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Rouchka EC, Flight RM, Fasciotto BH, Estrada R, Eaton JW, Patibandla PK, Waigel SJ, Li D, Kirtley JK, Sethu P, Keynton RS. Transcriptional profile of immediate response to ionizing radiation exposure. GENOMICS DATA 2015; 7:82-5. [PMID: 26981369 PMCID: PMC4778620 DOI: 10.1016/j.gdata.2015.11.027] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Accepted: 11/30/2015] [Indexed: 01/22/2023]
Abstract
Astronauts participating in long duration space missions are likely to be exposed to ionizing radiation associated with highly energetic and charged heavy particles. Previously proposed gene biomarkers for radiation exposure include phosphorylated H2A Histone Family, Member X (γH2AX), Tumor Protein 53 (TP53), and Cyclin-Dependent Kinase Inhibitor 1A (CDKN1A). However, transcripts of these genes may not be the most suitable biomarkers for radiation exposure due to a lack of sensitivity or specificity. As part of a larger effort to develop lab-on-a-chip methods for detecting radiation exposure events using blood samples, we designed a dose–course microarray study in order to determine coding and non-coding RNA transcripts undergoing differential expression immediately following radiation exposure. The main goal was to elicit a small set of sensitive and specific radiation exposure biomarkers at low, medium, and high levels of ionizing radiation exposure. Four separate levels of radiation were considered: 0 Gray (Gy) control; 0.3 Gy; 1.5 Gy; and 3.0 Gy with four replicates at each radiation level. This report includes raw gene expression data files from the resulting microarray experiments from all three radiation levels ranging from a lower, typical exposure than an astronaut might see (0.3 Gy) to high, potentially lethal, levels of radiation (3.0 Gy). The data described here is available in NCBI's Gene Expression Omnibus (GEO), accession GSE64375.
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Affiliation(s)
- Eric C Rouchka
- Department of Computer Engineering and Computer Science, University of Louisville, Louisville, KY 40292, United States; Kentucky Biomedical Research Infrastructure Network Bioinformatics Core, University of Louisville, Louisville, KY 40292, United States
| | - Robert M Flight
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY 40356, United States
| | - Brigitte H Fasciotto
- TheElectroOptics Research Institute and Nanotechnology Center, University of Louisville, Louisville, KY 40292, United States
| | - Rosendo Estrada
- Department of Bioengineering, University of Louisville, Louisville, KY 40292, United States
| | - John W Eaton
- Department of Medicine, University of Louisville, Louisville, KY 40292, United States; Department of Pharmacology and Toxicology, University of Louisville, Louisville, KY 40292, United States; James Graham Brown Cancer Center, University of Louisville, Louisville, KY 40202, United States
| | - Phani K Patibandla
- Division of Cardiovascular Disease, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, United States; Department of Biomedical Engineering, University of Alabama at Birmingham, Birmingham, AL 35294, United States
| | - Sabine J Waigel
- James Graham Brown Cancer Center, University of Louisville, Louisville, KY 40202, United States
| | - Dazhuo Li
- Department of Computer Engineering and Computer Science, University of Louisville, Louisville, KY 40292, United States
| | - John K Kirtley
- Department of Computer Engineering and Computer Science, University of Louisville, Louisville, KY 40292, United States
| | - Palaniappan Sethu
- Division of Cardiovascular Disease, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, United States; Department of Biomedical Engineering, University of Alabama at Birmingham, Birmingham, AL 35294, United States
| | - Robert S Keynton
- Department of Medicine, University of Louisville, Louisville, KY 40292, United States
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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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Molecular characterization of TP53 gene in human populations exposed to low-dose ionizing radiation. BIOMED RESEARCH INTERNATIONAL 2013; 2013:303486. [PMID: 23586029 PMCID: PMC3613089 DOI: 10.1155/2013/303486] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/01/2012] [Revised: 12/19/2012] [Accepted: 12/24/2012] [Indexed: 02/06/2023]
Abstract
Ionizing radiation, such as that emitted by uranium, may cause mutations and consequently lead to neoplasia in human cells. The TP53 gene acts to maintain genomic integrity and constitutes an important biomarker of susceptibility. The present study investigated the main alterations observed in exons 4, 5, 6, 7, and 8 of the TP53 gene and adjacent introns in Amazonian populations exposed to radioactivity. Samples were collected from 163 individuals. Occurrence of the following alterations was observed: (i) a missense exchange in exon 4 (Arg72Pro); (ii) 2 synonymous exchanges, 1 in exon 5 (His179His), and another in exon 6 (Arg213Arg); (iii) 4 intronic exchanges, 3 in intron 7 (C → T at position 13.436; C → T at position 13.491; T → G at position 13.511) and 1 in intron 8 (T → G at position 13.958). Alteration of codon 72 was found to be an important risk factor for cancer development (P = 0.024; OR = 6.48; CI: 1.29–32.64) when adjusted for age and smoking. Thus, TP53 gene may be an important biomarker for carcinogenesis susceptibility in human populations exposed to ionizing radiation.
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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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Howell EK, Gaschak SP, Griffith KDW, Rodgers BE. Radioadaptive Response Following In Utero Low-Dose Irradiation. Radiat Res 2012. [DOI: 10.1667/rr3029.1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Eric K. Howell
- Department of Biological Sciences and the Center for Environmental Radiation Studies, Texas Tech University, Lubbock, Texas; and
| | - Sergey P. Gaschak
- International Radioecology Laboratory, Slavutych, Kyiv Region 07100, Ukraine
| | - Kenneth D. W. Griffith
- Department of Biological Sciences and the Center for Environmental Radiation Studies, Texas Tech University, Lubbock, Texas; and
| | - Brenda E. Rodgers
- Department of Biological Sciences and the Center for Environmental Radiation Studies, Texas Tech University, Lubbock, Texas; and
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Abstract
Adaptive responses to low doses of low LET radiation occur in all organisms thus far examined, from single cell lower eukaryotes to mammals. These responses reduce the deleterious consequences of DNA damaging events, including radiation-induced or spontaneous cancer and non-cancer diseases in mice. The adaptive response in mammalian cells and mammals operates within a certain window that can be defined by upper and lower dose thresholds, typically between about 1 and 100 mGy for a single low dose rate exposure. However, these thresholds for protection are not a fixed function of total dose, but also vary with dose rate, additional radiation or non-radiation stressors, tissue type and p53 functional status. Exposures above the upper threshold are generally detrimental, while exposures below the lower threshold may or may not increase either cancer or non-cancer disease risk.
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Affiliation(s)
- Ronald E J Mitchel
- Radiation Protection Research and Instrumentation Branch, Atomic Energy of Canada Limited, Chalk River Laboratories, Chalk River, ON Canada
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Pazzaglia S, Pasquali E, Tanori M, Mancuso M, Leonardi S, di Majo V, Rebessi S, Saran A. Physical, heritable and age-related factors as modifiers of radiation cancer risk in patched heterozygous mice. Int J Radiat Oncol Biol Phys 2009; 73:1203-10. [PMID: 19201105 DOI: 10.1016/j.ijrobp.2008.10.068] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2008] [Revised: 10/15/2008] [Accepted: 10/16/2008] [Indexed: 10/21/2022]
Abstract
PURPOSE To address the tumorigenic potential of exposure to low/intermediate doses of ionizing radiation and to identify biological factors influencing tumor response in a mouse model highly susceptible to radiogenic cancer. METHODS AND MATERIALS Newborn Ptc1 heterozygous mice were exposed to X-ray doses of 100, 250, and 500 mGy, and tumor development was monitored for their lifetime. Additional groups were irradiated with the same doses and sacrificed at fixed times for determination of short-term endpoints, such as apoptosis and early preneoplastic lesions in cerebellum. Finally, groups of Ptc1 heterozygous mice were bred on the C57BL/6 background to study the influence of common variant genes on radiation response. RESULTS We have identified a significant effect of low-intermediate doses of radiation (250 and 500 mGy) in shortening mean survival and inducing early and more progressed stages of tumor development in the cerebellum of Ptc1(+/-) mice. In addition, we show that age at exposure and heritable factors are potent modifiers of radiation-related cancer risk. CONCLUSIONS The Ptc1 knockout mouse model offers a highly sensitive system that may potentially help to improve understanding and quantification of risk at low doses, such as doses experienced in occupational and medical exposures, and clarify the complex interactions between genetic and environmental factors underlying cancer susceptibility.
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Affiliation(s)
- Simonetta Pazzaglia
- Section of Toxicology and Biomedical Sciences, Biotechnologies, Agro-Industry and Health Protection Department, ENEA CR Casaccia, 00123 Rome, Italy.
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Mitchel REJ, Burchart P, Wyatt H. A Lower Dose Threshold for theIn VivoProtective Adaptive Response to Radiation. Tumorigenesis in Chronically Exposed Normal andTrp53Heterozygous C57BL/6 Mice. Radiat Res 2008; 170:765-75. [DOI: 10.1667/rr1414.1] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2008] [Accepted: 05/29/2008] [Indexed: 11/03/2022]
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Scott BR. It's time for a new low-dose-radiation risk assessment paradigm--one that acknowledges hormesis. Dose Response 2007; 6:333-51. [PMID: 19088900 PMCID: PMC2592992 DOI: 10.2203/dose-response.07-005.scott] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The current system of radiation protection for humans is based on the linear-no-threshold (LNT) risk-assessment paradigm. Perceived harm to irradiated nuclear workers and the public is mainly reflected through calculated hypothetical increased cancers. The LNT-based system of protection employs easy-to-implement measures of radiation exposure. Such measures include the equivalent dose (a biological-damage-potential-weighted measure) and the effective dose (equivalent dose multiplied by a tissue-specific relative sensitivity factor for stochastic effects). These weighted doses have special units such as the sievert (Sv) and millisievert (mSv, one thousandth of a sievert). Radiation-induced harm is controlled via enforcing exposure limits expressed as effective dose. Expected cancer cases can be easily computed based on the summed effective dose (person-sievert) for an irradiated group or population. Yet the current system of radiation protection needs revision because radiation-induced natural protection (hormesis) has been neglected. A novel, nonlinear, hormetic relative risk model for radiation-induced cancers is discussed in the context of establishing new radiation exposure limits for nuclear workers and the public.
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Affiliation(s)
- Bobby R Scott
- Lovelace Respiratory Research Institute, 2425 Ridgecrest Drive SE, Albuquerque, NM 87108, USA.
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Abstract
The Linear No Threshold (LNT) hypothesis states that ionizing radiation risk is directly proportional to dose, without a threshold. This hypothesis, along with a number of additional derived or auxiliary concepts such as radiation and tissue type weighting factors, and dose rate reduction factors, are used to calculate radiation risk estimates for humans, and are therefore fundamental for radiation protection practices. This system is based mainly on epidemiological data of cancer risk in human populations exposed to relatively high doses (above 100 mSv), with the results linearly extrapolated back to the low doses typical of current exposures. The system therefore uses dose as a surrogate for risk. There is now a large body of information indicating that, at low doses, the LNT hypothesis, along with most of the derived and auxiliary concepts, is incorrect. The use of dose as a predictor of risk needs to be re-examined and the use of dose limits, as a means of limiting risk needs to be re-evaluated. This re-evaluation could lead to large changes in radiation protection practices.
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Affiliation(s)
- R E J Mitchel
- Radiation Biology and Health Physics Branch, Atomic Energy of Canada Limited, Chalk River, Ontario, Canada.
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Scott BR, Di Palma J. Sparsely ionizing diagnostic and natural background radiations are likely preventing cancer and other genomic-instability-associated diseases. Dose Response 2006; 5:230-55. [PMID: 18648608 PMCID: PMC2477699 DOI: 10.2203/dose-response.06-002.scott] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Routine diagnostic X-rays (e.g., chest X-rays, mammograms, computed tomography scans) and routine diagnostic nuclear medicine procedures using sparsely ionizing radiation forms (e.g., beta and gamma radiations) stimulate the removal of precancerous neo-plastically transformed and other genomically unstable cells from the body (medical radiation hormesis). The indicated radiation hormesis arises because radiation doses above an individual-specific stochastic threshold activate a system of cooperative protective processes that include high-fidelity DNA repair/apoptosis (presumed p53 related), an auxiliary apoptosis process (PAM process) that is presumed p53-independent, and stimulated immunity. These forms of induced protection are called adapted protection because they are associated with the radiation adaptive response. Diagnostic X-ray sources, other sources of sparsely ionizing radiation used in nuclear medicine diagnostic procedures, as well as radioisotope-labeled immunoglobulins could be used in conjunction with apoptosis-sensitizing agents (e.g., the natural phenolic compound resveratrol) in curing existing cancer via low-dose fractionated or low-dose, low-dose-rate therapy (therapeutic radiation hormesis). Evidence is provided to support the existence of both therapeutic (curing existing cancer) and medical (cancer prevention) radiation hormesis. Evidence is also provided demonstrating that exposure to environmental sparsely ionizing radiations, such as gamma rays, protect from cancer occurrence and the occurrence of other diseases via inducing adapted protection (environmental radiation hormesis).
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Affiliation(s)
- Bobby R. Scott
- Lovelace Respiratory Research Institute, 2425 Ridgecrest Drive SE, Albuquerque, NM 87108
| | - Jennifer Di Palma
- Lovelace Respiratory Research Institute, 2425 Ridgecrest Drive SE, Albuquerque, NM 87108
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