Use of radioactive copper (67Cu) makes effective and efficient cancer treatment possible

2023 Fiscal Year Final Research Report

• Project/Area Number: 20K08090
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 52040:Radiological sciences-related
• Research Institution: Suzuka University of Medical Science
• Principal Investigator: Iida Yasuhiko 鈴鹿医療科学大学, 薬学部, 教授 (60252425)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Keywords: 67Cu / 核医学治療 / がん / マウス / 神経内分泌腫瘍 / somatostatin / 放射性薬剤

Outline of Final Research Achievements

Copper-67 is an attractive radionuclide for nuclear medicine therapy, which has an emitted β-particle energy suitable for applying to small tumors (0.392 MeV) and a physical half-life of 61.8 hours long enough to damage them.
In this study, we prepared a novel somatostatin derivative, ToDBTTATE, labeled with 67Cu, and evaluated its potential for cancer therapy in mice bearing AR42J rat pancreatic tumor cells. 67Cu-ToDBTTATE showed high accumulation in the tumor and substantial tumor size reduction was observed in all mice treated with 67Cu-ToDBTTATE. Furthermore, mice with tumors of various sizes were prepared and the differences in the therapeutic effect of 67Cu-ToDBTTATE on the tumor size were examined to clarify the relationship between tumor size and the therapeutic effects of 67Cu-ToDBTTATE. As a result, a tumor growth constricting effect was observed in all mice compared with the control, but some tumor growth was observed in the group with a tumor size of more than 800 mm3.

Free Research Field

放射性薬品化学

Academic Significance and Societal Importance of the Research Achievements

国内で内用放射線療法に用いられている４核種以外にも治療での有効性が期待されるRIは多数存在する。この中で67Cuはβ－線のエネルギーが低く、十分な治療効果が得られるか不明である一方、大量投与が可能で、がん組織の状態によっては効果的・効率的な治療を実現することが期待できる。様々な腫瘍に対し67Cu標識薬剤の治療効果を検証することで低エネルギーβ－線の有効性が明らかになれば、様々なエネルギー、半減期を有する治療用RIの研究発展へとつながると考えられる。さらにこれらの成果は、患者の病態に合わせた効果的・効率的な治療、個別化医療に貢献することが期待される。