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Abstract
CRISPR/Cas enables rapid production of genome-edited animals. The Cas9/gRNA component can be introduced to fertilized eggs in several ways. Here, we provide an instructional guide for the generation of knockout mice by cytoplasmic injection using in vitro transcribed Cas9 and gRNA.
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Morita S, Noguchi H, Horii T, Nakabayashi K, Kimura M, Okamura K, Sakai A, Nakashima H, Hata K, Nakashima K, Hatada I. Targeted DNA demethylation in vivo using dCas9-peptide repeat and scFv-TET1 catalytic domain fusions. Nat Biotechnol 2016; 34:1060-1065. [PMID: 27571369 DOI: 10.1038/nbt.3658] [Citation(s) in RCA: 317] [Impact Index Per Article: 39.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Accepted: 07/28/2016] [Indexed: 12/19/2022]
Abstract
Despite the importance of DNA methylation in health and disease, technologies to readily manipulate methylation of specific sequences for functional analysis and therapeutic purposes are lacking. Here we adapt the previously described dCas9-SunTag for efficient, targeted demethylation of specific DNA loci. The original SunTag consists of ten copies of the GCN4 peptide separated by 5-amino-acid linkers. To achieve efficient recruitment of an anti-GCN4 scFv fused to the ten-eleven (TET) 1 hydroxylase, which induces demethylation, we changed the linker length to 22 amino acids. The system attains demethylation efficiencies >50% in seven out of nine loci tested. Four of these seven loci showed demethylation of >90%. We demonstrate targeted demethylation of CpGs in regulatory regions and demethylation-dependent 1.7- to 50-fold upregulation of associated genes both in cell culture (embryonic stem cells, cancer cell lines, primary neural precursor cells) and in vivo in mouse fetuses.
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Abstract
Vertebrate genomes are highly methylated at cytosine residues in CpG sequences. CpG
methylation plays an important role in epigenetic gene silencing and genome stability.
Compared with other epigenetic modifications, CpG methylation is thought to be relatively
stable; however, it is sometimes affected by environmental changes, leading to epigenetic
instability and disease. CpG methylation is reversible and regulated by DNA
methyltransferases and demethylases including ten-eleven translocation. Here, we discuss
CpG methylation instability and the regulation of CpG methylation by DNA
methyltransferases and ten-eleven translocation in pluripotent stem cells.
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Hirano H, Gootenberg JS, Horii T, Abudayyeh OO, Kimura M, Hsu PD, Nakane T, Ishitani R, Hatada I, Zhang F, Nishimasu H, Nureki O. Structure and Engineering of Francisella novicida Cas9. Cell 2016; 164:950-61. [PMID: 26875867 PMCID: PMC4899972 DOI: 10.1016/j.cell.2016.01.039] [Citation(s) in RCA: 229] [Impact Index Per Article: 28.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Revised: 01/20/2016] [Accepted: 01/25/2016] [Indexed: 12/26/2022]
Abstract
The RNA-guided endonuclease Cas9 cleaves double-stranded DNA targets complementary to the guide RNA and has been applied to programmable genome editing. Cas9-mediated cleavage requires a protospacer adjacent motif (PAM) juxtaposed with the DNA target sequence, thus constricting the range of targetable sites. Here, we report the 1.7 Å resolution crystal structures of Cas9 from Francisella novicida (FnCas9), one of the largest Cas9 orthologs, in complex with a guide RNA and its PAM-containing DNA targets. A structural comparison of FnCas9 with other Cas9 orthologs revealed striking conserved and divergent features among distantly related CRISPR-Cas9 systems. We found that FnCas9 recognizes the 5'-NGG-3' PAM, and used the structural information to create a variant that can recognize the more relaxed 5'-YG-3' PAM. Furthermore, we demonstrated that the FnCas9-ribonucleoprotein complex can be microinjected into mouse zygotes to edit endogenous sites with the 5'-YG-3' PAM, thus expanding the target space of the CRISPR-Cas9 toolbox.
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Morita S, Nakabayashi K, Kawai T, Hayashi K, Horii T, Kimura M, Kamei Y, Ogawa Y, Hata K, Hatada I. Gene expression profiling of white adipose tissue reveals paternal transmission of proneness to obesity. Sci Rep 2016; 6:21693. [PMID: 26868178 PMCID: PMC4751506 DOI: 10.1038/srep21693] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Accepted: 01/29/2016] [Indexed: 11/21/2022] Open
Abstract
Previously, we found that C57BL/6J (B6) mice are more prone to develop obesity than PWK mice. In addition, we analyzed reciprocal crosses between these mice and found that (PWK × B6) F1 mice, which have B6 fathers, are more likely to develop dietary obesity than (B6 × PWK) F1 mice, which have B6 mothers. These results suggested that diet-induced obesity is paternally transmitted. In this study, we performed transcriptome analysis of adipose tissues of B6, PWK, (PWK × B6) F1, and (B6 × PWK) F1 mice using next-generation sequencing. We found that paternal transmission of diet-induced obesity was correlated with genes involved in adipose tissue inflammation, metal ion transport, and cilia. Furthermore, we analyzed the imprinted genes expressed in white adipose tissue (WAT) and obesity. Expression of paternally expressed imprinted genes (PEGs) was negatively correlated with body weight, whereas expression of maternally expressed imprinted genes (MEGs) was positively correlated. In the obesity-prone B6 mice, expression of PEGs was down-regulated by a high-fat diet, suggesting that abnormally low expression of PEGs contributes to high-fat diet-induced obesity in B6 mice. In addition, using single-nucleotide polymorphisms that differ between B6 and PWK, we identified candidate imprinted genes in WAT.
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Kafer GR, Li X, Horii T, Suetake I, Tajima S, Hatada I, Carlton PM. 5-Hydroxymethylcytosine Marks Sites of DNA Damage and Promotes Genome Stability. Cell Rep 2016; 14:1283-1292. [PMID: 26854228 DOI: 10.1016/j.celrep.2016.01.035] [Citation(s) in RCA: 124] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Revised: 10/03/2015] [Accepted: 01/08/2016] [Indexed: 01/05/2023] Open
Abstract
5-hydroxymethylcytosine (5hmC) is a DNA base created during active DNA demethylation by the recently discovered TET enzymes. 5hmC has essential roles in gene expression and differentiation. Here, we demonstrate that 5hmC also localizes to sites of DNA damage and repair. 5hmC accumulates at damage foci induced by aphidicolin and microirradiation and colocalizes with major DNA damage response proteins 53BP1 and γH2AX, revealing 5hmC as an epigenetic marker of DNA damage. Deficiency for the TET enzymes eliminates damage-induced 5hmC accumulation and elicits chromosome segregation defects in response to replication stress. Our results indicate that the TET enzymes and 5hmC play essential roles in ensuring genome integrity.
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Abstract
Genome editing technologies represent a major breakthrough that has dramatically altered strategies in a wide range of biological studies. Genome editing simplifies and accelerates the creation of animal disease models and enables construction of models in most animal species, even those that are not amenable to conventional gene targeting technology.
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Abstract
Clustered regularly at interspaced short palindromic repeats (CRISPR) and CRISPR-associated (Cas) nucleases, so-called CRISPR/Cas, was recently developed as an epoch-making genome engineering technology. This system only requires Cas9 nuclease and single-guide RNA complementary to a target locus. CRISPR/Cas enables the generation of knockout cells and animals in a single step. This system can also be used to generate multiple mutations and knockin in a single step, which is not possible using other methods. In this review, we provide an overview of genome editing by CRISPR/Cas in pluripotent stem cells and mice.
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Abstract
Gene targeting technologies are essential for the analysis of gene functions. Knockout mouse generation via
genetic modification of embryonic stem cells (ESCs) is the commonest example, but it is a time-consuming and
labor-intensive procedure. Recently, a novel genome editing technology called CRISPR/Cas has enabled the
direct production of knockout mice by non-homologous end joining (NHEJ)-mediated mutations. Unexpectedly,
however, it generally exhibits a low efficiency in homologous recombination (HR) and is prone to high
mosaicism. Meanwhile, gene targeting using ESCs is still being improved, as reported by Fukuda et
al. in this issue. Here, we outline current gene targeting technologies with special emphasis on
HR-mediated technologies, which are currently being performed using these two major strategies.
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Horii T, Yamamoto M, Morita S, Kimura M, Nagao Y, Hatada I. p53 suppresses tetraploid development in mice. Sci Rep 2015; 5:8907. [PMID: 25752699 PMCID: PMC4354145 DOI: 10.1038/srep08907] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Accepted: 02/09/2015] [Indexed: 11/09/2022] Open
Abstract
Mammalian tetraploid embryos die in early development because of defects in the epiblast. Experiments with diploid/tetraploid chimeric mice, obtained via the aggregation of embryonic stem cells, clarified that while tetraploid cells are excluded from epiblast derivatives, diploid embryos with tetraploid extraembryonic tissues can develop to term. Today, this method, known as tetraploid complementation, is usually used for rescuing extraembryonic defects or for obtaining completely embryonic stem (ES) cell-derived pups. However, it is still unknown why defects occur in the epiblast during mammalian development. Here, we demonstrated that downregulation of p53, a tumour suppressor protein, rescued tetraploid development in the mammalian epiblast. Tetraploidy in differentiating epiblast cells triggered p53-dependent cell-cycle arrest and apoptosis, suggesting the activation of a tetraploidy checkpoint during early development. Finally, we found that p53 downregulation rescued tetraploid embryos later in gestation.
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Horii T, Hatada I. Genome engineering using the CRISPR/Cas system. World J Med Genet 2014; 4:69-76. [DOI: 10.5496/wjmg.v4.i3.69] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/28/2013] [Revised: 03/12/2014] [Accepted: 05/19/2014] [Indexed: 02/06/2023] Open
Abstract
Recently, an epoch-making genome engineering technology using clustered regularly at interspaced short palindromic repeats (CRISPR) and CRISPR associated (Cas) nucleases, was developed. Previous technologies for genome manipulation require the time-consuming design and construction of genome-engineered nucleases for each target and have, therefore, not been widely used in mouse research where standard techniques based on homologous recombination are commonly used. The CRISPR/Cas system only requires the design of sequences complementary to a target locus, making this technology fast and straightforward. In addition, CRISPR/Cas can be used to generate mice carrying mutations in multiple genes in a single step, an achievement not possible using other methods. Here, we review the uses of this technology in genetic analysis and manipulation, including achievements made possible to date and the prospects for future therapeutic applications.
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Yamada H, Tabe Y, Watanabe K, Morishita S, Yuri M, Yokoo M, Horii T, Shimizu N, Kimura S, Ohsaka A. Harmonization of quantitative BCR-ABL measurements using the secondary reference material anchored to the WHO primary standards. Int J Lab Hematol 2014; 37:e29-33. [PMID: 25041536 DOI: 10.1111/ijlh.12274] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Horii T, Arai Y, Yamazaki M, Morita S, Kimura M, Itoh M, Abe Y, Hatada I. Validation of microinjection methods for generating knockout mice by CRISPR/Cas-mediated genome engineering. Sci Rep 2014; 4:4513. [PMID: 24675426 PMCID: PMC5380110 DOI: 10.1038/srep04513] [Citation(s) in RCA: 117] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2013] [Accepted: 03/13/2014] [Indexed: 02/07/2023] Open
Abstract
The CRISPR/Cas system, in which the Cas9 endonuclease and a guide RNA complementary to the target are sufficient for RNA-guided cleavage of the target DNA, is a powerful new approach recently developed for targeted gene disruption in various animal models. However, there is little verification of microinjection methods for generating knockout mice using this approach. Here, we report the verification of microinjection methods of the CRISPR/Cas system. We compared three methods for injection: (1) injection of DNA into the pronucleus, (2) injection of RNA into the pronucleus, and (3) injection of RNA into the cytoplasm. We found that injection of RNA into the cytoplasm was the most efficient method in terms of the numbers of viable blastocyst stage embryos and full-term pups generated. This method also showed the best overall knockout efficiency.
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Morita S, Horii T, Kimura M, Arai Y, Kamei Y, Ogawa Y, Hatada I. Paternal allele influences high fat diet-induced obesity. PLoS One 2014; 9:e85477. [PMID: 24416415 PMCID: PMC3885714 DOI: 10.1371/journal.pone.0085477] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2013] [Accepted: 11/27/2013] [Indexed: 11/18/2022] Open
Abstract
C57BL/6J (B6) mice are susceptible to high-fat diet (HFD)-induced obesity and have been used in metabolism research for many decades. However, the genetic component of HFD-induced obesity has not yet been elucidated. This study reports evidence for a paternal transmission of HFD-induced obesity and a correlated expression of Igf2 and Peg3 (paternal expressed gene 3) imprinted genes. We found that PWK mice are resistant to HFD-induced obesity compared to C57BL/6J mice. Therefore, we generated and analyzed reciprocal crosses between these mice, namely; (PWK×B6) F1 progeny with B6 father and (B6×PWK) F1 progeny with PWK father. The (PWK×B6) F1 mice were more sensitive to diet-induced obesity compared to (B6×PWK) F1 mice, suggesting a paternal transmission of diet-induced obesity. Expression analysis of imprinted genes in adipocytes revealed that HFD influences the expression of some of the imprinted genes in adipose tissue in B6 and PWK mice. Interestingly, Igf2 and Peg3, which are paternally expressed imprinted genes involved in the regulation of body fat accumulation, were down-regulated in B6 and (PWK×B6) F1 mice, which are susceptible to HFD-induced obesity, but not in PWK and (B6×PWK) F1 mice, which are resistant. Furthermore, in vitro analysis showed that Igf2, but not Peg3, had an anti-inflammatory effect on TNF-α induced MCP-1 expression in adipocytes. Taken together, our findings suggest that the down-regulation of Igf2 and Peg3 imprinted genes in adipocytes may be involved in the paternal transmission of HFD-induced obesity.
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Horii T, Morita S, Kimura M, Kobayashi R, Tamura D, Takahashi RU, Kimura H, Suetake I, Ohata H, Okamoto K, Tajima S, Ochiya T, Abe Y, Hatada I. Genome engineering of mammalian haploid embryonic stem cells using the Cas9/RNA system. PeerJ 2013; 1:e230. [PMID: 24432195 PMCID: PMC3883491 DOI: 10.7717/peerj.230] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2013] [Accepted: 12/02/2013] [Indexed: 12/21/2022] Open
Abstract
Haploid embryonic stem cells (ESCs) are useful for studying mammalian genes because disruption of only one allele can cause loss-of-function phenotypes. Here, we report the use of haploid ESCs and the CRISPR RNA-guided Cas9 nuclease gene-targeting system to manipulate mammalian genes. Co-transfection of haploid ESCs with vectors expressing Cas9 nuclease and single-guide RNAs (sgRNAs) targeting Tet1, Tet2, and Tet3 resulted in the complete disruption of all three genes and caused a loss-of-function phenotype with high efficiency (50%). Co-transfection of cells with vectors expressing Cas9 and sgRNAs targeting two loci on the same chromosome resulted in the creation of a large chromosomal deletion and a large inversion. Thus, the use of the CRISPR system in combination with haploid ESCs provides a powerful platform to manipulate the mammalian genome.
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Horii T, Tamura D, Morita S, Kimura M, Hatada I. Generation of an ICF syndrome model by efficient genome editing of human induced pluripotent stem cells using the CRISPR system. Int J Mol Sci 2013; 14:19774-81. [PMID: 24084724 PMCID: PMC3821585 DOI: 10.3390/ijms141019774] [Citation(s) in RCA: 82] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2013] [Revised: 09/11/2013] [Accepted: 09/17/2013] [Indexed: 12/22/2022] Open
Abstract
Genome manipulation of human induced pluripotent stem (iPS) cells is essential to achieve their full potential as tools for regenerative medicine. To date, however, gene targeting in human pluripotent stem cells (hPSCs) has proven to be extremely difficult. Recently, an efficient genome manipulation technology using the RNA-guided DNase Cas9, the clustered regularly interspaced short palindromic repeats (CRISPR) system, has been developed. Here we report the efficient generation of an iPS cell model for immunodeficiency, centromeric region instability, facial anomalies syndrome (ICF) syndrome using the CRISPR system. We obtained iPS cells with mutations in both alleles of DNA methyltransferase 3B (DNMT3B) in 63% of transfected clones. Our data suggest that the CRISPR system is highly efficient and useful for genome engineering of human iPS cells.
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Morita S, Horii T, Kimura M, Hatada I. MiR-184 regulates insulin secretion through repression of Slc25a22. PeerJ 2013; 1:e162. [PMID: 24109547 PMCID: PMC3792180 DOI: 10.7717/peerj.162] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2013] [Accepted: 08/27/2013] [Indexed: 11/20/2022] Open
Abstract
Insulin secretion from pancreatic β-cells plays an essential role in blood glucose homeostasis and type 2 diabetes. Many genes are involved in the secretion of insulin and most of these genes can be targeted by microRNAs (miRNAs). However, the role of miRNAs in insulin secretion and type 2 diabetes has not been exhaustively studied. The expression miR-184, a miRNA enriched in pancreatic islets, negatively correlates with insulin secretion, suggesting that it is a good candidate for miRNA-mediated regulation of insulin secretion. Here we report that miR-184 inhibits insulin secretion in the MIN6 pancreatic β-cell line through the repression of its target Slc25a22, a mitochondrial glutamate carrier. Our study provides new insight into the regulation of insulin secretion by glutamate transport in mitochondria.
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Morita S, Horii T, Kimura M, Ochiya T, Tajima S, Hatada I. miR-29 represses the activities of DNA methyltransferases and DNA demethylases. Int J Mol Sci 2013; 14:14647-58. [PMID: 23857059 PMCID: PMC3742264 DOI: 10.3390/ijms140714647] [Citation(s) in RCA: 106] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2013] [Revised: 06/25/2013] [Accepted: 06/25/2013] [Indexed: 01/21/2023] Open
Abstract
Members of the microRNA-29 (miR-29) family directly target the DNA methyltransferases, DNMT3A and DNMT3B. Disturbances in the expression levels of miR-29 have been linked to tumorigenesis and tumor aggressiveness. Members of the miR-29 family are currently thought to repress DNA methylation and suppress tumorigenesis by protecting against de novo methylation. Here, we report that members of the miR-29 family repress the activities of DNA methyltransferases and DNA demethylases, which have opposing roles in control of DNA methylation status. Members of the miR-29 family directly inhibited DNA methyltransferases and two major factors involved in DNA demethylation, namely tet methylcytosine dioxygenase 1 (TET1) and thymine DNA glycosylase (TDG). Overexpression of miR-29 upregulated the global DNA methylation level in some cancer cells and downregulated DNA methylation in other cancer cells, suggesting that miR-29 suppresses tumorigenesis by protecting against changes in the existing DNA methylation status rather than by preventing de novo methylation of DNA.
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Nakamura A, Miyake K, Misawa S, Kuno Y, Horii T, Kondo S, Tabe Y, Ohsaka A. Meropenem as predictive risk factor for isolation of multidrug-resistant Pseudomonas aeruginosa. J Hosp Infect 2013. [DOI: 10.1016/j.jhin.2012.10.005] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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46
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Morita S, Takahashi RU, Yamashita R, Toyoda A, Horii T, Kimura M, Fujiyama A, Nakai K, Tajima S, Matoba R, Ochiya T, Hatada I. Genome-wide analysis of DNA methylation and expression of microRNAs in breast cancer cells. Int J Mol Sci 2012; 13:8259-8272. [PMID: 22942701 PMCID: PMC3430232 DOI: 10.3390/ijms13078259] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2012] [Revised: 06/19/2012] [Accepted: 06/27/2012] [Indexed: 11/16/2022] Open
Abstract
DNA methylation of promoters is linked to transcriptional silencing of protein-coding genes, and its alteration plays important roles in cancer formation. For example, hypermethylation of tumor suppressor genes has been seen in some cancers. Alteration of methylation in the promoters of microRNAs (miRNAs) has also been linked to transcriptional changes in cancers; however, no systematic studies of methylation and transcription of miRNAs have been reported. In the present study, to clarify the relation between DNA methylation and transcription of miRNAs, next-generation sequencing and microarrays were used to analyze the methylation and expression of miRNAs, protein-coding genes, other non-coding RNAs (ncRNAs), and pseudogenes in the human breast cancer cell lines MCF7 and the adriamycin (ADR) resistant cell line MCF7/ADR. DNA methylation in the proximal promoter of miRNAs is tightly linked to transcriptional silencing, as it is with protein-coding genes. In protein-coding genes, highly expressed genes have CpG-rich proximal promoters whereas weakly expressed genes do not. This is only rarely observed in other gene categories, including miRNAs. The present study highlights the epigenetic similarities and differences between miRNA and protein-coding genes.
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Arisue N, Hashimoto T, Mitsui H, Palacpac NMQ, Kaneko A, Kawai S, Hasegawa M, Tanabe K, Horii T. The Plasmodium Apicoplast Genome: Conserved Structure and Close Relationship of P. ovale to Rodent Malaria Parasites. Mol Biol Evol 2012; 29:2095-9. [DOI: 10.1093/molbev/mss082] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
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48
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Horii T, Yoshida Y, Komatsu K. Surveying awareness of hand hygiene guidelines in the Sanin region of Japan. BMC Proc 2011. [PMCID: PMC3239528 DOI: 10.1186/1753-6561-5-s6-p115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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49
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Horii T, Suetake I, Yanagisawa E, Morita S, Kimura M, Nagao Y, Imai H, Tajima S, Hatada I. The Dnmt3b splice variant is specifically expressed in in vitro-manipulated blastocysts and their derivative ES cells. J Reprod Dev 2011; 57:579-85. [PMID: 21666347 DOI: 10.1262/jrd.10-194a] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Manipulation of preimplantation embryos in vitro, such as in vitro fertilization (IVF), in vitro culture (IVC), intracytoplasmic sperm injection (ICSI), somatic cell nuclear transfer (SCNT) and other assisted reproduction technologies (ART), has contributed to the development of infertility treatment and new animal reproduction methods. However, such embryos often exhibit abnormal DNA methylation patterns in imprinted genes and centromeric satellite repeats. These DNA methylation patterns are established and maintained by three DNA methyltransferases: Dnmt1, Dnmt3a and Dnmt3b. Dnmt3b is responsible for the creation of methylation patterns during the early stage of embryogenesis and consists of many alternative splice variants that affect methylation activity; nevertheless, the roles of these variants have not yet been identified. In this study, we found an alternatively spliced variant of Dnmt3b lacking exon 6 (Dnmt3bΔ6) that is specific to mouse IVC embryos. Dnmt3bΔ6 also showed prominent expression in embryonic stem (ES) cells derived from in vitro manipulated embryos. Interestingly, IVC blastocysts were hypomethylated in centromeric satellite repeat regions that could be susceptible to methylation by Dnmt3b. In vitro methylation activity assays showed that Dnmt3bΔ6 had lower activity than normal Dnmt3b. Our findings suggest that Dnmt3bΔ6 could induce a hypomethylation status especially in in vitro manipulated embryos.
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Takashima Y, Mizohata E, Tokuoka K, Kusakari Y, Krungkrai SR, Matsumura H, Krungkrai J, Horii T, Inoue T. Structure analysis of inhibitor complex of OMP decarboxylase from P. falciparum. Acta Crystallogr A 2011. [DOI: 10.1107/s0108767311092555] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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