1
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Elfman J, Goins L, Heller T, Singh S, Wang YH, Li H. Discovery of a polymorphic gene fusion via bottom-up chimeric RNA prediction. Nucleic Acids Res 2024; 52:4409-4421. [PMID: 38587197 PMCID: PMC11077074 DOI: 10.1093/nar/gkae258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2022] [Accepted: 03/27/2024] [Indexed: 04/09/2024] Open
Abstract
Gene fusions and their chimeric products are commonly linked with cancer. However, recent studies have found chimeric transcripts in non-cancer tissues and cell lines. Large-scale efforts to annotate structural variations have identified gene fusions capable of generating chimeric transcripts even in normal tissues. In this study, we present a bottom-up approach targeting population-specific chimeric RNAs, identifying 58 such instances in the GTEx cohort, including notable cases such as SUZ12P1-CRLF3, TFG-ADGRG7 and TRPM4-PPFIA3, which possess distinct patterns across different ancestry groups. We provide direct evidence for an additional 29 polymorphic chimeric RNAs with associated structural variants, revealing 13 novel rare structural variants. Additionally, we utilize the All of Us dataset and a large cohort of clinical samples to characterize the association of the SUZ12P1-CRLF3-causing variant with patient phenotypes. Our study showcases SUZ12P1-CRLF3 as a representative example, illustrating the identification of elusive structural variants by focusing on those producing population-specific fusion transcripts.
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Affiliation(s)
- Justin Elfman
- Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA 22903, USA
| | - Lynette Goins
- Department of Biological Sciences, Clemson University, Clemson, SC 29631, USA
| | - Tessa Heller
- Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA 22903, USA
| | - Sandeep Singh
- Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA 22903, USA
- Computational Toxicology Facility, CSIR-Indian Institute of Toxicology Research, Lucknow, 226001, Uttar Pradesh, India
| | - Yuh-Hwa Wang
- Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA 22903, USA
| | - Hui Li
- Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA 22903, USA
- Department of Pathology, University of Virginia, Charlottesville, VA 22903, USA
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2
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Raimer Young HM, Hou PC, Bartosik AR, Atkin ND, Wang L, Wang Z, Ratan A, Zang C, Wang YH. DNA fragility at topologically associated domain boundaries is promoted by alternative DNA secondary structure and topoisomerase II activity. Nucleic Acids Res 2024; 52:3837-3855. [PMID: 38452213 DOI: 10.1093/nar/gkae164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Revised: 02/03/2024] [Accepted: 02/23/2024] [Indexed: 03/09/2024] Open
Abstract
CCCTC-binding factor (CTCF) binding sites are hotspots of genome instability. Although many factors have been associated with CTCF binding site fragility, no study has integrated all fragility-related factors to understand the mechanism(s) of how they work together. Using an unbiased, genome-wide approach, we found that DNA double-strand breaks (DSBs) are enriched at strong, but not weak, CTCF binding sites in five human cell types. Energetically favorable alternative DNA secondary structures underlie strong CTCF binding sites. These structures coincided with the location of topoisomerase II (TOP2) cleavage complex, suggesting that DNA secondary structure acts as a recognition sequence for TOP2 binding and cleavage at CTCF binding sites. Furthermore, CTCF knockdown significantly increased DSBs at strong CTCF binding sites and at CTCF sites that are located at topologically associated domain (TAD) boundaries. TAD boundary-associated CTCF sites that lost CTCF upon knockdown displayed increased DSBs when compared to the gained sites, and those lost sites are overrepresented with G-quadruplexes, suggesting that the structures act as boundary insulators in the absence of CTCF, and contribute to increased DSBs. These results model how alternative DNA secondary structures facilitate recruitment of TOP2 to CTCF binding sites, providing mechanistic insight into DNA fragility at CTCF binding sites.
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Affiliation(s)
- Heather M Raimer Young
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA 22908-0733, USA
| | - Pei-Chi Hou
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA 22908-0733, USA
| | - Anna R Bartosik
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA 22908-0733, USA
| | - Naomi D Atkin
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA 22908-0733, USA
| | - Lixin Wang
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA 22908, USA
| | - Zhenjia Wang
- Center for Public Health Genomics, University of Virginia School of Medicine, Charlottesville, VA 22908-0717, USA
| | - Aakrosh Ratan
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA 22908-0733, USA
- Center for Public Health Genomics, University of Virginia School of Medicine, Charlottesville, VA 22908-0717, USA
- Department of Public Health Sciences, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
- University of Virginia Comprehensive Cancer Center, Charlottesville, VA 22908, USA
| | - Chongzhi Zang
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA 22908-0733, USA
- Center for Public Health Genomics, University of Virginia School of Medicine, Charlottesville, VA 22908-0717, USA
- Department of Public Health Sciences, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
- University of Virginia Comprehensive Cancer Center, Charlottesville, VA 22908, USA
| | - Yuh-Hwa Wang
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA 22908-0733, USA
- University of Virginia Comprehensive Cancer Center, Charlottesville, VA 22908, USA
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3
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Pinto LM, Pailas A, Bondarchenko M, Sharma AB, Neumann K, Rizzo AJ, Jeanty C, Nicot N, Racca C, Graham MK, Naughton C, Liu Y, Chen CL, Meakin PJ, Gilbert N, Britton S, Meeker AK, Heaphy CM, Larminat F, Van Dyck E. DAXX promotes centromeric stability independently of ATRX by preventing the accumulation of R-loop-induced DNA double-stranded breaks. Nucleic Acids Res 2024; 52:1136-1155. [PMID: 38038252 PMCID: PMC10853780 DOI: 10.1093/nar/gkad1141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 11/08/2023] [Accepted: 11/13/2023] [Indexed: 12/02/2023] Open
Abstract
Maintaining chromatin integrity at the repetitive non-coding DNA sequences underlying centromeres is crucial to prevent replicative stress, DNA breaks and genomic instability. The concerted action of transcriptional repressors, chromatin remodelling complexes and epigenetic factors controls transcription and chromatin structure in these regions. The histone chaperone complex ATRX/DAXX is involved in the establishment and maintenance of centromeric chromatin through the deposition of the histone variant H3.3. ATRX and DAXX have also evolved mutually-independent functions in transcription and chromatin dynamics. Here, using paediatric glioma and pancreatic neuroendocrine tumor cell lines, we identify a novel ATRX-independent function for DAXX in promoting genome stability by preventing transcription-associated R-loop accumulation and DNA double-strand break formation at centromeres. This function of DAXX required its interaction with histone H3.3 but was independent of H3.3 deposition and did not reflect a role in the repression of centromeric transcription. DAXX depletion mobilized BRCA1 at centromeres, in line with BRCA1 role in counteracting centromeric R-loop accumulation. Our results provide novel insights into the mechanisms protecting the human genome from chromosomal instability, as well as potential perspectives in the treatment of cancers with DAXX alterations.
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Affiliation(s)
- Lia M Pinto
- DNA Repair and Chemoresistance Group, Department of Cancer Research, Luxembourg Institute of Health (LIH), L-1210 Luxembourg, Luxembourg
- Faculty of Science, Technology and Communication, University of Luxembourg, L-4365 Esch-sur-Alzette, Luxembourg
- Discovery & Translational Science Department, Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds LS2 9JT, UK
| | - Alexandros Pailas
- DNA Repair and Chemoresistance Group, Department of Cancer Research, Luxembourg Institute of Health (LIH), L-1210 Luxembourg, Luxembourg
- Faculty of Science, Technology and Communication, University of Luxembourg, L-4365 Esch-sur-Alzette, Luxembourg
| | - Max Bondarchenko
- DNA Repair and Chemoresistance Group, Department of Cancer Research, Luxembourg Institute of Health (LIH), L-1210 Luxembourg, Luxembourg
- Faculty of Science, Technology and Communication, University of Luxembourg, L-4365 Esch-sur-Alzette, Luxembourg
| | - Abhishek Bharadwaj Sharma
- DNA Repair and Chemoresistance Group, Department of Cancer Research, Luxembourg Institute of Health (LIH), L-1210 Luxembourg, Luxembourg
| | - Katrin Neumann
- DNA Repair and Chemoresistance Group, Department of Cancer Research, Luxembourg Institute of Health (LIH), L-1210 Luxembourg, Luxembourg
| | - Anthony J Rizzo
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD 21231, USA
| | - Céline Jeanty
- DNA Repair and Chemoresistance Group, Department of Cancer Research, Luxembourg Institute of Health (LIH), L-1210 Luxembourg, Luxembourg
| | - Nathalie Nicot
- Translational Medicine Operations Hub, Luxembourg Institute of Health (LIH), Luxembourg, Luxembourg
| | - Carine Racca
- Institut de Pharmacologie et Biologie Structurale (IPBS), Université de Toulouse, CNRS, Université Toulouse III - Paul Sabatier (UT3), 31077 Toulouse Cedex 4, France
| | - Mindy K Graham
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD 21231, USA
| | - Catherine Naughton
- Medical Research Council Human Genetics Unit, Institute of Genetics and Molecular Medicine, The University of Edinburgh, Edinburgh EH4 1QY, UK
| | - Yaqun Liu
- Institut Curie, PSL Research University, CNRS UMR3244, Dynamics of Genetic Information, Sorbonne Université, 75248 Paris Cedex 05, France
| | - Chun-Long Chen
- Institut Curie, PSL Research University, CNRS UMR3244, Dynamics of Genetic Information, Sorbonne Université, 75248 Paris Cedex 05, France
| | - Paul J Meakin
- Discovery & Translational Science Department, Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds LS2 9JT, UK
| | - Nick Gilbert
- Medical Research Council Human Genetics Unit, Institute of Genetics and Molecular Medicine, The University of Edinburgh, Edinburgh EH4 1QY, UK
| | - Sébastien Britton
- Institut de Pharmacologie et Biologie Structurale (IPBS), Université de Toulouse, CNRS, Université Toulouse III - Paul Sabatier (UT3), 31077 Toulouse Cedex 4, France
| | - Alan K Meeker
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD 21231, USA
| | - Christopher M Heaphy
- Department of Medicine, Boston University School of Medicine, Boston, MA 02118, USA
| | - Florence Larminat
- Institut de Pharmacologie et Biologie Structurale (IPBS), Université de Toulouse, CNRS, Université Toulouse III - Paul Sabatier (UT3), 31077 Toulouse Cedex 4, France
| | - Eric Van Dyck
- DNA Repair and Chemoresistance Group, Department of Cancer Research, Luxembourg Institute of Health (LIH), L-1210 Luxembourg, Luxembourg
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4
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Wang XQ, Li LL, Lou P, Zhang Q, Wang Y. Noval ceRNA axis-mediated high expression of TOP2A correlates with poor prognosis and tumor immune infiltration of hepatocellular carcinoma. Transl Cancer Res 2023; 12:3486-3502. [PMID: 38193002 PMCID: PMC10774052 DOI: 10.21037/tcr-23-755] [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: 05/03/2023] [Accepted: 10/20/2023] [Indexed: 01/10/2024]
Abstract
Background Hepatocellular carcinoma (HCC) is a highly malignant tumor with limited treatment options, suboptimal efficacy, and poor prognosis, resulting in an economic burden to countries worldwide. TOP2A is a mammalian protein that plays a vital role in DNA replication. Previous studies have shown that upregulation of TOP2A expression is associated with tumorigenesis and progression in various cancers, but the exact mechanism of upregulation remains unclear. Methods We first conducted a pan-cancer analysis using The Cancer Genome Atlas (TCGA) and Genotype-Tissue Expression (GTEx) databases to study the oncogenicity of TOP2A through the cBioPortal database. Next, using The Encyclopedia of RNA Interactomes (ENCORI) database, we identified microRNAs (miRNAs) that are associated with the downregulation of TOP2A and investigated potential long non-coding RNAs (lncRNAs) that may act as competing endogenous RNAs (ceRNAs) by binding to candidate miRNAs. We then analyzed immune cell infiltration and immune checkpoints using the TIMER database. Finally, we performed a multivariate regression analysis using lncRNAs and clinical pathological characteristics, constructed a nomogram to predict the prognosis of HCC based on the analysis results, and evaluated its diagnostic efficiency. Results TOP2A was highly expressed in HCC and was associated with poor patient prognosis. TOP2A was subject to post-transcriptional regulation in HCC, with the ceRNA mechanism being a significant pathway. miR-139-5p was an important miRNA that suppressed the upregulation of TOP2A in HCC, and patients with low expression of miR-139-5p had worse overall survival (OS). After screening and analysis, three lncRNAs, AC078846.1, AC124798.1 and SNHG3, were found to inhibit the activity of miR-139-5p through the ceRNA mechanism, and patients with high expression of these three lncRNAs had worse prognosis. In addition, TOP2A was found to be closely related to tumor-infiltrating immune cells (TIICs) and immune checkpoints. A nomogram constructed using the three lncRNAs and selected clinicopathological features showed good predictive value for the prognosis of liver cancer. Conclusions The TOP2A-miR-139-5p-AC078846.1/AC124798.1/SNHG3 axis plays a significant role in the progression of HCC and leads to poor patient outcomes. Additionally, TOP2A influences the development of HCC by affecting TIICs and immune checkpoints. A nomogram constructed using the three lncRNAs and clinicopathological features has good clinical utility.
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Affiliation(s)
- Xiao-Qing Wang
- Interventional Department, Shandong Public Health Clinical Center, Shandong University, Jinan, China
| | - Li-Li Li
- Interventional Department, Shandong Public Health Clinical Center, Shandong University, Jinan, China
| | - Peng Lou
- Vascular Surgery, Shandong Public Health Clinical Center, Shandong University, Jinan, China
| | - Qian Zhang
- Interventional Department, Shandong Public Health Clinical Center, Shandong University, Jinan, China
| | - Yang Wang
- Vascular Surgery, Shandong Public Health Clinical Center, Shandong University, Jinan, China
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5
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Chatzinikolaou G, Stratigi K, Siametis A, Goulielmaki E, Akalestou-Clocher A, Tsamardinos I, Topalis P, Austin C, Bouwman BA, Crosetto N, Altmüller J, Garinis GA. XPF interacts with TOP2B for R-loop processing and DNA looping on actively transcribed genes. SCIENCE ADVANCES 2023; 9:eadi2095. [PMID: 37939182 PMCID: PMC10631727 DOI: 10.1126/sciadv.adi2095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Accepted: 10/05/2023] [Indexed: 11/10/2023]
Abstract
Co-transcriptional RNA-DNA hybrids can not only cause DNA damage threatening genome integrity but also regulate gene activity in a mechanism that remains unclear. Here, we show that the nucleotide excision repair factor XPF interacts with the insulator binding protein CTCF and the cohesin subunits SMC1A and SMC3, leading to R-loop-dependent DNA looping upon transcription activation. To facilitate R-loop processing, XPF interacts and recruits with TOP2B on active gene promoters, leading to double-strand break accumulation and the activation of a DNA damage response. Abrogation of TOP2B leads to the diminished recruitment of XPF, CTCF, and the cohesin subunits to promoters of actively transcribed genes and R-loops and the concurrent impairment of CTCF-mediated DNA looping. Together, our findings disclose an essential role for XPF with TOP2B and the CTCF/cohesin complex in R-loop processing for transcription activation with important ramifications for DNA repair-deficient syndromes associated with transcription-associated DNA damage.
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Affiliation(s)
- Georgia Chatzinikolaou
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology–Hellas, GR70013, Heraklion, Crete, Greece
| | - Kalliopi Stratigi
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology–Hellas, GR70013, Heraklion, Crete, Greece
| | - Athanasios Siametis
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology–Hellas, GR70013, Heraklion, Crete, Greece
- Department of Biology, University of Crete, Heraklion, Crete, Greece
| | - Evi Goulielmaki
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology–Hellas, GR70013, Heraklion, Crete, Greece
| | - Alexia Akalestou-Clocher
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology–Hellas, GR70013, Heraklion, Crete, Greece
- Department of Biology, University of Crete, Heraklion, Crete, Greece
| | - Ioannis Tsamardinos
- Computer Science Department of University of Crete, Heraklion, Crete, Greece
| | - Pantelis Topalis
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology–Hellas, GR70013, Heraklion, Crete, Greece
| | - Caroline Austin
- Biosciences Institute, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Britta A. M. Bouwman
- Division of Microbiology, Tumor and Cell Biology, Karolinska Institutet and Science for Life Laboratory, Stockholm 17177, Sweden
| | - Nicola Crosetto
- Division of Microbiology, Tumor and Cell Biology, Karolinska Institutet and Science for Life Laboratory, Stockholm 17177, Sweden
- Human Technopole, Viale Rita Levi-Montalcini 1, 22157 Milan, Italy
| | - Janine Altmüller
- Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin Institute of Health at Charité–Universitätsmedizin Berlin, Core Facility Genomics, Charitéplatz 1, 10117 Berlin, Germany
| | - George A. Garinis
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology–Hellas, GR70013, Heraklion, Crete, Greece
- Department of Biology, University of Crete, Heraklion, Crete, Greece
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6
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Rose AM, Goncalves T, Cunniffe S, Geiller HEB, Kent T, Shepherd S, Ratnaweera M, O’Sullivan R, Gibbons R, Clynes D. Induction of the alternative lengthening of telomeres pathway by trapping of proteins on DNA. Nucleic Acids Res 2023; 51:6509-6527. [PMID: 36940725 PMCID: PMC10359465 DOI: 10.1093/nar/gkad150] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Revised: 02/06/2023] [Accepted: 02/21/2023] [Indexed: 03/23/2023] Open
Abstract
Telomere maintenance is a hallmark of malignant cells and allows cancers to divide indefinitely. In some cancers, this is achieved through the alternative lengthening of telomeres (ALT) pathway. Whilst loss of ATRX is a near universal feature of ALT-cancers, it is insufficient in isolation. As such, other cellular events must be necessary - but the exact nature of the secondary events has remained elusive. Here, we report that trapping of proteins (such as TOP1, TOP2A and PARP1) on DNA leads to ALT induction in cells lacking ATRX. We demonstrate that protein-trapping chemotherapeutic agents, such as etoposide, camptothecin and talazoparib, induce ALT markers specifically in ATRX-null cells. Further, we show that treatment with G4-stabilising drugs cause an increase in trapped TOP2A levels which leads to ALT induction in ATRX-null cells. This process is MUS81-endonuclease and break-induced replication dependent, suggesting that protein trapping leads to replication fork stalling, with these forks being aberrantly processed in the absence of ATRX. Finally, we show ALT-positive cells harbour a higher load of genome-wide trapped proteins, such as TOP1, and knockdown of TOP1 reduced ALT activity. Taken together, these findings suggest that protein trapping is a fundamental driving force behind ALT-biology in ATRX-deficient malignancies.
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Affiliation(s)
- Anna M Rose
- MRC Molecular Haematology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DS, UK
- Department of Paediatrics, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DS, UK
| | - Tomas Goncalves
- MRC Molecular Haematology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DS, UK
| | - Siobhan Cunniffe
- Department of Oncology, University of Oxford, Oxford OX3 7DQ, UK
| | | | - Thomas Kent
- MRC Molecular Haematology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DS, UK
| | - Sam Shepherd
- Department of Oncology, University of Oxford, Oxford OX3 7DQ, UK
| | | | - Roderick J O’Sullivan
- Department of Pharmacology and Chemical Biology, UPMC Hillman Cancer Center, University of Pittsburgh, Pittsburgh, PA, USA
| | - Richard J Gibbons
- MRC Molecular Haematology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DS, UK
| | - David Clynes
- Department of Oncology, University of Oxford, Oxford OX3 7DQ, UK
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7
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Burden F, Ellis PI, Farré M. A shared 'vulnerability code' underpins varying sources of DNA damage throughout paternal germline transmission in mouse. Nucleic Acids Res 2023; 51:2319-2332. [PMID: 36806949 PMCID: PMC10018361 DOI: 10.1093/nar/gkad089] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Revised: 01/23/2023] [Accepted: 02/02/2023] [Indexed: 02/22/2023] Open
Abstract
During mammalian spermatogenesis, the paternal genome is extensively remodelled via replacement of histones with protamines forming the highly compact mature sperm nucleus. Compaction occurs in post-meiotic spermatids and is accompanied by extensive double strand break (DSB) formation. We investigate the epigenomic and genomic context of mouse spermatid DSBs, identifying primary sequence motifs, secondary DNA structures and chromatin contexts associated with this damage. Consistent with previously published results we find spermatid DSBs positively associated with short tandem repeats and LINE elements. We further show spermatid DSBs preferentially occur in association with (CA)n, (NA)n and (RY)n repeats, in predicted Z-DNA, are not associated with G-quadruplexes, are preferentially found in regions of low histone mark coverage and engage the remodelling/NHEJ factor BRD4. Locations incurring DSBs in spermatids also show distinct epigenetic profiles throughout later developmental stages: regions retaining histones in mature sperm, regions susceptible to oxidative damage in mature sperm, and fragile two-cell like embryonic stem cell regions bound by ZSCAN4 all co-localise with spermatid DSBs and with each other. Our results point to a common 'vulnerability code' unifying several types of DNA damage occurring on the paternal genome during reproduction, potentially underpinned by torsional changes during sperm chromatin remodelling.
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Affiliation(s)
| | - Peter J I Ellis
- To whom correspondence should be addressed. Tel: +44 1227 823526;
| | - Marta Farré
- Correspondence may also be addressed to Marta Farré. Tel: +44 1227 823697;
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8
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Xiao H, Wang S, Tang Y, Li S, Jiang Y, Yang Y, Zhang Y, Han Y, Wu X, Zheng L, Li Y, Gao Y. Absence of terminal deoxynucleotidyl transferase expression in T-ALL/LBL accumulates chromosomal abnormalities to induce drug resistance. Int J Cancer 2023; 152:2383-2395. [PMID: 36757202 DOI: 10.1002/ijc.34465] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2022] [Revised: 01/21/2023] [Accepted: 01/30/2023] [Indexed: 02/10/2023]
Abstract
T-acute lymphoblastic leukemia/lymphoma (T-ALL/LBL) is a malignant neoplasm of immature lymphoblasts. Terminal deoxynucleotidyl transferase (TDT) is a template-independent DNA polymerase that plays an essential role in generating diversity for immunoglobulin genes. T-ALL/LBL patients with TDT- have a worse prognosis. However, how TDT- promotes the disease progression of T-ALL/LBL remains unknown. Here we analyzed the prognosis of T-ALL/LBL patients in Shanghai Children's Medical Center (SCMC) and confirmed that TDT- patients had a higher rate of recurrence and remission failure and worse outcomes. Cellular experiments demonstrated that TDT was involved in DNA damage repair. TDT knockout delayed DNA repair, arrested the cell cycle and decreased apoptosis to induce the accumulation of chromosomal abnormalities and tolerance to abnormal karyotypes. Our study demonstrated that the poor outcomes in TDT- T-ALL/LBL might be due to the drug resistance (VP16 and MTX) induced by chromosomal abnormalities. Our findings revealed novel functions and mechanisms of TDT in T-ALL/LBL and supported that hematopoietic stem cell transplantation (HSCT) might be a better choice for these patients.
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Affiliation(s)
- Hui Xiao
- Department of Hematology & Oncology, Pediatric Translational Medicine Institute, Shanghai Children's Medical Center, School of Medicine, Shanghai Jiao Tong University, National Health Committee Key Laboratory of Pediatric Hematology & Oncology, Shanghai, China
| | - Siqi Wang
- Department of Hematology & Oncology, Pediatric Translational Medicine Institute, Shanghai Children's Medical Center, School of Medicine, Shanghai Jiao Tong University, National Health Committee Key Laboratory of Pediatric Hematology & Oncology, Shanghai, China
| | - Yuejia Tang
- Department of Hematology & Oncology, Pediatric Translational Medicine Institute, Shanghai Children's Medical Center, School of Medicine, Shanghai Jiao Tong University, National Health Committee Key Laboratory of Pediatric Hematology & Oncology, Shanghai, China
| | - Shanshan Li
- Department of Hematology & Oncology, Pediatric Translational Medicine Institute, Shanghai Children's Medical Center, School of Medicine, Shanghai Jiao Tong University, National Health Committee Key Laboratory of Pediatric Hematology & Oncology, Shanghai, China
| | - Yufeng Jiang
- Department of Hematology & Oncology, Pediatric Translational Medicine Institute, Shanghai Children's Medical Center, School of Medicine, Shanghai Jiao Tong University, National Health Committee Key Laboratory of Pediatric Hematology & Oncology, Shanghai, China
| | - Yi Yang
- Department of Hematology & Oncology, Pediatric Translational Medicine Institute, Shanghai Children's Medical Center, School of Medicine, Shanghai Jiao Tong University, National Health Committee Key Laboratory of Pediatric Hematology & Oncology, Shanghai, China
| | - Yinwen Zhang
- Department of Hematology & Oncology, Pediatric Translational Medicine Institute, Shanghai Children's Medical Center, School of Medicine, Shanghai Jiao Tong University, National Health Committee Key Laboratory of Pediatric Hematology & Oncology, Shanghai, China
| | - Yali Han
- Department of Hematology & Oncology, Pediatric Translational Medicine Institute, Shanghai Children's Medical Center, School of Medicine, Shanghai Jiao Tong University, National Health Committee Key Laboratory of Pediatric Hematology & Oncology, Shanghai, China
| | - Xiaoyu Wu
- Department of Hematology & Oncology, Pediatric Translational Medicine Institute, Shanghai Children's Medical Center, School of Medicine, Shanghai Jiao Tong University, National Health Committee Key Laboratory of Pediatric Hematology & Oncology, Shanghai, China
| | - Liang Zheng
- Department of Hematology & Oncology, Pediatric Translational Medicine Institute, Shanghai Children's Medical Center, School of Medicine, Shanghai Jiao Tong University, National Health Committee Key Laboratory of Pediatric Hematology & Oncology, Shanghai, China
| | - Yanxin Li
- Department of Hematology & Oncology, Pediatric Translational Medicine Institute, Shanghai Children's Medical Center, School of Medicine, Shanghai Jiao Tong University, National Health Committee Key Laboratory of Pediatric Hematology & Oncology, Shanghai, China
| | - Yijin Gao
- Department of Hematology & Oncology, Pediatric Translational Medicine Institute, Shanghai Children's Medical Center, School of Medicine, Shanghai Jiao Tong University, National Health Committee Key Laboratory of Pediatric Hematology & Oncology, Shanghai, China
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9
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Elfman J, Goins L, Heller T, Singh S, Wang YH, Li H. Discovery of A Polymorphic Gene Fusion via Bottom-Up Chimeric RNA Prediction. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.02.526864. [PMID: 36778239 PMCID: PMC9915695 DOI: 10.1101/2023.02.02.526864] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Gene fusions and their chimeric products are typically considered hallmarks of cancer. However, recent studies have found chimeric transcripts in non-cancer tissues and cell lines. In addition, efforts to annotate structural variation at large scale have found examples of gene fusions with potential to produce chimeric transcripts in normal tissues. In this report, we provide a means for targeting population-specific chimeric RNAs to enrich for those generated by gene fusion events. We identify 57 such chimeric RNAs from the GTEx cohort, including SUZ12P1-CRLF3 and TFG-ADGRG7 , whose distribution we assessed across the populations of the 1000 Genomes Project. We reveal that SUZ12P1-CRLF3 results from a common complex structural variant in populations with African heritage, and identify its likely mechanism for formation. Additionally, we utilize a large cohort of clinical samples to characterize the SUZ12P1-CRLF3 chimeric RNA, and find an association between the variant and indications of Neurofibramatosis Type I. We present this gene fusion as a case study for identifying hard-to-find and potentially functional structural variants by selecting for those which produce population-specific fusion transcripts. KEY POINTS - Discovery of 57 polymorphic chimeric RNAs- Characterization of SUZ12P1-CRLF3 polymorphic chimeric RNA and corresponding rearrangement- Novel bottom-up approach to identify structural variants which produce transcribed gene fusions.
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Zhang J, Liu P, Chen J, Yao D, Liu Q, Zhang J, Zhang HW, Leung ELH, Yao XJ, Liu L. Upgrade of chrysomycin A as a novel topoisomerase II inhibitor to curb KRAS-mutant lung adenocarcinoma progression. Pharmacol Res 2023; 187:106565. [PMID: 36414124 DOI: 10.1016/j.phrs.2022.106565] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Revised: 11/13/2022] [Accepted: 11/18/2022] [Indexed: 11/20/2022]
Abstract
A primary strategy employed in cancer therapy is the inhibition of topoisomerase II (Topo II), implicated in cell survival. However, side effects and adverse reactions restrict the utilization of Topo II inhibitors. Thus, investigations focus on the discovery of novel compounds that are capable of inhibiting the Topo II enzyme and feature safer toxicological profiles. Herein, we upgrade an old antibiotic chrysomycin A from Streptomyces sp. 891 as a compelling Topo II enzyme inhibitor. Our results show that chrysomycin A is a new chemical entity. Notably, chrysomycin A targets the DNA-unwinding enzyme Topo II with an efficient binding potency and a significant inhibition of intracellular enzyme levels. Intriguingly, chrysomycin A kills KRAS-mutant lung adenocarcinoma cells and is negligible cytotoxic to normal cells at the cellular level, thus indicating a capability of potential treatment. Furthermore, mechanism studies demonstrate that chrysomycin A inhibits the Topo II enzyme and stimulates the accumulation of reactive oxygen species, thereby inducing DNA damage-mediated cancer cell apoptosis. Importantly, chrysomycin A exhibits excellent control of cancer progression and excellent safety in tumor-bearing models. Our results provide a chemical scaffold for the synthesis of new types of Topo II inhibitors and reveal a novel target for chrysomycin A to meet its further application.
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Affiliation(s)
- Junmin Zhang
- State Key Laboratory of Quality Research in Chinese Medicine, Dr. Neher's Biophysics Laboratory for Innovative Drug Discovery, Macau University of Science and Technology, Macau; School of Pharmacy, State Key Laboratory of Applied Organic Chemistry, and College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, China
| | - Pei Liu
- State Key Laboratory of Quality Research in Chinese Medicine, Dr. Neher's Biophysics Laboratory for Innovative Drug Discovery, Macau University of Science and Technology, Macau
| | - Jianwei Chen
- State Key Laboratory of Quality Research in Chinese Medicine, Dr. Neher's Biophysics Laboratory for Innovative Drug Discovery, Macau University of Science and Technology, Macau; School of Pharmaceutical Sciences, Zhejiang University of Technology, Hangzhou 310000, China
| | - Dahong Yao
- State Key Laboratory of Quality Research in Chinese Medicine, Dr. Neher's Biophysics Laboratory for Innovative Drug Discovery, Macau University of Science and Technology, Macau
| | - Qing Liu
- State Key Laboratory of Quality Research in Chinese Medicine, Dr. Neher's Biophysics Laboratory for Innovative Drug Discovery, Macau University of Science and Technology, Macau
| | - Juanhong Zhang
- State Key Laboratory of Quality Research in Chinese Medicine, Dr. Neher's Biophysics Laboratory for Innovative Drug Discovery, Macau University of Science and Technology, Macau; School of Pharmacy, State Key Laboratory of Applied Organic Chemistry, and College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, China; College of Life Science, Northwest Normal University, Lanzhou 730070, China
| | - Hua-Wei Zhang
- School of Pharmaceutical Sciences, Zhejiang University of Technology, Hangzhou 310000, China
| | - Elaine Lai-Han Leung
- Cancer Center, Faculty of Health Science, and MOE Frontiers Science Center for Precision Oncology, University of Macau, Macau.
| | - Xiao-Jun Yao
- State Key Laboratory of Quality Research in Chinese Medicine, Dr. Neher's Biophysics Laboratory for Innovative Drug Discovery, Macau University of Science and Technology, Macau.
| | - Liang Liu
- State Key Laboratory of Quality Research in Chinese Medicine, Dr. Neher's Biophysics Laboratory for Innovative Drug Discovery, Macau University of Science and Technology, Macau.
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Cowell IG, Austin CA. DNA fragility at the KMT2A/ MLL locus: insights from old and new technologies. Open Biol 2023; 13:220232. [PMID: 36629017 PMCID: PMC9832561 DOI: 10.1098/rsob.220232] [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] [Indexed: 01/12/2023] Open
Abstract
The Mixed-Lineage Leukaemia (MLL/KMT2A) gene is frequently rearranged in childhood and adult acute leukaemia (AL) and in secondary leukaemias occurring after therapy with DNA topoisomerase targeting anti-cancer agents such as etoposide (t-AL). MLL/KMT2A chromosome translocation break sites in AL patients fall within an 8 kb breakpoint cluster region (BCR). Furthermore, MLL/KMT2A break sites in t-AL frequently occur in a much smaller region, or hotspot, towards the 3' end of the BCR, close to the intron 11/exon 12 boundary. These findings have prompted considerable effort to uncover mechanisms behind the apparent fragility of the BCR and particularly the t-AL hotspot. Recent genome-wide analyses have demonstrated etoposide-induced DNA cleavage within the BCR, and it is tempting to conclude that this cleavage explains the distribution of translocation break sites in t-AL. However, the t-AL hotspot and the centre of the observed preferential DNA cleavage are offset by over 250 nucleotides, suggesting additional factors contribute to the distribution of t-AL break sites. We review these recent genomic datasets along with older experimental results, analysis of TOP2 DNA cleavage site preferences and DNA secondary structure features that may lead to break site selection in t-AL MLL/KMT2A translocations.
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Affiliation(s)
- Ian G. Cowell
- Biosciences Institute, The Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Caroline A. Austin
- Biosciences Institute, The Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
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12
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Zhang X. EVI1 Disruption Post Neuroblastoma Treatment: A Case Analysis of Treatment-Associated Acute Myeloid Leukemia in a Pediatric Patient. Case Rep Oncol 2023; 16:893-899. [PMID: 37900834 PMCID: PMC10601784 DOI: 10.1159/000533571] [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: 06/30/2023] [Accepted: 08/08/2023] [Indexed: 10/31/2023] Open
Abstract
In recent years, there has been an increasing focus on understanding the long-term consequences of pediatric cancer treatments, particularly the emergence of secondary malignant neoplasms (SMNs). Here, we present a case study highlighting the aftermath of treatment, where a pediatric patient, initially treated for neuroblastoma, developed treatment-related acute myeloid leukemia (tAML) 6 years later. Our investigation emphasizes the crucial role of EVI1 disruption in accelerating the progression of secondary tumors. This case underscores the significant risk of SMNs following pediatric cancer therapy. By analyzing genetic anomalies, we identified variations in the PTPN11 and KMT2C genes, suggesting a complex interplay between genetic susceptibility and chemotherapy-induced mutagenesis in tAML development. Furthermore, our exploration of the involvement of topoisomerase II inhibitors in tAML provides insights into potential future therapeutic approaches. Reporting this case is vital for deepening our understanding of the mechanisms driving SMNs after pediatric cancer treatments. Through a comprehensive analysis of genetic anomalies and treatment variables, we can offer more precise clinical diagnoses and treatment strategies. This approach holds the potential to reduce the occurrence of secondary tumors and improve the long-term prognosis for pediatric patients.
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Affiliation(s)
- Xin Zhang
- Department of Pediatric Hematology and Oncology, Xinhua Hospital Affilliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
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13
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The remodeling of Z-DNA in the mammalian germ line. Biochem Soc Trans 2022; 50:1875-1884. [PMID: 36454621 PMCID: PMC9788570 DOI: 10.1042/bst20221015] [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: 10/17/2022] [Revised: 11/14/2022] [Accepted: 11/15/2022] [Indexed: 12/02/2022]
Abstract
We recently discovered a novel biological process, the scheduled remodeling of Z-DNA structures in the developing fetal mouse male germ cells [Nat. Cell Biol. 24, 1141-1153]. This process affects purine/pyrimidine dinucleotide repeat (PPR) rich sequences, which can form stable left-handed Z-DNA structures. The protein that carries out this function is identified as ZBTB43, member of a large family of ZBTB proteins. Z-DNA remodeling by ZBTB43 not only coincides with global remodeling of DNA methylation and chromatin events in the male germ line, but it also is a prerequisite for de novo DNA methylation. When ZBTB43 changes DNA structure from the left-handed zigzag shaped Z-DNA to the regular smooth right-handed B-DNA, it also generates a suitable substrate for the de novo DNA methyltransferase, DNMT3A. By instructing de novo DNA methylation at PPRs in prospermatogonia, ZBTB43 safeguards epigenomic integrity of the male gamete. PPRs are fragile sequences, sites of large deletions and rearrangements in mammalian cells, and this fragility is thought to be due to Z-DNA structure formation rather than the sequence itself. This idea is now supported by the in vivo finding that DNA double strand breaks accumulate in mutant prospermatogonia which lack ZBTB43-dependent Z-DNA remodeling. If unrepaired, double stranded DNA breaks can lead to germ line mutations. Therefore, by preventing such breaks ZBTB43 is critical for guarding genome stability between generations. Here, we discuss the significance and implications of these findings in more detail.
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14
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McQuaid K, Pipier A, Cardin C, Monchaud D. Interactions of small molecules with DNA junctions. Nucleic Acids Res 2022; 50:12636-12656. [PMID: 36382400 PMCID: PMC9825177 DOI: 10.1093/nar/gkac1043] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 10/13/2022] [Accepted: 10/23/2022] [Indexed: 11/17/2022] Open
Abstract
The four natural DNA bases (A, T, G and C) associate in base pairs (A=T and G≡C), allowing the attached DNA strands to assemble into the canonical double helix of DNA (or duplex-DNA, also known as B-DNA). The intrinsic supramolecular properties of nucleobases make other associations possible (such as base triplets or quartets), which thus translates into a diversity of DNA structures beyond B-DNA. To date, the alphabet of DNA structures is ripe with approximately 20 letters (from A- to Z-DNA); however, only a few of them are being considered as key players in cell biology and, by extension, valuable targets for chemical biology intervention. In the present review, we summarise what is known about alternative DNA structures (what are they? When, where and how do they fold?) and proceed to discuss further about those considered nowadays as valuable therapeutic targets. We discuss in more detail the molecular tools (ligands) that have been recently developed to target these structures, particularly the three- and four-way DNA junctions, in order to intervene in the biological processes where they are involved. This new and stimulating chemical biology playground allows for devising innovative strategies to fight against genetic diseases.
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Affiliation(s)
- Kane T McQuaid
- Department of Chemistry, University of Reading, Whiteknights, Reading RG6 6AD, UK
| | - Angélique Pipier
- Institut de Chimie Moléculaire de l’Université de Bourgogne (ICMUB), CNRS UMR 6302, UBFC Dijon, 21078 Dijon, France
| | - Christine J Cardin
- Correspondence may also be addressed to Christine J. Cardin. Tel: +44 118 378 8215;
| | - David Monchaud
- To whom correspondence should be addressed. Tel: +33 380 399 043;
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Qin S, Yuan Y, Huang X, Tan Z, Hu X, Liu H, Pu Y, Ding YQ, Su Z, He C. Topoisomerase IIA in adult NSCs regulates SVZ neurogenesis by transcriptional activation of Usp37. Nucleic Acids Res 2022; 50:9319-9338. [PMID: 36029179 PMCID: PMC9458435 DOI: 10.1093/nar/gkac731] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 07/31/2022] [Accepted: 08/14/2022] [Indexed: 01/27/2023] Open
Abstract
Topoisomerase IIA (TOP2a) has traditionally been known as an important nuclear enzyme that resolves entanglements and relieves torsional stress of DNA double strands. However, its function in genomic transcriptional regulation remains largely unknown, especially during adult neurogenesis. Here, we show that TOP2a is preferentially expressed in neurogenic niches in the brain of adult mice, such as the subventricular zone (SVZ). Conditional knockout of Top2a in adult neural stem cells (NSCs) of the SVZ significantly inhibits their self-renewal and proliferation, and ultimately reduces neurogenesis. To gain insight into the molecular mechanisms by which TOP2a regulates adult NSCs, we perform RNA-sequencing (RNA-Seq) plus chromatin immunoprecipitation sequencing (ChIP-Seq) and identify ubiquitin-specific protease 37 (Usp37) as a direct TOP2a target gene. Importantly, overexpression of Usp37 is sufficient to rescue the impaired self-renewal ability of adult NSCs caused by Top2a knockdown. Taken together, this proof-of-principle study illustrates a TOP2a/Usp37-mediated novel molecular mechanism in adult neurogenesis, which will significantly expand our understanding of the function of topoisomerase in the adult brain.
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Affiliation(s)
- Shangyao Qin
- Institute of Neuroscience, Key Laboratory of Molecular Neurobiology of Ministry of Education and the Collaborative Innovation Center for Brain Science, Naval Medical University, Shanghai 200433, China
| | - Yimin Yuan
- Institute of Neuroscience, Key Laboratory of Molecular Neurobiology of Ministry of Education and the Collaborative Innovation Center for Brain Science, Naval Medical University, Shanghai 200433, China
| | - Xiao Huang
- Institute of Neuroscience, Key Laboratory of Molecular Neurobiology of Ministry of Education and the Collaborative Innovation Center for Brain Science, Naval Medical University, Shanghai 200433, China
| | - Zijian Tan
- Institute of Neuroscience, Key Laboratory of Molecular Neurobiology of Ministry of Education and the Collaborative Innovation Center for Brain Science, Naval Medical University, Shanghai 200433, China
| | - Xin Hu
- Institute of Neuroscience, Key Laboratory of Molecular Neurobiology of Ministry of Education and the Collaborative Innovation Center for Brain Science, Naval Medical University, Shanghai 200433, China
| | - Hong Liu
- Institute of Neuroscience, Key Laboratory of Molecular Neurobiology of Ministry of Education and the Collaborative Innovation Center for Brain Science, Naval Medical University, Shanghai 200433, China
| | - Yingyan Pu
- Institute of Neuroscience, Key Laboratory of Molecular Neurobiology of Ministry of Education and the Collaborative Innovation Center for Brain Science, Naval Medical University, Shanghai 200433, China
| | - Yu-qiang Ding
- Department of Laboratory Animal Science, and State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai 200032, China
| | - Zhida Su
- Institute of Neuroscience, Key Laboratory of Molecular Neurobiology of Ministry of Education and the Collaborative Innovation Center for Brain Science, Naval Medical University, Shanghai 200433, China
| | - Cheng He
- Institute of Neuroscience, Key Laboratory of Molecular Neurobiology of Ministry of Education and the Collaborative Innovation Center for Brain Science, Naval Medical University, Shanghai 200433, China
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16
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Michel N, Young HMR, Atkin ND, Arshad U, Al-Humadi R, Singh S, Manukyan A, Gore L, Burbulis IE, Wang YH, McConnell MJ. Transcription-associated DNA DSBs activate p53 during hiPSC-based neurogenesis. Sci Rep 2022; 12:12156. [PMID: 35840793 PMCID: PMC9287420 DOI: 10.1038/s41598-022-16516-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Accepted: 07/11/2022] [Indexed: 11/09/2022] Open
Abstract
Neurons are overproduced during cerebral cortical development. Neural progenitor cells (NPCs) divide rapidly and incur frequent DNA double-strand breaks (DSBs) throughout cortical neurogenesis. Although half of the neurons born during neurodevelopment die, many neurons with inaccurate DNA repair survive leading to brain somatic mosaicism. Recurrent DNA DSBs during neurodevelopment are associated with both gene expression level and gene length. We used imaging flow cytometry and a genome-wide DNA DSB capture approach to quantify and map DNA DSBs during human induced pluripotent stem cell (hiPSC)-based neurogenesis. Reduced p53 signaling was brought about by knockdown (p53KD); p53KD led to elevated DNA DSB burden in neurons that was associated with gene expression level but not gene length in neural progenitor cells (NPCs). Furthermore, DNA DSBs incurred from transcriptional, but not replicative, stress lead to p53 activation in neurotypical NPCs. In p53KD NPCs, DNA DSBs accumulate at transcription start sites of genes that are associated with neurological and psychiatric disorders. These findings add to a growing understanding of how neuronal genome dynamics are engaged by high transcriptional or replicative burden during neurodevelopment.
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Affiliation(s)
- Nadine Michel
- Neuroscience Graduate Program, University of Virginia School of Medicine, 1340 Jefferson Park Avenue, Charlottesville, VA, 22908, USA
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, 1340 Jefferson Park Avenue, Charlottesville, VA, 22908, USA
| | - Heather M Raimer Young
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, 1340 Jefferson Park Avenue, Charlottesville, VA, 22908, USA
| | - Naomi D Atkin
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, 1340 Jefferson Park Avenue, Charlottesville, VA, 22908, USA
| | - Umar Arshad
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, 1340 Jefferson Park Avenue, Charlottesville, VA, 22908, USA
| | - Reem Al-Humadi
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, 1340 Jefferson Park Avenue, Charlottesville, VA, 22908, USA
| | - Sandeep Singh
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, 1340 Jefferson Park Avenue, Charlottesville, VA, 22908, USA
| | - Arkadi Manukyan
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, 1340 Jefferson Park Avenue, Charlottesville, VA, 22908, USA
| | - Lana Gore
- Lieber Institute for Brain Development, 855 N. Wolfe St., Ste. 300, Baltimore, MD, 21205, USA
| | - Ian E Burbulis
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, 1340 Jefferson Park Avenue, Charlottesville, VA, 22908, USA
- Sede de la Patagonia, Facultad de Medicina y Ciencias, Universidad San Sebastián, Puerto Montt, Chile
| | - Yuh-Hwa Wang
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, 1340 Jefferson Park Avenue, Charlottesville, VA, 22908, USA
| | - Michael J McConnell
- Lieber Institute for Brain Development, 855 N. Wolfe St., Ste. 300, Baltimore, MD, 21205, USA.
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17
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Zhang Y, Yang H, Wang L, Zhou H, Zhang G, Xiao Z, Xue X. TOP2A correlates with poor prognosis and affects radioresistance of medulloblastoma. Front Oncol 2022; 12:918959. [PMID: 35912241 PMCID: PMC9337862 DOI: 10.3389/fonc.2022.918959] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Accepted: 06/27/2022] [Indexed: 12/05/2022] Open
Abstract
Radiotherapy remains the standard treatment for medulloblastoma (MB), and the radioresistance contributes to tumor recurrence and poor clinical outcomes. Nuclear DNA topoisomerase II-alpha (TOP2A) is a key catalytic enzyme that initiates DNA replication, and studies have shown that TOP2A is closely related to the therapeutic effects of radiation. In this study, we found that TOP2A was significantly upregulated in MB, and high expression of TOP2A related to poor prognosis of MB patients. Knockdown of TOP2A inhibited MB cell proliferation, migration, and invasion, whereas overexpression of TOP2A enhanced the proliferative and invasive ability of MB cells. Moreover, si-TOP2A transfection in combination with irradiation (IR) significantly reduced the tumorigenicity of MB cells, compared with those transfected with si-TOP2A alone. Cell survival curve analysis revealed that the survival fraction of MB cells was significantly reduced upon TOP2A downregulation and that si-TOP2A-transfected cells had decreased D0, Dq, and SF2 values, indicating that TOP2A knockdown suppresses the resistance to radiotherapy in MB cells. In addition, western blot analysis demonstrated that the activity of Wnt/β-catenin signaling pathway was inhibited after TOP2A downregulation alone or in combination with IR treatment, whereas overexpression of TOP2A exhibited the opposite effects. Gene set enrichment analysis also revealed that Wnt/β-catenin signaling pathway is enriched in TOP2A high-expression phenotypes. Collectively, these data indicate that high expression of TOP2A leads to poor prognosis of MB, and downregulation of TOP2A inhibits the malignant behaviour as well as the radioresistance of MB cells. The Wnt/β-catenin signaling pathway may be involved in the molecular mechanisms of TOP2A mediated reduced tumorigenicity and radioresistance of MB cells.
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Affiliation(s)
- Yufeng Zhang
- Department of Radiotherapy, The Second Hospital of Hebei Medical University, Shijiazhuang, China
| | - Haiyan Yang
- Department of Pathology, The Second Hospital of Hebei Medical University, Shijiazhuang, China
| | - Liwen Wang
- Department of Radiotherapy, The Second Hospital of Hebei Medical University, Shijiazhuang, China
| | - Huandi Zhou
- Department of Radiotherapy, The Second Hospital of Hebei Medical University, Shijiazhuang, China
| | - Ge Zhang
- Department of Radiotherapy, The Second Hospital of Hebei Medical University, Shijiazhuang, China
| | - Zhiqing Xiao
- Department of Radiotherapy, The Second Hospital of Hebei Medical University, Shijiazhuang, China
| | - Xiaoying Xue
- Department of Radiotherapy, The Second Hospital of Hebei Medical University, Shijiazhuang, China
- *Correspondence: Xiaoying Xue,
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Liao M, Yu J. Secondary Leukemia in a Patient With EBV-HLH Carrying Heterozygous STXBP2 Variant. J Pediatr Hematol Oncol 2022; 44:e526-e528. [PMID: 33661178 DOI: 10.1097/mph.0000000000002141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/28/2020] [Accepted: 02/09/2021] [Indexed: 11/25/2022]
Abstract
Hemophagocytic lymphohistiocytosis (HLH) is a symptom with severe systemic hyperinflammation. A 26-month-old male presented with Epstein-Barr virus associated HLH with a heterozygous variant of syntaxin-binding protein-2 (STXBP2). Complete remission was achieved with the HLH-2004 protocol, but the disease soon relapsed. Four weeks after re-installing HLH-2004 protocol, HLH was resolved. The cumulative dosage of etoposide was 2100 mg/m2. He developed acute promyelocytic leukemia 17 months later. The patient underwent standard chemotherapy and since remained in complete remission. In conclusion, a regular screening of malignance might be in necessity for the patients harboring gene variants associated with familial HLH.
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Affiliation(s)
- Meiling Liao
- Department of Hematology and Oncology, Chongqing Medical University Affiliated Children's Hospital, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing Key Laboratory of Pediatrics, Chongqing, China
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19
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Pommier Y, Nussenzweig A, Takeda S, Austin C. Human topoisomerases and their roles in genome stability and organization. Nat Rev Mol Cell Biol 2022; 23:407-427. [PMID: 35228717 PMCID: PMC8883456 DOI: 10.1038/s41580-022-00452-3] [Citation(s) in RCA: 121] [Impact Index Per Article: 60.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/06/2022] [Indexed: 12/15/2022]
Abstract
Human topoisomerases comprise a family of six enzymes: two type IB (TOP1 and mitochondrial TOP1 (TOP1MT), two type IIA (TOP2A and TOP2B) and two type IA (TOP3A and TOP3B) topoisomerases. In this Review, we discuss their biochemistry and their roles in transcription, DNA replication and chromatin remodelling, and highlight the recent progress made in understanding TOP3A and TOP3B. Because of recent advances in elucidating the high-order organization of the genome through chromatin loops and topologically associating domains (TADs), we integrate the functions of topoisomerases with genome organization. We also discuss the physiological and pathological formation of irreversible topoisomerase cleavage complexes (TOPccs) as they generate topoisomerase DNA–protein crosslinks (TOP-DPCs) coupled with DNA breaks. We discuss the expanding number of redundant pathways that repair TOP-DPCs, and the defects in those pathways, which are increasingly recognized as source of genomic damage leading to neurological diseases and cancer. Topoisomerases have essential roles in transcription, DNA replication, chromatin remodelling and, as recently revealed, 3D genome organization. However, topoisomerases also generate DNA–protein crosslinks coupled with DNA breaks, which are increasingly recognized as a source of disease-causing genomic damage.
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20
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Bernstein C. DNA Methylation and Establishing Memory. Epigenet Insights 2022; 15:25168657211072499. [PMID: 35098021 PMCID: PMC8793415 DOI: 10.1177/25168657211072499] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2021] [Accepted: 12/17/2021] [Indexed: 11/30/2022] Open
Abstract
A single event can cause a life-long memory. Memories physically reside in neurons, and changes in neuronal gene expression are considered to be central to memory. Early models proposed that specific DNA methylations of cytosines in neuronal DNA encode memories in a stable biochemical form. This review describes recent research that elucidates the molecular mechanisms used by the mammalian brain to form DNA methylcytosine encoded memories. For example, neuron activation initiates cytosine demethylation by stimulating DNA topoisomerase II beta (TOP2B) protein to make a temporary DNA double-strand break (repaired within about 2 hours) at a promoter of an immediate early gene, EGR1, allowing expression of this gene. The EGR1 proteins then recruit methylcytosine dioxygenase TET1 proteins to initiate demethylation at several hundred genes, facilitating expression of those genes. Initiation of demethylation of cytosine also occurs when OGG1 localizes at oxidized guanine in a methylated CpG site and recruits TET1 for initiation of demethylation at that site. DNMT3A2 is another immediate early gene upregulated by synaptic activity. DNMT3A2 protein catalyzes de novo DNA methylations. These several mechanisms convert external experiences into DNA methylations and initiated demethylations of neuronal DNA cytosines, causing changes in gene expression that are the basis of long-term memories.
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Affiliation(s)
- Carol Bernstein
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, AZ, USA
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21
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Atkin ND, Raimer HM, Wang Z, Zang C, Wang YH. Assessing acute myeloid leukemia susceptibility in rearrangement-driven patients by DNA breakage at topoisomerase II and CCCTC-binding factor/cohesin binding sites. Genes Chromosomes Cancer 2021; 60:808-821. [PMID: 34405474 PMCID: PMC8511143 DOI: 10.1002/gcc.22993] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2021] [Revised: 08/12/2021] [Accepted: 08/14/2021] [Indexed: 12/29/2022] Open
Abstract
An initiating DNA double strand break (DSB) event precedes the formation of cancer-driven chromosomal abnormalities, such as gene rearrangements. Therefore, measuring DNA breaks at rearrangement-participating regions can provide a unique tool to identify and characterize susceptible individuals. Here, we developed a highly sensitive and low-input DNA break mapping method, the first of its kind for patient samples. We then measured genome-wide DNA breakage in normal cells of acute myeloid leukemia (AML) patients with KMT2A (previously MLL) rearrangements, compared to that of nonfusion AML individuals, as a means to evaluate individual susceptibility to gene rearrangements. DNA breakage at the KMT2A gene region was significantly greater in fusion-driven remission individuals, as compared to nonfusion individuals. Moreover, we identified select topoisomerase II (TOP2)-sensitive and CCCTC-binding factor (CTCF)/cohesin-binding sites with preferential DNA breakage in fusion-driven patients. Importantly, measuring DSBs at these sites, in addition to the KMT2A gene region, provided greater predictive power when assessing individual break susceptibility. We also demonstrated that low-dose etoposide exposure further elevated DNA breakage at these regions in fusion-driven AML patients, but not in nonfusion patients, indicating that these sites are preferentially sensitive to TOP2 activity in fusion-driven AML patients. These results support that mapping of DSBs in patients enables discovery of novel break-prone regions and monitoring of individuals susceptible to chromosomal abnormalities, and thus cancer. This will build the foundation for early detection of cancer-susceptible individuals, as well as those preferentially susceptible to therapy-related malignancies caused by treatment with TOP2 poisons.
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MESH Headings
- Binding Sites/genetics
- CCCTC-Binding Factor/blood
- CCCTC-Binding Factor/genetics
- Cell Cycle Proteins/blood
- Cell Cycle Proteins/genetics
- Chondroitin Sulfate Proteoglycans/blood
- Chondroitin Sulfate Proteoglycans/genetics
- Chromosomal Proteins, Non-Histone/blood
- Chromosomal Proteins, Non-Histone/genetics
- Chromosome Aberrations
- DNA Breaks, Double-Stranded/drug effects
- DNA Repair/genetics
- DNA Topoisomerases, Type II/blood
- DNA Topoisomerases, Type II/genetics
- DNA-Binding Proteins/blood
- DNA-Binding Proteins/genetics
- Etoposide/pharmacology
- Female
- Gene Rearrangement/genetics
- Genome, Human/genetics
- HeLa Cells
- Histone-Lysine N-Methyltransferase/blood
- Histone-Lysine N-Methyltransferase/genetics
- Humans
- Leukemia, Myeloid, Acute/blood
- Leukemia, Myeloid, Acute/genetics
- Leukemia, Myeloid, Acute/pathology
- Male
- Myeloid-Lymphoid Leukemia Protein/blood
- Myeloid-Lymphoid Leukemia Protein/genetics
- Oncogene Proteins, Fusion/genetics
- Poly-ADP-Ribose Binding Proteins/blood
- Poly-ADP-Ribose Binding Proteins/genetics
- Cohesins
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Affiliation(s)
- Naomi D. Atkin
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, Virginia, 22908-0733, USA
| | - Heather M. Raimer
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, Virginia, 22908-0733, USA
| | - Zhenjia Wang
- Center for Public Health Genomics, University of Virginia School of Medicine, Charlottesville, Virginia, 22908-0733, USA
| | - Chongzhi Zang
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, Virginia, 22908-0733, USA
- Center for Public Health Genomics, University of Virginia School of Medicine, Charlottesville, Virginia, 22908-0733, USA
- Department of Public Health Sciences, University of Virginia School of Medicine, Charlottesville, Virginia, 22908-0733, USA
| | - Yuh-Hwa Wang
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, Virginia, 22908-0733, USA
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22
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Camarillo R, Jimeno S, Huertas P. The Effect of Atypical Nucleic Acids Structures in DNA Double Strand Break Repair: A Tale of R-loops and G-Quadruplexes. Front Genet 2021; 12:742434. [PMID: 34691154 PMCID: PMC8531813 DOI: 10.3389/fgene.2021.742434] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Accepted: 09/28/2021] [Indexed: 01/08/2023] Open
Abstract
The fine tuning of the DNA double strand break repair pathway choice relies on different regulatory layers that respond to environmental and local cues. Among them, the presence of non-canonical nucleic acids structures seems to create challenges for the repair of nearby DNA double strand breaks. In this review, we focus on the recently published effects of G-quadruplexes and R-loops on DNA end resection and homologous recombination. Finally, we hypothesized a connection between those two atypical DNA structures in inhibiting the DNA end resection step of HR.
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Affiliation(s)
- Rosa Camarillo
- Departamento de Genética, Universidad de Sevilla, Sevilla, Spain.,Centro Andaluz de Biología Molecular y Medicina Regenerativa-CABIMER, Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, Sevilla, Spain
| | - Sonia Jimeno
- Departamento de Genética, Universidad de Sevilla, Sevilla, Spain.,Centro Andaluz de Biología Molecular y Medicina Regenerativa-CABIMER, Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, Sevilla, Spain
| | - Pablo Huertas
- Departamento de Genética, Universidad de Sevilla, Sevilla, Spain.,Centro Andaluz de Biología Molecular y Medicina Regenerativa-CABIMER, Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, Sevilla, Spain
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23
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Zell J, Duskova K, Chouh L, Bossaert M, Chéron N, Granzhan A, Britton S, Monchaud D. Dual targeting of higher-order DNA structures by azacryptands induces DNA junction-mediated DNA damage in cancer cells. Nucleic Acids Res 2021; 49:10275-10288. [PMID: 34551430 PMCID: PMC8501980 DOI: 10.1093/nar/gkab796] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 08/16/2021] [Accepted: 09/01/2021] [Indexed: 12/11/2022] Open
Abstract
DNA is intrinsically dynamic and folds transiently into alternative higher-order structures such as G-quadruplexes (G4s) and three-way DNA junctions (TWJs). G4s and TWJs can be stabilised by small molecules (ligands) that have high chemotherapeutic potential, either as standalone DNA damaging agents or combined in synthetic lethality strategies. While previous approaches have claimed to use ligands that specifically target either G4s or TWJs, we report here on a new approach in which ligands targeting both TWJs and G4s in vitro demonstrate cellular effects distinct from that of G4 ligands, and attributable to TWJ targeting. The DNA binding modes of these new, dual TWJ-/G4-ligands were studied by a panel of in vitro methods and theoretical simulations, and their cellular properties by extensive cell-based assays. We show here that cytotoxic activity of TWJ-/G4-ligands is mitigated by the DNA damage response (DDR) and DNA topoisomerase 2 (TOP2), making them different from typical G4-ligands, and implying a pivotal role of TWJs in cells. We designed and used a clickable ligand, TrisNP-α, to provide unique insights into the TWJ landscape in cells and its modulation upon co-treatments. This wealth of data was exploited to design an efficient synthetic lethality strategy combining dual ligands with clinically relevant DDR inhibitors.
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Affiliation(s)
- Joanna Zell
- Institut de Chimie Moléculaire de l’Université de Bourgogne (ICMUB), CNRS UMR 6302, UBFC Dijon, 21078 Dijon, France
| | - Katerina Duskova
- Institut de Chimie Moléculaire de l’Université de Bourgogne (ICMUB), CNRS UMR 6302, UBFC Dijon, 21078 Dijon, France
| | - Leïla Chouh
- Institut Curie, CNRS UMR 9187, INSERM U1196, PSL Research University, 91405 Orsay, France
- Université Paris Saclay, CNRS UMR 9187, INSERM U1196, 91405 Orsay, France
| | - Madeleine Bossaert
- Institut de Pharmacologie et de Biologie Structurale (IPBS), CNRS UMR 5089, Université de Toulouse, UPS, Équipe labellisée la Ligue Contre le Cancer, 31077 Toulouse, France
| | - Nicolas Chéron
- Pasteur, Département de chimie, École Normale Supérieure (ENS), CNRS UMR8640, PSL Research University, Sorbonne Université, 75005 Paris, France
| | - Anton Granzhan
- Institut Curie, CNRS UMR 9187, INSERM U1196, PSL Research University, 91405 Orsay, France
- Université Paris Saclay, CNRS UMR 9187, INSERM U1196, 91405 Orsay, France
| | - Sébastien Britton
- Institut de Pharmacologie et de Biologie Structurale (IPBS), CNRS UMR 5089, Université de Toulouse, UPS, Équipe labellisée la Ligue Contre le Cancer, 31077 Toulouse, France
| | - David Monchaud
- Institut de Chimie Moléculaire de l’Université de Bourgogne (ICMUB), CNRS UMR 6302, UBFC Dijon, 21078 Dijon, France
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24
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Zhang W, Gou P, Dupret JM, Chomienne C, Rodrigues-Lima F. Etoposide, an anticancer drug involved in therapy-related secondary leukemia: Enzymes at play. Transl Oncol 2021; 14:101169. [PMID: 34243013 PMCID: PMC8273223 DOI: 10.1016/j.tranon.2021.101169] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Accepted: 06/29/2021] [Indexed: 01/13/2023] Open
Abstract
Etoposide is a semi-synthetic glycoside derivative of podophyllotoxin, also known as VP-16. It is a widely used anticancer medicine in clinics. Unfortunately, high doses or long-term etoposide treatment can induce therapy-related leukemia. The mechanism by which etoposide induces secondary hematopoietic malignancies is still unclear. In this article, we review the potential mechanisms of etoposide induced therapy-related leukemia. Etoposide related leukemogenesis is known to depend on reactive oxidative metabolites of etoposide, notably etoposide quinone, which interacts with cellular proteins such as topoisomerases II (TOP2), CREB-binding protein (CREBBP), and T-Cell Protein Tyrosine Phosphatase (TCPTP). CYP3A4 and CYP3A5 metabolize etoposide to etoposide catechol, which readily oxidizes to etoposide quinone. As a poison of TOP2 enzymes, etoposide and its metabolites induce DNA double-stranded breaks (DSB), and the accumulation of DSB triggers cell apoptosis. If the cell survives, the DSB gives rise to the likelihood of faulty DNA repair events. The gene translocation could occur in mixed-lineage leukemia (MLL) gene, which is well-known in leukemogenesis. Recently, studies have revealed that etoposide metabolites, especially etoposide quinone, can covalently bind to cysteines residues of CREBBP and TCPTP enzymes, . This leads to enzyme inhibition and further affects histone acetylation and phosphorylation of the JAK-STAT pathway, thus putatively altering the proliferation and differentiation of hematopoietic stem cells (HSC). In brief, current studies suggest that etoposide and its metabolites contribute to etoposide therapy-related leukemia through TOP2 mediated DSB and impairs specific enzyme activity, such as CREBBP and TCPTP.
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Affiliation(s)
- Wenchao Zhang
- Université de Paris, BFA, UMR 8251, CNRS, Paris F-75013, France.
| | - Panhong Gou
- Inserm UMR-S1131, Université de Paris, IRSL, Hôpital Saint-Louis, Paris, France
| | | | - Christine Chomienne
- Inserm UMR-S1131, Université de Paris, IRSL, Hôpital Saint-Louis, Paris, France; Service de Biologie Cellulaire, Assistance Publique des Hôpitaux de Paris (AP-HP), Hôpital Saint Louis, Paris, France
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25
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Bossaert M, Pipier A, Riou JF, Noirot C, Nguyên LT, Serre RF, Bouchez O, Defrancq E, Calsou P, Britton S, Gomez D. Transcription-associated topoisomerase 2α (TOP2A) activity is a major effector of cytotoxicity induced by G-quadruplex ligands. eLife 2021; 10:65184. [PMID: 34180392 PMCID: PMC8279764 DOI: 10.7554/elife.65184] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Accepted: 06/16/2021] [Indexed: 12/11/2022] Open
Abstract
G-quadruplexes (G4) are non-canonical DNA structures found in the genome of most species including human. Small molecules stabilizing these structures, called G4 ligands, have been identified and, for some of them, shown to induce cytotoxic DNA double-strand breaks. Through the use of an unbiased genetic approach, we identify here topoisomerase 2α (TOP2A) as a major effector of cytotoxicity induced by two clastogenic G4 ligands, pyridostatin and CX-5461, the latter molecule currently undergoing phase I/II clinical trials in oncology. We show that both TOP2 activity and transcription account for DNA break production following G4 ligand treatments. In contrast, clastogenic activity of these G4 ligands is countered by topoisomerase 1 (TOP1), which limits co-transcriptional G4 formation, and by factors promoting transcriptional elongation. Altogether our results support that clastogenic G4 ligands act as DNA structure-driven TOP2 poisons at transcribed regions bearing G4 structures.
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Affiliation(s)
- Madeleine Bossaert
- Institut de Pharmacologie et Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France.,Equipe Labellisée Ligue Contre le Cancer 2018, Toulouse, France
| | - Angélique Pipier
- Institut de Pharmacologie et Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France.,Equipe Labellisée Ligue Contre le Cancer 2018, Toulouse, France
| | - Jean-Francois Riou
- Structure et Instabilité des Génomes, Muséum National d'Histoire Naturelle, CNRS, INSERM, Paris, France
| | - Céline Noirot
- INRAE, UR 875, Unité de Mathématique et Informatique Appliquées, Genotoul Bioinfo, Castanet-Tolosan, France
| | - Linh-Trang Nguyên
- Institut de Pharmacologie et Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France
| | | | - Olivier Bouchez
- INRAE, US 1426, GeT-PlaGe, Genotoul, Castanet-Tolosan, France
| | - Eric Defrancq
- Département de Chimie Moléculaire, UMR CNRS 5250, Université Grenoble Alpes, Grenoble, France
| | - Patrick Calsou
- Institut de Pharmacologie et Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France.,Equipe Labellisée Ligue Contre le Cancer 2018, Toulouse, France
| | - Sébastien Britton
- Institut de Pharmacologie et Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France.,Equipe Labellisée Ligue Contre le Cancer 2018, Toulouse, France
| | - Dennis Gomez
- Institut de Pharmacologie et Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France.,Equipe Labellisée Ligue Contre le Cancer 2018, Toulouse, France
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26
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Role of Stress-Survival Pathways and Transcriptomic Alterations in Progression of Colorectal Cancer: A Health Disparities Perspective. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:ijerph18115525. [PMID: 34063993 PMCID: PMC8196775 DOI: 10.3390/ijerph18115525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 05/07/2021] [Accepted: 05/19/2021] [Indexed: 12/09/2022]
Abstract
Every year, more than a million individuals are diagnosed with colorectal cancer (CRC) across the world. Certain lifestyle and genetic factors are known to drive the high incidence and mortality rates in some groups of individuals. The presence of enormous amounts of reactive oxygen species is implicated for the on-set and carcinogenesis, and oxidant scavengers are thought to be important in CRC therapy. In this review, we focus on the ethnicity-based CRC disparities in the U.S., the negative effects of oxidative stress and apoptosis, and gene regulation in CRC carcinogenesis. We also highlight the use of antioxidants for CRC treatment, along with screening for certain regulatory genetic elements and oxidative stress indicators as potential biomarkers to determine the CRC risk and progression.
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27
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Walker CR, Scally A, De Maio N, Goldman N. Short-range template switching in great ape genomes explored using pair hidden Markov models. PLoS Genet 2021; 17:e1009221. [PMID: 33651813 PMCID: PMC7954356 DOI: 10.1371/journal.pgen.1009221] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 03/12/2021] [Accepted: 02/10/2021] [Indexed: 12/14/2022] Open
Abstract
Many complex genomic rearrangements arise through template switch errors, which occur in DNA replication when there is a transient polymerase switch to an alternate template nearby in three-dimensional space. While typically investigated at kilobase-to-megabase scales, the genomic and evolutionary consequences of this mutational process are not well characterised at smaller scales, where they are often interpreted as clusters of independent substitutions, insertions and deletions. Here we present an improved statistical approach using pair hidden Markov models, and use it to detect and describe short-range template switches underlying clusters of mutations in the multi-way alignment of hominid genomes. Using robust statistics derived from evolutionary genomic simulations, we show that template switch events have been widespread in the evolution of the great apes’ genomes and provide a parsimonious explanation for the presence of many complex mutation clusters in their phylogenetic context. Larger-scale mechanisms of genome rearrangement are typically associated with structural features around breakpoints, and accordingly we show that atypical patterns of secondary structure formation and DNA bending are present at the initial template switch loci. Our methods improve on previous non-probabilistic approaches for computational detection of template switch mutations, allowing the statistical significance of events to be assessed. By specifying realistic evolutionary parameters based on the genomes and taxa involved, our methods can be readily adapted to other intra- or inter-species comparisons. DNA replication is an imperfect process which causes the mutations that give rise to genetic diversity during the evolution of genomes. While many mutations are independent, single-nucleotide substitutions or small insertions and deletions, some mutations arise as nonindependent clusters of substitutions and larger scale chromosomal rearrangements. Large-scale rearrangements (also called structural variants) in particular can have a profound impact on genome evolution and contribute to both germline and somatic disease in humans. The replication-based mechanisms underlying structural variation typically involve a polymerase switch event in which a large segment of DNA is copied using a template from an alternate location in the genome. Methods for identifying these template switch mutations lack the power to detect smaller scale rearrangements which can arise through the same replication-based pathways. Here we outline a model which can detect and assess the statistical significance of such small-scale template switches within their evolutionary context. We show that these events are widespread in the evolution of great apes and that the genomic features associated with these small-scale rearrangements are similar to those of large-scale structural variants.
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Affiliation(s)
- Conor R. Walker
- European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL-EBI), Wellcome Genome Campus, Hinxton, United Kingdom
- Department of Genetics, University of Cambridge, Cambridge, United Kingdom
| | - Aylwyn Scally
- Department of Genetics, University of Cambridge, Cambridge, United Kingdom
| | - Nicola De Maio
- European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL-EBI), Wellcome Genome Campus, Hinxton, United Kingdom
| | - Nick Goldman
- European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL-EBI), Wellcome Genome Campus, Hinxton, United Kingdom
- * E-mail:
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28
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Alternative DNA Structures In Vivo: Molecular Evidence and Remaining Questions. Microbiol Mol Biol Rev 2020; 85:85/1/e00110-20. [PMID: 33361270 DOI: 10.1128/mmbr.00110-20] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Duplex DNA naturally folds into a right-handed double helix in physiological conditions. Some sequences of unusual base composition may nevertheless form alternative structures, as was shown for many repeated sequences in vitro However, evidence for the formation of noncanonical structures in living cells is difficult to gather. It mainly relies on genetic assays demonstrating their function in vivo or through genetic instability reflecting particular properties of such structures. Efforts were made to reveal their existence directly in a living cell, mainly by generating antibodies specific to secondary structures or using chemical ligands selected for their affinity to these structures. Among secondary structure-forming DNAs are G-quadruplexes, human fragile sites containing minisatellites, AT-rich regions, inverted repeats able to form cruciform structures, hairpin-forming CAG/CTG triplet repeats, and triple helices formed by homopurine-homopyrimidine GAA/TTC trinucleotide repeats. Many of these alternative structures are involved in human pathologies, such as neurological or developmental disorders, as in the case of trinucleotide repeats, or cancers triggered by translocations linked to fragile sites. This review will discuss and highlight evidence supporting the formation of alternative DNA structures in vivo and will emphasize the role of the mismatch repair machinery in binding mispaired DNA duplexes, triggering genetic instability.
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