All Stories

  1. Nontoxic concentration of DNA ‐ PK inhibitor NU7441 radio‐sensitizes lung tumor cells with little effect on double strand break repair

    Article • Cancer Science, September 2016, Wiley

    Dr Ryuichi OKayasu

  2. Pre-Exposure to Ionizing Radiation Stimulates DNA Double Strand Break End Resection, Promoting the Use of Homologous Recombination Repair

    Article • PLoS ONE, March 2015, PLOS

    Dr Ryuichi OKayasu

  3. The combination of Hsp90 inhibitor 17 AAG and heavy‐ion irradiation provides effective tumor control in human lung cancer cells

    Article • Cancer Medicine, January 2015, Wiley

    Dr Ryuichi OKayasu

  4. Novel characteristics of CtIP at damage-induced foci following the initiation of DNA end resection

    Article • Mutation Research/Fundamental and Molecular Mechanisms of Mutagenesis, January 2015, Elsevier

    Dr Ryuichi OKayasu

  5. The complexity of DNA double strand break is a crucial factor for activating ATR signaling pathway for G2/M checkpoint regulation regardless of ATM function

    Article • DNA Repair, January 2015, Elsevier

    Dr Ryuichi OKayasu

  6. Heterochromatin Domain Number Correlates with X-Ray and Carbon-Ion Radiation Resistance in Cancer Cells

    Article • Radiation Research, October 2014, Radiation Research Society

    Dr Ryuichi OKayasu

  7. Carbon ion beam is more effective to induce cell death in sphere-type A172 human glioblastoma cells compared with X-rays

    Article • International Journal of Radiation Biology, August 2014, Taylor & Francis

    Dr Ryuichi OKayasu

  8. Dose-rate effect was observed in T98G glioma cells following BNCT

    Article • Applied Radiation and Isotopes, June 2014, Elsevier

    Dr Ryuichi OKayasu

  9. Introduction to NIRS International Open Laboratory (IOL)

    Article • Journal of Radiation Research, February 2014, Oxford University Press (OUP)

    Dr Ryuichi OKayasu

  10. The complexity of DNA double strand breaks is a critical factor enhancing end-resection

    Article • DNA Repair, November 2013, Elsevier

    Dr Ryuichi OKayasu

  11. OH Radicals from the Indirect Actions of X-Rays Induce Cell Lethality and Mediate the Majority of the Oxygen Enhancement Effect

    Article • Radiation Research, November 2013, Radiation Research Society

    Dr Ryuichi OKayasu

  12. Resistance of Bacillus subtilis Spore DNA to Lethal Ionizing Radiation Damage Relies Primarily on Spore Core Components and DNA Repair, with Minor Effects of Oxygen Radical Detoxification

    Article • Applied and Environmental Microbiology, October 2013, ASM Journals

    Dr Ryuichi OKayasu

  13. Visualisation of γH2AX Foci Caused by Heavy Ion Particle Traversal; Distinction between Core Track versus Non-Track Damage

    Article • PLoS ONE, August 2013, PLOS

    Dr Ryuichi OKayasu

  14. Chromosome aberrations in normal human fibroblasts analyzed in G0/G1 and G2/M phases after exposure in G0 to radiation with different linear energy transfer (LET)

    Article • Mutation Research/Genetic Toxicology and Environmental Mutagenesis, August 2013, Elsevier

    Dr Ryuichi OKayasu

  15. Evaluation of SCCVII tumor cell survival in clamped and non-clamped solid tumors exposed to carbon-ion beams in comparison to X-rays

    Article • Mutation Research/Genetic Toxicology and Environmental Mutagenesis, August 2013, Elsevier

    Dr Ryuichi OKayasu

  16. Selective Enhancing Effect of Early Mitotic Inhibitor 1 (Emi1) Depletion on the Sensitivity of Doxorubicin or X-ray Treatment in Human Cancer Cells

    Article • Journal of Biological Chemistry, May 2013, American Society for Biochemistry & Molecular Biology (ASBMB)

    Dr Ryuichi OKayasu, Dr Yasusei Kudo

  17. Parg deficiency confers radio-sensitization through enhanced cell death in mouse ES cells exposed to various forms of ionizing radiation

    Article • Biochemical and Biophysical Research Communications, May 2013, Elsevier

    Dr Ryuichi OKayasu

  18. Influence of track directions on the biological consequences in cells irradiated with high LET heavy ions

    Article • International Journal of Radiation Biology, February 2013, Taylor & Francis

    Dr Ryuichi OKayasu

  19. Radiation-Induced Delayed Genome Instability and Hypermutation in Mammalian Cells

    Article • January 2013, Springer Science + Business Media

    Dr Ryuichi OKayasu

  20. Relative biological effects of neutron mixed-beam irradiation for boron neutron capture therapy on cell survival and DNA double-strand breaks in cultured mammalian cells

    Article • Journal of Radiation Research, September 2012, Oxford University Press (OUP)

    Dr Ryuichi OKayasu

  21. Radiosensitization effect of poly(ADP-ribose) polymerase inhibition in cells exposed to low and high liner energy transfer radiation

    Article • Cancer Science, April 2012, Wiley

    Dr Ryuichi OKayasu

  22. ASPM influences DNA double-strand break repair and represents a potential target for radiotherapy

    Article • International Journal of Radiation Biology, November 2011, Taylor & Francis

    Dr Ryuichi OKayasu

  23. Repair of DNA damage induced by accelerated heavy ions-A mini review

    Article • International Journal of Cancer, October 2011, Wiley

    Dr Ryuichi OKayasu

  24. Radiosensitization Effect of PARP Inhibitor in Cells Exposed to Low and High LET Radiation

    Article • International Journal of Radiation Oncology*Biology*Physics, October 2011, Elsevier

    Dr Ryuichi OKayasu

  25. DNA double-strand break induction in Ku80-deficient CHO cells following Boron Neutron Capture Reaction

    Article • Radiation Oncology, September 2011, Springer Science + Business Media

    Dr Ryuichi OKayasu

  26. 1053 poster EFFECTS OF CARBON ION BEAM ON PUTATIVE COLON CANCER STEM CELLS AND ITS CORRELATION WITH RADIOCURABILITY

    Article • Radiotherapy and Oncology, May 2011, Elsevier

    Dr Ryuichi OKayasu

  27. Effectiveness of combined treatment using X-rays and a phosphoinositide 3-kinase inhibitor, ZSTK474, on proliferation of HeLa cells in vitro and in vivo

    Article • Cancer Science, April 2011, Wiley

    Dr Ryuichi OKayasu

  28. Effects of Carbon Ion Beam on Putative Colon Cancer Stem Cells and Its Comparison with X-rays

    Article • Cancer Research, March 2011, American Association for Cancer Research (AACR)

    Dr Ryuichi OKayasu

  29. Role of the Nfo and ExoA Apurinic/Apyrimidinic Endonucleases in Radiation Resistance and Radiation-Induced Mutagenesis of Bacillus subtilis Spores

    Article • Journal of Bacteriology, March 2011, ASM Journals

    Dr Ryuichi OKayasu

  30. In vitro characterization of cells derived from chordoma cell line U-CH1 following treatment with X-rays, heavy ions and chemotherapeutic drugs

    Article • Radiation Oncology, January 2011, Springer Science + Business Media

    Dr Ryuichi OKayasu

  31. Induction of DNA DSB and its rejoining in clamped and non-clamped tumours after exposure to carbon ion beams in comparison to X rays

    Article • Radiation Protection Dosimetry, December 2010, Oxford University Press (OUP)

    Dr Ryuichi OKayasu

  32. Rejoining kinetics of G1-PCC breaks induced by different heavy-ion beams with a similar LET value

    Article • Mutation Research/Genetic Toxicology and Environmental Mutagenesis, August 2010, Elsevier

    Dr Ryuichi OKayasu

  33. Astrobiological Aspects of the Mutagenesis of Cosmic Radiation on Bacterial Spores

    Article • Astrobiology, June 2010, Mary Ann Liebert Inc

    Dr Ryuichi OKayasu

  34. Ascorbic acid gives different protective effects in human cells exposed to X-rays and heavy ions

    Article • Mutation Research/Genetic Toxicology and Environmental Mutagenesis, June 2010, Elsevier

    Dr Ryuichi OKayasu

  35. Abstract 504: First in vitro radiobiological characterizations of cells from chordoma origin

    Article • Cancer Research, April 2010, American Association for Cancer Research (AACR)

    Dr Ryuichi OKayasu

  36. Recent Advances in the Biology of Heavy-Ion Cancer Therapy

    Article • Journal of Radiation Research, January 2010, Japan Radiation Research Society

    Dr Ryuichi OKayasu

  37. Enhanced radiation-induced cell killing by Herbimycin A pre-treatment

    Article • Radiation Physics and Chemistry, December 2009, Elsevier

    Dr Ryuichi OKayasu

  38. Radioprotection by DMSO in nitrogen-saturated mammalian cells exposed to helium ion beams

    Article • Radiation Physics and Chemistry, December 2009, Elsevier

    Dr Ryuichi OKayasu

  39. p53 independent radio-sensitization of human lymphoblastoid cell lines by Hsp90 inhibitor 17-allylamino-17-demethoxygeldanamycin

    Article • Oncology Reports, November 2009, Spandidos Publications

    Dr Ryuichi OKayasu

  40. Regulation of ATM in DNA double strand break repair accounts for the radiosensitivity in human cells exposed to high linear energy transfer ionizing radiation

    Article • Mutation Research/Fundamental and Molecular Mechanisms of Mutagenesis, November 2009, Elsevier

    Dr Ryuichi OKayasu

  41. ATM-Dependent Hyper-Radiosensitivity in Mammalian Cells Irradiated by Heavy Ions

    Article • International Journal of Radiation Oncology*Biology*Physics, September 2009, Elsevier

    Dr Ryuichi OKayasu

  42. Application of monochromatic keV X-ray source to X-ray drug delivery system

    Article • Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment, September 2009, Elsevier

    Dr Ryuichi OKayasu

  43. Signatures of DNA double strand breaks produced in irradiated G1 and G2 cells persist into mitosis

    Article • Journal of Cellular Physiology, June 2009, Wiley

    Dr Ryuichi OKayasu

  44. Chemopreventive agent sulforaphane enhances radiosensitivity in human tumor cells

    Article • International Journal of Cancer, April 2009, Wiley

    Dr Ryuichi OKayasu

  45. Contributions of Direct and Indirect Actions in Cell Killing by High-LET Radiations

    Article • Radiation Research, February 2009, Radiation Research Society

    Dr Ryuichi OKayasu

  46. The Influence of Mutation Induction in Normal Human Fibroblasts Irradiated with X Rays and Iron Ions

    Article • Biological Sciences in Space, January 2009, Japanese Society for Biological Sciences in Space

    Dr Ryuichi OKayasu

  47. Arsenic accumulation, elimination, and interaction with copper, zinc and manganese in liver and kidney of rats

    Article • Food and Chemical Toxicology, December 2008, Elsevier

    Dr Ryuichi OKayasu

  48. Sulforaphane induces DNA double strand breaks predominantly repaired by homologous recombination pathway in human cancer cells

    Article • Biochemical and Biophysical Research Communications, December 2008, Elsevier

    Dr Ryuichi OKayasu

  49. Metabolism and the Paradoxical Effects of Arsenic: Carcinogenesis and Anticancer

    Article • Current Medicinal Chemistry, September 2008, Bentham Science Publishers

    Dr Ryuichi OKayasu

  50. The Difference in LET and Ion Species Dependence for Induction of Initially Measured and Non-rejoined Chromatin Breaks in Normal Human Fibroblasts

    Article • Radiation Research, August 2008, Radiation Research Society

    Dr Ryuichi OKayasu

  51. Ionizing radiation downregulates ASPM, a gene responsible for microcephaly in humans

    Article • Biochemical and Biophysical Research Communications, May 2008, Elsevier

    Dr Ryuichi OKayasu

  52. Down regulation of BRCA2 causes radio-sensitization of human tumor cells in vitro and in vivo

    Article • Cancer Science, April 2008, Wiley

    Dr Ryuichi OKayasu

  53. Comparison of the induction and disappearance of DNA double strand breaks and γ-H2AX foci after irradiation of chromosomes in G1-phase or in condensed metaphase cells

    Article • Mutation Research/Fundamental and Molecular Mechanisms of Mutagenesis, March 2008, Elsevier

    Dr Ryuichi OKayasu

  54. High LET heavy ion radiation induces lower numbers of initial chromosome breaks with minimal repair than low LET radiation in normal human cells

    Article • Mutation Research/Genetic Toxicology and Environmental Mutagenesis, March 2008, Elsevier

    Dr Ryuichi OKayasu

  55. DNA topoisomerase inhibitor, etoposide, enhances GC-box-dependent promoter activity via Sp1 phosphorylation

    Article • Cancer Science, June 2007, Wiley

    Dr Ryuichi OKayasu

  56. Cellular signal transduction events as a function of linear energy transfer (LET)

    Article • Radiation Protection Dosimetry, May 2007, Oxford University Press (OUP)

    Dr Ryuichi OKayasu

  57. Enhancement of chromosomal aberrations in tumor cells with a non-labeled Cu-PTSM and irradiation with Cu K-shell monochromatic X rays

    Article • Radiation Protection Dosimetry, January 2007, Oxford University Press (OUP)

    Dr Ryuichi OKayasu

  58. Cytotoxicity of cigarette smoke condensate is not due to DNA double strand breaks: Comparative studies using radiosensitive mutant and wild-type CHO cells

    Article • International Journal of Radiation Biology, January 2007, Taylor & Francis

    Dr Ryuichi OKayasu

  59. The PCC assay can be used to predict radiosensitivity in biopsy cultures irradiated with different types of radiation

    Article • Oncology Reports, December 2006, Spandidos Publications

    Dr Ryuichi OKayasu

  60. Inhibition of homologous recombination repair in irradiated tumor cells pretreated with Hsp90 inhibitor 17-allylamino-17-demethoxygeldanamycin

    Article • Biochemical and Biophysical Research Communications, December 2006, Elsevier

    Dr Ryuichi OKayasu

  61. Repair of DNA Damage Induced by Accelerated Heavy Ions in Mammalian Cells Proficient and Deficient in the Non-homologous End-Joining Pathway

    Article • Radiation Research, January 2006, Radiation Research Society

    Dr Ryuichi OKayasu

  62. Caffeine Sensitizes Nondividing Human Fibroblasts to X Rays by Inducing a High Frequency of Misrepair

    Article • Radiation Research, October 2005, Radiation Research Society

    Dr Ryuichi OKayasu

  63. Radio-sensitivity of the Cells from Amyotrophic Lateral Sclerosis Model Mice Transfected with Human Mutant SOD1

    Article • Journal of Radiation Research, January 2005, Japan Radiation Research Society

    Dr Ryuichi OKayasu

  64. Facilitated detection of chromosome break and repair at low levels of ionizing radiation by addition of wortmannin to G1-type PCC fusion incubation

    Article • Mutation Research/Genetic Toxicology and Environmental Mutagenesis, August 2004, Elsevier

    Dr Ryuichi OKayasu

  65. Radiosensitization of Normal Human Cells by LY294002: Cell Killing and the Rejoining of DNA and Interphase Chromosome Breaks

    Article • Journal of Radiation Research, January 2003, Oxford University Press (OUP)

    Dr Ryuichi OKayasu

  66. Inhibition of DNA-double strand break repair by antimony compounds

    Article • Toxicology, December 2002, Elsevier

    Dr Ryuichi OKayasu

  67. Inhibition of radiation-induced DNA-double strand break repair by various metal/metalloid compounds

    Article • International Congress Series, July 2002, Elsevier

    Dr Ryuichi OKayasu

  68. Inhibition of Repair of Radiation-Induced DNA Double-Strand Breaks by Nickel and Arsenite

    Article • Radiation Research, December 2000, Radiation Research Society

    Dr Ryuichi OKayasu

  69. The phosphatidylinositol 3-kinase inhibitor wortmannin sensitizes quiescent but not proliferating MG-63 human osteosarcoma cells to radiation

    Article • Cancer Letters, November 1998, Elsevier

    Dr Ryuichi OKayasu

  70. Wortmannin Inhibits Repair of DNA Double-Strand Breaks in Irradiated Normal Human Cells

    Article • Radiation Research, May 1998, JSTOR

    Dr Ryuichi OKayasu

  71. Microsatellite instability in human mammary epithelial cells transformed by heavy ions

    Article • Advances in Space Research, January 1998, Elsevier

    Dr Ryuichi OKayasu

  72. Induction of DNA Double-Strand Breaks by Restriction Enzymes in X-Ray-Sensitive Mutant Chinese Hamster Ovary Cells Measured by Pulsed-Field Gel Electrophoresis

    Article • Radiation Research, February 1995, JSTOR

    Dr Ryuichi OKayasu

  73. Mitotic metaphase cells from different cell lines cause different levels of expression of the α-form of interphase chromosome breaks irradiated CHO cels

    Article • Mutation Research/Fundamental and Molecular Mechanisms of Mutagenesis, October 1994, Elsevier

    Dr Ryuichi OKayasu

  74. Evidence That the Product of the xrs Gene Is Predominantly Involved in the Repair of a Subset of Radiation-Induced Interphase Chromosome Breaks Rejoining with Fast Kinetics

    Article • Radiation Research, April 1994, JSTOR

    Dr Ryuichi OKayasu

  75. Ionizing Radiation Induces Two Forms of Interphase Chromosome Breaks in Chinese Hamster Ovary Cells That Rejoin with Different Kinetics and Show Different Sensitivity to Treatment in Hypertonic Medium or β-araA

    Article • Radiation Research, November 1993, JSTOR

    Dr Ryuichi OKayasu

  76. Increased frequency of formation of interphase ring-chromosomes in radiosensitive irs-1 cells exposed to X-rays

    Article • Mutation Research/DNA Repair, October 1993, Elsevier

    Dr Ryuichi OKayasu

  77. Hypertonic Treatment during Premature Chromosome Condensation Allows Visualization of Interphase Chromosome Breaks Repaired with Fast Kinetics in Irradiated CHO Cells

    Article • Radiation Research, August 1993, JSTOR

    Dr Ryuichi OKayasu

  78. Hypertonic Treatment Does Not Affect the Radiation Yield of Interphase Chromosome Breaks in DNA Double-Strand Break Repair-Deficient xrs-5 Cells

    Article • Radiation Research, August 1993, JSTOR

    Dr Ryuichi OKayasu

  79. Comparison of Yields and Repair Kinetics of Interphase Chromosome Breaks Visualized by Sendai-virus or PEG-mediated Cell Fusion in Irradiated CHO Cells

    Article • International Journal of Radiation Biology, January 1993, Taylor & Francis

    Dr Ryuichi OKayasu

  80. Induction by H 2 O 2 of DNA and Interphase Chromosome Damage in Plateau-Phase Chinese Hamster Ovary Cells

    Article • Radiation Research, August 1992, JSTOR

    Dr Ryuichi OKayasu

  81. The Shape of DNA Elution Dose-response Curves Under Non-denaturing Conditions: The Contribution of the Degree of Chromatin Condensation

    Article • International Journal of Radiation Biology, January 1992, Taylor & Francis

    Dr Ryuichi OKayasu

  82. Measurement of DNA Double Strand Breaks in Mammalian Cells: Comparison Between Pulsed Field Gel Electrophoresis and Non-Unwinding Filter Elution

    Article • January 1991, Springer Science + Business Media

    Dr Ryuichi OKayasu

  83. COMPARISON BETWEEN DNA DOUBLE STRAND BREAK REJOINING AND REJOINING OF CHROMATIN BREAKS IN IRRADIATED PLATEAU PHASE CHO CELLS

    Article • January 1991, Elsevier

    Dr Ryuichi OKayasu

  84. INDUCTION BY H2O2 OF DNA AND CHROMOSOME DAMAGE IN PLATEAU PHASE CHO CELLS

    Article • January 1991, Elsevier

    Dr Ryuichi OKayasu

  85. Radiosensitivity Throughout the Cell Cycle and Repair of Potentially Lethal Damage and DNA Double-strand Breaks in an X-ray-sensitive CHO Mutant

    Article • International Journal of Radiation Biology, January 1990, Taylor & Francis

    Dr Ryuichi OKayasu

  86. Effects of hyperthermia on the repair of radiation-induced DNA single-and double-strand breaks in DNA double-strand break repair-deficient and repair-proficient cell lines

    Article • International Journal of Hyperthermia, January 1990, Taylor & Francis

    Dr Ryuichi OKayasu

  87. Mechanism of Radiosensitization by Halogenated Pyrimidines: Effect of BrdU on Radiation Induction of DNA and Chromosome Damage and Its Correlation with Cell Killing

    Article • Radiation Research, August 1989, JSTOR

    Dr Ryuichi OKayasu

  88. Comparative studies on repair inhibition by AraA, AraC and aphidicolin of radiation induced dna and chromosome damage in rodent cells: Comparison with fixation of PLD

    Article • International Journal of Radiation Oncology*Biology*Physics, May 1989, Elsevier

    Dr Ryuichi OKayasu

  89. Linear DNA Elution Dose Response Curves Obtained in CHO Cells with Non-unwinding Filter Elution after Appropriate Selection of the Lysis Conditions

    Article • International Journal of Radiation Biology, January 1989, Taylor & Francis

    Dr Ryuichi OKayasu

  90. Variation through the Cell Cycle in the Dose-response of DNA Neutral Filter Elution in X-irradiated Synchronous CHO-cells

    Article • International Journal of Radiation Biology, January 1988, Taylor & Francis

    Dr Ryuichi OKayasu

  91. The Level of Induced DNA Double-strand Breaks Does Not Correlate with Cell Killing in X-irradiated Mitotic and G1-phase CHO Cells

    Article • International Journal of Radiation Biology, January 1988, Taylor & Francis

    Dr Ryuichi OKayasu

  92. Radiosensitive Xrs-5 and Parental CHO Cells Show Identical DNA Neutral Filter Elution Dose—response: Implications for a Relationship between Cell Radiosensitivity and Induction of DNA Double-strand Breaks

    Article • International Journal of Radiation Biology, January 1988, Taylor & Francis

    Dr Ryuichi OKayasu

  93. 125IdUrd-induced Chromosome Fragments, Assayed by Premature Chromosome Condensation, and DNA Double-strand Breaks Have Similar Repair Kinetics in G1-phase CHO-cells

    Article • International Journal of Radiation Biology and Related Studies in Physics Chemistry and Medicine, January 1987, Taylor & Francis

    Dr Ryuichi OKayasu