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.
Quantifying initial cellular events of mouse radiation lymphomagenesis and its tumor prevention in vivo by positron emission tomography and magnetic resonance imaging.
利用統計を見る
Radiation-induced thymic lymphoma (RITL) in mice is induced by fractionated whole-body X-irradiation (FX) and has served as a useful model for studying radiation carcinogenesis. In this model, the initial postirradiation cellular events in the thymus and bone marrow (BM) are critically important for tumorigenesis, and BM transplantation (BMT) prevents RITL. However, direct assessment of these events is so far restricted by the lack of noninvasive monitoring techniques. Here, we have developed positron emission tomography (PET) and magnetic resonance imaging (MRI) methods to quantify the events critical for RITL development and the effects of BMT in living animals. Apparent diffusion coefficients (ADCs) were calculated from diffusion-weighted MRI to evaluate the changes in the BM of mice receiving FX. ADC values dramatically changed in the irradiated BM, corresponding to pathological findings of the irradiated BM, returning to normal levels following BMT sooner than with spontaneous recovery. PET with 4'-[methyl-(11)C]thiothymidine, a novel tracer for cell proliferation, revealed that the irradiated thymus showed significantly higher tracer uptake than the unirradiated thymus 1 week after FX. Interestingly, its increased uptake was completely abolished by BMT, even with very few donor-derived cells in the thymus. Thereafter, the thymus receiving BMT had significantly increased tracer uptake. These findings suggest that BMT first suppresses FX-induced aberrant thymocyte proliferation and then accelerates thymic regeneration. This study demonstrates the feasibility of using PET and MRI for noninvasive monitoring of tumorigenic cellular processes in an animal model of radiation-induced cancer.
Quantifying initial cellular events of mouse radiation lymphomagenesis and its tumor prevention in vivo by positron emission tomography and magnetic resonance imaging.
