| Project/Area Number |
17590803
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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 | KEIO UNIVERSITY |
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Principal Investigator |
SOEJIMA Kenzo Keio University, School of Medicine, Instructor, 医学部, 助手 (30236145)
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| Co-Investigator(Kenkyū-buntansha) |
NAOKI Katsuhiko Keio University, School of Medicine, Fellow, 医学部, 研究員 (40265806)
NAKACHI Ichiro Keio University, School of Medicine, Instructor, 医学部, 助手 (60348646)
KAWAMURA Masafumi Keio University, School of Medicine, Associate Professor, 医学部, 講師 (70169770)
川田 一郎 慶應義塾大学, 医学部, 研究員 (00327503)
江口 圭介 慶應義塾大学, 医学部, 助手 (90232941)
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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: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 2005: ¥2,800,000 (Direct Cost: ¥2,800,000)
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| Keywords | tumorigenesis / methylation / DNA methyltransferase / histone methyltransferase / microRNA / 肺癌 |
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| Research Abstract |
1.Epigenetic controls of gene expression by DNMTs and HMTs have been suggested to be important steps for tumor progression. We have established a transformed model of normal human bronchial epithelial (NHBE) cells by sequentially introducing hTERT, LT antigen and Ras into them. Introduction of hTERT and LT into NHBE cells immortalized and additional introduction of ras fully transformed them. We found those transformed cells had increased expression of the DNMT3b splice variant, DNMT3b3. Infection of these cells with adenoviruses encoding antisense DNMT3b abrogated their ability to grow in soft agar. Several tumor suppressor loci were hypermethylated and silenced. In some cases this could be reversed by antisense DNMT3b treatment. Thus DNMT3b may be one of the enzymes involved in de novo methylation of tumor suppressor loci. The HMT genes were also evaluated in our transformed model of NHBE cells. All of the HMTs except H3-K4 HMT, Set9 and Smyd3, increased after sequential introduction of LT and ras into NHBE cells. siRNA treatment for H3-K9 HMTs, Suv39h and G9a, significantly inhibited both their cell growth and tumorigenesis, while siRNA treatment for H3-K27 HMT, Ezh2 only affected tumorigenesis in transformed NHBE cells. These data suggested dysregulated. H3-K9 and K27 HMTs contributed for immortalization and oncogenic transformation.
2.To investigate the roles of microRNAs on DNA methylation, we first screened aberrantly expressed microRNAs in the transformed NHBE cells using miRNA microarray. Next, we are searching for common sequence motifs of methylation in the transformed cells using bioinformatics (DRIM algorithm) in list of ranked sequences obtained by methyl-DNA immunoprecipitation and promoter array. In case we can find out the same or identical sequences between the screened microRNAs and the common sequence motifs, we are planning to transport the microRNAs into non-tranformed NHBE cells to see changes in DNA methylation in the future.
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