Elucidation of the mechanisms of proliferation/division, and metastasis of Sparganum proliferum and development of new treatment methods

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K07468
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 49040:Parasitology-related
• Research Institution: Jikei University School of Medicine
• Principal Investigator: Ishiwata Kenji 東京慈恵会医科大学, 医学部, 教授 (00241307)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: Sparganum proliferum / Biology / Therapeutics development

Outline of Final Research Achievements

Sparganum proliferum multiplies and disseminates in the human body without limitation, and is fatal if detected late. There is no effective treatment for this parasitic disease, and it is extremely rare worldwide, however, the number of cases in Japan is relatively large.
Parasites maintained in the mouse abdominal cavity were periodically collected, and image analysis of these worms confirmed that they grew at a nearly constant rate. In this evaluation system, high concentrations of praziquantel and albendazole had no effect. Respiratory chain enzymes of the worm were active both aerobically and anaerobically and were inhibited at very low concentrations by the complex I inhibitor. The drug efficacy was observed in a dye exclusion test after co-cultivation. Ultrastructurally, changes were observed in the mitochondria, perinuclear and external parts of the worm body at 1 day of incubation, and these series of drug effects were more potent under aerobic conditions.

Free Research Field

寄生虫学

Academic Significance and Societal Importance of the Research Achievements

芽殖孤虫症は極めて稀な寄生虫症であるが、無制限な増殖と播種(転移)に加えて、既存の治療薬が効かないということが致死率を上げている要因である。幼虫形が無制限に増殖し転移する条虫は、他にもエキノコックス症を引き起こす多包条虫および単包条虫があるが両種は胚芽細胞の増殖による。個体レベルで成長し、個体数を増やす様式の理解は、生物学的に大変興味深く、得られる知見は寄生虫学を超えて細胞学および発生生物学などの発展のみならず医療への応用が期待される。一方で、芽殖孤虫に有効な治療薬の開発は同時に、有効な治療薬のないエキノコックス症への応用が多いに期待される。