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Katsube T, Wang B, Tanaka K, Ninomiya Y, Hirakawa H, Liu C, Maruyama K, Vares G, Liu Q, Murakami M, Nakajima T, Fujimori A, Nenoi M. Fluorescence in situ hybridization analysis of chromosomal aberrations in mouse splenocytes at one- and two-months after total body exposure to iron-56 (Fe) ion particles or X-rays. MUTATION RESEARCH. GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2022; 882:503548. [PMID: 36155141 DOI: 10.1016/j.mrgentox.2022.503548] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Revised: 08/25/2022] [Accepted: 09/08/2022] [Indexed: 06/16/2023]
Abstract
High atomic number and energy (HZE) particles such as iron-56 (Fe) ions are a major contributor to health risks in long-term manned space exploration. The aim of this study is to understand radiation-induced differential genotoxic effects between HZE particles and low linear energy transfer (LET) photons. C57BL/6J Jms female mice of 8 weeks old were exposed to total body irradiation of accelerated Fe-particles with a dose ranging from 0.1 to 3.0 Gy or of X-rays with a dose ranging from 0.1 to 5.0 Gy. Chromosomal aberrations (CAs) in splenocytes were examined by fluorescence in situ hybridization at 1- and 2-months after exposure. Clonal expansions of cells with CAs were found to be induced only by X-rays but not by Fe-particles. Dose-dependent increase in the frequencies of stable-type CAs was observed at 1- as well as 2-months after exposure to both radiation types. The frequencies of stable-type CAs in average were much higher in mice exposed to X-rays than those to Fe-particles and did not change significantly between 1- and 2-months after exposure to both radiation types. On the other hand, the frequencies of unstable-type CAs induced by X-rays and Fe-particles were not much different, and they appeared to decrease with time from 1- to 2-months after exposure. These results suggested that larger fraction of stable-type CAs induced by Fe-particles might be non-transmissible than those by X-rays because of some associating lethal alterations on themselves or on other chromosomes in the same cells and that these cells might be removed by 1-month after Fe-TBI. We also demonstrated that exposure to Fe-particles induced insertions at relatively higher frequency to other stable-type CAs than X-rays. Our findings suggest that insertions can be used as indicators of past exposure to high-LET particle radiation.
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Affiliation(s)
- Takanori Katsube
- National Institute of Radiological Sciences, National Institutes for Quantum Science and Technology, Chiba 263-8555, Japan.
| | - Bing Wang
- National Institute of Radiological Sciences, National Institutes for Quantum Science and Technology, Chiba 263-8555, Japan
| | - Kaoru Tanaka
- National Institute of Radiological Sciences, National Institutes for Quantum Science and Technology, Chiba 263-8555, Japan
| | - Yasuharu Ninomiya
- National Institute of Radiological Sciences, National Institutes for Quantum Science and Technology, Chiba 263-8555, Japan
| | - Hirokazu Hirakawa
- Institute for Quantum Medical Science, National Institutes for Quantum Science and Technology, Chiba 263-8555, Japan
| | - Cuihua Liu
- Institute for Quantum Medical Science, National Institutes for Quantum Science and Technology, Chiba 263-8555, Japan
| | - Kouichi Maruyama
- National Institute of Radiological Sciences, National Institutes for Quantum Science and Technology, Chiba 263-8555, Japan
| | - Guillaume Vares
- Experimental Radiotoxicology and Radiobiology Laboratory, Institute for Radioprotection and Nuclear Safety, B.P. 17 - 92262 Fontenay-aux-Roses Cedex, France
| | - Qiang Liu
- Institute of Radiation Medicine, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin 300192, PR China
| | - Masahiro Murakami
- National Institute of Radiological Sciences, National Institutes for Quantum Science and Technology, Chiba 263-8555, Japan
| | - Tetsuo Nakajima
- National Institute of Radiological Sciences, National Institutes for Quantum Science and Technology, Chiba 263-8555, Japan
| | - Akira Fujimori
- Institute for Quantum Medical Science, National Institutes for Quantum Science and Technology, Chiba 263-8555, Japan
| | - Mitsuru Nenoi
- Human Resources Development Center, National Institutes for Quantum Science and Technology, Chiba 263-8555, Japan.
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Nakajima T, Ninomiya Y, Unno K, Morioka T, Nishimura M, Kakinuma S. Impacts of psychological stress on high dose-rate radiation acute effects in a mouse experimental model. JOURNAL OF RADIATION RESEARCH 2022; 63:602-608. [PMID: 35726341 PMCID: PMC9303612 DOI: 10.1093/jrr/rrac028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Revised: 01/23/2022] [Indexed: 06/15/2023]
Abstract
Psychological stress affects health. Radiation workers in the medical field or astronauts living in space have possible risks of exposure to radiation, and psychological stress is considered to be easily induced in them due to activities performed in small areas or stress conditions. The impact of psychological stress on the effects of radiation was evaluated in senescence-accelerated mouse prone 10 (SAMP10) mice and ddY mice using a confrontational housing model, which makes dominant and subordinate mice in a cage live together without severe quarrel. Mice of ddY and SAMP10 have been previously demonstrated to be influenced in terms of acute and late effects, respectively, under psychological stress by this model. In SAMP10 mice, irradiation with 4 Gy induced the death of irradiated mice under psychological stress. In ddY mice, irradiation with 5 Gy X-rays alone had almost no effect on the mouse survival, but irradiation in conditions of psychological stress promoted acute death of irradiated mice. In addition, hypocellular bone marrow was also observed histopathologically in irradiated ddY mice under stress. Psychological stress may promote damage caused by radiation through modulation of radio-sensitivity in bone marrow in mice. This model would be useful for evaluation of modulation of radiation-induced various effects by psychological stress.
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Affiliation(s)
- Tetsuo Nakajima
- Corresponding author. Department of Radiation Effects Research, National Institute of Radiological Sciences, QST, Chibashi, 263-8555 Japan. Tel/Fax +81-43-206-3086/+81-43-255-6497 E-mail:
| | - Yasuharu Ninomiya
- Department of Radiation Effects Research, National Institute of Radiological Sciences, QST, Chiba-shi, 263-8555 Japan
| | - Keiko Unno
- Tea Science Center, University of Shizuoka, Shizuoka 422-8526, Japan
| | - Takamitsu Morioka
- Department of Radiation Effects Research, National Institute of Radiological Sciences, QST, Chiba-shi, 263-8555 Japan
| | - Mayumi Nishimura
- Department of Radiation Effects Research, National Institute of Radiological Sciences, QST, Chiba-shi, 263-8555 Japan
| | - Shizuko Kakinuma
- Department of Radiation Effects Research, National Institute of Radiological Sciences, QST, Chiba-shi, 263-8555 Japan
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Enhanced Effects of Chronic Restraint-Induced Psychological Stress on Total Body Fe-Irradiation-Induced Hematopoietic Toxicity in Trp53-Heterozygous Mice. Life (Basel) 2022; 12:life12040565. [PMID: 35455056 PMCID: PMC9025703 DOI: 10.3390/life12040565] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 03/28/2022] [Accepted: 04/05/2022] [Indexed: 11/25/2022] Open
Abstract
Humans are exposed to both psychological stress (PS) and radiation in some scenarios such as manned deep-space missions. It is of great concern to verify possible enhanced deleterious effects from such concurrent exposure. Pioneer studies showed that chronic restraint-induced PS (CRIPS) could attenuate Trp53 functions and increase gamma-ray-induced carcinogenesis in Trp53-heterozygous mice while CRIPS did not significantly modify the effects on X-ray-induced hematopoietic toxicity in Trp53 wild-type mice. As high-linear energy transfer (LET) radiation is the most important component of space radiation in causing biological effects, we further investigated the effects of CRIPS on high-LET iron-particle radiation (Fe)-induced hematopoietic toxicity in Trp53-heterozygous mice. The results showed that CRIPS alone could hardly induce significant alteration in hematological parameters (peripheral hemogram and micronucleated erythrocytes in bone marrow) while concurrent exposure caused elevated genotoxicity measured as micronucleus incidence in erythrocytes. Particularly, exposure to either CRISP or Fe-particle radiation at a low dose (0.1 Gy) did not induce a marked increase in the micronucleus incidence; however, concurrent exposure caused a significantly higher increase in the micronucleus incidence. These findings indicated that CRIPS could enhance the deleterious effects of high-LET radiation, particularly at a low dose, on the hematopoietic toxicity in Trp53-heterozygous mice.
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Katsube T, Wang B, Tanaka K, Ninomiya Y, Hirakawa H, Liu C, Maruyama K, Vares G, Liu Q, Kito S, Nakajima T, Fujimori A, Nenoi M. Synergistic Effects of Chronic Restraint-Induced Stress and Low-Dose 56Fe-particle Irradiation on Induction of Chromosomal Aberrations in Trp53-Heterozygous Mice. Radiat Res 2021; 196:100-112. [PMID: 33901294 DOI: 10.1667/rade-20-00218.1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Accepted: 03/26/2021] [Indexed: 11/03/2022]
Abstract
Astronauts can develop psychological stress (PS) during space flights due to the enclosed environment, microgravity, altered light-dark cycles, and risks of equipment failure or fatal mishaps. At the same time, they are exposed to cosmic rays including high atomic number and energy (HZE) particles such as iron-56 (Fe) ions. Psychological stress or radiation exposure can cause detrimental effects in humans. An earlier published pioneering study showed that chronic restraint-induced psychological stress (CRIPS) could attenuate Trp53 functions and increase carcinogenesis induced by low-linear energy transfer (LET) γ rays in Trp53-heterozygous (Trp53+/-) mice. To elucidate possible modification effects from CRIPS on high-LET HZE particle-induced health consequences, Trp53+/- mice were received both CRIPS and accelerated Fe ion irradiation. Six-week-old Trp53+/- C57BL/6N male mice were restrained 6 h per day for 28 consecutive days. On day 8, they received total-body Fe-particle irradiation (Fe-TBI, 0.1 or 2 Gy). Metaphase chromosome spreads prepared from splenocytes at the end of the 28-day restraint regimen were painted with the fluorescence in situ hybridization (FISH) probes for chromosomes 1 (green), 2 (red) and 3 (yellow). Induction of psychological stress in our experimental model was confirmed by increase in urinary corticosterone level on day 7 of restraint regimen. Regardless of Fe-TBI, CRIPS reduced splenocyte number per spleen at the end of the 28-day restraint regimen. At 2 Gy, Fe-TBI alone induced many aberrant chromosomes and no modifying effect was detected from CRIPS on induction of aberrant chromosomes. Notably, neither Fe-TBI at 0.1 Gy nor CRIPS alone induced any increase in the frequency of aberrant chromosomes, while simultaneous exposure resulted in a significant increase in the frequency of chromosomal exchanges. These findings clearly showed that CRIPS could enhance the frequency of chromosomal exchanges induced by Fe-TBI at a low dose of 0.1 Gy.
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Affiliation(s)
- Takanori Katsube
- National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba
| | - Bing Wang
- National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba
| | - Kaoru Tanaka
- National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba
| | - Yasuharu Ninomiya
- National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba
| | - Hirokazu Hirakawa
- National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba
| | - Cuihua Liu
- National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba
| | - Kouichi Maruyama
- Center for Advanced Radiation Emergency Medicine, National Institutes for Quantum and Radiological Science and Technology, Chiba 263-8555, Japan
| | - Guillaume Vares
- Okinawa Institute of Science and Technology Graduate University, Okinawa 904-0495, Japan
| | - Qiang Liu
- Institute of Radiation Medicine, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin 300192, PR China
| | - Seiji Kito
- Center for Animal Research and Education, Nagoya University, Nagoya 464-8601, Japan
| | - Tetsuo Nakajima
- National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba
| | - Akira Fujimori
- National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba
| | - Mitsuru Nenoi
- National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba
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Collett G, Craenen K, Young W, Gilhooly M, Anderson RM. The psychological consequences of (perceived) ionizing radiation exposure: a review on its role in radiation-induced cognitive dysfunction. Int J Radiat Biol 2020; 96:1104-1118. [PMID: 32716221 DOI: 10.1080/09553002.2020.1793017] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
PURPOSE Exposure to ionizing radiation following environmental contamination (e.g., the Chernobyl and Fukushima nuclear accidents), radiotherapy and diagnostics, occupational roles and space travel has been identified as a possible risk-factor for cognitive dysfunction. The deleterious effects of high doses (≥1.0 Gy) on cognitive functioning are fairly well-understood, while the consequences of low (≤0.1 Gy) and moderate doses (0.1-1.0 Gy) have been receiving more research interest over the past decade. In addition to any impact of actual exposure on cognitive functioning, the persistent psychological stress arising from perceived exposure, particularly following nuclear accidents, may itself impact cognitive functioning. In this review we offer a novel interdisciplinary stance on the cognitive impact of radiation exposure, considering psychological and epidemiological observations of different exposure scenarios such as atomic bombings, nuclear accidents, occupational and medical exposures while accounting for differences in dose, rate of exposure and exposure type. The purpose is to address the question that perceived radiation exposure - even where the actual absorbed dose is 0.0 Gy above background dose - can result in psychological stress, which could in turn lead to cognitive dysfunction. In addition, we highlight the interplay between the mechanisms of perceived exposure (i.e., stress) and actual exposure (i.e., radiation-induced cellular damage), in the generation of radiation-induced cognitive dysfunction. In all, we offer a comprehensive and objective review addressing the potential for cognitive defects in the context of low- and moderate-dose IR exposures. CONCLUSIONS Overall the evidence shows prenatal exposure to low and moderate doses to be detrimental to brain development and subsequent cognitive functioning, however the evidence for adolescent and adult low- and moderate-dose exposure remains uncertain. The persistent psychological stress following accidental exposure to low-doses in adulthood may pose a greater threat to our cognitive functioning. Indeed, the psychological implications for instructed cohorts (e.g., astronauts and radiotherapy patients) is less clear and warrants further investigation. Nonetheless, the psychosocial consequences of low- and moderate-dose exposure must be carefully considered when evaluating radiation effects on cognitive functioning, and to avoid unnecessary harm when planning public health response strategies.
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Affiliation(s)
- George Collett
- Centre for Health Effects of Radiological and Chemical Agents, Institute of Environment, Health and Societies, College of Health and Life Sciences, Brunel University London, Uxbridge, UK
| | - Kai Craenen
- Centre for Health Effects of Radiological and Chemical Agents, Institute of Environment, Health and Societies, College of Health and Life Sciences, Brunel University London, Uxbridge, UK
| | - William Young
- Centre for Health Effects of Radiological and Chemical Agents, Institute of Environment, Health and Societies, College of Health and Life Sciences, Brunel University London, Uxbridge, UK
| | - Mary Gilhooly
- Centre for Health Effects of Radiological and Chemical Agents, Institute of Environment, Health and Societies, College of Health and Life Sciences, Brunel University London, Uxbridge, UK
| | - Rhona M Anderson
- Centre for Health Effects of Radiological and Chemical Agents, Institute of Environment, Health and Societies, College of Health and Life Sciences, Brunel University London, Uxbridge, UK
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Furukawa S, Nagamatsu A, Nenoi M, Fujimori A, Kakinuma S, Katsube T, Wang B, Tsuruoka C, Shirai T, Nakamura AJ, Sakaue-Sawano A, Miyawaki A, Harada H, Kobayashi M, Kobayashi J, Kunieda T, Funayama T, Suzuki M, Miyamoto T, Hidema J, Yoshida Y, Takahashi A. Space Radiation Biology for "Living in Space". BIOMED RESEARCH INTERNATIONAL 2020; 2020:4703286. [PMID: 32337251 PMCID: PMC7168699 DOI: 10.1155/2020/4703286] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Accepted: 03/13/2020] [Indexed: 12/16/2022]
Abstract
Space travel has advanced significantly over the last six decades with astronauts spending up to 6 months at the International Space Station. Nonetheless, the living environment while in outer space is extremely challenging to astronauts. In particular, exposure to space radiation represents a serious potential long-term threat to the health of astronauts because the amount of radiation exposure accumulates during their time in space. Therefore, health risks associated with exposure to space radiation are an important topic in space travel, and characterizing space radiation in detail is essential for improving the safety of space missions. In the first part of this review, we provide an overview of the space radiation environment and briefly present current and future endeavors that monitor different space radiation environments. We then present research evaluating adverse biological effects caused by exposure to various space radiation environments and how these can be reduced. We especially consider the deleterious effects on cellular DNA and how cells activate DNA repair mechanisms. The latest technologies being developed, e.g., a fluorescent ubiquitination-based cell cycle indicator, to measure real-time cell cycle progression and DNA damage caused by exposure to ultraviolet radiation are presented. Progress in examining the combined effects of microgravity and radiation to animals and plants are summarized, and our current understanding of the relationship between psychological stress and radiation is presented. Finally, we provide details about protective agents and the study of organisms that are highly resistant to radiation and how their biological mechanisms may aid developing novel technologies that alleviate biological damage caused by radiation. Future research that furthers our understanding of the effects of space radiation on human health will facilitate risk-mitigating strategies to enable long-term space and planetary exploration.
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Affiliation(s)
- Satoshi Furukawa
- Japan Aerospace Exploration Agency, 2-1-1 Sengen, Tsukuba, Ibaraki 305-8505, Japan
| | - Aiko Nagamatsu
- Japan Aerospace Exploration Agency, 2-1-1 Sengen, Tsukuba, Ibaraki 305-8505, Japan
| | - Mitsuru Nenoi
- National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology (QST), 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan
| | - Akira Fujimori
- National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology (QST), 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan
| | - Shizuko Kakinuma
- National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology (QST), 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan
| | - Takanori Katsube
- National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology (QST), 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan
| | - Bing Wang
- National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology (QST), 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan
| | - Chizuru Tsuruoka
- National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology (QST), 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan
| | - Toshiyuki Shirai
- National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology (QST), 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan
| | - Asako J. Nakamura
- Department of Biological Sciences, College of Science, Ibaraki University, 2-1-1, Bunkyo, Mito, Ibaraki 310-8512, Japan
| | - Asako Sakaue-Sawano
- Lab for Cell Function and Dynamics, CBS, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Atsushi Miyawaki
- Lab for Cell Function and Dynamics, CBS, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Hiroshi Harada
- Radiation Biology Center, Graduate School of Biostudies, Kyoto University, Yoshida Konoe-cho, Sakyo-ku, Kyoto 606-8501, Japan
| | - Minoru Kobayashi
- Radiation Biology Center, Graduate School of Biostudies, Kyoto University, Yoshida Konoe-cho, Sakyo-ku, Kyoto 606-8501, Japan
| | - Junya Kobayashi
- Radiation Biology Center, Graduate School of Biostudies, Kyoto University, Yoshida Konoe-cho, Sakyo-ku, Kyoto 606-8501, Japan
| | - Takekazu Kunieda
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Tomoo Funayama
- Takasaki Advanced Radiation Research Institute, QST, 1233 Watanuki-machi, Takasaki, Gunma 370-1292, Japan
| | - Michiyo Suzuki
- Takasaki Advanced Radiation Research Institute, QST, 1233 Watanuki-machi, Takasaki, Gunma 370-1292, Japan
| | - Tatsuo Miyamoto
- Research Institute for Radiation Biology and Medicine, Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima 734-8553, Japan
| | - Jun Hidema
- Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577, Japan
- Division for the Establishment of Frontier Sciences of the Organization for Advanced Studies, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577, Japan
| | - Yukari Yoshida
- Gunma University Heavy Ion Medical Center, 3-39-22 Showa-machi, Maebashi, Gunma 371-8511, Japan
| | - Akihisa Takahashi
- Gunma University Heavy Ion Medical Center, 3-39-22 Showa-machi, Maebashi, Gunma 371-8511, Japan
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Fabbrizi MR, Warshowsky KE, Zobel CL, Hallahan DE, Sharma GG. Molecular and epigenetic regulatory mechanisms of normal stem cell radiosensitivity. Cell Death Discov 2018; 4:117. [PMID: 30588339 PMCID: PMC6299079 DOI: 10.1038/s41420-018-0132-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Revised: 11/01/2018] [Accepted: 11/20/2018] [Indexed: 12/14/2022] Open
Abstract
Ionizing radiation (IR) therapy is a major cancer treatment modality and an indispensable auxiliary treatment for primary and metastatic cancers, but invariably results in debilitating organ dysfunctions. IR-induced depletion of neural stem/progenitor cells in the subgranular zone of the dentate gyrus in the hippocampus where neurogenesis occurs is considered largely responsible for deficiencies such as learning, memory, and spatial information processing in patients subjected to cranial irradiation. Similarly, IR therapy-induced intestinal injuries such as diarrhea and malabsorption are common side effects in patients with gastrointestinal tumors and are believed to be caused by intestinal stem cell drop out. Hematopoietic stem cell transplantation is currently used to reinstate blood production in leukemia patients and pre-clinical treatments show promising results in other organs such as the skin and kidney, but ethical issues and logistic problems make this route difficult to follow. An alternative way to restore the injured tissue is to preserve the stem cell pool located in that specific tissue/organ niche, but stem cell response to ionizing radiation is inadequately understood at the molecular mechanistic level. Although embryonic and fetal hypersensity to IR has been very well known for many decades, research on embryonic stem cell models in culture concerning molecular mechanisms have been largely inconclusive and often in contradiction of the in vivo observations. This review will summarize the latest discoveries on stem cell radiosensitivity, highlighting the possible molecular and epigenetic mechanism(s) involved in DNA damage response and programmed cell death after ionizing radiation therapy specific to normal stem cells. Finally, we will analyze the possible contribution of stem cell-specific chromatin's epigenetic constitution in promoting normal stem cell radiosensitivity.
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Affiliation(s)
- Maria Rita Fabbrizi
- Cancer Biology Division, Department of Radiation Oncology, Washington University School of Medicine, 4511 Forest Park, Saint Louis, MO 63108 USA
| | - Kacie E. Warshowsky
- Cancer Biology Division, Department of Radiation Oncology, Washington University School of Medicine, 4511 Forest Park, Saint Louis, MO 63108 USA
| | - Cheri L. Zobel
- Cancer Biology Division, Department of Radiation Oncology, Washington University School of Medicine, 4511 Forest Park, Saint Louis, MO 63108 USA
| | - Dennis E. Hallahan
- Cancer Biology Division, Department of Radiation Oncology, Washington University School of Medicine, 4511 Forest Park, Saint Louis, MO 63108 USA
- Siteman Cancer Center, Washington University School of Medicine, Saint Louis, MO 63108 USA
| | - Girdhar G. Sharma
- Cancer Biology Division, Department of Radiation Oncology, Washington University School of Medicine, 4511 Forest Park, Saint Louis, MO 63108 USA
- Siteman Cancer Center, Washington University School of Medicine, Saint Louis, MO 63108 USA
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