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Simpson D, Ling J, Jing Y, Adamson B. Mapping the Genetic Interaction Network of PARP inhibitor Response. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.19.553986. [PMID: 37645833 PMCID: PMC10462155 DOI: 10.1101/2023.08.19.553986] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Abstract
Genetic interactions have long informed our understanding of the coordinated proteins and pathways that respond to DNA damage in mammalian cells, but systematic interrogation of the genetic network underlying that system has yet to be achieved. Towards this goal, we measured 147,153 pairwise interactions among genes implicated in PARP inhibitor (PARPi) response. Evaluating genetic interactions at this scale, with and without exposure to PARPi, revealed hierarchical organization of the pathways and complexes that maintain genome stability during normal growth and defined changes that occur upon accumulation of DNA lesions due to cytotoxic doses of PARPi. We uncovered unexpected relationships among DNA repair genes, including context-specific buffering interactions between the minimally characterized AUNIP and BRCA1-A complex genes. Our work thus establishes a foundation for mapping differential genetic interactions in mammalian cells and provides a comprehensive resource for future studies of DNA repair and PARP inhibitors.
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Affiliation(s)
- Danny Simpson
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA
| | - Jia Ling
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA
| | - Yangwode Jing
- Department of Chemistry, Princeton University, Princeton, NJ 08544, USA
| | - Britt Adamson
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
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2
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Stillger MN, Chen CY, Lai ZW, Li M, Schäfer A, Pagenstecher A, Nimsky C, Bartsch JW, Schilling O. Changes in calpain-2 expression during glioblastoma progression predisposes tumor cells to temozolomide resistance by minimizing DNA damage and p53-dependent apoptosis. Cancer Cell Int 2023; 23:49. [PMID: 36932402 PMCID: PMC10022304 DOI: 10.1186/s12935-023-02889-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Accepted: 03/04/2023] [Indexed: 03/19/2023] Open
Abstract
BACKGROUND Glioblastoma multiforme (GBM) is characterized by an unfavorable prognosis for patients affected. During standard-of-care chemotherapy using temozolomide (TMZ), tumors acquire resistance thereby causing tumor recurrence. Thus, deciphering essential molecular pathways causing TMZ resistance are of high therapeutic relevance. METHODS Mass spectrometry based proteomics were used to study the GBM proteome. Immunohistochemistry staining of human GBM tissue for either calpain-1 or -2 was performed to locate expression of proteases. In vitro cell based assays were used to measure cell viability and survival of primary patient-derived GBM cells and established GBM cell lines after TMZ ± calpain inhibitor administration. shRNA expression knockdowns of either calpain-1 or calpain-2 were generated to study TMZ sensitivity of the specific subunits. The Comet assay and ɣH2AX signal measurements were performed in order to assess the DNA damage amount and recognition. Finally, quantitative real-time PCR of target proteins was applied to differentiate between transcriptional and post-translational regulation. RESULTS Calcium-dependent calpain proteases, in particular calpain-2, are more abundant in glioblastoma compared to normal brain and increased in patient-matched initial and recurrent glioblastomas. On the cellular level, pharmacological calpain inhibition increased the sensitivities of primary glioblastoma cells towards TMZ. A genetic knockdown of calpain-2 in U251 cells led to increased caspase-3 cleavage and sensitivity to neocarzinostatin, which rapidly induces DNA strand breakage. We hypothesize that calpain-2 causes desensitization of tumor cells against TMZ by preventing strong DNA damage and subsequent apoptosis via post-translational TP53 inhibition. Indeed, proteomic comparison of U251 control vs. U251 calpain-2 knockdown cells highlights perturbed levels of numerous proteins involved in DNA damage response and downstream pathways affecting TP53 and NF-κB signaling. TP53 showed increased protein abundance, but no transcriptional regulation. CONCLUSION TMZ-induced cell death in the presence of calpain-2 expression appears to favor DNA repair and promote cell survival. We conclude from our experiments that calpain-2 expression represents a proteomic mode that is associated with higher resistance via "priming" GBM cells to TMZ chemotherapy. Thus, calpain-2 could serve as a prognostic factor for GBM outcome.
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Affiliation(s)
- Maren Nicole Stillger
- Institute for Surgical Pathology, Faculty of Medicine, Medical Center - University of Freiburg, University of Freiburg, Freiburg, Germany.,Faculty of Biology, Albert-Ludwigs-University Freiburg, Freiburg, Germany
| | - Chia-Yi Chen
- Institute for Surgical Pathology, Faculty of Medicine, Medical Center - University of Freiburg, University of Freiburg, Freiburg, Germany
| | - Zon Weng Lai
- Internal Medicine Research Unit, Pfizer Inc, Cambridge, MA, USA
| | - Mujia Li
- Institute for Surgical Pathology, Faculty of Medicine, Medical Center - University of Freiburg, University of Freiburg, Freiburg, Germany.,Department of Pharmaceutical Biology and Biotechnology, Institute of Pharmaceutical Sciences, University of Freiburg, Freiburg, Germany
| | - Agnes Schäfer
- Department of Neurosurgery, Philipps-University Marburg, Marburg, Germany
| | - Axel Pagenstecher
- Institute of Neuropathology, Philipps-University, Marburg, Germany.,Center for Mind, Brain and Behavior, CMBB, Marburg University, Hans-Meerwein-Strasse 6, 35032, Marburg, Germany
| | - Christopher Nimsky
- Department of Neurosurgery, Philipps-University Marburg, Marburg, Germany.,Center for Mind, Brain and Behavior, CMBB, Marburg University, Hans-Meerwein-Strasse 6, 35032, Marburg, Germany
| | - Jörg Walter Bartsch
- Department of Neurosurgery, Philipps-University Marburg, Marburg, Germany. .,Center for Mind, Brain and Behavior, CMBB, Marburg University, Hans-Meerwein-Strasse 6, 35032, Marburg, Germany. .,Philipps-University Marburg, Laboratory, Department of Neurosurgery, University Hospital Marburg, Baldingerstr., 35033, Marburg, Germany.
| | - Oliver Schilling
- Institute for Surgical Pathology, Faculty of Medicine, Medical Center - University of Freiburg, University of Freiburg, Freiburg, Germany.,German Cancer Consortium (DKTK) and German Cancer Research Center (DKFZ), Heidelberg, Germany
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3
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Georgieva M, Vassileva V. Stress Management in Plants: Examining Provisional and Unique Dose-Dependent Responses. Int J Mol Sci 2023; 24:ijms24065105. [PMID: 36982199 PMCID: PMC10049000 DOI: 10.3390/ijms24065105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2023] [Revised: 03/05/2023] [Accepted: 03/06/2023] [Indexed: 03/11/2023] Open
Abstract
The purpose of this review is to critically evaluate the effects of different stress factors on higher plants, with particular attention given to the typical and unique dose-dependent responses that are essential for plant growth and development. Specifically, this review highlights the impact of stress on genome instability, including DNA damage and the molecular, physiological, and biochemical mechanisms that generate these effects. We provide an overview of the current understanding of predictable and unique dose-dependent trends in plant survival when exposed to low or high doses of stress. Understanding both the negative and positive impacts of stress responses, including genome instability, can provide insights into how plants react to different levels of stress, yielding more accurate predictions of their behavior in the natural environment. Applying the acquired knowledge can lead to improved crop productivity and potential development of more resilient plant varieties, ensuring a sustainable food source for the rapidly growing global population.
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4
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Jung P, Schmalbrock L, Wirth M. CRISPR Activation/Interference Screen to Identify Genetic Networks in HDAC-Inhibitor-Resistant Cells. Methods Mol Biol 2023; 2589:429-454. [PMID: 36255641 DOI: 10.1007/978-1-0716-2788-4_28] [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] [Indexed: 06/16/2023]
Abstract
Epigenetic alterations have been identified in various tumor types. In part, these alterations are mediated via increased histone deacetylase activity. Although preclinical results of monotherapies with histone deacetylase inhibitors (HDACi) are promising, success in clinical trials is limited. Reasons for these limitations may be de novo or acquired resistance to HDAC inhibitors that could be overcome with rational combination therapies. This requires knowledge of resistance mechanism along with the involved genetic networks. One way to identify such genetic networks is the implementation of a CRISPR-based technology allowing transcriptional repression (CRISPRi) and activation (CRISPRa) at a genome-wide scale. We describe a simple approach to amplify and validate sgRNA libraries, generate a myeloid progenitor cell line expressing catalytically dead Cas9 (dCas9) fusion proteins with transcriptional effectors to repress or activate genetic regions of interest and demonstrate a complementary genome-wide HDACi resistance screening approach. Furthermore, we present bioinformatics tools for quality control and analysis of the sequencing data.
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Affiliation(s)
- Paul Jung
- Department of Hematology, Oncology and Cancer Immunology, Campus Benjamin Franklin, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Laura Schmalbrock
- Department of Hematology, Oncology and Cancer Immunology, Campus Benjamin Franklin, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Matthias Wirth
- Department of Hematology, Oncology and Cancer Immunology, Campus Benjamin Franklin, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany.
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5
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El Nachef L, Berthel E, Ferlazzo ML, Le Reun E, Al-Choboq J, Restier-Verlet J, Granzotto A, Sonzogni L, Bourguignon M, Foray N. Cancer and Radiosensitivity Syndromes: Is Impaired Nuclear ATM Kinase Activity the Primum Movens? Cancers (Basel) 2022; 14:cancers14246141. [PMID: 36551628 PMCID: PMC9776478 DOI: 10.3390/cancers14246141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 12/01/2022] [Accepted: 12/09/2022] [Indexed: 12/15/2022] Open
Abstract
There are a number of genetic syndromes associated with both high cancer risk and clinical radiosensitivity. However, the link between these two notions remains unknown. Particularly, some cancer syndromes are caused by mutations in genes involved in DNA damage signaling and repair. How are the DNA sequence errors propagated and amplified to cause cell transformation? Conversely, some cancer syndromes are caused by mutations in genes involved in cell cycle checkpoint control. How is misrepaired DNA damage produced? Lastly, certain genes, considered as tumor suppressors, are not involved in DNA damage signaling and repair or in cell cycle checkpoint control. The mechanistic model based on radiation-induced nucleoshuttling of the ATM kinase (RIANS), a major actor of the response to ionizing radiation, may help in providing a unified explanation of the link between cancer proneness and radiosensitivity. In the frame of this model, a given protein may ensure its own specific function but may also play additional biological role(s) as an ATM phosphorylation substrate in cytoplasm. It appears that the mutated proteins that cause the major cancer and radiosensitivity syndromes are all ATM phosphorylation substrates, and they generally localize in the cytoplasm when mutated. The relevance of the RIANS model is discussed by considering different categories of the cancer syndromes.
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Affiliation(s)
- Laura El Nachef
- Inserm, U1296 Unit, Radiation: Defense, Health and Environment, Centre Léon-Bérard, 69008 Lyon, France
| | - Elise Berthel
- Inserm, U1296 Unit, Radiation: Defense, Health and Environment, Centre Léon-Bérard, 69008 Lyon, France
| | - Mélanie L. Ferlazzo
- Inserm, U1296 Unit, Radiation: Defense, Health and Environment, Centre Léon-Bérard, 69008 Lyon, France
| | - Eymeric Le Reun
- Inserm, U1296 Unit, Radiation: Defense, Health and Environment, Centre Léon-Bérard, 69008 Lyon, France
| | - Joelle Al-Choboq
- Inserm, U1296 Unit, Radiation: Defense, Health and Environment, Centre Léon-Bérard, 69008 Lyon, France
| | - Juliette Restier-Verlet
- Inserm, U1296 Unit, Radiation: Defense, Health and Environment, Centre Léon-Bérard, 69008 Lyon, France
| | - Adeline Granzotto
- Inserm, U1296 Unit, Radiation: Defense, Health and Environment, Centre Léon-Bérard, 69008 Lyon, France
| | - Laurène Sonzogni
- Inserm, U1296 Unit, Radiation: Defense, Health and Environment, Centre Léon-Bérard, 69008 Lyon, France
| | - Michel Bourguignon
- Inserm, U1296 Unit, Radiation: Defense, Health and Environment, Centre Léon-Bérard, 69008 Lyon, France
- Department of Biophysics and Nuclear Medicine, Université Paris Saclay (UVSQ), 78035 Versailles, France
| | - Nicolas Foray
- Inserm, U1296 Unit, Radiation: Defense, Health and Environment, Centre Léon-Bérard, 69008 Lyon, France
- Correspondence: ; Tel.: +33-04-7878-2828
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6
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Kumari S, Sharma S, Advani D, Khosla A, Kumar P, Ambasta RK. Unboxing the molecular modalities of mutagens in cancer. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:62111-62159. [PMID: 34611806 PMCID: PMC8492102 DOI: 10.1007/s11356-021-16726-w] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2021] [Accepted: 09/22/2021] [Indexed: 04/16/2023]
Abstract
The etiology of the majority of human cancers is associated with a myriad of environmental causes, including physical, chemical, and biological factors. DNA damage induced by such mutagens is the initial step in the process of carcinogenesis resulting in the accumulation of mutations. Mutational events are considered the major triggers for introducing genetic and epigenetic insults such as DNA crosslinks, single- and double-strand DNA breaks, formation of DNA adducts, mismatched bases, modification in histones, DNA methylation, and microRNA alterations. However, DNA repair mechanisms are devoted to protect the DNA to ensure genetic stability, any aberrations in these calibrated mechanisms provoke cancer occurrence. Comprehensive knowledge of the type of mutagens and carcinogens and the influence of these agents in DNA damage and cancer induction is crucial to develop rational anticancer strategies. This review delineated the molecular mechanism of DNA damage and the repair pathways to provide a deep understanding of the molecular basis of mutagenicity and carcinogenicity. A relationship between DNA adduct formation and cancer incidence has also been summarized. The mechanistic basis of inflammatory response and oxidative damage triggered by mutagens in tumorigenesis has also been highlighted. We elucidated the interesting interplay between DNA damage response and immune system mechanisms. We addressed the current understanding of DNA repair targeted therapies and DNA damaging chemotherapeutic agents for cancer treatment and discussed how antiviral agents, anti-inflammatory drugs, and immunotherapeutic agents combined with traditional approaches lay the foundations for future cancer therapies.
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Affiliation(s)
- Smita Kumari
- Molecular Neuroscience and Functional Genomics Laboratory, Department of Biotechnology, Delhi Technological University, Shahbad Daulatpur, Bawana Road, Delhi, 110042, India
| | - Sudhanshu Sharma
- Molecular Neuroscience and Functional Genomics Laboratory, Department of Biotechnology, Delhi Technological University, Shahbad Daulatpur, Bawana Road, Delhi, 110042, India
| | - Dia Advani
- Molecular Neuroscience and Functional Genomics Laboratory, Department of Biotechnology, Delhi Technological University, Shahbad Daulatpur, Bawana Road, Delhi, 110042, India
| | - Akanksha Khosla
- Molecular Neuroscience and Functional Genomics Laboratory, Department of Biotechnology, Delhi Technological University, Shahbad Daulatpur, Bawana Road, Delhi, 110042, India
| | - Pravir Kumar
- Molecular Neuroscience and Functional Genomics Laboratory, Department of Biotechnology, Delhi Technological University, Shahbad Daulatpur, Bawana Road, Delhi, 110042, India
| | - Rashmi K Ambasta
- Molecular Neuroscience and Functional Genomics Laboratory, Department of Biotechnology, Delhi Technological University, Shahbad Daulatpur, Bawana Road, Delhi, 110042, India.
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7
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Processing DNA lesions during mitosis to prevent genomic instability. Biochem Soc Trans 2022; 50:1105-1118. [PMID: 36040211 PMCID: PMC9444068 DOI: 10.1042/bst20220049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 07/29/2022] [Accepted: 08/01/2022] [Indexed: 11/17/2022]
Abstract
Failure of cells to process toxic double-strand breaks (DSBs) constitutes a major intrinsic source of genome instability, a hallmark of cancer. In contrast with interphase of the cell cycle, canonical repair pathways in response to DSBs are inactivated in mitosis. Although cell cycle checkpoints prevent transmission of DNA lesions into mitosis under physiological condition, cancer cells frequently display mitotic DNA lesions. In this review, we aim to provide an overview of how mitotic cells process lesions that escape checkpoint surveillance. We outline mechanisms that regulate the mitotic DNA damage response and the different types of lesions that are carried over to mitosis, with a focus on joint DNA molecules arising from under-replication and persistent recombination intermediates, as well as DNA catenanes. Additionally, we discuss the processing pathways that resolve each of these lesions in mitosis. Finally, we address the acute and long-term consequences of unresolved mitotic lesions on cellular fate and genome stability.
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8
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Welch G, Tsai LH. Mechanisms of DNA damage-mediated neurotoxicity in neurodegenerative disease. EMBO Rep 2022; 23:e54217. [PMID: 35499251 PMCID: PMC9171412 DOI: 10.15252/embr.202154217] [Citation(s) in RCA: 44] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Revised: 03/18/2022] [Accepted: 04/19/2022] [Indexed: 12/26/2022] Open
Abstract
Neurons are highly susceptible to DNA damage accumulation due to their large energy requirements, elevated transcriptional activity, and long lifespan. While newer research has shown that DNA breaks and mutations may facilitate neuron diversity during development and neuronal function throughout life, a wealth of evidence indicates deficient DNA damage repair underlies many neurological disorders, especially age-associated neurodegenerative diseases. Recently, efforts to clarify the molecular link between DNA damage and neurodegeneration have improved our understanding of how the genomic location of DNA damage and defunct repair proteins impact neuron health. Additionally, work establishing a role for senescence in the aging and diseased brain reveals DNA damage may play a central role in neuroinflammation associated with neurodegenerative disease.
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Affiliation(s)
- Gwyneth Welch
- Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA, USA.,Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Li-Huei Tsai
- Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA, USA.,Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
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9
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Machour FE, Abu-Zhayia ER, Awwad SW, Bidany-Mizrahi T, Meinke S, Bishara LA, Heyd F, Aqeilan RI, Ayoub N. RBM6 splicing factor promotes homologous recombination repair of double-strand breaks and modulates sensitivity to chemotherapeutic drugs. Nucleic Acids Res 2021; 49:11708-11727. [PMID: 34718714 PMCID: PMC8599755 DOI: 10.1093/nar/gkab976] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Revised: 09/26/2021] [Accepted: 10/07/2021] [Indexed: 12/13/2022] Open
Abstract
RNA-binding proteins regulate mRNA processing and translation and are often aberrantly expressed in cancer. The RNA-binding motif protein 6, RBM6, is a known alternative splicing factor that harbors tumor suppressor activity and is frequently mutated in human cancer. Here, we identify RBM6 as a novel regulator of homologous recombination (HR) repair of DNA double-strand breaks (DSBs). Mechanistically, we show that RBM6 regulates alternative splicing-coupled nonstop-decay of a positive HR regulator, Fe65/APBB1. RBM6 knockdown leads to a severe reduction in Fe65 protein levels and consequently impairs HR of DSBs. Accordingly, RBM6-deficient cancer cells are vulnerable to ATM and PARP inhibition and show remarkable sensitivity to cisplatin. Concordantly, cisplatin administration inhibits the growth of breast tumor devoid of RBM6 in mouse xenograft model. Furthermore, we observe that RBM6 protein is significantly lost in metastatic breast tumors compared with primary tumors, thus suggesting RBM6 as a potential therapeutic target of advanced breast cancer. Collectively, our results elucidate the link between the multifaceted roles of RBM6 in regulating alternative splicing and HR of DSBs that may contribute to tumorigenesis, and pave the way for new avenues of therapy for RBM6-deficient tumors.
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Affiliation(s)
- Feras E Machour
- Department of Biology, Technion - Israel Institute of Technology, Haifa 3200003, Israel
| | - Enas R Abu-Zhayia
- Department of Biology, Technion - Israel Institute of Technology, Haifa 3200003, Israel
| | - Samah W Awwad
- Department of Biology, Technion - Israel Institute of Technology, Haifa 3200003, Israel
| | - Tirza Bidany-Mizrahi
- The Concern Foundation Laboratories, The Lautenberg Center for Immunology and Cancer Research, Department of Immunology and Cancer Research-IMRIC, Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem 91120, Israel
| | - Stefan Meinke
- Freie Universität Berlin, Institute of Chemistry and Biochemistry, Laboratory of RNA Biochemistry, Takustrasse 6, 14195 Berlin, Germany
| | - Laila A Bishara
- Department of Biology, Technion - Israel Institute of Technology, Haifa 3200003, Israel
| | - Florian Heyd
- Freie Universität Berlin, Institute of Chemistry and Biochemistry, Laboratory of RNA Biochemistry, Takustrasse 6, 14195 Berlin, Germany
| | - Rami I Aqeilan
- The Concern Foundation Laboratories, The Lautenberg Center for Immunology and Cancer Research, Department of Immunology and Cancer Research-IMRIC, Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem 91120, Israel
| | - Nabieh Ayoub
- Department of Biology, Technion - Israel Institute of Technology, Haifa 3200003, Israel
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10
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Herviou L, Ovejero S, Izard F, Karmous-Gadacha O, Gourzones C, Bellanger C, De Smedt E, Ma A, Vincent L, Cartron G, Jin J, De Bruyne E, Grimaud C, Julien E, Moreaux J. Targeting the methyltransferase SETD8 impairs tumor cell survival and overcomes drug resistance independently of p53 status in multiple myeloma. Clin Epigenetics 2021; 13:174. [PMID: 34530900 PMCID: PMC8447659 DOI: 10.1186/s13148-021-01160-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Accepted: 08/27/2021] [Indexed: 01/04/2023] Open
Abstract
Background Multiple myeloma (MM) is a malignancy of plasma cells that largely remains incurable. The search for new therapeutic targets is therefore essential. In addition to a wide panel of genetic mutations, epigenetic alterations also appear as important players in the development of this cancer, thereby offering the possibility to reveal novel approaches and targets for effective therapeutic intervention. Results Here, we show that a higher expression of the lysine methyltransferase SETD8, which is responsible for the mono-methylation of histone H4 at lysine 20, is an adverse prognosis factor associated with a poor outcome in two cohorts of newly diagnosed patients. Primary malignant plasma cells are particularly addicted to the activity of this epigenetic enzyme. Indeed, the inhibition of SETD8 by the chemical compound UNC-0379 and the subsequent decrease in histone H4 methylation at lysine 20 are highly toxic in MM cells compared to normal cells from the bone marrow microenvironment. At the molecular level, RNA sequencing and functional studies revealed that SETD8 inhibition induces a mature non-proliferating plasma cell signature and, as observed in other cancers, triggers an activation of the tumor suppressor p53, which together cause an impairment of myeloma cell proliferation and survival. However, a deadly level of replicative stress was also observed in p53-deficient myeloma cells treated with UNC-0379, indicating that the cytotoxicity associated with SETD8 inhibition is not necessarily dependent on p53 activation. Consistent with this, UNC-0379 triggers a p53-independent nucleolar stress characterized by nucleolin delocalization and reduction of nucleolar RNA synthesis. Finally, we showed that SETD8 inhibition is strongly synergistic with melphalan and may overcome resistance to this alkylating agent widely used in MM treatment. Conclusions Altogether, our data indicate that the up-regulation of the epigenetic enzyme SETD8 is associated with a poor outcome and the deregulation of major signaling pathways in MM. Moreover, we provide evidences that myeloma cells are dependent on SETD8 activity and its pharmacological inhibition synergizes with melphalan, which could be beneficial to improve MM treatment in high-risk patients whatever their status for p53. Supplementary Information The online version contains supplementary material available at 10.1186/s13148-021-01160-z.
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Affiliation(s)
- Laurie Herviou
- IGH, CNRS, Univ Montpellier, Montpellier, France.,Laboratory for Monitoring Innovative Therapies, Department of Biological Hematology, CHU Montpellier, Montpellier, France.,University of Montpellier, 34090, Montpellier, France
| | - Sara Ovejero
- IGH, CNRS, Univ Montpellier, Montpellier, France.,Laboratory for Monitoring Innovative Therapies, Department of Biological Hematology, CHU Montpellier, Montpellier, France.,University of Montpellier, 34090, Montpellier, France
| | - Fanny Izard
- Institut de Recherche en Cancérologie de Montpellier (IRCM), INSERM U1194, Institut Régional du Cancer (ICM), 34298, Montpellier, France.,University of Montpellier, 34090, Montpellier, France
| | - Ouissem Karmous-Gadacha
- Laboratory for Monitoring Innovative Therapies, Department of Biological Hematology, CHU Montpellier, Montpellier, France
| | | | | | - Eva De Smedt
- Department of Hematology and Immunology-Myeloma Center Brussels, Vrije Universiteit Brussel, Brussels, Belgium
| | - Anqi Ma
- Mount Sinai Center for Therapeutics Discovery, Departments of Pharmacological Sciences and Oncological Sciences, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Laure Vincent
- Department of Clinical Hematology, CHU Montpellier, Montpellier, France
| | - Guillaume Cartron
- University of Montpellier, 34090, Montpellier, France.,Department of Clinical Hematology, CHU Montpellier, Montpellier, France
| | - Jian Jin
- Mount Sinai Center for Therapeutics Discovery, Departments of Pharmacological Sciences and Oncological Sciences, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Elke De Bruyne
- Department of Hematology and Immunology-Myeloma Center Brussels, Vrije Universiteit Brussel, Brussels, Belgium
| | - Charlotte Grimaud
- Institut de Recherche en Cancérologie de Montpellier (IRCM), INSERM U1194, Institut Régional du Cancer (ICM), 34298, Montpellier, France.,University of Montpellier, 34090, Montpellier, France.,Centre National de La Recherche Scientifique (CNRS), 34293, Montpellier, France
| | - Eric Julien
- Institut de Recherche en Cancérologie de Montpellier (IRCM), INSERM U1194, Institut Régional du Cancer (ICM), 34298, Montpellier, France. .,University of Montpellier, 34090, Montpellier, France. .,Centre National de La Recherche Scientifique (CNRS), 34293, Montpellier, France.
| | - Jérôme Moreaux
- IGH, CNRS, Univ Montpellier, Montpellier, France. .,Laboratory for Monitoring Innovative Therapies, Department of Biological Hematology, CHU Montpellier, Montpellier, France. .,University of Montpellier, 34090, Montpellier, France. .,Institut Universitaire de France (IUF), Paris, France.
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11
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Revisiting the BRCA-pathway through the lens of replication gap suppression: "Gaps determine therapy response in BRCA mutant cancer". DNA Repair (Amst) 2021; 107:103209. [PMID: 34419699 DOI: 10.1016/j.dnarep.2021.103209] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2021] [Revised: 08/06/2021] [Accepted: 08/07/2021] [Indexed: 12/12/2022]
Abstract
The toxic lesion emanating from chemotherapy that targets the DNA was initially debated, but eventually the DNA double strand break (DSB) ultimately prevailed. The reasoning was in part based on the perception that repairing a fractured chromosome necessitated intricate processing or condemned the cell to death. Genetic evidence for the DSB model was also provided by the extreme sensitivity of cells that were deficient in DSB repair. In particular, sensitivity characterized cells harboring mutations in the hereditary breast/ovarian cancer genes, BRCA1 or BRCA2, that function in the repair of DSBs by homologous recombination (HR). Along with functions in HR, BRCA proteins were found to prevent DSBs by protecting stalled replication forks from nuclease degradation. Coming full-circle, BRCA mutant cancer cells that gained resistance to genotoxic chemotherapy often displayed restored DNA repair by HR and/or restored fork protection (FP) implicating that the therapy was tolerated when DSB repair was intact or DSBs were prevented. Despite this well-supported paradigm that has been the impetus for targeted cancer therapy, here we argue that the toxic DNA lesion conferring response is instead single stranded DNA (ssDNA) gaps. We discuss the evidence that persistent ssDNA gaps formed in the wake of DNA replication rather than DSBs are responsible for cell killing following treatment with genotoxic chemotherapeutic agents. We also highlight that proteins, such as BRCA1, BRCA2, and RAD51 known for canonical DSB repair also have critical roles in normal replication as well as replication gap suppression (RGS) and repair. We review the literature that supports the idea that widespread gap induction proximal to treatment triggers apoptosis in a process that does not need or stem from DSB induction. Lastly, we discuss the clinical evidence for gaps and how to exploit them to enhance genotoxic chemotherapy response.
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12
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Spencer PS, Kisby GE. Role of Hydrazine-Related Chemicals in Cancer and Neurodegenerative Disease. Chem Res Toxicol 2021; 34:1953-1969. [PMID: 34379394 DOI: 10.1021/acs.chemrestox.1c00150] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Hydrazine-related chemicals (HRCs) with carcinogenic and neurotoxic potential are found in certain mushrooms and plants used for food and in products employed in various industries, including aerospace. Their propensity to induce DNA damage (mostly O6-, N7- and 8-oxo-guanine lesions) resulting in multiple downstream effects is linked with both cancer and neurological disease. For cycling cells, unrepaired DNA damage leads to mutation and uncontrolled mitosis. By contrast, postmitotic neurons attempt to re-enter the cell cycle but undergo apoptosis or nonapoptotic cell death. Biomarkers of exposure to HRCs can be used to explore whether these substances are risk factors for sporadic amyotrophic laterals sclerosis and other noninherited neurodegenerative diseases, which is the focus of this paper.
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Affiliation(s)
- Peter S Spencer
- Oregon Health and Science University, Portland, Oregon 97239, United States
| | - Glen E Kisby
- College of Osteopathic Medicine of the Pacific Northwest, Western University of Health Sciences, Lebanon, Oregon 97355, United States
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13
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Zell J, Rota Sperti F, Britton S, Monchaud D. DNA folds threaten genetic stability and can be leveraged for chemotherapy. RSC Chem Biol 2021; 2:47-76. [PMID: 35340894 PMCID: PMC8885165 DOI: 10.1039/d0cb00151a] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Accepted: 09/20/2020] [Indexed: 12/22/2022] Open
Abstract
Damaging DNA is a current and efficient strategy to fight against cancer cell proliferation. Numerous mechanisms exist to counteract DNA damage, collectively referred to as the DNA damage response (DDR) and which are commonly dysregulated in cancer cells. Precise knowledge of these mechanisms is necessary to optimise chemotherapeutic DNA targeting. New research on DDR has uncovered a series of promising therapeutic targets, proteins and nucleic acids, with application notably via an approach referred to as combination therapy or combinatorial synthetic lethality. In this review, we summarise the cornerstone discoveries which gave way to the DNA being considered as an anticancer target, and the manipulation of DDR pathways as a valuable anticancer strategy. We describe in detail the DDR signalling and repair pathways activated in response to DNA damage. We then summarise the current understanding of non-B DNA folds, such as G-quadruplexes and DNA junctions, when they are formed and why they can offer a more specific therapeutic target compared to that of canonical B-DNA. Finally, we merge these subjects to depict the new and highly promising chemotherapeutic strategy which combines enhanced-specificity DNA damaging and DDR targeting agents. This review thus highlights how chemical biology has given rise to significant scientific advances thanks to resolutely multidisciplinary research efforts combining molecular and cell biology, chemistry and biophysics. We aim to provide the non-specialist reader a gateway into this exciting field and the specialist reader with a new perspective on the latest results achieved and strategies devised.
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Affiliation(s)
- Joanna Zell
- Institut de Chimie Moléculaire de l'Université de Bourgogne, ICMUB CNRS UMR 6302, UBFC Dijon France
| | - Francesco Rota Sperti
- Institut de Chimie Moléculaire de l'Université de Bourgogne, ICMUB CNRS UMR 6302, UBFC Dijon France
| | - Sébastien Britton
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS Toulouse France
- Équipe Labellisée la Ligue Contre le Cancer 2018 Toulouse France
| | - David Monchaud
- Institut de Chimie Moléculaire de l'Université de Bourgogne, ICMUB CNRS UMR 6302, UBFC Dijon France
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14
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Kanakamani S, Suresh PS, Venkatesh T. Regulation of processing bodies: From viruses to cancer epigenetic machinery. Cell Biol Int 2020; 45:708-719. [PMID: 33325125 DOI: 10.1002/cbin.11527] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 10/17/2020] [Accepted: 12/13/2020] [Indexed: 11/08/2022]
Abstract
Processing bodies (PBs) are 100-300 nm cytoplasmic messenger ribonucleoprotein particle (mRNP) granules that regulate eukaryotic gene expression. These cytoplasmic compartments harbor messenger RNAs (mRNAs) and several proteins involved in mRNA decay, microRNA silencing, nonsense-mediated mRNA decay, and splicing. Though membrane-less, PB structures are maintained by RNA-protein and protein-protein interactions. PB proteins have intrinsically disordered regions and low complexity domains, which account for its liquid to liquid phase separation. In addition to being dynamic and actively involved in the exchange of materials with other mRNPs and organelles, they undergo changes on various cellular cues and environmental stresses, including viral infections. Interestingly, several PB proteins are individually implicated in cancer development, and no study has addressed the effects on PB dynamics after epigenetic modifications of cancer-associated PB genes. In the current review, we summarize modulations undergone by P bodies or P body components upon viral infections. Furthermore, we discuss the selective and widely investigated PB proteins that undergo methylation changes in cancer and their potential as biomarkers.
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Affiliation(s)
- Sunmathy Kanakamani
- Department of Biochemistry and Molecular Biology, Central University of Kerala, Kasargod, India
| | - Padmanaban S Suresh
- Department of Biotechnology, National Institute of Technology Calicut, Calicut, India
| | - Thejaswini Venkatesh
- Department of Biochemistry and Molecular Biology, Central University of Kerala, Kasargod, India
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15
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Functional Screening Techniques to Identify Long Non-Coding RNAs as Therapeutic Targets in Cancer. Cancers (Basel) 2020; 12:cancers12123695. [PMID: 33317042 PMCID: PMC7763270 DOI: 10.3390/cancers12123695] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 12/06/2020] [Accepted: 12/07/2020] [Indexed: 12/16/2022] Open
Abstract
Simple Summary Long non-coding RNAs (lncRNAs) are a recently discovered class of molecules in the cell, with potential to be utilized as therapeutic targets in cancer. A number of lncRNAs have been described to play important roles in tumor progression and drive molecular processes involved in cell proliferation, apoptosis or invasion. However, the vast majority of lncRNAs have not been studied in the context of cancer thus far. With the advent of CRISPR/Cas genome editing, high-throughput functional screening approaches to identify lncRNAs that impact cancer growth are becoming more accessible. Here, we review currently available methods to study hundreds to thousands of lncRNAs in parallel to elucidate their role in tumorigenesis and cancer progression. Abstract Recent technological advancements such as CRISPR/Cas-based systems enable multiplexed, high-throughput screening for new therapeutic targets in cancer. While numerous functional screens have been performed on protein-coding genes to date, long non-coding RNAs (lncRNAs) represent an emerging class of potential oncogenes and tumor suppressors, with only a handful of large-scale screens performed thus far. Here, we review in detail currently available screening approaches to identify new lncRNA drivers of tumorigenesis and tumor progression. We discuss the various approaches of genomic and transcriptional targeting using CRISPR/Cas9, as well as methods to post-transcriptionally target lncRNAs via RNA interference (RNAi), antisense oligonucleotides (ASOs) and CRISPR/Cas13. We discuss potential advantages, caveats and future applications of each method to provide an overview and guide on investigating lncRNAs as new therapeutic targets in cancer.
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16
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Chen Y, Geng A, Zhang W, Qian Z, Wan X, Jiang Y, Mao Z. Fight to the bitter end: DNA repair and aging. Ageing Res Rev 2020; 64:101154. [PMID: 32977059 DOI: 10.1016/j.arr.2020.101154] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 08/05/2020] [Accepted: 08/19/2020] [Indexed: 12/11/2022]
Abstract
DNA carries the genetic information that directs complex biological processes; thus, maintaining a stable genome is critical for individual growth and development and for human health. DNA repair is a fundamental and conserved mechanism responsible for mending damaged DNA and restoring genomic stability, while its deficiency is closely related to multiple human disorders. In recent years, remarkable progress has been made in the field of DNA repair and aging. Here, we will extensively discuss the relationship among DNA damage, DNA repair, aging and aging-associated diseases based on the latest research. In addition, the possible role of DNA repair in several potential rejuvenation strategies will be discussed. Finally, we will also review the emerging methods that may facilitate future research on DNA repair.
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17
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Panzarino NJ, Krais JJ, Cong K, Peng M, Mosqueda M, Nayak SU, Bond SM, Calvo JA, Doshi MB, Bere M, Ou J, Deng B, Zhu LJ, Johnson N, Cantor SB. Replication Gaps Underlie BRCA Deficiency and Therapy Response. Cancer Res 2020; 81:1388-1397. [PMID: 33184108 PMCID: PMC8026497 DOI: 10.1158/0008-5472.can-20-1602] [Citation(s) in RCA: 89] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 09/02/2020] [Accepted: 11/09/2020] [Indexed: 11/16/2022]
Abstract
Defects in DNA repair and the protection of stalled DNA replication forks are thought to underlie the chemosensitivity of tumors deficient in the hereditary breast cancer genes BRCA1 and BRCA2 (BRCA). Challenging this assumption are recent findings that indicate chemotherapies, such as cisplatin used to treat BRCA-deficient tumors, do not initially cause DNA double-strand breaks (DSB). Here, we show that ssDNA replication gaps underlie the hypersensitivity of BRCA-deficient cancer and that defects in homologous recombination (HR) or fork protection (FP) do not. In BRCA-deficient cells, ssDNA gaps developed because replication was not effectively restrained in response to stress. Gap suppression by either restoration of fork restraint or gap filling conferred therapy resistance in tissue culture and BRCA patient tumors. In contrast, restored FP and HR could be uncoupled from therapy resistance when gaps were present. Moreover, DSBs were not detected after therapy when apoptosis was inhibited, supporting a framework in which DSBs are not directly induced by genotoxic agents, but rather are induced from cell death nucleases and are not fundamental to the mechanism of action of genotoxic agents. Together, these data indicate that ssDNA replication gaps underlie the BRCA cancer phenotype, "BRCAness," and we propose they are fundamental to the mechanism of action of genotoxic chemotherapies. SIGNIFICANCE: This study suggests that ssDNA replication gaps are fundamental to the toxicity of genotoxic agents and underlie the BRCA-cancer phenotype "BRCAness," yielding promising biomarkers, targets, and opportunities to resensitize refractory disease.See related commentary by Canman, p. 1214.
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Affiliation(s)
| | - John J Krais
- Fox Chase Cancer Center, Philadelphia, Pennsylvania
| | - Ke Cong
- University of Massachusetts Medical School, Worcester, Massachusetts
| | - Min Peng
- University of Massachusetts Medical School, Worcester, Massachusetts
| | - Michelle Mosqueda
- University of Massachusetts Medical School, Worcester, Massachusetts
| | - Sumeet U Nayak
- University of Massachusetts Medical School, Worcester, Massachusetts
| | - Samuel M Bond
- University of Massachusetts Medical School, Worcester, Massachusetts
| | - Jennifer A Calvo
- University of Massachusetts Medical School, Worcester, Massachusetts
| | - Mihir B Doshi
- University of Massachusetts Medical School, Worcester, Massachusetts
| | - Matt Bere
- University of Massachusetts Medical School, Worcester, Massachusetts
| | - Jianhong Ou
- University of Massachusetts Medical School, Worcester, Massachusetts
| | - Bin Deng
- The University of Vermont, Burlington, Vermont
| | - Lihua J Zhu
- University of Massachusetts Medical School, Worcester, Massachusetts
| | - Neil Johnson
- Fox Chase Cancer Center, Philadelphia, Pennsylvania
| | - Sharon B Cantor
- University of Massachusetts Medical School, Worcester, Massachusetts.
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Protection from Ultraviolet Damage and Photocarcinogenesis by Vitamin D Compounds. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1268:227-253. [PMID: 32918222 DOI: 10.1007/978-3-030-46227-7_12] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Exposure of skin cells to UV radiation results in DNA damage, which if inadequately repaired, may cause mutations. UV-induced DNA damage and reactive oxygen and nitrogen species also cause local and systemic suppression of the adaptive immune system. Together, these changes underpin the development of skin tumours. The hormone derived from vitamin D, calcitriol (1,25-dihydroxyvitamin D3) and other related compounds, working via the vitamin D receptor and at least in part through endoplasmic reticulum protein 57 (ERp57), reduce cyclobutane pyrimidine dimers and oxidative DNA damage in keratinocytes and other skin cell types after UV. Calcitriol and related compounds enhance DNA repair in keratinocytes, in part through decreased reactive oxygen species, increased p53 expression and/or activation, increased repair proteins and increased energy availability in the cell when calcitriol is present after UV exposure. There is mitochondrial damage in keratinocytes after UV. In the presence of calcitriol, but not vehicle, glycolysis is increased after UV, along with increased energy-conserving autophagy and changes consistent with enhanced mitophagy. Reduced DNA damage and reduced ROS/RNS should help reduce UV-induced immune suppression. Reduced UV immune suppression is observed after topical treatment with calcitriol and related compounds in hairless mice. These protective effects of calcitriol and related compounds presumably contribute to the observed reduction in skin tumour formation in mice after chronic exposure to UV followed by topical post-irradiation treatment with calcitriol and some, though not all, related compounds.
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19
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Wassing IE, Esashi F. RAD51: Beyond the break. Semin Cell Dev Biol 2020; 113:38-46. [PMID: 32938550 PMCID: PMC8082279 DOI: 10.1016/j.semcdb.2020.08.010] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 08/14/2020] [Accepted: 08/28/2020] [Indexed: 01/30/2023]
Abstract
As the primary catalyst of homologous recombination (HR) in vertebrates, RAD51 has been extensively studied in the context of repair of double-stranded DNA breaks (DSBs). With recent advances in the understanding of RAD51 function extending beyond DSBs, the importance of RAD51 throughout DNA metabolism has become increasingly clear. Here we review the suggested roles of RAD51 beyond HR, specifically focusing on their interplay with DNA replication and the maintenance of genomic stability, in which RAD51 function emerges as a double-edged sword.
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Affiliation(s)
- Isabel E Wassing
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
| | - Fumiko Esashi
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK.
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20
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Gadgil RY, Romer EJ, Goodman CC, Rider SD, Damewood FJ, Barthelemy JR, Shin-Ya K, Hanenberg H, Leffak M. Replication stress at microsatellites causes DNA double-strand breaks and break-induced replication. J Biol Chem 2020; 295:15378-15397. [PMID: 32873711 DOI: 10.1074/jbc.ra120.013495] [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: 03/18/2020] [Revised: 08/23/2020] [Indexed: 12/12/2022] Open
Abstract
Short tandemly repeated DNA sequences, termed microsatellites, are abundant in the human genome. These microsatellites exhibit length instability and susceptibility to DNA double-strand breaks (DSBs) due to their tendency to form stable non-B DNA structures. Replication-dependent microsatellite DSBs are linked to genome instability signatures in human developmental diseases and cancers. To probe the causes and consequences of microsatellite DSBs, we designed a dual-fluorescence reporter system to detect DSBs at expanded (CTG/CAG) n and polypurine/polypyrimidine (Pu/Py) mirror repeat structures alongside the c-myc replication origin integrated at a single ectopic chromosomal site. Restriction cleavage near the (CTG/CAG)100 microsatellite leads to homology-directed single-strand annealing between flanking AluY elements and reporter gene deletion that can be detected by flow cytometry. However, in the absence of restriction cleavage, endogenous and exogenous replication stressors induce DSBs at the (CTG/CAG)100 and Pu/Py microsatellites. DSBs map to a narrow region at the downstream edge of the (CTG)100 lagging-strand template. (CTG/CAG) n chromosome fragility is repeat length-dependent, whereas instability at the (Pu/Py) microsatellites depends on replication polarity. Strikingly, restriction-generated DSBs and replication-dependent DSBs are not repaired by the same mechanism. Knockdown of DNA damage response proteins increases (Rad18, polymerase (Pol) η, Pol κ) or decreases (Mus81) the sensitivity of the (CTG/CAG)100 microsatellites to replication stress. Replication stress and DSBs at the ectopic (CTG/CAG)100 microsatellite lead to break-induced replication and high-frequency mutagenesis at a flanking thymidine kinase gene. Our results show that non-B structure-prone microsatellites are susceptible to replication-dependent DSBs that cause genome instability.
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Affiliation(s)
- Rujuta Yashodhan Gadgil
- Department of Biochemistry and Molecular Biology, Boonshoft School of Medicine, Wright State University, Dayton, Ohio, USA
| | - Eric J Romer
- Department of Biochemistry and Molecular Biology, Boonshoft School of Medicine, Wright State University, Dayton, Ohio, USA
| | - Caitlin C Goodman
- Department of Biochemistry and Molecular Biology, Boonshoft School of Medicine, Wright State University, Dayton, Ohio, USA
| | - S Dean Rider
- Department of Biochemistry and Molecular Biology, Boonshoft School of Medicine, Wright State University, Dayton, Ohio, USA
| | - French J Damewood
- Department of Biochemistry and Molecular Biology, Boonshoft School of Medicine, Wright State University, Dayton, Ohio, USA
| | - Joanna R Barthelemy
- Department of Biochemistry and Molecular Biology, Boonshoft School of Medicine, Wright State University, Dayton, Ohio, USA
| | - Kazuo Shin-Ya
- Biomedical Information Research Center, National Institute of Advanced Industrial Science and Technology, Tokyo, Japan
| | - Helmut Hanenberg
- Department of Otorhinolaryngology and Head/Neck Surgery, Heinrich Heine University, Düsseldorf, Germany; Department of Pediatrics III, University Children's Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Michael Leffak
- Department of Biochemistry and Molecular Biology, Boonshoft School of Medicine, Wright State University, Dayton, Ohio, USA.
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21
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NEK10 tyrosine phosphorylates p53 and controls its transcriptional activity. Oncogene 2020; 39:5252-5266. [DOI: 10.1038/s41388-020-1361-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Revised: 06/02/2020] [Accepted: 06/08/2020] [Indexed: 11/09/2022]
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22
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Miyahira AK, Sharp A, Ellis L, Jones J, Kaochar S, Larman HB, Quigley DA, Ye H, Simons JW, Pienta KJ, Soule HR. Prostate cancer research: The next generation; report from the 2019 Coffey-Holden Prostate Cancer Academy Meeting. Prostate 2020; 80:113-132. [PMID: 31825540 PMCID: PMC7301761 DOI: 10.1002/pros.23934] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Accepted: 11/18/2019] [Indexed: 12/12/2022]
Abstract
INTRODUCTION The 2019 Coffey-Holden Prostate Cancer Academy (CHPCA) Meeting, "Prostate Cancer Research: The Next Generation," was held 20 to 23 June, 2019, in Los Angeles, California. METHODS The CHPCA Meeting is an annual conference held by the Prostate Cancer Foundation, that is uniquely structured to stimulate intense discussion surrounding topics most critical to accelerating prostate cancer research and the discovery of new life-extending treatments for patients. The 7th Annual CHPCA Meeting was attended by 86 investigators and concentrated on many of the most promising new treatment opportunities and next-generation research technologies. RESULTS The topics of focus at the meeting included: new treatment strategies and novel agents for targeted therapies and precision medicine, new treatment strategies that may synergize with checkpoint immunotherapy, next-generation technologies that visualize tumor microenvironment (TME) and molecular pathology in situ, multi-omics and tumor heterogeneity using single cells, 3D and TME models, and the role of extracellular vesicles in cancer and their potential as biomarkers. DISCUSSION This meeting report provides a comprehensive summary of the talks and discussions held at the 2019 CHPCA Meeting, for the purpose of globally disseminating this knowledge and ultimately accelerating new treatments and diagnostics for patients with prostate cancer.
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Affiliation(s)
- Andrea K. Miyahira
- Science Department, Prostate Cancer Foundation, Santa Monica, California
| | - Adam Sharp
- Division of Clinical Studies, Institute of Cancer Research, London, UK
- Department of Medicine, The Royal Marsden NHS Foundation Trust, London, UK
| | - Leigh Ellis
- Department of Oncologic Pathology, Dana-Farber Cancer Institute, Boston, Massachusetts
- Department of Pathology, Brigham and Womenʼs Hospital, Harvard Medical School, Boston, Massachusetts
- The Broad Institute of MIT and Harvard University, Cambridge, Massachusetts
| | - Jennifer Jones
- National Cancer Institute, Center for Cancer Research, National Institutes of Health, Bethesda, Maryland
| | - Salma Kaochar
- Department of Medicine, Baylor College of Medicine, Houston, Texas
| | - H. Benjamin Larman
- Division of Immunology, Department of Pathology, The Johns Hopkins School of Medicine, Baltimore, Maryland
| | - David A. Quigley
- Helen Diller Family Comprehensive Cancer Center, University of California San Francisco, San Francisco, California
- Department of Epidemiology & Biostatistics, University of California San Francisco, San Francisco, California
| | - Huihui Ye
- Department of Pathology, University of California Los Angeles, Los Angeles, California
- Department of Urology, University of California Los Angeles, Los Angeles, California
| | - Jonathan W. Simons
- Science Department, Prostate Cancer Foundation, Santa Monica, California
| | - Kenneth J. Pienta
- Department of Oncology, Sidney Kimmel Comprehensive Cancer Center, The Johns Hopkins School of Medicine, Baltimore, Maryland
- Department of Urology, The James Buchanan Brady Urological Institute, Baltimore, Maryland
- Department of Pharmacology and Molecular Sciences, The Johns Hopkins School of Medicine, Baltimore, Maryland
| | - Howard R. Soule
- Science Department, Prostate Cancer Foundation, Santa Monica, California
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Dolgova EV, Evdokimov AN, Proskurina AS, Efremov YR, Bayborodin SI, Potter EA, Popov AA, Petruseva IO, Lavrik OI, Bogachev SS. Double-Stranded DNA Fragments Bearing Unrepairable Lesions and Their Internalization into Mouse Krebs-2 Carcinoma Cells. Nucleic Acid Ther 2019; 29:278-290. [PMID: 31194620 DOI: 10.1089/nat.2019.0786] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Murine Krebs-2 tumor-initiating stem cells are known to natively internalize extracellular double-stranded DNA fragments. Being internalized, these fragments interfere in the repair of chemically induced interstrand cross-links. In the current investigation, 756 bp polymerase chain reaction (PCR) product containing bulky photoreactive dC adduct was used as extracellular DNA. This adduct was shown to inhibit the cellular system of nucleotide excision repair while being resistant to excision by this DNA repair system. The basic parameters for this DNA probe internalization by the murine Krebs-2 tumor cells were characterized. Being incubated under regular conditions (60 min, 24°C, 500 μL of the incubation medium, in the dark), 0.35% ± 0.18% of the Krebs-2 ascites cells were shown to natively internalize modified DNA. The saturating amount of the modified DNA was detected to be 0.37 μg per 106 cells. For the similar unmodified DNA fragments, this ratio is 0.73 μg per 106 cells. Krebs-2 tumor cells were shown to be saturated internalizing either (190 ± 40) × 103 molecules of modified DNA or (1,000 ± 100) × 103 molecules of native DNA. On internalization, the fragments of DNA undergo partial and nonuniform hydrolysis of 3' ends followed by circularization. The degree of hydrolysis, assessed by sequencing of several clones with the insertion of specific PCR product, was 30-60 nucleotides.
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Affiliation(s)
- Evgeniya V Dolgova
- Laboratory of Induced Cell Processes, Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
| | - Alexey N Evdokimov
- Laboratory of Bioorganic Chemistry of Enzymes, Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
| | - Anastasia S Proskurina
- Laboratory of Induced Cell Processes, Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
| | - Yaroslav R Efremov
- Laboratory of Induced Cell Processes, Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia.,Natural Sciences Department, Novosibirsk State University, Novosibirsk, Russia
| | - Sergey I Bayborodin
- Laboratory of Induced Cell Processes, Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
| | - Ekaterina A Potter
- Laboratory of Induced Cell Processes, Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
| | - Alexey A Popov
- Laboratory of Bioorganic Chemistry of Enzymes, Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
| | - Irina O Petruseva
- Laboratory of Bioorganic Chemistry of Enzymes, Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
| | - Olga I Lavrik
- Laboratory of Bioorganic Chemistry of Enzymes, Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia.,Natural Sciences Department, Novosibirsk State University, Novosibirsk, Russia.,Department of Physical Chemistry and Biotechnology, Altai State University, Barnaul, Russia
| | - Sergey S Bogachev
- Laboratory of Induced Cell Processes, Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
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Dellino GI, Palluzzi F, Chiariello AM, Piccioni R, Bianco S, Furia L, De Conti G, Bouwman BAM, Melloni G, Guido D, Giacò L, Luzi L, Cittaro D, Faretta M, Nicodemi M, Crosetto N, Pelicci PG. Release of paused RNA polymerase II at specific loci favors DNA double-strand-break formation and promotes cancer translocations. Nat Genet 2019; 51:1011-1023. [PMID: 31110352 DOI: 10.1038/s41588-019-0421-z] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Accepted: 04/12/2019] [Indexed: 01/05/2023]
Abstract
It is not clear how spontaneous DNA double-strand breaks (DSBs) form and are processed in normal cells, and whether they predispose to cancer-associated translocations. We show that DSBs in normal mammary cells form upon release of paused RNA polymerase II (Pol II) at promoters, 5' splice sites and active enhancers, and are processed by end-joining in the absence of a canonical DNA-damage response. Logistic and causal-association models showed that Pol II pausing at long genes is the main predictor and determinant of DSBs. Damaged introns with paused Pol II-pS5, TOP2B and XRCC4 are enriched in translocation breakpoints, and map at topologically associating domain boundary-flanking regions showing high interaction frequencies with distal loci. Thus, in unperturbed growth conditions, release of paused Pol II at specific loci and chromatin territories favors DSB formation, leading to chromosomal translocations.
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Affiliation(s)
- Gaetano Ivan Dellino
- Department of Experimental Oncology, IEO, European Institute of Oncology IRCCS, Milan, Italy. .,Department of Oncology and Hemato-Oncology, University of Milan, Milan, Italy.
| | - Fernando Palluzzi
- Department of Experimental Oncology, IEO, European Institute of Oncology IRCCS, Milan, Italy.,Department of Brain and Behavioural Sciences, University of Pavia, Pavia, Italy
| | - Andrea Maria Chiariello
- Department of Physics, University of Naples Federico II, and INFN Complesso di Monte Sant'Angelo, Naples, Italy
| | - Rossana Piccioni
- Department of Experimental Oncology, IEO, European Institute of Oncology IRCCS, Milan, Italy
| | - Simona Bianco
- Department of Physics, University of Naples Federico II, and INFN Complesso di Monte Sant'Angelo, Naples, Italy
| | - Laura Furia
- Department of Experimental Oncology, IEO, European Institute of Oncology IRCCS, Milan, Italy
| | - Giulia De Conti
- Department of Experimental Oncology, IEO, European Institute of Oncology IRCCS, Milan, Italy
| | - Britta A M Bouwman
- Science for Life Laboratory, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Giorgio Melloni
- Department of Experimental Oncology, IEO, European Institute of Oncology IRCCS, Milan, Italy.,Department of Biomedical Informatics, Harvard Medical School, Boston, MA, USA
| | - Davide Guido
- Neurology, Public Health and Disability Unit, Foundation IRCCS Neurological Institute Carlo Besta, Milan, Italy
| | - Luciano Giacò
- Department of Experimental Oncology, IEO, European Institute of Oncology IRCCS, Milan, Italy
| | - Lucilla Luzi
- Department of Experimental Oncology, IEO, European Institute of Oncology IRCCS, Milan, Italy
| | - Davide Cittaro
- Center for Translational Genomics and Bioinformatics, IRCCS San Raffaele Hospital, Milan, Italy
| | - Mario Faretta
- Department of Experimental Oncology, IEO, European Institute of Oncology IRCCS, Milan, Italy
| | - Mario Nicodemi
- Department of Physics, University of Naples Federico II, and INFN Complesso di Monte Sant'Angelo, Naples, Italy.,Berlin Institute of Health, MDC-Berlin, Berlin, Germany
| | - Nicola Crosetto
- Science for Life Laboratory, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Pier Giuseppe Pelicci
- Department of Experimental Oncology, IEO, European Institute of Oncology IRCCS, Milan, Italy. .,Department of Oncology and Hemato-Oncology, University of Milan, Milan, Italy.
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25
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Rai P, Sobol RW. Mechanisms of MTH1 inhibition-induced DNA strand breaks: The slippery slope from the oxidized nucleotide pool to genotoxic damage. DNA Repair (Amst) 2019; 77:18-26. [PMID: 30852368 DOI: 10.1016/j.dnarep.2019.03.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2019] [Revised: 02/28/2019] [Accepted: 03/01/2019] [Indexed: 12/14/2022]
Abstract
Unlike normal tissues, tumor cells possess a propensity for genomic instability, resulting from elevated oxidant levels produced by oncogenic signaling and aberrant cellular metabolism. Thus, targeting mechanisms that protect cancer cells from the tumor-inhibitory consequences of their redox imbalance and spontaneous DNA-damaging events is expected to have broad-spectrum efficacy and a high therapeutic index. One critical mechanism for tumor cell protection from oxidant stress is the hydrolysis of oxidized nucleotides. Human MutT homolog 1 (MTH1), the mammalian nudix (nucleoside diphosphate X) pyrophosphatase (NUDT1), protects tumor cells from oxidative stress-induced genomic DNA damage by cleansing the nucleotide pool of oxidized purine nucleotides. Depletion or pharmacologic inhibition of MTH1 results in genomic DNA strand breaks in many cancer cells. However, the mechanisms underlying how oxidized nucleotides, thought mainly to be mutagenic rather than genotoxic, induce DNA strand breaks are largely unknown. Given the recent therapeutic interest in targeting MTH1, a better understanding of such mechanisms is crucial to its successful translation into the clinic and in identifying the molecular contexts under which its inhibition is likely to be beneficial. Here we provide a comprehensive perspective on MTH1 function and its importance in protecting genome integrity, in the context of tumor-associated oxidative stress and the mechanisms that likely lead to irreparable DNA strand breaks as a result of MTH1 inhibition.
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Affiliation(s)
- Priyamvada Rai
- Department of Medicine/Division of Medical Oncology, University of Miami Miller School of Medicine, Miami, FL, 33136, United States; Sylvester Comprehensive Cancer Center, Miami, FL, 33136, United States.
| | - Robert W Sobol
- Mitchell Cancer Institute, University of South Alabama, 1660 Springhill Avenue, Mobile, AL, 36604, United States.
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26
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Kirikovich SS, Taranov OS, Omigov VV, Potter EA, Dolgova EV, Proskurina AS, Efremov YR, Bogachev SS. Ultrastructural analysis of the Krebs-2 ascites cancer cells treated with extracellular double-stranded DNA preparation. Ultrastruct Pathol 2019; 43:56-65. [PMID: 30758240 DOI: 10.1080/01913123.2019.1575499] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Electron-microscopic analysis of the ultrastructure of the Krebs-2 carcinoma ascites cells in the first 90 min immediately after their exposure to fragmented double-stranded DNA has been performed. Morphological attributes of the treated cancer cells indicate the induction in these cells of destructive processes of presumably apoptotic type. The predominance of dystrophic-destructive changes in cells after the addition of DNA is supposed to be a consequence of the disturbance in metabolic processes caused by the experimental action.
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Affiliation(s)
- Svetlana S Kirikovich
- a Institute of Cytology and Genetics , Siberian Branch of the Russian Academy of Sciences , Novosibirsk , Russia
| | - Oleg S Taranov
- b State Research Center of Virology and Biotechnology VECTOR , Rospotrebnadzor , Novosibirsk region , Russia
| | - Vladimir V Omigov
- b State Research Center of Virology and Biotechnology VECTOR , Rospotrebnadzor , Novosibirsk region , Russia
| | - Ekaterina A Potter
- a Institute of Cytology and Genetics , Siberian Branch of the Russian Academy of Sciences , Novosibirsk , Russia
| | - Evgenia V Dolgova
- a Institute of Cytology and Genetics , Siberian Branch of the Russian Academy of Sciences , Novosibirsk , Russia
| | - Anastasia S Proskurina
- a Institute of Cytology and Genetics , Siberian Branch of the Russian Academy of Sciences , Novosibirsk , Russia
| | - Yaroslav R Efremov
- a Institute of Cytology and Genetics , Siberian Branch of the Russian Academy of Sciences , Novosibirsk , Russia.,c Department of natural sciences , Novosibirsk State University , Novosibirsk , Russia
| | - Sergey S Bogachev
- a Institute of Cytology and Genetics , Siberian Branch of the Russian Academy of Sciences , Novosibirsk , Russia
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27
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Sakaguchi K, Shiraishi K, Kodama S. High susceptibility of mouse newborns to delayed appearance of DNA double-strand breaks in neural stem/progenitor cells exposed to ionizing radiation. JOURNAL OF RADIATION RESEARCH 2018; 59:685-691. [PMID: 30165446 PMCID: PMC6251430 DOI: 10.1093/jrr/rry069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Revised: 07/18/2018] [Indexed: 06/08/2023]
Abstract
Fetal brains are known to be extremely sensitive to ionizing radiation, which can induce structural and functional defects in the developing brain. However, there is less data on the effects of radiation on newborn brains. To determine the radiation sensitivity in newborn brains, we determined the number of DNA double-strand breaks (DSBs) appearing at later stage post-irradiation in neural stem/progenitor cells (NSPCs) of mouse newborns <3 days old, and compared it with the numbers of DSBs of fetal, 1-week-neonate, 2-week-neonate, and adult mice. DSBs in the nucleus were quantified by counting the number of foci of phosphorylated histone H2AX (γ-H2AX) in NPSCs using a newly developed computer program. Then, we irradiated 14-day fetuses, newborns <3 days old, 1-week-old neonates, 2-week-old neonates, and 12-week-old adult mice with 2 Gy of X-rays. At 6-7 weeks post-irradiation, the brain tissues isolated from the mice were incubated, and DSBs in the growing neurospheres were counted using a focus-counting program. The delayed appearance of DSBs by X-irradiation was evident in NSPCs derived from newborns <3 days old, as well as in 1-week-old neonates, 2-week-old neonates and adult mice, but not 14-day fetuses, at 6-7 weeks post-irradiation. It was of particular interest that the NSPCs of newborns were 2.5-fold more susceptible than those of adults to radiation-induced delayed appearance of DSBs, indicating that newborns <3 days old are the most vulnerable to the delayed effects of radiation among the mouse groups examined.
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Affiliation(s)
- Kenta Sakaguchi
- Laboratory of Radiation Biology, Department of Biological Science, Graduate School of Science, Osaka Prefecture University, 1–2 Gakuen-cho, Naka-ku, Sakai, Osaka, Japan
- Department of Radiology, Kindai University Hospital, 377-2 Ohnohigashi, Osakasayama, Osaka, Japan
| | - Kazunori Shiraishi
- Laboratory of Radiation Biology, Department of Biological Science, Graduate School of Science, Osaka Prefecture University, 1–2 Gakuen-cho, Naka-ku, Sakai, Osaka, Japan
| | - Seiji Kodama
- Laboratory of Radiation Biology, Department of Biological Science, Graduate School of Science, Osaka Prefecture University, 1–2 Gakuen-cho, Naka-ku, Sakai, Osaka, Japan
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28
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Wangensteen KJ, Wang YJ, Dou Z, Wang AW, Mosleh-Shirazi E, Horlbeck MA, Gilbert LA, Weissman JS, Berger SL, Kaestner KH. Combinatorial genetics in liver repopulation and carcinogenesis with a in vivo CRISPR activation platform. Hepatology 2018; 68:663-676. [PMID: 29091290 PMCID: PMC5930141 DOI: 10.1002/hep.29626] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Revised: 10/09/2017] [Accepted: 10/30/2017] [Indexed: 12/12/2022]
Abstract
Clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated 9 activation (CRISPRa) systems have enabled genetic screens in cultured cell lines to discover and characterize drivers and inhibitors of cancer cell growth. We adapted this system for use in vivo to assess whether modulating endogenous gene expression levels can result in functional outcomes in the native environment of the liver. We engineered the catalytically dead CRISPR-associated 9 (dCas9)-positive mouse, cyclization recombination-inducible (Cre) CRISPRa system for cell type-specific gene activation in vivo. We tested the capacity for genetic screening in live animals by applying CRISPRa in a clinically relevant model of liver injury and repopulation. We targeted promoters of interest in regenerating hepatocytes using multiple single guide RNAs (gRNAs), and employed high-throughput sequencing to assess enrichment of gRNA sequences during liver repopulation and to link specific gRNAs to the initiation of carcinogenesis. All components of the CRISPRa system were expressed in a cell type-specific manner and activated endogenous gene expression in vivo. Multiple gRNA cassettes targeting a proto-oncogene were significantly enriched following liver repopulation, indicative of enhanced division of cells expressing the proto-oncogene. Furthermore, hepatocellular carcinomas developed containing gRNAs that activated this oncogene, indicative of cancer initiation events. Also, we employed our system for combinatorial cancer genetics in vivo as we found that while clonal hepatocellular carcinomas were dependent on the presence of the oncogene-inducing gRNAs, they were depleted for multiple gRNAs activating tumor suppressors. CONCLUSION The in vivo CRISPRa platform developed here allows for parallel and combinatorial genetic screens in live animals; this approach enables screening for drivers and suppressors of cell replication and tumor initiation. (Hepatology 2017).
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Affiliation(s)
- Kirk J. Wangensteen
- Department of Medicine, Division of Gastroenterology, University of Pennsylvania, Philadelphia, PA, 19104, USA
- Department of Genetics, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Yue J. Wang
- Department of Genetics, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Zhixun Dou
- Department of Genetics, University of Pennsylvania, Philadelphia, PA, 19104, USA
- Epigenetics Institute, Department of Cell and Developmental Biology, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Amber W. Wang
- Department of Genetics, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Elham Mosleh-Shirazi
- Department of Genetics, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Max A. Horlbeck
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA, 94158, USA
| | - Luke A. Gilbert
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA, 94158, USA
| | - Jonathan S. Weissman
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA, 94158, USA
| | - Shelley L. Berger
- Department of Genetics, University of Pennsylvania, Philadelphia, PA, 19104, USA
- Epigenetics Institute, Department of Cell and Developmental Biology, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Klaus H. Kaestner
- Department of Genetics, University of Pennsylvania, Philadelphia, PA, 19104, USA
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Yang C, Bromma K, Sung W, Schuemann J, Chithrani D. Determining the Radiation Enhancement Effects of Gold Nanoparticles in Cells in a Combined Treatment with Cisplatin and Radiation at Therapeutic Megavoltage Energies. Cancers (Basel) 2018; 10:cancers10050150. [PMID: 29786642 PMCID: PMC5977123 DOI: 10.3390/cancers10050150] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Revised: 05/12/2018] [Accepted: 05/14/2018] [Indexed: 11/16/2022] Open
Abstract
Combined use of chemotherapy and radiation therapy is commonly used in cancer treatment, but the toxic effects on normal tissue are a major limitation. This study assesses the potential to improve radiation therapy when combining gold nanoparticle (GNP) mediated radiation sensitization with chemoradiation compared to chemoradiation alone. Incorporation of GNPs with 2 Gy, 6 MV (megavoltage) radiation resulted in a 19 ± 6% decrease in survival of MDA-MB-231 cells. Monte-Carlo simulations were performed to assess dosimetric differences in the presence of GNPs in radiation. The results show that physics dosimetry represents a small fraction of the observed effect. The survival fraction of the cells exposed to GNPs, cisplatin, and radiation was 0.16 ± 0.007, while cells treated with cisplatin and radiation only was 0.23 ± 0.011. The presence of GNPs resulted in a 30 ± 6% decrease in the survival, having an additive effect. The concentration of the GNPs and free drug used for this study was 0.3 and 435 nM, respectively. These concentrations are relatively lower and achievable in an in vivo setting. Hence, the results of our study would accelerate the incorporation of GNP-mediated chemoradiation into current cancer therapeutic protocols in the near future.
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Affiliation(s)
- Celina Yang
- Department of Biomedical Physics, Ryerson University, Toronto, ON M5B 2K3, Canada.
| | - Kyle Bromma
- Department of Physics and Astronomy, University of Victoria, Victoria, BC V8P 5C2, Canada.
| | - Wonmo Sung
- Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA.
| | - Jan Schuemann
- Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA.
| | - Devika Chithrani
- Department of Biomedical Physics, Ryerson University, Toronto, ON M5B 2K3, Canada.
- Department of Physics and Astronomy, University of Victoria, Victoria, BC V8P 5C2, Canada.
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30
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Abramenkovs A, Stenerlöw B. Measurement of DNA-Dependent Protein Kinase Phosphorylation Using Flow Cytometry Provides a Reliable Estimate of DNA Repair Capacity. Radiat Res 2017; 188:597-604. [PMID: 28952912 DOI: 10.1667/rr14693.1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Uncontrolled generation of DNA double-strand breaks (DSBs) in cells is regarded as a highly toxic event that threatens cell survival. Radiation-induced DNA DSBs are commonly measured by pulsed-field gel electrophoresis, microscopic evaluation of accumulating DNA damage response proteins (e.g., 53BP1 or γ-H2AX) or flow cytometric analysis of γ-H2AX. The advantage of flow cytometric analysis is that DSB formation and repair can be studied in relationship to cell cycle phase or expression of other proteins. However, γ-H2AX is not able to monitor repair kinetics within the first 60 min postirradiation, a period when most DSBs undergo repair. A key protein in non-homologous end joining repair is the catalytic subunit of DNA-dependent protein kinase. Among several phosphorylation sites of DNA-dependent protein kinase, the threonine at position 2609 (T2609), which is phosphorylated by ataxia telangiectasia mutated (ATM) or DNA-dependent protein kinase catalytic subunit itself, activates the end processing of DSB. Using flow cytometry, we show here that phosphorylation at T2609 is faster in response to DSBs than γ-H2AX. Furthermore, flow cytometric analysis of T2609 resulted in a better representation of fast repair kinetics than analysis of γ-H2AX. In cells with reduced ligase IV activity, and wild-type cells where DNA-dependent protein kinase activity was inhibited, the reduced DSB repair capacity was observed by T2609 evaluation using flow cytometry. In conclusion, flow cytometric evaluation of DNA-dependent protein kinase T2609 can be used as a marker for early DSB repair and gives a better representation of early repair events than analysis of γ-H2AX.
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Affiliation(s)
- Andris Abramenkovs
- Department of Immunology, Genetics and Pathology, Rudbeck Laboratory, Uppsala University, SE-751 85 Uppsala, Sweden
| | - Bo Stenerlöw
- Department of Immunology, Genetics and Pathology, Rudbeck Laboratory, Uppsala University, SE-751 85 Uppsala, Sweden
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31
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Samaranayake GJ, Huynh M, Rai P. MTH1 as a Chemotherapeutic Target: The Elephant in the Room. Cancers (Basel) 2017; 9:cancers9050047. [PMID: 28481306 PMCID: PMC5447957 DOI: 10.3390/cancers9050047] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2017] [Revised: 04/29/2017] [Accepted: 04/29/2017] [Indexed: 12/26/2022] Open
Abstract
Many tumors sustain elevated levels of reactive oxygen species (ROS), which drive oncogenic signaling. However, ROS can also trigger anti-tumor responses, such as cell death or senescence, through induction of oxidative stress and concomitant DNA damage. To circumvent the adverse consequences of elevated ROS levels, many tumors develop adaptive responses, such as enhanced redox-protective or oxidatively-generated damage repair pathways. Targeting these enhanced oxidative stress-protective mechanisms is likely to be both therapeutically effective and highly specific to cancer, as normal cells are less reliant on such mechanisms. In this review, we discuss one such stress-protective protein human MutT Homolog1 (MTH1), an enzyme that eliminates 8-oxo-7,8-dihydro-2’-deoxyguanosine triphosphate (8-oxodGTP) through its pyrophosphatase activity, and is found to be elevated in many cancers. Our studies, and subsequently those of others, identified MTH1 inhibition as an effective tumor-suppressive strategy. However, recent studies with the first wave of MTH1 inhibitors have produced conflicting results regarding their cytotoxicity in cancer cells and have led to questions regarding the validity of MTH1 as a chemotherapeutic target. To address the proverbial "elephant in the room" as to whether MTH1 is a bona fide chemotherapeutic target, we provide an overview of MTH1 function in the context of tumor biology, summarize the current literature on MTH1 inhibitors, and discuss the molecular contexts likely required for its efficacy as a therapeutic target.
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Affiliation(s)
- Govindi J Samaranayake
- Department of Medicine/Division of Hematology and Oncology, University of Miami Miller School of Medicine, Miami, FL 33136, USA.
- Sheila and David Fuente Graduate Program in Cancer Biology, University of Miami, Miami, FL 33136, USA.
| | - Mai Huynh
- Department of Medicine/Division of Hematology and Oncology, University of Miami Miller School of Medicine, Miami, FL 33136, USA.
- College of Arts and Sciences, University of Miami, Coral Gables, FL 33146, USA.
| | - Priyamvada Rai
- Department of Medicine/Division of Hematology and Oncology, University of Miami Miller School of Medicine, Miami, FL 33136, USA.
- Sylvester Comprehensive Cancer Center, Miami, FL 33136, USA.
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32
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Abu-Zhayia ER, Khoury-Haddad H, Guttmann-Raviv N, Serruya R, Jarrous N, Ayoub N. A role of human RNase P subunits, Rpp29 and Rpp21, in homology directed-repair of double-strand breaks. Sci Rep 2017; 7:1002. [PMID: 28432356 PMCID: PMC5430778 DOI: 10.1038/s41598-017-01185-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Accepted: 03/22/2017] [Indexed: 12/21/2022] Open
Abstract
DNA damage response (DDR) is needed to repair damaged DNA for genomic integrity preservation. Defective DDR causes accumulation of deleterious mutations and DNA lesions that can lead to genomic instabilities and carcinogenesis. Identifying new players in the DDR, therefore, is essential to advance the understanding of the molecular mechanisms by which cells keep their genetic material intact. Here, we show that the core protein subunits Rpp29 and Rpp21 of human RNase P complex are implicated in DDR. We demonstrate that Rpp29 and Rpp21 depletion impairs double-strand break (DSB) repair by homology-directed repair (HDR), but has no deleterious effect on the integrity of non-homologous end joining. We also demonstrate that Rpp29 and Rpp21, but not Rpp14, Rpp25 and Rpp38, are rapidly and transiently recruited to laser-microirradiated sites. Rpp29 and Rpp21 bind poly ADP-ribose moieties and are recruited to DNA damage sites in a PARP1-dependent manner. Remarkably, depletion of the catalytic H1 RNA subunit diminishes their recruitment to laser-microirradiated regions. Moreover, RNase P activity is augmented after DNA damage in a PARP1-dependent manner. Altogether, our results describe a previously unrecognized function of the RNase P subunits, Rpp29 and Rpp21, in fine-tuning HDR of DSBs.
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Affiliation(s)
- Enas R Abu-Zhayia
- Department of Biology, Technion - Israel Institute of Technology, Haifa, 3200003, Israel
| | - Hanan Khoury-Haddad
- Department of Biology, Technion - Israel Institute of Technology, Haifa, 3200003, Israel
| | - Noga Guttmann-Raviv
- Department of Biology, Technion - Israel Institute of Technology, Haifa, 3200003, Israel
| | - Raphael Serruya
- Department of Microbiology and Molecular Genetics, IMRIC, The Hebrew University-Hadassah Medical School, 91120, Jerusalem, Israel
| | - Nayef Jarrous
- Department of Microbiology and Molecular Genetics, IMRIC, The Hebrew University-Hadassah Medical School, 91120, Jerusalem, Israel.
| | - Nabieh Ayoub
- Department of Biology, Technion - Israel Institute of Technology, Haifa, 3200003, Israel.
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33
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Understanding the Effectiveness of Natural Compound Mixtures in Cancer through Their Molecular Mode of Action. Int J Mol Sci 2017; 18:ijms18030656. [PMID: 28304343 PMCID: PMC5372668 DOI: 10.3390/ijms18030656] [Citation(s) in RCA: 164] [Impact Index Per Article: 23.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Revised: 03/13/2017] [Accepted: 03/15/2017] [Indexed: 12/19/2022] Open
Abstract
Many approaches to cancer management are often ineffective due to adverse reactions, drug resistance, or inadequate target specificity of single anti-cancer agents. In contrast, a combinatorial approach with the application of two or more anti-cancer agents at their respective effective dosages can achieve a synergistic effect that boosts cytotoxicity to cancer cells. In cancer, aberrant apoptotic pathways allow cells that should be killed to survive with genetic abnormalities, leading to cancer progression. Mutations in apoptotic mechanism arising during the treatment of cancer through cancer progression can consequently lead to chemoresistance. Natural compound mixtures that are believed to have multiple specific targets with minimal acceptable side-effects are now of interest to many researchers due to their cytotoxic and chemosensitizing activities. Synergistic interactions within a drug mixture enhance the search for potential molecular targets in cancer cells. Nonetheless, biased/flawed scientific evidence from natural products can suggest false positive therapeutic benefits during drug screening. In this review, we have taken these factors into consideration when discussing the evidence for these compounds and their synergistic therapeutic benefits in cancer. While there is limited evidence for clinical efficacy for these mixtures, in vitro data suggest that these preparations merit further investigation, both in vitro and in vivo.
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Saini KS, Hamidullah, Ashraf R, Mandalapu D, Das S, Siddiqui MQ, Dwivedi S, Sarkar J, Sharma VL, Konwar R. New orally active DNA minor groove binding small molecule CT-1 acts against breast cancer by targeting tumor DNA damage leading to p53-dependent apoptosis. Mol Carcinog 2016; 56:1266-1280. [DOI: 10.1002/mc.22588] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Revised: 10/31/2016] [Accepted: 11/02/2016] [Indexed: 11/06/2022]
Affiliation(s)
- Karan Singh Saini
- Division of Endocrinology; CSIR-Central Drug Research Institute; Lucknow India
| | - Hamidullah
- Division of Endocrinology; CSIR-Central Drug Research Institute; Lucknow India
| | - Raghib Ashraf
- Division of Biochemistry; CSIR-Central Drug Research Institute; Lucknow India
| | - Dhanaraju Mandalapu
- Medicinal & Process Chemistry Division; CSIR-Central Drug Research Institute; Lucknow India
| | - Sharmistha Das
- Division of Endocrinology; CSIR-Central Drug Research Institute; Lucknow India
| | - Mohd Quadir Siddiqui
- Advanced Centre for Treatment; Research and Education in Cancer, Kharghar, Navi Mumbai; Maharashtra India
| | - Sonam Dwivedi
- Division of Endocrinology; CSIR-Central Drug Research Institute; Lucknow India
| | - Jayanta Sarkar
- Division of Biochemistry; CSIR-Central Drug Research Institute; Lucknow India
- Academy of Scientific and Innovative Research (AcSIR); New Delhi India
| | - Vishnu Lal Sharma
- Medicinal & Process Chemistry Division; CSIR-Central Drug Research Institute; Lucknow India
- Academy of Scientific and Innovative Research (AcSIR); New Delhi India
| | - Rituraj Konwar
- Division of Endocrinology; CSIR-Central Drug Research Institute; Lucknow India
- Academy of Scientific and Innovative Research (AcSIR); New Delhi India
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Dolgova EV, Shevela EY, Tyrinova TV, Minkevich AM, Proskurina AS, Potter EA, Orishchenko KE, Zavjalov EL, Bayborodin SI, Nikolin VP, Popova NA, Pronkina NV, Ostanin AA, Chernykh ER, Bogachev SS. Nonadherent Spheres With Multiple Myeloma Surface Markers Contain Cells that Contribute to Sphere Formation and Are Capable of Internalizing Extracellular Double-Stranded DNA. CLINICAL LYMPHOMA MYELOMA & LEUKEMIA 2016; 16:563-576. [PMID: 27431933 DOI: 10.1016/j.clml.2016.06.014] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Revised: 05/20/2016] [Accepted: 06/01/2016] [Indexed: 11/18/2022]
Abstract
BACKGROUND The most prominent features of cancer stem cells are asymmetric cell division, tumorigenicity, and clonogenicity. Recently one more feature of poorly differentiated cell types of various origin, including cancer stem cells, has been described. Namely, these cells can internalize extracellular DNA natively, without additional transfection procedures. PATIENTS AND METHODS Using our approach to trace internalization of a TAMRA (carboxy tetramethyl-rhodamine [fluorescent dye])-DNA labeled probe by poorly differentiated cell types, we isolated and characterized the cells from free-floating spheres derived from the bone marrow clonogenic aspirate of a multiple myeloma patient. RESULTS Nonadherent spheres display a B-cell phenotype (CD73/CD20+/CD45+/CD19dim). Further, free-floating spheres contain 1% to 3% cells with a clonogenic potential, and these cells display a marker of poorly differentiated cell types (TAMRA+). Upon association with a group of ∼ 10 free-floating TAMRA- cells, this peculiar cell type forms a sphere-forming cluster that initiates secondary aggregation of cells into a spheric structure. TAMRA+ and TAMRA- cells secrete distinct sets of cytokines indicative of the paracrine regulation. Grafting experiments of intact whole spheres versus cell suspensions prepared from dispersed spheres indicate that successful engraftment only occurs in the former case. CONCLUSION Nonadherent 3-D cell colonies (spheres) encompass B cells with CD73/CD20+/CD45+/CD19dim phenotype, as well as double-stranded DNA-internalizing cells. The latter cell type appears to function as a sphere-forming center. Different cells in the spheres communicate with each other by secreting specific sets of cytokines. For successful engraftment and tumor growth in mice, intact spheres containing ∼ 106 cells must be used.
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Affiliation(s)
- Evgeniya V Dolgova
- Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Medical Sciences, Novosibirsk, Russia
| | - Ekaterina Ya Shevela
- Institute of Clinical Immunology, Siberian Branch of the Russian Academy of Medical Sciences, Novosibirsk, Russia
| | - Tamara V Tyrinova
- Institute of Clinical Immunology, Siberian Branch of the Russian Academy of Medical Sciences, Novosibirsk, Russia
| | - Alexandra M Minkevich
- Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Medical Sciences, Novosibirsk, Russia
| | - Anastasia S Proskurina
- Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Medical Sciences, Novosibirsk, Russia
| | - Ekaterina A Potter
- Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Medical Sciences, Novosibirsk, Russia
| | - Konstantin E Orishchenko
- Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Medical Sciences, Novosibirsk, Russia
| | - Evgeniy L Zavjalov
- Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Medical Sciences, Novosibirsk, Russia
| | - Sergey I Bayborodin
- Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Medical Sciences, Novosibirsk, Russia
| | - Valeriy P Nikolin
- Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Medical Sciences, Novosibirsk, Russia
| | - Nelly A Popova
- Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Medical Sciences, Novosibirsk, Russia
| | - Natalia V Pronkina
- Institute of Clinical Immunology, Siberian Branch of the Russian Academy of Medical Sciences, Novosibirsk, Russia
| | - Alexandr A Ostanin
- Institute of Clinical Immunology, Siberian Branch of the Russian Academy of Medical Sciences, Novosibirsk, Russia
| | - Elena R Chernykh
- Institute of Clinical Immunology, Siberian Branch of the Russian Academy of Medical Sciences, Novosibirsk, Russia
| | - Sergey S Bogachev
- Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Medical Sciences, Novosibirsk, Russia.
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Gilchrist GC, Tscherner A, Nalpathamkalam T, Merico D, LaMarre J. MicroRNA Expression during Bovine Oocyte Maturation and Fertilization. Int J Mol Sci 2016; 17:396. [PMID: 26999121 PMCID: PMC4813251 DOI: 10.3390/ijms17030396] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Revised: 03/03/2016] [Accepted: 03/09/2016] [Indexed: 01/09/2023] Open
Abstract
Successful fertilization and subsequent embryo development rely on complex molecular processes starting with the development of oocyte competence through maturation. MicroRNAs (miRNAs) are small non-coding RNA molecules that function as gene regulators in many biological systems, including the oocyte and embryo. In order to further explore the roles of miRNAs in oocyte maturation, we employed small RNA sequencing as a screening tool to identify and characterize miRNA populations present in pools of bovine germinal vesicle (GV) oocytes, metaphase II (MII) oocytes, and presumptive zygotes (PZ). Each stage contained a defined miRNA population, some of which showed stable expression while others showed progressive changes between stages that were subsequently confirmed by quantitative reverse transcription polymerase chain reaction (RT-PCR). Bta-miR-155, bta-miR-222, bta-miR-21, bta-let-7d, bta-let-7i, and bta-miR-190a were among the statistically significant differentially expressed miRNAs (p < 0.05). To determine whether changes in specific primary miRNA (pri-miRNA) transcripts were responsible for the observed miRNA changes, we evaluated pri-miR-155, -222 and let-7d expression. Pri-miR-155 and -222 were not detected in GV oocytes but pri-miR-155 was present in MII oocytes, indicating transcription during maturation. In contrast, levels of pri-let-7d decreased during maturation, suggesting that the observed increase in let-7d expression was likely due to processing of the primary transcript. This study demonstrates that both dynamic and stable populations of miRNAs are present in bovine oocytes and zygotes and extend previous studies supporting the importance of the small RNA landscape in the maturing bovine oocyte and early embryo.
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Affiliation(s)
- Graham C Gilchrist
- Department of Biomedical Sciences, University of Guelph, Guelph, ON N1G 2W1, Canada.
| | - Allison Tscherner
- Department of Biomedical Sciences, University of Guelph, Guelph, ON N1G 2W1, Canada.
| | - Thomas Nalpathamkalam
- Program in Genetics and Genome Biology, The Centre for Applied Genomics, The Hospital for Sick Children, Toronto, ON M5G 0A4, Canada.
| | - Daniele Merico
- Program in Genetics and Genome Biology, The Centre for Applied Genomics, The Hospital for Sick Children, Toronto, ON M5G 0A4, Canada.
| | - Jonathan LaMarre
- Department of Biomedical Sciences, University of Guelph, Guelph, ON N1G 2W1, Canada.
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Du D, Qi LS. CRISPR Technology for Genome Activation and Repression in Mammalian Cells. Cold Spring Harb Protoc 2016; 2016:pdb.prot090175. [PMID: 26729910 DOI: 10.1101/pdb.prot090175] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Targeted modulation of transcription is necessary for understanding complex gene networks and has great potential for medical and industrial applications. CRISPR is emerging as a powerful system for targeted genome activation and repression, in addition to its use in genome editing. This protocol describes how to design, construct, and experimentally validate the function of sequence-specific single guide RNAs (sgRNAs) for sequence-specific repression (CRISPRi) or activation (CRISPRa) of transcription in mammalian cells. In this technology, the CRISPR-associated protein Cas9 is catalytically deactivated (dCas9) to provide a general platform for RNA-guided DNA targeting of any locus in the genome. Fusion of dCas9 to effector domains with distinct regulatory functions enables stable and efficient transcriptional repression or activation in mammalian cells. Delivery of multiple sgRNAs further enables activation or repression of multiple genes. By using scaffold RNAs (scRNAs), different effectors can be recruited to different genes for simultaneous activation of some and repression of others. The CRISPRi and CRISPRa methods provide powerful tools for sequence-specific control of gene expression on a genome-wide scale to aid understanding gene functions and for engineering genetic regulatory systems.
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Affiliation(s)
- Dan Du
- Department of Bioengineering, Stanford University, Stanford, California 94305
| | - Lei S Qi
- Department of Bioengineering, Stanford University, Stanford, California 94305; Department of Chemical and Systems Biology, Stanford University, Stanford, California 94305; ChEM-H; Stanford University, Stanford, California 94305
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Dynamics of P53 in response to DNA damage: Mathematical modeling and perspective. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2015; 119:175-82. [DOI: 10.1016/j.pbiomolbio.2015.08.017] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2015] [Accepted: 08/12/2015] [Indexed: 12/21/2022]
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Alyamkina EA, Nikolin VP, Popova NA, Minkevich AM, Kozel AV, Dolgova EV, Efremov YR, Bayborodin SI, Andrushkevich OM, Taranov OS, Omigov VV, Rogachev VA, Proskurina AS, Vereschagin EI, Kiseleva EV, Zhukova MV, Ostanin AA, Chernykh ER, Bogachev SS, Shurdov MA. Combination of cyclophosphamide and double-stranded DNA demonstrates synergistic toxicity against established xenografts. Cancer Cell Int 2015; 15:32. [PMID: 25798073 PMCID: PMC4369063 DOI: 10.1186/s12935-015-0180-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2014] [Accepted: 02/24/2015] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Extracellular double-stranded DNA participates in various processes in an organism. Here we report the suppressive effects of fragmented human double-stranded DNA along or in combination with cyclophosphamide on solid and ascites grafts of mouse Krebs-2 tumor cells and DNA preparation on human breast adenocarcinoma cell line MCF-7. METHODS Apoptosis and necrosis were assayed by electrophoretic analysis (DNA nucleosomal fragmentation) and by measurements of LDH levels in ascitic fluid, respectively. DNA internalization into MCF-7 was analyzed by flow cytometry and fluorescence microscopy. RESULTS Direct cytotoxic activity of double-stranded DNA (along or in combination with cyclophosphamide) on a solid transplant was demonstrated. This resulted in delayed solid tumor proliferation and partial tumor lysis due to necrosis of the tumor and adjacent tissues. In the case of ascites form of tumor, extensive apoptosis and secondary necrosis were observed. Similarly, MCF-7 cells showed induction of massive apoptosis (up to 45%) as a result of treatments with double-stranded DNA preparation. CONCLUSIONS Double-stranded DNA (along or in combination with cyclophosphamide) induces massive apoptosis of Krebs-2 ascite cells and MCF-7 cell line (DNA only). In treated mice it reduces the integrity of gut wall cells and contributes to the development of systemic inflammatory reaction.
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Affiliation(s)
- Ekaterina A Alyamkina
- />Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, 10 Lavrentieva ave, 630090 Novosibirsk, Russia
| | - Valeriy P Nikolin
- />Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, 10 Lavrentieva ave, 630090 Novosibirsk, Russia
| | - Nelly A Popova
- />Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, 10 Lavrentieva ave, 630090 Novosibirsk, Russia
- />Novosibirsk State University, Novosibirsk, 630090 Russia
| | - Alexandra M Minkevich
- />Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, 10 Lavrentieva ave, 630090 Novosibirsk, Russia
| | - Artem V Kozel
- />Novosibirsk State University, Novosibirsk, 630090 Russia
| | - Evgenia V Dolgova
- />Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, 10 Lavrentieva ave, 630090 Novosibirsk, Russia
| | - Yaroslav R Efremov
- />Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, 10 Lavrentieva ave, 630090 Novosibirsk, Russia
- />Novosibirsk State University, Novosibirsk, 630090 Russia
| | - Sergey I Bayborodin
- />Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, 10 Lavrentieva ave, 630090 Novosibirsk, Russia
- />Novosibirsk State University, Novosibirsk, 630090 Russia
| | - Oleg M Andrushkevich
- />Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, 10 Lavrentieva ave, 630090 Novosibirsk, Russia
- />Novosibirsk State University, Novosibirsk, 630090 Russia
| | - Oleg S Taranov
- />The State Research Center of Virology and Biotechnology VECTOR, Koltsovo, Novosibirsk region 630559 Russia
| | - Vladimir V Omigov
- />The State Research Center of Virology and Biotechnology VECTOR, Koltsovo, Novosibirsk region 630559 Russia
| | - Vladimir A Rogachev
- />Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, 10 Lavrentieva ave, 630090 Novosibirsk, Russia
| | - Anastasia S Proskurina
- />Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, 10 Lavrentieva ave, 630090 Novosibirsk, Russia
| | | | - Elena V Kiseleva
- />Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, 10 Lavrentieva ave, 630090 Novosibirsk, Russia
| | - Maria V Zhukova
- />Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, 10 Lavrentieva ave, 630090 Novosibirsk, Russia
| | - Alexandr A Ostanin
- />Institute of Clinical Immunology, Siberian Branch of the Russian Academy of Medical Sciences, Novosibirsk, 630099 Russia
| | - Elena R Chernykh
- />Institute of Clinical Immunology, Siberian Branch of the Russian Academy of Medical Sciences, Novosibirsk, 630099 Russia
| | - Sergey S Bogachev
- />Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, 10 Lavrentieva ave, 630090 Novosibirsk, Russia
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Khoury-Haddad H, Nadar-Ponniah PT, Awwad S, Ayoub N. The emerging role of lysine demethylases in DNA damage response: dissecting the recruitment mode of KDM4D/JMJD2D to DNA damage sites. Cell Cycle 2015; 14:950-8. [PMID: 25714495 PMCID: PMC4614868 DOI: 10.1080/15384101.2015.1014147] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Revised: 01/26/2015] [Accepted: 01/27/2015] [Indexed: 02/06/2023] Open
Abstract
KDM4D is a lysine demethylase that removes tri- and di- methylated residues from H3K9 and is involved in transcriptional regulation and carcinogenesis. We recently showed that KDM4D is recruited to DNA damage sites in a PARP1-dependent manner and facilitates double-strand break repair in human cells. Moreover, we demonstrated that KDM4D is an RNA binding protein and mapped its RNA-binding motifs. Interestingly, KDM4D-RNA interaction is essential for its localization on chromatin and subsequently for efficient demethylation of its histone substrate H3K9me3. Here, we provide new data that shed mechanistic insights into KDM4D accumulation at DNA damage sites. We show for the first time that KDM4D binds poly(ADP-ribose) (PAR) in vitro via its C-terminal region. In addition, we demonstrate that KDM4D-RNA interaction is required for KDM4D accumulation at DNA breakage sites. Finally, we discuss the recruitment mode and the biological functions of additional lysine demethylases including KDM4B, KDM5B, JMJD1C, and LSD1 in DNA damage response.
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Affiliation(s)
| | | | - Samah Awwad
- Department of Biology; Israel Institute of Technology; Haifa, Israel
| | - Nabieh Ayoub
- Department of Biology; Israel Institute of Technology; Haifa, Israel
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Chong KH, Samarasinghe S, Kulasiri D. Mathematical modelling of p53 basal dynamics and DNA damage response. Math Biosci 2015; 259:27-42. [DOI: 10.1016/j.mbs.2014.10.010] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Revised: 10/23/2014] [Accepted: 10/31/2014] [Indexed: 02/06/2023]
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PARRA EDUARDO, GUTIÉRREZ LUIS, FERREIRA JORGE. Inhibition of basal JNK activity by small interfering RNAs enhances cisplatin sensitivity and decreases DNA repair in T98G glioblastoma cells. Oncol Rep 2014; 33:413-8. [DOI: 10.3892/or.2014.3570] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2014] [Accepted: 09/22/2014] [Indexed: 11/05/2022] Open
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Gilbert LA, Horlbeck MA, Adamson B, Villalta JE, Chen Y, Whitehead EH, Guimaraes C, Panning B, Ploegh HL, Bassik MC, Qi LS, Kampmann M, Weissman JS. Genome-Scale CRISPR-Mediated Control of Gene Repression and Activation. Cell 2014; 159:647-61. [PMID: 25307932 PMCID: PMC4253859 DOI: 10.1016/j.cell.2014.09.029] [Citation(s) in RCA: 1736] [Impact Index Per Article: 173.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Revised: 09/03/2014] [Accepted: 09/16/2014] [Indexed: 12/28/2022]
Abstract
While the catalog of mammalian transcripts and their expression levels in different cell types and disease states is rapidly expanding, our understanding of transcript function lags behind. We present a robust technology enabling systematic investigation of the cellular consequences of repressing or inducing individual transcripts. We identify rules for specific targeting of transcriptional repressors (CRISPRi), typically achieving 90%-99% knockdown with minimal off-target effects, and activators (CRISPRa) to endogenous genes via endonuclease-deficient Cas9. Together they enable modulation of gene expression over a ∼1,000-fold range. Using these rules, we construct genome-scale CRISPRi and CRISPRa libraries, each of which we validate with two pooled screens. Growth-based screens identify essential genes, tumor suppressors, and regulators of differentiation. Screens for sensitivity to a cholera-diphtheria toxin provide broad insights into the mechanisms of pathogen entry, retrotranslocation and toxicity. Our results establish CRISPRi and CRISPRa as powerful tools that provide rich and complementary information for mapping complex pathways.
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Affiliation(s)
- Luke A Gilbert
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA; Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94158, USA; California Institute for Quantitative Biomedical Research, San Francisco, CA 94158, USA; Center for RNA Systems Biology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Max A Horlbeck
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA; Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94158, USA; California Institute for Quantitative Biomedical Research, San Francisco, CA 94158, USA; Center for RNA Systems Biology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Britt Adamson
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA; Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94158, USA; California Institute for Quantitative Biomedical Research, San Francisco, CA 94158, USA; Center for RNA Systems Biology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Jacqueline E Villalta
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA; Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94158, USA; California Institute for Quantitative Biomedical Research, San Francisco, CA 94158, USA; Center for RNA Systems Biology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Yuwen Chen
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA; Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94158, USA; California Institute for Quantitative Biomedical Research, San Francisco, CA 94158, USA; Center for RNA Systems Biology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Evan H Whitehead
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA; California Institute for Quantitative Biomedical Research, San Francisco, CA 94158, USA; Center for Systems and Synthetic Biology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Carla Guimaraes
- Department of Biology, Whitehead Institute for Biomedical Research and Massachusetts Institute of Technology, Cambridge, MA 02142, USA
| | - Barbara Panning
- Department of Biochemistry and Biophysics University of California, San Francisco, San Francisco, CA 94158, USA
| | - Hidde L Ploegh
- Department of Biology, Whitehead Institute for Biomedical Research and Massachusetts Institute of Technology, Cambridge, MA 02142, USA
| | - Michael C Bassik
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA; Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94158, USA; California Institute for Quantitative Biomedical Research, San Francisco, CA 94158, USA; Center for RNA Systems Biology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Lei S Qi
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA; California Institute for Quantitative Biomedical Research, San Francisco, CA 94158, USA; Center for Systems and Synthetic Biology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Martin Kampmann
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA; Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94158, USA; California Institute for Quantitative Biomedical Research, San Francisco, CA 94158, USA; Center for RNA Systems Biology, University of California, San Francisco, San Francisco, CA 94158, USA.
| | - Jonathan S Weissman
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA; Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94158, USA; California Institute for Quantitative Biomedical Research, San Francisco, CA 94158, USA; Center for RNA Systems Biology, University of California, San Francisco, San Francisco, CA 94158, USA.
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Kalifa L, Gewandter JS, Staversky RJ, Sia EA, Brookes PS, O'Reilly MA. DNA double-strand breaks activate ATM independent of mitochondrial dysfunction in A549 cells. Free Radic Biol Med 2014; 75:30-9. [PMID: 25048973 PMCID: PMC4171189 DOI: 10.1016/j.freeradbiomed.2014.07.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2014] [Revised: 07/07/2014] [Accepted: 07/08/2014] [Indexed: 10/25/2022]
Abstract
Excessive nuclear or mitochondrial DNA damage can lead to mitochondrial dysfunction, decreased energy production, and increased generation of reactive oxygen species (ROS). Although numerous cell signaling pathways are activated when cells are injured, the ataxia telangiectasia mutant (ATM) protein has emerged as a major regulator of the response to both mitochondrial dysfunction and nuclear DNA double-strand breaks (DSBs). Because mitochondrial dysfunction is often a response to excessive DNA damage, it has been difficult to determine whether nuclear and/or mitochondrial DNA DSBs activate ATM independent of mitochondrial dysfunction. In this study, mitochondrial and nuclear DNA DSBs were generated in the A549 human lung adenocarcinoma cell line by infecting with retroviruses expressing the restriction endonuclease PstI fused to a mitochondrial targeting sequence (MTS) or nuclear localization sequence (NLS) and a hemagglutinin antigen epitope tag (HA). Expression of MTS-PstI-HA or NLS-PstI-HA activated the DNA damage response defined by phosphorylation of ATM, the tumor suppressor protein p53 (TP53), KRAB-associated protein (KAP)-1, and structural maintenance of chromosomes (SMC)-1. Phosphorylated ATM and SMC1 were detected in nuclear fractions, whereas phosphorylated TP53 and KAP1 were detected in both mitochondrial and nuclear fractions. PstI also enhanced expression of the cyclin-dependent kinase inhibitor p21 and inhibited cell growth. This response to DNA damage occurred in the absence of detectable mitochondrial dysfunction and excess production of ROS. These findings reveal that DNA DSBs are sufficient to activate ATM independent of mitochondrial dysfunction and suggest that the activated form of ATM and some of its substrates are restricted to the nuclear compartment, regardless of the site of DNA damage.
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Affiliation(s)
- Lidza Kalifa
- Department of Environmental Medicine, The University of Rochester, Rochester, NY 14642, USA
| | - Jennifer S Gewandter
- Department of Anesthesiology, The University of Rochester, Rochester, NY 14642, USA
| | - Rhonda J Staversky
- Department of Pediatrics, The University of Rochester, Rochester, NY 14642, USA
| | - Elaine A Sia
- Department of Biology, The University of Rochester, Rochester, NY 14642, USA
| | - Paul S Brookes
- Department of Anesthesiology, The University of Rochester, Rochester, NY 14642, USA
| | - Michael A O'Reilly
- Department of Pediatrics, The University of Rochester, Rochester, NY 14642, USA.
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Investigation of oscillation accumulation triggered genetic switch in gene regulatory networks. J Theor Biol 2014; 353:61-6. [PMID: 24650938 DOI: 10.1016/j.jtbi.2014.03.017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2013] [Revised: 02/09/2014] [Accepted: 03/10/2014] [Indexed: 11/22/2022]
Abstract
Genetic oscillator motifs and genetic switch motifs are blocks of biochemical reaction networks, which are involved in the regulation of rhythms, cell cycle progression, signal processing and cell fate decision. These motifs often interact to constitute complex signal processing systems. There widely exists the oscillation accumulation triggered mechanism in gene regulatory networks, i.e., an oscillator promotes the accumulation of a signaling protein over a threshold value, and activates a switch. The structure can be fund in some important biological function switches, such as apoptosis and DNA repair. We propose the structure as an oscillation accumulation triggered genetic switch (OATGS). Through mathematical modeling and analysis, results show the OATGS with features of robustness to noise and triggered mode. In addition, we show the existence of OATGS features and triggered manner in p53 gene regulatory networks, and explain some of the p53 regulation process, such as counting mechanism and pulse shape. We speculate that OATGS with oscillation accumulation triggered manner is a new important biological function switch.
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p53 requires the stress sensor USF1 to direct appropriate cell fate decision. PLoS Genet 2014; 10:e1004309. [PMID: 24831529 PMCID: PMC4022457 DOI: 10.1371/journal.pgen.1004309] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2013] [Accepted: 03/02/2014] [Indexed: 11/19/2022] Open
Abstract
Genomic instability is a major hallmark of cancer. To maintain genomic integrity, cells are equipped with dedicated sensors to monitor DNA repair or to force damaged cells into death programs. The tumor suppressor p53 is central in this process. Here, we report that the ubiquitous transcription factor Upstream Stimulatory factor 1 (USF1) coordinates p53 function in making proper cell fate decisions. USF1 stabilizes the p53 protein and promotes a transient cell cycle arrest, in the presence of DNA damage. Thus, cell proliferation is maintained inappropriately in Usf1 KO mice and in USF1-deficient melanoma cells challenged by genotoxic stress. We further demonstrate that the loss of USF1 compromises p53 stability by enhancing p53-MDM2 complex formation and MDM2-mediated degradation of p53. In USF1-deficient cells, the level of p53 can be restored by the re-expression of full-length USF1 protein similarly to what is observed using Nutlin-3, a specific inhibitor that prevents p53-MDM2 interaction. Consistent with a new function for USF1, a USF1 truncated protein lacking its DNA-binding and transactivation domains can also restore the induction and activity of p53. These findings establish that p53 function requires the ubiquitous stress sensor USF1 for appropriate cell fate decisions in response to DNA-damage. They underscore the new role of USF1 and give new clues of how p53 loss of function can occur in any cell type. Finally, these findings are of clinical relevance because they provide new therapeutic prospects in stabilizing and reactivating the p53 pathway. Cancer is a complex disease that is characterized by the sequential accumulation of genetic mutations. Exposure to environmental agents, such as solar ultraviolet, induces such alterations and thus contributes to the development of genomic instability. The tumor suppressor p53 has a central role in orchestrating cellular responses to genotoxic stress. In response to DNA-damage, p53 is stabilized and activated to direct cell fate decisions. Cells in which p53 stabilization is compromised become more vulnerable to mutagenic agents and hence the mutation rate increases, which promotes tumor development. Stabilization of p53 is thus a critical step towards cancer prevention. Using a genetic approach, we demonstrate that the ubiquitous transcription factor Upstream Stimulatory factor 1 (USF1) is required for immediate p53 stabilization and appropriate cell fate decisions following genotoxic stress. Furthermore, we show that this involves a novel function of USF1 that underscores its critical role as a stress sensor. The loss of USF1 expression should thus be considered as a potential initiator of tumorigenesis in the context of environmental insults.
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Rath A, Hromas R, De Benedetti A. Fidelity of end joining in mammalian episomes and the impact of Metnase on joint processing. BMC Mol Biol 2014; 15:6. [PMID: 24655462 PMCID: PMC3998112 DOI: 10.1186/1471-2199-15-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Accepted: 03/12/2014] [Indexed: 12/13/2022] Open
Abstract
Background Double Stranded Breaks (DSBs) are the most serious form of DNA damage and are repaired via homologous recombination repair (HRR) or non-homologous end joining (NHEJ). NHEJ predominates in mammalian cells at most stages of the cell cycle, and it is viewed as ‘error-prone’, although this notion has not been sufficiently challenged due to shortcomings of many current systems. Multi-copy episomes provide a large pool of genetic material where repair can be studied, as repaired plasmids can be back-cloned into bacteria and characterized for sequence alterations. Here, we used EBV-based episomes carrying 3 resistance marker genes in repair studies where a single DSB is generated with virally-encoded HO endonuclease cleaving rapidly at high efficiency for a brief time post-infection. We employed PCR and Southern blot to follow the kinetics of repair and formation of processing intermediates, and replica plating to screen for plasmids with altered joints resulting in loss of chloramphenicol resistance. Further, we employed this system to study the role of Metnase. Metnase is only found in humans and primates and is a key component of the NHEJ pathway, but its function is not fully characterized in intact cells. Results We found that repair of episomes by end-joining was highly accurate in 293 T cells that lack Metnase. Less than 10% of the rescued plasmids showed deletions. Instead, HEK293 cells (that do express Metnase) or 293 T transfected with Metnase revealed a large number of rescued plasmids with altered repaired joint, typically in the form of large deletions. Moreover, quantitative PCR and Southern blotting revealed less accurately repaired plasmids in Metnase expressing cells. Conclusions Our careful re-examination of fidelity of NHEJ repair in mammalian cells carrying a 3′ cohesive overhang at the ends revealed that the repair is efficient and highly accurate, and predominant over HRR. However, the background of the cells is important in establishing accuracy; with human cells perhaps surprisingly much more prone to generate deletions at the repaired junctions, if/when Metnase is abundantly expressed.
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Affiliation(s)
| | | | - Arrigo De Benedetti
- Department of Biochemistry and Molecular Biology, Louisiana State University Health Sciences Center, 1501 Kings Highway, Shreveport, LA 71130, USA.
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Genotoxic anti-cancer agents and their relationship to DNA damage, mitosis, and checkpoint adaptation in proliferating cancer cells. Int J Mol Sci 2014; 15:3403-31. [PMID: 24573252 PMCID: PMC3975345 DOI: 10.3390/ijms15033403] [Citation(s) in RCA: 114] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Revised: 01/22/2014] [Accepted: 02/14/2014] [Indexed: 12/19/2022] Open
Abstract
When a human cell detects damaged DNA, it initiates the DNA damage response (DDR) that permits it to repair the damage and avoid transmitting it to daughter cells. Despite this response, changes to the genome occur and some cells, such as proliferating cancer cells, are prone to genome instability. The cellular processes that lead to genomic changes after a genotoxic event are not well understood. Our research focuses on the relationship between genotoxic cancer drugs and checkpoint adaptation, which is the process of mitosis with damaged DNA. We examine the types of DNA damage induced by widely used cancer drugs and describe their effects upon proliferating cancer cells. There is evidence that cell death caused by genotoxic cancer drugs in some cases includes exiting a DNA damage cell cycle arrest and entry into mitosis. Furthermore, some cells are able to survive this process at a time when the genome is most susceptible to change or rearrangement. Checkpoint adaptation is poorly characterised in human cells; we predict that increasing our understanding of this pathway may help to understand genomic instability in cancer cells and provide insight into methods to improve the efficacy of current cancer therapies.
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Mandal S, Chatterjee N, Das S, Saha KD, Chaudhuri K. Magnetic core–shell nanoprobe for sensitive killing of cancer cells via induction with a strong external magnetic field. RSC Adv 2014. [DOI: 10.1039/c4ra01407c] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The title system, composed of a highly magnetic core surrounded by a thin arsenite shell, has been synthesized and applied to the magnetically facilitated targeting of anticancer agent (sodium arsenite) at lower dose with minimal side effects and higher efficacy in a biocompatible manner.
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Affiliation(s)
- Samir Mandal
- Molecular and Human Genetics Division
- CSIR-Indian Institute of Chemical Biology
- Kolkata-700 032, India
| | - Nabanita Chatterjee
- Cancer Biology and Inflammatory Disorder Division
- CSIR-Indian Institute of Chemical Biology
- Kolkata 700032, India
| | - Subhadip Das
- Cancer Biology and Inflammatory Disorder Division
- CSIR-Indian Institute of Chemical Biology
- Kolkata 700032, India
| | - Krishna Das Saha
- Cancer Biology and Inflammatory Disorder Division
- CSIR-Indian Institute of Chemical Biology
- Kolkata 700032, India
| | - Keya Chaudhuri
- Molecular and Human Genetics Division
- CSIR-Indian Institute of Chemical Biology
- Kolkata-700 032, India
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Loewer A, Karanam K, Mock C, Lahav G. The p53 response in single cells is linearly correlated to the number of DNA breaks without a distinct threshold. BMC Biol 2013; 11:114. [PMID: 24252182 PMCID: PMC3906995 DOI: 10.1186/1741-7007-11-114] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Accepted: 11/13/2013] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND The tumor suppressor protein p53 is activated by cellular stress. DNA double strand breaks (DSBs) induce the activation of the kinase ATM, which stabilizes p53 and activates its transcriptional activity. Single cell analysis revealed that DSBs induced by gamma irradiation trigger p53 accumulation in a series of pulses that vary in number from cell to cell. Higher levels of irradiation increase the number of p53 pulses suggesting that they arise from periodic examination of the damage by ATM. If damage persists, additional pulses of p53 are triggered. The threshold of damage required for activating a p53 pulse is unclear. Previous studies that averaged the response across cell populations suggested that one or two DNA breaks are sufficient for activating ATM and p53. However, it is possible that by averaging over a population of cells important features of the dependency between DNA breaks and p53 dynamics are missed. RESULTS Using fluorescent reporters we developed a system for following in individual cells the number of DSBs, the kinetics of repair and the p53 response. We found a large variation in the initial number of DSBs and the rate of repair between individual cells. Cells with higher number of DSBs had higher probability of showing a p53 pulse. However, there was no distinct threshold number of breaks for inducing a p53 pulse. We present evidence that the decision to activate p53 given a specific number of breaks is not entirely stochastic, but instead is influenced by both cell-intrinsic factors and previous exposure to DNA damage. We also show that the natural variations in the initial amount of p53, rate of DSB repair and cell cycle phase do not affect the probability of activating p53 in response to DNA damage. CONCLUSIONS The use of fluorescent reporters to quantify DNA damage and p53 levels in live cells provided a quantitative analysis of the complex interrelationships between both processes. Our study shows that p53 activation differs even between cells that have a similar number of DNA breaks. Understanding the origin and consequences of such variability in normal and cancerous cells is crucial for developing efficient and selective therapeutic interventions.
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Affiliation(s)
- Alexander Loewer
- Department of Systems Biology, Harvard Medical School, Boston, MA 02115, USA
- Berlin Institute for Medical Systems Biology, Max Delbrueck Center for Molecular Medicine, 13125 Berlin-Buch, Germany
| | - Ketki Karanam
- Department of Systems Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Caroline Mock
- Department of Systems Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Galit Lahav
- Department of Systems Biology, Harvard Medical School, Boston, MA 02115, USA
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