Innovative radio-theranostics by multi-step control system of tumor accumulation and background clearance

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K20122
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Research Field: Biomedical engineering and related fields
• Research Institution: The University of Tokyo (2019); National Cancer Center Japan (2017-2018)
• Principal Investigator: Umeda Izumi O. 東京大学, カブリ数物連携宇宙研究機構, 特任研究員 (40160791)
• Project Period (FY): 2017-06-30 – 2020-03-31
• Keywords: セラノスティックス / がん / 核医学治療 / 核医学画像診断 / クリアランス / 放射性核種

Outline of Final Research Achievements

The successful radio-theranostics requires to accumulate radionuclides (RI) in the target tissues with therapeutically enough amounts and to reduce normal tissue accumulation as much as possible, but it is hard to achieve both at the same time. In this study, we created RI-ligand complexes with rapid clearance ability, encapsulated them in liposomes with targeting property, and accumulated them as liposomes in the target tumors. On the other hand, we also succeeded to prompt the RI-ligand complexes clearance, by utilizing that liposomes were taken up and broken by the liver rapidly. RI-ligand complexes were released from liposomes and excreted to the urine. In this way, we constructed a multi-step control system of tumor accumulation and background clearance. Using Cu-64/67, which are used in radionuclide therapy, we were able to achieve both high accumulation in tumor and rapid clearance from normal tissues. The new radio-theranostics are promising.

Free Research Field

核医学

Academic Significance and Societal Importance of the Research Achievements

本研究の最終目的は浸潤や転移に至った進行がんをも治癒可能な革新的がん治療法の創出である。近年早期がんの治癒率は大きく向上したが、浸潤や転移を来した進行がんは未だ根治は難しい。放射性核種を含む化合物を患者に投与し、標的である腫瘍に集中して集積させ、放出放射線の強い殺細胞効果で直接癌細胞を死滅させる内用療法、さらに診断と治療を融合させた核医学セラノスティックスは次世代がん治療として期待されている。本研究の成果は核医学セラノスティックス実現を強力に推進するものであり、がん治療成績向上に大きく貢献しうる。