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Hao JD, Liu QL, Liu MX, Yang X, Wang LM, Su SY, Xiao W, Zhang MQ, Zhang YC, Zhang L, Chen YS, Yang YG, Ren J. DDX21 mediates co-transcriptional RNA m 6A modification to promote transcription termination and genome stability. Mol Cell 2024; 84:1711-1726.e11. [PMID: 38569554 DOI: 10.1016/j.molcel.2024.03.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 02/09/2024] [Accepted: 03/11/2024] [Indexed: 04/05/2024]
Abstract
N6-methyladenosine (m6A) is a crucial RNA modification that regulates diverse biological processes in human cells, but its co-transcriptional deposition and functions remain poorly understood. Here, we identified the RNA helicase DDX21 with a previously unrecognized role in directing m6A modification on nascent RNA for co-transcriptional regulation. DDX21 interacts with METTL3 for co-recruitment to chromatin through its recognition of R-loops, which can be formed co-transcriptionally as nascent transcripts hybridize onto the template DNA strand. Moreover, DDX21's helicase activity is needed for METTL3-mediated m6A deposition onto nascent RNA following recruitment. At transcription termination regions, this nexus of actions promotes XRN2-mediated termination of RNAPII transcription. Disruption of any of these steps, including the loss of DDX21, METTL3, or their enzymatic activities, leads to defective termination that can induce DNA damage. Therefore, we propose that the R-loop-DDX21-METTL3 nexus forges the missing link for co-transcriptional modification of m6A, coordinating transcription termination and genome stability.
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Affiliation(s)
- Jin-Dong Hao
- Key Laboratory of RNA Science and Engineering, CAS Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences and China National Center for Bioinformation, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Qian-Lan Liu
- Key Laboratory of RNA Science and Engineering, CAS Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences and China National Center for Bioinformation, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Meng-Xia Liu
- Key Laboratory of RNA Science and Engineering, CAS Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences and China National Center for Bioinformation, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China; Sino-Danish College, University of Chinese Academy of Sciences, Beijing 101408, China
| | - Xing Yang
- Key Laboratory of RNA Science and Engineering, CAS Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences and China National Center for Bioinformation, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Liu-Ming Wang
- Key Laboratory of RNA Science and Engineering, CAS Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences and China National Center for Bioinformation, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Si-Yi Su
- Key Laboratory of RNA Science and Engineering, CAS Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences and China National Center for Bioinformation, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China; School of Future Technology, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Wen Xiao
- Key Laboratory of RNA Science and Engineering, CAS Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences and China National Center for Bioinformation, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Meng-Qi Zhang
- Key Laboratory of RNA Science and Engineering, CAS Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences and China National Center for Bioinformation, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yi-Chang Zhang
- Key Laboratory of RNA Science and Engineering, CAS Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences and China National Center for Bioinformation, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Lan Zhang
- Key Laboratory of RNA Science and Engineering, CAS Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences and China National Center for Bioinformation, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China; Sino-Danish College, University of Chinese Academy of Sciences, Beijing 101408, China
| | - Yu-Sheng Chen
- Key Laboratory of RNA Science and Engineering, CAS Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences and China National Center for Bioinformation, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China; Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing 100101, China
| | - Yun-Gui Yang
- Key Laboratory of RNA Science and Engineering, CAS Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences and China National Center for Bioinformation, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China; Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing 100101, China.
| | - Jie Ren
- Key Laboratory of RNA Science and Engineering, CAS Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences and China National Center for Bioinformation, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China; Sino-Danish College, University of Chinese Academy of Sciences, Beijing 101408, China; School of Future Technology, University of Chinese Academy of Sciences, Beijing 100049, China; Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing 100101, China.
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2
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Yague-Sanz C. Shaping the chromatin landscape at rRNA and tRNA genes, an emerging new role for RNA polymerase II transcription? Yeast 2024; 41:135-147. [PMID: 38126234 DOI: 10.1002/yea.3921] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Revised: 11/17/2023] [Accepted: 12/08/2023] [Indexed: 12/23/2023] Open
Abstract
Eukaryotic genes must be condensed into chromatin while remaining accessible to the transcriptional machinery to support gene expression. Among the three eukaryotic RNA polymerases (RNAP), RNAPII is unique, partly because of the C-terminal domain (CTD) of its largest subunit, Rpb1. Rpb1 CTD can be extensively modified during the transcription cycle, allowing for the co-transcriptional recruitment of specific interacting proteins. These include chromatin remodeling factors that control the opening or closing of chromatin. How the CTD-less RNAPI and RNAPIII deal with chromatin at rRNA and tRNA genes is less understood. Here, we review recent advances in our understanding of how the chromatin at tRNA genes and rRNA genes can be remodeled in response to environmental cues in yeast, with a particular focus on the role of local RNAPII transcription in recruiting chromatin remodelers at these loci. In fission yeast, RNAPII transcription at tRNA genes is important to re-establish a chromatin environment permissive to tRNA transcription, which supports growth from stationary phase. In contrast, local RNAPII transcription at rRNA genes correlates with the closing of the chromatin in starvation in budding and fission yeast, suggesting a role in establishing silent chromatin. These opposite roles might support a general model where RNAPII transcription recruits chromatin remodelers to tRNA and rRNA genes to promote the closing and reopening of chromatin in response to the environment.
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Affiliation(s)
- Carlo Yague-Sanz
- Damien Hermand's Laboratory, URPhyM-GEMO, The University of Namur, Namur, Belgium
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3
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Shatskikh AS, Fefelova EA, Klenov MS. Functions of RNAi Pathways in Ribosomal RNA Regulation. Noncoding RNA 2024; 10:19. [PMID: 38668377 PMCID: PMC11054153 DOI: 10.3390/ncrna10020019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2024] [Revised: 03/19/2024] [Accepted: 03/27/2024] [Indexed: 04/29/2024] Open
Abstract
Argonaute proteins, guided by small RNAs, play crucial roles in gene regulation and genome protection through RNA interference (RNAi)-related mechanisms. Ribosomal RNAs (rRNAs), encoded by repeated rDNA units, constitute the core of the ribosome being the most abundant cellular transcripts. rDNA clusters also serve as sources of small RNAs, which are loaded into Argonaute proteins and are able to regulate rDNA itself or affect other gene targets. In this review, we consider the impact of small RNA pathways, specifically siRNAs and piRNAs, on rRNA gene regulation. Data from diverse eukaryotic organisms suggest the potential involvement of small RNAs in various molecular processes related to the rDNA transcription and rRNA fate. Endogenous siRNAs are integral to the chromatin-based silencing of rDNA loci in plants and have been shown to repress rDNA transcription in animals. Small RNAs also play a role in maintaining the integrity of rDNA clusters and may function in the cellular response to rDNA damage. Studies on the impact of RNAi and small RNAs on rRNA provide vast opportunities for future exploration.
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Affiliation(s)
- Aleksei S. Shatskikh
- Koltzov Institute of Developmental Biology, Russian Academy of Sciences, 26 Vavilov Street, 119334 Moscow, Russia;
| | - Elena A. Fefelova
- Institute of Molecular Genetics, Russian Academy of Sciences, 2 Kurchatov Sq., 123182 Moscow, Russia
| | - Mikhail S. Klenov
- Institute of Molecular Genetics, Russian Academy of Sciences, 2 Kurchatov Sq., 123182 Moscow, Russia
- RNA Therapeutics Institute, University of Massachusetts Chan Medical School, 368 Plantation Street, Worcester, MA 01605, USA
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4
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Grypioti E, Richard H, Kryovrysanaki N, Jaubert M, Falciatore A, Verret F, Kalantidis K. Dicer-dependent heterochromatic small RNAs in the model diatom species Phaeodactylum tricornutum. THE NEW PHYTOLOGIST 2024; 241:811-826. [PMID: 38044751 DOI: 10.1111/nph.19429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Accepted: 10/17/2023] [Indexed: 12/05/2023]
Abstract
Diatoms are eukaryotic microalgae responsible for nearly half of the marine productivity. RNA interference (RNAi) is a mechanism of regulation of gene expression mediated by small RNAs (sRNAs) processed by the endoribonuclease Dicer (DCR). To date, the mechanism and physiological role of RNAi in diatoms are unknown. We mined diatom genomes and transcriptomes for key RNAi effectors and retraced their phylogenetic history. We generated DCR knockout lines in the model diatom species Phaeodactylum tricornutum and analyzed their mRNA and sRNA populations, repression-associated histone marks, and acclimatory response to nitrogen starvation. Diatoms presented a diversification of key RNAi effectors whose distribution across species suggests the presence of distinct RNAi pathways. P. tricornutum DCR was found to process 26-31-nt-long double-stranded sRNAs originating mostly from transposons covered by repression-associated epigenetic marks. In parallel, P. tricornutum DCR was necessary for the maintenance of the repression-associated histone marks H3K9me2/3 and H3K27me3. Finally, PtDCR-KO lines presented a compromised recovery post nitrogen starvation suggesting a role for P. tricornutum DCR in the acclimation to nutrient stress. Our study characterized the molecular function of the single DCR homolog of P. tricornutum suggesting an association between RNAi and heterochromatin maintenance in this model diatom species.
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Affiliation(s)
- Emilia Grypioti
- Department of Biology, University of Crete, PO Box 2208, 70013, Heraklion, Crete, Greece
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, 70013, Heraklion, Crete, Greece
- Institute of Marine Biology and Aquaculture, Hellenic Center for Marine Research, 71500, Gournes, Crete, Greece
- Institut de Biologie Paris-Seine, Laboratory of Computational and Quantitative Biology, UMR 7238 Sorbonne Université, 75005, Paris, France
| | - Hugues Richard
- Institut de Biologie Paris-Seine, Laboratory of Computational and Quantitative Biology, UMR 7238 Sorbonne Université, 75005, Paris, France
- Bioinformatics Unit, Genome Competence Center (MF1), Robert Koch Institute, 13353, Berlin, Germany
| | - Nikoleta Kryovrysanaki
- Department of Biology, University of Crete, PO Box 2208, 70013, Heraklion, Crete, Greece
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, 70013, Heraklion, Crete, Greece
| | - Marianne Jaubert
- Institut de Biologie Paris-Seine, Laboratory of Computational and Quantitative Biology, UMR 7238 Sorbonne Université, 75005, Paris, France
- Institut de Biologie Physico-Chimique, Laboratory of Chloroplast Biology and Light Sensing in Microalgae, UMR7141 Centre National de la Recherche Scientifique (CNRS), Sorbonne Université, 75005, Paris, France
| | - Angela Falciatore
- Institut de Biologie Paris-Seine, Laboratory of Computational and Quantitative Biology, UMR 7238 Sorbonne Université, 75005, Paris, France
- Institut de Biologie Physico-Chimique, Laboratory of Chloroplast Biology and Light Sensing in Microalgae, UMR7141 Centre National de la Recherche Scientifique (CNRS), Sorbonne Université, 75005, Paris, France
| | - Frédéric Verret
- Department of Biology, University of Crete, PO Box 2208, 70013, Heraklion, Crete, Greece
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, 70013, Heraklion, Crete, Greece
- Institute of Marine Biology and Aquaculture, Hellenic Center for Marine Research, 71500, Gournes, Crete, Greece
| | - Kriton Kalantidis
- Department of Biology, University of Crete, PO Box 2208, 70013, Heraklion, Crete, Greece
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, 70013, Heraklion, Crete, Greece
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5
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Camino LP, Dutta A, Barroso S, Pérez-Calero C, Katz JN, García-Rubio M, Sung P, Gómez-González B, Aguilera A. DICER ribonuclease removes harmful R-loops. Mol Cell 2023; 83:3707-3719.e5. [PMID: 37827159 PMCID: PMC11034902 DOI: 10.1016/j.molcel.2023.09.021] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 07/08/2023] [Accepted: 09/19/2023] [Indexed: 10/14/2023]
Abstract
R-loops, which consist of a DNA-RNA hybrid and a displaced DNA strand, are known to threaten genome integrity. To counteract this, different mechanisms suppress R-loop accumulation by either preventing the hybridization of RNA with the DNA template (RNA biogenesis factors), unwinding the hybrid (DNA-RNA helicases), or degrading the RNA moiety of the R-loop (type H ribonucleases [RNases H]). Thus far, RNases H are the only nucleases known to cleave DNA-RNA hybrids. Now, we show that the RNase DICER also resolves R-loops. Biochemical analysis reveals that DICER acts by specifically cleaving the RNA within R-loops. Importantly, a DICER RNase mutant impaired in R-loop processing causes a strong accumulation of R-loops in cells. Our results thus not only reveal a function of DICER as an R-loop resolvase independent of DROSHA but also provide evidence for the role of multi-functional RNA processing factors in the maintenance of genome integrity in higher eukaryotes.
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Affiliation(s)
- Lola P Camino
- Centro Andaluz de Biología Molecular y Medicina Regenerativa-CABIMER, Universidad de Sevilla, CSIC, 41092 Seville, Spain; Departamento de Genética, Facultad de Biología, Universidad de Sevilla, 41012 Seville, Spain
| | - Arijit Dutta
- Greehey Children's Cancer Research Institute, Department of Biochemistry and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
| | - Sonia Barroso
- Centro Andaluz de Biología Molecular y Medicina Regenerativa-CABIMER, Universidad de Sevilla, CSIC, 41092 Seville, Spain; Departamento de Genética, Facultad de Biología, Universidad de Sevilla, 41012 Seville, Spain
| | - Carmen Pérez-Calero
- Centro Andaluz de Biología Molecular y Medicina Regenerativa-CABIMER, Universidad de Sevilla, CSIC, 41092 Seville, Spain; Departamento de Genética, Facultad de Biología, Universidad de Sevilla, 41012 Seville, Spain
| | - Jeffrey N Katz
- Greehey Children's Cancer Research Institute, Department of Biochemistry and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
| | - María García-Rubio
- Centro Andaluz de Biología Molecular y Medicina Regenerativa-CABIMER, Universidad de Sevilla, CSIC, 41092 Seville, Spain; Departamento de Genética, Facultad de Biología, Universidad de Sevilla, 41012 Seville, Spain
| | - Patrick Sung
- Greehey Children's Cancer Research Institute, Department of Biochemistry and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA.
| | - Belén Gómez-González
- Centro Andaluz de Biología Molecular y Medicina Regenerativa-CABIMER, Universidad de Sevilla, CSIC, 41092 Seville, Spain; Departamento de Genética, Facultad de Biología, Universidad de Sevilla, 41012 Seville, Spain.
| | - Andrés Aguilera
- Centro Andaluz de Biología Molecular y Medicina Regenerativa-CABIMER, Universidad de Sevilla, CSIC, 41092 Seville, Spain; Departamento de Genética, Facultad de Biología, Universidad de Sevilla, 41012 Seville, Spain.
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6
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Reyes-Castro RA, Chen SY, Seemann J, Kundu ST, Gibbons DL, Arur S. Phosphorylated nuclear DICER1 promotes open chromatin state and lineage plasticity of AT2 tumor cells in lung adenocarcinomas. SCIENCE ADVANCES 2023; 9:eadf6210. [PMID: 37494452 PMCID: PMC10371025 DOI: 10.1126/sciadv.adf6210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Accepted: 06/22/2023] [Indexed: 07/28/2023]
Abstract
KRAS/ERK pathway phosphorylates DICER1, causing its nuclear translocation, and phosphomimetic Dicer1 contributes to tumorigenesis in mice. Mechanisms through which phospho-DICER1 regulates tumor progression remain undefined. While DICER1 canonically regulates microRNAs (miRNA) and epithelial-to-mesenchymal transition (EMT), we found that phosphorylated nuclear DICER1 (phospho-nuclear DICER1) promotes late-stage tumor progression in mice with oncogenic Kras, independent of miRNAs and EMT. Instead, we observe that the murine AT2 tumor cells exhibit altered chromatin compaction, and cells from disorganized advanced tumors, but not localized tumors, express gastric genes. Collectively, this results in subpopulations of tumor cells transitioning from a restricted alveolar to a broader endodermal lineage state. In human LUADs, we observed expression of phospho-nuclear DICER1 in advanced tumors together with the expression of gastric genes. We define a multimeric chromatin-DICER1 complex composed of the Mediator complex subunit 12, CBX1, MACROH2A.1, and transcriptional regulators supporting the model that phospho-nuclear DICER1 leads to lineage reprogramming of AT2 tumor cells to mediate lung cancer progression.
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Affiliation(s)
- Raisa A. Reyes-Castro
- Department of Genetics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
- School of Medicine, University of Puerto Rico, San Juan, Puerto Rico
- Genetics and Epigenetics Graduate Program, The University of Texas MD Anderson Cancer Center and UTHealth Houston Graduate School of Biomedical Sciences, Houston, TX, USA
| | - Shin-Yu Chen
- Department of Genetics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Jacob Seemann
- Department of Genetics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Samrat T. Kundu
- Department of Thoracic/Head and Neck Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
- Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Don L. Gibbons
- Department of Thoracic/Head and Neck Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
- Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Swathi Arur
- Department of Genetics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
- Genetics and Epigenetics Graduate Program, The University of Texas MD Anderson Cancer Center and UTHealth Houston Graduate School of Biomedical Sciences, Houston, TX, USA
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7
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Aiello U, Challal D, Wentzinger G, Lengronne A, Appanah R, Pasero P, Palancade B, Libri D. Sen1 is a key regulator of transcription-driven conflicts. Mol Cell 2022; 82:2952-2966.e6. [PMID: 35839782 DOI: 10.1016/j.molcel.2022.06.021] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Revised: 05/04/2022] [Accepted: 06/13/2022] [Indexed: 10/17/2022]
Abstract
Cellular homeostasis requires the coordination of several machineries concurrently engaged in the DNA. Wide-spread transcription can interfere with other processes, and transcription-replication conflicts (TRCs) threaten genome stability. The conserved Sen1 helicase not only terminates non-coding transcription but also interacts with the replisome and reportedly resolves genotoxic R-loops. Sen1 prevents genomic instability, but how this relates to its molecular functions remains unclear. We generated high-resolution, genome-wide maps of transcription-dependent conflicts and R-loops using a Sen1 mutant that has lost interaction with the replisome but is termination proficient. We show that, under physiological conditions, Sen1 removes RNA polymerase II at TRCs within genes and the rDNA and at sites of transcription-transcription conflicts, thus qualifying as a "key regulator of conflicts." We demonstrate that genomic stability is affected by Sen1 mutation only when in addition to its role at the replisome, the termination of non-coding transcription or R-loop removal are additionally compromised.
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Affiliation(s)
- Umberto Aiello
- Université Paris Cité, CNRS, Institut Jacques Monod, 75013 Paris, France
| | - Drice Challal
- Université Paris Cité, CNRS, Institut Jacques Monod, 75013 Paris, France
| | | | - Armelle Lengronne
- Institut de Génétique Humaine, CNRS, Université de Montpellier, Montpellier, France
| | - Rowin Appanah
- Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9RQ, UK
| | - Philippe Pasero
- Institut de Génétique Humaine, CNRS, Université de Montpellier, Montpellier, France
| | - Benoit Palancade
- Université Paris Cité, CNRS, Institut Jacques Monod, 75013 Paris, France
| | - Domenico Libri
- Université Paris Cité, CNRS, Institut Jacques Monod, 75013 Paris, France.
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8
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Chen Z, Tyler JK. The Chromatin Landscape Channels DNA Double-Strand Breaks to Distinct Repair Pathways. Front Cell Dev Biol 2022; 10:909696. [PMID: 35757003 PMCID: PMC9213757 DOI: 10.3389/fcell.2022.909696] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 05/17/2022] [Indexed: 12/24/2022] Open
Abstract
DNA double-strand breaks (DSBs), the most deleterious DNA lesions, are primarily repaired by two pathways, namely homologous recombination (HR) and non-homologous end joining (NHEJ), the choice of which is largely dependent on cell cycle phase and the local chromatin landscape. Recent studies have revealed that post-translational modifications on histones play pivotal roles in regulating DSB repair pathways including repair pathway choice. In this review, we present our current understanding of how these DSB repair pathways are employed in various chromatin landscapes to safeguard genomic integrity. We place an emphasis on the impact of different histone post-translational modifications, characteristic of euchromatin or heterochromatin regions, on DSB repair pathway choice. We discuss the potential roles of damage-induced chromatin modifications in the maintenance of genome and epigenome integrity. Finally, we discuss how RNA transcripts from the vicinity of DSBs at actively transcribed regions also regulate DSB repair pathway choice.
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Affiliation(s)
- Zulong Chen
- Department of Pathology and Laboratory Medicine, Weill Cornell Medicine, New York City, NY, United States
| | - Jessica K Tyler
- Department of Pathology and Laboratory Medicine, Weill Cornell Medicine, New York City, NY, United States
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9
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Translin facilitates RNA polymerase II dissociation and suppresses genome instability during RNase H2- and Dicer-deficiency. PLoS Genet 2022; 18:e1010267. [PMID: 35714159 PMCID: PMC9246224 DOI: 10.1371/journal.pgen.1010267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 06/30/2022] [Accepted: 05/19/2022] [Indexed: 11/25/2022] Open
Abstract
The conserved nucleic acid binding protein Translin contributes to numerous facets of mammalian biology and genetic diseases. It was first identified as a binder of cancer-associated chromosomal translocation breakpoint junctions leading to the suggestion that it was involved in genetic recombination. With a paralogous partner protein, Trax, Translin has subsequently been found to form a hetero-octomeric RNase complex that drives some of its functions, including passenger strand removal in RNA interference (RNAi). The Translin-Trax complex also degrades the precursors to tumour suppressing microRNAs in cancers deficient for the RNase III Dicer. This oncogenic activity has resulted in the Translin-Trax complex being explored as a therapeutic target. Additionally, Translin and Trax have been implicated in a wider range of biological functions ranging from sleep regulation to telomere transcript control. Here we reveal a Trax- and RNAi-independent function for Translin in dissociating RNA polymerase II from its genomic template, with loss of Translin function resulting in increased transcription-associated recombination and elevated genome instability. This provides genetic insight into the longstanding question of how Translin might influence chromosomal rearrangements in human genetic diseases and provides important functional understanding of an oncological therapeutic target. Human genetic diseases, including cancers, are frequently driven by substantial changes to chromosomes, including translocations, where one arm of a chromosome is exchanged for another. The human nucleic acid binding protein Translin was first identified by its ability to bind to the chromosomal sites at which some of these translocations occur. This resulted in Translin being implicated in the mechanism that generated the translocation and thus the associated disease state. However, since its discovery there has been little evidence to directly indicate Translin does contribute to this process. It is, however, known to contribute to a number of biological functions including, amongst others, neurological regulation, sleep control, vascular stiffening, cancer immunomodulation and it has been recently identified as a potential therapeutic target in some cancers. Here we demonstrate that Translin has conserved function in genome stability maintenance when other primary pathways are defective, a function independent of a key binding partner protein, Trax. Specifically, we demonstrate that Translin contributes to minimizing the deleterious genome destabilizing effects of retaining gene expression machineries on chromosomes. This offers the first evidence for how Translin might contribute to genetic disease-causing chromosomal changes and offers insight to inform therapeutic design.
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10
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Fletcher CE, Deng L, Orafidiya F, Yuan W, Lorentzen MPGS, Cyran OW, Varela-Carver A, Constantin TA, Leach DA, Dobbs FM, Figueiredo I, Gurel B, Parkes E, Bogdan D, Pereira RR, Zhao SG, Neeb A, Issa F, Hester J, Kudo H, Liu Y, Philippou Y, Bristow R, Knudsen K, Bryant RJ, Feng FY, Reed SH, Mills IG, de Bono J, Bevan CL. A non-coding RNA balancing act: miR-346-induced DNA damage is limited by the long non-coding RNA NORAD in prostate cancer. Mol Cancer 2022; 21:82. [PMID: 35317841 PMCID: PMC8939142 DOI: 10.1186/s12943-022-01540-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Accepted: 02/10/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND miR-346 was identified as an activator of Androgen Receptor (AR) signalling that associates with DNA damage response (DDR)-linked transcripts in prostate cancer (PC). We sought to delineate the impact of miR-346 on DNA damage, and its potential as a therapeutic agent. METHODS RNA-IP, RNA-seq, RNA-ISH, DNA fibre assays, in vivo xenograft studies and bioinformatics approaches were used alongside a novel method for amplification-free, single nucleotide-resolution genome-wide mapping of DNA breaks (INDUCE-seq). RESULTS miR-346 induces rapid and extensive DNA damage in PC cells - the first report of microRNA-induced DNA damage. Mechanistically, this is achieved through transcriptional hyperactivation, R-loop formation and replication stress, leading to checkpoint activation and cell cycle arrest. miR-346 also interacts with genome-protective lncRNA NORAD to disrupt its interaction with PUM2, leading to PUM2 stabilisation and its increased turnover of DNA damage response (DDR) transcripts. Confirming clinical relevance, NORAD expression and activity strongly correlate with poor PC clinical outcomes and increased DDR in biopsy RNA-seq studies. In contrast, miR-346 is associated with improved PC survival. INDUCE-seq reveals that miR-346-induced DSBs occur preferentially at binding sites of the most highly-transcriptionally active transcription factors in PC cells, including c-Myc, FOXA1, HOXB13, NKX3.1, and importantly, AR, resulting in target transcript downregulation. Further, RNA-seq reveals widespread miR-346 and shNORAD dysregulation of DNA damage, replication and cell cycle processes. NORAD drives target-directed miR decay (TDMD) of miR-346 as a novel genome protection mechanism: NORAD silencing increases mature miR-346 levels by several thousand-fold, and WT but not TDMD-mutant NORAD rescues miR-346-induced DNA damage. Importantly, miR-346 sensitises PC cells to DNA-damaging drugs including PARP inhibitor and chemotherapy, and induces tumour regression as a monotherapy in vivo, indicating that targeting miR-346:NORAD balance is a valid therapeutic strategy. CONCLUSIONS A balancing act between miR-346 and NORAD regulates DNA damage and repair in PC. miR-346 may be particularly effective as a therapeutic in the context of decreased NORAD observed in advanced PC, and in transcriptionally-hyperactive cancer cells.
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Affiliation(s)
- C E Fletcher
- Imperial Centre for Translational and Experimental Medicine, Department of Surgery & Cancer, Imperial College London, London, UK.
| | - L Deng
- Imperial Centre for Translational and Experimental Medicine, Department of Surgery & Cancer, Imperial College London, London, UK
| | - F Orafidiya
- Imperial Centre for Translational and Experimental Medicine, Department of Surgery & Cancer, Imperial College London, London, UK
| | - W Yuan
- Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, Sutton, UK
| | - M P G S Lorentzen
- Imperial Centre for Translational and Experimental Medicine, Department of Surgery & Cancer, Imperial College London, London, UK
| | - O W Cyran
- Imperial Centre for Translational and Experimental Medicine, Department of Surgery & Cancer, Imperial College London, London, UK
| | - A Varela-Carver
- Imperial Centre for Translational and Experimental Medicine, Department of Surgery & Cancer, Imperial College London, London, UK
| | - T A Constantin
- Imperial Centre for Translational and Experimental Medicine, Department of Surgery & Cancer, Imperial College London, London, UK
| | - D A Leach
- Imperial Centre for Translational and Experimental Medicine, Department of Surgery & Cancer, Imperial College London, London, UK
| | - F M Dobbs
- Division of Cancer and Genetics, School of Medicine, Cardiff University, Heath Park, Cardiff, UK
- Broken String Biosciences, Unit AB303, Level 3, BioData Innovation Centre, Wellcome Genome Campus, Hinxton, Cambridge, UK
| | - I Figueiredo
- Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, Sutton, UK
| | - B Gurel
- Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, Sutton, UK
| | - E Parkes
- Institute for Radiation Oncology, Department of Oncology, University of Oxford, London, UK
| | - D Bogdan
- Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, Sutton, UK
| | - R R Pereira
- Translational Oncogenomics, Manchester Cancer Research Centre and Cancer Research UK Manchester Institute, Manchester, UK
- Division of Cancer Sciences, Faculty of Biology Medicine and Health, University of Manchester, Manchester, UK
| | - S G Zhao
- Department of Human Oncology, University of Wisconsin School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, USA
| | - A Neeb
- Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, Sutton, UK
| | - F Issa
- Transplantation Research and Immunology Group, Nuffield Department of Surgical Sciences, University of Oxford, Oxford, UK
| | - J Hester
- Transplantation Research and Immunology Group, Nuffield Department of Surgical Sciences, University of Oxford, Oxford, UK
| | - H Kudo
- Section of Pathology, Department of Metabolism, Digestion and Reproduction, Imperial College London, London, UK
| | - Y Liu
- Veracyte, Inc., San Diego, CA, USA
| | - Y Philippou
- Nuffield Department of Surgical Sciences, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | - R Bristow
- Translational Oncogenomics, Manchester Cancer Research Centre and Cancer Research UK Manchester Institute, Manchester, UK
- Division of Cancer Sciences, Faculty of Biology Medicine and Health, University of Manchester, Manchester, UK
- Christie NHS Foundation Trust, Manchester, UK
| | - K Knudsen
- Department of Cancer Biology, Thomas Jefferson University, Philadelphia, PA, USA
- American Cancer Society and American Cancer Society Cancer Action Network, Washington DC, USA
| | - R J Bryant
- Institute for Radiation Oncology, Department of Oncology, University of Oxford, London, UK
| | - F Y Feng
- Departments of Urology and Radiation Oncology, University of California San Francisco, San Francisco, CA, USA
| | - S H Reed
- Division of Cancer and Genetics, School of Medicine, Cardiff University, Heath Park, Cardiff, UK
| | - I G Mills
- Nuffield Department of Surgical Sciences, University of Oxford, John Radcliffe Hospital, Oxford, UK
- Patrick G Johnston Centre for Cancer Research, Queen's University of Belfast, Belfast, UK
- Centre for Cancer Biomarkers, University of Bergen, Bergen, Norway
- Department of Clinical Science, University of Bergen, Bergen, Norway
| | - J de Bono
- Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, Sutton, UK
| | - C L Bevan
- Imperial Centre for Translational and Experimental Medicine, Department of Surgery & Cancer, Imperial College London, London, UK
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11
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Dicer promotes genome stability via the bromodomain transcriptional co-activator BRD4. Nat Commun 2022; 13:1001. [PMID: 35194019 PMCID: PMC8863982 DOI: 10.1038/s41467-022-28554-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Accepted: 01/14/2022] [Indexed: 01/01/2023] Open
Abstract
RNA interference is required for post-transcriptional silencing, but also has additional roles in transcriptional silencing of centromeres and genome stability. However, these roles have been controversial in mammals. Strikingly, we found that Dicer-deficient embryonic stem cells have strong proliferation and chromosome segregation defects as well as increased transcription of centromeric satellite repeats, which triggers the interferon response. We conducted a CRISPR-Cas9 genetic screen to restore viability and identified transcriptional activators, histone H3K9 methyltransferases, and chromosome segregation factors as suppressors, resembling Dicer suppressors identified in independent screens in fission yeast. The strongest suppressors were mutations in the transcriptional co-activator Brd4, which reversed the strand-specific transcription of major satellite repeats suppressing the interferon response, and in the histone acetyltransferase Elp3. We show that identical mutations in the second bromodomain of Brd4 rescue Dicer-dependent silencing and chromosome segregation defects in both mammalian cells and fission yeast. This remarkable conservation demonstrates that RNA interference has an ancient role in transcriptional silencing and in particular of satellite repeats, which is essential for cell cycle progression and proper chromosome segregation. Our results have pharmacological implications for cancer and autoimmune diseases characterized by unregulated transcription of satellite repeats. While RNA interference is conserved across species, small RNA pathways are very diverse. In this study, Gutbrod et al. find that non-canonical roles of Dicer in genome stability are in fact deeply conserved from yeast to humans.
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12
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Wu W, He JN, Lan M, Zhang P, Chu WK. Transcription-Replication Collisions and Chromosome Fragility. Front Genet 2021; 12:804547. [PMID: 34956339 PMCID: PMC8703014 DOI: 10.3389/fgene.2021.804547] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Accepted: 11/29/2021] [Indexed: 11/13/2022] Open
Abstract
Accurate replication of the entire genome is critical for cell division and propagation. Certain regions in the genome, such as fragile sites (common fragile sites, rare fragile sites, early replicating fragile sites), rDNA and telomeres, are intrinsically difficult to replicate, especially in the presence of replication stress caused by, for example, oncogene activation during tumor development. Therefore, these regions are particularly prone to deletions and chromosome rearrangements during tumorigenesis, rendering chromosome fragility. Although, the mechanism underlying their “difficult-to-replicate” nature and genomic instability is still not fully understood, accumulating evidence suggests transcription might be a major source of endogenous replication stress (RS) leading to chromosome fragility. Here, we provide an updated overview of how transcription affects chromosome fragility. Furthermore, we will use the well characterized common fragile sites (CFSs) as a model to discuss pathways involved in offsetting transcription-induced RS at these loci with a focus on the recently discovered atypical DNA synthesis repair pathway Mitotic DNA Synthesis (MiDAS).
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Affiliation(s)
- Wei Wu
- Zhejiang Provincial Key Laboratory of Pancreatic Diseases, The First Affiliated Hospital of Zhejiang University, Hangzhou, China
| | - Jing Na He
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, Hong Kong, China
| | - Mengjiao Lan
- Zhejiang Provincial Key Laboratory of Pancreatic Diseases, The First Affiliated Hospital of Zhejiang University, Hangzhou, China
| | - Pumin Zhang
- Zhejiang Provincial Key Laboratory of Pancreatic Diseases, The First Affiliated Hospital of Zhejiang University, Hangzhou, China
| | - Wai Kit Chu
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, Hong Kong, China
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13
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Wahba L, Hansen L, Fire AZ. An essential role for the piRNA pathway in regulating the ribosomal RNA pool in C. elegans. Dev Cell 2021; 56:2295-2312.e6. [PMID: 34388368 PMCID: PMC8387450 DOI: 10.1016/j.devcel.2021.07.014] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 06/11/2021] [Accepted: 07/15/2021] [Indexed: 01/08/2023]
Abstract
Piwi-interacting RNAs (piRNAs) are RNA effectors with key roles in maintaining genome integrity and promoting fertility in metazoans. In Caenorhabditis elegans loss of piRNAs leads to a transgenerational sterility phenotype. The plethora of piRNAs and their ability to silence transcripts with imperfect complementarity have raised several (non-exclusive) models for the underlying drivers of sterility. Here, we report the extranuclear and transferable nature of the sterility driver, its suppression via mutations disrupting the endogenous RNAi and poly-uridylation machinery, and copy-number amplification at the ribosomal DNA locus. In piRNA-deficient animals, several small interfering RNA (siRNA) populations become increasingly overabundant in the generations preceding loss of germline function, including ribosomal siRNAs (risiRNAs). A concomitant increase in uridylated sense rRNA fragments suggests that poly-uridylation may potentiate RNAi-mediated gene silencing of rRNAs. We conclude that loss of the piRNA machinery allows for unchecked amplification of siRNA populations, originating from abundant highly structured RNAs, to deleterious levels.
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Affiliation(s)
- Lamia Wahba
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Loren Hansen
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Andrew Z Fire
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA.
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14
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Apte MS, Masuda H, Wheeler DL, Cooper JP. RNAi and Ino80 complex control rate limiting translocation step that moves rDNA to eroding telomeres. Nucleic Acids Res 2021; 49:8161-8176. [PMID: 34244792 PMCID: PMC8373062 DOI: 10.1093/nar/gkab586] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 06/18/2021] [Accepted: 07/01/2021] [Indexed: 01/21/2023] Open
Abstract
The discovery of HAATIrDNA, a telomerase-negative survival mode in which canonical telomeres are replaced with ribosomal DNA (rDNA) repeats that acquire chromosome end-protection capability, raised crucial questions as to how rDNA tracts 'jump' to eroding chromosome ends. Here, we show that HAATIrDNA formation is initiated and limited by a single translocation that juxtaposes rDNA from Chromosome (Chr) III onto subtelomeric elements (STE) on Chr I or II; this rare reaction requires RNAi and the Ino80 nucleosome remodeling complex (Ino80C), thus defining an unforeseen relationship between these two machineries. The unique STE-rDNA junction created by this initial translocation is efficiently copied to the remaining STE chromosome ends, independently of RNAi or Ino80C. Intriguingly, both RNAi and Ino80C machineries contain a component that plays dual roles in HAATI subtype choice. Dcr1 of the RNAi pathway and Iec1 of Ino80C both promote HAATIrDNA formation as part of their respective canonical machineries, but both also inhibit formation of the exceedingly rare HAATISTE (where STE sequences mobilize throughout the genome and assume chromosome end protection capacity) in non-canonical, pathway-independent manners. This work provides a glimpse into a previously unrecognized crosstalk between RNAi and Ino80C in controlling unusual translocation reactions that establish telomere-free linear chromosome ends.
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Affiliation(s)
- Manasi S Apte
- Laboratory of Biochemistry and Molecular Biology, NCI, NIH, Bethesda, MD 20892, USA
| | - Hirohisa Masuda
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - David Lee Wheeler
- Laboratory of Biochemistry and Molecular Biology, NCI, NIH, Bethesda, MD 20892, USA
| | - Julia Promisel Cooper
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
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15
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Lalonde M, Trauner M, Werner M, Hamperl S. Consequences and Resolution of Transcription-Replication Conflicts. Life (Basel) 2021; 11:life11070637. [PMID: 34209204 PMCID: PMC8303131 DOI: 10.3390/life11070637] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2021] [Revised: 06/28/2021] [Accepted: 06/28/2021] [Indexed: 11/17/2022] Open
Abstract
Transcription–replication conflicts occur when the two critical cellular machineries responsible for gene expression and genome duplication collide with each other on the same genomic location. Although both prokaryotic and eukaryotic cells have evolved multiple mechanisms to coordinate these processes on individual chromosomes, it is now clear that conflicts can arise due to aberrant transcription regulation and premature proliferation, leading to DNA replication stress and genomic instability. As both are considered hallmarks of aging and human diseases such as cancer, understanding the cellular consequences of conflicts is of paramount importance. In this article, we summarize our current knowledge on where and when collisions occur and how these encounters affect the genome and chromatin landscape of cells. Finally, we conclude with the different cellular pathways and multiple mechanisms that cells have put in place at conflict sites to ensure the resolution of conflicts and accurate genome duplication.
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16
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Feng W, Yang M, Li X, Wei D. Dicer promotes Atg8 expression through RNAi independent mechanism in Cryptococcus neoformans. FEMS Yeast Res 2021; 21:6311133. [PMID: 34185085 DOI: 10.1093/femsyr/foab037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 06/26/2021] [Indexed: 11/12/2022] Open
Abstract
ATG8 is one of the critical genes that participate in several essential autophagic steps. The expression of ATG8 must be exquisitely regulated to avoid physiological disorder and even cell death. However, the mechanisms of regulating ATG8 expression remain to be fully uncovered. In this investigation, we found that Dicer homologs in Cryptococcus neoformans could activate the expression of ATG8 independent of RNAi. Deletion of two Dicer homologs (DCR1 and DCR2) from C. neoformans, especially DCR2, led to significantly reduced Atg8 protein level, but deletion of other RNAi components did not result in the same phenotype. The autophagic flux, the numbers of autophagic bodies and the tolerance to glucose starvation of dcr2∆ were also significantly reduced. Further investigation showed that Dcr2 activates the expression of ATG8 through the promoter region, not the Open Reading Frame or 3' Untranslated Region. We also found that a similar phenomenon exists in mammalian cells, as DCR1 instead of AGO2 knockdown also reduced the expression of LC3, indicating that this mechanism may be conservative in eukaryotic cells. Therefore, a novel transcription activation mechanism was revealed in this paper.
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Affiliation(s)
- Weijia Feng
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, College of Life Science, Nankai University, Tianjin 300071, China
| | - Mengdi Yang
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, College of Life Science, Nankai University, Tianjin 300071, China
| | - Xin Li
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, College of Life Science, Nankai University, Tianjin 300071, China
| | - Dongsheng Wei
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, College of Life Science, Nankai University, Tianjin 300071, China
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17
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Lee SR, Pollard DA, Galati DF, Kelly ML, Miller B, Mong C, Morris MN, Roberts-Nygren K, Kapler GM, Zinkgraf M, Dang HQ, Branham E, Sasser J, Tessier E, Yoshiyama C, Matsumoto M, Turman G. Disruption of a ∼23-24 nucleotide small RNA pathway elevates DNA damage responses in Tetrahymena thermophila. Mol Biol Cell 2021; 32:1335-1346. [PMID: 34010017 PMCID: PMC8694037 DOI: 10.1091/mbc.e20-10-0631] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Endogenous RNA interference (RNAi) pathways regulate a wide range of cellular processes in diverse eukaryotes, yet in the ciliated eukaryote, Tetrahymena thermophila, the cellular purpose of RNAi pathways that generate ∼23–24 nucleotide (nt) small (s)RNAs has remained unknown. Here, we investigated the phenotypic and gene expression impacts on vegetatively growing cells when genes involved in ∼23–24 nt sRNA biogenesis are disrupted. We observed slower proliferation and increased expression of genes involved in DNA metabolism and chromosome organization and maintenance in sRNA biogenesis mutants RSP1Δ, RDN2Δ, and RDF2Δ. In addition, RSP1Δ and RDN2Δ cells frequently exhibited enlarged chromatin extrusion bodies, which are nonnuclear, DNA-containing structures that may be akin to mammalian micronuclei. Expression of homologous recombination factor Rad51 was specifically elevated in RSP1Δ and RDN2Δ strains, with Rad51 and double-stranded DNA break marker γ-H2A.X localized to discrete macronuclear foci. In addition, an increase in Rad51 and γ-H2A.X foci was also found in knockouts of TWI8, a macronucleus-localized PIWI protein. Together, our findings suggest that an evolutionarily conserved role for RNAi pathways in maintaining genome integrity may be extended even to the early branching eukaryotic lineage that gave rise to Tetrahymena thermophila.
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Affiliation(s)
- Suzanne R Lee
- Biology Department, Western Washington University, Bellingham, WA 98225
| | - Daniel A Pollard
- Biology Department, Western Washington University, Bellingham, WA 98225
| | - Domenico F Galati
- Biology Department, Western Washington University, Bellingham, WA 98225
| | - Megan L Kelly
- Biology Department, Western Washington University, Bellingham, WA 98225
| | - Brian Miller
- Biology Department, Western Washington University, Bellingham, WA 98225
| | - Christina Mong
- Biology Department, Western Washington University, Bellingham, WA 98225
| | - Megan N Morris
- Biology Department, Western Washington University, Bellingham, WA 98225
| | | | - Geoffrey M Kapler
- Molecular and Cellular Medicine, Texas A&M University, College Station, TX 77843
| | - Matthew Zinkgraf
- Biology Department, Western Washington University, Bellingham, WA 98225
| | - Hung Q Dang
- Molecular and Cellular Medicine, Texas A&M University, College Station, TX 77843
| | - Erica Branham
- Molecular and Cellular Medicine, Texas A&M University, College Station, TX 77843
| | - Jason Sasser
- Biology Department, Western Washington University, Bellingham, WA 98225
| | - Erin Tessier
- Biology Department, Western Washington University, Bellingham, WA 98225
| | | | - Maya Matsumoto
- Biology Department, Western Washington University, Bellingham, WA 98225
| | - Gaea Turman
- Biology Department, Western Washington University, Bellingham, WA 98225
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18
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Dutertre M, Sfaxi R, Vagner S. Reciprocal Links between Pre-messenger RNA 3'-End Processing and Genome Stability. Trends Biochem Sci 2021; 46:579-594. [PMID: 33653631 DOI: 10.1016/j.tibs.2021.01.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 01/11/2021] [Accepted: 01/22/2021] [Indexed: 02/07/2023]
Abstract
The 3'-end processing of most pre-messenger RNAs (pre-mRNAs) involves RNA cleavage and polyadenylation and is coupled to transcription termination. In both yeast and human cells, pre-mRNA 3'-end cleavage is globally inhibited by DNA damage. Recently, further links between pre-mRNA 3'-end processing and the control of genome stability have been uncovered, as reviewed here. Upon DNA damage, various genes related to the DNA damage response (DDR) escape 3'-end processing inhibition or are regulated through alternative polyadenylation (APA). Conversely, various pre-mRNA 3'-end processing factors prevent genome instability and are found at sites of DNA damage. Finally, the reciprocal link between pre-mRNA 3'-end processing and genome stability control seems important because it is conserved in evolution and involved in disease development.
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Affiliation(s)
- Martin Dutertre
- Institut Curie, Université PSL, CNRS UMR3348, INSERM U1278, 91400 Orsay, France; Université Paris-Saclay, CNRS UMR3348, INSERM U1278, 91400 Orsay, France; Equipe Labellisée Ligue Nationale Contre le Cancer.
| | - Rym Sfaxi
- Institut Curie, Université PSL, CNRS UMR3348, INSERM U1278, 91400 Orsay, France; Université Paris-Saclay, CNRS UMR3348, INSERM U1278, 91400 Orsay, France; Equipe Labellisée Ligue Nationale Contre le Cancer
| | - Stéphan Vagner
- Institut Curie, Université PSL, CNRS UMR3348, INSERM U1278, 91400 Orsay, France; Université Paris-Saclay, CNRS UMR3348, INSERM U1278, 91400 Orsay, France; Equipe Labellisée Ligue Nationale Contre le Cancer.
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19
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Sims J, Rabanal FA, Elgert C, von Haeseler A, Schlögelhofer P. It Is Just a Matter of Time: Balancing Homologous Recombination and Non-homologous End Joining at the rDNA Locus During Meiosis. FRONTIERS IN PLANT SCIENCE 2021; 12:773052. [PMID: 34777453 PMCID: PMC8580885 DOI: 10.3389/fpls.2021.773052] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Accepted: 10/04/2021] [Indexed: 05/17/2023]
Abstract
Ribosomal RNA genes (rDNAs) are located in large domains of hundreds of rDNA units organized in a head-to-tail manner. The proper and stable inheritance of rDNA clusters is of paramount importance for survival. Yet, these highly repetitive elements pose a potential risk to the genome since they can undergo non-allelic exchanges. Here, we review the current knowledge of the organization of the rDNA clusters in Arabidopsis thaliana and their stability during meiosis. Recent findings suggest that during meiosis, all rDNA loci are embedded within the nucleolus favoring non-homologous end joining (NHEJ) as a repair mechanism, while DNA repair via homologous recombination (HR) appears to be a rare event. We propose a model where (1) frequent meiotic NHEJ events generate abundant single nucleotide polymorphisms and insertions/deletions within the rDNA, resulting in a heterogeneous population of rDNA units and (2) rare HR events dynamically change rDNA unit numbers, only to be observed in large populations over many generations. Based on the latest efforts to delineate the entire rDNA sequence in A. thaliana, we discuss evidence supporting this model. The results compiled so far draw a surprising picture of rDNA sequence heterogeneity between individual units. Furthermore, rDNA cluster sizes have been recognized as relatively stable when observing less than 10 generations, yet emerged as major determinant of genome size variation between different A. thaliana ecotypes. The sequencing efforts also revealed that transcripts from the diverse rDNA units yield heterogenous ribosome populations with potential functional implications. These findings strongly motivate further research to understand the mechanisms that maintain the metastable state of rDNA loci.
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Affiliation(s)
- Jason Sims
- Department of Chromosome Biology, Max Perutz Labs, University of Vienna, Vienna BioCenter, Vienna, Austria
- *Correspondence: Jason Sims,
| | - Fernando A. Rabanal
- Department of Molecular Biology, Max Planck Institute for Developmental Biology, Tübingen, Germany
| | - Christiane Elgert
- Center for Integrative Bioinformatics Vienna (CIBIV), Max Perutz Labs, University of Vienna and Medical University of Vienna, Vienna BioCenter, Vienna, Austria
| | - Arndt von Haeseler
- Center for Integrative Bioinformatics Vienna (CIBIV), Max Perutz Labs, University of Vienna and Medical University of Vienna, Vienna BioCenter, Vienna, Austria
- Bioinformatics and Computational Biology, Faculty of Computer Science, University of Vienna, Vienna, Austria
| | - Peter Schlögelhofer
- Department of Chromosome Biology, Max Perutz Labs, University of Vienna, Vienna BioCenter, Vienna, Austria
- Peter Schlögelhofer,
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20
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Hu Y, Tareen A, Sheu YJ, Ireland WT, Speck C, Li H, Joshua-Tor L, Kinney JB, Stillman B. Evolution of DNA replication origin specification and gene silencing mechanisms. Nat Commun 2020; 11:5175. [PMID: 33056978 PMCID: PMC7560902 DOI: 10.1038/s41467-020-18964-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Accepted: 09/22/2020] [Indexed: 02/08/2023] Open
Abstract
DNA replication in eukaryotic cells initiates from replication origins that bind the Origin Recognition Complex (ORC). Origin establishment requires well-defined DNA sequence motifs in Saccharomyces cerevisiae and some other budding yeasts, but most eukaryotes lack sequence-specific origins. A 3.9 Å structure of S. cerevisiae ORC-Cdc6-Cdt1-Mcm2-7 (OCCM) bound to origin DNA revealed that a loop within Orc2 inserts into a DNA minor groove and an α-helix within Orc4 inserts into a DNA major groove. Using a massively parallel origin selection assay coupled with a custom mutual-information-based modeling approach, and a separate analysis of whole-genome replication profiling, here we show that the Orc4 α-helix contributes to the DNA sequence-specificity of origins in S. cerevisiae and Orc4 α-helix mutations change genome-wide origin firing patterns. The DNA sequence specificity of replication origins, mediated by the Orc4 α-helix, has co-evolved with the gain of ORC-Sir4-mediated gene silencing and the loss of RNA interference.
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Affiliation(s)
- Y Hu
- Cold Spring Harbor Laboratory, 1 Bungtown Road, Cold Spring Harbor, NY, 11724, USA
- Program in Molecular and Cell Biology, Stony Brook University, Stony Brook, NY, 11794, USA
| | - A Tareen
- Cold Spring Harbor Laboratory, 1 Bungtown Road, Cold Spring Harbor, NY, 11724, USA
- Simons Center for Quantitative Biology, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, 11724, USA
| | - Y-J Sheu
- Cold Spring Harbor Laboratory, 1 Bungtown Road, Cold Spring Harbor, NY, 11724, USA
| | - W T Ireland
- Department of Physics, California Institute of Technology, Pasadena, CA, 91125, USA
| | - C Speck
- DNA Replication Group, Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, W12 0NN, London, UK
| | - H Li
- Structural Biology Program, Van Andel Institute, Grand Rapids, MI, 49503, USA
| | - L Joshua-Tor
- Cold Spring Harbor Laboratory, 1 Bungtown Road, Cold Spring Harbor, NY, 11724, USA
- W. M. Keck Structural Biology Laboratory, Howard Hughes Medical Institute, Cold Spring Harbor, NY, 11724, USA
| | - J B Kinney
- Cold Spring Harbor Laboratory, 1 Bungtown Road, Cold Spring Harbor, NY, 11724, USA
- Simons Center for Quantitative Biology, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, 11724, USA
| | - B Stillman
- Cold Spring Harbor Laboratory, 1 Bungtown Road, Cold Spring Harbor, NY, 11724, USA.
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21
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The critical impacts of small RNA biogenesis proteins on aging, longevity and age-related diseases. Ageing Res Rev 2020; 62:101087. [PMID: 32497728 DOI: 10.1016/j.arr.2020.101087] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Revised: 04/01/2020] [Accepted: 05/11/2020] [Indexed: 12/13/2022]
Abstract
Small RNAs and enzymes that provide their biogenesis and functioning are involved in the organism development and coordination of biological processes, including metabolism, maintaining genome integrity, immune and stress responses. In this review, we focused on the role of small RNA biogenesis proteins in determining the aging and longevity of animals and human. A number of studies have revealed that changes in expression profiles of key enzymes, in particular proteins of the Drosha, Dicer and Argonaute families, are associated with the aging process, as well as with some age-related diseases and progeroid syndromes. Down-regulation of small RNA biogenesis proteins leads to global alterations in the expression of regulatory RNAs, disruption of key molecular, cellular and systemic processes, which leads to a lifespan shortening. In contrast, overexpression of Dicer prolongs lifespan and improves cellular defense. Additionally, the role of small RNA biogenesis proteins in the pathogenesis of age-related diseases, including cancer, inflammaging, neurodegeneration, cardiovascular, metabolic and immune disorders, has been conclusively evidenced. Recent advances in biomedicine allow using these proteins as diagnostic and prognostic biomarkers and therapeutic targets.
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22
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Lambo S, von Hoff K, Korshunov A, Pfister SM, Kool M. ETMR: a tumor entity in its infancy. Acta Neuropathol 2020; 140:249-266. [PMID: 32601913 PMCID: PMC7423804 DOI: 10.1007/s00401-020-02182-2] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 06/04/2020] [Accepted: 06/18/2020] [Indexed: 12/18/2022]
Abstract
Embryonal tumor with Multilayered Rosettes (ETMR) is a relatively rare but typically deadly type of brain tumor that occurs mostly in infants. Since the discovery of the characteristic chromosome 19 miRNA cluster (C19MC) amplification a decade ago, the methods for diagnosing this entity have improved and many new insights in the molecular landscape of ETMRs have been acquired. All ETMRs, despite their highly heterogeneous histology, are characterized by specific high expression of the RNA-binding protein LIN28A, which is, therefore, often used as a diagnostic marker for these tumors. ETMRs have few recurrent genetic aberrations, mainly affecting the miRNA pathway and including amplification of C19MC (embryonal tumor with multilayered rosettes, C19MC-altered) and mutually exclusive biallelic DICER1 mutations of which the first hit is typically inherited through the germline (embryonal tumor with multilayered rosettes, DICER1-altered). Identification of downstream pathways affected by the deregulated miRNA machinery has led to several proposed potential therapeutical vulnerabilities including targeting the WNT, SHH, or mTOR pathways, MYCN or chromosomal instability. However, despite those findings, treatment outcomes have only marginally improved, since the initial description of this tumor entity. Many patients do not survive longer than a year after diagnosis and the 5-year overall survival rate is still lower than 30%. Thus, there is an urgent need to translate the new insights in ETMR biology into more effective treatments. Here, we present an overview of clinical and molecular characteristics of ETMRs and the current progress on potential targeted therapies.
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Affiliation(s)
- Sander Lambo
- Hopp Children's Cancer Center (KiTZ), Heidelberg, Germany
- Division of Pediatric Neurooncology, German Cancer Research Center (DKFZ), German Cancer Consortium (DKTK), Heidelberg, Germany
| | - Katja von Hoff
- Department of Pediatric Oncology/Hematology, Charité University Medicine, Berlin, Germany
| | - Andrey Korshunov
- Department of Neuropathology, Heidelberg University Hospital, Heidelberg, Germany
- Clinical Cooperation Unit Neuropathology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Stefan M Pfister
- Hopp Children's Cancer Center (KiTZ), Heidelberg, Germany
- Division of Pediatric Neurooncology, German Cancer Research Center (DKFZ), German Cancer Consortium (DKTK), Heidelberg, Germany
- Department of Pediatric Oncology, Hematology and Immunology, University Hospital Heidelberg, Heidelberg, Germany
| | - Marcel Kool
- Hopp Children's Cancer Center (KiTZ), Heidelberg, Germany.
- Division of Pediatric Neurooncology, German Cancer Research Center (DKFZ), German Cancer Consortium (DKTK), Heidelberg, Germany.
- Princess Máxima Center for Pediatric Oncology, Utrecht, The Netherlands.
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23
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F de Felippes F, McHale M, Doran RL, Roden S, Eamens AL, Finnegan EJ, Waterhouse PM. The key role of terminators on the expression and post-transcriptional gene silencing of transgenes. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 104:96-112. [PMID: 32603508 DOI: 10.1111/tpj.14907] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 05/08/2020] [Accepted: 06/17/2020] [Indexed: 05/18/2023]
Abstract
Transgenes have become essential to modern biology, being an important tool in functional genomic studies and also in the development of biotechnological products. One of the major challenges in the generation of transgenic lines concerns the expression of transgenes, which, compared to endogenes, are particularly susceptible to silencing mediated by small RNAs (sRNAs). Several reasons have been put forward to explain why transgenes often trigger the production of sRNAs, such as the high level of expression induced by commonly used strong constitutive promoters, the lack of introns, and features resembling viral and other exogenous sequences. However, the relative contributions of the different genomic elements with respect to protecting genes from the silencing machinery and their molecular mechanisms remain unclear. Here, we present the results of a mutagenesis screen conceived to identify features involved in the protection of endogenes against becoming a template for the production of sRNAs. Interestingly, all of the recovered mutants had alterations in genes with proposed function in transcription termination, suggesting a central role of terminators in this process. Indeed, using a GFP reporter system, we show that, among different genetic elements tested, the terminator sequence had the greatest effect on transgene-derived sRNA accumulation and that a well-defined poly(A) site might be especially important. Finally, we describe an unexpected mechanism, where transgenes containing certain intron/terminator combinations lead to an increase in the production of sRNAs, which appears to interfere with splicing.
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Affiliation(s)
- Felipe F de Felippes
- Centre for Agriculture and the Bioeconomy, Institute for Future Environments, Queensland University of Technology (QUT), 2 George Street, Brisbane, QLD, 4000, Australia
| | - Marcus McHale
- Plant Systems Biology Laboratory, Áras de Brún, National University of Ireland Galway (NUIG), Research Road, Galway, H91TK33, Ireland
| | - Rachel L Doran
- Centre for Agriculture and the Bioeconomy, Institute for Future Environments, Queensland University of Technology (QUT), 2 George Street, Brisbane, QLD, 4000, Australia
| | - Sally Roden
- Centre for Agriculture and the Bioeconomy, Institute for Future Environments, Queensland University of Technology (QUT), 2 George Street, Brisbane, QLD, 4000, Australia
| | - Andrew L Eamens
- School of Environmental and Life Sciences, The University of Newcastle, Callaghan, NSW, 2308, Australia
| | - E Jean Finnegan
- CSIRO Agriculture and Food, GPO Box 1700, Canberra, ACT, 2601, Australia
| | - Peter M Waterhouse
- Centre for Agriculture and the Bioeconomy, Institute for Future Environments, Queensland University of Technology (QUT), 2 George Street, Brisbane, QLD, 4000, Australia
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24
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Lee YA, Im SW, Jung KC, Chung EJ, Shin CH, Kim JI, Park YJ. Predominant DICER1 Pathogenic Variants in Pediatric Follicular Thyroid Carcinomas. Thyroid 2020; 30:1120-1131. [PMID: 32228164 DOI: 10.1089/thy.2019.0233] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Background: Pediatric thyroid cancer has characteristics that are distinct from adulthood thyroid cancer. Due to its very low prevalence, little is known about the genetic characteristics of pediatric follicular thyroid cancer (FTC). Methods: We investigated genetic alterations in tumor tissues from 15 patients aged <20 years (median: 14.3 years; range: 2.4 - 19.0 years) using multifaceted approaches. Whole-exome sequencing, targeted next-generation sequencing using a cancer gene panel, and Sanger sequencing of the major exons of the H/K/N-RAS and DICER1 genes and the promoter region of the TERT gene were performed. Normal tissues or blood of patients with DICER1- or PTEN-positive tumors was also evaluated to determine whether the variant is germ line. Results: The median tumor size was 3.1 cm (range: 0.6 - 6.4 cm). Four patients exhibited angioinvasion and one extensive capsular invasion; none showed evidence of disease over a median of 8.1 years. Eight patients (53.3%) had DICER1 variants, including four with DICER1 syndrome (three patients were <10 years of age). One patient had a germ line PTEN frameshift variant with the diagnosis of PTEN hamartoma tumor syndrome. One patient had a PAX8/PPARγ rearrangement, and two patients had no genetic driver alteration other than multiple loss of heterozygosity with or without copy number alterations in their tumors. No RAS or TERT variants were found. Nodular hyperplasia and follicular adenoma (FA) coexisted in DICER1 variant-positive FTCs more frequently than variant-negative FTCs (p = 0.026). All DICER1 variant-positive FTCs had a somatic missense variant at metal binding sites (six at codon p.E1813 and two at codon p.D1709) within the RNase IIIb domain; seven had other missense, nonsense, or frameshift variants in the DICER1 gene. Six coexisting FAs of two patients with DICER1 syndrome (three of each) had additional somatic variants at metal binding sites within the RNase IIIb domain (codon p.E1705, p.D1709, p.D1810, or p.E1813), different from each other and from the indexed FTC tumor. Conclusions: Pediatric FTCs have distinct genomic alterations and pathogenesis compared with adults, particularly those characterized by DICER1 variants. The DICER1 variant should be considered in pediatric FTCs, especially in cases <10 years of age. In all DICER1 variant-positive FTCs and FAs, recurrent hotspot variants were found at metal binding sites within the RNase IIIb domain, suggesting they impact tumorigenesis.
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Affiliation(s)
- Young Ah Lee
- Department of Pediatrics, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Sun-Wha Im
- Genomic Medicine Institute, Medical Research Center, Seoul National University, Seoul, Republic of Korea
| | - Kyeong Cheon Jung
- Department of Pathology, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Eun-Jae Chung
- Department of Otorhinolaryngology-Head and Neck Surgery, and Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Choong Ho Shin
- Department of Pediatrics, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Jong-Il Kim
- Genomic Medicine Institute, Medical Research Center, Seoul National University, Seoul, Republic of Korea
- Department of Biomedical Sciences, Seoul National University Graduate School, Seoul, Republic of Korea
- Seoul National University Cancer Research Institute, Seoul, Republic of Korea
| | - Young Joo Park
- Seoul National University Cancer Research Institute, Seoul, Republic of Korea
- Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea
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25
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Dubey H, Kiran K, Jaswal R, Bhardwaj SC, Mondal TK, Jain N, Singh NK, Kayastha AM, Sharma TR. Identification and characterization of Dicer-like genes in leaf rust pathogen (Puccinia triticina) of wheat. Funct Integr Genomics 2020; 20:711-721. [PMID: 32705366 DOI: 10.1007/s10142-020-00745-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Revised: 06/25/2020] [Accepted: 06/29/2020] [Indexed: 10/23/2022]
Abstract
Puccinia triticina (P. triticina) is one of the most devastating fungal pathogens of wheat which causes significant annual yield loss to the crop. Understanding the gene regulatory mechanism of the biotrophic pathogen is one of the important aspects of host-pathogen interaction studies. Dicer-like genes are considered as important mediators of RNAi-based gene regulation. In this study, we report the presence of three Dicer-like genes (Pt-DCL1, Pt-DCL2, Pt-DCL3) in P. triticina genome identified through computational and biological analyses. Quantitative real-time PCR studies revealed an increase in the expression of these genes in germinating spore stages. Heterologous expression combined with mass spectrometry analysis of Pt-DCL2 confirmed the presence of a canonical Dicer-like gene in P. triticina. Phylogenetic analysis of the Pt-DCLs with the Dicer-like proteins from other organisms showed a distinct cluster of rust pathogens from the order Pucciniales. The results indicated a species-specific duplication of Dicer-like genes within the wheat rust pathogens. This study, for the first time, reports the presence of Dicer-dependent RNAi pathway in P. triticina that may play a role in gene regulatory mechanism of the pathogen during its development. Our study serves as a vital source of information for further RNAi-based molecular studies for better understanding and management of the wheat leaf rust disease.
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Affiliation(s)
- Himanshu Dubey
- ICAR-National Institute for Plant Biotechnology (formerly ICAR-National Research Centre on Plant Biotechnology), Pusa Campus, New Delhi, 110012, India.,School of Biotechnology, Institute of Science, Banaras Hindu University, Varanasi, 221005, India.,Seri-Biotech Research Laboratory, Central Silk Board, Bangalore, Karnataka, 560035, India
| | - Kanti Kiran
- ICAR-National Institute for Plant Biotechnology (formerly ICAR-National Research Centre on Plant Biotechnology), Pusa Campus, New Delhi, 110012, India
| | - Rajdeep Jaswal
- ICAR-National Institute for Plant Biotechnology (formerly ICAR-National Research Centre on Plant Biotechnology), Pusa Campus, New Delhi, 110012, India
| | - Subhash C Bhardwaj
- ICAR-Indian Institute of Wheat and Barley Research, Regional Station, Flowerdale, Shimla, 171009, India
| | - Tapan Kumar Mondal
- ICAR-National Institute for Plant Biotechnology (formerly ICAR-National Research Centre on Plant Biotechnology), Pusa Campus, New Delhi, 110012, India
| | - Neha Jain
- ICAR-National Institute for Plant Biotechnology (formerly ICAR-National Research Centre on Plant Biotechnology), Pusa Campus, New Delhi, 110012, India
| | - N K Singh
- ICAR-National Institute for Plant Biotechnology (formerly ICAR-National Research Centre on Plant Biotechnology), Pusa Campus, New Delhi, 110012, India
| | - Arvind M Kayastha
- School of Biotechnology, Institute of Science, Banaras Hindu University, Varanasi, 221005, India.
| | - Tilak Raj Sharma
- ICAR-National Institute for Plant Biotechnology (formerly ICAR-National Research Centre on Plant Biotechnology), Pusa Campus, New Delhi, 110012, India. .,Indian Council of Agricultural Research, Krishi Bhawan, New Delhi, 110001, India.
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26
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Wang H, Cao Q, Zhao Q, Arfan M, Liu W. Mechanisms used by DNA MMR system to cope with Cadmium-induced DNA damage in plants. CHEMOSPHERE 2020; 246:125614. [PMID: 31883478 DOI: 10.1016/j.chemosphere.2019.125614] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2019] [Revised: 12/07/2019] [Accepted: 12/09/2019] [Indexed: 05/27/2023]
Abstract
Cadmium (Cd) is found widely in soil and is severely toxic for plants, causing oxidative damage in plant cells because of its heavy metal characteristics. The DNA damage response (DDR) is triggered in plants to cope with the Cd stress. The DNA mismatch repair (MMR) system known for its mismatch repair function determines DDR, as mispairs are easily generated by a translesional synthesis under Cd-induced genomic instability. Cd-induced mismatches are recognized by three heterodimeric complexes including MutSα (MSH2/MSH6), MutSβ (MSH2/MSH3), and MutSγ (MSH2/MSH7). MutLα (MLH1/PMS1), PCNA/RFC, EXO1, DNA polymerase δ and DNA ligase participate in mismatch repair in turn. Meanwhile, ATR is preferentially activated by MSH2 to trigger DDR including the regulation of the cell cycle, endoreduplication, cell death, and recruitment of other DNA repair, which enhances plant tolerance to Cd. However, plants with deficient MutS will bypass MMR-mediated DDR and release the multiple-effect MLH1 from requisition of the MMR system, which leads to weak tolerance to Cd in plants. In this review, we systematically illustrate how the plant DNA MMR system works in a Cd-induced DDR, and how MMR genes regulate plant tolerance to Cd. Additionally, we also reviewed multiple epigenetic regulation systems acting on MMR genes under stress.
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Affiliation(s)
- Hetong Wang
- Liaoning Key Laboratory of Urban Integrated Pest Management and Ecological Security, College of Life Science and Bioengineering, Shenyang University, Shenyang, 110044, PR China.
| | - Qijiang Cao
- Liaoning Key Laboratory of Urban Integrated Pest Management and Ecological Security, College of Life Science and Bioengineering, Shenyang University, Shenyang, 110044, PR China.
| | - Qiang Zhao
- Agricultural College, Shenyang Agricultural University, Shenyang, 110866, PR China.
| | - Muhammad Arfan
- Key Laboratory of Pollution Ecology and Environmental Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110016, PR China.
| | - Wan Liu
- Key Laboratory of Pollution Ecology and Environmental Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110016, PR China.
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27
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Robinson EK, Covarrubias S, Carpenter S. The how and why of lncRNA function: An innate immune perspective. BIOCHIMICA ET BIOPHYSICA ACTA. GENE REGULATORY MECHANISMS 2020; 1863:194419. [PMID: 31487549 PMCID: PMC7185634 DOI: 10.1016/j.bbagrm.2019.194419] [Citation(s) in RCA: 181] [Impact Index Per Article: 45.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Accepted: 08/21/2019] [Indexed: 02/06/2023]
Abstract
Next-generation sequencing has provided a more complete picture of the composition of the human transcriptome indicating that much of the "blueprint" is a vastness of poorly understood non-protein-coding transcripts. This includes a newly identified class of genes called long noncoding RNAs (lncRNAs). The lack of sequence conservation for lncRNAs across species meant that their biological importance was initially met with some skepticism. LncRNAs mediate their functions through interactions with proteins, RNA, DNA, or a combination of these. Their functions can often be dictated by their localization, sequence, and/or secondary structure. Here we provide a review of the approaches typically adopted to study the complexity of these genes with an emphasis on recent discoveries within the innate immune field. Finally, we discuss the challenges, as well as the emergence of new technologies that will continue to move this field forward and provide greater insight into the biological importance of this class of genes. This article is part of a Special Issue entitled: ncRNA in control of gene expression edited by Kotb Abdelmohsen.
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Affiliation(s)
- Elektra K Robinson
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, Santa Cruz, CA, United States of America
| | - Sergio Covarrubias
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, Santa Cruz, CA, United States of America
| | - Susan Carpenter
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, Santa Cruz, CA, United States of America.
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28
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Domingo-Prim J, Bonath F, Visa N. RNA at DNA Double-Strand Breaks: The Challenge of Dealing with DNA:RNA Hybrids. Bioessays 2020; 42:e1900225. [PMID: 32105369 DOI: 10.1002/bies.201900225] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2019] [Revised: 02/02/2020] [Indexed: 12/12/2022]
Abstract
RNA polymerase II is recruited to DNA double-strand breaks (DSBs), transcribes the sequences that flank the break and produces a novel RNA type that has been termed damage-induced long non-coding RNA (dilncRNA). DilncRNAs can be processed into short, miRNA-like molecules or degraded by different ribonucleases. They can also form double-stranded RNAs or DNA:RNA hybrids. The DNA:RNA hybrids formed at DSBs contribute to the recruitment of repair factors during the early steps of homologous recombination (HR) and, in this way, contribute to the accuracy of the DNA repair. However, if not resolved, the DNA:RNA hybrids are highly mutagenic and prevent the recruitment of later HR factors. Here recent discoveries about the synthesis, processing, and degradation of dilncRNAs are revised. The focus is on RNA clearance, a necessary step for the successful repair of DSBs and the aim is to reconcile contradictory findings on the effects of dilncRNAs and DNA:RNA hybrids in HR.
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Affiliation(s)
- Judit Domingo-Prim
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, SE-106 91, Stockholm, Sweden.,Moirai Biodesign SL, Parc Científic de Barcelona, E-08028, Barcelona, Spain
| | - Franziska Bonath
- Science for Life Laboratory, National Genomics Infrastructure, Department of Biochemistry and Biophysics, Stockholm University, SE-106 91, Stockholm, Sweden
| | - Neus Visa
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, SE-106 91, Stockholm, Sweden
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29
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Gutbrod MJ, Martienssen RA. Conserved chromosomal functions of RNA interference. Nat Rev Genet 2020; 21:311-331. [PMID: 32051563 DOI: 10.1038/s41576-019-0203-6] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/26/2019] [Indexed: 12/21/2022]
Abstract
RNA interference (RNAi), a cellular process through which small RNAs target and regulate complementary RNA transcripts, has well-characterized roles in post-transcriptional gene regulation and transposon repression. Recent studies have revealed additional conserved roles for RNAi proteins, such as Argonaute and Dicer, in chromosome function. By guiding chromatin modification, RNAi components promote chromosome segregation during both mitosis and meiosis and regulate chromosomal and genomic dosage response. Small RNAs and the RNAi machinery also participate in the resolution of DNA damage. Interestingly, many of these lesser-studied functions seem to be more strongly conserved across eukaryotes than are well-characterized functions such as the processing of microRNAs. These findings have implications for the evolution of RNAi since the last eukaryotic common ancestor, and they provide a more complete view of the functions of RNAi.
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Affiliation(s)
- Michael J Gutbrod
- Watson School of Biological Sciences, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA
| | - Robert A Martienssen
- Watson School of Biological Sciences, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA. .,Howard Hughes Medical Institute, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA.
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30
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Stolyarenko AD. Nuclear Argonaute Piwi Gene Mutation Affects rRNA by Inducing rRNA Fragment Accumulation, Antisense Expression, and Defective Processing in Drosophila Ovaries. Int J Mol Sci 2020; 21:ijms21031119. [PMID: 32046213 PMCID: PMC7037970 DOI: 10.3390/ijms21031119] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 01/27/2020] [Accepted: 02/04/2020] [Indexed: 12/26/2022] Open
Abstract
Drosophila key nuclear piRNA silencing pathway protein Piwi of the Argonaute family has been classically studied as a factor controlling transposable elements and fertility. Piwi has been shown to concentrate in the nucleolus for reasons largely unknown. Ribosomal RNA is the main component of the nucleolus. In this work the effect of a piwi mutation on rRNA is described. This work led to three important conclusions: A mutation in piwi induces antisense 5S rRNA expression, a processing defect of 2S rRNA orthologous to the 3′-end of eukaryotic 5.8S rRNA, and accumulation of fragments of all five rRNAs in Drosophilamelanogaster ovaries. Hypotheses to explain these phenomena are proposed, possibly involving the interaction of the components of the piRNA pathway with the RNA surveillance machinery.
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Affiliation(s)
- Anastasia D Stolyarenko
- Institute of Molecular Genetics, Russian Academy of Sciences, 2 Kurchatov Sq., Moscow 123182, Russia
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31
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Lambo S, Gröbner SN, Rausch T, Waszak SM, Schmidt C, Gorthi A, Romero JC, Mauermann M, Brabetz S, Krausert S, Buchhalter I, Koster J, Zwijnenburg DA, Sill M, Hübner JM, Mack N, Schwalm B, Ryzhova M, Hovestadt V, Papillon-Cavanagh S, Chan JA, Landgraf P, Ho B, Milde T, Witt O, Ecker J, Sahm F, Sumerauer D, Ellison DW, Orr BA, Darabi A, Haberler C, Figarella-Branger D, Wesseling P, Schittenhelm J, Remke M, Taylor MD, Gil-da-Costa MJ, Łastowska M, Grajkowska W, Hasselblatt M, Hauser P, Pietsch T, Uro-Coste E, Bourdeaut F, Masliah-Planchon J, Rigau V, Alexandrescu S, Wolf S, Li XN, Schüller U, Snuderl M, Karajannis MA, Giangaspero F, Jabado N, von Deimling A, Jones DTW, Korbel JO, von Hoff K, Lichter P, Huang A, Bishop AJR, Pfister SM, Korshunov A, Kool M. The molecular landscape of ETMR at diagnosis and relapse. Nature 2019; 576:274-280. [PMID: 31802000 PMCID: PMC6908757 DOI: 10.1038/s41586-019-1815-x] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Accepted: 10/16/2019] [Indexed: 12/18/2022]
Abstract
Embryonal tumours with multilayered rosettes (ETMRs) are aggressive paediatric embryonal brain tumours with a universally poor prognosis1. Here we collected 193 primary ETMRs and 23 matched relapse samples to investigate the genomic landscape of this distinct tumour type. We found that patients with tumours in which the proposed driver C19MC2-4 was not amplified frequently had germline mutations in DICER1 or other microRNA-related aberrations such as somatic amplification of miR-17-92 (also known as MIR17HG). Whole-genome sequencing revealed that tumours had an overall low recurrence of single-nucleotide variants (SNVs), but showed prevalent genomic instability caused by widespread occurrence of R-loop structures. We show that R-loop-associated chromosomal instability can be induced by the loss of DICER1 function. Comparison of primary tumours and matched relapse samples showed a strong conservation of structural variants, but low conservation of SNVs. Moreover, many newly acquired SNVs are associated with a mutational signature related to cisplatin treatment. Finally, we show that targeting R-loops with topoisomerase and PARP inhibitors might be an effective treatment strategy for this deadly disease.
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Affiliation(s)
- Sander Lambo
- Hopp Children's Cancer Center (KiTZ), Heidelberg, Germany
- Division of Pediatric Neurooncology, German Cancer Research Center (DKFZ), Heidelberg, Germany
- German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Susanne N Gröbner
- Hopp Children's Cancer Center (KiTZ), Heidelberg, Germany
- Division of Pediatric Neurooncology, German Cancer Research Center (DKFZ), Heidelberg, Germany
- German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Tobias Rausch
- European Molecular Biology Laboratory (EMBL), Genome Biology Unit, Heidelberg, Germany
| | - Sebastian M Waszak
- European Molecular Biology Laboratory (EMBL), Genome Biology Unit, Heidelberg, Germany
| | - Christin Schmidt
- Hopp Children's Cancer Center (KiTZ), Heidelberg, Germany
- Division of Pediatric Neurooncology, German Cancer Research Center (DKFZ), Heidelberg, Germany
- German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Aparna Gorthi
- Department of Cell Systems and Anatomy, University of Texas Health at San Antonio, San Antonio, TX, USA
- Greehey Children's Cancer Research Institute, University of Texas Health at San Antonio, San Antonio, TX, USA
| | - July Carolina Romero
- Department of Cell Systems and Anatomy, University of Texas Health at San Antonio, San Antonio, TX, USA
- Greehey Children's Cancer Research Institute, University of Texas Health at San Antonio, San Antonio, TX, USA
| | - Monika Mauermann
- Hopp Children's Cancer Center (KiTZ), Heidelberg, Germany
- Division of Pediatric Neurooncology, German Cancer Research Center (DKFZ), Heidelberg, Germany
- German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Sebastian Brabetz
- Hopp Children's Cancer Center (KiTZ), Heidelberg, Germany
- Division of Pediatric Neurooncology, German Cancer Research Center (DKFZ), Heidelberg, Germany
- German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Sonja Krausert
- Hopp Children's Cancer Center (KiTZ), Heidelberg, Germany
- Division of Pediatric Neurooncology, German Cancer Research Center (DKFZ), Heidelberg, Germany
- German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Ivo Buchhalter
- Omics IT and Data Management Core Facility, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Jan Koster
- Department of Oncogenomics, Academic Medical Center, Amsterdam, The Netherlands
| | - Danny A Zwijnenburg
- Department of Oncogenomics, Academic Medical Center, Amsterdam, The Netherlands
| | - Martin Sill
- Hopp Children's Cancer Center (KiTZ), Heidelberg, Germany
- Division of Pediatric Neurooncology, German Cancer Research Center (DKFZ), Heidelberg, Germany
- German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Jens-Martin Hübner
- Hopp Children's Cancer Center (KiTZ), Heidelberg, Germany
- Division of Pediatric Neurooncology, German Cancer Research Center (DKFZ), Heidelberg, Germany
- German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Norman Mack
- Hopp Children's Cancer Center (KiTZ), Heidelberg, Germany
- Division of Pediatric Neurooncology, German Cancer Research Center (DKFZ), Heidelberg, Germany
- German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Benjamin Schwalm
- Hopp Children's Cancer Center (KiTZ), Heidelberg, Germany
- Division of Pediatric Neurooncology, German Cancer Research Center (DKFZ), Heidelberg, Germany
- German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Marina Ryzhova
- Department of Neuropathology, NN Burdenko Neurosurgical Institute, Moscow, Russia
| | - Volker Hovestadt
- Division of Molecular Genetics, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Simon Papillon-Cavanagh
- Department of Pediatrics, McGill University Health Center, McGill University, Montreal, Quebec, Canada
| | - Jennifer A Chan
- Department of Pathology and Laboratory Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Pablo Landgraf
- Department of Pediatrics, Pediatric Oncology and Hematology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Ben Ho
- Division of Hematology/Oncology Arthur and Sonia Labatt Brain Tumour Research Centre, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Till Milde
- Hopp Children's Cancer Center (KiTZ), Heidelberg, Germany
- German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), Heidelberg, Germany
- Clinical Cooperation Unit Pediatric Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany
- Department of Pediatric Oncology, Hematology and Immunology, Heidelberg University Hospital, Heidelberg, Germany
| | - Olaf Witt
- Hopp Children's Cancer Center (KiTZ), Heidelberg, Germany
- German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), Heidelberg, Germany
- Clinical Cooperation Unit Pediatric Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany
- Department of Pediatric Oncology, Hematology and Immunology, Heidelberg University Hospital, Heidelberg, Germany
| | - Jonas Ecker
- Hopp Children's Cancer Center (KiTZ), Heidelberg, Germany
- Clinical Cooperation Unit Pediatric Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany
- Department of Pediatric Oncology, Hematology and Immunology, Heidelberg University Hospital, Heidelberg, Germany
| | - Felix Sahm
- Hopp Children's Cancer Center (KiTZ), Heidelberg, Germany
- German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), Heidelberg, Germany
- Department of Neuropathology, Heidelberg University Hospital, Heidelberg, Germany
- Clinical Cooperation Unit Neuropathology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - David Sumerauer
- Department of Pediatric Hematology and Oncology, University Hospital Motol, Prague, Czech Republic
| | - David W Ellison
- Department of Pathology, St Jude Children's Research Hospital, Memphis, TN, USA
| | - Brent A Orr
- Department of Pathology, St Jude Children's Research Hospital, Memphis, TN, USA
| | - Anna Darabi
- Department of Clinical Sciences Lund, Section of Neurosurgery, Faculty of Medicine, Lund University, Lund, Sweden
| | | | - Dominique Figarella-Branger
- Aix-Marseille University, Neurophysiopathology Institute (INP), CNRS, Marseille, France
- Department of Pathology, APHM, Marseille, France
| | - Pieter Wesseling
- Princess Máxima Center for Pediatric Oncology, Utrecht, The Netherlands
- Department of Pathology, Amsterdam University Medical Centers/location VUmc, Amsterdam, The Netherlands
| | - Jens Schittenhelm
- Department of Neuropathology, Institute of Pathology and Neuropathology, University Hospital of Tübingen, Tübingen, Germany
- Center for CNS Tumors, Comprehensive Cancer Center Tübingen-Stuttgart, University Hospital of Tübingen, Tübingen, Germany
| | - Marc Remke
- German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), Heidelberg, Germany
- Department of Pediatric Oncology, Hematology and Clinical Immunology, Medical Faculty, University Hospital Düsseldorf, Düsseldorf, Germany
- Division of Neurosurgery, Arthur and Sonia Labatt Brain Tumor Research Center, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | - Michael D Taylor
- Division of Neurosurgery, Arthur and Sonia Labatt Brain Tumor Research Center, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | - Maria J Gil-da-Costa
- Pediatric Hematology and Oncology Division, University Hospital São João Alameda Hernani Monteiro, Porto, Portugal
| | - Maria Łastowska
- Department of Pathology, Children's Memorial Health Institute, Warsaw, Poland
| | - Wiesława Grajkowska
- Department of Pathology, Children's Memorial Health Institute, Warsaw, Poland
| | - Martin Hasselblatt
- Institute of Neuropathology, University Hospital Münster, Münster, Germany
| | - Peter Hauser
- 2nd Department of Pediatrics, Semmelweis University, Budapest, Hungary
| | - Torsten Pietsch
- Institute of Neuropathology, Brain Tumor Reference Center of the German Society of Neuropathology and Neuroanatomy, University of Bonn Medical Center, Bonn, Germany
| | - Emmanuelle Uro-Coste
- Department of Pathology, Toulouse University Hospital, Toulouse, France
- INSERM U1037, Cancer Research Center of Toulouse (CRCT), Toulouse, France
| | - Franck Bourdeaut
- INSERM U830, Laboratory of Translational Research in Pediatric Oncology, SIREDO Pediatric Oncology Center, Paris Sciences Lettres Research University, Curie Institute, Paris, France
| | - Julien Masliah-Planchon
- Pediatric Oncology Department, SIREDO Pediatric Oncology Centre, Curie Institute, Paris, France
- Paris Sciences et Lettres Research University, Institut Curie Hospital, Laboratory of Somatic Genetics, Paris, France
| | - Valérie Rigau
- Department of Pathology, Montpellier University Medical Center, Montpellier, France
- Institute for Neuroscience of Montpellier (INM), INSERM U1051, Montpellier University Hospital, Montpellier, France
| | - Sanda Alexandrescu
- Department of Pathology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Stephan Wolf
- Genomics and Proteomics Core Facility, High Throughput Sequencing Unit, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Xiao-Nan Li
- Brain Tumor Program, Texas Children's Cancer Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA
- Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, IL, USA
- Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Ulrich Schüller
- Institute of Neuropathology, University Medical Center, Hamburg-Eppendorf, Hamburg, Germany
- Research Institute Children's Cancer Center, Hamburg, Germany
- Department of Pediatric Hematology and Oncology, University Medical Center, Hamburg-Eppendorf, Hamburg, Germany
| | - Matija Snuderl
- Department of Pathology, NYU Langone Health, New York, NY, USA
| | - Matthias A Karajannis
- Division of Pediatric Hematology/Oncology, NYU Langone Medical Center, The Stephen D. Hassenfeld Children's Center for Cancer and Blood Disorders, New York, NY, USA
| | - Felice Giangaspero
- Department of Radiological, Oncological and Anatomopathological Sciences, Sapienza University of Rome, Rome, Italy
- IRCCS Neuromed-Mediterranean Neurological Institute, Pozzilli, Italy
| | - Nada Jabado
- Department of Pediatrics, McGill University Health Center, McGill University, Montreal, Quebec, Canada
| | - Andreas von Deimling
- Hopp Children's Cancer Center (KiTZ), Heidelberg, Germany
- Department of Neuropathology, Heidelberg University Hospital, Heidelberg, Germany
- Clinical Cooperation Unit Neuropathology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - David T W Jones
- Hopp Children's Cancer Center (KiTZ), Heidelberg, Germany
- German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), Heidelberg, Germany
- Pediatric Glioma Research Group, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Jan O Korbel
- European Molecular Biology Laboratory (EMBL), Genome Biology Unit, Heidelberg, Germany
| | - Katja von Hoff
- Department of Pediatric Oncology/Hematology, Charité University Medicine, Berlin, Germany
- Department for Pediatric Hematology and Oncology, University Hospital Hamburg-Eppendorf, Hamburg, Germany
| | - Peter Lichter
- German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), Heidelberg, Germany
- Division of Molecular Genetics, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Annie Huang
- Division of Hematology/Oncology Arthur and Sonia Labatt Brain Tumour Research Centre, The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Pediatrics, Medical Biophysics, Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
| | - Alexander J R Bishop
- Department of Cell Systems and Anatomy, University of Texas Health at San Antonio, San Antonio, TX, USA
- Greehey Children's Cancer Research Institute, University of Texas Health at San Antonio, San Antonio, TX, USA
- Mays Cancer Center, University of Texas Health at San Antonio, San Antonio, TX, USA
| | - Stefan M Pfister
- Hopp Children's Cancer Center (KiTZ), Heidelberg, Germany
- Division of Pediatric Neurooncology, German Cancer Research Center (DKFZ), Heidelberg, Germany
- German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), Heidelberg, Germany
- Department of Pediatric Oncology, Hematology and Immunology, Heidelberg University Hospital, Heidelberg, Germany
| | - Andrey Korshunov
- Department of Neuropathology, Heidelberg University Hospital, Heidelberg, Germany
- Clinical Cooperation Unit Neuropathology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Marcel Kool
- Hopp Children's Cancer Center (KiTZ), Heidelberg, Germany.
- Division of Pediatric Neurooncology, German Cancer Research Center (DKFZ), Heidelberg, Germany.
- German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), Heidelberg, Germany.
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Nakazawa N, Arakawa O, Yanagida M. Condensin locates at transcriptional termination sites in mitosis, possibly releasing mitotic transcripts. Open Biol 2019; 9:190125. [PMID: 31615333 PMCID: PMC6833218 DOI: 10.1098/rsob.190125] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
Condensin is an essential component of chromosome dynamics, including mitotic chromosome condensation and segregation, DNA repair, and development. Genome-wide localization of condensin is known to correlate with transcriptional activity. The functional relationship between condensin accumulation and transcription sites remains unclear, however. By constructing the auxin-inducible degron strain of condensin, herein we demonstrate that condensin does not affect transcription itself. Instead, RNA processing at transcriptional termination appears to define condensin accumulation sites during mitosis, in the fission yeast Schizosaccharomyces pombe. Combining the auxin-degron strain with the nda3 β-tubulin cold-sensitive (cs) mutant enabled us to inactivate condensin in mitotically arrested cells, without releasing the cells into anaphase. Transcriptional activation and termination were not affected by condensin's degron-mediated depletion, at heat-shock inducible genes or mitotically activated genes. On the other hand, condensin accumulation sites shifted approximately 500 bp downstream in the auxin-degron of 5′-3′ exoribonuclease Dhp1, in which transcripts became aberrantly elongated, suggesting that condensin accumulates at transcriptionally terminated DNA regions. Growth defects in mutant strains of 3′-processing ribonuclease and polyA cleavage factors were additive in condensin temperature-sensitive (ts) mutants. Considering condensin's in vitro activity to form double-stranded DNAs from unwound, single-stranded DNAs or DNA-RNA hybrids, condensin-mediated processing of mitotic transcripts at the 3′-end may be a prerequisite for faithful chromosome segregation.
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Affiliation(s)
- Norihiko Nakazawa
- Okinawa Institute of Science and Technology Graduate University, G0 Cell Unit, Onna-son, Okinawa 904-0495, Japan
| | - Orie Arakawa
- Okinawa Institute of Science and Technology Graduate University, G0 Cell Unit, Onna-son, Okinawa 904-0495, Japan
| | - Mitsuhiro Yanagida
- Okinawa Institute of Science and Technology Graduate University, G0 Cell Unit, Onna-son, Okinawa 904-0495, Japan
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33
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R Loops: From Physiological to Pathological Roles. Cell 2019; 179:604-618. [PMID: 31607512 DOI: 10.1016/j.cell.2019.08.055] [Citation(s) in RCA: 364] [Impact Index Per Article: 72.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Revised: 08/19/2019] [Accepted: 08/28/2019] [Indexed: 12/13/2022]
Abstract
DNA-RNA hybrids play a physiological role in cellular processes, but often, they represent non-scheduled co-transcriptional structures with a negative impact on transcription, replication and DNA repair. Accumulating evidence suggests that they constitute a source of replication stress, DNA breaks and genome instability. Reciprocally, DNA breaks facilitate DNA-RNA hybrid formation by releasing the double helix torsional conformation. Cells avoid DNA-RNA accumulation by either preventing or removing hybrids directly or by DNA repair-coupled mechanisms. Given the R-loop impact on chromatin and genome organization and its potential relation with genetic diseases, we review R-loop homeostasis as well as their physiological and pathological roles.
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Abstract
Human germ cell tumours (GCTs) are derived from stem cells of the early embryo and the germ line. They occur in the gonads (ovaries and testes) and also in extragonadal sites, where migrating primordial germ cells are located during embryogenesis. This group of heterogeneous neoplasms is unique in that their developmental potential is in effect determined by the latent potency state of their cells of origin, which are reprogrammed to omnipotent, totipotent or pluripotent stem cells. Seven GCT types, defined according to their developmental potential, have been identified, each with distinct epidemiological and (epi)genomic features. Heritable predisposition factors affecting the cells of origin and their niches likely explain bilateral, multiple and familial occurrences of the different types of GCTs. Unlike most other tumour types, GCTs are rarely caused by somatic driver mutations, but arise through failure to control the latent developmental potential of their cells of origin, resulting in their reprogramming. Consistent with their non-mutational origin, even the malignant tumours of the group are characterized by wild-type TP53 and high sensitivity for DNA damage. However, tumour progression and the rare occurrence of treatment resistance are driven by embryonic epigenetic state, specific (sub)chromosomal imbalances and somatic mutations. Thus, recent progress in understanding GCT biology supports a comprehensive developmental pathogenetic model for the origin of all GCTs, and provides new biomarkers, as well as potential targets for treatment of resistant disease.
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Affiliation(s)
- J Wolter Oosterhuis
- Laboratory for Experimental Patho-Oncology, Department of Pathology, Erasmus MC Cancer Institute, Rotterdam, Netherlands.
| | - Leendert H J Looijenga
- Laboratory for Experimental Patho-Oncology, Department of Pathology, Erasmus MC Cancer Institute, Rotterdam, Netherlands
- Princess Máxima Center for Pediatric Oncology, Utrecht, The Netherlands
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Fragkos M, Barra V, Egger T, Bordignon B, Lemacon D, Naim V, Coquelle A. Dicer prevents genome instability in response to replication stress. Oncotarget 2019; 10:4407-4423. [PMID: 31320994 PMCID: PMC6633883 DOI: 10.18632/oncotarget.27034] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Accepted: 06/05/2019] [Indexed: 11/25/2022] Open
Abstract
Dicer, an endoribonuclease best-known for its role in microRNA biogenesis and RNA interference pathway, has been shown to play a role in the DNA damage response and repair of double-stranded DNA breaks (DSBs) in mammalian cells. However, it remains unknown whether Dicer is also important to preserve genome integrity upon replication stress. To address this question, we focused our study on common fragile sites (CFSs), which are susceptible to breakage after replication stress. We show that inhibition of the Dicer pathway leads to an increase in CFS expression upon induction of replication stress and to an accumulation of 53BP1 nuclear bodies, indicating transmission of replication-associated damage. We also show that in absence of a functional Dicer or Drosha, the assembly into nuclear foci of the Fanconi anemia (FA) protein FANCD2 and of the replication and checkpoint factor TopBP1 in response to replication stress is impaired, and the activation of the S-phase checkpoint is defective. Based on these results, we propose that Dicer pre-vents genomic instability after replication stress, by allowing the proper recruitment to stalled forks of proteins that are necessary to maintain replication fork stability and activate the S-phase checkpoint, thus limiting cells from proceeding into mitosis with under-replicated DNA.
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Affiliation(s)
- Michalis Fragkos
- IRCM, Institut de Recherche en Cancérologie de Montpellier, INSERM U1194, Université de Montpellier, Institut Régional du Cancer de Montpellier, Montpellier, France.,Laboratory of Genetic Instability and Oncogenesis, UMR 8200 CNRS, University Paris-Sud, Gustave Roussy, Villejuif, France.,These authors contributed equally to this work
| | - Viviana Barra
- Laboratory of Genetic Instability and Oncogenesis, UMR 8200 CNRS, University Paris-Sud, Gustave Roussy, Villejuif, France.,These authors contributed equally to this work
| | - Tom Egger
- IRCM, Institut de Recherche en Cancérologie de Montpellier, INSERM U1194, Université de Montpellier, Institut Régional du Cancer de Montpellier, Montpellier, France
| | - Benoit Bordignon
- IRCM, Institut de Recherche en Cancérologie de Montpellier, INSERM U1194, Université de Montpellier, Institut Régional du Cancer de Montpellier, Montpellier, France
| | - Delphine Lemacon
- IRCM, Institut de Recherche en Cancérologie de Montpellier, INSERM U1194, Université de Montpellier, Institut Régional du Cancer de Montpellier, Montpellier, France.,Present address: Department of Biochemistry and Molecular Biology, Doisy Research Center, St. Louis, MO, USA
| | - Valeria Naim
- Laboratory of Genetic Instability and Oncogenesis, UMR 8200 CNRS, University Paris-Sud, Gustave Roussy, Villejuif, France.,These authors contributed equally to this work
| | - Arnaud Coquelle
- IRCM, Institut de Recherche en Cancérologie de Montpellier, INSERM U1194, Université de Montpellier, Institut Régional du Cancer de Montpellier, Montpellier, France
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Bonath F, Domingo-Prim J, Tarbier M, Friedländer MR, Visa N. Next-generation sequencing reveals two populations of damage-induced small RNAs at endogenous DNA double-strand breaks. Nucleic Acids Res 2019; 46:11869-11882. [PMID: 30418607 PMCID: PMC6294500 DOI: 10.1093/nar/gky1107] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Accepted: 10/22/2018] [Indexed: 12/20/2022] Open
Abstract
Recent studies suggest that transcription takes place at DNA double-strand breaks (DSBs), that transcripts at DSBs are processed by Drosha and Dicer into damage-induced small RNAs (diRNAs), and that diRNAs are required for DNA repair. However, diRNAs have been mostly detected in reporter constructs or repetitive sequences, and their existence at endogenous loci has been questioned by recent reports. Using the homing endonuclease I-PpoI, we have investigated diRNA production in genetically unperturbed human and mouse cells. I-PpoI is an ideal tool to clarify the requirements for diRNA production because it induces DSBs in different types of loci: the repetitive 28S locus, unique genes and intergenic loci. We show by extensive sequencing that the rDNA locus produces substantial levels of diRNAs, whereas unique genic and intergenic loci do not. Further characterization of diRNAs emerging from the 28S locus reveals the existence of two diRNA subtypes. Surprisingly, Drosha and its partner DGCR8 are dispensable for diRNA production and only one diRNAs subtype depends on Dicer processing. Furthermore, we provide evidence that diRNAs are incorporated into Argonaute. Our findings provide direct evidence for diRNA production at endogenous loci in mammalian cells and give insights into RNA processing at DSBs.
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Affiliation(s)
- Franziska Bonath
- Science for Life Laboratory, Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Judit Domingo-Prim
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Marcel Tarbier
- Science for Life Laboratory, Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Marc R Friedländer
- Science for Life Laboratory, Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Neus Visa
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, SE-106 91 Stockholm, Sweden
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Bhattacharjee S, Roche B, Martienssen RA. RNA-induced initiation of transcriptional silencing (RITS) complex structure and function. RNA Biol 2019; 16:1133-1146. [PMID: 31213126 DOI: 10.1080/15476286.2019.1621624] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Heterochromatic regions of the genome are epigenetically regulated to maintain a heritable '"silent state"'. In fission yeast and other organisms, epigenetic silencing is guided by nascent transcripts, which are targeted by the RNA interference pathway. The key effector complex of the RNA interference pathway consists of small interfering RNA molecules (siRNAs) associated with Argonaute, assembled into the RNA-induced transcriptional silencing (RITS) complex. This review focuses on our current understanding of how RITS promotes heterochromatin formation, and in particular on the role of Argonaute-containing complexes in many other functions such as quelling, release of RNA polymerases, cellular quiescence and genome defense.
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Affiliation(s)
- Sonali Bhattacharjee
- a Cold Spring Harbor Laboratory, Howard Hughes Medical Institute , Cold Spring Harbor , NY , USA
| | - Benjamin Roche
- a Cold Spring Harbor Laboratory, Howard Hughes Medical Institute , Cold Spring Harbor , NY , USA
| | - Robert A Martienssen
- a Cold Spring Harbor Laboratory, Howard Hughes Medical Institute , Cold Spring Harbor , NY , USA
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38
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Abstract
Genome replication involves dealing with obstacles that can result from DNA damage but also from chromatin alterations, topological stress, tightly bound proteins or non-B DNA structures such as R loops. Experimental evidence reveals that an engaged transcription machinery at the DNA can either enhance such obstacles or be an obstacle itself. Thus, transcription can become a potentially hazardous process promoting localized replication fork hindrance and stress, which would ultimately cause genome instability, a hallmark of cancer cells. Understanding the causes behind transcription-replication conflicts as well as how the cell resolves them to sustain genome integrity is the aim of this review.
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39
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Lie S, Banks P, Lawless C, Lydall D, Petersen J. The contribution of non-essential Schizosaccharomyces pombe genes to fitness in response to altered nutrient supply and target of rapamycin activity. Open Biol 2019; 8:rsob.180015. [PMID: 29720420 PMCID: PMC5990653 DOI: 10.1098/rsob.180015] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Accepted: 04/06/2018] [Indexed: 12/12/2022] Open
Abstract
Nutrient fluctuations in the cellular environment promote changes in cell metabolism and growth to adapt cell proliferation accordingly. The target of rapamycin (TOR) signalling network plays a key role in the coordination of growth and cell proliferation with the nutrient environment and, importantly, nutrient limitation reduces TOR complex 1 (TORC1) signalling. We have performed global quantitative fitness profiling of the collection of Schizosaccharomyces pombe strains from which non-essential genes have been deleted. We identified genes that regulate fitness when cells are grown in a nutrient-rich environment compared with minimal environments, with varying nitrogen sources including ammonium, glutamate and proline. In addition, we have performed the first global screen for genes that regulate fitness when both TORC1 and TORC2 signalling is reduced by Torin1. Analysis of genes whose deletions altered fitness when nutrients were limited, or when TOR signalling was compromised, identified a large number of genes that regulate transmembrane transport, transcription and chromatin organization/regulation and vesicle-mediated transport. The ability to tolerate reduced TOR signalling placed demands upon a large number of biological processes including autophagy, mRNA metabolic processing and nucleocytoplasmic transport. Importantly, novel biological processes and all processes known to be regulated by TOR were identified in our screens. In addition, deletion of 62 genes conserved in humans gave rise to strong sensitivity or resistance to Torin1, and 29 of these 62 genes have novel links to TOR signalling. The identification of chromatin and transcriptional regulation, nutritional uptake and transport pathways in this powerful genetic model now paves the way for a molecular understanding of how cells adapt to the chronic and acute fluctuations in nutrient supply that all eukaryotes experience at some stage, and which is a key feature of cancer cells within solid tumours.
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Affiliation(s)
- Shervi Lie
- Flinders Centre for Innovation in Cancer, College of Medicine & Public Health, Flinders University, Bedford Park, Adelaide, South Australia 5042, Australia
| | - Peter Banks
- High Throughput Screening Facility, Newcastle Biomedicine, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Conor Lawless
- Institute for Cell & Molecular Biosciences, Newcastle University Medical School, Newcastle upon Tyne NE2 4HH, UK
| | - David Lydall
- Institute for Cell & Molecular Biosciences, Newcastle University Medical School, Newcastle upon Tyne NE2 4HH, UK
| | - Janni Petersen
- Flinders Centre for Innovation in Cancer, College of Medicine & Public Health, Flinders University, Bedford Park, Adelaide, South Australia 5042, Australia .,South Australia Health and Medical Research Institute, North Terrace, PO Box 11060, Adelaide, South Australia 5000, Australia
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40
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Ghosh D, Venkataramani P, Nandi S, Bhattacharjee S. CRISPR-Cas9 a boon or bane: the bumpy road ahead to cancer therapeutics. Cancer Cell Int 2019; 19:12. [PMID: 30636933 PMCID: PMC6325665 DOI: 10.1186/s12935-019-0726-0] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Accepted: 01/02/2019] [Indexed: 12/13/2022] Open
Abstract
Genome editing allows for the precise manipulation of DNA sequences in a cell making this technology essential for understanding gene function. CRISPR/Cas9 is a targeted genome-editing platform derived from bacterial adaptive immune system and has been repurposed into a genome-editing tool. The RNA-guided DNA endonuclease, Cas9 can be easily programmed to target new sites by altering its guide RNA sequence, making this technology easier, more efficient, scalable and an indispensable tool in biological research. This technology has helped genetically engineer animal models to understand disease mechanisms and elucidate molecular details that can be exploited for improved therapeutic outcomes. In this review, we describe the CRISPR-Cas9 gene-editing mechanism, CRISPR-screening methods, therapeutic targeting of CRISPR in animal models and in cancer immunotherapy. We also discuss the ongoing clinical trials using this tool, limitations of this tool that might impede the clinical applicability of CRISPR-Cas9 and future directions for developing effective CRISPR-Cas9 delivery systems that may improve cancer therapeutics.
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Affiliation(s)
- Debarati Ghosh
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY USA
| | | | - Saikat Nandi
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY USA
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41
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Warmerdam DO, Wolthuis RMF. Keeping ribosomal DNA intact: a repeating challenge. Chromosome Res 2018; 27:57-72. [PMID: 30556094 PMCID: PMC6394564 DOI: 10.1007/s10577-018-9594-z] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Revised: 11/20/2018] [Accepted: 11/29/2018] [Indexed: 02/06/2023]
Abstract
More than half of the human genome consists of repetitive sequences, with the ribosomal DNA (rDNA) representing two of the largest repeats. Repetitive rDNA sequences may form a threat to genomic integrity and cellular homeostasis due to the challenging aspects of their transcription, replication, and repair. Predisposition to cancer, premature aging, and neurological impairment in ataxia-telangiectasia and Bloom syndrome, for instance, coincide with increased cellular rDNA repeat instability. However, the mechanisms by which rDNA instability contributes to these hereditary syndromes and tumorigenesis remain unknown. Here, we review how cells govern rDNA stability and how rDNA break repair influences expansion and contraction of repeat length, a process likely associated with human disease. Recent advancements in CRISPR-based genome engineering may help to explain how cells keep their rDNA intact in the near future.
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Affiliation(s)
- Daniël O Warmerdam
- CRISPR Platform, University of Amsterdam, Cancer Center Amsterdam, Amsterdam UMC, Meibergdreef 9, 1105 AZ, Amsterdam, the Netherlands.
| | - Rob M F Wolthuis
- Section of Oncogenetics, Department of Clinical Genetics, Vrije Universiteit Amsterdam, Cancer Center Amsterdam, Amsterdam UMC, de Boelelaan 1117, 1081 HV, Amsterdam, the Netherlands
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42
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Ghosh D, Nandi S, Bhattacharjee S. Combination therapy to checkmate Glioblastoma: clinical challenges and advances. Clin Transl Med 2018; 7:33. [PMID: 30327965 PMCID: PMC6191404 DOI: 10.1186/s40169-018-0211-8] [Citation(s) in RCA: 136] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Accepted: 10/01/2018] [Indexed: 12/11/2022] Open
Abstract
Combination therapy is increasingly becoming the cornerstone of current day antitumor therapy. Glioblastoma multiforme is an aggressive brain tumor with a dismal median survival post diagnosis and a high rate of disease recurrence. The poor prognosis can be attributed to unique treatment limitations, which include the infiltrative nature of tumor cells, failure of anti-glioma drugs to cross the blood-brain barrier, tumor heterogeneity and the highly metastatic and angiogenic nature of the tumor making cells resistant to chemotherapy. Combination therapy approach is being developed against glioblastoma with new innovative combination drug regimens being tested in preclinical and clinical trials. In this review, we discuss the pathophysiology of glioblastoma, diagnostic markers, therapeutic targeting strategies, current treatment limitations, novel combination therapies in the context of current treatment options and the ongoing clinical trials for glioblastoma therapy.
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Affiliation(s)
- Debarati Ghosh
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA
| | - Saikat Nandi
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA.
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43
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Bhattacharjee S, Nandi S. Rare Genetic Diseases with Defects in DNA Repair: Opportunities and Challenges in Orphan Drug Development for Targeted Cancer Therapy. Cancers (Basel) 2018; 10:E298. [PMID: 30200453 PMCID: PMC6162646 DOI: 10.3390/cancers10090298] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Revised: 08/27/2018] [Accepted: 08/28/2018] [Indexed: 12/22/2022] Open
Abstract
A better understanding of mechanistic insights into genes and enzymes implicated in rare diseases provide a unique opportunity for orphan drug development. Advances made in identification of synthetic lethal relationships between rare disorder genes with oncogenes and tumor suppressor genes have brought in new anticancer therapeutic opportunities. Additionally, the rapid development of small molecule inhibitors against enzymes that participate in DNA damage response and repair has been a successful strategy for targeted cancer therapeutics. Here, we discuss the recent advances in our understanding of how many rare disease genes participate in promoting genome stability. We also summarize the latest developments in exploiting rare diseases to uncover new biological mechanisms and identify new synthetic lethal interactions for anticancer drug discovery that are in various stages of preclinical and clinical studies.
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Affiliation(s)
| | - Saikat Nandi
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, NY 11724, USA.
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44
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Feng L, Shi Z, Xie J, Ma B, Chen X. Enhancer of polycomb maintains germline activity and genome integrity in Drosophila testis. Cell Death Differ 2018; 25:1486-1502. [PMID: 29362481 PMCID: PMC6113212 DOI: 10.1038/s41418-017-0056-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Revised: 11/20/2017] [Accepted: 12/11/2017] [Indexed: 11/09/2022] Open
Abstract
Tissue homeostasis depends on the ability of tissue-specific adult stem cells to maintain a balance between proliferation and differentiation, as well as ensure DNA damage repair. Here, we use the Drosophila male germline stem cell system to study how a chromatin factor, enhancer of polycomb [E(Pc)], regulates the proliferation-to-differentiation (mitosis-to-meiosis) transition and DNA damage repair. We identified two critical targets of E(Pc). First, E(Pc) represses CycB transcription, likely through modulating H4 acetylation. Second, E(Pc) is required for accumulation of an important germline differentiation factor, Bag-of-marbles (Bam), through post-transcriptional regulation. When E(Pc) is downregulated, increased CycB and decreased Bam are both responsible for defective mitosis-to-meiosis transition in the germline. Moreover, DNA double-strand breaks (DSBs) accumulate upon germline inactivation of E(Pc) under both physiological condition and recovery from heat shock-induced endonuclease expression. Failure of robust DSB repair likely leads to germ cell loss. Finally, compromising the activity of Tip60, a histone acetyltransferase, leads to germline defects similar to E(Pc) loss-of-function, suggesting that E(Pc) acts cooperatively with Tip60. Together, our data demonstrate that E(Pc) has pleiotropic roles in maintaining male germline activity and genome integrity. Our findings will help elucidate the in vivo molecular mechanisms of E(Pc).
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Affiliation(s)
- Lijuan Feng
- Department of Biology, The Johns Hopkins University, Baltimore, MD, 21218, USA
- Laboratory of Chromatin Biology and Epigenetics, The Rockefeller University, New York, NY, 10065, USA
| | - Zhen Shi
- Department of Biology, The Johns Hopkins University, Baltimore, MD, 21218, USA
- Geometry Technologies LLC, 6-302, 289 Bisheng Lane, Zhangjiang, Shanghai, 201204, China
| | - Jing Xie
- Department of Biology, The Johns Hopkins University, Baltimore, MD, 21218, USA
- Clinical Research Center for Stem Cell Therapy and Institute for Regenerative Medicine, Shanghai East Hospital; School of Life Sciences and Technology, Tongji University, Shanghai, 200092, China
| | - Binbin Ma
- Department of Biology, The Johns Hopkins University, Baltimore, MD, 21218, USA
- Clinical Research Center for Stem Cell Therapy and Institute for Regenerative Medicine, Shanghai East Hospital; School of Life Sciences and Technology, Tongji University, Shanghai, 200092, China
| | - Xin Chen
- Department of Biology, The Johns Hopkins University, Baltimore, MD, 21218, USA.
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45
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Bhattacharjee S, Nandi S. Synthetic lethality in DNA repair network: A novel avenue in targeted cancer therapy and combination therapeutics. IUBMB Life 2018; 69:929-937. [PMID: 29171189 DOI: 10.1002/iub.1696] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Accepted: 11/05/2017] [Indexed: 11/06/2022]
Abstract
Synthetic lethality refers to a lethal phenotype that results from the simultaneous disruptions of two genes, while the disruption of either gene alone is viable. Many DNA double strand break repair (DSBR) genes have synthetic lethal relationships with oncogenes and tumor suppressor genes, which can be exploited for targeted cancer therapy, an approach referred to as combination therapy. DNA double-strand breaks (DSBs) are one of the most toxic lesions to a cell and can be repaired by non-homologous end joining (NHEJ) or homologous recombination (HR). HR and NHEJ genes are particularly attractive targets for cancer therapy because these genes have altered expression patterns in cancer cells when compared with normal cells and these genetic abnormalities can be targeted for selectively killing cancer cells. Here, we review recent advances in the development of small molecule inhibitors against HR and NHEJ genes to induce synthetic lethality and address the future directions and clinical relevance of this approach. © 2017 IUBMB Life, 69(12):929-937, 2017.
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Affiliation(s)
| | - Saikat Nandi
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA
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46
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Bases of antisense lncRNA-associated regulation of gene expression in fission yeast. PLoS Genet 2018; 14:e1007465. [PMID: 29975684 PMCID: PMC6049938 DOI: 10.1371/journal.pgen.1007465] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Revised: 07/17/2018] [Accepted: 06/01/2018] [Indexed: 12/16/2022] Open
Abstract
Antisense (as)lncRNAs can regulate gene expression but the underlying mechanisms and the different cofactors involved remain unclear. Using Native Elongating Transcript sequencing, here we show that stabilization of antisense Exo2-sensitivite lncRNAs (XUTs) results in the attenuation, at the nascent transcription level, of a subset of highly expressed genes displaying prominent promoter-proximal nucleosome depletion and histone acetylation. Mechanistic investigations on the catalase gene ctt1 revealed that its induction following oxidative stress is impaired in Exo2-deficient cells, correlating with the accumulation of an asXUT. Interestingly, expression of this asXUT was also activated in wild-type cells upon oxidative stress, concomitant to ctt1 induction, indicating a potential attenuation feedback. This attenuation correlates with asXUT abundance, it is transcriptional, characterized by low RNAPII-ser5 phosphorylation, and it requires an histone deacetylase activity and the conserved Set2 histone methyltransferase. Finally, we identified Dicer as another RNA processing factor acting on ctt1 induction, but independently of Exo2. We propose that asXUTs could modulate the expression of their paired-sense genes when it exceeds a critical threshold, using a conserved mechanism independent of RNAi.
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47
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Ebrahimi H, Masuda H, Jain D, Cooper JP. Distinct 'safe zones' at the nuclear envelope ensure robust replication of heterochromatic chromosome regions. eLife 2018; 7:32911. [PMID: 29722648 PMCID: PMC5933923 DOI: 10.7554/elife.32911] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Accepted: 03/30/2018] [Indexed: 12/24/2022] Open
Abstract
Chromosome replication and transcription occur within a complex nuclear milieu whose functional subdomains are beginning to be mapped out. Here we delineate distinct domains of the fission yeast nuclear envelope (NE), focusing on regions enriched for the inner NE protein, Bqt4, or the lamin interacting domain protein, Lem2. Bqt4 is relatively mobile around the NE and acts in two capacities. First, Bqt4 tethers chromosome termini and the mat locus to the NE specifically while these regions are replicating. This positioning is required for accurate heterochromatin replication. Second, Bqt4 mobilizes a subset of Lem2 molecules around the NE to promote pericentric heterochromatin maintenance. Opposing Bqt4-dependent Lem2 mobility are factors that stabilize Lem2 beneath the centrosome, where Lem2 plays a crucial role in kinetochore maintenance. Our data prompt a model in which Bqt4-rich nuclear subdomains are 'safe zones' in which collisions between transcription and replication are averted and heterochromatin is reassembled faithfully.
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Affiliation(s)
- Hani Ebrahimi
- Telomere Biology Section, Laboratory of Biochemistry and Molecular Biology, Center for Cancer Research, National Cancer Institute, Bethesda, United States
| | - Hirohisa Masuda
- Telomere Biology Section, Laboratory of Biochemistry and Molecular Biology, Center for Cancer Research, National Cancer Institute, Bethesda, United States
| | - Devanshi Jain
- Telomere Biology Section, Laboratory of Biochemistry and Molecular Biology, Center for Cancer Research, National Cancer Institute, Bethesda, United States
| | - Julia Promisel Cooper
- Telomere Biology Section, Laboratory of Biochemistry and Molecular Biology, Center for Cancer Research, National Cancer Institute, Bethesda, United States
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48
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Kotsantis P, Petermann E, Boulton SJ. Mechanisms of Oncogene-Induced Replication Stress: Jigsaw Falling into Place. Cancer Discov 2018; 8:537-555. [PMID: 29653955 DOI: 10.1158/2159-8290.cd-17-1461] [Citation(s) in RCA: 232] [Impact Index Per Article: 38.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Revised: 02/26/2018] [Accepted: 03/09/2018] [Indexed: 12/31/2022]
Abstract
Oncogene activation disturbs cellular processes and accommodates a complex landscape of changes in the genome that contribute to genomic instability, which accelerates mutation rates and promotes tumorigenesis. Part of this cellular turmoil involves deregulation of physiologic DNA replication, widely described as replication stress. Oncogene-induced replication stress is an early driver of genomic instability and is attributed to a plethora of factors, most notably aberrant origin firing, replication-transcription collisions, reactive oxygen species, and defective nucleotide metabolism.Significance: Replication stress is a fundamental step and an early driver of tumorigenesis and has been associated with many activated oncogenes. Deciphering the mechanisms that contribute to the replication stress response may provide new avenues for targeted cancer treatment. In this review, we discuss the latest findings on the DNA replication stress response and examine the various mechanisms through which activated oncogenes induce replication stress. Cancer Discov; 8(5); 537-55. ©2018 AACR.
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Affiliation(s)
| | - Eva Petermann
- Institute of Cancer and Genomic Sciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom
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49
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Begnis M, Apte MS, Masuda H, Jain D, Wheeler DL, Cooper JP. RNAi drives nonreciprocal translocations at eroding chromosome ends to establish telomere-free linear chromosomes. Genes Dev 2018; 32:537-554. [PMID: 29654060 PMCID: PMC5959237 DOI: 10.1101/gad.311712.118] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Accepted: 03/29/2018] [Indexed: 12/19/2022]
Abstract
In this study, Begnis et al. show that HAATI, which is a mode of telomerase-minus survival in which canonical telomeres are superseded by blocks of nontelomeric rDNA heterochromatin that have spread to all chromosome ends, is formed and maintained. Their findings demonstrate that HAATI arises when telomere loss triggers a newly recognized illegitimate recombination pathway that requires RNAi factors, uncovering novel roles for ncRNAs in assembling a telomere-free chromosome end protection device. The identification of telomerase-negative HAATI (heterochromatin amplification-mediated and telomerase-independent) cells, in which telomeres are superseded by nontelomeric heterochromatin tracts, challenged the idea that canonical telomeres are essential for chromosome linearity and raised crucial questions as to how such tracts translocate to eroding chromosome ends and confer end protection. Here we show that HAATI arises when telomere loss triggers a newly recognized illegitimate translocation pathway that requires RNAi factors. While RNAi is necessary for the translocation events that mobilize ribosomal DNA (rDNA) tracts to all chromosome ends (forming “HAATIrDNA” chromosomes), it is dispensable for HAATIrDNA maintenance. Surprisingly, Dicer (Dcr1) plays a separate, RNAi-independent role in preventing formation of the rare HAATI subtype in which a different repetitive element (the subtelomeric element) replaces telomeres. Using genetics and fusions between shelterin components and rDNA-binding proteins, we mapped the mechanism by which rDNA loci engage crucial end protection factors—despite the absence of telomere repeats—and secure end protection. Sequence analysis of HAATIrDNA genomes allowed us to propose RNA and DNA polymerase template-switching models for the mechanism of RNAi-triggered rDNA translocations. Collectively, our results reveal unforeseen roles for noncoding RNAs (ncRNAs) in assembling a telomere-free chromosome end protection device.
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Affiliation(s)
- Martina Begnis
- Telomere Biology Section, Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA.,Telomere Biology Laboratory, Cancer Research UK, London Research Institute, London WC2A 3LY, United Kingdom
| | - Manasi S Apte
- Telomere Biology Section, Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Hirohisa Masuda
- Telomere Biology Section, Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Devanshi Jain
- Molecular Biology Program, Memorial Sloan Kettering Cancer Center, New York, New York 10065, USA
| | - David Lee Wheeler
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Julia Promisel Cooper
- Telomere Biology Section, Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA.,Telomere Biology Laboratory, Cancer Research UK, London Research Institute, London WC2A 3LY, United Kingdom
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50
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Michelini F, Jalihal AP, Francia S, Meers C, Neeb ZT, Rossiello F, Gioia U, Aguado J, Jones-Weinert C, Luke B, Biamonti G, Nowacki M, Storici F, Carninci P, Walter NG, d'Adda di Fagagna F. From "Cellular" RNA to "Smart" RNA: Multiple Roles of RNA in Genome Stability and Beyond. Chem Rev 2018; 118:4365-4403. [PMID: 29600857 DOI: 10.1021/acs.chemrev.7b00487] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Coding for proteins has been considered the main function of RNA since the "central dogma" of biology was proposed. The discovery of noncoding transcripts shed light on additional roles of RNA, ranging from the support of polypeptide synthesis, to the assembly of subnuclear structures, to gene expression modulation. Cellular RNA has therefore been recognized as a central player in often unanticipated biological processes, including genomic stability. This ever-expanding list of functions inspired us to think of RNA as a "smart" phone, which has replaced the older obsolete "cellular" phone. In this review, we summarize the last two decades of advances in research on the interface between RNA biology and genome stability. We start with an account of the emergence of noncoding RNA, and then we discuss the involvement of RNA in DNA damage signaling and repair, telomere maintenance, and genomic rearrangements. We continue with the depiction of single-molecule RNA detection techniques, and we conclude by illustrating the possibilities of RNA modulation in hopes of creating or improving new therapies. The widespread biological functions of RNA have made this molecule a reoccurring theme in basic and translational research, warranting it the transcendence from classically studied "cellular" RNA to "smart" RNA.
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Affiliation(s)
- Flavia Michelini
- IFOM - The FIRC Institute of Molecular Oncology , Milan , 20139 , Italy
| | - Ameya P Jalihal
- Single Molecule Analysis Group and Center for RNA Biomedicine, Department of Chemistry , University of Michigan , Ann Arbor , Michigan 48109-1055 , United States
| | - Sofia Francia
- IFOM - The FIRC Institute of Molecular Oncology , Milan , 20139 , Italy.,Istituto di Genetica Molecolare , CNR - Consiglio Nazionale delle Ricerche , Pavia , 27100 , Italy
| | - Chance Meers
- School of Biological Sciences , Georgia Institute of Technology , Atlanta , Georgia 30332 , United States
| | - Zachary T Neeb
- Institute of Cell Biology , University of Bern , Baltzerstrasse 4 , 3012 Bern , Switzerland
| | | | - Ubaldo Gioia
- IFOM - The FIRC Institute of Molecular Oncology , Milan , 20139 , Italy
| | - Julio Aguado
- IFOM - The FIRC Institute of Molecular Oncology , Milan , 20139 , Italy
| | | | - Brian Luke
- Institute of Developmental Biology and Neurobiology , Johannes Gutenberg University , 55099 Mainz , Germany.,Institute of Molecular Biology (IMB) , 55128 Mainz , Germany
| | - Giuseppe Biamonti
- Istituto di Genetica Molecolare , CNR - Consiglio Nazionale delle Ricerche , Pavia , 27100 , Italy
| | - Mariusz Nowacki
- Institute of Cell Biology , University of Bern , Baltzerstrasse 4 , 3012 Bern , Switzerland
| | - Francesca Storici
- School of Biological Sciences , Georgia Institute of Technology , Atlanta , Georgia 30332 , United States
| | - Piero Carninci
- RIKEN Center for Life Science Technologies , 1-7-22 Suehiro-cho, Tsurumi-ku , Yokohama City , Kanagawa 230-0045 , Japan
| | - Nils G Walter
- Single Molecule Analysis Group and Center for RNA Biomedicine, Department of Chemistry , University of Michigan , Ann Arbor , Michigan 48109-1055 , United States
| | - Fabrizio d'Adda di Fagagna
- IFOM - The FIRC Institute of Molecular Oncology , Milan , 20139 , Italy.,Istituto di Genetica Molecolare , CNR - Consiglio Nazionale delle Ricerche , Pavia , 27100 , Italy
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