1
|
Trifault B, Mamontova V, Cossa G, Ganskih S, Wei Y, Hofstetter J, Bhandare P, Baluapuri A, Nieto B, Solvie D, Ade CP, Gallant P, Wolf E, Larsen DH, Munschauer M, Burger K. Nucleolar detention of NONO shields DNA double-strand breaks from aberrant transcripts. Nucleic Acids Res 2024; 52:3050-3068. [PMID: 38224452 PMCID: PMC11014278 DOI: 10.1093/nar/gkae022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Revised: 12/11/2023] [Accepted: 01/04/2024] [Indexed: 01/16/2024] Open
Abstract
RNA-binding proteins emerge as effectors of the DNA damage response (DDR). The multifunctional non-POU domain-containing octamer-binding protein NONO/p54nrb marks nuclear paraspeckles in unperturbed cells, but also undergoes re-localization to the nucleolus upon induction of DNA double-strand breaks (DSBs). However, NONO nucleolar re-localization is poorly understood. Here we show that the topoisomerase II inhibitor etoposide stimulates the production of RNA polymerase II-dependent, DNA damage-inducible antisense intergenic non-coding RNA (asincRNA) in human cancer cells. Such transcripts originate from distinct nucleolar intergenic spacer regions and form DNA-RNA hybrids to tether NONO to the nucleolus in an RNA recognition motif 1 domain-dependent manner. NONO occupancy at protein-coding gene promoters is reduced by etoposide, which attenuates pre-mRNA synthesis, enhances NONO binding to pre-mRNA transcripts and is accompanied by nucleolar detention of a subset of such transcripts. The depletion or mutation of NONO interferes with detention and prolongs DSB signalling. Together, we describe a nucleolar DDR pathway that shields NONO and aberrant transcripts from DSBs to promote DNA repair.
Collapse
Affiliation(s)
- Barbara Trifault
- Mildred Scheel Early Career Center for Cancer Research (Mildred-Scheel-Nachwuchszentrum, MSNZ) Würzburg, University Hospital Würzburg, Josef-Schneider-Strasse 2, D-97080 Würzburg, Germany
- Department of Biochemistry and Molecular Biology, Biocenter of the University of Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Victoria Mamontova
- Mildred Scheel Early Career Center for Cancer Research (Mildred-Scheel-Nachwuchszentrum, MSNZ) Würzburg, University Hospital Würzburg, Josef-Schneider-Strasse 2, D-97080 Würzburg, Germany
- Department of Biochemistry and Molecular Biology, Biocenter of the University of Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Giacomo Cossa
- Department of Biochemistry and Molecular Biology, Biocenter of the University of Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Sabina Ganskih
- Helmholtz Institute for RNA-based Infection Research, Helmholtz-Center for Infection Research, Josef-Schneider-Strasse 2, D-97080 Würzburg, Germany
| | - Yuanjie Wei
- Helmholtz Institute for RNA-based Infection Research, Helmholtz-Center for Infection Research, Josef-Schneider-Strasse 2, D-97080 Würzburg, Germany
| | - Julia Hofstetter
- Cancer Systems Biology Group, Theodor Boveri Institute, Biocenter, University of Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Pranjali Bhandare
- Cancer Systems Biology Group, Theodor Boveri Institute, Biocenter, University of Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Apoorva Baluapuri
- Cancer Systems Biology Group, Theodor Boveri Institute, Biocenter, University of Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Blanca Nieto
- Nucleolar Stress and Disease Group, Danish Cancer Institute, Strandboulevarden 49, Copenhagen, Denmark
| | - Daniel Solvie
- Department of Biochemistry and Molecular Biology, Biocenter of the University of Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Carsten P Ade
- Department of Biochemistry and Molecular Biology, Biocenter of the University of Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Peter Gallant
- Department of Biochemistry and Molecular Biology, Biocenter of the University of Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Elmar Wolf
- Cancer Systems Biology Group, Theodor Boveri Institute, Biocenter, University of Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Dorthe H Larsen
- Nucleolar Stress and Disease Group, Danish Cancer Institute, Strandboulevarden 49, Copenhagen, Denmark
| | - Mathias Munschauer
- Helmholtz Institute for RNA-based Infection Research, Helmholtz-Center for Infection Research, Josef-Schneider-Strasse 2, D-97080 Würzburg, Germany
| | - Kaspar Burger
- Mildred Scheel Early Career Center for Cancer Research (Mildred-Scheel-Nachwuchszentrum, MSNZ) Würzburg, University Hospital Würzburg, Josef-Schneider-Strasse 2, D-97080 Würzburg, Germany
- Department of Biochemistry and Molecular Biology, Biocenter of the University of Würzburg, Am Hubland, D-97074 Würzburg, Germany
| |
Collapse
|
2
|
Arnold MR, Cohn GM, Oxe KC, Elliott SN, Moore C, Laraia PV, Shekoohi S, Brownell D, Meshul CK, Witt SN, Larsen DH, Unni VK. Alpha-synuclein regulates nucleolar DNA double-strand break repair in melanoma. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.13.575526. [PMID: 38260370 PMCID: PMC10802588 DOI: 10.1101/2024.01.13.575526] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
Although an increased risk of the skin cancer melanoma in people with Parkinson's Disease (PD) has been shown in multiple studies, the mechanisms involved are poorly understood, but increased expression of the PD-associated protein alpha-synuclein (αSyn) in melanoma cells may be important. Our previous work suggests that αSyn can facilitate DNA double-strand break (DSB) repair, promoting genomic stability. We now show that αSyn is preferentially enriched within the nucleolus in the SK-MEL28 melanoma cell line, where it colocalizes with DNA damage markers and DSBs. Inducing DSBs specifically within nucleolar ribosomal DNA (rDNA) increases αSyn levels near sites of damage. αSyn knockout increases DNA damage within the nucleolus at baseline, after specific rDNA DSB induction, and prolongs the rate of recovery from this induced damage. αSyn is important downstream of ATM signaling to facilitate 53BP1 recruitment to DSBs, reducing micronuclei formation and promoting cellular proliferation, migration, and invasion.
Collapse
Affiliation(s)
- Moriah R. Arnold
- Medical Scientist Training Program, Oregon Health and Science University, Portland, OR, USA
- Department of Neurology and Jungers Center for Neurosciences Research, Oregon Health and Science University, Portland, OR, USA
| | - Gabriel M. Cohn
- Department of Molecular and Medical Genetics, School of Medicine, Oregon Health and Science University, Portland, OR, USA
| | - Kezia Catharina Oxe
- Danish Cancer Institute, Nucleolar Stress and Disease Group, Strandboulevarden 49, 2100 Copenhagen, Denmark
| | - Somarr N. Elliott
- Department of Neurology and Jungers Center for Neurosciences Research, Oregon Health and Science University, Portland, OR, USA
| | - Cynthia Moore
- Research Services, Neurocytology Laboratory, Veterans Affairs Medical Center, Portland, OR, USA
| | | | - Sahar Shekoohi
- Department of Biochemistry and Molecular Biology, Louisiana State University Health Sciences Center, Shreveport, LA, USA
| | - Dillon Brownell
- Department of Molecular Microbiology and Immunology, Oregon Health and Science University, Portland, OR, USA
| | - Charles K. Meshul
- Research Services, Neurocytology Laboratory, Veterans Affairs Medical Center, Portland, OR, USA
- Departments of Behavioral Neuroscience and Pathology, Oregon Health and Science University, Portland, OR, USA
| | - Stephan N. Witt
- Department of Biochemistry and Molecular Biology, Louisiana State University Health Sciences Center, Shreveport, LA, USA
| | - Dorthe H. Larsen
- Danish Cancer Institute, Nucleolar Stress and Disease Group, Strandboulevarden 49, 2100 Copenhagen, Denmark
| | - Vivek K. Unni
- Department of Neurology and Jungers Center for Neurosciences Research, Oregon Health and Science University, Portland, OR, USA
- OHSU Parkinson’s Center, Oregon Health and Science University, Portland, OR, USA
| |
Collapse
|
3
|
Mei J, Böhland C, Geiger A, Baur I, Berner K, Heuer S, Liu X, Mataite L, Melo-Narváez MC, Özkaya E, Rupp A, Siebenwirth C, Thoma F, Kling MF, Friedl AA. Development of a model for fibroblast-led collective migration from breast cancer cell spheroids to study radiation effects on invasiveness. Radiat Oncol 2021; 16:159. [PMID: 34412654 PMCID: PMC8375131 DOI: 10.1186/s13014-021-01883-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Accepted: 08/12/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Invasiveness is a major factor contributing to metastasis of tumour cells. Given the broad variety and plasticity of invasion mechanisms, assessing potential metastasis-promoting effects of irradiation for specific mechanisms is important for further understanding of potential adverse effects of radiotherapy. In fibroblast-led invasion mechanisms, fibroblasts produce tracks in the extracellular matrix in which cancer cells with epithelial traits can follow. So far, the influence of irradiation on this type of invasion mechanisms has not been assessed. METHODS By matrix-embedding coculture spheroids consisting of breast cancer cells (MCF-7, BT474) and normal fibroblasts, we established a model for fibroblast-led invasion. To demonstrate applicability of this model, spheroid growth and invasion behaviour after irradiation with 5 Gy were investigated by microscopy and image analysis. RESULTS When not embedded, irradiation caused a significant growth delay in the spheroids. When irradiating the spheroids with 5 Gy before embedding, we find comparable maximum migration distance in fibroblast monoculture and in coculture samples as seen in unirradiated samples. Depending on the fibroblast strain, the number of invading cells remained constant or was reduced. CONCLUSION In this spheroid model and with the cell lines and fibroblast strains used, irradiation does not have a major invasion-promoting effect. 3D analysis of invasiveness allows to uncouple effects on invading cell number and maximum invasion distance when assessing radiation effects.
Collapse
Affiliation(s)
- Jia Mei
- Department of Radiation Oncology, LMU Klinikum, LMU Munich, 81377, Munich, Germany.,Department of Physics, LMU Munich, 85748, Garching, Germany
| | - Claudia Böhland
- Department of Radiation Oncology, LMU Klinikum, LMU Munich, 81377, Munich, Germany
| | - Anika Geiger
- Department of Radiation Oncology, LMU Klinikum, LMU Munich, 81377, Munich, Germany
| | - Iris Baur
- Department of Radiation Oncology, LMU Klinikum, LMU Munich, 81377, Munich, Germany
| | - Kristina Berner
- Department of Radiation Oncology, LMU Klinikum, LMU Munich, 81377, Munich, Germany
| | - Steffen Heuer
- Research Unit of Radiation Cytogenetics, Helmholtz Zentrum München, 85764, Neuherberg, Germany.,Clinical Cooperation Group 'Personalized Radiotherapy in Head and Neck Cancer', Helmholtz Zentrum München, 85764, Neuherberg, Germany
| | - Xue Liu
- RG Adipocytes & Metabolism, Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, 85764, Neuherberg, Germany.,German Center for Diabetes Research (DZD), 85764, Neuherberg, Germany
| | - Laura Mataite
- Department of Radiation Oncology, LMU Klinikum, LMU Munich, 81377, Munich, Germany
| | | | - Erdem Özkaya
- Department of Radiation Oncology, LMU Klinikum, LMU Munich, 81377, Munich, Germany
| | - Anna Rupp
- Department of Radiation Oncology, LMU Klinikum, LMU Munich, 81377, Munich, Germany
| | | | - Felix Thoma
- Department of Radiation Oncology, LMU Klinikum, LMU Munich, 81377, Munich, Germany
| | - Matthias F Kling
- Department of Physics, LMU Munich, 85748, Garching, Germany.,Center for Advanced Laser Applications, 85748, Garching, Germany
| | - Anna A Friedl
- Department of Radiation Oncology, LMU Klinikum, LMU Munich, 81377, Munich, Germany.
| |
Collapse
|
4
|
Xuan J, Gitareja K, Brajanovski N, Sanij E. Harnessing the Nucleolar DNA Damage Response in Cancer Therapy. Genes (Basel) 2021; 12:genes12081156. [PMID: 34440328 PMCID: PMC8393943 DOI: 10.3390/genes12081156] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Revised: 07/20/2021] [Accepted: 07/26/2021] [Indexed: 12/19/2022] Open
Abstract
The nucleoli are subdomains of the nucleus that form around actively transcribed ribosomal RNA (rRNA) genes. They serve as the site of rRNA synthesis and processing, and ribosome assembly. There are 400-600 copies of rRNA genes (rDNA) in human cells and their highly repetitive and transcribed nature poses a challenge for DNA repair and replication machineries. It is only in the last 7 years that the DNA damage response and processes of DNA repair at the rDNA repeats have been recognized to be unique and distinct from the classic response to DNA damage in the nucleoplasm. In the last decade, the nucleolus has also emerged as a central hub for coordinating responses to stress via sequestering tumor suppressors, DNA repair and cell cycle factors until they are required for their functional role in the nucleoplasm. In this review, we focus on features of the rDNA repeats that make them highly vulnerable to DNA damage and the mechanisms by which rDNA damage is repaired. We highlight the molecular consequences of rDNA damage including activation of the nucleolar DNA damage response, which is emerging as a unique response that can be exploited in anti-cancer therapy. In this review, we focus on CX-5461, a novel inhibitor of Pol I transcription that induces the nucleolar DNA damage response and is showing increasing promise in clinical investigations.
Collapse
Affiliation(s)
- Jiachen Xuan
- Peter MacCallum Cancer Centre, Melbourne, VIC 3000, Australia; (J.X.); (K.G.); (N.B.)
- Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Kezia Gitareja
- Peter MacCallum Cancer Centre, Melbourne, VIC 3000, Australia; (J.X.); (K.G.); (N.B.)
| | - Natalie Brajanovski
- Peter MacCallum Cancer Centre, Melbourne, VIC 3000, Australia; (J.X.); (K.G.); (N.B.)
| | - Elaine Sanij
- Peter MacCallum Cancer Centre, Melbourne, VIC 3000, Australia; (J.X.); (K.G.); (N.B.)
- Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, VIC 3010, Australia
- Department of Clinical Pathology, University of Melbourne, Melbourne, VIC 3010, Australia
- St Vincent’s Institute of Medical Research, Fitzroy, VIC 3065, Australia
- Department of Medicine -St Vincent’s Hospital, University of Melbourne, Melbourne, VIC 3010, Australia
- Correspondence: ; Tel.: +61-3-8559-5279
| |
Collapse
|
5
|
Lorat Y, Reindl J, Isermann A, Rübe C, Friedl AA, Rübe CE. Focused Ion Microbeam Irradiation Induces Clustering of DNA Double-Strand Breaks in Heterochromatin Visualized by Nanoscale-Resolution Electron Microscopy. Int J Mol Sci 2021; 22:ijms22147638. [PMID: 34299263 PMCID: PMC8306362 DOI: 10.3390/ijms22147638] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Revised: 07/06/2021] [Accepted: 07/15/2021] [Indexed: 12/14/2022] Open
Abstract
Background: Charged-particle radiotherapy is an emerging treatment modality for radioresistant tumors. The enhanced effectiveness of high-energy particles (such as heavy ions) has been related to the spatial clustering of DNA lesions due to highly localized energy deposition. Here, DNA damage patterns induced by single and multiple carbon ions were analyzed in the nuclear chromatin environment by different high-resolution microscopy approaches. Material and Methods: Using the heavy-ion microbeam SNAKE, fibroblast monolayers were irradiated with defined numbers of carbon ions (1/10/100 ions per pulse, ipp) focused to micrometer-sized stripes or spots. Radiation-induced lesions were visualized as DNA damage foci (γH2AX, 53BP1) by conventional fluorescence and stimulated emission depletion (STED) microscopy. At micro- and nanoscale level, DNA double-strand breaks (DSBs) were visualized within their chromatin context by labeling the Ku heterodimer. Single and clustered pKu70-labeled DSBs were quantified in euchromatic and heterochromatic regions at 0.1 h, 5 h and 24 h post-IR by transmission electron microscopy (TEM). Results: Increasing numbers of carbon ions per beam spot enhanced spatial clustering of DNA lesions and increased damage complexity with two or more DSBs in close proximity. This effect was detectable in euchromatin, but was much more pronounced in heterochromatin. Analyzing the dynamics of damage processing, our findings indicate that euchromatic DSBs were processed efficiently and repaired in a timely manner. In heterochromatin, by contrast, the number of clustered DSBs continuously increased further over the first hours following IR exposure, indicating the challenging task for the cell to process highly clustered DSBs appropriately. Conclusion: Increasing numbers of carbon ions applied to sub-nuclear chromatin regions enhanced the spatial clustering of DSBs and increased damage complexity, this being more pronounced in heterochromatic regions. Inefficient processing of clustered DSBs may explain the enhanced therapeutic efficacy of particle-based radiotherapy in cancer treatment.
Collapse
Affiliation(s)
- Yvonne Lorat
- Department of Radiation Oncology, Saarland University Hospital, 66421 Homburg, Germany; (Y.L.); (A.I.); (C.R.)
| | - Judith Reindl
- Institute for Applied Physic and Metrology, Universität der Bundeswehr München, 85577 Neubiberg, Germany;
| | - Anna Isermann
- Department of Radiation Oncology, Saarland University Hospital, 66421 Homburg, Germany; (Y.L.); (A.I.); (C.R.)
| | - Christian Rübe
- Department of Radiation Oncology, Saarland University Hospital, 66421 Homburg, Germany; (Y.L.); (A.I.); (C.R.)
| | - Anna A. Friedl
- Department of Radiation Oncology, University Hospital, Ludwig-Maximilian University, 80539 Munich, Germany;
| | - Claudia E. Rübe
- Department of Radiation Oncology, Saarland University Hospital, 66421 Homburg, Germany; (Y.L.); (A.I.); (C.R.)
- Correspondence: ; Tel.: +49-6841-1634614
| |
Collapse
|
6
|
Rudigkeit S, Reindl JB, Matejka N, Ramson R, Sammer M, Dollinger G, Reindl J. CeCILE - An Artificial Intelligence Based Cell-Detection for the Evaluation of Radiation Effects in Eucaryotic Cells. Front Oncol 2021; 11:688333. [PMID: 34277433 PMCID: PMC8278143 DOI: 10.3389/fonc.2021.688333] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Accepted: 05/31/2021] [Indexed: 12/03/2022] Open
Abstract
The fundamental basis in the development of novel radiotherapy methods is in-vitro cellular studies. To assess different endpoints of cellular reactions to irradiation like proliferation, cell cycle arrest, and cell death, several assays are used in radiobiological research as standard methods. For example, colony forming assay investigates cell survival and Caspase3/7-Sytox assay cell death. The major limitation of these assays is the analysis at a fixed timepoint after irradiation. Thus, not much is known about the reactions before or after the assay is performed. Additionally, these assays need special treatments, which influence cell behavior and health. In this study, a completely new method is proposed to tackle these challenges: A deep-learning algorithm called CeCILE (Cell Classification and In-vitro Lifecycle Evaluation), which is used to detect and analyze cells on videos obtained from phase-contrast microscopy. With this method, we can observe and analyze the behavior and the health conditions of single cells over several days after treatment, up to a sample size of 100 cells per image frame. To train CeCILE, we built a dataset by labeling cells on microscopic images and assign class labels to each cell, which define the cell states in the cell cycle. After successful training of CeCILE, we irradiated CHO-K1 cells with 4 Gy protons, imaged them for 2 days by a microscope equipped with a live-cell-imaging set-up, and analyzed the videos by CeCILE and by hand. From analysis, we gained information about cell numbers, cell divisions, and cell deaths over time. We could show that similar results were achieved in the first proof of principle compared with colony forming and Caspase3/7-Sytox assays in this experiment. Therefore, CeCILE has the potential to assess the same endpoints as state-of-the-art assays but gives extra information about the evolution of cell numbers, cell state, and cell cycle. Additionally, CeCILE will be extended to track individual cells and their descendants throughout the whole video to follow the behavior of each cell and the progeny after irradiation. This tracking method is capable to put radiobiologic research to the next level to obtain a better understanding of the cellular reactions to radiation.
Collapse
Affiliation(s)
- Sarah Rudigkeit
- Institut für Angewandte Physik und Messtechnik, Universität der Bundeswehr München, Neubiberg, Germany
| | | | | | | | | | | | | |
Collapse
|
7
|
|
8
|
Dong C, An L, Yu CH, Huen MSY. A DYRK1B-dependent pathway suppresses rDNA transcription in response to DNA damage. Nucleic Acids Res 2021; 49:1485-1496. [PMID: 33469661 PMCID: PMC7897492 DOI: 10.1093/nar/gkaa1290] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 12/22/2020] [Accepted: 01/18/2021] [Indexed: 12/29/2022] Open
Abstract
DNA double-strand breaks (DSBs) at ribosomal gene loci trigger inhibition of ribosomal DNA (rDNA) transcription and extensive nucleolar reorganization, including the formation of nucleolar caps where rDNA DSBs engage with canonical DSB signaling and repair factors. While these nucleolar responses underlie maintenance of rDNA stability, the molecular components that drive each of these events remain to be defined. Here we report that full suppression of rRNA synthesis requires the DYRK1B kinase, a nucleolar DSB response that can be uncoupled from ATM-mediated DSB signaling events at the nucleolar periphery. Indeed, by targeting DSBs onto rDNA arrays, we uncovered that chemical inhibition or genetic inactivation of DYRK1B led to sustained nucleolar transcription. Not only does DYRK1B exhibit robust nucleolar accumulation following laser micro-irradiation across cell nuclei, we further showed that DYRK1B is required for rDNA DSB repair and rDNA copy number maintenance, and that DYRK1B-inactivated cells are hypersensitised to DSBs induced at the rDNA arrays. Together, our findings not only identify DYRK1B as a key signaling intermediate that coordinates DSB repair and rDNA transcriptional activities, but also support the idea of specialised DSB responses that operate within the nucleolus to preserve rDNA integrity.
Collapse
Affiliation(s)
- Chao Dong
- School of Biomedical Sciences, LKS Faculty of Medicine, The University of Hong Kong, 21 Sassoon Road, Pokfulam, Hong Kong S.A.R
| | - Liwei An
- School of Biomedical Sciences, LKS Faculty of Medicine, The University of Hong Kong, 21 Sassoon Road, Pokfulam, Hong Kong S.A.R
| | - Cheng-han Yu
- School of Biomedical Sciences, LKS Faculty of Medicine, The University of Hong Kong, 21 Sassoon Road, Pokfulam, Hong Kong S.A.R
| | - Michael S Y Huen
- School of Biomedical Sciences, LKS Faculty of Medicine, The University of Hong Kong, 21 Sassoon Road, Pokfulam, Hong Kong S.A.R
- State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, 5 Sassoon Road, Pokfulam, Hong Kong S.A.R
| |
Collapse
|
9
|
Korsholm LM, Gál Z, Nieto B, Quevedo O, Boukoura S, Lund CC, Larsen DH. Recent advances in the nucleolar responses to DNA double-strand breaks. Nucleic Acids Res 2020; 48:9449-9461. [PMID: 32857853 PMCID: PMC7515731 DOI: 10.1093/nar/gkaa713] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Revised: 08/13/2020] [Accepted: 08/26/2020] [Indexed: 12/15/2022] Open
Abstract
DNA damage poses a serious threat to human health and cells therefore continuously monitor and repair DNA lesions across the genome. Ribosomal DNA is a genomic domain that represents a particular challenge due to repetitive sequences, high transcriptional activity and its localization in the nucleolus, where the accessibility of DNA repair factors is limited. Recent discoveries have significantly extended our understanding of how cells respond to DNA double-strand breaks (DSBs) in the nucleolus, and new kinases and multiple down-stream targets have been identified. Restructuring of the nucleolus can occur as a consequence of DSBs and new data point to an active regulation of this process, challenging previous views. Furthermore, new insights into coordination of cell cycle phases and ribosomal DNA repair argue against existing concepts. In addition, the importance of nucleolar-DNA damage response (n-DDR) mechanisms for maintenance of genome stability and the potential of such factors as anti-cancer targets is becoming apparent. This review will provide a detailed discussion of recent findings and their implications for our understanding of the n-DDR. The n-DDR shares features with the DNA damage response (DDR) elsewhere in the genome but is also emerging as an independent response unique to ribosomal DNA and the nucleolus.
Collapse
Affiliation(s)
| | | | - Blanca Nieto
- Danish Cancer Society Research Center, Nucleolar Stress and Disease Group, Strandboulevarden 49, 2100 Copenhagen, Denmark
| | - Oliver Quevedo
- Danish Cancer Society Research Center, Nucleolar Stress and Disease Group, Strandboulevarden 49, 2100 Copenhagen, Denmark
| | - Stavroula Boukoura
- Danish Cancer Society Research Center, Nucleolar Stress and Disease Group, Strandboulevarden 49, 2100 Copenhagen, Denmark
| | - Casper Carstens Lund
- Danish Cancer Society Research Center, Nucleolar Stress and Disease Group, Strandboulevarden 49, 2100 Copenhagen, Denmark
| | | |
Collapse
|