mice were treated with PTL (40 mg/kg), dimethylaminoparthenolide (DMAPT, a PTL analogue with increased bioavailability) (100 mg/kg), or vehicle control three times over one week prior to combinations of low (10 mGy) and high (6 Gy) doses of whole-body X-irradiation. Tissues were analyzed for apoptosis at a range of time points up to 72 h postirradiation. Both PTL and DMAPT protected normal tissues, but not prostate tumor tissues, from a significant proportion of high-dose-radiation-induced apoptosis. DMAPT provided superior protection compared to PTL in normal dorsolateral prostate (71.7% reduction, P = 0.026), spleen (48.2% reduction, P = 0.0001) and colorectal tissue (38.0% reduction, P = 0.0002), and doubled radiation-induced apoptosis in TRAMP prostate tumor tissue (101.3% increase, P = 0.039). Both drugs induced the greatest radiosensitivity in TRAMP prostate tissue in areas with higher grade prostatic intraepithelial neoplasia (PIN) lesions. A 10 mGy dose delivered 3 h prior to a 6 Gy dose induced a radioadaptive apoptosis response in normal C57Bl/6J prostate (28.4% reduction, P = 0.045) and normal TRAMP spleen (13.6% reduction, P = 0.047), however the low-dose-adaptive radioprotection did not significantly add to the PTL/DMAPT-induced protection in normal tissues, nor did it affect tumor kill. These results support the use of the more bioavailable DMAPT and low-dose radiation, alone or in combination as useful radioprotectors of normal tissues to alleviate radiotherapy-induced side-effects in patients. The enhanced radiosensitisation in prostate tissues displaying high-grade PIN suggests that DMAPT also holds promise for targeted therapy of advanced prostate cancer, which may go on to become metastatic. The redox mechanisms involved in the differential radioprotection observed here suggest that increased radiotherapy efficacy by DMAPT is more broadly applicable to a range of cancer types.
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Affiliation(s)
- Katherine L Morel
- a Molecular Medicine and Pathology, Flinders Centre for Innovation in Cancer, Flinders University and Medical Centre, Bedford Park, Adelaide, South Australia
| | - Rebecca J Ormsby
- a Molecular Medicine and Pathology, Flinders Centre for Innovation in Cancer, Flinders University and Medical Centre, Bedford Park, Adelaide, South Australia
| | - Eva Bezak
- b Medical Radiation, School of Health Sciences, University of South Australia, Adelaide, South Australia
| | | | - Pamela J Sykes
- a Molecular Medicine and Pathology, Flinders Centre for Innovation in Cancer, Flinders University and Medical Centre, Bedford Park, Adelaide, South Australia
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13
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Tang FR, Loke WK, Khoo BC. Low-dose or low-dose-rate ionizing radiation-induced bioeffects in animal models. JOURNAL OF RADIATION RESEARCH 2017; 58:165-182. [PMID: 28077626 PMCID: PMC5439383 DOI: 10.1093/jrr/rrw120] [Citation(s) in RCA: 75] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Revised: 01/22/2016] [Indexed: 05/13/2023]
Abstract
Animal experimental studies indicate that acute or chronic low-dose ionizing radiation (LDIR) (≤100 mSv) or low-dose-rate ionizing radiation (LDRIR) (<6 mSv/h) exposures may be harmful. It induces genetic and epigenetic changes and is associated with a range of physiological disturbances that includes altered immune system, abnormal brain development with resultant cognitive impairment, cataractogenesis, abnormal embryonic development, circulatory diseases, weight gain, premature menopause in female animals, tumorigenesis and shortened lifespan. Paternal or prenatal LDIR/LDRIR exposure is associated with reduced fertility and number of live fetuses, and transgenerational genomic aberrations. On the other hand, in some experimental studies, LDIR/LDRIR exposure has also been reported to bring about beneficial effects such as reduction in tumorigenesis, prolonged lifespan and enhanced fertility. The differences in reported effects of LDIR/LDRIR exposure are dependent on animal genetic background (susceptibility), age (prenatal or postnatal days), sex, nature of radiation exposure (i.e. acute, fractionated or chronic radiation exposure), type of radiation, combination of radiation with other toxic agents (such as smoking, pesticides or other chemical toxins) or animal experimental designs. In this review paper, we aimed to update radiation researchers and radiologists on the current progress achieved in understanding the LDIR/LDRIR-induced bionegative and biopositive effects reported in the various animal models. The roles played by a variety of molecules that are implicated in LDIR/LDRIR-induced health effects will be elaborated. The review will help in future investigations of LDIR/LDRIR-induced health effects by providing clues for designing improved animal research models in order to clarify the current controversial/contradictory findings from existing studies.
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Affiliation(s)
- Feng Ru Tang
- Singapore Nuclear Research and Safety Initiative (SNRSI), National University of Singapore, 1 CREATE Way #04-01, CREATE Tower, 138602, Singapore
| | - Weng Keong Loke
- Temasek Laboratories, National University of Singapore, 5A, Engineering Drive 1, 117411,Singapore
| | - Boo Cheong Khoo
- DSO National Laboratories,Defence Medical and Environmental Research Institute, 11 Stockport Road,117605,Singapore
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14
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Kirschner S, Mürle B, Felix M, Arns A, Groden C, Wenz F, Hug A, Glatting G, Kramer M, Giordano FA, Brockmann MA. Imaging of Orthotopic Glioblastoma Xenografts in Mice Using a Clinical CT Scanner: Comparison with Micro-CT and Histology. PLoS One 2016; 11:e0165994. [PMID: 27829015 PMCID: PMC5102379 DOI: 10.1371/journal.pone.0165994] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Accepted: 10/23/2016] [Indexed: 01/24/2023] Open
Abstract
Purpose There is an increasing need for small animal in vivo imaging in murine orthotopic glioma models. Because dedicated small animal scanners are not available ubiquitously, the applicability of a clinical CT scanner for visualization and measurement of intracerebrally growing glioma xenografts in living mice was validated. Materials and Methods 2.5x106 U87MG cells were orthotopically implanted in NOD/SCID/ᵞc-/- mice (n = 9). Mice underwent contrast-enhanced (300 μl Iomeprol i.v.) imaging using a micro-CT (80 kV, 75 μAs, 360° rotation, 1,000 projections, scan time 33 s, resolution 40 x 40 x 53 μm) and a clinical CT scanner (4-row multislice detector; 120 kV, 150 mAs, slice thickness 0.5 mm, feed rotation 0.5 mm, resolution 98 x 98 x 500 μm). Mice were sacrificed and the brain was worked up histologically. In all modalities tumor volume was measured by two independent readers. Contrast-to-noise ratio (CNR) and Signal-to-noise ratio (SNR) were measured from reconstructed CT-scans (0.5 mm slice thickness; n = 18). Results Tumor volumes (mean±SD mm3) were similar between both CT-modalities (micro-CT: 19.8±19.0, clinical CT: 19.8±18.8; Wilcoxon signed-rank test p = 0.813). Moreover, between reader analyses for each modality showed excellent agreement as demonstrated by correlation analysis (Spearman-Rho >0.9; p<0.01 for all correlations). Histologically measured tumor volumes (11.0±11.2) were significantly smaller due to shrinkage artifacts (p<0.05). CNR and SNR were 2.1±1.0 and 1.1±0.04 for micro-CT and 23.1±24.0 and 1.9±0.7 for the clinical CTscanner, respectively. Conclusion Clinical CT scanners may reliably be used for in vivo imaging and volumetric analysis of brain tumor growth in mice.
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Affiliation(s)
- Stefanie Kirschner
- Department of Neuroradiology, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University, 68167, Mannheim, Germany
| | - Bettina Mürle
- Department of Neuroradiology, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University, 68167, Mannheim, Germany
| | - Manuela Felix
- Medical Radiation Physics/Radiation Protection, Department of Radiation Oncology, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University, 68167, Mannheim, Germany
| | - Anna Arns
- Department of Radiation Oncology, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University, 68167, Mannheim, Germany
| | - Christoph Groden
- Department of Neuroradiology, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University, 68167, Mannheim, Germany
| | - Frederik Wenz
- Department of Radiation Oncology, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University, 68167, Mannheim, Germany
| | - Andreas Hug
- Spinal Cord Injury Center, University Hospital Heidelberg, Schlierbacher Landstr. 200a, 69118, Heidelberg, Germany
| | - Gerhard Glatting
- Medical Radiation Physics/Radiation Protection, Department of Radiation Oncology, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University, 68167, Mannheim, Germany
| | - Martin Kramer
- Department of Veterinary Clinical Sciences, Small Animal Clinic, Justus-Liebig-University, 35392, Giessen, Germany
| | - Frank A. Giordano
- Department of Radiation Oncology, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University, 68167, Mannheim, Germany
| | - Marc A. Brockmann
- Department of Neuroradiology, University Medical Center of the Johannes Gutenberg University Mainz, 55131, Mainz, Germany
- * E-mail:
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15
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Bannister LA, Mantha RR, Devantier Y, Petoukhov ES, Brideau CLA, Serran ML, Klokov DY. Dose and Radioadaptive Response Analysis of Micronucleus Induction in Mouse Bone Marrow. Int J Mol Sci 2016; 17:ijms17091548. [PMID: 27649149 PMCID: PMC5037821 DOI: 10.3390/ijms17091548] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Revised: 09/01/2016] [Accepted: 09/05/2016] [Indexed: 12/12/2022] Open
Abstract
Enhanced cellular DNA repair efficiency and suppression of genomic instability have been proposed as mechanisms underlying radio-adaptive responses following low-dose radiation exposures. We previously showed that low-dose γ irradiation does not generate radio-adaptation by lowering radiation-induced cytogenetic damage in mouse spleen. Since radiation may exert tissue-specific effects, we extended these results here by examining the effects of γ radiation on cytogenetic damage and proliferative index in bone marrow erythrocytes of C57BL/6 and BALB/c mice. In C57BL/6 mice, the induction of micronuclei in polychromatic erythrocytes (MN-PCE) was observed at radiation doses of 100 mGy and greater, and suppression of erythroblast maturation occurred at doses of >500 mGy. A linear dose-response relationship for MN-PCE frequencies in C57BL/6 mice was established for radiation doses between 100 mGy and 1 Gy, with departure from linearity at doses of >1 Gy. BALB/c mice exhibited increased MN-PCE frequencies above baseline following a 20 mGy radiation exposure but did not exhibit radio-sensitivity relative to C57BL/6 mice following 2 Gy exposure. Radio-adaptation of bone marrow erythrocytes was not observed in either strain of mice exposed to low-dose priming γ irradiation (single doses of 20 mGy or 100 mGy or multiple 20 mGy doses) administered at various times prior to acute 2 Gy irradiation, confirming the lack of radio-adaptive response for induction of cytogenetic damage or suppression or erythrocyte proliferation/maturation in bone marrow of these mouse strains.
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Affiliation(s)
- Laura A Bannister
- Canadian Nuclear Laboratories, Radiobiology and Health, Chalk River, ON K0J1J0, Canada.
| | - Rebecca R Mantha
- Canadian Nuclear Laboratories, Radiobiology and Health, Chalk River, ON K0J1J0, Canada.
| | - Yvonne Devantier
- Canadian Nuclear Laboratories, Radiobiology and Health, Chalk River, ON K0J1J0, Canada.
| | - Eugenia S Petoukhov
- Canadian Nuclear Laboratories, Radiobiology and Health, Chalk River, ON K0J1J0, Canada.
| | - Chantal L A Brideau
- Canadian Nuclear Laboratories, Radiobiology and Health, Chalk River, ON K0J1J0, Canada.
| | - Mandy L Serran
- Canadian Nuclear Laboratories, Radiobiology and Health, Chalk River, ON K0J1J0, Canada.
| | - Dmitry Y Klokov
- Canadian Nuclear Laboratories, Radiobiology and Health, Chalk River, ON K0J1J0, Canada.
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16
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Premkumar K, Shankar BS. Involvement of MAPK signalling in radioadaptive response in BALB/c mice exposed to low dose ionizing radiation. Int J Radiat Biol 2016; 92:249-62. [DOI: 10.3109/09553002.2016.1146829] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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17
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Bannister LA, Serran ML, Mantha RR. Low-Dose Gamma Radiation Does Not Induce an Adaptive Response for Micronucleus Induction in Mouse Splenocytes. Radiat Res 2015; 184:533-44. [DOI: 10.1667/rr14102.1] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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18
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Song KH, Kim MH, Kang SM, Jung SY, Ahn J, Woo HJ, Nam SY, Hwang SG, Ryu SY, Song JY. Analysis of immune cell populations and cytokine profiles in murine splenocytes exposed to whole-body low-dose irradiation. Int J Radiat Biol 2015; 91:795-803. [PMID: 26136089 DOI: 10.3109/09553002.2015.1068461] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
PURPOSE In contrast to high-dose therapeutic irradiation, definitive research detailing the physiological effects of low-dose irradiation is limited. Notably, the immunological response elicited after low-dose irradiation remains controversial. MATERIALS AND METHODS Female C57BL/6 mice were whole- body-irradiated with a single or three daily fractions up to a total dose of 0.1, 1, or 10 cGy. Blood and spleen were harvested 2, 7 and 14 days after irradiation. RESULTS The splenic CD4(+) T cell subpopulations were temporarily increased at 2 days after single or fractionated irradiation, whereas the percentage of dendritic cells (DC) and macrophages was decreased. Whereas CD8(+) T cell populations were decreased in single-dose irradiated mice at day 7, early and sustained reduction of CD8(+) T cell numbers was observed in fractionated- dose-irradiated mice from day 2 until day 14. In addition, single-dose irradiation resulted in a Th1 cytokine expression profile, whereas fractionated-dose irradiation drove a Th2 shift. Additionally, increased expression of immune-related factors was observed at early time-points with single-dose irradiation, in contrast to the dose-independent induction following fractionated-dose irradiation. CONCLUSIONS Our results demonstrate that low-dose irradiation modulates the immune response in mice, where the sensitivity and kinetics of the induced response vary according to the dosing method.
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Affiliation(s)
- Kyung-Hee Song
- a Division of Radiation Cancer Research, Korea Institute of Radiological & Medical Sciences , Seoul , Republic of Korea
| | - Mi-Hyoung Kim
- a Division of Radiation Cancer Research, Korea Institute of Radiological & Medical Sciences , Seoul , Republic of Korea.,b Laboratory of Immunology, College of Veterinary Medicine, Seoul National University , Seoul , Republic of Korea
| | - Seong-Mook Kang
- a Division of Radiation Cancer Research, Korea Institute of Radiological & Medical Sciences , Seoul , Republic of Korea
| | - Seung-Youn Jung
- a Division of Radiation Cancer Research, Korea Institute of Radiological & Medical Sciences , Seoul , Republic of Korea
| | - Jiyeon Ahn
- a Division of Radiation Cancer Research, Korea Institute of Radiological & Medical Sciences , Seoul , Republic of Korea
| | - Hee-Jong Woo
- b Laboratory of Immunology, College of Veterinary Medicine, Seoul National University , Seoul , Republic of Korea
| | - Seon Young Nam
- c Radiation Effect Research Team, Radiation Health Research Institute, Korea Hydro & Nuclear Power Co., Ltd , Seoul , Republic of Korea
| | - Sang-Gu Hwang
- a Division of Radiation Cancer Research, Korea Institute of Radiological & Medical Sciences , Seoul , Republic of Korea
| | - Sang-Young Ryu
- d Department of Obstetrics and Gynecology , Korea Cancer Center Hospital, Korea Institute of Radiological & Medical Sciences , Seoul , Republic of Korea
| | - Jie-Young Song
- a Division of Radiation Cancer Research, Korea Institute of Radiological & Medical Sciences , Seoul , Republic of Korea
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19
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Lacoste-Collin L, Jozan S, Pereda V, Courtade-Saïdi M. Influence of A Continuous Very Low Dose of Gamma-Rays on Cell Proliferation, Apoptosis and Oxidative Stress. Dose Response 2015; 13:10.2203_dose-response.14-010.Lacoste-Collin. [PMID: 26692019 PMCID: PMC4679219 DOI: 10.2203/dose-response.14-010.lacoste-collin] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
We have previously shown a delay of death by lymphoma in SJL/J mice irradiated with continuous very low doses of ionizing radiation. In order to understand the mechanisms involved in this phenomenon, we have irradiated in vitro the Raw264.7 monocytic and the YAC-1 lymphoma cell lines at very low-dose rate of 4cGy.month(-1). We have observed a transient increase in production of both free radicals and nitric oxide with a transient adaptive response during at least two weeks after the beginning of the irradiation. The slight decrease of Ki67 proliferation index observed during the second and third weeks of YAC-1 cells culture under irradiation was not significant but consistent with the shift of the proliferation assay curves of YAC-1cells at these same durations of culture. These in vitro results were in good agreement with the slightly decrease under irradiation of Ki67 proliferative index evaluated on lymphomatous lymph nodes of SJL/J mice. A significant decrease of YAC-1 cells apoptotic rate under radiation appeared after 4 weeks of culture. Therefore very small doses of gamma-irradiation are able to modify the cellular response. The main observations did not last with increasing time under irradiation, suggesting a transient adaptation of cells or organisms to this level of irradiation.
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Affiliation(s)
| | - Suzanne Jozan
- Laboratoire d'Histologie-Embryologie, Faculté de Médecine Rangueil, Toulouse, France
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20
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Nenoi M, Wang B, Vares G. In vivo radioadaptive response: a review of studies relevant to radiation-induced cancer risk. Hum Exp Toxicol 2015; 34:272-83. [PMID: 24925363 PMCID: PMC4442823 DOI: 10.1177/0960327114537537] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Radioadaptive response (RAR) describes phenomena where small conditioning doses of ionizing radiation (IR) reduce detrimental effects of subsequent higher IR doses. Current radiation protection regulations do not include RAR because of the large variability in expression among individuals and uncertainties of the mechanism. However, RAR should be regarded as an indispensable factor for estimation and control of individual IR sensitivity. In this article, RAR studies relevant to individual cancer risk are reviewed. Using various stains of mice, carcinogenic RAR has been demonstrated. Consistently much in vivo evidence for RAR with end points of DNA and chromosome damage is reported. Most in vivo RAR studies revealed efficient induction of RAR by chronic or repeated low-dose priming irradiation. Chronic IR-induced RAR was observed also in human individuals after environmental, occupational, and nuclear accident radiation exposure. These observations may be associated with an intrinsically distinct feature of in vivo experimental systems that mainly consist of nonproliferating mature cells. Alternatively, induction of RAR by gap junction-mediated bystander effects suggests that multicellular systems comprising densely communicating cells may be capable of responding to long-lasting low-dose-rate priming irradiation. Regulation by endocrine factors is also a plausible mechanism for RAR at an individual level. Emerging evidence suggests that glucocorticoids, known as stress hormones, participate in in vivo RAR induction following long-term low-dose-rate exposure to IR.
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Affiliation(s)
- M Nenoi
- Research Center for Radiation Protection, National Institute of Radiological Sciences, Inage-ku, Chiba, Japan
| | - B Wang
- Research Center for Radiation Protection, National Institute of Radiological Sciences, Inage-ku, Chiba, Japan
| | - G Vares
- Research Center for Radiation Protection, National Institute of Radiological Sciences, Inage-ku, Chiba, Japan
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21
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Radiation-hormesis phenotypes, the related mechanisms and implications for disease prevention and therapy. J Cell Commun Signal 2014; 8:341-52. [PMID: 25324149 DOI: 10.1007/s12079-014-0250-x] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2014] [Accepted: 10/08/2014] [Indexed: 01/20/2023] Open
Abstract
Humans are continuously exposed to ionizing radiation throughout life from natural sources that include cosmic, solar, and terrestrial. Much harsher natural radiation and chemical environments existed during our planet's early years. Mammals survived the harsher environments via evolutionarily-conserved gifts ̶ a continuously evolving system of stress-induced natural protective measures (i.e., activated natural protection [ANP]). The current protective system is differentially activated by stochastic (i.e., variable) low-radiation-dose thresholds and when optimally activated in mammals includes antioxidants, DNA damage repair, p53-related apoptosis of severely-damaged cells, reactive-oxygen-species (ROS)/reactive-nitrogen-species (RNS)- and cytokine-regulated auxiliary apoptosis that selectively removes aberrant cells (e.g., precancerous cells), suppression of disease promoting inflammation, and immunity against cancer cells. The intercellular-signaling-based protective system is regulated at least in part via epigenetic reprogramming of adaptive-response genes. When the system is optimally activated, it protects against cancer and some other diseases, thereby leading to hormetic phenotypes (e.g., reduced disease incidence to below the baseline level; reduced pain from inflammation-related problems). Here, some expressed radiation hormesis phenotypes and related mechanisms are discussed along with their implications for disease prevention and therapy.
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22
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Tang FR, Loke WK. Molecular mechanisms of low dose ionizing radiation-induced hormesis, adaptive responses, radioresistance, bystander effects, and genomic instability. Int J Radiat Biol 2014; 91:13-27. [DOI: 10.3109/09553002.2014.937510] [Citation(s) in RCA: 87] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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23
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van der Linden JC, Waarsing JH, Weinans H. The use of micro-CT to study bone architecture dynamics noninvasively. DRUG DISCOVERY TODAY. TECHNOLOGIES 2014; 3:213-9. [PMID: 24980410 DOI: 10.1016/j.ddtec.2006.06.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
High-resolution micro-CT has become a standard tool in the evaluation of bone architecture. It has recently progressed from an invasive tool for bone specimens into an in vivo tool for small animals. The combination of novel sophisticated evaluation methods, such as registration (matching) of sequential scans and computer simulation models will further evolve in vivo micro-CT into an optimal tool for small animal phenotyping and contemporary approaches for drug discovery relating to the skeleton.:
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Affiliation(s)
| | - Jan H Waarsing
- Department Orthopaedics, Erasmus MC, Rotterdam, The Netherlands
| | - Harrie Weinans
- Department Orthopaedics, Erasmus MC, Rotterdam, The Netherlands.
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Lemon JA, Taylor K, Verdecchia K, Phan N, Boreham DR. The influence of Trp53 in the dose response of radiation-induced apoptosis, DNA repair and genomic stability in murine haematopoietic cells. Dose Response 2014; 12:365-85. [PMID: 25249831 PMCID: PMC4146330 DOI: 10.2203/dose-response.14-008.lemon] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Apoptotic and DNA damage endpoints are frequently used as surrogate markers of cancer risk, and have been well-studied in the Trp53+/- mouse model. We report the effect of differing Trp53 gene status on the dose response of ionizing radiation exposures (0.01-2 Gy), with the unique perspective of determining if effects of gene status remain at extended time points. Here we report no difference in the dose response for radiation-induced DNA double-strand breaks in bone marrow and genomic instability (MN-RET levels) in peripheral blood, between wild-type (Trp53+/+) and heterozygous (Trp53+/-) mice. The dose response for Trp53+/+ mice showed higher initial levels of radiation-induced lymphocyte apoptosis relative to Trp53+/- between 0 and 1 Gy. Although this trend was observed up to 12 hours post-irradiation, both genotypes ultimately reached the same level of apoptosis at 14 hours, suggesting the importance of late-onset p53-independent apoptotic responses in this mouse model. Expected radiation-induced G1 cell cycle delay was observed in Trp53+/+ but not Trp53+/-. Although p53 has an important role in cancer risk, we have shown its influence on radiation dose response can be temporally variable. This research highlights the importance of caution when using haematopoietic endpoints as surrogates to extrapolate radiation-induced cancer risk estimation.
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Affiliation(s)
- Jennifer A. Lemon
- McMaster University, Department of Medical Physics and Applied Radiation Sciences, Hamilton, ON L8S 4K1
| | - Kristina Taylor
- McMaster University, Department of Medical Physics and Applied Radiation Sciences, Hamilton, ON L8S 4K1
| | - Kyle Verdecchia
- McMaster University, Department of Medical Physics and Applied Radiation Sciences, Hamilton, ON L8S 4K1
| | - Nghi Phan
- McMaster University, Department of Medical Physics and Applied Radiation Sciences, Hamilton, ON L8S 4K1
| | - Douglas R. Boreham
- McMaster University, Department of Medical Physics and Applied Radiation Sciences, Hamilton, ON L8S 4K1
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Shimura N. Effects of low-dose-gamma rays on the immune system of different animal models of disease. Dose Response 2014; 12:429-65. [PMID: 25249835 PMCID: PMC4146334 DOI: 10.2203/dose-response.13-042.shimura] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
We reviewed the beneficial or harmful effects of low-dose ionizing radiation on several diseases based on a search of the literature. The attenuation of autoimmune manifestations in animal disease models irradiated with low-dose γ-rays was previously reported by several research groups, whereas the exacerbation of allergic manifestations was described by others. Based on a detailed examination of the literature, we divided animal disease models into two groups: one group consisting of collagen-induced arthritis (CIA), experimental encephalomyelitis (EAE), and systemic lupus erythematosus, the pathologies of which were attenuated by low-dose irradiation, and another group consisting of atopic dermatitis, asthma, and Hashimoto's thyroiditis, the pathologies of which were exacerbated by low-dose irradiation. The same biological indicators, such as cytokine levels and T-cell subpopulations, were examined in these studies. Low-dose irradiation reduced inter-feron (IFN)-gamma (γ) and interleukin (IL)-6 levels and increased IL-5 levels and the percentage of CD4(+)CD25(+)Foxp3(+)Treg cells in almost all immunological disease cases examined. Variations in these biological indicators were attributed to the attenuation or exacerbation of the disease's manifestation. We concluded that autoimmune diseases caused by autoantibodies were attenuated by low-dose irradiation, whereas diseases caused by antibodies against external antigens, such as atopic dermatitis, were exacerbated.
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Affiliation(s)
- Noriko Shimura
- Faculty of Pharmaceutical Sciences, Ohu University, Japan
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26
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Taylor K, Lemon JA, Phan N, Boreham DR. Low-dose radiation from 18F-FDG PET does not increase cancer frequency or shorten latency but reduces kidney disease in cancer-prone Trp53+/- mice. Mutagenesis 2014; 29:289-94. [PMID: 24870563 DOI: 10.1093/mutage/geu017] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
There is considerable interest in the health effects associated with low-level radiation exposure from medical imaging procedures. Concerns in the medical community that increased radiation exposure from imaging procedures may increase cancer risk among patients are confounded by research showing that low-dose radiation exposure can extend lifespan by increasing the latency period of some types of cancer. The most commonly used radiopharmaceutical for positron emission tomography (PET) scans is 2-[(18)F] fluoro-2-deoxy-d-glucose ((18)F-FDG), which exposes tissue to a low-dose, mixed radiation quality: 634 keV β+ and 511 keV γ-rays. The goal of this research was to investigate how modification of cancer risk associated with exposure to low-dose ionising radiation in cancer-prone Trp53+/- mice is influenced by radiation quality from PET. At 7-8 weeks of age, Trp53+/- female mice were exposed to one of five treatments: 0 Gy, 10 mGy γ-rays, 10 mGy (18)F-FDG, 4 Gy γ-rays, 10 mGy (18)F-FDG + 4 Gy γ-rays (n > 185 per group). The large 4-Gy radiation dose significantly reduced the lifespan by shortening the latency period of cancer and significantly increasing the number of mice with malignancies, compared with unirradiated controls. The 10 mGy γ-rays and 10 mGy PET doses did not significantly modify the frequency or latency period of cancer relative to unirradiated mice. Similarly, the PET scan administered prior to a large 4-Gy dose did not significantly modify the latency or frequency of cancer relative to mice receiving a dose of only 4 Gy. The relative biological effectiveness of radiation quality from (18)F-FDG, with respect to malignancy, is approximately 1. However; when non-cancer endpoints were studied, it was found that the 10-mGy PET group had a significant reduction in kidney lesions (P < 0.021), indicating that a higher absorbed dose (20 ± 0.13 mGy), relative to the whole-body average, which occurs in specific tissues, may not be detrimental.
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Affiliation(s)
- Kristina Taylor
- Department of Medical Physics and Applied Radiation Sciences, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4K1, Canada and Department of Nuclear Medicine, McMaster University Medical Centre, 1200 Main Street West, Hamilton, Ontario L8N 3Z5, Canada
| | - Jennifer A Lemon
- Department of Medical Physics and Applied Radiation Sciences, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4K1, Canada and
| | - Nghi Phan
- Department of Medical Physics and Applied Radiation Sciences, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4K1, Canada and
| | - Douglas R Boreham
- Department of Medical Physics and Applied Radiation Sciences, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4K1, Canada and
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Blimkie MSJ, Fung LCW, Petoukhov ES, Girard C, Klokov D. Repair of DNA double-strand breaks is not modulated by low-dose gamma radiation in C57BL/6J mice. Radiat Res 2014; 181:548-59. [PMID: 24785832 DOI: 10.1667/rr13324.1] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
In this study, we sought to determine whether low-dose ionizing radiation, previously shown to induce a systemic adaptive response in C57BL/6J mice, is capable of enhancing the rate of DNA double-strand break repair. Repair capacity was determined by measuring γ-H2AX levels in splenic and thymic lymphocytes, using flow cytometry, at different times after a challenge irradiation (2 Gy, (60)Co). Irradiation with low doses (20 and 100 mGy) was conducted in vivo, whereas the challenge dose was applied to primary cultures of splenocytes and thymocytes in vitro 24 h later. Obtained kinetics curves of formation and loss of γ-H2AX indicated that cells from low-dose irradiated mice did not express more efficient DNA double-strand break repair compared to controls. Immunoblot analysis of γ-H2AX and Phospho-Ser-1981 ATM confirmed that DNA damage signaling was not modulated by preliminary low-dose radiation. Mouse embryonic fibroblasts of C57BL genetic background failed to show clonogenic survival radioadaptive response or enhanced repair of DNA double-strand breaks as evaluated by immunofluorescence microscopy of γ-H2AX foci. Our results indicate that radiation adaptive responses at systemic levels, such as increases in the tumor latency times in aging mice, may not be mediated by modulated DNA repair, and that the genetic background may affect expression of a radioadaptive response.
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Affiliation(s)
- Melinda S J Blimkie
- a Chalk River Laboratories, Atomic Energy of Canada Limited, Chalk River, Ontario, Canada
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28
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Newman MR, Sykes PJ, Blyth BJ, Bezak E, Lawrence MD, Morel KL, Ormsby RJ. A single whole-body low dose X-irradiation does not affect L1, B1 and IAP repeat element DNA methylation longitudinally. PLoS One 2014; 9:e93016. [PMID: 24676381 PMCID: PMC3968115 DOI: 10.1371/journal.pone.0093016] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2013] [Accepted: 02/27/2014] [Indexed: 11/18/2022] Open
Abstract
The low dose radioadaptive response has been shown to be protective against high doses of radiation as well as aging-induced genomic instability. We hypothesised that a single whole-body exposure of low dose radiation would induce a radioadaptive response thereby reducing or abrogating aging-related changes in repeat element DNA methylation in mice. Following sham or 10 mGy X-irradiation, serial peripheral blood sampling was performed and differences in Long Interspersed Nucleic Element 1 (L1), B1 and Intracisternal-A-Particle (IAP) repeat element methylation between samples were assessed using high resolution melt analysis of PCR amplicons. By 420 days post-irradiation, neither radiation- or aging-related changes in the methylation of peripheral blood, spleen or liver L1, B1 and IAP elements were observed. Analysis of the spleen and liver tissues of cohorts of untreated aging mice showed that the 17-19 month age group exhibited higher repeat element methylation than younger or older mice, with no overall decline in methylation detected with age. This is the first temporal analysis of the effect of low dose radiation on repeat element methylation in mouse peripheral blood and the first to examine the long term effect of this dose on repeat element methylation in a radiosensitive tissue (spleen) and a tissue fundamental to the aging process (liver). Our data indicate that the methylation of murine DNA repeat elements can fluctuate with age, but unlike human studies, do not demonstrate an overall aging-related decline. Furthermore, our results indicate that a low dose of ionising radiation does not induce detectable changes to murine repeat element DNA methylation in the tissues and at the time-points examined in this study. This radiation dose is relevant to human diagnostic radiation exposures and suggests that a dose of 10 mGy X-rays, unlike high dose radiation, does not cause significant short or long term changes to repeat element or global DNA methylation.
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Affiliation(s)
- Michelle R. Newman
- Flinders Centre for Innovation in Cancer, Flinders University and Medical Centre, Bedford Park, South Australia, Australia
| | - Pamela J. Sykes
- Flinders Centre for Innovation in Cancer, Flinders University and Medical Centre, Bedford Park, South Australia, Australia
| | - Benjamin J. Blyth
- Flinders Centre for Innovation in Cancer, Flinders University and Medical Centre, Bedford Park, South Australia, Australia
| | - Eva Bezak
- Department of Medical Physics, Royal Adelaide Hospital, Adelaide, South Australia, Australia
| | - Mark D. Lawrence
- Flinders Centre for Innovation in Cancer, Flinders University and Medical Centre, Bedford Park, South Australia, Australia
| | - Katherine L. Morel
- Flinders Centre for Innovation in Cancer, Flinders University and Medical Centre, Bedford Park, South Australia, Australia
| | - Rebecca J. Ormsby
- Flinders Centre for Innovation in Cancer, Flinders University and Medical Centre, Bedford Park, South Australia, Australia
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29
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Shu M, Kuo S, Wang Y, Jiang Y, Liu YT, Gallo RL, Huang CM. Porphyrin metabolisms in human skin commensal Propionibacterium acnes bacteria: potential application to monitor human radiation risk. Curr Med Chem 2014; 20:562-8. [PMID: 23231351 DOI: 10.2174/0929867311320040007] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2012] [Revised: 12/06/2012] [Accepted: 12/06/2012] [Indexed: 11/22/2022]
Abstract
Propionibacterium acnes (P. acnes), a Gram-positive anaerobic bacterium, is a commensal organism in human skin. Like human cells, the bacteria produce porphyrins, which exhibit fluorescence properties and make bacteria visible with a Wood's lamp. In this review, we compare the porphyrin biosynthesis in humans and P. acnes. Also, since P. acnes living on the surface of skin receive the same radiation exposure as humans, we envision that the changes in porphyrin profiles (the absorption spectra and/or metabolism) of P. acnes by radiation may mirror the response of human cells to radiation. The porphyrin profiles of P. acnes may be a more accurate reflection of radiation risk to the patient than other biodosimeters/biomarkers such as gene up-/down-regulation, which may be non-specific due to patient related factors such as autoimmune diseases. Lastly, we discuss the challenges and possible solutions for using the P. acnes response to predict the radiation risk.
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Affiliation(s)
- M Shu
- Division of Dermatology, Department of Medicine, University of California, San Diego, CA 92121, USA
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30
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Lawrence MD, Ormsby RJ, Blyth BJ, Bezak E, England G, Newman MR, Tilley WD, Sykes PJ. Lack of high-dose radiation mediated prostate cancer promotion and low-dose radiation adaptive response in the TRAMP mouse model. Radiat Res 2013; 180:376-88. [PMID: 23971516 DOI: 10.1667/rr3381.2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Cancer of the prostate is a highly prevalent disease with a heterogeneous aetiology and prognosis. Current understanding of the biological mechanisms underlying the responses of prostate tissue to ionizing radiation exposure, including cancer induction, is surprisingly limited for both high- and low-dose exposures. As population exposure to radiation increases, largely through medical imaging, a better understanding of the response of the prostate to radiation exposure is required. Low-dose radiation-induced adaptive responses for increased cancer latency and decreased cancer frequency have been demonstrated in mouse models, largely for hematological cancers. This study examines the effects of high- and low-dose whole-body radiation exposure on prostate cancer development using an autochthonous mouse model of prostate cancer: TRansgenic Adenocarcinoma of the Mouse Prostate (TRAMP). TRAMP mice were exposed to single acute high (2 Gy), low (50 mGy) and repeated low (5 × 50 mGy) doses of X rays to evaluate both the potential prostate cancer promoting effects of high-dose radiation and low-dose adaptive response phenomena in this prostate cancer model. Prostate weights and histopathology were examined to evaluate gross changes in cancer development and, in mice exposed to a single 2 Gy dose, time to palpable tumor was examined. Proliferation (Ki-67), apoptosis, DNA damage (γ-H2AX) and transgene expression (large T-antigen) were examined within TRAMP prostate sections. Neither high- nor low-dose radiation-induced effects on prostate cancer progression were observed for any of the endpoints studied. Lack of observable effects of high- or low-dose radiation exposure suggests that modulation of tumorigenesis in the TRAMP model is largely resistant to such exposures. However, further study is required to better assess the effects of radiation exposure using alternative prostate cancer models that incorporate normal prostate and in those that are not driven by SV40 large T antigen.
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Affiliation(s)
- M D Lawrence
- a Haematology & Genetic Pathology, Flinders Centre for Innovation in Cancer, Flinders University and Medical Centre, Bedford Park, Adelaide, South Australia, Australia
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31
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Abstract
TP53’s role as guardian of the genome diminishes with age, as the probability of mutation increases. Previous studies have shown an association between p53 gene mutations and cancer. However, the role of somatic TP53 mutations in the steep rise in cancer rates with aging has not been investigated at a population level. This relationship was quantified using the International Agency for Research on Cancer (IARC) TP53 and GLOBOCAN cancer databases. The power function exponent of the cancer rate was calculated for 5-y age-standardized incidence or mortality rates for up to 25 cancer sites occurring in adults of median age 42 to 72 y. Linear regression analysis of the mean percentage of a cancer’s TP53 mutations and the corresponding cancer exponent was conducted for four populations: worldwide, Japan, Western Europe, and the United States. Significant associations (P ≤ 0.05) were found for incidence rates but not mortality rates. Regardless of the population studied, positive associations were found for all cancer sites, with more significant associations for solid tumors, excluding the outlier prostate cancer or sex-related tumors. Worldwide and Japanese populations yielded P values as low as 0.002 and 0.005, respectively. For the United States, a significant association was apparent only when analysis utilized the Surveillance, Epidemiology, and End Results (SEER) database. This study found that TP53 mutations accounts for approximately one-quarter and one-third of the aging-related rise in the worldwide and Japanese incidence of all cancers, respectively. These significant associations between TP53 mutations and the rapid rise in cancer incidence with aging, considered with previously published literature, support a causal role for TP53 according to the Bradford-Hill criteria. However, questions remain concerning the contribution of TP53 mutations to neoplastic development and the role of factors such as genetic instability, obesity, and gene deficiencies other than TP53 that reduce p53 activity.
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Affiliation(s)
- Richard B Richardson
- Radiological Protection Research and Instrumentation Branch; Atomic Energy of Canada Limited; Chalk River Laboratories; Chalk River, ON Canada
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32
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In vivo γ-irradiation low dose threshold for suppression of DNA double strand breaks below the spontaneous level in mouse blood and spleen cells. Mutat Res 2013; 756:141-5. [PMID: 23664857 DOI: 10.1016/j.mrgentox.2013.04.016] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2013] [Accepted: 04/26/2013] [Indexed: 11/22/2022]
Abstract
There is a considerable controversy as to whether DNA damage induced by low doses and low dose rates of ionizing radiation is treated by cellular defence mechanisms in ways similar to that induced at high doses and high dose rates, and what downstream delayed effects may be caused by low doses compared to moderate and high doses. This constitutes the major challenge for the linear no-threshold model currently used for radiological risk estimates. Among the various DNA lesions induced by ionizing radiation, DNA double strand breaks (DSBs) are considered the most important due to their potential to cause cell death, mutagenesis and carcinogenesis. This study examined the accumulation of DNA DSBs in mouse blood leucocytes and splenocytes after long-term, chronic low dose γ-irradiation in vivo, and how this exposure may alter cell sensitivity to acute high dose irradiation. Animals were irradiated for 40, 80 or 120 days at a dose rate of 0.15mGy/h, with total accumulated doses of 144, 288 and 432mGy. DNA DSBs were measured in blood leucocytes and splenocytes using the neutral comet assay. We found that after an initial slight increase in the level of DNA DSBs at 40 days of exposure compared to controls, there was a subsequent drop after either 80 (P<0.01) or 120 days of exposure (P=0.066 for blood leucocytes; P=0.024 for splenocytes). Interestingly, the DNA breaks level after both 80 and 120 days of exposure was lower than in control. Similarly, the cells exposed to the chronic radiation for 80 and 120 days were less sensitive to the induction of DNA DSBs by acute 4Gy irradiation, whereas 40 days of exposure did not significantly modify the radiosensitivity. Our results indirectly indicate that low level ionizing radiation in vivo may trigger inducible repair of both endogenous and exogenous DNA DSBs, and that there is a dose threshold for this inducible defence mechanism, below which it does not occur. These data provide new evidence, now at the molecular level in vivo, that the dose-response for DNA DSBs at very low doses and dose rates is not linear.
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Morgan WF, Bair WJ. Issues in Low Dose Radiation Biology: The Controversy Continues. A Perspective. Radiat Res 2013; 179:501-10. [DOI: 10.1667/rr3306.1] [Citation(s) in RCA: 102] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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34
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Park HS, Seong KM, Kim JY, Kim CS, Yang KH, Jin YW, Nam SY. Chronic low-dose radiation inhibits the cells death by cytotoxic high-dose radiation increasing the level of AKT and acinus proteins via NF-κB activation. Int J Radiat Biol 2013. [DOI: 10.3109/09553002.2013.754560] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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35
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Mitchel REJ, Hasu M, Bugden M, Wyatt H, Hildebrandt G, Chen YX, Priest ND, Whitman SC. Low-dose radiation exposure and protection against atherosclerosis in ApoE(-/-) mice: the influence of P53 heterozygosity. Radiat Res 2013; 179:190-9. [PMID: 23289388 DOI: 10.1667/rr3140.1] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
We recently described the effects of low-dose γ-radiation exposures on atherosclerosis in genetically susceptible (ApoE(-/-)) mice with normal p53 function. Doses as low as 25 mGy, given at either early or late stage disease, generally protected against atherosclerosis in a manner distinctly nonlinear with dose. We now report the influence of low doses (25-500 mGy) on atherosclerosis in ApoE(-/-) mice with reduced p53 function (Trp53(+/-)). Single exposures were given at either low or high dose rate (1 or 150 mGy/min) to female C57BL/6J ApoE(-/-) Trp53(+/-) mice. Mice were exposed at either early stage disease (2 months of age) and examined 3 or 6 months later, or at late stage disease (7 months of age) and examined 2 or 4 months later. In unirradiated mice, reduced p53 functionality elevated serum cholesterol and accelerated both aortic root lesion growth and severity in young mice. Radiation exposure to doses as low as 25 mGy at early stage disease, at either the high or the low dose rate, inhibited lesion growth, decreased lesion frequency and slowed the progression of lesion severity in the aortic root. In contrast, exposure at late stage disease produced generally detrimental effects. Both low-and high-dose-rate exposures accelerated lesion growth and high dose rate exposures also increased serum cholesterol levels. These results show that at early stage disease, reduced p53 function does not influence the protective effects against atherosclerosis of low doses given at low dose rate. In contrast, when exposed to the same doses at late stage disease, reduced p53 function produced detrimental effects, rather than the protective effects seen in Trp53 normal mice. As in the Trp53 normal mice, all effects were highly nonlinear with dose. These results indicate that variations in p53 functionality can dramatically alter the outcome of a low-dose exposure, and that the assumption of a linear response with dose for human populations is probably unwarranted.
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Affiliation(s)
- R E J Mitchel
- Radiological Protection Research and Instrumentation Branch, Atomic Energy of Canada Limited, Chalk River, Ontario, Canada.
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36
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Nowosielska EM, Cheda A, Wrembel-Wargocka J, Janiak MK. Effect of low doses of low-let radiation on the innate anti-tumor reactions in radioresistant and radiosensitive mice. Dose Response 2012; 10:500-15. [PMID: 23304101 PMCID: PMC3526324 DOI: 10.2203/dose-response.12-018.nowosielska] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
BALB/c and C57BL/6 mice differ in their Th1/Th2 lymphocyte and M1/M2 macrophage phenotypes, radiosensitivity, and post-irradiation tumor incidence. In this study we evaluated the effects of repeated low-level exposures to X-rays on the development of artificial tumor colonies in the lungs of animals from the two strains and cytotoxic activities of natural killer (NK) cells and macrophages obtained from these mice. After ten daily irradiations of BALB/c or C57BL/6 mice with 0.01, 0.02, and 0.1 Gy X-rays NK cell-enriched splenocytes collected from the animals demonstrated significant and comparable up-regulation of their anti-tumor cytotoxic function. Likewise, peritoneal macrophages collected from the two irradiated strains of mice exhibited the similarly stimulated cytotoxicities against susceptible tumor cells and produced significantly more nitric oxide. These results were accompanied by the significantly reduced numbers of the neoplastic colonies induced in the lungs by intravenous injection of syngeneic tumor cells. The obtained results indicate that ten low-level irradiations with X-rays stimulate the generally similar anti-tumor reactions in BALB/c and C57BL/6 mice.
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Affiliation(s)
- Ewa M. Nowosielska
- Department of Radiobiology and Radiation Protection, Military Institute of Hygiene and Epidemiology, 4 Kozielska St., 01-163 Warsaw, Poland
| | - Aneta Cheda
- Department of Radiobiology and Radiation Protection, Military Institute of Hygiene and Epidemiology, 4 Kozielska St., 01-163 Warsaw, Poland
| | - Jolanta Wrembel-Wargocka
- Department of Radiobiology and Radiation Protection, Military Institute of Hygiene and Epidemiology, 4 Kozielska St., 01-163 Warsaw, Poland
| | - Marek K. Janiak
- Department of Radiobiology and Radiation Protection, Military Institute of Hygiene and Epidemiology, 4 Kozielska St., 01-163 Warsaw, Poland
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37
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Sanders CL. Potential treatment of inflammatory and proliferative diseases by ultra-low doses of ionizing radiations. Dose Response 2012; 10:610-25. [PMID: 23304108 DOI: 10.2203/dose-response.12-017.sanders] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Ultra-low doses and dose- rates of ionizing radiation are effective in preventing disease which suggests that they also may be effective in treating disease. Limited experimental and anecdotal evidence indicates that low radiation doses from radon in mines and spas, thorium-bearing monazite sands and enhanced radioactive uranium ore obtained from a natural geological reactor may be useful in treating many inflammatory conditions and proliferative disorders, including cancer. Optimal therapeutic applications were identified via a literature survey as dose-rates ranging from 7 to 11μGy/hr or 28 to 44 times world average background rates. Rocks from an abandoned uranium mine in Utah were considered for therapeutic application and were examined by γ-ray and laser-induced breakdown fluorescence spectroscopy. The rocks showed the presence of transuranics and fission products with a γ-ray energy profile similar to aged spent uranium nuclear fuel (93% dose due to β particles and 7% due to γ rays). Mud packs of pulverized uranium ore rock dust in sealed plastic bags delivering bag surface β,γ dose-rates of 10-450 μGy/h were used with apparent success to treat several inflammatory and proliferative conditions in humans.
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Affiliation(s)
- Charles L Sanders
- Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, Daejeon, Korea and 2030 New Hampshire Street, Loveland, CO 80538
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Scott BR, Bruce VR, Gott KM, Wilder J, March T. Small γ-Ray Doses Prevent Rather than Increase Lung Tumors in Mice. Dose Response 2012; 10:527-40. [PMID: 23304103 DOI: 10.2203/dose-response.12-035.scott] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
We show evidence for low doses of γ rays preventing spontaneous hyperplastic foci and adenomas in the lungs of mice, presumably via activating natural anticancer defenses. The evidence partly relates to a new study we conducted whereby a small number of female A/J mice received 6 biweekly dose fractions (100 mGy per fraction) of γ rays to the total body which prevented the occurrence of spontaneous hyperplastic foci in the lung. We also analyzed data from a much earlier Oak Ridge National Laboratory study involving more than 10,000 female RFMf/Un mice whereby single γ-ray doses from 100 to 1,000 mGy prevented spontaneous lung adenomas. We point out the possibility that the decrease in lung cancer mortality observed in The National Lung Screening Trial Research Team study involving lung tumor screening using low-dose computed tomography (CT) may relate at least in part to low-dose X-rays activating the body's natural anticancer defenses (i.e., radiation hormesis). This possibility was apparently not recognized by the indicated research team.
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Affiliation(s)
- B R Scott
- Lovelace Respiratory Research Institute, 2425 Ridgecrest Drive SE, Albuquerque, NM 87108
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Abstract
Aberrations in the p53 tumor suppressor pathway are associated with hematologic malignancies. p53-dependent cell cycle control, senescence, and apoptosis functions are actively involved in maintaining hematopoietic homeostasis under normal and stress conditions. Whereas loss of p53 function promotes leukemia and lymphoma development in humans and mice, increased p53 activity inhibits hematopoietic stem cell function and results in myelodysplasia. Thus, exquisite regulation of p53 activity is critical for homeostasis. Most of our understanding of p53 function in hematopoiesis is derived from genetically engineered mice. Here we summarize some of these models, the various mechanisms that disrupt the regulation of p53 activity, and their relevance to human disease.
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40
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Manda K, Glasow A, Paape D, Hildebrandt G. Effects of ionizing radiation on the immune system with special emphasis on the interaction of dendritic and T cells. Front Oncol 2012; 2:102. [PMID: 22937525 PMCID: PMC3426842 DOI: 10.3389/fonc.2012.00102] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2012] [Accepted: 07/31/2012] [Indexed: 01/01/2023] Open
Abstract
Dendritic cells (DCs), as professional antigen-presenting cells, are members of the innate immune system and function as key players during the induction phase of adaptive immune responses. Uptake, processing, and presentation of antigens direct the outcome toward either tolerance or immunity. The cells of the immune system are among the most highly radiosensitive cells in the body. For high doses of ionizing radiation (HD-IR) both immune-suppressive effects after whole body irradiation and possible immune activation during tumor therapy were observed. On the other hand, the effects of low doses of ionizing radiation (LD-IR) on the immune system are controversial and seem to show high variability among different individuals and species. There are reports revealing that protracted LD-IR can result in radioresistance. But immune-suppressive effects of chronic LD-IR are also reported, including the killing or sensitizing of certain cell types. This article shall review the current knowledge of radiation-induced effects on the immune system, paying special attention to the interaction of DCs and T cells.
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Affiliation(s)
- Katrin Manda
- Department of Radiotherapy and Radiation Oncology, University of Rostock Rostock, Germany
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41
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Mozdarani H. Biological complexities in radiation carcinogenesis and cancer radiotherapy: impact of new biological paradigms. Genes (Basel) 2012; 3:90-114. [PMID: 24704845 PMCID: PMC3899963 DOI: 10.3390/genes3010090] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2011] [Revised: 01/07/2012] [Accepted: 01/13/2012] [Indexed: 12/31/2022] Open
Abstract
Although radiation carcinogenesis has been shown both experimentally and epidemiologically, the use of ionizing radiation is also one of the major modalities in cancer treatment. Various known cellular and molecular events are involved in carcinogenesis. Apart from the known phenomena, there could be implications for carcinogenesis and cancer prevention due to other biological processes such as the bystander effect, the abscopal effect, intrinsic radiosensitivity and radioadaptation. Bystander effects have consequences for mutation initiated cancer paradigms of radiation carcinogenesis, which provide the mechanistic justification for low-dose risk estimates. The abscopal effect is potentially important for tumor control and is mediated through cytokines and/or the immune system (mainly cell-mediated immunity). It results from loss of growth and stimulatory and/or immunosuppressive factors from the tumor. Intrinsic radiosensitivity is a feature of some cancer prone chromosomal breakage syndromes such as ataxia telangectiasia. Radiosensitivity is manifested as higher chromosomal aberrations and DNA repair impairment is now known as a good biomarker for breast cancer screening and prediction of prognosis. However, it is not yet known whether this effect is good or bad for those receiving radiation or radiomimetic agents for treatment. Radiation hormesis is another major concern for carcinogenesis. This process which protects cells from higher doses of radiation or radio mimic chemicals, may lead to the escape of cells from mitotic death or apoptosis and put cells with a lower amount of damage into the process of cancer induction. Therefore, any of these biological phenomena could have impact on another process giving rise to genome instability of cells which are not in the field of radiation but still receiving a lower amount of radiation. For prevention of radiation induced carcinogenesis or risk assessment as well as for successful radiation therapy, all these phenomena should be taken into account.
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Affiliation(s)
- Hossein Mozdarani
- Department of Medical Genetics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran P.O. Box 14115-111, Iran.
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Abstract
Today's radiation safety norms are based on the linear no-threshold theory (LNT): extrapolation of the dose-response relationships down to the minimal doses, where such relationships are unproven and can be inverse due to hormesis. The most promising way to obtaining reliable data on the dose-effect relationships for low radiation doses would be large-scale animal experiments. Outstanding published data on carcinogenic effects of the doses e.g. below 100 mSv should be verified by experiments. Arguments against applicability of the LNT to the doses comparable to those from the natural radiation background are discussed. Furthermore it is stressed that medical consequences of the Chernobyl accident have been overestimated; and this theme has been exploited to strangle development of atomic energy and to elevate prices for fossil fuels. Worldwide introduction of nuclear energy will be possible only after a concentration of authority within a powerful international executive. It would enable the construction of nuclear reactors in optimally suitable places, considering all sociopolitical, geographical, and geological conditions, which would contribute to the prevention of accidents like in Japan in 2011. A concluding point is that radiation safety norms are exceedingly restrictive and should be revised to become more realistic and workable. Elevation of the limits must be accompanied by measures guaranteeing their strict observance. It is also concluded that there are no evidence-based contraindications to fivefold elevation of the total equivalent effective doses to individual members of the public (up to 5 mSv/year), and doubling of the limits for professional exposures.
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Affiliation(s)
- SV Jargin
- Peoples’ Friendship University of Russia, Moscow, Russian Federation
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43
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Rithidech KN, Lai X, Honikel L, Reungpatthanaphong P, Witzmann FA. Identification of proteins secreted into the medium by human lymphocytes irradiated in vitro with or without adaptive environments. HEALTH PHYSICS 2012; 102:39-53. [PMID: 22134077 PMCID: PMC3744879 DOI: 10.1097/hp.0b013e31822833af] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
There is increasing evidence to support the hypothesis of adaptive response, a phenomenon in which protection arises from a low-dose radiation (<0.1 Gy) against damage induced by subsequent exposure to high-dose radiation. The molecular mechanisms underlying such protection are poorly understood. The goal of this study was to fill this knowledge gap. Mass spectrometry-based proteomics was used to characterize global protein expression profiles in the medium collected from human lymphocyte cultures given sham irradiation (0 Gy) or a priming low dose of 0.03 Gy 137Cs γ rays 4 h prior to a challenging dose of 1 Gy 137Cs γ rays. Adaptive response was determined by decreased micronucleus frequencies in lymphocytes receiving low dose irradiation prior to high dose irradiation compared to those receiving only high dose irradiation. Adaptive response was found in these experiments. Proteomic analysis of media revealed: (a) 55 proteins with similar abundance in both groups; (b) 23 proteins in both groups, but 7 of them were high abundance in medium with adaptive environment, while 16 high abundance proteins were in medium without adaptive environment; (c) 17 proteins in medium with adaptive environment only; and (d) 8 proteins in medium without adaptive environment only. The results provide a foundation for improving understanding of the molecular mechanisms associated with the beneficial effects of low dose radiation that, in turn, will have an important impact on radiation risk estimation. Hence, these studies are highly relevant to radiation protection due to an increased use of low dose radiation in daily life (e.g., medical diagnosis or airport safety) or an unavoidable exposure to low level background radiation.
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Hormesis by Low Dose Radiation Effects: Low-Dose Cancer Risk Modeling Must Recognize Up-Regulation of Protection. THERAPEUTIC NUCLEAR MEDICINE 2012. [DOI: 10.1007/174_2012_686] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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45
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Hertel-Aas T, Brunborg G, Jaworska A, Salbu B, Oughton DH. Effects of different gamma exposure regimes on reproduction in the earthworm Eisenia fetida (Oligochaeta). THE SCIENCE OF THE TOTAL ENVIRONMENT 2011; 412-413:138-147. [PMID: 22033357 DOI: 10.1016/j.scitotenv.2011.09.037] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2011] [Revised: 09/06/2011] [Accepted: 09/14/2011] [Indexed: 05/31/2023]
Abstract
Ecological risk assessment of ionising radiation requires knowledge about the responses of individuals and populations to chronic exposures, including situations when exposure levels change over time. The present study investigated processes such as recovery and the adaptive response with respect to reproduction endpoints in the earthworm Eisenia fetida exposed to (60)Co γ-radiation. Furthermore, a crossed experiment was performed to investigate the influence of F0 parental and F1 embryonic irradiation history on the response of irradiated or non-irradiated F1 offspring. Recovery: The sterility induced by sub-chronic exposure at 17 m Gy/h (accumulated dose: 25 Gy) was temporary, and 8 weeks after irradiation the worms had regained their reproductive capacity (number of viable offspring produced per adult per week). Adaptive response: Adult worms were continuously exposed at a low priming dose rate of 0.14 mGy/h for 12 weeks (accumulated dose: 0.24 Gy), followed by 14 weeks exposure at a challenge dose rate of 11 mGy/h. The results suggest a lack of adaptive response, since there were no significant differences in the effects on reproduction capacity between the primed and the unprimed groups after challenge doses ranging from 7.6 to 27 Gy. Crossed experiment: The effects of exposure at 11 mGy/h for 21 weeks on growth, sexual maturation and reproduction of offspring, derived either from parent worms and cocoons both exposed at 11 mGy/h, or from non-irradiated parents and cocoons (total accumulated dose 44 and 38 Gy, respectively) were compared. There were no significant differences between the two exposed offspring groups for any of the endpoints. The reproduction capacity was very low for both groups compared to the controls, but the reproduction seemed to be maintained at the reduced level, which could indicate acclimatisation or stabilisation. Finally, parental and embryonic exposures at 11 mGy/h did not affect reproduction in the F1 offspring as adults.
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Affiliation(s)
- Turid Hertel-Aas
- Department of Plant and Environmental Sciences, Norwegian University of Life Sciences, P.O. Box 5003, 1432 Aas, Norway.
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Abstract
Residential radon has been found to be associated with lung cancer in epidemiological/ecological studies and the researchers have inappropriately concluded that residential radon causes lung cancer. Their conclusion relates to the linear-no-threshold (LNT) hypothesis-based, risk-assessment paradigm; however, the LNT hypothesis has been invalidated in numerous studies. It is shown in this paper that our hormetic relative risk (HRR) model is consistent with lung cancer data where detailed measurements of radon in each home were carried out. Based on the HRR model, low-level radon radioactive progeny is credited for activated natural protection (ANP) against lung cancer including smoking-related lung cancer. The proportion B(x) (benefit function) of ANP beneficiaries increases as the average radon level x increases to near the Environmental Protection Agency's action level of 4 picocuries/L (approximately 150 Bq m(-3)). As the average level of radon increases to somewhat above the action level, ANP beneficiaries progressively decrease to zero (B(x) decreases to 0), facilitating the occurrence of smoking-related lung cancers as well as those related to other less important risk factors. Thus, residential radon does not appear to cause lung cancer but rather to protect, in an exposure-level-dependent manner, from its induction by other agents (e.g., cigarette-smoke-related carcinogens).
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Farooque A, Mathur R, Verma A, Kaul V, Bhatt AN, Adhikari JS, Afrin F, Singh S, Dwarakanath BS. Low-dose radiation therapy of cancer: role of immune enhancement. Expert Rev Anticancer Ther 2011; 11:791-802. [PMID: 21554054 DOI: 10.1586/era.10.217] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The efficacy of conventional radiation therapy, one of the most widely used treatment modalities of cancer, is limited by resistance of tumors as well as normal tissue toxicity. In the last decade, several studies have shown that protocols using low-dose radiation (LDR) are more effective in providing local tumor control with negligible normal tissue toxicity. LDR stimulates antioxidant capacity, repair of DNA damage, apoptosis and induction of immune responses, which might be collectively responsible for providing effective local tumor control. This article focuses on the immunostimulatory effects of LDR in in vivo models and its clinical efficacy, supporting the use of LDR regimens (alone or as adjuvant) as an anticancer treatment.
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Affiliation(s)
- Abdullah Farooque
- Division of Radiation Biosciences, Institute of Nuclear Medicine and Allied Sciences, Brig. SK Mazumdar Road, Delhi 110 0054, India
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Rithidech KN, Udomtanakunchai C, Honikel LM, Whorton EB. No Evidence for the In Vivo Induction of Genomic Instability by Low Doses of CS Gamma Rays in Bone Marrow Cells of BALB/CJ and C57BL/6J Mice. Dose Response 2011; 10:11-36. [PMID: 22423226 DOI: 10.2203/dose-response.11-002.rithidech] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
In spite of extensive research, assessment of potential health risks associated with exposure to low-dose (≤ 0.1 Gy) radiation is still challenging. We evaluated the in vivo induction of genomic instability, expressed as late-occurring chromosome aberrations, in bone-marrow cells of two strains of mouse with different genetic background, i.e. the radiosensitive BALB/cJ and the radioresistant C57BL/6J strains following a whole-body exposure to varying doses of (137)Cs gamma rays (0, 0.05, 0.1, and 1.0 Gy). A total of five mice per dose per strain were sacrificed at various times post-irradiation up to 6 months for sample collections. Three-color fluorescence in situ hybridization for mouse chromosomes 1, 2, and 3 was used for the analysis of stable-aberrations in metaphase-cells. All other visible gross structural-abnormalities involving non-painted-chromosomes were also evaluated on the same metaphase-cells used for scoring the stable-aberrations of painted-chromosomes. Our new data demonstrated in bone-marrow cells from both strains that low doses of low LET-radiation (as low as 0.05 Gy) are incapable of inducing genomic instability but are capable of reducing specific aberration-types below the spontaneous rate with time post-irradiation. However, the results showed the induction of genomic instability by 1.0 Gy of (137)Cs gamma rays in the radiosensitive strain only.
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Zhizhina GP. The effects of low doses of low-intensity ionizing radiation on DNA structure and function. Biophysics (Nagoya-shi) 2011. [DOI: 10.1134/s0006350911040312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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50
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Abstract
A stochastic model based on the Markov Chain Monte Carlo process is used to describe responses to ionizing radiation in a group of cells. The results show that where multiple relationships linearly depending on the dose are introduced, the overall reaction shows a threshold, and, generally, a non-linear response. Such phenomena have been observed and reported in a number of papers. The present model permits the inclusion of adaptive responses and bystander effects that can lead to hormetic effects. In addition, the model allows for incorporating various time-dependent phenomena. Essentially, all known biological effects can be reproduced using the proposed model.
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