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Ibragimova M, Kussainova A, Aripova A, Bersimbaev R, Bulgakova O. The Molecular Mechanisms in Senescent Cells Induced by Natural Aging and Ionizing Radiation. Cells 2024; 13:550. [PMID: 38534394 DOI: 10.3390/cells13060550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2024] [Revised: 03/17/2024] [Accepted: 03/19/2024] [Indexed: 03/28/2024] Open
Abstract
This review discusses the relationship between cellular senescence and radiation exposure. Given the wide range of ionizing radiation sources encountered by people in professional and medical spheres, as well as the influence of natural background radiation, the question of the effect of radiation on biological processes, particularly on aging processes, remains highly relevant. The parallel relationship between natural and radiation-induced cellular senescence reveals the common aspects underlying these processes. Based on recent scientific data, the key points of the effects of ionizing radiation on cellular processes associated with aging, such as genome instability, mitochondrial dysfunction, altered expression of miRNAs, epigenetic profile, and manifestation of the senescence-associated secretory phenotype (SASP), are discussed. Unraveling the molecular mechanisms of cellular senescence can make a valuable contribution to the understanding of the molecular genetic basis of age-associated diseases in the context of environmental exposure.
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Affiliation(s)
- Milana Ibragimova
- Department of General Biology and Genomics, Institute of Cell Biology and Biotechnology, L.N. Gumilyov Eurasian National University, Astana 010008, Kazakhstan
| | - Assiya Kussainova
- Department of General Biology and Genomics, Institute of Cell Biology and Biotechnology, L.N. Gumilyov Eurasian National University, Astana 010008, Kazakhstan
- Department of Health Sciences, University of Genova, Via Pastore 1, 16132 Genoa, Italy
| | - Akmaral Aripova
- Department of General Biology and Genomics, Institute of Cell Biology and Biotechnology, L.N. Gumilyov Eurasian National University, Astana 010008, Kazakhstan
| | - Rakhmetkazhi Bersimbaev
- Department of General Biology and Genomics, Institute of Cell Biology and Biotechnology, L.N. Gumilyov Eurasian National University, Astana 010008, Kazakhstan
| | - Olga Bulgakova
- Department of General Biology and Genomics, Institute of Cell Biology and Biotechnology, L.N. Gumilyov Eurasian National University, Astana 010008, Kazakhstan
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Kumar K, Moon BH, Datta K, Fornace AJ, Suman S. Simulated galactic cosmic radiation (GCR)-induced expression of Spp1 coincide with mammary ductal cell proliferation and preneoplastic changes in Apc Min/+ mouse. LIFE SCIENCES IN SPACE RESEARCH 2023; 36:116-122. [PMID: 36682820 DOI: 10.1016/j.lssr.2022.09.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 08/18/2022] [Accepted: 09/16/2022] [Indexed: 06/17/2023]
Abstract
Female astronauts inevitably exposed to galactic cosmic radiation (GCR) are considered at a greater risk for mammary cancer development. The purpose of this study is to assess the status of mammary cancer-associated preneoplasia markers after GCR and γ-ray irradiation using a mouse model of human mammary cancer. Female ApcMin/+ mice were irradiated to 50 cGy of either γ-ray (137Cs) or full-spectrum simulated galactic cosmic radiation (GCR) (33-beam), and at 110 - 120 days post-irradiation mice were euthanized, and normal-appearing mammary tissues were analyzed for histological and molecular markers of preneoplasia. Whole-mount staining, hematoxylin and eosin-based histological assessment, and Cyclin D1 immunohistochemistry (IHC) were performed to analyze ductal outgrowth and cell proliferation. Additionally, mRNA expression of known mammary preneoplasia markers (Muc1, Exo1, Foxm1, Depdc1a, Nusap1, Spp1, and Rrm2) was analyzed using qPCR, and their respective protein expression was validated using immunohistochemistry. A significant increase in ductal outgrowth and cell proliferation in mammary tissues of GCR-irradiated mice was noted which indicates a higher risk of mammary cancer, relative to γ-rays. Increased mRNA and protein expression of Spp1 was observed in the GCR group, relative to γ-rays. This study demonstrates the plausibility of Spp1 as a preneoplasia marker in the early detection of mammary cancer after space radiation exposure.
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Affiliation(s)
- Kamendra Kumar
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, DC 20057, United States of America
| | - Bo-Hyun Moon
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, DC 20057, United States of America
| | - Kamal Datta
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, DC 20057, United States of America
| | - Albert J Fornace
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, DC 20057, United States of America; Department of Biochemistry and Molecular & Cellular Biology, Georgetown University Medical Center, Washington, DC 20057, United States of America
| | - Shubhankar Suman
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, DC 20057, United States of America.
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Kudo KI, Tsuyama N, Nagata K, Imaoka T, Iizuka D, Sugai-Takahashi M, Muramatsu M, Sakai A. ΔNp63α transcriptionally represses p53 target genes involved in the radiation-induced DNA damage response : ΔNp63α may cause genomic instability in epithelial stem cells. Radiat Oncol 2022; 17:183. [PMID: 36380314 PMCID: PMC9667649 DOI: 10.1186/s13014-022-02139-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Accepted: 10/05/2022] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND The DNA damage response (DDR) is a mechanism that protects cells against radiation-induced oxidative DNA damage by causing cell cycle arrest and apoptosis. TP63 is a member of the tumour suppressor TP53 gene family, and ΔNp63α, a TP63 splicing variant, is constitutively expressed in the stem cell-containing basal layer of stratified epithelial tissues, including the mammary gland, where it plays a critical role in stemness and tissue development. ΔNp63α has been reported to transcriptionally inhibit the tumour suppression protein p53. This p53-repressive activity may cause genomic instability in epithelial stem cells exposed to radiation. In this study, we analysed the inhibitory effect of ΔNp63α on radiation-induced DDR. METHODS To elucidate the role of the p53-repressive effect of ΔNp63α in radiation response, we performed a p63-siRNA knockdown experiment using human mammary epithelial cells (HMECs) expressing ΔNp63α and then performed ectopic and entopic expression experiments using human induced pluripotent stem cells (hiPSCs). After irradiation, the expression of DDR-related genes and proteins in ΔNp63α-expressing and control cells was analysed by RT-qPCR, Western blotting, and flow cytometry. RESULTS The mRNA/protein expression levels of BAX and p21 were significantly increased in p63-siRNA-treated HMECs (sip63) after X-ray irradiation (4 Gy, 0.7 Gy/min) but not in scramble-siRNA treated HMECs (scr). Transcriptomic analysis showed decreased RNA expression of cell cycle-related genes and increased expression of programmed cell death-related genes in sip63 cells compared to scr cells. Furthermore, flow cytometric analysis revealed an increase in apoptotic cells and a decrease in 5-ethynyl-2´-deoxyuridine uptake in sip63 cells compared to scr cells. On the other hand, both the ectopic and entopic expression of ΔNp63α in apoptosis-sensitive hiPSCs reduced the expression levels of BAX after irradiation and significantly decreased the number of apoptotic cells induced by radiation. CONCLUSION Taken together, these results indicate that ΔNp63α represses p53-related radiation-induced DDR, thereby potentially causing genomic instability in epithelial stem cells.
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Affiliation(s)
- Ken-Ichi Kudo
- Department of Radiation Life Sciences, Fukushima Medical University School of Medicine, Fukushima, Japan.
| | - Naohiro Tsuyama
- Department of Radiation Life Sciences, Fukushima Medical University School of Medicine, Fukushima, Japan
| | - Kento Nagata
- Department of Radiation Effects Research, National Institute of Radiological Sciences, National Institutes for Quantum Science and Technology, Chiba, Japan
| | - Tatsuhiko Imaoka
- Department of Radiation Effects Research, National Institute of Radiological Sciences, National Institutes for Quantum Science and Technology, Chiba, Japan
| | - Daisuke Iizuka
- Department of Radiation Effects Research, National Institute of Radiological Sciences, National Institutes for Quantum Science and Technology, Chiba, Japan
| | - Misaki Sugai-Takahashi
- Department of Radiation Life Sciences, Fukushima Medical University School of Medicine, Fukushima, Japan
| | - Moe Muramatsu
- Department of Diagnostic Pathology, Fukushima Medical University School of Medicine, Fukushima, Japan
| | - Akira Sakai
- Department of Radiation Life Sciences, Fukushima Medical University School of Medicine, Fukushima, Japan
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Imaoka T, Nishimura M, Daino K, Hosoki A, Kudo KI, Iizuka D, Nagata K, Takabatake M, Nishimura Y, Kokubo T, Morioka T, Doi K, Shimada Y, Kakinuma S. DOSE-RATE EFFECT OF RADIATION ON RAT MAMMARY CARCINOGENESIS AND AN EMERGING ROLE FOR STEM CELL BIOLOGY. RADIATION PROTECTION DOSIMETRY 2022; 198:1036-1046. [PMID: 36083756 DOI: 10.1093/rpd/ncac050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 03/03/2022] [Accepted: 03/20/2021] [Indexed: 06/15/2023]
Abstract
The uncertain cancer risk of protracted radiation exposure at low dose rates is an important issue in radiological protection. Tissue stem/progenitor cells are a supposed origin of cancer and may contribute to the dose-rate effect on carcinogenesis. The authors have shown that female rats subjected to continuous whole body γ irradiation as juveniles or young adults have a notably reduced incidence of mammary cancer as compared with those irradiated acutely. Experiments using the mammosphere formation assay suggested the presence of radioresistant progenitor cells. Cell sorting indicated that basal progenitor cells in rat mammary gland were more resistant than luminal progenitors to killing by acute radiation, especially at high doses. Thus, the evidence indicates a cell-type-dependent inactivation of mammary cells that manifests only at high acute doses, implying a link to the observed dose-rate effect on carcinogenesis.
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Affiliation(s)
- Tatsuhiko Imaoka
- Department of Radiation Effects Research, National Institute of Radiological Sciences, National Institutes for Quantum Science and Technology, Chiba 263-8555, Japan
| | - Mayumi Nishimura
- Department of Radiation Effects Research, National Institute of Radiological Sciences, National Institutes for Quantum Science and Technology, Chiba 263-8555, Japan
| | - Kazuhiro Daino
- Department of Radiation Effects Research, National Institute of Radiological Sciences, National Institutes for Quantum Science and Technology, Chiba 263-8555, Japan
| | - Ayaka Hosoki
- Department of Radiation Effects Research, National Institute of Radiological Sciences, National Institutes for Quantum Science and Technology, Chiba 263-8555, Japan
| | - Ken-Ichi Kudo
- Department of Radiation Effects Research, National Institute of Radiological Sciences, National Institutes for Quantum Science and Technology, Chiba 263-8555, Japan
- Department of Radiation Life Sciences, School of Medicine, Fukushima Medical University, Fukushima 960-1247, Japan
| | - Daisuke Iizuka
- Department of Radiation Effects Research, National Institute of Radiological Sciences, National Institutes for Quantum Science and Technology, Chiba 263-8555, Japan
| | - Kento Nagata
- Department of Radiation Effects Research, National Institute of Radiological Sciences, National Institutes for Quantum Science and Technology, Chiba 263-8555, Japan
| | - Masaru Takabatake
- Department of Radiation Effects Research, National Institute of Radiological Sciences, National Institutes for Quantum Science and Technology, Chiba 263-8555, Japan
- Department of Radiological Sciences, Graduate School of Human Health Sciences, Tokyo Metropolitan University, Tokyo 116-8551, Japan
| | - Yukiko Nishimura
- Department of Radiation Effects Research, National Institute of Radiological Sciences, National Institutes for Quantum Science and Technology, Chiba 263-8555, Japan
| | - Toshiaki Kokubo
- Laboratory Animal and Genome Sciences Section, National Institutes for Quantum Science and Technology, Chiba 263-8555, Japan
| | - Takamitsu Morioka
- Department of Radiation Effects Research, National Institute of Radiological Sciences, National Institutes for Quantum Science and Technology, Chiba 263-8555, Japan
| | - Kazutaka Doi
- Department of Radiation Regulatory Science Research, National Institute of Radiological Sciences, National Institutes for Quantum Science and Technology, Chiba 263-8555, Japan
| | - Yoshiya Shimada
- Department of Radiation Effects Research, National Institute of Radiological Sciences, National Institutes for Quantum Science and Technology, Chiba 263-8555, Japan
- Institute for Environmental Sciences, Aomori 039-3212, Japan
| | - Shizuko Kakinuma
- Department of Radiation Effects Research, National Institute of Radiological Sciences, National Institutes for Quantum Science and Technology, Chiba 263-8555, Japan
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5
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Cucinotta FA. Flying without a Net: Space Radiation Cancer Risk Predictions without a Gamma-ray Basis. Int J Mol Sci 2022; 23:4324. [PMID: 35457139 PMCID: PMC9029417 DOI: 10.3390/ijms23084324] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Revised: 04/06/2022] [Accepted: 04/12/2022] [Indexed: 11/24/2022] Open
Abstract
The biological effects of high linear energy transfer (LET) radiation show both a qualitative and quantitative difference when compared to low-LET radiation. However, models used to estimate risks ignore qualitative differences and involve extensive use of gamma-ray data, including low-LET radiation epidemiology, quality factors (QF), and dose and dose-rate effectiveness factors (DDREF). We consider a risk prediction that avoids gamma-ray data by formulating a track structure model of excess relative risk (ERR) with parameters estimated from animal studies using high-LET radiation. The ERR model is applied with U.S. population cancer data to predict lifetime risks to astronauts. Results for male liver and female breast cancer risk show that the ERR model agrees fairly well with estimates of a QF model on non-targeted effects (NTE) and is about 2-fold higher than the QF model that ignores NTE. For male or female lung cancer risk, the ERR model predicts about a 3-fold and more than 7-fold lower risk compared to the QF models with or without NTE, respectively. We suggest a relative risk approach coupled with improved models of tissue-specific cancers should be pursued to reduce uncertainties in space radiation risk projections. This approach would avoid low-LET uncertainties, while including qualitive effects specific to high-LET radiation.
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Affiliation(s)
- Francis A Cucinotta
- Department of Health Physics and Diagnostic Sciences, University of Nevada Las Vegas, Las Vegas, NV 89154, USA
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6
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Al-Jumayli M, Brown SL, Chetty IJ, Extermann M, Movsas B. The Biological Process of Aging and the Impact of Ionizing Radiation. Semin Radiat Oncol 2022; 32:172-178. [DOI: 10.1016/j.semradonc.2021.11.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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7
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Tsuruoka C, Kaminishi M, Shinagawa M, Shang Y, Amasaki Y, Shimada Y, Kakinuma S. High Relative Biological Effectiveness of 2 MeV Fast Neutrons for Induction of Medulloblastoma in Ptch1+/- Mice with Radiation-specific Deletion on Chromosome 13. Radiat Res 2021; 196:225-234. [PMID: 34046685 DOI: 10.1667/rade-20-00025.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Accepted: 05/06/2021] [Indexed: 11/03/2022]
Abstract
Neutron radiation, a high-linear energy transfer radiation, has a high relative biological effectiveness (RBE) for various end points. The age at exposure is an important modifier of the effects of radiation, including carcinogenesis, with infants being generally more radiosensitive. Ptch1+/- mice offer a unique experimental system for assessing radiation carcinogenesis. Spontaneous development of medulloblastoma tumors occurs in nonirradiated animals that lose their Ptch1+ allele, most frequently by a loss of heterozygosity (LOH) of chromosome 13 via recombination or non-disjunction (referred to as S-type tumors). In contrast, tumors occur in irradiated Ptch1+/- mice as a result of chromosome 13 LOH with an interstitial deletion (R-type), making spontaneous and radiation-induced tumors discernible. To elucidate the influence of age on the effect of fast neutrons, we irradiated Ptch1+/- mice with neutrons (mean energy, ∼2 MeV) or γ rays on embryonic day (E)14 and E17 and on postnatal day (P)1, 4 or 10 and classified the resulting medulloblastomas based on chromosome 13 aberrations. Instead of LOH, some tumors harbored mutations in their Ptch1+ gene via a nonirradiation-associated mechanism such as duplication, insertion, base substitution or deletion with microhomology-mediated end joining; thus, these tumors were classified as S-type. The RBE regarding the induction of R-type tumors was 12.9 (8.6, 17.2), 9.6 (6.9, 12.3), 21.5 (17.2, 25.8), and 7.1 (4.7, 9.5) (mean and 95% confidence interval) for mice irradiated on E14, E17, P1 and P4, respectively, with the highest value seen during the most active development of the tissue and P10 being completely resistant. These results indicate that the developmental stage at exposure of the tissue influences the RBE of neutrons.
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Affiliation(s)
- Chizuru Tsuruoka
- Department of Radiation Effects Research, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Mutsumi Kaminishi
- Department of Radiation Effects Research, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Mayumi Shinagawa
- Department of Radiation Effects Research, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Yi Shang
- Department of Radiation Effects Research, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Yoshiko Amasaki
- Department of Radiation Effects Research, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Yoshiya Shimada
- Institute for Environmental Science, Kamikita-gun, Aomori, Japan
| | - Shizuko Kakinuma
- Department of Radiation Effects Research, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
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8
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Applegate KE, Rühm W, Wojcik A, Bourguignon M, Brenner A, Hamasaki K, Imai T, Imaizumi M, Imaoka T, Kakinuma S, Kamada T, Nishimura N, Okonogi N, Ozasa K, Rübe CE, Sadakane A, Sakata R, Shimada Y, Yoshida K, Bouffler S. Individual response of humans to ionising radiation: governing factors and importance for radiological protection. RADIATION AND ENVIRONMENTAL BIOPHYSICS 2020; 59:185-209. [PMID: 32146555 DOI: 10.1007/s00411-020-00837-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Accepted: 02/26/2020] [Indexed: 05/23/2023]
Abstract
Tissue reactions and stochastic effects after exposure to ionising radiation are variable between individuals but the factors and mechanisms governing individual responses are not well understood. Individual responses can be measured at different levels of biological organization and using different endpoints following varying doses of radiation, including: cancers, non-cancer diseases and mortality in the whole organism; normal tissue reactions after exposures; and, cellular endpoints such as chromosomal damage and molecular alterations. There is no doubt that many factors influence the responses of people to radiation to different degrees. In addition to the obvious general factors of radiation quality, dose, dose rate and the tissue (sub)volume irradiated, recognized and potential determining factors include age, sex, life style (e.g., smoking, diet, possibly body mass index), environmental factors, genetics and epigenetics, stochastic distribution of cellular events, and systemic comorbidities such as diabetes or viral infections. Genetic factors are commonly thought to be a substantial contributor to individual response to radiation. Apart from a small number of rare monogenic diseases such as ataxia telangiectasia, the inheritance of an abnormally responsive phenotype among a population of healthy individuals does not follow a classical Mendelian inheritance pattern. Rather it is considered to be a multi-factorial, complex trait.
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Affiliation(s)
| | - W Rühm
- Helmholtz Center Munich, German Research Center for Environmental Health, Institute of Radiation Medicine, Neuherberg, Germany
| | - A Wojcik
- Centre for Radiation Protection Research, MBW Department, Stockholm University, Stockholm, Sweden
| | - M Bourguignon
- Department of Biophysics and Nuclear Medicine, University of Paris Saclay (UVSQ), Verseilles, France
| | - A Brenner
- Department of Epidemiology, Radiation Effects Research Foundation, Hiroshima, Japan
| | - K Hamasaki
- Department of Molecular Biosciences, Radiation Effects Research Foundation, Hiroshima, Japan
| | - T Imai
- National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Sciences and Technology, Chiba, Japan
| | - M Imaizumi
- Department of Nagasaki Clinical Studies, Radiation Effects Research Foundation, Nagasaki, Japan
| | - T Imaoka
- Department of Radiation Effects Research, National Institute of Radiological Sciences, National Institute for Quantum and Radiological Science and Technology, Chiba, Japan
| | - S Kakinuma
- Department of Radiation Effects Research, National Institute of Radiological Sciences, National Institute for Quantum and Radiological Science and Technology, Chiba, Japan
| | - T Kamada
- QST Hospital, National Institute of Radiological Sciences, National Institute for Quantum and Radiological Science and Technology, Chiba, Japan
| | - N Nishimura
- Department of Radiation Effects Research, National Institute of Radiological Sciences, National Institute for Quantum and Radiological Science and Technology, Chiba, Japan
| | - N Okonogi
- QST Hospital, National Institute of Radiological Sciences, National Institute for Quantum and Radiological Science and Technology, Chiba, Japan
| | - K Ozasa
- Department of Epidemiology, Radiation Effects Research Foundation, Hiroshima, Japan
| | - C E Rübe
- Department of Radiation Oncology, Saarland University Medical Center, Homburg/Saar, Germany
| | - A Sadakane
- Department of Epidemiology, Radiation Effects Research Foundation, Hiroshima, Japan
| | - R Sakata
- Department of Epidemiology, Radiation Effects Research Foundation, Hiroshima, Japan
| | - Y Shimada
- National Institute for Quantum and Radiological Science and Technology, Chiba, Japan
- Institute for Environmental Sciences, Aomori, Japan
| | - K Yoshida
- Immunology Laboratory, Department of Molecular Biosciences, Radiation Effects Research Foundation, Hiroshima, Japan
| | - S Bouffler
- Radiation Effects Department, Centre for Radiation, Chemical and Environmental Hazards, Public Health England, Chilto, Didcot, UK
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9
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Helm JS, Rudel RA. Adverse outcome pathways for ionizing radiation and breast cancer involve direct and indirect DNA damage, oxidative stress, inflammation, genomic instability, and interaction with hormonal regulation of the breast. Arch Toxicol 2020. [PMID: 32399610 DOI: 10.1007/s00204-020-02752-z)] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/05/2023]
Abstract
Knowledge about established breast carcinogens can support improved and modernized toxicological testing methods by identifying key mechanistic events. Ionizing radiation (IR) increases the risk of breast cancer, especially for women and for exposure at younger ages, and evidence overall supports a linear dose-response relationship. We used the Adverse Outcome Pathway (AOP) framework to outline and evaluate the evidence linking ionizing radiation with breast cancer from molecular initiating events to the adverse outcome through intermediate key events, creating a qualitative AOP. We identified key events based on review articles, searched PubMed for recent literature on key events and IR, and identified additional papers using references. We manually curated publications and evaluated data quality. Ionizing radiation directly and indirectly causes DNA damage and increases production of reactive oxygen and nitrogen species (RONS). RONS lead to DNA damage and epigenetic changes leading to mutations and genomic instability (GI). Proliferation amplifies the effects of DNA damage and mutations leading to the AO of breast cancer. Separately, RONS and DNA damage also increase inflammation. Inflammation contributes to direct and indirect effects (effects in cells not directly reached by IR) via positive feedback to RONS and DNA damage, and separately increases proliferation and breast cancer through pro-carcinogenic effects on cells and tissue. For example, gene expression changes alter inflammatory mediators, resulting in improved survival and growth of cancer cells and a more hospitable tissue environment. All of these events overlap at multiple points with events characteristic of "background" induction of breast carcinogenesis, including hormone-responsive proliferation, oxidative activity, and DNA damage. These overlaps make the breast particularly susceptible to ionizing radiation and reinforce that these biological activities are important characteristics of carcinogens. Agents that increase these biological processes should be considered potential breast carcinogens, and predictive methods are needed to identify chemicals that increase these processes. Techniques are available to measure RONS, DNA damage and mutation, cell proliferation, and some inflammatory proteins or processes. Improved assays are needed to measure GI and chronic inflammation, as well as the interaction with hormonally driven development and proliferation. Several methods measure diverse epigenetic changes, but it is not clear which changes are relevant to breast cancer. In addition, most toxicological assays are not conducted in mammary tissue, and so it is a priority to evaluate if results from other tissues are generalizable to breast, or to conduct assays in breast tissue. Developing and applying these assays to identify exposures of concern will facilitate efforts to reduce subsequent breast cancer risk.
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Affiliation(s)
- Jessica S Helm
- Silent Spring Institute, 320 Nevada Street, Suite 302, Newton, MA, 02460, USA
| | - Ruthann A Rudel
- Silent Spring Institute, 320 Nevada Street, Suite 302, Newton, MA, 02460, USA.
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10
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Helm JS, Rudel RA. Adverse outcome pathways for ionizing radiation and breast cancer involve direct and indirect DNA damage, oxidative stress, inflammation, genomic instability, and interaction with hormonal regulation of the breast. Arch Toxicol 2020; 94:1511-1549. [PMID: 32399610 PMCID: PMC7261741 DOI: 10.1007/s00204-020-02752-z] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Accepted: 04/16/2020] [Indexed: 12/15/2022]
Abstract
Knowledge about established breast carcinogens can support improved and modernized toxicological testing methods by identifying key mechanistic events. Ionizing radiation (IR) increases the risk of breast cancer, especially for women and for exposure at younger ages, and evidence overall supports a linear dose-response relationship. We used the Adverse Outcome Pathway (AOP) framework to outline and evaluate the evidence linking ionizing radiation with breast cancer from molecular initiating events to the adverse outcome through intermediate key events, creating a qualitative AOP. We identified key events based on review articles, searched PubMed for recent literature on key events and IR, and identified additional papers using references. We manually curated publications and evaluated data quality. Ionizing radiation directly and indirectly causes DNA damage and increases production of reactive oxygen and nitrogen species (RONS). RONS lead to DNA damage and epigenetic changes leading to mutations and genomic instability (GI). Proliferation amplifies the effects of DNA damage and mutations leading to the AO of breast cancer. Separately, RONS and DNA damage also increase inflammation. Inflammation contributes to direct and indirect effects (effects in cells not directly reached by IR) via positive feedback to RONS and DNA damage, and separately increases proliferation and breast cancer through pro-carcinogenic effects on cells and tissue. For example, gene expression changes alter inflammatory mediators, resulting in improved survival and growth of cancer cells and a more hospitable tissue environment. All of these events overlap at multiple points with events characteristic of "background" induction of breast carcinogenesis, including hormone-responsive proliferation, oxidative activity, and DNA damage. These overlaps make the breast particularly susceptible to ionizing radiation and reinforce that these biological activities are important characteristics of carcinogens. Agents that increase these biological processes should be considered potential breast carcinogens, and predictive methods are needed to identify chemicals that increase these processes. Techniques are available to measure RONS, DNA damage and mutation, cell proliferation, and some inflammatory proteins or processes. Improved assays are needed to measure GI and chronic inflammation, as well as the interaction with hormonally driven development and proliferation. Several methods measure diverse epigenetic changes, but it is not clear which changes are relevant to breast cancer. In addition, most toxicological assays are not conducted in mammary tissue, and so it is a priority to evaluate if results from other tissues are generalizable to breast, or to conduct assays in breast tissue. Developing and applying these assays to identify exposures of concern will facilitate efforts to reduce subsequent breast cancer risk.
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Affiliation(s)
- Jessica S Helm
- Silent Spring Institute, 320 Nevada Street, Suite 302, Newton, MA, 02460, USA
| | - Ruthann A Rudel
- Silent Spring Institute, 320 Nevada Street, Suite 302, Newton, MA, 02460, USA.
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11
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Hälg RA, Schneider U. Neutron dose and its measurement in proton therapy-current State of Knowledge. Br J Radiol 2020; 93:20190412. [PMID: 31868525 PMCID: PMC7066952 DOI: 10.1259/bjr.20190412] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Revised: 12/06/2019] [Accepted: 12/19/2019] [Indexed: 12/26/2022] Open
Abstract
Proton therapy has shown dosimetric advantages over conventional radiation therapy using photons. Although the integral dose for patients treated with proton therapy is low, concerns were raised about late effects like secondary cancer caused by dose depositions far away from the treated area. This is especially true for neutrons and therefore the stray dose contribution from neutrons in proton therapy is still being investigated. The higher biological effectiveness of neutrons compared to photons is the main cause of these concerns. The gold-standard in neutron dosimetry is measurements, but performing neutron measurements is challenging. Different approaches have been taken to overcome these difficulties, for instance with newly developed neutron detectors. Monte Carlo simulations is another common technique to assess the dose from secondary neutrons. Measurements and simulations are used to develop analytical models for fast neutron dose estimations. This article tries to summarize the developments in the different aspects of neutron dose in proton therapy since 2017. In general, low neutron doses have been reported, especially in active proton therapy. Although the published biological effectiveness of neutrons relative to photons regarding cancer induction is higher, it is unlikely that the neutron dose has a large impact on the second cancer risk of proton therapy patients.
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Determination of fast neutron RBE using a fully mechanistic computational model. Appl Radiat Isot 2020; 156:108952. [DOI: 10.1016/j.apradiso.2019.108952] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 10/11/2019] [Accepted: 10/21/2019] [Indexed: 11/19/2022]
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Zabihi A, Incerti S, Francis Z, Forozani G, Semsarha F, Moslehi A, Rezaeian P, Bernal MA. Computational approach to determine the relative biological effectiveness of fast neutrons using the Geant4-DNA toolkit and a DNA atomic model from the Protein Data Bank. Phys Rev E 2019; 99:052404. [PMID: 31212425 DOI: 10.1103/physreve.99.052404] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Indexed: 11/07/2022]
Abstract
This study proposes an innovative approach to estimate relative biological effectiveness (RBE) of fast neutrons using the Geant4 toolkit. The Geant4-DNA version cannot track heavy ions below 0.5 MeV/nucleon. In order to explore the impact of this issue, secondary particles are simulated instead of the primary low-energy neutrons. The Evaluated Nuclear Data File library is used to determine the cross sections for the elastic and inelastic interactions of neutrons with water and to find the contribution of each secondary particle spectrum. Two strategies are investigated in order to find the best possible approach and results. The first one takes into account only light particles, protons produced from elastic scattering, and α particles from inelastic scattering. Geantino particles are shot instead of heavy ions; hence all heavy ions are considered in the simulations, though their physical effects on DNA not. The second strategy takes into account all the heavy and light ions, although heavy ions cannot be tracked down to very low energies (E<0.5 MeV/nucleon). Our model is based on the combination of an atomic resolution DNA geometrical model and a Monte Carlo simulation toolkit for tracking particles. The atomic coordinates of the DNA double helix are extracted from the Protein Data Bank. Since secondary particle spectra are used instead of simulating the interaction of neutrons explicitly, this method reduces the computation times dramatically. Double-strand break induction is used as the end point for the estimation of the RBE of fast neutrons. ^{60}Co γ rays are used as the reference radiation quality. Both strategies succeed in reproducing the behavior of the RBE_{max} as a function of the incident neutron energy ranging from 0.1 to 14 MeV, including the position of its peak. A comparison of the behavior of the two strategies shows that for neutrons with energies less than 0.7 MeV, the effect of heavy ions would not be very significant, but above 0.7 MeV, heavy ions have an important role in neutron RBE.
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Affiliation(s)
- Azam Zabihi
- Department of Physics, Faculty of Science, Bu-Ali Sina University, Hamedan 651744161, Iran
| | - Sebastien Incerti
- University of Bordeaux, CENBG, UMR No. 5797, 33170 Gradignan, France CNRS, IN2P3, CENBG, UMR No. 5797, 33170 Gradignan, France
| | - Ziad Francis
- Department of Physics, Faculty of Sciences, Université Saint Joseph, 2020 1104 Beirut, Lebanon
| | - Ghasem Forozani
- Department of Physics, Payame Noor University, P.O. Box 19395-3697, Tehran, Iran
| | - Farid Semsarha
- Institute of Biochemistry and Biophysics, University of Tehran, P.O. Box 13145-1384, Tehran, Iran
| | - Amir Moslehi
- Radiation Applications Research School, Nuclear Science and Technology Research Institute, P.O. Box 11365-3486, Tehran, Iran
| | - Peiman Rezaeian
- Radiation Applications Research School, Nuclear Science and Technology Research Institute, P.O. Box 11365-3486, Tehran, Iran
| | - Mario A Bernal
- Instituto de Física Gleb Wataghin, Universidade Estadual de Campinas, Campinas, 13083-859 São Paulo, Brazil
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Imaoka T, Nishimura M, Daino K, Takabatake M, Moriyama H, Nishimura Y, Morioka T, Shimada Y, Kakinuma S. Risk of second cancer after ion beam radiotherapy: insights from animal carcinogenesis studies. Int J Radiat Biol 2019; 95:1431-1440. [PMID: 30495977 DOI: 10.1080/09553002.2018.1547848] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Purpose: To review recent studies to better understand the risk of second cancer after ion beam radiotherapy and to clarify the importance of animal radiobiology therein. Results: Risk of developing second cancer after radiotherapy is a concern, particularly for survivors of childhood tumors. Ion beam radiotherapy is expected to reduce the risk of second cancer by reducing exposure of normal tissues to radiation. Large uncertainty lies, however, in the choice of relative biological effectiveness (RBE) of high linear energy transfer (LET) radiation (e.g. carbon ions and neutrons) in cancer induction, especially for children. Studies have attempted to predict the risk of second cancer after ion beam radiotherapy based on an assessment of radiation dose, the risk of low LET radiation, and assumptions about RBE. Animal experiments have yielded RBE values for selected tissues, radiation types, and age at the time of irradiation; the results indicate potentially variable RBE which depends on tissues, ages, and dose levels. Animal studies have also attempted to identify genetic alterations in tumors induced by high LET radiation. Conclusions: Estimating the RBE value for cancer induction is important for understanding the risk of second cancer after ion beam radiotherapy. More comprehensive animal radiobiology studies are needed.
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Affiliation(s)
- Tatsuhiko Imaoka
- Department of Radiation Effects Research, National Institute of Radiological Sciences (NIRS), National Institutes for Quantum and Radiological Science and Technology (QST) , Chiba , Japan.,Tokyo Metropolitan University , Tokyo , Japan.,QST Advanced Study Laboratory, QST , Chiba , Japan
| | - Mayumi Nishimura
- Department of Radiation Effects Research, National Institute of Radiological Sciences (NIRS), National Institutes for Quantum and Radiological Science and Technology (QST) , Chiba , Japan
| | - Kazuhiro Daino
- Department of Radiation Effects Research, National Institute of Radiological Sciences (NIRS), National Institutes for Quantum and Radiological Science and Technology (QST) , Chiba , Japan
| | - Masaru Takabatake
- Department of Radiation Effects Research, National Institute of Radiological Sciences (NIRS), National Institutes for Quantum and Radiological Science and Technology (QST) , Chiba , Japan.,Tokyo Metropolitan University , Tokyo , Japan
| | - Hitomi Moriyama
- Department of Radiation Effects Research, National Institute of Radiological Sciences (NIRS), National Institutes for Quantum and Radiological Science and Technology (QST) , Chiba , Japan.,Tokyo Metropolitan University , Tokyo , Japan
| | - Yukiko Nishimura
- Department of Radiation Effects Research, National Institute of Radiological Sciences (NIRS), National Institutes for Quantum and Radiological Science and Technology (QST) , Chiba , Japan
| | - Takamitsu Morioka
- Department of Radiation Effects Research, National Institute of Radiological Sciences (NIRS), National Institutes for Quantum and Radiological Science and Technology (QST) , Chiba , Japan
| | | | - Shizuko Kakinuma
- Department of Radiation Effects Research, National Institute of Radiological Sciences (NIRS), National Institutes for Quantum and Radiological Science and Technology (QST) , Chiba , Japan
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Imaoka T, Nishimura M, Daino K, Hosoki A, Takabatake M, Nishimura Y, Kokubo T, Morioka T, Doi K, Shimada Y, Kakinuma S. Prominent Dose-Rate Effect and Its Age Dependence of Rat Mammary Carcinogenesis Induced by Continuous Gamma-Ray Exposure. Radiat Res 2018; 191:245-254. [PMID: 30543491 DOI: 10.1667/rr15094.1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Although the risk of breast cancer after high-dose-rate irradiation has been firmly established, however, the risk incurred for low-dose-rate irradiation is not well understood. Here we provide experimental evidence for dose rate and age dependencies induced by continuous γ-ray irradiation on mammary carcinogenesis. Female rats received continuous whole-body irradiation at one of the following time points: at 7 weeks of age (denoted adults) at a dose rate of 3-60 mGy/h (4 Gy total); or at either 3 weeks (denoted juveniles) or 7 weeks of age at a dose rate of 6 mGy/h (1-8 Gy total). Additional rats were acutely irradiated at 13 weeks of age at a dose rate of 30 Gy/h (0.5-4 Gy total). We observed the incidence of mammary tumors by weekly palpation until they were 90 weeks old and after pathological inspection upon autopsy. The tumor incidence rate for each group was characterized by Cox regression analysis. When adult rats were irradiated at 60 mGy/h for a total of 4 Gy, their hazard ratio for mammary carcinoma significantly increased relative to nonirradiated controls; however, for adult rats irradiated at 3-24 mGy/h, even though they also received a total of 4 Gy, their hazard ratio for carcinoma incidence did not significantly increase. A larger increase in the incidence rate of carcinoma per dose was found for the juveniles than for the adults irradiated at 6 mGy/h, whereas age did not influence the effect of acute irradiation at 30 Gy/h; a threshold-like dose response was observed for irradiation at 6 mGy/h (threshold, ∼2.5 and ∼4 Gy for juveniles and adults, respectively). Regarding benign tumors of the mammary gland, a significant increase in their incidence was observed for irradiation down to 6 mGy/h, but not at 3 mGy/h and there was no evidence of age-dependent induction. Thus, induction of female rat mammary carcinogenesis by continuous γ-ray exposure was age dependent and drastically increased for adult rats that received between 24 and 60 mGy/h irradiation.
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Affiliation(s)
- Tatsuhiko Imaoka
- a Department of Radiation Effects Research, National Institute of Radiological Sciences (NIRS), National Institutes for Quantum and Radiological Science and Technology (QST), Chiba, Japan.,d QST Advanced Study Laboratory, QST, Chiba, Japan.,e Tokyo Metropolitan University, Tokyo, Japan
| | - Mayumi Nishimura
- a Department of Radiation Effects Research, National Institute of Radiological Sciences (NIRS), National Institutes for Quantum and Radiological Science and Technology (QST), Chiba, Japan
| | - Kazuhiro Daino
- a Department of Radiation Effects Research, National Institute of Radiological Sciences (NIRS), National Institutes for Quantum and Radiological Science and Technology (QST), Chiba, Japan
| | - Ayaka Hosoki
- f Fukushima Project Headquarters, NIRS, Chiba, Japan
| | - Masaru Takabatake
- a Department of Radiation Effects Research, National Institute of Radiological Sciences (NIRS), National Institutes for Quantum and Radiological Science and Technology (QST), Chiba, Japan.,e Tokyo Metropolitan University, Tokyo, Japan
| | - Yukiko Nishimura
- a Department of Radiation Effects Research, National Institute of Radiological Sciences (NIRS), National Institutes for Quantum and Radiological Science and Technology (QST), Chiba, Japan
| | - Toshiaki Kokubo
- b Department of Engineering and Safety, National Institute of Radiological Sciences (NIRS), National Institutes for Quantum and Radiological Science and Technology (QST), Chiba, Japan
| | - Takamitsu Morioka
- a Department of Radiation Effects Research, National Institute of Radiological Sciences (NIRS), National Institutes for Quantum and Radiological Science and Technology (QST), Chiba, Japan
| | - Kazutaka Doi
- c Center for Radiation Protection Knowledge, National Institute of Radiological Sciences (NIRS), National Institutes for Quantum and Radiological Science and Technology (QST), Chiba, Japan
| | - Yoshiya Shimada
- e Tokyo Metropolitan University, Tokyo, Japan.,g Executive Director, QST, Chiba, Japan
| | - Shizuko Kakinuma
- a Department of Radiation Effects Research, National Institute of Radiological Sciences (NIRS), National Institutes for Quantum and Radiological Science and Technology (QST), Chiba, Japan
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Takabatake M, Daino K, Imaoka T, Blyth BJ, Kokubo T, Nishimura Y, Showler K, Hosoki A, Moriyama H, Nishimura M, Kakinuma S, Fukushi M, Shimada Y. Differential effect of parity on rat mammary carcinogenesis after pre- or post-pubertal exposure to radiation. Sci Rep 2018; 8:14325. [PMID: 30254198 PMCID: PMC6156598 DOI: 10.1038/s41598-018-32406-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Accepted: 09/03/2018] [Indexed: 01/28/2023] Open
Abstract
Radiation exposure during the peri-pubertal period is a proven risk factor for breast cancer, whereas parity is an established protective factor. The present study investigated whether parity imposes differential protective effects against radiation-induced rat mammary carcinoma depending on the age at exposure. Pre- and post-pubertal female rats, irradiated or left unirradiated, were mated and allowed to nurse until weaning or left unmated. Appearance of mammary tumors was monitored, and serum concentrations of estradiol and progesterone were measured following weaning. Carcinomas were evaluated by immunohistochemistry for estrogen receptor, progesterone receptor, and the cell proliferation marker Ki-67. Parity reduced the risk of carcinoma in unirradiated and pre-pubertally irradiated rats but not post-pubertally irradiated rats. Although radiation exposure increased serum progesterone level, parity after pre-pubertal exposure significantly decreased the elevated progesterone to a normal level, reflecting a protective effect. Moreover, parity significantly decreased the proportion of hormone receptor-positive carcinomas after pre-pubertal exposure. Parity was also related to the observed positive association between progesterone receptor and Ki-67 indices in cancer tissue, implying progesterone receptor-dependent cell proliferation. Thus, parity protects against radiation-induced rat mammary carcinogenesis depending on the age at exposure; the mechanisms may involve changes in hormone levels and cancer tissue.
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Affiliation(s)
- Masaru Takabatake
- Department of Radiation Effects Research, National Institute of Radiological Sciences (NIRS), National Institutes for Quantum and Radiological Science and Technology (QST), Chiba, 263-8555, Japan.
- Department of Radiological Sciences, Graduate School of Human Health Sciences, Tokyo Metropolitan University, Tokyo, 116-8551, Japan.
| | - Kazuhiro Daino
- Department of Radiation Effects Research, National Institute of Radiological Sciences (NIRS), National Institutes for Quantum and Radiological Science and Technology (QST), Chiba, 263-8555, Japan
| | - Tatsuhiko Imaoka
- Department of Radiation Effects Research, National Institute of Radiological Sciences (NIRS), National Institutes for Quantum and Radiological Science and Technology (QST), Chiba, 263-8555, Japan
- Department of Radiological Sciences, Graduate School of Human Health Sciences, Tokyo Metropolitan University, Tokyo, 116-8551, Japan
| | - Benjamin J Blyth
- Department of Radiation Effects Research, National Institute of Radiological Sciences (NIRS), National Institutes for Quantum and Radiological Science and Technology (QST), Chiba, 263-8555, Japan
- Division of Radiation Oncology and Cancer Imaging, Peter MacCallum Cancer Centre, Melbourne, Victoria, 3000, Australia
| | - Toshiaki Kokubo
- Department of Engineering and Safety, NIRS, QST, Chiba, 263-8555, Japan
| | - Yukiko Nishimura
- Department of Radiation Effects Research, National Institute of Radiological Sciences (NIRS), National Institutes for Quantum and Radiological Science and Technology (QST), Chiba, 263-8555, Japan
| | - Kaye Showler
- Department of Radiation Effects Research, National Institute of Radiological Sciences (NIRS), National Institutes for Quantum and Radiological Science and Technology (QST), Chiba, 263-8555, Japan
- Department of Radiological Sciences, Graduate School of Human Health Sciences, Tokyo Metropolitan University, Tokyo, 116-8551, Japan
- Department of Radiology, The Jikei University Hospital, Tokyo, 105-8471, Japan
| | - Ayaka Hosoki
- Department of Radiation Effects Research, National Institute of Radiological Sciences (NIRS), National Institutes for Quantum and Radiological Science and Technology (QST), Chiba, 263-8555, Japan
- Healios K.K. Kobe Research Institute, Kobe, 650-0047, Japan
| | - Hitomi Moriyama
- Department of Radiation Effects Research, National Institute of Radiological Sciences (NIRS), National Institutes for Quantum and Radiological Science and Technology (QST), Chiba, 263-8555, Japan
- Department of Radiological Sciences, Graduate School of Human Health Sciences, Tokyo Metropolitan University, Tokyo, 116-8551, Japan
| | - Mayumi Nishimura
- Department of Radiation Effects Research, National Institute of Radiological Sciences (NIRS), National Institutes for Quantum and Radiological Science and Technology (QST), Chiba, 263-8555, Japan
| | - Shizuko Kakinuma
- Department of Radiation Effects Research, National Institute of Radiological Sciences (NIRS), National Institutes for Quantum and Radiological Science and Technology (QST), Chiba, 263-8555, Japan
| | - Masahiro Fukushi
- Department of Radiological Sciences, Graduate School of Human Health Sciences, Tokyo Metropolitan University, Tokyo, 116-8551, Japan
| | - Yoshiya Shimada
- Department of Radiological Sciences, Graduate School of Human Health Sciences, Tokyo Metropolitan University, Tokyo, 116-8551, Japan.
- Executive Director, QST, Chiba, 263-8555, Japan.
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