| Project/Area Number |
17500335
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Medical systems
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| Research Institution | Nara Medical University |
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Principal Investigator |
NAKAMURA Shinobu Nara Medical University, Faculty of Medicine, Professor, 医学部, 教授 (20019946)
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| Co-Investigator(Kenkyū-buntansha) |
FUJIMOTO Shin-ichi Nara Medical University, Faculty of Medicine, Associate professor, 医学部, 助教授 (70209097)
KANNO Masatoshi Nara Medical University, Faculty of Medicine, Lecturer, 医学部, 講師 (30195185)
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| Project Period (FY) |
2005 – 2006
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| Project Status |
Completed (Fiscal Year 2006)
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| Budget Amount *help |
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 2006: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 2005: ¥2,600,000 (Direct Cost: ¥2,600,000)
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| Keywords | Ultrasound / Molecular targeting agent / Anti-CD20 monoclonal antibody / Rituximab / Cell death / Apoptosis / Malignant tumor / 分子標的治療 |
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| Research Abstract |
1. Objective: To know whether ultrasound enhances the effect of molecular targeting therapy.
2. Methods:
(1) Cell line: SU-DHL-4 cells expressing CD20 antigen on the surface membrane were employed.
(2) Molecular targeting agent: Anti-CD20 monoclonal antibody, : rituximab, which has been introduced to treat for B-cell malignant lymphoma, was used.
(3) Induction of cell death by molecular targeting agent combined with ultrasound.
To determine the appropriate dose of rituximab, the cells were incubated in the concentration ranging from 10^<-1>μg/ml to 10^<-3>/μg/ml. It became clear that 10^<-2>μg/ml of rituximab is appropriate and minimal concentration for the induction of cell death on the cell line. From these results, 10^<-2>μg/ml of rituximab was used for the following study.
In order to know the effect of combination treatment of rituximab with ultrasound, sonication method was investigated. For excluding thermal effect and free radical production by ultrasound, the experiments were performed in lower than 40℃, 37℃ and in CO_2-saturated culture medium.
The cell death was observed using flow cytometer. Early apoptosis was determined by annexin V and secondary necrosis by propidium iodide.
3. Results and Comments
(1) Enhancement of effect of rituximab with ultrasound: Combination of the minimal effective concentration of rituximab: 10-2 μ g/ml, with sonication:2.5W/cm2 in 1MHz induced synergistic cell death of the cells.
(2) It seems that the cell death are induced through the mechanism of apoptosis, and then the cells become secondary necrosis.
From these results, it became clear that the effect of molecular targeting agents is enhanced by ultrasound. Further study is needed to introduce the ultrasound to treatment for malignant tumor.
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