1
|
Carrothers E, Appleby M, Lai V, Kozbenko T, Alomar D, Smith BJ, Hamada N, Hinton P, Ainsbury EA, Hocking R, Yauk C, Wilkins RC, Chauhan V. AOP report: Development of an adverse outcome pathway for deposition of energy leading to cataracts. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2024. [PMID: 38644659 DOI: 10.1002/em.22594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2024] [Accepted: 03/21/2024] [Indexed: 04/23/2024]
Abstract
Cataracts are one of the leading causes of blindness, with an estimated 95 million people affected worldwide. A hallmark of cataract development is lens opacification, typically associated not only with aging but also radiation exposure as encountered by interventional radiologists and astronauts during the long-term space mission. To better understand radiation-induced cataracts, the adverse outcome pathway (AOP) framework was used to structure and evaluate knowledge across biological levels of organization (e.g., macromolecular, cell, tissue, organ, organism and population). AOPs identify a sequence of key events (KEs) causally connected by key event relationships (KERs) beginning with a molecular initiating event to an adverse outcome (AO) of relevance to regulatory decision-making. To construct the cataract AO and retrieve evidence to support it, a scoping review methodology was used to filter, screen, and review studies based on the modified Bradford Hill criteria. Eight KEs were identified that were moderately supported by empirical evidence (e.g., dose-, time-, incidence-concordance) across the adjacent (directly linked) relationships using well-established endpoints. Over half of the evidence to justify the KER linkages was derived from the evidence stream of biological plausibility. Early KEs of oxidative stress and protein modifications had strong linkages to downstream KEs and could be the focus of countermeasure development. Several identified knowledge gaps and inconsistencies related to the quantitative understanding of KERs which could be the basis of future research, most notably directed to experiments in the range of low or moderate doses and dose-rates, relevant to radiation workers and other occupational exposures.
Collapse
Affiliation(s)
- Emma Carrothers
- Consumer and Clinical Radiation Protection Bureau, Environmental and Radiation Health Sciences Directorate, Health Canada, Ottawa, Ontario, Canada
| | - Meghan Appleby
- Consumer and Clinical Radiation Protection Bureau, Environmental and Radiation Health Sciences Directorate, Health Canada, Ottawa, Ontario, Canada
| | - Vita Lai
- Consumer and Clinical Radiation Protection Bureau, Environmental and Radiation Health Sciences Directorate, Health Canada, Ottawa, Ontario, Canada
| | - Tatiana Kozbenko
- Consumer and Clinical Radiation Protection Bureau, Environmental and Radiation Health Sciences Directorate, Health Canada, Ottawa, Ontario, Canada
| | - Dalya Alomar
- Consumer and Clinical Radiation Protection Bureau, Environmental and Radiation Health Sciences Directorate, Health Canada, Ottawa, Ontario, Canada
| | - Benjamin J Smith
- Consumer and Clinical Radiation Protection Bureau, Environmental and Radiation Health Sciences Directorate, Health Canada, Ottawa, Ontario, Canada
| | - Nobuyuki Hamada
- Biology and Environmental Chemistry Division, Sustainable System Research Laboratory, Central Research Institute of Electric Power Industry (CRIEPI), Chiba, Japan
| | - Patricia Hinton
- Defense Research & Development Canada, Canadian Forces Environmental Medicine Establishment, Toronto, Ontario, Canada
| | - Elizabeth A Ainsbury
- Radiation, Chemical and Environmental Hazards Division, UK Health Security Agency, Birmingham, UK
- Environmental Research Group within the School of Public Health, Faculty of Medicine at Imperial College of Science, Technology and Medicine, London, UK
| | - Robyn Hocking
- Learning and Knowledge and Library Services, Health Canada, Ottawa, Ontario, Canada
| | - Carole Yauk
- Department of Biology, University of Ottawa, Ottawa, Ontario, Canada
| | - Ruth C Wilkins
- Consumer and Clinical Radiation Protection Bureau, Environmental and Radiation Health Sciences Directorate, Health Canada, Ottawa, Ontario, Canada
| | - Vinita Chauhan
- Consumer and Clinical Radiation Protection Bureau, Environmental and Radiation Health Sciences Directorate, Health Canada, Ottawa, Ontario, Canada
| |
Collapse
|
2
|
Blakely EA. The 20th Gray lecture 2019: health and heavy ions. Br J Radiol 2020; 93:20200172. [PMID: 33021811 PMCID: PMC8519642 DOI: 10.1259/bjr.20200172] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2020] [Revised: 09/11/2020] [Accepted: 09/18/2020] [Indexed: 12/11/2022] Open
Abstract
OBJECTIVE Particle radiobiology has contributed new understanding of radiation safety and underlying mechanisms of action to radiation oncology for the treatment of cancer, and to planning of radiation protection for space travel. This manuscript will highlight the significance of precise physical and biologically effective dosimetry to this translational research for the benefit of human health.This review provides a brief snapshot of the evolving scientific basis for, and the complex current global status, and remaining challenges of hadron therapy for the treatment of cancer. The need for particle radiobiology for risk planning in return missions to the Moon, and exploratory deep-space missions to Mars and beyond are also discussed. METHODS Key lessons learned are summarized from an impressive collective literature published by an international cadre of multidisciplinary experts in particle physics, radiation chemistry, medical physics of imaging and treatment planning, molecular, cellular, tissue radiobiology, biology of microgravity and other stressors, theoretical modeling of biophysical data, and clinical results with accelerator-produced particle beams. RESULTS Research pioneers, many of whom were Nobel laureates, led the world in the discovery of ionizing radiations originating from the Earth and the Cosmos. Six radiation pioneers led the way to hadron therapy and the study of charged particles encountered in outer space travel. Worldwide about 250,000 patients have been treated for cancer, or other lesions such as arteriovenous malformations in the brain between 1954 and 2019 with charged particle radiotherapy, also known as hadron therapy. The majority of these patients (213,000) were treated with proton beams, but approximately 32,000 were treated with carbon ion radiotherapy. There are 3500 patients who have been treated with helium, pions, neon or other ions. There are currently 82 facilities operating to provide ion beam clinical treatments. Of these, only 13 facilities located in Asia and Europe are providing carbon ion beams for preclinical, clinical, and space research. There are also numerous particle physics accelerators worldwide capable of producing ion beams for research, but not currently focused on treating patients with ion beam therapy but are potentially available for preclinical and space research. Approximately, more than 550 individuals have traveled into Lower Earth Orbit (LEO) and beyond and returned to Earth. CONCLUSION Charged particle therapy with controlled beams of protons and carbon ions have significantly impacted targeted cancer therapy, eradicated tumors while sparing normal tissue toxicities, and reduced human suffering. These modalities still require further optimization and technical refinements to reduce cost but should be made available to everyone in need worldwide. The exploration of our Universe in space travel poses the potential risk of exposure to uncontrolled charged particles. However, approaches to shield and provide countermeasures to these potential radiation hazards in LEO have allowed an amazing number of discoveries currently without significant life-threatening medical consequences. More basic research with components of the Galactic Cosmic Radiation field are still required to assure safety involving space radiations and combined stressors with microgravity for exploratory deep space travel. ADVANCES IN KNOWLEDGE The collective knowledge garnered from the wealth of available published evidence obtained prior to particle radiation therapy, or to space flight, and the additional data gleaned from implementing both endeavors has provided many opportunities for heavy ions to promote human health.
Collapse
|
3
|
Brooks AL. The impact of dose rate on the linear no threshold hypothesis. Chem Biol Interact 2019; 301:68-80. [PMID: 30763551 DOI: 10.1016/j.cbi.2018.12.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Revised: 11/17/2018] [Accepted: 12/11/2018] [Indexed: 12/13/2022]
Abstract
The goal of this manuscript is to define the role of dose rate and dose protraction on the induction of biological changes at all levels of biological organization. Both total dose and the time frame over which it is delivered are important as the body has great capacity to repair all types of biological damage. The importance of dose rate has been recognized almost from the time that radiation was discovered and has been included in radiation standards as a Dose, Dose Rate, Effectiveness Factor (DDREF) and a Dose Rate Effectiveness Factor (DREF). This manuscript will evaluate the role of dose rate at the molecular, cellular, tissue, experimental animals and humans to demonstrate that dose rate is an important variable in estimating radiation cancer risk and other biological effects. The impact of low-dose rates on the Linear-No-Threshold Hypothesis (LNTH) will be reviewed since if the LNTH is not valid it is not possible to calculate a single value for a DDREF or DREF. Finally, extensive human experience is briefly reviewed to show that the radiation risks are not underestimated and that radiation at environmental levels has limited impact on total human cancer risk.
Collapse
Affiliation(s)
- Antone L Brooks
- Environmental Science, Washington State University, Richland, WA, USA.
| |
Collapse
|
4
|
Coppeta L, Pietroiusti A, Neri A, Spataro A, De Angelis E, Perrone S, Magrini A. Risk of radiation-induced lens opacities among surgeons and interventional medical staff. Radiol Phys Technol 2018; 12:26-29. [PMID: 30478501 DOI: 10.1007/s12194-018-0487-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Revised: 10/21/2018] [Accepted: 11/01/2018] [Indexed: 01/02/2023]
Abstract
The main effect of ionizing radiation on the eyes is the onset of posterior cortical and subcapsular cataracts. Recent studies have raised questions about the mechanism of ocular damage and the threshold dose for the onset of such effects. Currently, operators may be exposed to ionizing radiation during surgical procedures. It has been estimated that urologists can be exposed to an annual dose close to or above 20 mSv/year. The aim of our study was to evaluate the frequency of cataracts in a group of professional radiological operators to verify their possible association with the radiation dose to the crystalline lens and the tasks performed. The records of 73 health workers exposed to ionizing radiation were reviewed. The average annual dose to the crystalline lens, the number of years of exposure, and the presence of radiation-compatible opacities were assessed for all operators. Lenticular opacities were observed in 16.4% of subjects. The presence of alterations was associated with exposure doses below 10 mSv and > 10 years' experience in fluoroscopically guided procedures. Based on our results, protection of the crystalline lens against exposure to ionizing radiation by means of goggles is recommended. In addition, examination of the lens via slit lamp examination is recommended for all operators involved in interventional procedures with the current levels of radiation exposure.
Collapse
Affiliation(s)
- Luca Coppeta
- Department of Occupational Medicine, University of Rome "Tor Vergata", Viale Oxford 81, 00133, Rome, Italy.
| | - Antonio Pietroiusti
- Department of Occupational Medicine, University of Rome "Tor Vergata", Viale Oxford 81, 00133, Rome, Italy
| | - Anna Neri
- Department of Occupational Medicine, University of Rome "Tor Vergata", Viale Oxford 81, 00133, Rome, Italy
| | - Agostino Spataro
- Department of Occupational Medicine, University of Rome "Tor Vergata", Viale Oxford 81, 00133, Rome, Italy
| | - Elisabetta De Angelis
- Department of Occupational Medicine, University of Rome "Tor Vergata", Viale Oxford 81, 00133, Rome, Italy
| | - Stefano Perrone
- Department of Occupational Medicine, University of Rome "Tor Vergata", Viale Oxford 81, 00133, Rome, Italy
| | - Andrea Magrini
- Department of Occupational Medicine, University of Rome "Tor Vergata", Viale Oxford 81, 00133, Rome, Italy
| |
Collapse
|
5
|
Dauer LT. Seeing through a glass darkly and taking the next right steps. Eur J Epidemiol 2018; 33:1135-1137. [PMID: 30390232 DOI: 10.1007/s10654-018-0458-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Accepted: 10/26/2018] [Indexed: 12/17/2022]
Affiliation(s)
- Lawrence T Dauer
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY, 10065, USA.
- Department of Radiology, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY, 10065, USA.
| |
Collapse
|
6
|
Dauer LT, Ainsbury EA, Dynlacht J, Hoel D, Klein BEK, Mayer D, Prescott CR, Thornton RH, Vano E, Woloschak GE, Flannery CM, Goldstein LE, Hamada N, Tran PK, Grissom MP, Blakely EA. Guidance on radiation dose limits for the lens of the eye: overview of the recommendations in NCRP Commentary No. 26. Int J Radiat Biol 2017; 93:1015-1023. [DOI: 10.1080/09553002.2017.1304669] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- Lawrence T. Dauer
- Radiology & Medical Physics, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Elizabeth A. Ainsbury
- Centre for Radiation, Chemical and Environmental Hazards (CRCE), Public Health England, Oxford, UK
| | - Joseph Dynlacht
- Radiation Oncology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - David Hoel
- Public Health Services, Medical University of South Carolina, Charleston, SC, USA
| | - Barbara E. K. Klein
- Ophthalmology & Visual Sciences, University of Wisconsin-Madison, Madison, WI, USA
| | - Donald Mayer
- Special Projects, Indian Point Energy Center, Buchanan, NY, USA
| | | | - Raymond H. Thornton
- Radiology & Medical Physics, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Eliseo Vano
- Radiology, Complutense University, Madrid, Spain
| | | | - Cynthia M. Flannery
- Office of Nuclear Material Safety and Safeguards, U.S. Nuclear Regulatory Commission, Rockville, MD, USA
| | - Lee E. Goldstein
- Pathology & Laboratory Medicine, Boston University, Boston, MA, USA
| | - Nobuyuki Hamada
- Nuclear Technology Research Center, Central Research Institute of Electric Power Industry, Tokyo, Japan
| | - Phung K. Tran
- Radiation Safety Program, Electric Power Research Institute, Palo Alto, CA, USA
| | - Michael P. Grissom
- National Council on Radiation Protection and Measurements, Bethesda, MD, USA
| | - Eleanor A. Blakely
- Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| |
Collapse
|
7
|
Brooks AL, Hoel DG, Preston RJ. The role of dose rate in radiation cancer risk: evaluating the effect of dose rate at the molecular, cellular and tissue levels using key events in critical pathways following exposure to low LET radiation. Int J Radiat Biol 2016; 92:405-26. [PMID: 27266588 PMCID: PMC4975094 DOI: 10.1080/09553002.2016.1186301] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Revised: 03/14/2016] [Accepted: 05/02/2016] [Indexed: 12/19/2022]
Abstract
PURPOSE This review evaluates the role of dose rate on cell and molecular responses. It focuses on the influence of dose rate on key events in critical pathways in the development of cancer. This approach is similar to that used by the U.S. EPA and others to evaluate risk from chemicals. It provides a mechanistic method to account for the influence of the dose rate from low-LET radiation, especially in the low-dose region on cancer risk assessment. Molecular, cellular, and tissues changes are observed in many key events and change as a function of dose rate. The magnitude and direction of change can be used to help establish an appropriate dose rate effectiveness factor (DREF). CONCLUSIONS Extensive data on key events suggest that exposure to low dose-rates are less effective in producing changes than high dose rates. Most of these data at the molecular and cellular level support a large (2-30) DREF. In addition, some evidence suggests that doses delivered at a low dose rate decrease damage to levels below that observed in the controls. However, there are some data human and mechanistic data that support a dose-rate effectiveness factor of 1. In summary, a review of the available molecular, cellular and tissue data indicates that not only is dose rate an important variable in understanding radiation risk but it also supports the selection of a DREF greater than one as currently recommended by ICRP ( 2007 ) and BEIR VII (NRC/NAS 2006 ).
Collapse
Affiliation(s)
- Antone L. Brooks
- Retired Professor, Environmental Science, Washington State University,
Richland,
Washington,
USA
| | - David G. Hoel
- Medical University of South Carolina, Epidemiology,
Charleston South Carolina,
USA
| | - R. Julian Preston
- US Environmental Protection Agency, National Health and Environmental Effects Research Laboratory (NHEERL) (MD B105-01), RTP,
USA
| |
Collapse
|
8
|
Sridharan DM, Asaithamby A, Blattnig SR, Costes SV, Doetsch PW, Dynan WS, Hahnfeldt P, Hlatky L, Kidane Y, Kronenberg A, Naidu MD, Peterson LE, Plante I, Ponomarev AL, Saha J, Snijders AM, Srinivasan K, Tang J, Werner E, Pluth JM. Evaluating biomarkers to model cancer risk post cosmic ray exposure. LIFE SCIENCES IN SPACE RESEARCH 2016; 9:19-47. [PMID: 27345199 PMCID: PMC5613937 DOI: 10.1016/j.lssr.2016.05.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Accepted: 05/11/2016] [Indexed: 06/06/2023]
Abstract
Robust predictive models are essential to manage the risk of radiation-induced carcinogenesis. Chronic exposure to cosmic rays in the context of the complex deep space environment may place astronauts at high cancer risk. To estimate this risk, it is critical to understand how radiation-induced cellular stress impacts cell fate decisions and how this in turn alters the risk of carcinogenesis. Exposure to the heavy ion component of cosmic rays triggers a multitude of cellular changes, depending on the rate of exposure, the type of damage incurred and individual susceptibility. Heterogeneity in dose, dose rate, radiation quality, energy and particle flux contribute to the complexity of risk assessment. To unravel the impact of each of these factors, it is critical to identify sensitive biomarkers that can serve as inputs for robust modeling of individual risk of cancer or other long-term health consequences of exposure. Limitations in sensitivity of biomarkers to dose and dose rate, and the complexity of longitudinal monitoring, are some of the factors that increase uncertainties in the output from risk prediction models. Here, we critically evaluate candidate early and late biomarkers of radiation exposure and discuss their usefulness in predicting cell fate decisions. Some of the biomarkers we have reviewed include complex clustered DNA damage, persistent DNA repair foci, reactive oxygen species, chromosome aberrations and inflammation. Other biomarkers discussed, often assayed for at longer points post exposure, include mutations, chromosome aberrations, reactive oxygen species and telomere length changes. We discuss the relationship of biomarkers to different potential cell fates, including proliferation, apoptosis, senescence, and loss of stemness, which can propagate genomic instability and alter tissue composition and the underlying mRNA signatures that contribute to cell fate decisions. Our goal is to highlight factors that are important in choosing biomarkers and to evaluate the potential for biomarkers to inform models of post exposure cancer risk. Because cellular stress response pathways to space radiation and environmental carcinogens share common nodes, biomarker-driven risk models may be broadly applicable for estimating risks for other carcinogens.
Collapse
Affiliation(s)
| | | | - Steve R Blattnig
- Langley Research Center, Langley Research Center (LaRC), VA, United States
| | - Sylvain V Costes
- Lawrence Berkeley National Laboratory, Berkeley, CA, United States
| | | | | | | | - Lynn Hlatky
- CCSB-Tufts School of Medicine, Boston, MA, United States
| | - Yared Kidane
- Wyle Science, Technology & Engineering Group, Houston, TX, United States
| | - Amy Kronenberg
- Lawrence Berkeley National Laboratory, Berkeley, CA, United States
| | - Mamta D Naidu
- CCSB-Tufts School of Medicine, Boston, MA, United States
| | - Leif E Peterson
- Houston Methodist Research Institute, Houston, TX, United States
| | - Ianik Plante
- Wyle Science, Technology & Engineering Group, Houston, TX, United States
| | - Artem L Ponomarev
- Wyle Science, Technology & Engineering Group, Houston, TX, United States
| | - Janapriya Saha
- UT Southwestern Medical Center, Dallas, TX, United States
| | | | | | - Jonathan Tang
- Exogen Biotechnology, Inc., Berkeley, CA, United States
| | | | - Janice M Pluth
- Lawrence Berkeley National Laboratory, Berkeley, CA, United States.
| |
Collapse
|
9
|
Dauer LT, Ainsbury EA, Dynlacht J, Hoel D, Klein BEK, Mayer D, Prescott CR, Thornton RH, Vano E, Woloschak GE, Flannery CM, Goldstein LE, Hamada N, Tran PK, Grissom MP, Blakely EA. Status of NCRP Scientific Committee 1-23 Commentary on Guidance on Radiation Dose Limits for the Lens of the Eye. HEALTH PHYSICS 2016; 110:182-184. [PMID: 26717175 PMCID: PMC4697269 DOI: 10.1097/hp.0000000000000412] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Previous National Council on Radiation Protection and Measurements (NCRP) publications have addressed the issues of risk and dose limitation in radiation protection and included guidance on specific organs and the lens of the eye. NCRP decided to prepare an updated commentary intended to enhance the previous recommendations provided in earlier reports. The NCRP Scientific Committee 1-23 (SC 1-23) is charged with preparing a commentary that will evaluate recent studies on the radiation dose response for the development of cataracts and also consider the type and severity of the cataracts as well as the dose rate; provide guidance on whether existing dose limits to the lens of the eye should be changed in the United States; and suggest research needs regarding radiation effects on and dose limits to the lens of the eye. A status of the ongoing work of SC 1-23 was presented at the Annual Meeting, "Changing Regulations and Radiation Guidance: What Does the Future Hold?" The following represents a synopsis of a few main points in the current draft commentary. It is likely that several changes will be forthcoming as SC 1-23 responds to subject matter expert review and develops a final document, expected by mid 2016.
Collapse
Affiliation(s)
- Lawrence T Dauer
- *Memorial Sloan Kettering Cancer Center, New York, NY; †Public Health England, Oxford, United Kingdom; ‡Indiana University School of Medicine, Indianapolis, IN; §Medical University of South Carolina, Charleston, SC; **University of Wisconsin-Madison, Madison, WI; ††Indian Point Energy Center, Buchanan, NY; ‡‡Johns Hopkins Medicine, Bel Air, MD; §§Complutense University, Madrid, Spain; ***Northwestern University, Chicago, IL; †††U.S. Nuclear Regulatory Commission, Rockville, MD; ‡‡‡Boston University, Boston, MA; §§§Central Research Institute of Electric Power Industry, Tokyo, Japan; ****Electric Power Research Institute, Palo Alto, CA; ††††National Council on Radiation Protection and Measurements, Bethesda, MD; ‡‡‡‡Lawrence Berkeley National Laboratory, Berkeley, CA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
10
|
Li Z, Wang H, Wang Y, Murnane JP, Dynan WS. Effect of radiation quality on mutagenic joining of enzymatically-induced DNA double-strand breaks in previously irradiated human cells. Radiat Res 2014; 182:573-9. [PMID: 25329962 DOI: 10.1667/rr13723.1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Previous work has shown that high charge and energy particle irradiation of human cells evokes a mutagenic repair phenotype, defined by increased mutagenic repair of new double-strand breaks that are introduced enzymatically, days or weeks after the initial irradiation. The effect was seen originally with 600 MeV/u (56)Fe particles, which have a linear energy transfer (LET) value of 174 keV/μm, but not with X rays or γ rays (LET ≤ 2 keV/μm). To better define the radiation quality dependence of the phenomenon, we tested two ions with intermediate LET values, 1,000 MeV/u (48)Ti (LET = 108 keV/μm) and 300 MeV/u (28)Si (LET = 69 keV/μm). These experiments used a previously validated assay, where a rare-cutting nuclease introduces double-strand breaks in two reporter transgene cassettes, which are located on different chromosomes. Deletions of a block of sequence in one of the cassettes, or translocations between cassettes, are measured independently using a multicolor fluorescence assay. The results showed that (48)Ti was a potent, but transient, inducer of mutagenic repair, based on increased frequency of nuclease-induced translocations. The (48)Ti ions did not affect the frequency of nuclease-induced deletions. The (28)Si ions had no measurable effect on either endpoint. There was a close correlation between the induction of the mutagenic repair phenomenon and the frequency of micronuclei in the targeted population (R(2) = 0.74), whereas there was no apparent correlation with radiation-induced cell inactivation. Together, these results better define the radiation quality dependence of the mutagenic repair phenomenon and establish its correlation, or lack of correlation, with other endpoints.
Collapse
Affiliation(s)
- Zhentian Li
- a Department of Radiation Oncology and Winship Cancer Institute, Emory University School of Medicine, Emory University, Atlanta, Georgia
| | | | | | | | | |
Collapse
|
11
|
Space Radiation: The Number One Risk to Astronaut Health beyond Low Earth Orbit. Life (Basel) 2014; 4:491-510. [PMID: 25370382 PMCID: PMC4206856 DOI: 10.3390/life4030491] [Citation(s) in RCA: 154] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Revised: 08/06/2014] [Accepted: 08/21/2014] [Indexed: 01/04/2023] Open
Abstract
Projecting a vision for space radiobiological research necessitates understanding the nature of the space radiation environment and how radiation risks influence mission planning, timelines and operational decisions. Exposure to space radiation increases the risks of astronauts developing cancer, experiencing central nervous system (CNS) decrements, exhibiting degenerative tissue effects or developing acute radiation syndrome. One or more of these deleterious health effects could develop during future multi-year space exploration missions beyond low Earth orbit (LEO). Shielding is an effective countermeasure against solar particle events (SPEs), but is ineffective in protecting crew members from the biological impacts of fast moving, highly-charged galactic cosmic radiation (GCR) nuclei. Astronauts traveling on a protracted voyage to Mars may be exposed to SPE radiation events, overlaid on a more predictable flux of GCR. Therefore, ground-based research studies employing model organisms seeking to accurately mimic the biological effects of the space radiation environment must concatenate exposures to both proton and heavy ion sources. New techniques in genomics, proteomics, metabolomics and other “omics” areas should also be intelligently employed and correlated with phenotypic observations. This approach will more precisely elucidate the effects of space radiation on human physiology and aid in developing personalized radiological countermeasures for astronauts.
Collapse
|
12
|
Li M, Gonon G, Buonanno M, Autsavapromporn N, de Toledo SM, Pain D, Azzam EI. Health risks of space exploration: targeted and nontargeted oxidative injury by high-charge and high-energy particles. Antioxid Redox Signal 2014; 20:1501-23. [PMID: 24111926 PMCID: PMC3936510 DOI: 10.1089/ars.2013.5649] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
SIGNIFICANCE During deep space travel, astronauts are often exposed to high atomic number (Z) and high-energy (E) (high charge and high energy [HZE]) particles. On interaction with cells, these particles cause severe oxidative injury and result in unique biological responses. When cell populations are exposed to low fluences of HZE particles, a significant fraction of the cells are not traversed by a primary radiation track, and yet, oxidative stress induced in the targeted cells may spread to nearby bystander cells. The long-term effects are more complex because the oxidative effects persist in progeny of the targeted and affected bystander cells, which promote genomic instability and may increase the risk of age-related cancer and degenerative diseases. RECENT ADVANCES Greater understanding of the spatial and temporal features of reactive oxygen species bursts along the tracks of HZE particles, and the availability of facilities that can simulate exposure to space radiations have supported the characterization of oxidative stress from targeted and nontargeted effects. CRITICAL ISSUES The significance of secondary radiations generated from the interaction of the primary HZE particles with biological material and the mitigating effects of antioxidants on various cellular injuries are central to understanding nontargeted effects and alleviating tissue injury. FUTURE DIRECTIONS Elucidation of the mechanisms underlying the cellular responses to HZE particles, particularly under reduced gravity and situations of exposure to additional radiations, such as protons, should be useful in reducing the uncertainty associated with current models for predicting long-term health risks of space radiation. These studies are also relevant to hadron therapy of cancer.
Collapse
Affiliation(s)
- Min Li
- 1 Department of Radiology, Cancer Center, Rutgers University-New Jersey Medical School , Newark, New Jersey
| | | | | | | | | | | | | |
Collapse
|
13
|
Hamada N. What are the intracellular targets and intratissue target cells for radiation effects? Radiat Res 2014; 181:9-20. [PMID: 24369848 DOI: 10.1667/rr13505.1] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Exactly a century after Röntgen's discovery of X rays, I entered a university to major in radiological sciences. At that time, I felt that, despite extensive use and indispensable roles of ionizing radiation in medicine and industry, many fascinating questions have yet to be answered concerning its biological mechanisms of action, and thus I decided to get into the field of radiation research. Fifteen years have passed since I started radiobiological studies in 1998, during which time various basic tenets I initially learned in my late teens and early twenties have been challenged by recent observations. Of these, this brief overview particularly focuses on the following five different albeit non mutually exclusive questions: (i) "Is nuclear DNA the only intracellular target for radiation effects?"; (ii) "What is the significance of delayed cell death in clonogenic survival?"; (iii) "Does an irradiated cell become a cancer cell?"; (iv) "Are cataracts tissue reactions?"; and (v) "Why is high-LET radiation biologically effective?".
Collapse
Affiliation(s)
- Nobuyuki Hamada
- Radiation Safety Research Center, Nuclear Technology Research Laboratory, Central Research Institute of Electric Power Industry (CRIEPI), Tokyo, Japan
| |
Collapse
|
14
|
Held KD. Summary: achievements, critical issues, and thoughts on the future. HEALTH PHYSICS 2012; 103:681-4. [PMID: 23032899 PMCID: PMC3464434 DOI: 10.1097/hp.0b013e318264b2f5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The number of individuals exposed to particle radiations in cancer treatment worldwide is increasing rapidly, and space agencies are developing plans for long duration, deep space missions in which humans could be exposed to significant levels of radiation from charged particles. Hence, the NCRP 47 th Annual Meeting on "Scientific and Policy Challenges of Particle Radiations in Medical Therapy and Space Missions" was a timely opportunity to showcase the current scientific knowledge regarding charged particles, enhance cross-fertilization between the oncology and space scientific communities, and identify common needs and challenges to both communities as well as ways to address those challenges. This issue of Health Physics contains papers from talks presented at that meeting and highlights provocative questions and the ample opportunities for synergism between space and particle-therapy research to further understanding of the biological impacts of particle radiations.
Collapse
Affiliation(s)
- Kathryn D Held
- Department of Radiation Oncology, Massachusetts General Hospital/Harvard Medical School, Boston, MA 02114, USA.
| |
Collapse
|