Research Topics
Species | Ryuichi OkayasuSummaryAffiliation: National Institute of Radiological Sciences Country: Japan Publications
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Detail Information
Publications
DNA double-strand break induction in Ku80-deficient CHO cells following boron neutron capture reactionYuko Kinashi
Research Reactor Institute, Kyoto University, Sennan gun, Osaka, Japan
Radiat Oncol 6:106. 2011..The purpose of this study is to verify that BNCR will increase cell killing and slow disappearance of repair protein-related foci to a greater extent in DNA repair-deficient cells than in wild-type cells...
Repair of DNA damage induced by accelerated heavy ions--a mini reviewRyuichi Okayasu
International Open Laboratory and Heavy ion Radiobiology Research Group, Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, Inage Ku, Chiba, Japan
Int J Cancer 130:991-1000. 2012..Accelerated heavy ions have become valuable tools to investigate the molecular mechanisms underlying repair of DNA DSBs, the most crucial form of DNA damage induced by radiation and various chemotherapeutic agents...
Induction of DNA double strand breaks by arsenite: comparative studies with DNA breaks induced by X-raysRyuichi Okayasu
International Space Radiation Laboratory and Environmental Toxicological Research Group, National Institute of Radiological Sciences, 4 9 1 Anagawa, Inage Ku, Chiba 263 8555, Japan
DNA Repair (Amst) 2:309-14. 2003..Based on these data, further mechanistic investigations including the involvement of DNA-DSB repair proteins are warranted in the recovery process from arsenic (As) exposure...- Radiosensitization of normal human cells by LY294002: cell killing and the rejoining of DNA and interphase chromosome breaksRyuichi Okayasu
International Space Radiation Laboratory, National Institute of Radiological Sciences, Inage Ku, Chiba, Japan
J Radiat Res 44:329-33. 2003..These results suggest that the inhibition of DSB repair mediated the radiosensitizing effect of LY294002 at the dose level that we used... - Repair of DNA damage induced by accelerated heavy ions in mammalian cells proficient and deficient in the non-homologous end-joining pathwayRyuichi Okayasu
International Space Radiation Laboratory, National Institute of Radiological Sciences, Inage Ku, Chiba shi 263 8555, Japan
Radiat Res 165:59-67. 2006..This delay was further emphasized in NHEJ-defective 180BR cells. Our results indicate that high-LET radiation induces complex DNA damage that is not easily repaired or is not repaired by NHEJ even at low radiation doses such as 2 Gy... - Rejoining kinetics of G1-PCC breaks induced by different heavy-ion beams with a similar LET valueChizuru Tsuruoka
Heavy Ion Radiobiology Research Group, National Institute of Radiological Sciences, 4 9 1 Anagawa, Chiba 263 8555, Japan
Mutat Res 701:47-51. 2010.... - Sulforaphane induces DNA double strand breaks predominantly repaired by homologous recombination pathway in human cancer cellsEmiko Sekine-Suzuki
Heavy Ion Radiobiology Research Group, Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, 4 9 1 Anagawa, Inage Ku, Chiba 263 8555, Japan
Biochem Biophys Res Commun 377:341-5. 2008..G2/M arrest by SFN, a typical response for cells exposed to ionizing radiation was also observed. Our new data indicate the clear induction of DSBs by SFN and a useful anti-tumor aspect of SFN through the induction of DNA DSBs... - The difference in LET and ion species dependence for induction of initially measured and non-rejoined chromatin breaks in normal human fibroblastsChizuru Tsuruoka
Heavy Ion Radiobiology Research Group, National Institute of Radiological Sciences, 4 9 1 Anagawa, Chiba, Japan
Radiat Res 170:163-71. 2008..This suggests that the LET-dependent structure in the biological effects is reflected in biological consequences of repair processes... - High LET heavy ion radiation induces lower numbers of initial chromosome breaks with minimal repair than low LET radiation in normal human cellsEmiko Sekine
Heavy Ion Radiobiology Research Group, National Institute of Radiological Sciences, 4 9 1 Anagawa, Inage Ku, Chiba shi 263 8555, Japan
Mutat Res 652:95-101. 2008..These results at the chromosome level substantiate and extend the notion that high LET radiation produces complex-type DNA double strand breaks (DSBs)... - Down regulation of BRCA2 causes radio-sensitization of human tumor cells in vitro and in vivoDong Yu
Heavy Ion Radiobiology Research Group, Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, 4 9 1 Anagawa, Inage Ku, Chiba shi, 263 8555, Japan
Cancer Sci 99:810-5. 2008.... - Chemopreventive agent sulforaphane enhances radiosensitivity in human tumor cellsDong Yu
Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, Inage Ku, Chiba shi, Japan
Int J Cancer 125:1205-11. 2009..To the best of our knowledge, our study is the first report showing SFN-enhanced radiosensitivity of tumor cells in vitro and in vivo, which opens the door for a multitude of clinical applications for chemoradiotherapy using SFN... - Inhibition of DNA-double strand break repair by antimony compoundsSentaro Takahashi
Environmental and Toxicological Research Group, National Institute of Radiological Sciences, 4 9 1 Anagawa, Inage Ku, 263 8555, Chiba, Japan
Toxicology 180:249-56. 2002..This is the first report to indicate that antimony compounds may inhibit the repair of radiation-induced DNA DSB... - ASPM influences DNA double-strand break repair and represents a potential target for radiotherapyTakamitsu A Kato
Heavy Ion Radiobiology Research Group, Center for Charged Particle Therapy, National Institute of Radiological Sciences, 4 9 1 Anagawa, Inage Ku, Chiba shi, Chiba, Japan
Int J Radiat Biol 87:1189-95. 2011..The roles of ASPM on radiosensitivity, however, have never been studied... - In vitro characterization of cells derived from chordoma cell line U-CH1 following treatment with X-rays, heavy ions and chemotherapeutic drugsTakamitsu A Kato
Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, 4 9 1 Anagawa, Inage Ku, Chiba shi, 263 8555 Japan
Radiat Oncol 6:116. 2011..In order to overcome this situation, we successfully derived a cell line with a shorter doubling time from the first validated chordoma line U-CH1 and obtained invaluable cell biological data... - Effectiveness of combined treatment using X-rays and a phosphoinositide 3-kinase inhibitor, ZSTK474, on proliferation of HeLa cells in vitro and in vivoKazunori Anzai
Heavy Ion Radiobiology Research Group, National Institute of Radiological Sciences, Chiba, Japan
Cancer Sci 102:1176-80. 2011..Combined treatment with X-rays and ZSTK474 has greater therapeutic potential than radiation or drug therapy alone, both in vitro and in vivo... - The PCC assay can be used to predict radiosensitivity in biopsy cultures irradiated with different types of radiationMasao Suzuki
Heavy Ion Radiobiology Research Group, National Institute of Radiological Sciences, Chiba 263, Japan
Oncol Rep 16:1293-9. 2006.... - Ascorbic acid gives different protective effects in human cells exposed to X-rays and heavy ionsYoshihiro Fujii
Research Center for Charged Particle Therapy, Heavy Ion Radiobiology Research Group, National Institute of Radiological Sciences, Inage Ku, Chiba shi, Japan
Mutat Res 699:58-61. 2010..These findings provide new insight into the mechanism of DNA damage and repair produced by heavy ion irradiation... - Contributions of direct and indirect actions in cell killing by high-LET radiationsRyoichi Hirayama
Heavy Ion Radiobiology Research Group, Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, 4 9 1 Anagawa, Inage Ku, Chiba 263 8555, Japan
Radiat Res 171:212-8. 2009..However, the peak value was much higher for RBE(D) (5.99) than RBE(I) (1.89). Thus direct action contributes more to the high RBE of high-LET radiations than indirect action does... - Inhibition of homologous recombination repair in irradiated tumor cells pretreated with Hsp90 inhibitor 17-allylamino-17-demethoxygeldanamycinMiho Noguchi
Graduate School of Science and Technology, Chiba University, Inage Ku, Chiba 263 8522, Japan
Biochem Biophys Res Commun 351:658-63. 2006..Our data demonstrate for the first time that 17-AAG inhibits the HR repair process and could provide a new therapeutic strategy to selectively result in higher tumor cell killing... - Caffeine sensitizes nondividing human fibroblasts to x rays by inducing a high frequency of misrepairTetsuya Kawata
Department of Radiology, Graduate School of Medicine, Chiba, Japan
Radiat Res 164:509-13. 2005..Since most DNA repair in nongrowing G0 cells is believed to result from nonhomologous end joining (NHEJ), caffeine may influence the fidelity of the NHEJ pathway in irradiated G0 cells... - Effects of carbon ion beam on putative colon cancer stem cells and its comparison with X-raysXing Cui
Heavy Ion Radiobiology Research Group, Research Center for Radiation Emergency Medicine, National Institute of Radiological Sciences NIRS, Chiba, Japan
Cancer Res 71:3676-87. 2011..Taken together, carbon ion beam therapy may have an advantage over photon beam therapy by improved targeting of putative colon cancer stem-like cells... - Ionizing radiation downregulates ASPM, a gene responsible for microcephaly in humansAkira Fujimori
Cellular and Molecular Biology Team, National Institute of Radiological Sciences, Heavy Ion Radiobiology Research Group, Research Center for Charged Particle Therapy, 4 9 1 Anagawa, Inage, Chiba 263 8555, Japan
Biochem Biophys Res Commun 369:953-7. 2008..A similar suppression was observed in the irradiated neurosphere cultures. This is the first report suggesting that the suppression of Aspm by IR could be the initial molecular target leading to the future microcephaly formation... - Arsenic accumulation, elimination, and interaction with copper, zinc and manganese in liver and kidney of ratsXing Cui
Environmental Health Sciences Division, National Institute for Environmental Studies, Ibaraki 305 8506, Japan
Food Chem Toxicol 46:3646-50. 2008..These data indicate that arsenic is widely distributed and significantly accumulated in various organs and influences on other trace elements, and also modulates MT-1 expression in the liver and kidney... - Metabolism and the paradoxical effects of arsenic: carcinogenesis and anticancerXing Cui
Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, Chiba, Chiba 263 8555, Japan
Curr Med Chem 15:2293-304. 2008..We also summarize the clinical use of arsenic trioxide (As2O3) to date and discuss new therapeutic strategies such as concurrent arsenic-radiation therapy to achieve local tumor control and enhance the radiosensitivity of solid tumors... - Extremely low dose ionizing radiation up-regulates CXC chemokines in normal human fibroblastsAkira Fujimori
Environmental and Toxicological Sciences Research Group, Research Center for Radiation Safety, National Institute of Radiological Sciences, 4 9 1 Anagawa, Inage, Chiba, Japan
Cancer Res 65:10159-63. 2005..In addition, our comprehensive approach using a novel expression profiling method is a powerful strategy to explore biological functions associated with very low levels of toxic agents... - Facilitated detection of chromosome break and repair at low levels of ionizing radiation by addition of wortmannin to G1-type PCC fusion incubationMaki Okada
International Space Radiation Laboratory, Research Center for Radiation Safety, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan
Mutat Res 562:11-7. 2004..Our chromosome repair assay is useful for evaluating the accuracy of other assays measuring DNA DSB repair at doses equal or less than 0.5 Gy of ionizing radiation... - Roles of the major, small, acid-soluble spore proteins and spore-specific and universal DNA repair mechanisms in resistance of Bacillus subtilis spores to ionizing radiation from X rays and high-energy charged-particle bombardmentRalf Moeller
German Aerospace Center, Institute of Aerospace Medicine, Radiation Biology Division, Department of Photo and Exobiology, Cologne, Germany
J Bacteriol 190:1134-40. 2008.... - Radio-sensitivity of the cells from amyotrophic lateral sclerosis model mice transfected with human mutant SOD1Reika Wate
Department of Neurology, Kansai Medical University, Moriguchi, Japan
J Radiat Res (Tokyo) 46:67-73. 2005.... - Cytotoxicity of cigarette smoke condensate is not due to DNA double strand breaks: Comparative studies using radiosensitive mutant and wild-type CHO cellsTakamitsu Kato
Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, USA
Int J Radiat Biol 83:583-91. 2007.... - Comparison of the induction and disappearance of DNA double strand breaks and gamma-H2AX foci after irradiation of chromosomes in G1-phase or in condensed metaphase cellsTakamitsu A Kato
Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, CO 80523, United States
Mutat Res 639:108-12. 2008..On the other hand, no difference was seen for the gel electrophoresis assay. Our data may suggest the limited accessibility of dephosphorylation enzyme in irradiated metaphase cells or trapped gamma-H2AX in condensed chromatin... - Enhancement of chromosomal aberrations in tumor cells with a non-labeled Cu-PTSM and irradiation with Cu K-shell monochromatic X raysKaoru Takakura
Physics Department, Division of Natural Sciences, International Christian University, Mitaka shi, Tokyo 181 8585, Japan
Radiat Prot Dosimetry 122:188-94. 2006..In this study, uniqueness in physical property such as Cu atom K-shell ionisation was applied for the enhancement of biological effects in cancer cells... - Silencing expression of the catalytic subunit of DNA-dependent protein kinase by small interfering RNA sensitizes human cells for radiation-induced chromosome damage, cell killing, and mutationYuanlin Peng
CO St U, Ft. Collins
Cancer Res 62:6400-4. 2002.... - DNA topoisomerase inhibitor, etoposide, enhances GC-box-dependent promoter activity via Sp1 phosphorylationIchiro Niina
Department of Molecular Biology, School of Medicine, University of Occupational and Environmental Health, Iseigaoka, Fukuoka, Japan
Cancer Sci 98:858-63. 2007..Taken together, these findings demonstrate a novel genomic response to anticancer agents that induce Sp1 phosphorylation, and might contribute to tumor progression and drug resistance...