Biomedical subjects

Yusuke Nakamura

Publications and source records attributed to Yusuke Nakamura.

At least 217 records · Page 12Linked to original sources

PubMed2002

Catalog of 77 single-nucleotide polymorphisms (SNPs) in the carbohydrate sulfotransferase 1 (CHST1) and carbohydrate sulfotransferase 3 (CHST3) genes.

Individual phenotypes with respect to drug response or toxicity often result from genetic variations that alter drug metabolism. We have been focusing on genomic loci that encode various enzymes and transporters involved in the metabolism of drugs, and have described more than 1200 single-nucleotide polymorphisms (SNPs) and other variations. Regarding the carbohydrate sulfotransferase (CHST) gene family, we have already constructed high-density SNP maps of three genomic segments that included CHST2, CHST4, and CHST5, providing a total of 28 SNPs for those loci. In the present study, we screened DNA from 48 healthy Japanese volunteers for SNPs at the CHST1 and CHST3 gene loci, by means of direct sequencing combined with a polymerase chain reaction method for amplifying genomic DNA, and characterized 77 SNPs and four insertion-deletion polymorphisms. The collection of human variations presented here adds to the archive of tools now available for investigating complex genetic diseases, population migration patterns, and a variety of pharmacogenetic possibilities.

DNA↗

PubMed2002

Three hundred twenty-six genetic variations in genes encoding nine members of ATP-binding cassette, subfamily B (ABCB/MDR/TAP), in the Japanese population.

We screened DNAs from 48 Japanese individuals for single-nucleotide polymorphisms (SNPs) in nine genes encoding components of ATP-binding cassette subfamily B (ABCB/MDR/TAP) by directly sequencing the entire applicable genomic regions except for repetitive elements. This approach identified 297 SNPs and 29 insertion/deletion polymorphisms among the nine genes. Of the 297 SNPs, 50 were identified in the ABCB1 gene, 14 in TAP], 35 in TAP2, 48 in ABCB4, 13 in ABCB7, 21 in ABCB8, 21 in ABCB9, 13 in ABCB10, and 82 in ABCB11. Thirteen were located in 5' flanking regions, 237 in introns, 37 in exons, and 10 in 3' flanking regions. These variants may contribute to investigations of possible correlations between genotypes and disease-susceptibility phenotypes or responsiveness to drug therapy.

ATP Binding Cassette Transporter, Subfamily B↗

PubMed2002

Thirteen single-nucleotide polymorphisms (SNPs) in the alcohol dehydrogenase 4 (ADH4) gene locus.

The human alcohol dehydrogenase 4 (ADH4) gene encodes the class II ADH4 pi subunit, which contributes to the metabolization of a wide variety of substrates, including ethanol, retinol, other aliphatic alcohols, hydroxysteroids, and lipid peroxidation products. Here we report the results of systematic screening for single-nucleotide polymorphisms (SNPs) in the ADH4 gene by means of direct sequencing combined with a polymerase chain reaction method. A total of 16 genetic variations including 13 SNPs were found; 4 in the 5' flanking region, 4 in the 5' untranslated region, and 8 within introns. No variation was found in coding, 3' untranslated, or 3' flanking regions. Eight of the 13 SNPs were not reported in the NCBI dbSNP database or any previous publications. Our SNP map presented here should provide tools to evaluate the role of ADH4 in complex genetic diseases and a variety of pharmacogenetic effects.

Alcohol Dehydrogenase↗

PubMed2002

Identification of 779 genetic variations in eight genes encoding members of the ATP-binding cassette, subfamily C (ABCC/MRP/CFTR.

We screened DNAs from 48 Japanese individuals for single-nucleotide polymorphisms (SNPs) in eight genes encoding the ATP-binding cassette, subfamily C (ABCC/ MRP/CFTR), by direct sequencing of their entire genomic regions, except repetitive sequence elements. This approach identified 688 SNPs and 91 insertion/deletion polymorphisms among the eight genes. Of the 688 SNPs, 81 were identified in the ABCC1 gene, 41 in ABCC2, 30 in ABCC3, 230 in ABCC4, 76 in ABCC5, 58 in CFTR, 102 in ABCC8. and 70 in ABCC9. Six SNPs were located in the 5' flanking regions, 617 in introns, 46 in exons, and 19 in the 3' flanking regions. These variants should contribute to studies that investigate possible correlations of genotypes with disease-susceptibility phenotypes and responsiveness or adverse effects to drugs.

ATP-Binding Cassette Transporters↗

PubMed2002

Twenty single-nucleotide polymorphisms in four genes encoding cardiac ion channels.

We here report 20 novel single-nucleotide polymorphisms in four genes that are potentially involved in the excitement of cardiomyocytes: 1 in KCNA5 (encoding Kv1.5), 5 in KCNAB1 (encoding Kvbeta1.3), 5 in KCNIP2 (encoding KChIP2), and 9 in CACNA1C (encoding a cardiac L-type voltage-dependent calcium ion channel, dihydropyridine receptor). We also examined their allelic frequencies in Japanese individuals. These data will be useful for genetic association studies designed to investigate secondary long QT syndrome or other circulatory disorders.

Gene Frequency↗

PubMed2002

Characterization of a VNTR polymorphism in the coding region of the CEL gene.

Human carboxyl ester lipase (CEL) secreted by the pancreas into the duodenum is a glycoprotein playing an essential role in the intestinal processing of cholesterol and lipid-soluble vitamins. The gene encoding CEL was known to contain a tandemly repeated sequence of the 11-amino-acid motif in the C-terminal region. We characterized its polymorphic features and found that there are five different alleles in Japanese populations and six in Caucasians. The allele containing 16 repeats is the most common in both populations. Although the distribution of the alleles seemed to be different in the two populations, the difference was not statistically significant. This polymorphism may influence the function of this enzyme and be a useful genetic marker to study diseases associated with cholesterol absorption.

Asian People↗

PubMed2002

Identification of CAG repeat-containing genes expressed in human brain as candidate genes for autosomal dominant spinocerebellar ataxias and other neurodegenerative diseases.

To obtain novel candidate genes for autosomal dominant spinocerebellar ataxia and other neurodegenerative disorders in which gene mutations remain unidentified, we screened a human fetal brain cDNA library using (CAG)(10) repeat probes. Sixteen cDNAs were isolated and mapped to chromosomes 1, 2, 3, 6, 9, 13, 15, 16, 22, and X. Although we failed to detect abnormal CAG repeat expansion within these genes in Japanese patients with inherited neurodegenerative diseases, these genes remain potential candidate genes for neurodegenerative diseases that feature anticipation.

Brain↗

PubMed2002

Catalog of 605 single-nucleotide polymorphisms (SNPs) among 13 genes encoding human ATP-binding cassette transporters: ABCA4, ABCA7, ABCA8, ABCD1, ABCD3, ABCD4, ABCE1, ABCF1, ABCG1, ABCG2, ABCG4, ABCG5, and ABCG8.

Single-nucleotide polymorphisms (SNPs) at some gene loci are useful as markers of individual risk for adverse drug reactions or susceptibility to complex diseases. We have been focusing on identifying SNPs in and around genes encoding drug-metabolizing enzymes and transporters, and have constructed several high-density SNP maps of such regions. Here we report SNPs at additional loci, specifically 13 genes belonging to the superfamily of ATP-binding cassette transporters ( ABCA4, ABCA7, ABCA8, ABCD1, ABCD3, ABCD4, ABCE1, ABCF1, ABCG1, ABCG2, ABCG4, ABCG5, and ABCG8). Sequencing a total of 416 kb of genomic DNA from 48 Japanese volunteers identified 605 SNPs among these 13 loci: 14 in 5' flanking regions, 5 in 5' untranslated regions, 37 within coding elements, 529 in introns, 8 in 3' untranslated regions, and 12 in 3' flanking regions. By comparing our data with SNPs deposited in the dbSNP database of the National Center for Biotechnology Information (US) and with published reports, we determined that 491 (81%) of the SNPs reported here were novel. We also detected 107 genetic variations of other types among the loci examined (insertion-deletions or mono- di-, or trinucleotide polymorphisms). The high-density SNP maps we constructed on the basis of these data should provide useful information for investigating associations between genetic variations and common diseases or responsiveness to drug therapy.

ATP-Binding Cassette Transporters↗

PubMed2002

906 variations among 27 genes encoding cytochrome P450 (CYP) enzymes and aldehyde dehydrogenases (ALDHs) in the Japanese population.

We screened DNAs from 48 Japanese individuals for single-nucleotide polymorphisms (SNPs) in genes encoding 13 cytochrome P450 (CYP) enzymes and 14 aldehyde dehydrogenases (ALDHs) by directly sequencing their entire genomic regions except for repetitive elements. This approach identified 810 SNPs and 96 insertion/deletion polymorphisms among the 27 genes. Of the 810 SNPs, 229 were identified among the CYP genes and 581 in the ALDH genes; of the total, 48 SNPs were located in 5' flanking regions, 619 in introns, 91 in exons, and 52 in 3' flanking regions. These variants should contribute to studies designed to investigate possible correlations between genotypes and phenotypes of disease susceptibility or responsiveness to drug therapy.

Aldehyde Dehydrogenase↗

PubMed2002

Absence of mutation in the NOD2/CARD15 gene among 483 Japanese patients with Crohn's disease.

Chronic inflammatory bowel diseases (IBDs), specifically Crohn's disease (CD) and ulcerative colitis (UC), have increased significantly in western countries and Japan over the last decade, but very little is known about their pathogenesis. A candidate-gene approach recently identified NOD2/CARD15 as one susceptibility gene from the IBD1 locus on chromosome 16. Alterations in this gene were found in many Caucasian patients with CD; in particular, two nonsynonymous substitutions (R702W and G908R) and a frameshift mutation (1007fs) were shown to be independent risk factors for CD. We investigated DNA from 483 Japanese CD patients to detect those three mutations in NOD2/CARD15 by appropriate genotyping techniques, but found only an R702Q substitution in a single patient. Direct sequencing of DNA from 96 of our patients in the regions containing the three reported major mutations detected no sequence alterations of consequence. Our findings indicate that the NOD2/CARD15 gene is not a major contributor to CD susceptibility in the Japanese population.

Carrier Proteins↗

PubMed2002

Catalog of 86 single-nucleotide polymorphisms (SNPs) in three uridine diphosphate glycosyltransferase genes: UGT2A1, UGT2B15, and UGT8.

We report here three high-density maps of variations found among 48 Japanese individuals in three uridine diphosphate glycosyltransferase (UGT) genes, UGT2A1, UGT2B15, and UGT8. A total of 86 single-nucleotide polymorphisms (SNPs) were identified through systematic screening of genomic regions containing these genes: 8 in 5' flanking regions, 7 in coding regions, 67 in introns, 3 in 3' untranslated regions, and 1 in a 3' flanking region. We also discovered 14 variations of other types. Of the 86 SNPs, 63 (73%) were considered to be novel on the basis of comparison of our data with the Database of SNPs (dbSNP) of the National Center for Biotechnology Information. Among the seven SNPs identified in exonic sequences, five were non-synonymous changes that would result in amino-acid substitutions. The collection of SNPs derived from this study will serve as an additional resource for studies of complex genetic diseases and responsiveness to drug therapy.

Chromosome Mapping↗

PubMed2002

Single-nucleotide polymorphisms in the class II region of the major histocompatibility complex in Japanese patients with immunoglobulin A nephropathy.

Immunoglobulin A nephropathy (IgAN) is a form of chronic glomerulonephritis of unknown etiology and pathogenesis. Immunogenetic studies have not conclusively indicated that human leukocyte antigen (HLA) is involved. As a first step in investigating a possible relationship between HLA class II genes and IgAN, we analyzed the extent of linkage disequilibrium (LD) in this region of chromosome 6p21.3 in a Japanese test population and found extended LD blocks within the class II locus. We designed a case-control association study of single-nucleotide polymorphisms (SNPs) in each of those LD blocks, and determined that SNPs located in the HLA- DRA gene were significantly associated with an increased risk of IgAN ( P = 0.000001, odds ratio = 1.91 [95% confidence interval 1.46-2.49]); SNPs in other LD blocks were not. Our data imply that some haplotype of the HLA- DRA locus has an important role in the development of IgAN in Japanese patients.

Adult↗

PubMed2002

Catalog of 238 variations among six human genes encoding solute carriers ( hSLCs) in the Japanese population.

We screened DNAs of 48 Japanese individuals for single-nucleotide polymorphisms (SNPs) in six genes encoding proteins of the solute carrier (SLC) family by direct sequencing of their entire genomic regions except for repetitive-sequence elements. This approach identified 213 SNPs and 25 insertion/deletion polymorphisms among the six genes. On average, we identified 1 SNP in every 509 nucleotides. Of the 213 SNPs, 14 were identified in the SLC10A1 gene, 51 in SLC15A1, 29 in SLC22A1, 27 in SLC22A2, 54 in SLC22A4, and 38 in SLC22A5. Eight were located in 5' flanking regions, 172 in introns, 25 in exons, and 8 in 3' flanking regions. These variants should contribute to investigations of possible correlations between genotypes and phenotypes as regards disease susceptibilities or responsiveness to drug therapy.

Carrier Proteins↗

PubMed2002

Gene-based SNP discovery as part of the Japanese Millennium Genome Project: identification of 190,562 genetic variations in the human genome. Single-nucleotide polymorphism.

To construct an infrastructure for genome-wide association studies of common diseases or drug sensitivities, we have been systematically exploring common variants by resequencing genomic regions containing genes in DNA from 24 Japanese individuals. We have analyzed a total of 154 Mb, corresponding to approximately 5% of the human genome, and so far have identified 174,269 single-nucleotide polymorphisms and 16,293 insertion/deletion polymorphisms within gene regions, i.e., one polymorphism in 807 bp on average. Our data are freely available via our web site (http://snp.ims.u-tokyo.ac.jp) and will facilitate studies to identify genes associated with susceptibility to common diseases and genes involved in sensitivity to therapeutic drugs.

Gene Frequency↗

PubMed2002

Expression of Apc2 during mouse development.

APC2 (previously known as APCL), a molecule closely related to the adenomatous polyposis coli (APC) tumor suppressor, can deplete cytoplasmic beta-catenin, like APC itself. Recently, it has been shown that APC2 may regulate the localization of p53 and the microtubule stability and/or extension. Although it has been reported that APC2 mRNA is expressed in human brain, the anatomical and ontogenic expression patterns remain unclear. The purpose of this study was to investigate the distribution of mouse Apc2 during mouse development. In the adult brain, Apc2 is expressed predominantly in neurons and throughout the brain. Northern blot analysis demonstrated a high level of Apc2 expression in embryonic and early postnatal brain. Ontogenic analysis has indicated that Apc2 is expressed in neural tissue, including the peripheral nervous system. During development of cortex, retina and cerebellum, Apc2 is expressed in post-mitotic cells. These findings suggest that Apc2 may contribute to the development of neuronal cells.

Animals↗

PubMed2002

Prediction of sensitivity to STI571 among chronic myeloid leukemia patients by genome-wide cDNA microarray analysis.

One of the most critical issues to be solved in regard to cancer chemotherapy is the establishment of ways to predict the efficacy of anti-cancer drugs for individual patients. To develop a prediction system based on expression of specific genes, we analyzed expression profiles of mononuclear cells from 18 chronic myeloid leukemia (CML) patients who were treated with the tyrosine kinase inhibitor STI571. cDNA microarrays representing 23 040 genes identified 79 genes that were expressed differentially between responders and non-responders to STI571. On the basis of the expression patterns of 15 or 30 of these genes among the patients, we developed a "Prediction Score" system that could clearly separate the responder group from the non-responder group. Verification of this system using four additional ("test") cases succeeded in predicting the response of each of those four patients to the drug. These results provide the first evidence that gene-expression profiles can predict sensitivity of CML cells to STI571, and may eventually lead to the achievement of "personalized therapy" for this disease.

Adult↗

PubMed2002

Microarray analysis of gene-expression profiles in diffuse large B-cell lymphoma: identification of genes related to disease progression.

To identify genes that are associated with progression of malignant lymphoma, the expression profiles of 18,432 genes were analyzed in diffuse large B-cell lymphomas at early (stages I and II, 6 cases) and advanced stages (stages III and IV, 9 cases) by means of cDNA microarrays. By comparing expression profiles between localized and advanced lymphomas, a number of genes that were differentially expressed were identified: 48 genes with increased expression and 30 genes with reduced expression in advanced-stage diffuse large B-cell lymphomas. Increased expression of MPHOSPH1, RUVBL1, CHN2, PSA and CDC10 genes, and reduced expression of COL1A2, COL4A1, FBLN5, CLECSF6, MIC2, CAV1 and S100A10 genes in the advanced lymphoma group were confirmed by semi-quantitative reverse transcription-PCR. RUVBL1 and PSA expression was further confirmed by real-time quantitative PCR, whose results paralleled the microarray data. The highly expressed genes encode proteins that promote cell proliferation and the genes with reduced expression encode adhesion proteins and target protein for cytotoxic T-lymphocytes. These findings suggested that analysis with cDNA microarrays is a useful approach for identifying genes related to tumor progression and their products could be potential tumor markers or disease-specific targets for anti-tumor therapy.

Adult↗

PubMed2002

Involvement of FKHR-dependent TRADD expression in chemotherapeutic drug-induced apoptosis.

Chemotherapeutic drugs exhibit their cytotoxic effect by inducing apoptosis in tumor cells. Because the serine/threonine kinase Akt is involved in apoptosis suppression, we investigated the relationship between Akt activity and drug sensitivity. We discovered that certain chemotherapeutic drugs induced apoptosis with caspase activation only when Akt was inactivated after drug treatment, while inactivation of Akt was not observed when tumor cells showed resistance to the drug-induced caspase activation. So, turn-off of the Akt-mediated survival signal is correlated with the sensitivity of the cells to chemotherapy. With a cDNA microarray, we revealed that tumor necrosis factor receptor-associated death domain (tradd) gene expression was elevated in response to Akt inactivation. Reportedly, Forkhead family transcription factors are phosphorylated by Akt, which results in their nuclear exit and inactivation. Analysis of the tradd promoter revealed that it contains at least one potential Forkhead family transcription factor-responsive element, and we confirmed that this element was involved in chemotherapeutic drug-induced TRADD expression. Overexpression of mutant TRADD proteins to block its apoptosis-inducing capability attenuated chemotherapeutic drug-induced apoptosis. Thus, chemotherapeutic drugs exhibited their cytotoxic effects in part by down-regulating Akt signaling following TRADD expression. These results indicate that Akt kinase activity after drug treatment is a hallmark of sensitivity of the cells to chemotherapeutic drugs.

3-Phosphoinositide-Dependent Protein Kinases↗