Dept. of Basic Medical Sciences for Radiation Damages

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 In order to achieve effective decorporation after nuclear accident and subsequent radiation injury treatment, our department has been focusing on basic medical studies for understanding the molecular basis of the effects and injuries caused by radiations including heavy particle ions. On the current 7-Year Plan, we are especially attempting to introduce regenerative medicine into the field of radiation injury treatment; approaches employing regenerative medicine must shed light not only on radiation injury treatment, but also on the treatments after radiation therapies including heavy particle beam therapy. Further, we are also conducting experimental studies for radionuclide therapy, which would be a main target of future clinical applications of radiation. For achieving these objectives we have six research teams: ‘Internal Decorporation Research’, ‘Molecular and Cellular Radiation Biology’, ‘Quantitative RedOx Sensing’, ‘Radiation and Cancer Biology’, ‘Regenerative Therapy Research’ and ‘Stem Cell Biology’ teams.

Research Theme

Studies on internal contamination and decomtamination of actinides and radionuclides.

We have been conducting a basic research for applying regenerative medicine to therapy of radiation injuries. We focus on the pluripotent stem cells, especially on their genome, because a huge amount of knowledge of DNA repair mechanisms, genomes integrity, has been accumulated to date. iPS cells, which were discovered by Dr. Yamanaka and his colleagues in 2006, hold a great promise for regenerative medicine, since these stem cells can be established from each patient, resulting in basically no immunogenicity.
However, on the other hand, a substantial number of point mutations have been unexpectedly identified in their genomes, and the findings raised a considerable concern over the clinical use of iPS cells, since it could affect crucial issues, immunogenicity and tumorigenicity. Current our aim is to understand the mechanisms underlying the mutations, and subsequently to reduce the mutation frequency for preparing a high quality stem cells.

Study on the genome stability of stem cells

We have been conducting a basic research for applying regenerative medicine to therapy of radiation injuries. We focus on the pluripotent stem cells, especially on their genome, because a huge amount of knowledge of DNA repair mechanisms, genomes integrity, has been accumulated to date. iPS cells, which were discovered by Dr. Yamanaka and his colleagues in 2006, hold a great promise for regenerative medicine, since these stem cells can be established from each patient, resulting in basically no immunogenicity. However, on the other hand, a substantial number of point mutations have been unexpectedly identified in their genomes, and the findings raised a considerable concern over the clinical use of iPS cells, since it could affect crucial issues, immunogenicity and tumorigenicity. Current our aim is to understand the mechanisms underlying the mutations, and subsequently to reduce the mutation frequency for preparing a high quality stem cells.

 

Research for the treatment of radiation injuries with growth factors

This research project aims at developing the treatments and preventions for radiation injuries following accidental exposure to a high dose of radiation, or adverse reactions such as radiation alopecia and gastrointestinal symptoms after radiation therapies. This project also focuses on elucidating radiation-induced DNA damage repair mechanisms and control of cell survival/death decision, thereby clarifying their roles in radiation injuries. In addition, the functions of growth factors (FGFs) and extracellular matrices (carbohydrates) in the niches of tissue stem cells during tissue regeneration after radiation exposure are studied in order to create the novel bioactive molecules for radioprotections and medications.

 

Radiation & cancer biology for next generation radiation therapy and medicine

This research focus is radiation and cancer biology for next generation radiation therapy and medicine. We are studying targeted radionuclide therapy with high LET particle radiation such as alpha-particles and Auger electrons that is highly cytotoxic against cancer cells, and radiation injuries including radiation-induced cancers. We are also studying the biological basis to accelerate heavy-ion radiation therapy.

Biomedical research for the application to human health of novel types of artificial and environmental radiations

Radiation effect on human being is variable depending on the dose, dose rate and the source of radiaions(photon, accelerated particles, nuclear elements). We have been studying genomic signatures (i.e. biomolecules, chromosomal activities) responding to IR, some of which were obtained under such restricted conditions as at extremely low dose or at higher LET particle radiations. We noted that modifiction of these novel signatures can affect the cellular radiosensitivity, also depending on the states of the exposed cells in the tissue organization and the development periods. Aim of our research is to understand pathological bases under the radioresistance of cancer stemness and IR-induced tumorigenesis. We will employ the most updated animal models in the comparison study of the cells/tissues between normal and susceptible individuals (ATM, scid, BRCA, etc.).

 

Researching molecular mechanisms of primary radiation damages through Quantitative Redox Sensing

The challenges of Quantitative Redox Sensing Team are 1) identification and quantification of radiation-induced reactive species, i.e. free radicals and/or reactive oxygen species, caused in aqueous or lipidic environments, 2) evaluation of the primary density of those reactive species, 3) prediction of sequential redox chain-reactions, 4) seeking ways of chemical reactions to trigger biological responses and 5) elucidation of impact of LET on radiation induced biological responses. Goals of our research are to figure out chemical mechanisms of bio-molecular damages by ionizing radiations, and to chemically regulate radio-biological responses.

 

Research Team

  • Internal Decorporation Research Team
  • Radiation and Cancer Biology Team
  • Stem Cell Biology Team
  • Regenerative Therapy Research Team
  • Molecular and Cellular Radiation Biology Team
  • Quantitative RedOx Sensing Team

Links

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4-9-1 Anagawa, Inage-ku, Chiba-shi, Chiba 263-8555, Japan Tel: +81-43-206-3025 (outside of Japan), or 043-206-3025 (in Japan)