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Fukunaga H, Yokoya A, Taki Y, Butterworth KT, Prise KM. Precision Radiotherapy and Radiation Risk Assessment: How Do We Overcome Radiogenomic Diversity? TOHOKU J EXP MED 2019; 247:223-235. [PMID: 30971620 DOI: 10.1620/tjem.247.223] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Precision medicine is a rapidly developing area that aims to deliver targeted therapies based on individual patient characteristics. However, current radiation treatment is not yet personalized; consequently, there is a critical need for specific patient characteristics of both tumor and normal tissues to be fully incorporated into dose prescription. Furthermore, current risk assessment following environmental, occupational, or accidental exposures to radiation is based on population effects, and does not account for individual diversity underpinning radiosensitivity. The lack of personalized approaches in both radiotherapy and radiation risk assessment resulted in the current situation where a population-based model, effective dose, is being used. In this review article, to stimulate scientific discussion for precision medicine in both radiotherapy and radiation risk assessment, we propose a novel radiological concept and metric - the personalized dose and the personalized risk index - that incorporate individual physiological, lifestyle-related and genomic variations and radiosensitivity, outlining the potential clinical application for precision medicine. We also review on recent progress in both genomics and biobanking research, which is promising for providing novel insights into individual radiosensitivity, and for creating a novel conceptual framework of precision radiotherapy and radiation risk assessment.
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Affiliation(s)
- Hisanori Fukunaga
- Centre for Cancer Research and Cell Biology, Queen's University Belfast
| | - Akinari Yokoya
- Tokai Quantum Beam Science Center, National Institutes for Quantum and Radiological Science and Technology
| | - Yasuyuki Taki
- Institute of Development, Aging and Cancer, Tohoku University
| | | | - Kevin M Prise
- Centre for Cancer Research and Cell Biology, Queen's University Belfast
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Affiliation(s)
- Andrzej Wojcik
- Centre for Radiation Protection Research, Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
- Department of Radiobiology and Immunology, Institute of Biology, Jan Kochanowski University, Kielce, Poland
| | - Mats Harms-Ringdahl
- Centre for Radiation Protection Research, Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
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Fukunaga H, Prise KM. Non-uniform radiation-induced biological responses at the tissue level involved in the health risk of environmental radiation: a radiobiological hypothesis. Environ Health 2018; 17:93. [PMID: 30630478 PMCID: PMC6329136 DOI: 10.1186/s12940-018-0444-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2018] [Accepted: 12/18/2018] [Indexed: 06/09/2023]
Abstract
BACKGROUND The conventional concept of radiation protection is based on epidemiological studies of radiation that support a positive correlation between dose and response. However, there is a remarkable difference in biological responses at the tissue level, depending on whether radiation is delivered as a uniform or non-uniform spatiotemporal distribution due to tissue sparing effects (TSE). From the point of view of radiation micro-dosimetry, environmental radiation is delivered as a non-uniform distribution, and radiation-induced biological responses at the tissue level, such as TSE, would be implicated in individual risk following exposure to environmental radiation. HYPOTHESIS We hypothesize that the health risks of non-uniform radiation exposure are lower than the same dose at a uniform exposure, due to TSE following irradiation. Testing the hypothesis requires both radiobiological studies using high-precision microbeams and the epidemiological data of environmental radiation-induced effects. The implications of the hypothesis will lead to more personalized approaches in the field of environmental radiation protection. CONCLUSION The detection of spatiotemporal dose distribution could be of scientific importance for more accurate individual risk assessment of exposure to environmental radiation. Further radiobiological studies on non-uniform radiation-induced biological responses at the tissue level are expected.
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Affiliation(s)
- Hisanori Fukunaga
- Centre for Cancer Research and Cell Biology, Queen’s University Belfast, 97 Lisburn Road, Belfast, BT9 7AE UK
| | - Kevin M. Prise
- Centre for Cancer Research and Cell Biology, Queen’s University Belfast, 97 Lisburn Road, Belfast, BT9 7AE UK
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Shimizu K, Yonekawa T, Yoshida M, Miyazato M, Miura A, Sakoda H, Yamaguchi H, Nakazato M. Conformational Change in the Ligand-Binding Pocket via a KISS1R Mutation (P147L) Leads to Isolated Gonadotropin-Releasing Hormone Deficiency. J Endocr Soc 2017; 1:1259-1271. [PMID: 29264451 PMCID: PMC5686787 DOI: 10.1210/js.2017-00277] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Accepted: 08/31/2017] [Indexed: 12/24/2022] Open
Abstract
Context: Kisspeptin receptor (KISS1R) is expressed in hypothalamic gonadotropin-releasing hormone neurons and responsible for pubertal onset and reproductive functions. KISS1R mutations remain a rare cause of congenital hypogonadotropic hypogonadism (CHH). Objective: The aim of this study was to identify the genetic cause of CHH in a patient and to functionally characterize a KISS1R mutation. Design: The patient was a 47-year-old Japanese man whose parents were first cousins. He lacked secondary sexual characteristics owing to normosmic CHH. Exon segments for the KISS1R gene in this patient were screened for mutations. Functional analyses were performed using HEK293 cells expressing KISS1R mutants. Molecular dynamics simulations were performed to compare the ligand-KISS1R mutant complex with those of wild-type KISS1R variants. Results: A homozygous mutation (c.440C>T, p.P147L) in KISS1R was identified. The P147L mutation did not affect either receptor expression level or subcellular localization in the recombinant expression system. Intracellular calcium measurements and cellular dielectric spectroscopy demonstrated that the P147L mutation impaired receptor function to an extent more severe than that of a previously reported L148S mutation. A receptor-ligand binding assay showed the P147L mutation causes a substantial loss of ligand-binding affinity. Molecular dynamics simulations revealed the P147L mutation decreases the contact surface area of the ligand-receptor complex in an expanded ligand-binding pocket. Conclusion: We identified a loss-of-function mutation in KISS1R associated with CHH. Our results demonstrated that the P147L mutation causes a severe phenotype and functional impairment resulting from the loss of ligand-binding affinity due to an expanded ligand-binding pocket.
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Affiliation(s)
- Koichiro Shimizu
- Division of Neurology, Respirology, Endocrinology, and Metabolism, Department of Internal Medicine, Faculty of Medicine, University of Miyazaki, 5200 Kihara, Kiyotake, Miyazaki City, Miyazaki 889-1602, Japan
| | - Tadato Yonekawa
- Division of Neurology, Respirology, Endocrinology, and Metabolism, Department of Internal Medicine, Faculty of Medicine, University of Miyazaki, 5200 Kihara, Kiyotake, Miyazaki City, Miyazaki 889-1602, Japan
| | - Morikatsu Yoshida
- Department of Biochemistry, National Cerebral and Cardiovascular Center Research Institute, 5-7-1 Fujishirodai, Suita, Osaka 565-8565, Japan
| | - Mikiya Miyazato
- Department of Biochemistry, National Cerebral and Cardiovascular Center Research Institute, 5-7-1 Fujishirodai, Suita, Osaka 565-8565, Japan
| | - Ayako Miura
- Division of Neurology, Respirology, Endocrinology, and Metabolism, Department of Internal Medicine, Faculty of Medicine, University of Miyazaki, 5200 Kihara, Kiyotake, Miyazaki City, Miyazaki 889-1602, Japan
| | - Hideyuki Sakoda
- Division of Neurology, Respirology, Endocrinology, and Metabolism, Department of Internal Medicine, Faculty of Medicine, University of Miyazaki, 5200 Kihara, Kiyotake, Miyazaki City, Miyazaki 889-1602, Japan
| | - Hideki Yamaguchi
- Division of Neurology, Respirology, Endocrinology, and Metabolism, Department of Internal Medicine, Faculty of Medicine, University of Miyazaki, 5200 Kihara, Kiyotake, Miyazaki City, Miyazaki 889-1602, Japan
| | - Masamitsu Nakazato
- Division of Neurology, Respirology, Endocrinology, and Metabolism, Department of Internal Medicine, Faculty of Medicine, University of Miyazaki, 5200 Kihara, Kiyotake, Miyazaki City, Miyazaki 889-1602, Japan
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