| Project/Area Number |
15300163
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Biomedical engineering/Biological material science
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| Research Institution | Osaka University |
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Principal Investigator |
KANEDA Yasufumi Osaka University, Graduate School of Medicine, Professor, 医学系研究科, 教授 (10177537)
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| Project Period (FY) |
2003 – 2004
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| Project Status |
Completed (Fiscal Year 2004)
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| Budget Amount *help |
¥13,300,000 (Direct Cost: ¥13,300,000)
Fiscal Year 2004: ¥6,400,000 (Direct Cost: ¥6,400,000)
Fiscal Year 2003: ¥6,900,000 (Direct Cost: ¥6,900,000)
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| Keywords | HVJ envelope vector / siRNA / cisplatin / Rad51 / cancer therapy / HVJ-E / ブレオマイシン / ドラッグデリバリーシステム / 癌 |
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| Research Abstract |
Every cancer therapy appears to be transiently effective for cancer regression, but cancers gradually transform to be resistant to the therapy. Cancers also develop machineries to resist chemotherapy. Short interfering RNA (siRNA) has been evaluated as an attractive and effective tool for suppressing target protein by specifically digesting its mRNA. Suppression of the machineries using siRNA may enhance the sensitivity to chemotherapy in cancers when combined with effective delivery system. To enhance the anti-cancer effect of chemotherapy, we tested the ability of short interfering RNA(siRNA) to inhibit chemotherapy-resistant gene expression. We found that Rad51 was enhanced with cis-diamminedichloroplatinum (II) (CDDP ; cisplatin) in cancer cells. Overexpression of Rad51 caused cancer cells to become resistant to CDDP. When synthetic Rad 51 siRNA was delivered to HeLa cells using HVJ (hemagglutinating virus of Japan, Sendai virus) envelope vector, the delivery efficiency of siRNA was approximately 100%. No Rad51 transcripts were detected on day 2, and Rad51 protein completely disappeared for 4 days after siRNA transfer. The combination of Rad51 siRNA and CDDP caused increased DNA damage, which was detected by pulsed-field gel electrophoresis. When HeLa cells were incubated with 0.02 μg/ml CDDP for 3 hours after siRNA transfer, the number of colonies decreased to approximately 10% of that with scrambled siRNA. When Rad51 siRNA was delivered into tumors using HVJ envelope vector, the delivery efficiency was approximately 50%, and the Rad51 transcript level was reduced by approximately 60%. Rad51 siRNA combined with CDDP significantly inhibited the tumor growth when compared to siRNA or CDDP alone.
Our results suggest that the combination of CDDP and Rad51 siRNA will be an effective anti-cancer protocol.
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