| Project/Area Number |
16590738
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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 |
Respiratory organ internal medicine
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| Research Institution | Saitama Medical University (2006)
Tokyo Medical and Dental University (2004-2005) |
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Principal Investigator |
KOYAMA Nobuyuki (2005-2006) Saitama Medical University, Faculty of Medicine, Assistant Professor, 医学部, 講師 (30353460)
臼井 裕 (2004) 東京医科歯科大学, 医学部附属病院, 講師 (30292965)
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| Co-Investigator(Kenkyū-buntansha) |
小山 信之 東京医科歯科大学, 医学部附属病院, 助手 (30353460)
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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 |
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 2006: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 2005: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 2004: ¥1,900,000 (Direct Cost: ¥1,900,000)
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| Keywords | IGFBP-6 / SEMA3B / β-catenin / siRNA / flow cytometry / inhibition of cell proliferation / NCI-H1299 / microarray / Apoptosis / FACS Calibur / Colony formation assay / Cell growth assay / Microarray analysis / RASSF1A / RFMA3B / マイクロアレイ解析 / RNAi / 質量分析 |
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| Research Abstract |
Background : It is reported that semaphorin 3B (SEMA3B) binds neuropilin receptor (NRP) in competition with vascular endothelial growth factor receptor (VEGF), consequently inhibiting angiogenesis and cell proliferation through VEGF signaling pathway. On the other hand, it is possible that SEMA3B has an alternative mechanism for tumor suppression without mediating NRPs because the inhibitory effects on cell proliferation are different among another class 3 semaphorins such as SEMA3A, SEMA3C, and SEMA3F.
Method : Microarray analysis was used to examine the expression profile by exogenous SEMA3B expression in SEMA3B-null H1299 lung cancer cells, and attempted to identify the key molecule to exertion of SEMA3B function. Cell proliferation and soft agar colony formation assay by overexpression of an extracted candidate gene were performed, whereas tumor suppressive function of the target gene was investigated using siRNA treatment and flow cytometry. The regulatory correlation between SEMA3
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B and the target gene was also explored by immunohistochemistry. Furthermore, we analyzed transcriptional expression level of both the target gene and SEMA3B in 20 kinds of lung cancer and malignant mesothelioma cell lines to evaluate the effect of these genes on lung tumors.
Results : Microarray analysis revealed that SEMA3B significantly up-regulated insulin-like growth factor binding protein-6 (IGFBP-6), which was extracted as a candidate gene. Overexpression of IGFBP-6 elicited significant inhibition of cell proliferation in cell proliferation and soft agar colony formation assay. Flow cytometry showed that increased sub G0/G1 phase by exogenous SEMA3B in H1299 cells was restored by siRNA treatment for IGFBP-6. Immunohistochemistry revealed that exogenous SEMA3B resulted in intracellular delocalization of -catenin, which was known to down-regulate IGFBP-6. Both SEMA3B and IGFBP-6 were transcriptionally down-regulated in all of examined cell lines.
Discussion : SEMA3B elicits IGFBP-6-dependent inhibition of cell proliferation through intracellular delocalization of β-catenin. This novel mechanism might generally exert in lung tumors because transcriptional expressions of both SEMA3B and IGFBP-6 were decerased in all of 20 lung tumor cell line investigated, and offer clues to cancer therapy. Less
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