Ryo Kunimoto

Kyoto University, Kioto, Kyōto, Japan

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Publications (7)31.52 Total impact

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    ABSTRACT: We synthesized a series of N(1)-substituted norcymserine derivatives 7a-p and evaluated their anti-cholinesterase activities. In vitro evaluation showed that the pyridinylethyl derivatives 7m-o and the piperidinylethyl derivative 7p improved the anti-butyrylcholinesterase activity by approximately threefold compared to N(1)-phenethylnorcymserine (PEC, 2). A quantitative structure-activity relationship (QSAR) study indicated that logS might be a key feature of the improved compounds.
    Bioorganic & medicinal chemistry letters 03/2010; 20(5):1718-20. DOI:10.1016/j.bmcl.2010.01.057 · 2.33 Impact Factor
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    ABSTRACT: DNA microarray technology provides us with a first step toward the goal of uncovering gene functions on a genomic scale. In recent years, vast amounts of gene expression data have been collected, much of which are available in public databases, such as the Gene Expression Omnibus (GEO). To date, most researchers have been manually retrieving data from databases through web browsers using accession numbers (IDs) or keywords, but gene-expression patterns are not considered when retrieving such data. The Connectivity Map was recently introduced to compare gene expression data by introducing gene-expression signatures (represented by a set of genes with up- or down-regulated labels according to their biological states) and is available as a web tool for detecting similar gene-expression signatures from a limited data set (approximately 7,000 expression profiles representing 1,309 compounds). In order to support researchers to utilize the public gene expression data more effectively, we developed a web tool for finding similar gene expression data and generating its co-expression networks from a publicly available database. GEM-TREND, a web tool for searching gene expression data, allows users to search data from GEO using gene-expression signatures or gene expression ratio data as a query and retrieve gene expression data by comparing gene-expression pattern between the query and GEO gene expression data. The comparison methods are based on the nonparametric, rank-based pattern matching approach of Lamb et al. (Science 2006) with the additional calculation of statistical significance. The web tool was tested using gene expression ratio data randomly extracted from the GEO and with in-house microarray data, respectively. The results validated the ability of GEM-TREND to retrieve gene expression entries biologically related to a query from GEO. For further analysis, a network visualization interface is also provided, whereby genes and gene annotations are dynamically linked to external data repositories. GEM-TREND was developed to retrieve gene expression data by comparing query gene-expression pattern with those of GEO gene expression data. It could be a very useful resource for finding similar gene expression profiles and constructing its gene co-expression networks from a publicly available database. GEM-TREND was designed to be user-friendly and is expected to support knowledge discovery. GEM-TREND is freely available at http://cgs.pharm.kyoto-u.ac.jp/services/network.
    BMC Genomics 10/2009; 10:411. DOI:10.1186/1471-2164-10-411 · 4.04 Impact Factor
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    ABSTRACT: MicroRNAs (miRNAs) are small noncoding RNAs that negatively regulate protein-coding genes. To identify miRNAs that have a tumor suppressive function in bladder cancer (BC), 156 miRNAs were screened in 14 BCs, 5 normal bladder epithelium (NBE) samples and 3 BC cell lines. We identified a subset of 7 miRNAs (miR-145, miR-30a-3p, miR-133a, miR-133b, miR-195, miR-125b and miR-199a*) that were significantly downregulated in BCs. To confirm these results, 104 BCs and 31 NBEs were subjected to real-time RT-PCR-based experiments, and the expression levels of each miRNA were significantly downregulated in BCs (p < 0.0001 in all). Receiver-operating characteristic curve analysis revealed that the expression levels of these miRNAs had good sensitivity (>70%) and specificity (>75%) to distinguish BC from NBE. Our target search algorithm and gene-expression profiling in BCs (Kawakami et al., Oncol Rep 2006;16:521-31) revealed that Keratin7 (KRT7) mRNA was a common target of the downregulated miRNAs, and the mRNA expression levels of KRT7 were significantly higher in BCs than in NBEs (p = 0.0004). Spearman rank correlation analysis revealed significant inverse correlations between KRT7 mRNA expression and each downregulated miRNA (p < 0.0001 in all). Gain-of-function analysis revealed that KRT7 mRNA was significantly reduced by transfection of 3 miRNAs (miR-30-3p, miR-133a and miR-199a*) in the BC cell line (KK47). In addition, significant decreases in cell growth were observed after transfection of 3 miRNAs and si-KRT7 in KK47, suggesting that miR-30-3p, miR-133a and miR-199a* may have a tumor suppressive function through the mechanism underlying transcriptional repression of KRT7.
    International Journal of Cancer 07/2009; 125(2):345-52. DOI:10.1002/ijc.24390 · 5.01 Impact Factor
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    ABSTRACT: MicroRNAs are small noncoding RNA species, some of which are playing important roles in cell differentiation. However, the level of participations of microRNAs in epithelial cell differentiation is largely unknown. Here, utilizing an epithelial differentiation model with T84 cells, we demonstrate that miR-338-3p and miR-451 contribute to the formation of epithelial basolateral polarity by facilitating translocalization of beta1 integrin to the basolateral membrane. Among 250 microRNAs screened in this study, the expression levels of four microRNAs (miR-33a, 210, 338-3p and 451) were significantly elevated in the differentiated stage of T84 cells, when epithelial cell polarity was established. To investigate the involvement of these microRNAs in terms of epithelial cell polarity, we executed loss-of- and gain-of-function analyses of these microRNAs. The blockade of endogenous miR-338-3p or miR-451 via each microRNA-specific antisense oligonucleotides inhibited the translocalization of beta1 integrin to the basolateral membrane, whereas inhibition of miR-210 or miR-33a had no effect on it. On the other hand, simultaneous transfection of synthetic miR-338-3p and miR-451 accelerated the translocalization of beta1 integrin to the basolateral membrane, although the introduction of individual synthetic microRNAs exhibited no effect. Therefore, we concluded that both miR-338-3p and miR-451 are necessary for the development of epithelial cell polarity.
    Nucleic Acids Research 05/2009; 37(11):3821-7. DOI:10.1093/nar/gkp255 · 8.81 Impact Factor
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    ABSTRACT: Micro-RNAs (miRNAs) are evolutionarily conserved small noncoding RNAs (20– 23 nucleotides). MiRNAs regulate various physiological pathways such as differentiation, proliferation, and apoptosis by negative regulation of the gene expressions at the posttranscriptional level [1–3]. Currently, more than 800 human miRNAs have been identified and registered in the miRNA database miRBase [4]. Strikingly, 30% of protein-coding transcripts in humans is predicted to be regulated by miR-NAs [5,6]. Recently, miRNAs have been reported to work as oncogenes or tumor suppressor genes and be directly involved in the initiation, progression, and metastasis of various cancers [7–9]. Therefore, we focus on the role that miRNAs play in cancer and the use of miRNAs in drug discovery. Collection of evidence suggests that miRNAs can be potentially useful for understanding tumorigenesis and finding novel strategies for cancer diagnosis and therapy.
    12/2008: pages 183-189;
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    ABSTRACT: G-protein coupled receptors (GPCRs) represent one of the most important families of drug targets in pharmaceutical development. GLIDA is a public GPCR-related Chemical Genomics database that is primarily focused on the integration of information between GPCRs and their ligands. It provides interaction data between GPCRs and their ligands, along with chemical information on the ligands, as well as biological information regarding GPCRs. These data are connected with each other in a relational database, allowing users in the field of Chemical Genomics research to easily retrieve such information from either biological or chemical starting points. GLIDA includes a variety of similarity search functions for the GPCRs and for their ligands. Thus, GLIDA can provide correlation maps linking the searched homologous GPCRs (or ligands) with their ligands (or GPCRs). By analyzing the correlation patterns between GPCRs and ligands, we can gain more detailed knowledge about their conserved molecular recognition patterns and improve drug design efforts by focusing on inferred candidates for GPCR-specific drugs. This article provides a summary of the GLIDA database and user facilities, and describes recent improvements to database design, data contents, ligand classification programs, similarity search options and graphical interfaces. GLIDA is publicly available at http://pharminfo.pharm.kyoto-u.ac.jp/services/glida/. We hope that it will prove very useful for Chemical Genomics research and GPCR-related drug discovery.
    Nucleic Acids Research 02/2008; 36(Database issue):D907-12. DOI:10.1093/nar/gkm948 · 8.81 Impact Factor
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    ABSTRACT: Microribonucleic acids (miRNAs) are small noncoding RNAs that negatively regulate gene expression at the posttranscriptional level. Although considerable progress has been made in studying the function of miRNAs, they still remain largely unclear, mainly because of the difficulty in identifying target genes for miRNA. We performed a global analysis of both miRNAs and mRNAs expression across 16 human cell lines and extracted negatively correlated pairs of miRNA and mRNA which indicate miRNA-target relationship. The many of known-target of miR-124a showed negative correlation, suggesting our analysis were valid. We further extracted physically relevant miRNA-target gene pairs, applying computational target prediction algorithm with inverse correlations of miRNA and messenger RNA (mRNA) expression. Furthermore, gene-ontology-based annotation and functional enrichment analysis of the extracted miRNA-target gene pairs made it possible to indicate putative functions of miRNAs. The data collected here will be of value for further studies into the function of miRNA.
    Journal of Human Genetics 02/2008; 53(6):515-23. DOI:10.1007/s10038-008-0279-x · 2.53 Impact Factor