論文 - 宮　冬樹

A combination of targeted enrichment methodologies for whole-exome sequencing reveals novel pathogenic mutations.

Miya F, Kato M, Shiohama T, Okamoto N, Saitoh S, Yamasaki M, Shigemizu D, Abe T, Morizono T, Boroevich KA, Kosaki K, Kanemura Y, Tsunoda T

Scientific reports （Scientific Reports）  5   9331 2015年03月

　概要を見る

Whole-exome sequencing (WES) is a useful method to identify disease-causing mutations, however, often no candidate mutations are identified using commonly available targeted probe sets. In a recent analysis, we also could not find candidate mutations for 20.9% (9/43) of our pedigrees with congenital neurological disorder using pre-designed capture probes (SureSelect V4 or V5). One possible cause for this lack of candidates is that standard WES cannot sequence all protein-coding sequences (CDS) due to capture probe design and regions of low coverage, which account for approximately 10% of all CDS regions. In this study, we combined a selective circularization-based target enrichment method (HaloPlex) with a hybrid capture method (SureSelect V5; WES), and achieved a more complete coverage of CDS regions (∼97% of all CDS). We applied this approach to 7 (SureSelect V5) out of 9 pedigrees with no candidates through standard WES analysis and identified novel pathogenic mutations in one pedigree. The application of this effective combination of targeted enrichment methodologies can be expected to aid in the identification of novel pathogenic mutations previously missed by standard WES analysis.

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A genome-wide association study identifies PLCL2 and AP3D1-DOT1L-SF3A2 as new susceptibility loci for myocardial infarction in Japanese.

Hirokawa M, Morita H, Tajima T, Takahashi A, Ashikawa K, Miya F, Shigemizu D, Ozaki K, Sakata Y, Nakatani D, Suna S, Imai Y, Tanaka T, Tsunoda T, Matsuda K, Kadowaki T, Nakamura Y, Nagai R, Komuro I, Kubo M

European journal of human genetics : EJHG （European Journal of Human Genetics）  23 （ 3 ） 374 - 80 2015年03月

ISSN  1018-4813

　概要を見る

Despite considerable progress in preventive and therapeutic strategies, myocardial infarction (MI) is one of the leading causes of death throughout the world. A total of 55 susceptibility genes have been identified mostly in European genome-wide association studies (GWAS). Nevertheless, large-scale GWAS from other population could possibly find additional susceptibility loci. To identify as many MI susceptibility loci as possible, we performed a large-scale genomic analysis in Japanese population. To identify MI susceptibility loci in Japanese, we conducted a GWAS using 1666 cases and 3198 controls using the Illumina Human610-Quad BeadChip and HumanHap550v3 Genotyping BeadChip. We performed replication studies using a total of 11 412 cases and 28 397 controls in the Japanese population. Our study identified two novel susceptibility loci for MI: PLCL2 on chromosome 3p24.3 (rs4618210:A>G, P=2.60 × 10 -9, odds ratio (OR)=0.91) and AP3D1-DOT1L-SF3A2 on chromosome 19p13.3 (rs3803915:A>C, P=3.84 × 10 -9, OR=0.89). Besides, a total of 14 previously reported MI susceptibility loci were replicated in our study. In particular, we validated a strong association on chromosome 12q24 (rs3782886:A>G: P=1.14 × 10 -14, OR=1.46). Following pathway analysis using 265 genes related to MI or coronary artery disease, we found that these loci might be involved in the pathogenesis of MI via the promotion of atherosclerosis. In the present large-scale genomic analysis, we identified PLCL2 and AP3D1-DOT1L-SF3A2 as new susceptibility loci for MI in the Japanese population. Our findings will add novel findings for MI susceptibility loci.

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Sudden death in a case of megalencephaly capillary malformation associated with a de novo mutation in AKT3.

Harada A, Miya F, Utsunomiya H, Kato M, Yamanaka T, Tsunoda T, Kosaki K, Kanemura Y, Yamasaki M

Child's nervous system : ChNS : official journal of the International Society for Pediatric Neurosurgery （Child's Nervous System）  31 （ 3 ） 465 - 71 2015年03月

ISSN  0256-7040

　概要を見る

Introduction: Megalencephaly capillary malformation (MCAP) is a syndrome involving brain overgrowth, characterized by megalencephaly, capillary malformations, asymmetric growth, polymicrogyria, polydactyly, and syndactyly. Cerebellar tonsillar herniation (CTH) and ventriculomegaly are also observed in over half the patients with this syndrome. Early sudden death has been reported in MCAP, but its causes and the surgical strategies for its prevention remain unclear.

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Attenuation of progressive hearing loss in DBA/2J mice by reagents that affect epigenetic modifications is associated with up-regulation of the zinc importer Zip4.

Mutai H, Miya F, Fujii M, Tsunoda T, Matsunaga T

PloS one （PLoS ONE）  10 （ 4 ） e0124301 2015年

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Various factors that are important for proper hearing have been identified, including serum levels of zinc. Here we investigated whether epigenetic regulatory pathways, which can be modified by environmental factors, could modulate hearing. RT-PCR detected expression of genes encoding DNA methyltransferase and histone deacetylase (Hdac) in the postnatal as well as adult mouse auditory epithelium. DBA/2J mice, which are a model for progressive hearing loss, were injected subcutaneously with one or a combination of the following reagents: 〈smallcaps〉L〈/smallcaps〉-methionine as a methyl donor, valproic acid as a pan-Hdac inhibitor, and folic acid and vitamin B12 as putative factors involved in age-related hearing loss. The mice were treated from ages 4 to 12 weeks (N ≥ 5), and auditory brainstem response (ABR) thresholds were measured at 8, 16, and 32 kHz. Treatment of the mice with a combination of 〈smallcaps〉L〈/smallcaps〉-methionine and valproic acid (M+V) significantly reduced the increase in the ABR threshold at 32 kHz. Treatment with any of these reagents individually produced no such effect. Microarray analyses detected 299 gene probes that were significantly up- or down-regulated in the cochleae of mice treated with M+V compared with the control vehicle-treated mice. Quantitative RT-PCR confirmed significant up-regulation of a zinc importer gene, Zip4, in the cochleae of mice treated with M+V. Immunohistochemistry demonstrated an intense Zip4 signal in cochlear tissues such as the lateral wall, organ of Corti, and spiral ganglion. Finally, mice treated with the Zip4 inducer (-)-epigallocatechin-3-O-gallate showed a significant reduction in the increase of the ABR threshold at 32 kHz and up-regulation of Zip4 expression in the cochlea. This study suggests that epigenetic regulatory pathways can modify auditory function and that zinc intake in the cochlea via Zip4 mediates maintenance of mammalian hearing.

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Truncating mutation in NFIA causes brain malformation and urinary tract defects.

Negishi Y, Miya F, Hattori A, Mizuno K, Hori I, Ando N, Okamoto N, Kato M, Tsunoda T, Yamasaki M, Kanemura Y, Kosaki K, Saitoh S

Human genome variation 2   15007 2015年

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Exome Analyses of Long QT Syndrome Reveal Candidate Pathogenic Mutations in Calmodulin-Interacting Genes.

Shigemizu D, Aiba T, Nakagawa H, Ozaki K, Miya F, Satake W, Toda T, Miyamoto Y, Fujimoto A, Suzuki Y, Kubo M, Tsunoda T, Shimizu W, Tanaka T

PloS one （PLoS ONE）  10 （ 7 ） e0130329 2015年

　概要を見る

Long QT syndrome (LQTS) is an arrhythmogenic disorder that can lead to sudden death. To date, mutations in 15 LQTS-susceptibility genes have been implicated. However, the genetic cause for approximately 20% of LQTS patients remains elusive. Here, we performed whole-exome sequencing analyses on 59 LQTS and 61 unaffected individuals in 35 families and 138 unrelated LQTS cases, after genetic screening of known LQTS genes. Our systematic analysis of familial cases and subsequent verification by Sanger sequencing identified 92 candidate mutations in 88 genes for 23 of the 35 families (65.7%): these included eleven de novo, five recessive (two homozygous and three compound heterozygous) and seventy-three dominant mutations. Although no novel commonly mutated gene was identified other than known LQTS genes, protein-protein interaction (PPI) network analyses revealed ten new pathogenic candidates that directly or indirectly interact with proteins encoded by known LQTS genes. Furthermore, candidate gene based association studies using an independent set of 138 unrelated LQTS cases and 587 controls identified an additional novel candidate. Together, mutations in these new candidates and known genes explained 37.1% of the LQTS families (13 in 35). Moreover, half of the newly identified candidates directly interact with calmodulin (5 in 11; comparison with all genes; p=0.042). Subsequent variant analysis in the independent set of 138 cases identified 16 variants in the 11 genes, of which 14 were in calmodulin-interacting genes (87.5%). These results suggest an important role of calmodulin and its interacting proteins in the pathogenesis of LQTS.

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KIF1A mutation in a patient with progressive neurodegeneration.

Okamoto N, Miya F, Tsunoda T, Yanagihara K, Kato M, Saitoh S, Yamasaki M, Kanemura Y, Kosaki K

Journal of human genetics （Journal of Human Genetics）  59 （ 11 ） 639 - 41 2014年11月

ISSN  1434-5161

　概要を見る

Kinesins are a large superfamily of molecular motors. They move along microtubule filaments and are powered by the hydrolysis of ATP. This transport system is essential for neuronal function and survival. KIF1A belongs to the kinesin 3 family and involves in the anterograde transport of synaptic vesicle precursors along axons. Several studies confirmed that KIF1A mutations cause spastic paraplegia and sensory neuropathy in an autosomal-recessive fashion. A missense mutation in the KIF1A gene (p.Thr99Met) has been reported in a patient with intellectual disability (ID), axial hypotonia and peripheral spasticity. Mild atrophy of the cerebellar vermis was found on magnetic resonance imaging. The mutation was heterozygous and de novo. We identified the second patient with the p.T99M mutation in the KIF1A gene by whole-exome sequencing. He showed severe ID, spasticity, optic atrophy, neurogenic bladder, growth failure and progressive cerebellar atrophy. The p.T99M mutation may be a common recurrent mutation. We suppose that this specific mutation of KIF1A shows a novel neurodegenerative syndrome.

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Morphological and microarray analyses of human hepatocytes from xenogeneic host livers.

Tateno C, Miya F, Wake K, Kataoka M, Ishida Y, Yamasaki C, Yanagi A, Kakuni M, Wisse E, Verheyen F, Inoue K, Sato K, Kudo A, Arii S, Itamoto T, Asahara T, Tsunoda T, Yoshizato K

Laboratory investigation; a journal of technical methods and pathology （Laboratory Investigation）  93 （ 1 ） 54 - 71 2013年01月

ISSN  0023-6837

　概要を見る

We previously produced mice with human hepatocyte (h-hep) chimeric livers by transplanting h-heps into albumin enhancer/promoter-driven urokinase-type plasminogen activator-transgenic severe combined immunodeficient (SCID) mice with liver disease. The chimeric livers were constructed with h-heps, mouse hepatocytes, and mouse hepatic sinusoidal cells (m-HSCs). Here, we investigated the morphological features of the chimeric livers and the h-hep gene expression profiles in the xenogeneic animal body. To do so, we performed immunohistochemistry, morphometric analyses, and electron microscopic observations on chimeric mouse livers, and used microarray analyses to compare gene expression patterns in hepatocytes derived from chimeric mouse hepatocytes (c-heps) and h-heps. Morphometric analysis revealed that the ratio of hepatocytes to m-HSCs in the chimeric mouse livers were twofold higher than those in the SCID mouse livers, corresponding to twin-cell plates in the chimeric mouse liver. The h-heps in the chimeric mouse did not show hypoxia even in the twin-cell plate structure, probably because of low oxygen consumption by the h-heps relative to the mouse hepatocytes (m-heps). Immunohistochemical and electron microscopic examinations revealed that the sinusoids in the chimeric mouse livers were normally constructed with h-heps and m-HSCs. However, a number of microvilli projected into the intercellular clefts on the lateral aspects of the hepatocytes, features typical of a growth phase. Microarray profiles indicated that ∼82% of 16 605 probes were within a twofold range difference between h-heps and c-heps. Cluster and principal component analyses showed that the gene expression patterns of c-heps were extremely similar to those of h-heps. In conclusion, the chimeric mouse livers were normally reconstructed with h-heps and m-HSCs, and expressed most human genes at levels similar to those in human livers, although the chimeric livers showed morphological characteristics typical of growth. © 2013 USCAP, Inc All rights reserved.

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Whole-genome sequencing of liver cancers identifies etiological influences on mutation patterns and recurrent mutations in chromatin regulators.

Fujimoto A, Totoki Y, Abe T, Boroevich KA, Hosoda F, Nguyen HH, Aoki M, Hosono N, Kubo M, Miya F, Arai Y, Takahashi H, Shirakihara T, Nagasaki M, Shibuya T, Nakano K, Watanabe-Makino K, Tanaka H, Nakamura H, Kusuda J, Ojima H, Shimada K, Okusaka T, Ueno M, Shigekawa Y, Kawakami Y, Arihiro K, Ohdan H, Gotoh K, Ishikawa O, Ariizumi S, Yamamoto M, Yamada T, Chayama K, Kosuge T, Yamaue H, Kamatani N, Miyano S, Nakagama H, Nakamura Y, Tsunoda T, Shibata T, Nakagawa H

Nature genetics （Nature Genetics）  44 （ 7 ） 760 - 4 2012年05月

ISSN  1061-4036

　概要を見る

Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related death worldwide. We sequenced and analyzed the whole genomes of 27 HCCs, 25 of which were associated with hepatitis B or C virus infections, including two sets of multicentric tumors. Although no common somatic mutations were identified in the multicentric tumor pairs, their whole-genome substitution patterns were similar, suggesting that these tumors developed from independent mutations, although their shared etiological backgrounds may have strongly influenced their somatic mutation patterns. Statistical and functional analyses yielded a list of recurrently mutated genes. Multiple chromatin regulators, including ARID1A, ARID1B, ARID2, MLL and MLL3, were mutated in ∼50% of the tumors. Hepatitis B virus genome integration in the TERT locus was frequently observed in a high clonal proportion. Our whole-genome sequencing analysis of HCCs identified the influence of etiological background on somatic mutation patterns and subsequent carcinogenesis, as well as recurrent mutations in chromatin regulators in HCCs. © 2012 Nature America, Inc. All rights reserved.

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Growth hormone-dependent pathogenesis of human hepatic steatosis in a novel mouse model bearing a human hepatocyte-repopulated liver.

Tateno C, Kataoka M, Utoh R, Tachibana A, Itamoto T, Asahara T, Miya F, Tsunoda T, Yoshizato K

Endocrinology （Endocrinology）  152 （ 4 ） 1479 - 91 2011年04月

ISSN  0013-7227

　概要を見る

Clinical studies have shown a close association between nonalcoholic fatty liver disease and adult-onset GH deficiency, but the relevant molecular mechanisms are still unclear. No mouse model has been suitable to study the etiological relationship ofhumannonalcoholic fatty liver disease and human adult-onset GH deficiency under conditions similar to the human liver in vivo. We generated human (h-)hepatocyte chimeric mice with livers that were predominantly repopulated with h-hepatocytes in a h-GH-deficient state. The chimeric mouse liver was mostly repopulated with h-hepatocytes about 50 d after transplantation and spontaneously became fatty in the h-hepatocyte regions after about 70 d. Infusion of the chimeric mouse with h-GH drastically decreased steatosis, showing the direct cause ofh-GH deficiency in the generation of hepatic steatosis. Using microarray profiles aided by real-time quantitative RT-PCR, comparison between h-hepatocytes from h-GH-untreated and -treated mice identified 14 GH-up-regulated and four GH-down-regulated genes, including IGF-I, SOCS2, NNMT, IGFLS, P4AH1, SLC16A1, SRD5A1, FADS1, and AKR1B10, respectively. These GH-up- and -down-regulated genes were expressed in the chimeric mouse liver at lower and higher levels than in human livers, respectively. Treatment of the chimeric mice with h-GH ameliorated their altered expression. h-Hepatocytes were separated from chimeric mouse livers for testing in vitro effects of h-GH or h-IGF-I on gene expression, and results showed that GH directly regulated the expression of IGF-I, SOCS2, NNMT, IGFALS, P4AH1, FADS1, and AKR1B10. In conclusion, the chimeric mouse is a novel h-GH-deficient animal model for studying in vivo h-GH-dependent human liver dysfunctions. Copyright © 2011 by The Endocrine Society.

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Predicting response of bladder cancers to gemcitabine and carboplatin neoadjuvant chemotherapy through genome-wide gene expression profiling.

Kato Y, Zembutsu H, Takata R, Miya F, Tsunoda T, Obara W, Fujioka T, Nakamura Y

Experimental and therapeutic medicine （Experimental and Therapeutic Medicine）  2 （ 1 ） 47 - 56 2011年01月

ISSN  1792-0981

　概要を見る

Neoadjuvant chemotherapy with gemcitabine and carboplatin (GC) for invasive bladder cancer increases the chance of a radical response for a subset of patients, while other patients suffer from severe adverse drug reactions without any benefit. To establish a method for predicting the response to chemotherapy with GC, the expression profiles of biopsy samples from 37 advanced bladder cancers were analyzed using a microarray consisting of 38,500 genes or ESTs. Upon analysis of 9 'responder' and 9 'non-responder' tumors, 12 'predictive' genes were found to be significantly differentially expressed between the 'responder' and 'non-responder' groups, and a numerical prediction scoring system that clearly separated the responder group from the non-responder group was established. This system accurately predicted the drug responses of 18 of 19 additional test cases that were reserved from the original 37 cases. Moreover, a quantitative PCR-based prediction system was developed that may be feasible for routine clinical use, and the sensitivity of invasive bladder cancer to neoadjuvant chemotherapy with GC was able to be predicted by the expression patterns in this set of genes. Nearly 50% of patients treated with GC or methotrexate, vinblastine, doxorubicin and cisplatin (M-VAC) therapy have been reported to achieve complete or partial response to either of these therapies. When we applied this prediction system as well as the system for M-VAC, we expected that approximately 80% of the patients would achieve significant tumor shrinking (>60%) by selection of either the GC or M-VAC regimens. Our results suggest that the two prediction scoring systems lead to achievement of 'personalized therapy' for the treatment of invasive bladder cancer and should improve the quality of life for patients with this disease.

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Hepatitis C virus infection suppresses the interferon response in the liver of the human hepatocyte chimeric mouse.

Tsuge M, Fujimoto Y, Hiraga N, Zhang Y, Ohnishi M, Kohno T, Abe H, Miki D, Imamura M, Takahashi S, Ochi H, Hayes CN, Miya F, Tsunoda T, Chayama K

PloS one （PLoS ONE）  6 （ 8 ） e23856 2011年

　概要を見る

Background and Aims: Recent studies indicate that hepatitis C virus (HCV) can modulate the expression of various genes including those involved in interferon signaling, and up-regulation of interferon-stimulated genes by HCV was reported to be strongly associated with treatment outcome. To expand our understanding of the molecular mechanism underlying treatment resistance, we analyzed the direct effects of interferon and/or HCV infection under immunodeficient conditions using cDNA microarray analysis of human hepatocyte chimeric mice. Methods: Human serum containing HCV genotype 1b was injected into human hepatocyte chimeric mice. IFN-α was administered 8 weeks after inoculation, and 6 hours later human hepatocytes in the mouse livers were collected for microarray analysis. Results: HCV infection induced a more than 3-fold change in the expression of 181 genes, especially genes related to Organismal Injury and Abnormalities, such as fibrosis or injury of the liver (P = 5.90E-16 ~ 3.66E-03). IFN administration induced more than 3-fold up-regulation in the expression of 152 genes. Marked induction was observed in the anti-fibrotic chemokines such as CXCL9, suggesting that IFN treatment might lead not only to HCV eradication but also prevention and repair of liver fibrosis. HCV infection appeared to suppress interferon signaling via significant reduction in interferon-induced gene expression in several genes of the IFN signaling pathway, including Mx1, STAT1, and several members of the CXCL and IFI families (P = 6.0E-12). Genes associated with Antimicrobial Response and Inflammatory Response were also significantly repressed (P = 5.22×10 -10 ~ 1.95×10 -2). Conclusions: These results provide molecular insights into possible mechanisms used by HCV to evade innate immune responses, as well as novel therapeutic targets and a potential new indication for interferon therapy. © 2011 Tsuge et al.

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Identification of a set of genes associated with response to interleukin-2 and interferon-α combination therapy for renal cell carcinoma through genome-wide gene expression profiling.

Mizumori O, Zembutsu H, Kato Y, Tsunoda T, Miya F, Morizono T, Tsukamoto T, Fujioka T, Tomita Y, Kitamura T, Ozono S, Miki T, Naito S, Akaza H, Nakamura Y

Experimental and therapeutic medicine （Experimental and Therapeutic Medicine）  1 （ 6 ） 955 - 961 2010年11月

ISSN  1792-0981

　概要を見る

Interleukin (IL)-2 and interferon (IFN)-α combination therapy for metastatic renal cell carcinoma (RCC) improves the prognosis for a subset of patients, while some patients suffer from severe adverse drug reactions with little benefit. To establish a method to predict responses to this combination therapy (approximately 30% response rate), the gene expression profiles of primary RCCs were analyzed using an oligo DNA microarray consisting of 38,500 genes or ESTs, after enrichment of the cancer cell population by laser microbeam microdissection. The analysis of 10 responders and 18 non-responders identified 24 genes that exhibited significant differential expression between the two groups. In addition, the patients whose tumors did not express HLA-DQA1 or HLA-DQB1 molecules demonstrated poor clinical response. Exclusion of patients with tumors lacking either of these two genes is likely to improve the response rate to IL-2 and IFN-α combination therapy from 30 to 67%, indicating that a simple pretreatment test provides useful information with which to subselect patients with renal cancer in order to improve the efficacy of this treatment and reduce unnecessary medical costs.

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C-MYC overexpression with loss of Ink4a/Arf transforms bone marrow stromal cells into osteosarcoma accompanied by loss of adipogenesis

Shimizu T., Ishikawa T., Sugihara E., Kuninaka S., Miyamoto T., Mabuchi Y., Matsuzaki Y., Tsunoda T., Miya F., Morioka H., Nakayama R., Kobayashi E., Toyama Y., Kawai A., Ichikawa H., Hasegawa T., Okada S., Ito T., Ikeda Y., Suda T., Saya H.

Oncogene （Oncogene）  29 （ 42 ） 5687 - 5699 2010年10月

ISSN  09509232

　概要を見る

The development of cancer is due to the growth and proliferation of transformed normal cells. Recent evidence suggests that the nature of oncogenic stress and the state of the cell of origin critically affect both tumorigenic activity and tumor histological type. However, this mechanistic relationship in mesenchymal tumors is currently largely unexplored. To clarify these issues, we established a mouse osteosarcoma (OS) model through overexpression of c-MYC in bone marrow stromal cells (BMSCs) derived from Ink4a/Arf (/) mice. Single-cell cloning revealed that c-MYC-expressing BMSCs are composed of two distinctly different clones: highly tumorigenic cells, similar to bipotent-committed osteochondral progenitor cells, and low-tumorigenic tripotent cells, similar to mesenchymal stem cells (MSCs). It is noteworthy that both bipotent and tripotent cells were capable of generating histologically similar, lethal OS, suggesting that both committed progenitor cells and MSCs can become OS cells of origin. Shifting mesenchymal differentiation by depleting PPARγ in tripotent MSC-like cells and overexpressing PPARγ in bipotent cells affected cell proliferation and tumorigenic activity. Our findings indicate that differentiation potential has a key role in OS tumorigenic activity, and that the suppression of adipogenic ability is a critical factor for the development of OS. © 2010 Macmillan Publishers Limited All rights reserved.

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Recombination rates of genes expressed in human tissues.

Kato M, Miya F, Kanemura Y, Tanaka T, Nakamura Y, Tsunoda T

Human molecular genetics （Human Molecular Genetics）  17 （ 4 ） 577 - 86 2008年02月

ISSN  0964-6906

　概要を見る

High-resolution recombination rates have recently been revealed in the human genome, and considerable variation in patterns of recombination rates has been found along the chromosomes. Although the associations between this variation and genomic sequence features, such as genic regions, provide information on haplotype diversity and natural selection in these regions, the associations are not well understood. Here, we performed microarray experiments to identify genes specifically expressed in human tissues and investigated tendencies of recombination rates within tissue-specific genes. We found that some types of tissue-specific genes (in the frontal lobe, fetal brain, testis, thymus and thyroid) tended to have extremely low recombination rates, whereas other types (in the brain cerebellum, brain whole, stomach, lung and bone marrow) tended to have relatively high recombination rates. Surprisingly, genes specifically expressed in the frontal lobe, which is a brain region involved in human cognitive abilities, had low recombination rates, whereas genes specifically expressed in the cerebellum, which is a brain region with primitive functions shared by all vertebrate species, had high rates. These findings suggest that natural selection forms the recombination rate tendencies according to the physiological functions exerted in the tissues. For example, the low recombination rates in frontal lobe-specific genes may indicate that a few haplotypes have been rapidly widespread across the population because higher cognitive abilities are advantageous. Frontal lobe-specific genes with extremely low recombination rates may be candidates for genes related to cognitive abilities that human species have recently obtained. © 2007 The Author(s).

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Pravastatin at 10 mg/day does not decrease plasma levels of either amyloid-beta (Abeta) 40 or Abeta 42 in humans.

Ishii K, Tokuda T, Matsushima T, Miya F, Shoji S, Ikeda S, Tamaoka A

Neuroscience letters （Neuroscience Letters）  350 （ 3 ） 161 - 4 2003年10月

ISSN  0304-3940

　概要を見る

It has been assumed that statins work as a preventative drug for Alzheimer's disease (AD). Although some epidemiological observations raise doubts to the effectiveness of statins for AD, many in vitro and clinical studies insist on the effectiveness of statins decreasing amyloid-β (Aβ) levels in medium or blood. To explore the effect of pravastatin on Aβ production, we followed the longitudinal plasma levels of both Aβ 40 and Aβ 42 during the allocation of pravastatin in 46 patients with hyperlipidemia. We found no correlation between plasma cholesterol levels or the decreasing values of total cholesterol and those of Aβ 40 or Aβ 42. Patients having Apolipoprotein E4 (ApoE4) had higher low-density lipoprotein levels and lower Aβ 40 levels in plasma, suggesting ApoE4 seems to influence plasma Aβ levels via cholesterol metabolism. © 2003 Elsevier Ireland Ltd. All rights reserved.

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Molecular cloning of ubiquitin-activating enzyme (E1) from Xenopus laevis

Miya F., Tokumoto M., Nagahama Y., Okida N., Ishikawa K., Tokumoto T.

Mitochondrial DNA （Mitochondrial DNA）  11 （ 3-4 ） 349 - 352 2000年12月

ISSN  19401736

　概要を見る

The Xenopus homologue to the ubiquitin-activating enzyme (El) from a Xenopus ovary is described. The deduced amino acid sequence is highly homologous to El from other species. © 2000 OPA (Overseas Publishers Association) N.V.

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