| Project/Area Number |
16390599
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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 |
Surgical dentistry
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| Research Institution | Kanagawa Dental College |
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Principal Investigator |
MATSUMOTO Goichi Kanagawa Dental College, Dentistry, Lecturer, 歯学部, 講師 (60199867)
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| Co-Investigator(Kenkyū-buntansha) |
LEE USSHAKU Kanagawa Dental College, Dentistry, Instructor, 歯学部, 助手 (90288085)
OMI Yasushi Kanagawa Dental College, Dentistry, Instructor, 歯学部, 助手 (10318892)
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| Project Period (FY) |
2004 – 2006
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| Project Status |
Completed (Fiscal Year 2006)
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| Budget Amount *help |
¥10,300,000 (Direct Cost: ¥10,300,000)
Fiscal Year 2006: ¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 2005: ¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 2004: ¥6,400,000 (Direct Cost: ¥6,400,000)
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| Keywords | siRNA / VEGF / SCC / Gene Therapy / angiogenesis / RNA干渉 / angiopoietin-1 / tumor angiogenesis / RNAi |
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| Research Abstract |
Double-stranded RNA (dsRNA) plays a major role in RNA interference (RNAi), a process in which segments of dsRNA are initially cleaved by the Dicer into shorter segments (21-23 nt) called small interfering RNA (siRNA). These siRNA then specifically target homologous mRNA molecules causing them to be degraded by cellular ribonucleases. RNAi down-regulates endogenous gene expression in mammalian cells. Vascular endothelial growth factor (VEGF) is a key molecule in vasculogenesis as well as in angiogenesis. Tumor growth is an angiogenesis-dependent process, and therapeutic strategies aimed at inhibiting angiogenesis are theoretically attractive.In order to investigate the feasibility of using the siRNA for VEGF in the specific knock-down of VEGF mRNA, thereby inhibiting angiogenesis, we have done experiments with a DNA vector based on a small interfering RNA system that targets VEGF (siVEGF). It almost completely inhibited the expression of three different isoforms (VEGF120, VEGF164 and VEGF188) of VEGF mRNA and the secretion of VEGF protein in mouse squamous cell carcinoma NRS-1 cells. The siVEGF released from cationized gelatin microspheres suppressed tumor growth in vivo. A marked reduction in vascularity accompanied the inhibition of a siVEGF-transfected tumor. Fluorescent microscopic study showed that the complex of siVEGF with cationized gelatin microspheres was still present around the tumor 10 days after injection, while free siVEGF had vanished by that time. Furthermore, siVEGF gene therapy increased the fraction of vessels covered by pericytes and induced expression of angiopoietin-1 by pericytes. These data suggest that cationized-gelatin microspheres containing siVEGF can be used to normalize tumor vasculature and inhibit tumor growth in an NRS-1 squamous cell carcinoma xenograft model.
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