量研学術機関リポジトリ「QST-Repository」は、国立研究開発法人 量子科学技術研究開発機構に所属する職員等が生み出した学術成果（学会誌発表論文、学会発表、研究開発報告書、特許等）を集積しインターネット上で広く公開するサービスです。 Welcome to QST-Repository where we accumulates and discloses the academic research results(Journal Publications, Conference presentation, Research and Development Report, Patent, etc.) of the members of National Institutes for Quantum Science and Technology.
Thank you very much for using our website. On the 11th of March 2019, this site was moved from our own network server to the JAIRO Cloud network server. If you previously bookmarked this site, that bookmark will no longer work. We would be grateful if you could bookmark the website again. Thank you very much for your understanding and cooperation.
Radiation therapy(RT) using high-energy radiation such as X-ray and charged particles, is one of the common treatments for cancer. During the past few decades, RT has been evolved in response to a change in technologies. However it still has the potential to improve clinical outcomes, including the patient quality of life after RT, by using biological and chemical approaches.
We have been interested in combination drugs for RT, especially radioprotectors (RPs) and radiosensitizers (RSs). A RP is defined to protect normal tissues around the treated tumor from irradiation to prevent adverse reactions, such as second primary cancer. However, only Amifostine has been approved by the FDA to protect normal tissues from radiation during RT. RSs are applied to make cancer cells more sensitive to RT. A large number of chemical compounds, which show radioprotective/sensitize effects by chemical analysis, is known, but only a part of them were assessed for their effects on cell lines or animal models. A reason for this gap is that conventional methods have some bottlenecks to achieve high-throughput screening, due to requirement of relatively large amount of compounds, higher cost and complexity of the methods. To accelerate drug development for RPs and RSs, we invented a novel high-throughput method for screening lots of candidates. This method utilizes the radiation-induced shrinkage of thymocytes (TCs), which is well known as a major morphological change connected with apoptosis, to evaluate protective- or sensitize-effect of tested chemicals against radiation. The TCs were pretreated with candidates followed by 2 Gy X-irradiation. After irradiation, these cells were incubated for 4 h and then the cell size of TCs were immediately measured on a flow cytometer. The protective effect of some natural antioxidants against radiation-induced apoptosis in the rat TCs, as well as their toxicities without X-irradiation, was successfully evaluated using this method. In addition, to reduce assay volume and to adjust high-contents analysis, we further developed the method by using fluorescence dyes with the imaging cytometer. This method is able to lower the assay volume and assay time to be less than 1/5 compared with the previous method.
Here, I will present our recent results to evaluate candidate compounds by using the two methods.
会議概要（会議名, 開催地, 会期, 主催者等）
15th International Congress of Radiation Research (ICRR 2015)
High-throughput Screening of Radioprotectors/sensitizers Using Thymocytes
