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Nassour J, Przetocka S, Karlseder J. Telomeres as hotspots for innate immunity and inflammation. DNA Repair (Amst) 2024; 133:103591. [PMID: 37951043 PMCID: PMC10842095 DOI: 10.1016/j.dnarep.2023.103591] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Revised: 10/05/2023] [Accepted: 10/24/2023] [Indexed: 11/13/2023]
Abstract
Aging is marked by the gradual accumulation of deleterious changes that disrupt organ function, creating an altered physiological state that is permissive for the onset of prevalent human diseases. While the exact mechanisms governing aging remain a subject of ongoing research, there are several cellular and molecular hallmarks that contribute to this biological process. This review focuses on two factors, namely telomere dysfunction and inflammation, which have emerged as crucial contributors to the aging process. We aim to discuss the mechanistic connections between these two distinct hallmarks and provide compelling evidence highlighting the loss of telomere protection as a driver of pro-inflammatory states associated with aging. By reevaluating the interplay between telomeres, innate immunity, and inflammation, we present novel perspectives on the etiology of aging and its associated diseases.
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Affiliation(s)
- Joe Nassour
- Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, 12801 E. 17th Ave, Aurora, CO 80045, USA; The Salk Institute for Biological Studies, 10010 North Torrey Pines Rd, La Jolla, CA 92037, USA
| | - Sara Przetocka
- The Salk Institute for Biological Studies, 10010 North Torrey Pines Rd, La Jolla, CA 92037, USA
| | - Jan Karlseder
- The Salk Institute for Biological Studies, 10010 North Torrey Pines Rd, La Jolla, CA 92037, USA.
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2
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Rajendraprasad G, Rodriguez-Calado S, Barisic M. SiR-DNA/SiR-Hoechst-induced chromosome entanglement generates severe anaphase bridges and DNA damage. Life Sci Alliance 2023; 6:e202302260. [PMID: 37726128 PMCID: PMC10509460 DOI: 10.26508/lsa.202302260] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2023] [Revised: 09/07/2023] [Accepted: 09/07/2023] [Indexed: 09/21/2023] Open
Abstract
SiR-DNA/SiR-Hoechst is a far-red fluorescent DNA probe that is routinely used for live-cell imaging of cell nuclei in interphase and chromosomes during mitosis. Despite being reported to induce DNA damage, SiR-DNA has been used in more than 300 research articles, covering topics like mitosis, chromatin biology, cancer research, cytoskeletal research, and DNA damage response. Here, we used live-cell imaging to perform a comprehensive analysis of the effects of SiR-DNA on mitosis of four human cell lines (RPE-1, DLD-1, HeLa, and U2OS). We report a dose-, time-, and light-dependent effect of SiR-DNA on chromosome segregation. We found that, upon the exposure to light during imaging, nanomolar concentrations of SiR-DNA induce non-centromeric chromosome entanglement that severely impairs sister chromatid segregation and spindle elongation during anaphase. This causes DNA damage that is passed forward to the following cell cycle, thereby having a detrimental effect on genome integrity. Our findings highlight the drawbacks in using SiR-DNA for investigation of late mitotic events and DNA damage-related topics and urge the use of alternative labeling strategies to study these processes.
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Affiliation(s)
| | | | - Marin Barisic
- Cell Division and Cytoskeleton, Danish Cancer Institute, Copenhagen, Denmark
- Department of Cellular and Molecular Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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3
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Bao C, Tourdot RW, Brunette GJ, Stewart C, Sun L, Baba H, Watanabe M, Agoston AT, Jajoo K, Davison JM, Nason KS, Getz G, Wang KK, Imamura Y, Odze R, Bass AJ, Stachler MD, Zhang CZ. Genomic signatures of past and present chromosomal instability in Barrett's esophagus and early esophageal adenocarcinoma. Nat Commun 2023; 14:6203. [PMID: 37794034 PMCID: PMC10550953 DOI: 10.1038/s41467-023-41805-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Accepted: 09/18/2023] [Indexed: 10/06/2023] Open
Abstract
The progression of precancerous lesions to malignancy is often accompanied by increasing complexity of chromosomal alterations but how these alterations arise is poorly understood. Here we perform haplotype-specific analysis of chromosomal copy-number evolution in the progression of Barrett's esophagus (BE) to esophageal adenocarcinoma (EAC) on multiregional whole-genome sequencing data of BE with dysplasia and microscopic EAC foci. We identify distinct patterns of copy-number evolution indicating multigenerational chromosomal instability that is initiated by cell division errors but propagated only after p53 loss. While abnormal mitosis, including whole-genome duplication, underlies chromosomal copy-number changes, segmental alterations display signatures of successive breakage-fusion-bridge cycles and chromothripsis of unstable dicentric chromosomes. Our analysis elucidates how multigenerational chromosomal instability generates copy-number variation in BE cells, precipitates complex alterations including DNA amplifications, and promotes their independent clonal expansion and transformation. In particular, we suggest sloping copy-number variation as a signature of ongoing chromosomal instability that precedes copy-number complexity. These findings suggest copy-number heterogeneity in advanced cancers originates from chromosomal instability in precancerous cells and such instability may be identified from the presence of sloping copy-number variation in bulk sequencing data.
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Affiliation(s)
- Chunyang Bao
- Department of Medical Oncology, Dana-Farber Cancer Institute, 450 Brookline Ave, Boston, MA, 02215, USA
- Department of Data Science, Dana-Farber Cancer Institute, 450 Brookline Ave, Boston, MA, 02215, USA
- Department of Pathology, Brigham and Women's Hospital, 75 Francis St, Boston, MA, 02115, USA
- Cancer Program, Broad Institute of MIT and Harvard, 415 Main St, Cambridge, MA, 02142, USA
| | - Richard W Tourdot
- Department of Data Science, Dana-Farber Cancer Institute, 450 Brookline Ave, Boston, MA, 02215, USA
- Cancer Program, Broad Institute of MIT and Harvard, 415 Main St, Cambridge, MA, 02142, USA
- Department of Biomedical Informatics, Blavatnik Institute of Harvard Medical School, 10 Shattuck St, Boston, MA, 02115, USA
| | - Gregory J Brunette
- Department of Data Science, Dana-Farber Cancer Institute, 450 Brookline Ave, Boston, MA, 02215, USA
- Department of Biomedical Informatics, Blavatnik Institute of Harvard Medical School, 10 Shattuck St, Boston, MA, 02115, USA
| | - Chip Stewart
- Cancer Program, Broad Institute of MIT and Harvard, 415 Main St, Cambridge, MA, 02142, USA
| | - Lili Sun
- Department of Data Science, Dana-Farber Cancer Institute, 450 Brookline Ave, Boston, MA, 02215, USA
- Single-Cell Sequencing Program, Dana-Farber Cancer Institute, 450 Brookline Ave, Boston, MA, 02215, USA
| | - Hideo Baba
- Department of Gastroenterological Surgery, Graduate School of Medical Sciences, Kumamoto University, 2 Chome-40-1 Kurokami, Chuo Ward, Kumamoto, Japan
| | - Masayuki Watanabe
- Department of Gastroenterological Surgery, Cancer Institute Hospital of Japanese Foundation of Cancer Research, 3-8-31 Ariake, Koto, Tokyo, Japan
| | - Agoston T Agoston
- Department of Pathology, Brigham and Women's Hospital, 75 Francis St, Boston, MA, 02115, USA
| | - Kunal Jajoo
- Division of Gastroenterology, Department of Medicine, Brigham and Women's Hospital, 75 Francis St, Boston, MA, 02115, USA
| | - Jon M Davison
- Department of Pathology, University of Pittsburgh School of Medicine, 200 Lothrop Street, Pittsburgh, PA, 15213, USA
| | - Katie S Nason
- Department of Surgery, Baystate Medical Center, University of Massachusetts Medical School, 759 Chestnut St, Springfield, MA, 01107, USA
| | - Gad Getz
- Department of Pathology, Brigham and Women's Hospital, 75 Francis St, Boston, MA, 02115, USA
| | - Kenneth K Wang
- Division of Gastroenterology and Hepatology, Mayo Clinic, 200 1st St SW, Rochester, MN, 55905, USA
| | - Yu Imamura
- Department of Gastroenterological Surgery, Cancer Institute Hospital of Japanese Foundation of Cancer Research, 3-8-31 Ariake, Koto, Tokyo, Japan
| | - Robert Odze
- Department of Pathology, Brigham and Women's Hospital, 75 Francis St, Boston, MA, 02115, USA
- Department of Pathology and Lab Medicine, Tufts University School of Medicine, 145 Harrison Ave, Boston, MA, 02111, USA
| | - Adam J Bass
- Department of Medical Oncology, Dana-Farber Cancer Institute, 450 Brookline Ave, Boston, MA, 02215, USA.
- Cancer Program, Broad Institute of MIT and Harvard, 415 Main St, Cambridge, MA, 02142, USA.
- Novartis Institutes for Biomedical Research, Cambridge, MA, USA.
| | - Matthew D Stachler
- Department of Medical Oncology, Dana-Farber Cancer Institute, 450 Brookline Ave, Boston, MA, 02215, USA.
- Department of Pathology, Brigham and Women's Hospital, 75 Francis St, Boston, MA, 02115, USA.
- Cancer Program, Broad Institute of MIT and Harvard, 415 Main St, Cambridge, MA, 02142, USA.
- Department of Pathology, University of California, San Francisco. 513 Parnassus Ave, San Francisco, CA, 94143, USA.
| | - Cheng-Zhong Zhang
- Department of Data Science, Dana-Farber Cancer Institute, 450 Brookline Ave, Boston, MA, 02215, USA.
- Department of Pathology, Brigham and Women's Hospital, 75 Francis St, Boston, MA, 02115, USA.
- Cancer Program, Broad Institute of MIT and Harvard, 415 Main St, Cambridge, MA, 02142, USA.
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4
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Wolf SE, Shalev I. The shelterin protein expansion of telomere dynamics: Linking early life adversity, life history, and the hallmarks of aging. Neurosci Biobehav Rev 2023; 152:105261. [PMID: 37268182 PMCID: PMC10527177 DOI: 10.1016/j.neubiorev.2023.105261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Revised: 04/10/2023] [Accepted: 05/30/2023] [Indexed: 06/04/2023]
Abstract
Aging is characterized by functional decline occurring alongside changes to several hallmarks of aging. One of the hallmarks includes attrition of repeated DNA sequences found at the ends of chromosomes called telomeres. While telomere attrition is linked to morbidity and mortality, whether and how it causally contributes to lifelong rates of functional decline is unclear. In this review, we propose the shelterin-telomere hypothesis of life history, in which telomere-binding shelterin proteins translate telomere attrition into a range of physiological outcomes, the extent of which may be modulated by currently understudied variation in shelterin protein levels. Shelterin proteins may expand the breadth and timing of consequences of telomere attrition, e.g., by translating early life adversity into acceleration of the aging process. We consider how the pleiotropic roles of shelterin proteins provide novel insights into natural variation in physiology, life history, and lifespan. We highlight key open questions that encourage the integrative, organismal study of shelterin proteins that enhances our understanding of the contribution of the telomere system to aging.
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Affiliation(s)
- Sarah E Wolf
- Department of Biobehavioral Health, Penn State University, University Park, PA 16802, USA.
| | - Idan Shalev
- Department of Biobehavioral Health, Penn State University, University Park, PA 16802, USA
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5
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Kuse R, Ishii K. Flexible Attachment and Detachment of Centromeres and Telomeres to and from Chromosomes. Biomolecules 2023; 13:1016. [PMID: 37371596 DOI: 10.3390/biom13061016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Revised: 06/15/2023] [Accepted: 06/18/2023] [Indexed: 06/29/2023] Open
Abstract
Accurate transmission of genomic information across multiple cell divisions and generations, without any losses or errors, is fundamental to all living organisms. To achieve this goal, eukaryotes devised chromosomes. Eukaryotic genomes are represented by multiple linear chromosomes in the nucleus, each carrying a centromere in the middle, a telomere at both ends, and multiple origins of replication along the chromosome arms. Although all three of these DNA elements are indispensable for chromosome function, centromeres and telomeres possess the potential to detach from the original chromosome and attach to new chromosomal positions, as evident from the events of telomere fusion, centromere inactivation, telomere healing, and neocentromere formation. These events seem to occur spontaneously in nature but have not yet been elucidated clearly, because they are relatively infrequent and sometimes detrimental. To address this issue, experimental setups have been developed using model organisms such as yeast. In this article, we review some of the key experiments that provide clues as to the extent to which these paradoxical and elusive features of chromosomally indispensable elements may become valuable in the natural context.
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Affiliation(s)
- Riku Kuse
- Laboratory of Chromosome Function and Regulation, Graduate School of Engineering, Kochi University of Technology, Kochi 782-8502, Japan
| | - Kojiro Ishii
- Laboratory of Chromosome Function and Regulation, Graduate School of Engineering, Kochi University of Technology, Kochi 782-8502, Japan
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6
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Hill HJ, Bonser D, Golic KG. Dicentric chromosome breakage in Drosophila melanogaster is influenced by pericentric heterochromatin and occurs in nonconserved hotspots. Genetics 2023; 224:iyad052. [PMID: 37010100 PMCID: PMC10213500 DOI: 10.1093/genetics/iyad052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Revised: 10/18/2022] [Accepted: 03/13/2023] [Indexed: 04/04/2023] Open
Abstract
Chromosome breakage plays an important role in the evolution of karyotypes and can produce deleterious effects within a single individual, such as aneuploidy or cancer. Forces that influence how and where chromosomes break are not fully understood. In humans, breakage tends to occur in conserved hotspots called common fragile sites (CFS), especially during replication stress. By following the fate of dicentric chromosomes in Drosophila melanogaster, we find that breakage under tension also tends to occur in specific hotspots. Our experimental approach was to induce sister chromatid exchange in a ring chromosome to generate a dicentric chromosome with a double chromatid bridge. In the following cell division, the dicentric bridges may break. We analyzed the breakage patterns of 3 different ring-X chromosomes. These chromosomes differ by the amount and quality of heterochromatin they carry as well as their genealogical history. For all 3 chromosomes, breakage occurs preferentially in several hotspots. Surprisingly, we found that the hotspot locations are not conserved between the 3 chromosomes: each displays a unique array of breakage hotspots. The lack of hotspot conservation, along with a lack of response to aphidicolin, suggests that these breakage sites are not entirely analogous to CFS and may reveal new mechanisms of chromosome fragility. Additionally, the frequency of dicentric breakage and the durability of each chromosome's spindle attachment vary significantly between the 3 chromosomes and are correlated with the origin of the centromere and the amount of pericentric heterochromatin. We suggest that different centromere strengths could account for this.
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Affiliation(s)
- Hunter J Hill
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112, USA
| | - Danielle Bonser
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112, USA
| | - Kent G Golic
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112, USA
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7
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Chen Y, Qiu Q, She J, Yu J. Extrachromosomal circular DNA in colorectal cancer: biogenesis, function and potential as therapeutic target. Oncogene 2023; 42:941-951. [PMID: 36859558 PMCID: PMC10038807 DOI: 10.1038/s41388-023-02640-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Revised: 02/14/2023] [Accepted: 02/16/2023] [Indexed: 03/03/2023]
Abstract
Extrachromosomal circular DNA (ecDNA) has gained renewed interest since its discovery more than half a century ago, emerging as critical driver of tumor evolution. ecDNA is highly prevalent in many types of cancers, including colorectal cancer (CRC), which is one of the most deadly cancers worldwide. ecDNAs play an essential role in regulating oncogene expression, intratumor heterogeneity, and resistance to therapy independently of canonical chromosomal alterations in CRC. Furthermore, the existence of ecDNAs is attributed to the patient's prognosis, since ecDNA-based oncogene amplification adversely affects clinical outcomes. Recent understanding of ecDNA put an extra layer of complexity in the pathogenesis of CRC. In this review, we will discuss the current understanding on mechanisms of biogenesis, and distinctive features of ecDNA in CRC. In addition, we will examine how ecDNAs mediate oncogene overexpression, gene regulation, and topological interactions with active chromatin, which facilitates genetic heterogeneity, accelerates CRC malignancy, and enhances rapid adaptation to therapy resistance. Finally, we will discuss the potential diagnostic and therapeutic implications of ecDNAs in CRC.
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Affiliation(s)
- Yinnan Chen
- Center for Gut Microbiome Research, Med-X Institute, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, China
- Department of High Talent, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, China
| | - Quanpeng Qiu
- Center for Gut Microbiome Research, Med-X Institute, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, China
- Department of High Talent, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, China
- Department of General Surgery, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, China
| | - Junjun She
- Center for Gut Microbiome Research, Med-X Institute, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, China.
- Department of High Talent, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, China.
- Department of General Surgery, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, China.
| | - Jun Yu
- Center for Gut Microbiome Research, Med-X Institute, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, China.
- Department of High Talent, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, China.
- Institute of Digestive Disease and Department of Medicine and Therapeutics, State Key Laboratory of Digestive Disease, Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong SAR, China.
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8
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Zeng PH, Yin WJ. The cGAS/STING signaling pathway: a cross-talk of infection, senescence and tumors. Cell Cycle 2023; 22:38-56. [PMID: 35946607 PMCID: PMC9769453 DOI: 10.1080/15384101.2022.2109899] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Revised: 06/28/2022] [Accepted: 08/02/2022] [Indexed: 12/24/2022] Open
Abstract
The cGAS/STING signaling pathway is an important part of the cytoplasmic DNA sensor, which can trigger a type I interferon response to microbial infection when pathogenic DNA is detected. However, continuous inhibition of cGAS/STING signaling by viral infection may be an important cause of tumorigenesis. At the same time, recent studies have shown that although the cGAS/STING signaling pathway also plays a core role in anti-tumor immunity and cell senescence, the inflammatory response induced by cGAS/STING signaling will also promote tumorigenesis in different backgrounds. Here, we discuss the role of cGAS/STING in the context of infection, senescence, and tumors, especially with respect to progression, to facilitate a better understanding of the mechanism of the cGAS/STING pathway.
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Affiliation(s)
- Peng-Hui Zeng
- Department of Clinical Laboratory, The First Affiliated Hospital, Hengyang Medical School, University of South China, Hengyang, China
| | - Wen-Jun Yin
- Department of Clinical Laboratory, The First Affiliated Hospital, Hengyang Medical School, University of South China, Hengyang, China
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9
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Metcalfe NB, Olsson M. How telomere dynamics are influenced by the balance between mitochondrial efficiency, reactive oxygen species production and DNA damage. Mol Ecol 2022; 31:6040-6052. [PMID: 34435398 DOI: 10.1111/mec.16150] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Revised: 08/02/2021] [Accepted: 08/23/2021] [Indexed: 01/31/2023]
Abstract
It is well known that oxidative stress is a major cause of DNA damage and telomere attrition. Most endogenous reactive oxygen species (ROS) are produced in the mitochondria, producing a link between mitochondrial function, DNA integrity and telomere dynamics. In this review we will describe how ROS production, rates of damage to telomeric DNA and DNA repair are dynamic processes. The rate of ROS production depends on mitochondrial features such as the level of inner membrane uncoupling and the proportion of time that ATP is actively being produced. However, the efficiency of ATP production (the ATP/O ratio) is positively related to the rate of ROS production, so leading to a trade-off between the body's energy requirements and its need to prevent oxidative stress. Telomeric DNA is especially vulnerable to oxidative damage due to features such as its high guanine content; while repair to damaged telomere regions is possible through a range of mechanisms, these can result in more rapid telomere shortening. There is increasing evidence that mitochondrial efficiency varies over time and with environmental context, as do rates of DNA repair. We argue that telomere dynamics can only be understood by appreciating that the optimal solution to the trade-off between energetic efficiency and telomere protection will differ between individuals and will change over time, depending on resource availability, energetic demands and life history strategy.
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Affiliation(s)
- Neil B Metcalfe
- Institute of Biodiversity, Animal Health & Comparative Medicine, University of Glasgow, Glasgow, UK
| | - Mats Olsson
- Department of Biological and Environmental Sciences, University of Gothenburg, Gothenburg, Sweden
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10
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Zhu Y, Gong L, Wei CL. Guilt by association: EcDNA as a mobile transactivator in cancer. Trends Cancer 2022; 8:747-758. [PMID: 35753910 PMCID: PMC9388558 DOI: 10.1016/j.trecan.2022.04.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 04/10/2022] [Accepted: 04/28/2022] [Indexed: 10/17/2022]
Abstract
Extrachromosomal DNA (ecDNA), first described in the 1960s, is emerging as a prevalent but poorly characterized oncogenic alteration in cancer. ecDNA is a reservoir for oncogene amplification and is associated with an aggressive tumor phenotype and poor patient outcome. Despite the long-held knowledge of its existence, little is known about how ecDNA affects tumor cell behavior. Recent data reveal that ecDNA hubs are mobile transcriptional enhancers which can transactivate gene expression through chromatin interactions. Given its prevalence, structural complexity, and unequal segregation into daughter cells, ecDNA can offer selective growth advantages, contribute to intratumor heterogeneity (ITH), and accelerate tumor evolution. Future technology development is expected to transform the current paradigm for studying ecDNA and lead to therapeutic strategies targeting ecDNA vulnerabilities.
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Affiliation(s)
- Yanfen Zhu
- The Jackson Laboratory for Genomic Medicine, Farmington, CT 06032, USA; International Institutes of Medicine, The Fourth Affiliated Hospital, Zhejiang University School of Medicine, Yiwu, Zhejiang 322000, China
| | - Liang Gong
- The Jackson Laboratory for Genomic Medicine, Farmington, CT 06032, USA; Liangzhu Laboratory, Zhejiang University Medical Center, Hangzhou, Zhejiang 311121, China
| | - Chia-Lin Wei
- The Jackson Laboratory for Genomic Medicine, Farmington, CT 06032, USA.
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11
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Cleal K, Baird DM. Dysgu: efficient structural variant calling using short or long reads. Nucleic Acids Res 2022; 50:e53. [PMID: 35100420 PMCID: PMC9122538 DOI: 10.1093/nar/gkac039] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Revised: 12/20/2021] [Accepted: 01/24/2022] [Indexed: 12/27/2022] Open
Abstract
Structural variation (SV) plays a fundamental role in genome evolution and can underlie inherited or acquired diseases such as cancer. Long-read sequencing technologies have led to improvements in the characterization of structural variants (SVs), although paired-end sequencing offers better scalability. Here, we present dysgu, which calls SVs or indels using paired-end or long reads. Dysgu detects signals from alignment gaps, discordant and supplementary mappings, and generates consensus contigs, before classifying events using machine learning. Additional SVs are identified by remapping of anomalous sequences. Dysgu outperforms existing state-of-the-art tools using paired-end or long-reads, offering high sensitivity and precision whilst being among the fastest tools to run. We find that combining low coverage paired-end and long-reads is competitive in terms of performance with long-reads at higher coverage values.
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Affiliation(s)
- Kez Cleal
- Division of Cancer and Genetics, School of Medicine, Cardiff University, Heath Park, Cardiff CF14 4XN, UK
| | - Duncan M Baird
- Division of Cancer and Genetics, School of Medicine, Cardiff University, Heath Park, Cardiff CF14 4XN, UK
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12
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Zhu J, Huang Q, Peng X, Luo C, Liu S, Liu Z, Wu X, Luo H. Identification of LncRNA Prognostic Signature Associated With Genomic Instability in Pancreatic Adenocarcinoma. Front Oncol 2022; 12:799475. [PMID: 35433487 PMCID: PMC9012103 DOI: 10.3389/fonc.2022.799475] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Accepted: 02/28/2022] [Indexed: 12/21/2022] Open
Abstract
Background Genomic instability (GI) is a critical feature of cancer which plays a key role in the occurrence and development of pancreatic adenocarcinoma (PAAD). Long non-coding RNA (LncRNA) is an emerging prognostic biomarker because it is involved in regulating GI. Recently, researchers used such GI-related LncRNAs (GILncRNAs) to establish a prognostic signature for patients with cancer and helped in predicting the overall prognosis of the patients. However, it is evident that patients with PAAD still lack such prognostic signature constructed with GILncRNA. Methods The present study screened GILncRNAs from 83 patients with PAAD. Prognosis-related GILncRNAs were identified by univariate Cox regression analysis. The correlation coefficients of these GILncRNAs were obtained by multivariate Cox regression analysis and used to construct a signature. The signature in the present study was then assessed through survival analysis, mutation correlation analysis, independent prognostic analysis, and clinical stratification analysis in the training set and validated in the testing as well as all TCGA set. The current study performed external clinical relevance validation of the signature and validated the effect of AC108134.2 in GILncSig on PAAD using in vitro experiments. Finally, the function of GILncRNA signature (GILncSig) dependent on Gene Ontology enrichment analysis was explored and chemotherapeutic drug sensitivity analysis was also performed. Results Results of the present study found that a total of 409 GILncRNAs were identified, 5 of which constituted the prognostic risk signature in this study, namely, AC095057.3, AC108134.2, AC124798.1, AL606834.1, and AC104695.4. It was found that the signature of the present study was better than others in predicting the overall survival and applied to patients with PAAD of all ages, genders, and tumor grades. Further, it was noted that the signature of the current study in the GSE102238, was correlated with tumor length, and tumor stage of patients with PAAD. In vitro, functional experiments were used in the present study to validate that AC108134.2 is associated with PAAD genomic instability and progression. Notably, results of the pRRophetic analysis in the current study showed that the high-risk group possessed reverse characteristics and was sensitive to chemotherapy. Conclusions In conclusion, it was evident that the GILncSig used in the present study has good prognostic performance. Therefore, the signature may become a potential sensitive biological indicator of PAAD chemotherapy, which may help in clinical decision-making and management of patients with cancer.
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Affiliation(s)
- Jinfeng Zhu
- Department of General Surgery, The Second Affiliated Hospital of Nanchang University, Nanchang, China.,Jiangxi Province Key Laboratory of Molecular Medicine, Nanchang, China
| | - Qian Huang
- Department of General Practice, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Xingyu Peng
- Department of General Surgery, The Second Affiliated Hospital of Nanchang University, Nanchang, China.,Jiangxi Province Key Laboratory of Molecular Medicine, Nanchang, China
| | - Chen Luo
- Department of General Surgery, The Second Affiliated Hospital of Nanchang University, Nanchang, China
| | - Sicheng Liu
- Department of General Surgery, The Second Affiliated Hospital of Nanchang University, Nanchang, China
| | - Zitao Liu
- Department of General Surgery, The Second Affiliated Hospital of Nanchang University, Nanchang, China
| | - Xun Wu
- Department of General Surgery, The Second Affiliated Hospital of Nanchang University, Nanchang, China
| | - Hongliang Luo
- Department of General Surgery, The Second Affiliated Hospital of Nanchang University, Nanchang, China
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13
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Zhang CZ, Pellman D. Cancer Genomic Rearrangements and Copy Number Alterations from Errors in Cell Division. ANNUAL REVIEW OF CANCER BIOLOGY 2022. [DOI: 10.1146/annurev-cancerbio-070620-094029] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Analysis of cancer genomes has shown that a large fraction of chromosomal changes originate from catastrophic events including whole-genome duplication, chromothripsis, breakage-fusion-bridge cycles, and chromoplexy. Through sophisticated computational analysis of cancer genomes and experimental recapitulation of these catastrophic alterations, we have gained significant insights into the origin, mechanism, and evolutionary dynamics of cancer genome complexity. In this review, we summarize this progress and survey the major unresolved questions, with particular emphasis on the relative contributions of chromosome fragmentation and DNA replication errors to complex chromosomal alterations.
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Affiliation(s)
- Cheng-Zhong Zhang
- Department of Data Science, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
- Department of Biomedical Informatics, Blavatnik Institute of Harvard Medical School, Boston, Massachusetts, USA
- Cancer Program, Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | - David Pellman
- Cancer Program, Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
- Howard Hughes Medical Institute, Chevy Chase, Maryland, USA
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
- Department of Cell Biology, Blavatnik Institute of Harvard Medical School, Boston, Massachusetts, USA
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14
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Enhanced radiosensitivity by 6-thio-dG via increasing telomere dysfunction and ataxia telangiectasia mutated inhibition in non-small cell lung cancer. RADIATION MEDICINE AND PROTECTION 2022. [DOI: 10.1016/j.radmp.2022.04.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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15
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Vertecchi E, Rizzo A, Salvati E. Telomere Targeting Approaches in Cancer: Beyond Length Maintenance. Int J Mol Sci 2022; 23:ijms23073784. [PMID: 35409143 PMCID: PMC8998427 DOI: 10.3390/ijms23073784] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 03/25/2022] [Accepted: 03/26/2022] [Indexed: 12/19/2022] Open
Abstract
Telomeres are crucial structures that preserve genome stability. Their progressive erosion over numerous DNA duplications determines the senescence of cells and organisms. As telomere length homeostasis is critical for cancer development, nowadays, telomere maintenance mechanisms are established targets in cancer treatment. Besides telomere elongation, telomere dysfunction impinges on intracellular signaling pathways, in particular DNA damage signaling and repair, affecting cancer cell survival and proliferation. This review summarizes and discusses recent findings in anticancer drug development targeting different “telosome” components.
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Affiliation(s)
- Eleonora Vertecchi
- Institute of Molecular Biology and Pathology, National Research Council, Rome, Italy, c/o Department of Biology and Biotechnology, Sapienza University of Rome, Via degli Apuli 4, 00185 Rome, Italy;
| | - Angela Rizzo
- Oncogenomic and Epigenetic Unit, IRCCS Regina Elena National Cancer Institute, Via Elio Chianesi 53, 00144 Rome, Italy;
| | - Erica Salvati
- Institute of Molecular Biology and Pathology, National Research Council, Rome, Italy, c/o Department of Biology and Biotechnology, Sapienza University of Rome, Via degli Apuli 4, 00185 Rome, Italy;
- Correspondence:
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16
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Ferragut Cardoso AP, Banerjee M, Nail AN, Lykoudi A, States JC. miRNA dysregulation is an emerging modulator of genomic instability. Semin Cancer Biol 2021; 76:120-131. [PMID: 33979676 PMCID: PMC8576067 DOI: 10.1016/j.semcancer.2021.05.004] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 04/30/2021] [Accepted: 05/03/2021] [Indexed: 12/12/2022]
Abstract
Genomic instability consists of a range of genetic alterations within the genome that contributes to tumor heterogeneity and drug resistance. It is a well-established characteristic of most cancer cells. Genome instability induction results from defects in DNA damage surveillance mechanisms, mitotic checkpoints and DNA repair machinery. Accumulation of genetic alterations ultimately sets cells towards malignant transformation. Recent studies suggest that miRNAs are key players in mediating genome instability. miRNAs are a class of small RNAs expressed in most somatic tissues and are part of the epigenome. Importantly, in many cancers, miRNA expression is dysregulated. Consequently, this review examines the role of miRNA dysregulation as a causal step for induction of genome instability and subsequent carcinogenesis. We focus specifically on mechanistic studies assessing miRNA(s) and specific subtypes of genome instability or known modes of genome instability. In addition, we provide insight on the existing knowledge gaps within the field and possible ways to address them.
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Affiliation(s)
- Ana P Ferragut Cardoso
- Department of Pharmacology and Toxicology, University of Louisville, Louisville, KY, 40202, USA
| | - Mayukh Banerjee
- Department of Pharmacology and Toxicology, University of Louisville, Louisville, KY, 40202, USA
| | - Alexandra N Nail
- Department of Pharmacology and Toxicology, University of Louisville, Louisville, KY, 40202, USA
| | - Angeliki Lykoudi
- Department of Pharmacology and Toxicology, University of Louisville, Louisville, KY, 40202, USA
| | - J Christopher States
- Department of Pharmacology and Toxicology, University of Louisville, Louisville, KY, 40202, USA.
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17
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Lim S, Kim YJ, Park S, Choi JH, Sung YH, Nishimori K, Kozmik Z, Lee HW, Kim JW. mTORC1-induced retinal progenitor cell overproliferation leads to accelerated mitotic aging and degeneration of descendent Müller glia. eLife 2021; 10:70079. [PMID: 34677125 PMCID: PMC8577849 DOI: 10.7554/elife.70079] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Accepted: 10/17/2021] [Indexed: 01/22/2023] Open
Abstract
Retinal progenitor cells (RPCs) divide in limited numbers to generate the cells comprising vertebrate retina. The molecular mechanism that leads RPC to the division limit, however, remains elusive. Here, we find that the hyperactivation of mechanistic target of rapamycin complex 1 (mTORC1) in an RPC subset by deletion of tuberous sclerosis complex 1 (Tsc1) makes the RPCs arrive at the division limit precociously and produce Müller glia (MG) that degenerate from senescence-associated cell death. We further show the hyperproliferation of Tsc1-deficient RPCs and the degeneration of MG in the mouse retina disappear by concomitant deletion of hypoxia-induced factor 1-alpha (Hif1a), which induces glycolytic gene expression to support mTORC1-induced RPC proliferation. Collectively, our results suggest that, by having mTORC1 constitutively active, an RPC divides and exhausts mitotic capacity faster than neighboring RPCs, and thus produces retinal cells that degenerate with aging-related changes.
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Affiliation(s)
- Soyeon Lim
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, Republic of Korea
| | - You-Joung Kim
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, Republic of Korea
| | - Sooyeon Park
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, Republic of Korea
| | - Ji-Heon Choi
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, Republic of Korea
| | - Young Hoon Sung
- Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, Yonsei, Republic of Korea.,Department of Convergence Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Katsuhiko Nishimori
- Department of Obesity and Internal Inflammation; Bioregulation and Pharmacological Medicine, Fukushima Medical University, Fukushima, Japan
| | - Zbynek Kozmik
- Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
| | - Han-Woong Lee
- Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, Yonsei, Republic of Korea
| | - Jin Woo Kim
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, Republic of Korea
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18
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Bolzán AD. Mutagen-induced telomere instability in human cells. MUTATION RESEARCH-GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2021; 868-869:503387. [PMID: 34454696 DOI: 10.1016/j.mrgentox.2021.503387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 07/13/2021] [Accepted: 07/18/2021] [Indexed: 11/27/2022]
Abstract
Telomere instability is one of the main sources of genome instability and may result from chromosome end loss (due to chromosome breakage at one or both ends) or, more frequently, telomere dysfunction. Dysfunctional telomeres arise when they lose their end-capping function or become critically short, which causes chromosomal termini to behave like a DNA double-strand break. Telomere instability may occur at the chromosomal or at the molecular level, giving rise, respectively, to telomere-related chromosomal aberrations or the loss or modification of any of the components of the telomere (telomere DNA, telomere-associated proteins, or telomere RNA). Since telomeres play a fundamental role in maintaining genome stability, the study of telomere instability in cells exposed to mutagens is of great importance to understand the telomere-driven genomic instability present in those cells. In the present review, we will focus on the current knowledge about telomere instability induced by physical, chemical, and biological mutagens in human cells.
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Affiliation(s)
- Alejandro D Bolzán
- Laboratorio de Citogenética y Mutagénesis, Instituto Multidisciplinario de Biología Celular (IMBICE, CONICET-CICPBA-UNLP), calle 526 y Camino General Belgrano, B1906APO La Plata, Buenos Aires, Argentina; Universidad Nacional de La Plata, Facultad de Ciencias Naturales y Museo, calle 60 y 122, La Plata, Buenos Aires, Argentina.
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19
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Li B, Zhao Y. Regulation of Antigenic Variation by Trypanosoma brucei Telomere Proteins Depends on Their Unique DNA Binding Activities. Pathogens 2021; 10:pathogens10080967. [PMID: 34451431 PMCID: PMC8402208 DOI: 10.3390/pathogens10080967] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 07/22/2021] [Accepted: 07/27/2021] [Indexed: 01/17/2023] Open
Abstract
Trypanosoma brucei causes human African trypanosomiasis and regularly switches its major surface antigen, Variant Surface Glycoprotein (VSG), to evade the host immune response. Such antigenic variation is a key pathogenesis mechanism that enables T. brucei to establish long-term infections. VSG is expressed exclusively from subtelomere loci in a strictly monoallelic manner, and DNA recombination is an important VSG switching pathway. The integrity of telomere and subtelomere structure, maintained by multiple telomere proteins, is essential for T. brucei viability and for regulating the monoallelic VSG expression and VSG switching. Here we will focus on T. brucei TRF and RAP1, two telomere proteins with unique nucleic acid binding activities, and summarize their functions in telomere integrity and stability, VSG switching, and monoallelic VSG expression. Targeting the unique features of TbTRF and TbRAP1′s nucleic acid binding activities to perturb the integrity of telomere structure and disrupt VSG monoallelic expression may serve as potential therapeutic strategy against T. brucei.
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Affiliation(s)
- Bibo Li
- Center for Gene Regulation in Health and Disease, Department of Biological, Geological, and Environmental Sciences, College of Sciences and Health Professions, Cleveland State University, 2121 Euclid Avenue, Cleveland, OH 44115, USA
- Case Comprehensive Cancer Center, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH 44195, USA
- Center for RNA Science and Therapeutics, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA
- Correspondence: (B.L.); (Y.Z.)
| | - Yanxiang Zhao
- Shenzhen Research Institute, The Hong Kong Polytechnic University, Shenzhen, China
- State Key Laboratory of Chemical Biology and Drug Discovery, Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Hong Kong, China
- Correspondence: (B.L.); (Y.Z.)
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20
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Pobiega S, Alibert O, Marcand S. A new assay capturing chromosome fusions shows a protection trade-off at telomeres and NHEJ vulnerability to low-density ionizing radiation. Nucleic Acids Res 2021; 49:6817-6831. [PMID: 34125900 PMCID: PMC8266670 DOI: 10.1093/nar/gkab502] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 03/31/2021] [Accepted: 05/27/2021] [Indexed: 11/14/2022] Open
Abstract
Chromosome fusions threaten genome integrity and promote cancer by engaging catastrophic mutational processes, namely chromosome breakage-fusion-bridge cycles and chromothripsis. Chromosome fusions are frequent in cells incurring telomere dysfunctions or those exposed to DNA breakage. Their occurrence and therefore their contribution to genome instability in unchallenged cells is unknown. To address this issue, we constructed a genetic assay able to capture and quantify rare chromosome fusions in budding yeast. This chromosome fusion capture (CFC) assay relies on the controlled inactivation of one centromere to rescue unstable dicentric chromosome fusions. It is sensitive enough to quantify the basal rate of end-to-end chromosome fusions occurring in wild-type cells. These fusions depend on canonical nonhomologous end joining (NHEJ). Our results show that chromosome end protection results from a trade-off at telomeres between positive effectors (Rif2, Sir4, telomerase) and a negative effector partially antagonizing them (Rif1). The CFC assay also captures NHEJ-dependent chromosome fusions induced by ionizing radiation. It provides evidence for chromosomal rearrangements stemming from a single photon-matter interaction.
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Affiliation(s)
- Sabrina Pobiega
- Université de Paris and Université Paris-Saclay, Inserm, CEA IBFJ/iRCM, UMR Stabilité Génétique Cellules Souches et Radiations, 92265 Fontenay-au-Roses, France
| | | | - Stéphane Marcand
- To whom correspondence should be addressed. Tel: +33 1 46 54 82 33;
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21
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Rachakonda S, Hoheisel JD, Kumar R. Occurrence, functionality and abundance of the TERT promoter mutations. Int J Cancer 2021; 149:1852-1862. [PMID: 34313327 DOI: 10.1002/ijc.33750] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 06/14/2021] [Accepted: 07/16/2021] [Indexed: 12/18/2022]
Abstract
Telomere shortening at chromosomal ends due to the constraints of the DNA replication process acts as a tumor suppressor by restricting the replicative potential in primary cells. Cancers evade that limitation primarily through the reactivation of telomerase via different mechanisms. Mutations within the promoter of the telomerase reverse transcriptase (TERT) gene represent a definite mechanism for the ribonucleic enzyme regeneration predominantly in cancers that arise from tissues with low rates of self-renewal. The promoter mutations cause a moderate increase in TERT transcription and consequent telomerase upregulation to the levels sufficient to delay replicative senescence but not prevent bulk telomere shortening and genomic instability. Since the discovery, a staggering number of studies have resolved the discrete aspects, effects and clinical relevance of the TERT promoter mutations. The promoter mutations link transcription of TERT with oncogenic pathways, associate with markers of poor outcome and define patients with reduced survivals in several cancers. In this review, we discuss the occurrence and impact of the promoter mutations and highlight the mechanism of TERT activation. We further deliberate on the foundational question of the abundance of the TERT promoter mutations and a general dearth of functional mutations within noncoding sequences, as evident from pan-cancer analysis of the whole-genomes. We posit that the favorable genomic constellation within the TERT promoter may be less than a common occurrence in other noncoding functional elements. Besides, the evolutionary constraints limit the functional fraction within the human genome, hence the lack of abundant mutations outside the coding sequences.
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Affiliation(s)
| | - Jörg D Hoheisel
- Division of Functional Genome Analysis, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Rajiv Kumar
- Division of Functional Genome Analysis, German Cancer Research Center (DKFZ), Heidelberg, Germany.,Department of Molecular Biology of Cancer, Institute of Experimental Medicine of the Czech Academy of Sciences, Prague, Czech Republic
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22
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Li B. Keeping Balance Between Genetic Stability and Plasticity at the Telomere and Subtelomere of Trypanosoma brucei. Front Cell Dev Biol 2021; 9:699639. [PMID: 34291053 PMCID: PMC8287324 DOI: 10.3389/fcell.2021.699639] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Accepted: 06/08/2021] [Indexed: 12/13/2022] Open
Abstract
Telomeres, the nucleoprotein complexes at chromosome ends, are well-known for their essential roles in genome integrity and chromosome stability. Yet, telomeres and subtelomeres are frequently less stable than chromosome internal regions. Many subtelomeric genes are important for responding to environmental cues, and subtelomeric instability can facilitate organismal adaptation to extracellular changes, which is a common theme in a number of microbial pathogens. In this review, I will focus on the delicate and important balance between stability and plasticity at telomeres and subtelomeres of a kinetoplastid parasite, Trypanosoma brucei, which causes human African trypanosomiasis and undergoes antigenic variation to evade the host immune response. I will summarize the current understanding about T. brucei telomere protein complex, the telomeric transcript, and telomeric R-loops, focusing on their roles in maintaining telomere and subtelomere stability and integrity. The similarities and differences in functions and underlying mechanisms of T. brucei telomere factors will be compared with those in human and yeast cells.
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Affiliation(s)
- Bibo Li
- Center for Gene Regulation in Health and Disease, Department of Biological, Geological, and Environmental Sciences, College of Sciences and Health Professions, Cleveland State University, Cleveland, OH, United States.,Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH, United States.,Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States.,Center for RNA Science and Therapeutics, Case Western Reserve University, Cleveland, OH, United States
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23
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Cararo-Lopes E, Dias MH, da Silva MS, Zeidler JD, Vessoni AT, Reis MS, Boccardo E, Armelin HA. Autophagy buffers Ras-induced genotoxic stress enabling malignant transformation in keratinocytes primed by human papillomavirus. Cell Death Dis 2021; 12:194. [PMID: 33602932 PMCID: PMC7892846 DOI: 10.1038/s41419-021-03476-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 01/22/2021] [Accepted: 01/26/2021] [Indexed: 01/31/2023]
Abstract
Malignant transformation involves an orchestrated rearrangement of cell cycle regulation mechanisms that must balance autonomic mitogenic impulses and deleterious oncogenic stress. Human papillomavirus (HPV) infection is highly prevalent in populations around the globe, whereas the incidence of cervical cancer is 0.15%. Since HPV infection primes cervical keratinocytes to undergo malignant transformation, we can assume that the balance between transforming mitogenic signals and oncogenic stress is rarely attained. We showed that highly transforming mitogenic signals triggered by HRasG12V activity in E6E7-HPV-keratinocytes generate strong replication and oxidative stresses. These stresses are counteracted by autophagy induction that buffers the rapid increase of ROS that is the main cause of genotoxic stress promoted by the oncoprotein. As a result, autophagy creates a narrow window of opportunity for malignant keratinocytes to emerge. This work shows that autophagy is crucial to allow the transition of E6E7 keratinocytes from an immortalized to a malignant state caused by HRasG12V.
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Affiliation(s)
- Eduardo Cararo-Lopes
- Center of Toxins, Immune-response and Cell Signaling, Instituto Butantan, São Paulo, SP, 05503-900, Brazil.
- Department of Biochemistry, Instituto de Química, Universidade de São Paulo, São Paulo, SP, 05508-000, Brazil.
- Rutgers Cancer Institute of New Jersey, New Brunswick, NJ, 08901, USA.
| | - Matheus H Dias
- Center of Toxins, Immune-response and Cell Signaling, Instituto Butantan, São Paulo, SP, 05503-900, Brazil
| | - Marcelo S da Silva
- Center of Toxins, Immune-response and Cell Signaling, Instituto Butantan, São Paulo, SP, 05503-900, Brazil
- Department of Chemical and Biological Sciences, Instituto de Biociência, Universidade do Estado de São Paulo, Botucatu, SP, 18618-689, Brazil
| | - Julianna D Zeidler
- Center of Toxins, Immune-response and Cell Signaling, Instituto Butantan, São Paulo, SP, 05503-900, Brazil
- Kogod Aging Center, Department of Anesthesiology and Perioperative Medicine, Mayo Clinic College of Medicine, Rochester, MN, 55905, USA
| | - Alexandre T Vessoni
- Department of Medicine, Washington University in St. Louis, St. Louis, MO, 63110, USA
| | - Marcelo S Reis
- Center of Toxins, Immune-response and Cell Signaling, Instituto Butantan, São Paulo, SP, 05503-900, Brazil
| | - Enrique Boccardo
- Department of Microbiology, Instituto de Biociências, Universidade de São Paulo, São Paulo, SP, 05508-900, Brazil
| | - Hugo A Armelin
- Center of Toxins, Immune-response and Cell Signaling, Instituto Butantan, São Paulo, SP, 05503-900, Brazil.
- Department of Biochemistry, Instituto de Química, Universidade de São Paulo, São Paulo, SP, 05508-000, Brazil.
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24
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Pellestor F, Gaillard JB, Schneider A, Puechberty J, Gatinois V. Chromoanagenesis, the mechanisms of a genomic chaos. Semin Cell Dev Biol 2021; 123:90-99. [PMID: 33608210 DOI: 10.1016/j.semcdb.2021.01.004] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Accepted: 01/22/2021] [Indexed: 02/07/2023]
Abstract
Designated under the name of chromoanagenesis, the phenomena of chromothripsis, chromanasynthesis and chromoplexy constitute new types of complex rearrangements, including many genomic alterations localized on a few chromosomal regions, and whose discovery over the last decade has changed our perception about the formation of chromosomal abnormalities and their etiology. Although exhibiting specific features, these new catastrophic mechanisms generally occur within a single cell cycle and their emergence is closely linked to genomic instability. Various non-exclusive exogenous or cellular mechanisms capable of generating chromoanagenesis have been evoked. However, recent experimental data shed light on 2 major processes, which following a defect in the mitotic segregation of chromosomes, can generate a cascade of cellular events leading to chromoanagenesis. These mechanisms are the formation of micronuclei integrating isolated chromosomal material, and the occurrence of chromatin bridges around chromosomal material resulting from telomeric fusions. In both cases, the cellular and molecular mechanisms of fragmentation, repair and transmission of damaged chromosomal material are consistent with the features of chromoanagenesis-related complex chromosomal rearrangements. In this review, we introduce each type of chromoanagenesis, and describe the experimental models that have allowed to validate the existence of chromoanagenesis events and to better understand their cellular mechanisms of formation and transmission, as well as their impact on the stability and the plasticity of the genome.
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Affiliation(s)
- F Pellestor
- Unit of Chromosomal Genetics and Research Plateform Chromostem, Department of Medical Genetics, Arnaud de Villeneuve Hospital, Montpellier CHU, 371 avenue du Doyen Gaston Giraud, Montpellier Cedex 5 34295, France; INSERM 1183 Unit "Genome and Stem Cell Plasticity in Development and Aging" Institute of Regenerative Medecine and Biotherapies, St Eloi Hospital, Montpellier, France.
| | - J B Gaillard
- Unit of Chromosomal Genetics and Research Plateform Chromostem, Department of Medical Genetics, Arnaud de Villeneuve Hospital, Montpellier CHU, 371 avenue du Doyen Gaston Giraud, Montpellier Cedex 5 34295, France
| | - A Schneider
- Unit of Chromosomal Genetics and Research Plateform Chromostem, Department of Medical Genetics, Arnaud de Villeneuve Hospital, Montpellier CHU, 371 avenue du Doyen Gaston Giraud, Montpellier Cedex 5 34295, France
| | - J Puechberty
- Unit of Chromosomal Genetics and Research Plateform Chromostem, Department of Medical Genetics, Arnaud de Villeneuve Hospital, Montpellier CHU, 371 avenue du Doyen Gaston Giraud, Montpellier Cedex 5 34295, France
| | - V Gatinois
- Unit of Chromosomal Genetics and Research Plateform Chromostem, Department of Medical Genetics, Arnaud de Villeneuve Hospital, Montpellier CHU, 371 avenue du Doyen Gaston Giraud, Montpellier Cedex 5 34295, France; INSERM 1183 Unit "Genome and Stem Cell Plasticity in Development and Aging" Institute of Regenerative Medecine and Biotherapies, St Eloi Hospital, Montpellier, France
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25
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Using telomeric chromosomal aberrations to evaluate clastogen-induced genomic instability in mammalian cells. Chromosome Res 2020; 28:259-276. [DOI: 10.1007/s10577-020-09641-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 09/06/2020] [Accepted: 09/06/2020] [Indexed: 12/13/2022]
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