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Tan X, Kong D, Tao Z, Cheng F, Zhang B, Wang Z, Mei Q, Chen C, Wu K. Simultaneous inhibition of FAK and ROS1 synergistically repressed triple-negative breast cancer by upregulating p53 signalling. Biomark Res 2024; 12:13. [PMID: 38273343 PMCID: PMC10809663 DOI: 10.1186/s40364-024-00558-0] [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: 11/14/2023] [Accepted: 01/02/2024] [Indexed: 01/27/2024] Open
Abstract
BACKGROUND Triple-negative breast cancer (TNBC) is an aggressive breast cancer subtype lacking effective targeted therapies, necessitating innovative treatment approaches. While targeting ROS proto-oncogene 1 (ROS1) with crizotinib has shown promise, resistance remains a limitation. Recent evidence links focal adhesion kinase (FAK) to drug resistance, prompting our study to assess the combined impact of FAK inhibitor IN10018 and crizotinib in TNBC and elucidate the underlying mechanisms. METHODS We employed the Timer database to analyze FAK and ROS1 mRNA levels in TNBC and adjacent normal tissues. Furthermore, we investigated the correlation between FAK, ROS1, and TNBC clinical prognosis using the GSE database. We conducted various in vitro assays, including cell viability, colony formation, flow cytometry, EdU assays, and western blotting. Additionally, TNBC xenograft and human TNBC organoid models were established to assess the combined therapy's efficacy. To comprehensively understand the synergistic anti-tumor mechanisms, we utilized multiple techniques, such as RNA sequencing, immunofluorescence, cell flow cytometry, C11-BODIPY staining, MDA assay, and GSH assay. RESULTS The Timer database revealed higher levels of FAK and ROS1 in TNBC tissues compared to normal tissues. Analysis of GEO databases indicated that patients with high FAK and ROS1 expression had the poorest prognosis. Western blotting confirmed increased p-FAK expression in crizotinib-resistant TNBC cells. In vitro experiments showed that the combination therapy down-regulated cyclin B1, p-Cdc2, and Bcl2 while up-regulating BAX, cleaved-Caspase-3, cleaved-Caspase-9, and cleaved PARP. In TNBC xenograft models, the tumor volume in the combination therapy group was 73% smaller compared to the control group (p < 0.0001). Additionally, the combination therapy resulted in a 70% reduction in cell viability in human TNBC organoid models (p < 0.0001). RNA sequencing analysis of TNBC cells and xenograft tumor tissues highlighted enrichment in oxidative stress, glutathione metabolism, and p53 pathways. The combined group displayed a fivefold rise in the reactive oxygen species level, a 69% decrease in the GSH/GSSG ratio, and a sixfold increase in the lipid peroxidation in comparison to the control group. Western blotting demonstrated p53 upregulation and SCL7A11 and GPX4 downregulation in the combination group. The addition of a p53 inhibitor reversed these effects. CONCLUSION Our study demonstrates that the combination of IN10018 and crizotinib shows synergistic antitumor effects in TNBC. Mechanistically, this combination inhibits cell proliferation, enhances apoptosis, and induces ferroptosis, which is associated with increased p53 levels.
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Affiliation(s)
- Ximin Tan
- Department of Oncology, Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Deguang Kong
- Department of Breast and Thyroid Surgery, Renmin Hospital of Wuhan University, 238 Ziyang Road, Wuhan, 430060, China
| | - Zhuoli Tao
- Department of Breast and Thyroid Surgery, Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Fangling Cheng
- Hepatic Surgery Center, Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | | | - Zaiqi Wang
- InxMed (Shanghai) Co. Ltd, Shanghai, China
| | - Qi Mei
- Cancer Center, Shanxi Bethune Hospital, Shanxi Academy of Medical Science, Tongji Shanxi Hospital, Third Hospital of Shanxi Medical University, Taiyuan, 030032, China.
- Cancer Center, Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
| | - Chuang Chen
- Department of Breast and Thyroid Surgery, Renmin Hospital of Wuhan University, 238 Ziyang Road, Wuhan, 430060, China.
| | - Kongming Wu
- Cancer Center, Shanxi Bethune Hospital, Shanxi Academy of Medical Science, Tongji Shanxi Hospital, Third Hospital of Shanxi Medical University, Taiyuan, 030032, China.
- Cancer Center, Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
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2
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He HL, Lai HY, Chan TC, Hsing CH, Huang SK, Hsieh KL, Chen TJ, Li WS, Kuo YH, Shiue YL, Li CF. Low expression of ZSCAN4 predicts unfavorable outcome in urothelial carcinoma of upper urinary tract and urinary bladder. World J Surg Oncol 2023; 21:62. [PMID: 36841776 PMCID: PMC9960215 DOI: 10.1186/s12957-023-02948-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Accepted: 02/14/2023] [Indexed: 02/27/2023] Open
Abstract
BACKGROUND With the advance in genome-wide analyses, genetic alternations have been found to play an important role in carcinogenesis and aggressiveness of UC. Through bioinformatic analysis of gene expression profiles of urinary bladder urothelial carcinoma (UBUC) from publicly available GEO dataset (GSE31684), Zinc finger and SCAN domain containing 4 (ZSCAN4) was identified as a significant downregulated gene in muscle-invasive bladder cancer when compared with non-muscle-invasive bladder cancer. METHODS The expression of ZSCAN4 was evaluated by immunohistochemistry in 340 upper urinary tract urothelial carcinomas (UTUCs) and 295 UBUCs. The expression profiles of ZSCAN4 and potential signaling pathways were analyzed bioinformatically. RESULTS In UTUC, low expression of ZSCAN4 was significantly associated with advanced primary pT stage (P = 0.011), increased nodal metastasis (P = 0.002) and increased vascular invasion (P = 0.019). In UBUC, low expression of ZSCAN4 was significantly correlated with advanced primary pT stage (P < 0.001), increased nodal metastasis (P = 0.001), high histological grade (P = 0.003) and increased vascular invasion (P = 0.003). In survival analysis, low expression of ZSCAN4 acted as an independent negative prognostic factor for disease-specific survival and metastasis-free survival both in UTUC and UBUC. Gene ontology analysis showed that ZSCAN4 mRNA and its co-downregulated genes are associated with the mitotic cell cycle. CONCLUSIONS Low expression of ZSCAN4 predicted worse outcome in urothelial carcinoma and might have potential regulatory role in cell mitosis.
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Affiliation(s)
- Hong-Lin He
- grid.411447.30000 0004 0637 1806Department of Pathology, E-DA Cancer Hospital, I-Shou University, Kaohsiung, Taiwan
| | - Hong-Yue Lai
- grid.413876.f0000 0004 0572 9255Department of Medical Research, Chi Mei Medical Center, Tainan, Taiwan
| | - Ti-Chun Chan
- grid.413876.f0000 0004 0572 9255Department of Medical Research, Chi Mei Medical Center, Tainan, Taiwan ,grid.59784.370000000406229172National Institute of Cancer Research, National Health Research Institutes, Tainan, Taiwan
| | - Chung-Hsi Hsing
- grid.413876.f0000 0004 0572 9255Department of Medical Research, Chi Mei Medical Center, Tainan, Taiwan ,grid.413876.f0000 0004 0572 9255Department of Anesthesiology, Chi Mei Medical Center, Tainan, Taiwan
| | - Steven K. Huang
- grid.413876.f0000 0004 0572 9255Division of Urology, Department of Surgery, Chi Mei Medical Center, Tainan, Taiwan ,grid.411315.30000 0004 0634 2255Department of Biotechnology, Chia Nan University of Pharmacy and Science, Tainan, Taiwan
| | - Kun-Lin Hsieh
- grid.413876.f0000 0004 0572 9255Division of Urology, Department of Surgery, Chi Mei Medical Center, Tainan, Taiwan
| | - Tzu-Ju Chen
- grid.413876.f0000 0004 0572 9255Department of Clinical Pathology, Chi Mei Medical Center, Tainan, Taiwan ,grid.411636.70000 0004 0634 2167Department of Medical Technology, Chung Hwa University of Medical Technology, Tainan, Taiwan
| | - Wan-Shan Li
- grid.411636.70000 0004 0634 2167Department of Medical Technology, Chung Hwa University of Medical Technology, Tainan, Taiwan ,grid.413876.f0000 0004 0572 9255Department of Pathology, Chi Mei Medical Center, Tainan, Taiwan
| | - Yu-Hsuan Kuo
- grid.413876.f0000 0004 0572 9255Division of Hematology and Oncology, Department of Internal Medicine, Chi-Mei Medical Center, Tainan, Taiwan ,College of Pharmacy and Science, Chia Nan University, Tainan, Taiwan
| | - Yow-Ling Shiue
- Institute of Precision Medicine, National Sun Yat-Sen University, Kaohsiung, Taiwan.
| | - Chien-Feng Li
- Department of Medical Research, Chi Mei Medical Center, Tainan, Taiwan. .,National Institute of Cancer Research, National Health Research Institutes, Tainan, Taiwan. .,Institute of Precision Medicine, National Sun Yat-Sen University, Kaohsiung, Taiwan.
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3
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Li L, Du W, Wang H, Zhao Y, Huang Z, Peng Y, Zeng S, Zhang G. Small-molecule MX-C2/3 suppresses non-small cell lung cancer progression via p53 activation. Chem Biol Interact 2022; 366:110142. [PMID: 36058261 DOI: 10.1016/j.cbi.2022.110142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Revised: 08/22/2022] [Accepted: 08/28/2022] [Indexed: 11/30/2022]
Abstract
p53 inactivation is a common feature in non-small cell lung cancer (NSCLC) resulting in NSCLC malignant transformation. Targeting serine 392 phosphorylation to restore p53 anticancer activity has proven to be an effective therapeutic strategy against NSCLC. A synthetic p53 activator, NA-17, has been developed that shows promise in preclinical models of NSCLC. However, NA-17 exhibits limited therapeutic efficacy in oncogene-driven tumors as well as relatively high toxicity to normal cells. It is possible that high efficiency and low toxicity p53 activators can be obtained by optimizing the leading molecule. Here, we performed high-throughput screening of compounds optimized based on NA-17 to identify new p53 activators. Two promising candidates named MX-C2 and MX-C3 were identified, both exhibited considerable therapeutic efficacy in oncogene-driven tumor models. Similar to NA-17, MX-C2/3 induced p53 activation via phosphorylating serine-392 without DNA damage. Both compounds showed broad antitumor activity in NSCLC cells and limited toxicity in normal cell lines. Moreover, MX-C2/3 suppressed tumor progression by arresting the cell cycle at G2/M phase, exhibiting a different mechanism of cell cycle arrest than NA-17. In addition, MX-C2/3 promoted the enrichment of p-p53 (s392) in mitochondria, leading to the conformational activation of Bak for cell apoptosis, which is consistent with NA-17. Finally, we demonstrated that MX-C2 significantly inhibited tumor growth without obvious systemic toxicity in oncogene-driven HCC-827 xenograft models. Collectively, we report two p53 activators with high-efficiency and low-toxicity that target p53 serine 392 phosphorylation for anticancer translational investigation.
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Affiliation(s)
- Liangping Li
- State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources/Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources (Ministry of Education of China), Collaborative Innovation Center for Guangxi Ethnic Medicine, School of Chemistry and Pharmaceutical Sciences, Guangxi Normal University, Guilin, 541004, China
| | - Wenqing Du
- State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources/Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources (Ministry of Education of China), Collaborative Innovation Center for Guangxi Ethnic Medicine, School of Chemistry and Pharmaceutical Sciences, Guangxi Normal University, Guilin, 541004, China
| | - Hui Wang
- State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources/Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources (Ministry of Education of China), Collaborative Innovation Center for Guangxi Ethnic Medicine, School of Chemistry and Pharmaceutical Sciences, Guangxi Normal University, Guilin, 541004, China
| | - Yufei Zhao
- State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources/Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources (Ministry of Education of China), Collaborative Innovation Center for Guangxi Ethnic Medicine, School of Chemistry and Pharmaceutical Sciences, Guangxi Normal University, Guilin, 541004, China
| | - Zetian Huang
- State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources/Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources (Ministry of Education of China), Collaborative Innovation Center for Guangxi Ethnic Medicine, School of Chemistry and Pharmaceutical Sciences, Guangxi Normal University, Guilin, 541004, China
| | - Yan Peng
- State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources/Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources (Ministry of Education of China), Collaborative Innovation Center for Guangxi Ethnic Medicine, School of Chemistry and Pharmaceutical Sciences, Guangxi Normal University, Guilin, 541004, China
| | - Shulan Zeng
- State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources/Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources (Ministry of Education of China), Collaborative Innovation Center for Guangxi Ethnic Medicine, School of Chemistry and Pharmaceutical Sciences, Guangxi Normal University, Guilin, 541004, China.
| | - Guohai Zhang
- State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources/Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources (Ministry of Education of China), Collaborative Innovation Center for Guangxi Ethnic Medicine, School of Chemistry and Pharmaceutical Sciences, Guangxi Normal University, Guilin, 541004, China.
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4
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p53 at the crossroad of DNA replication and ribosome biogenesis stress pathways. Cell Death Differ 2022; 29:972-982. [PMID: 35444234 PMCID: PMC9090812 DOI: 10.1038/s41418-022-00999-w] [Citation(s) in RCA: 53] [Impact Index Per Article: 26.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Revised: 03/28/2022] [Accepted: 03/30/2022] [Indexed: 01/05/2023] Open
Abstract
Despite several decades of intense research focused on understanding function(s) and disease-associated malfunction of p53, there is no sign of any “mid-life crisis” in this rapidly advancing area of biomedicine. Firmly established as the hub of cellular stress responses and tumor suppressor targeted in most malignancies, p53’s many talents continue to surprise us, providing not only fresh insights into cell and organismal biology, but also new avenues to cancer treatment. Among the most fruitful lines of p53 research in recent years have been the discoveries revealing the multifaceted roles of p53-centered pathways in the fundamental processes of DNA replication and ribosome biogenesis (RiBi), along with cellular responses to replication and RiBi stresses, two intertwined areas of cell (patho)physiology that we discuss in this review. Here, we first provide concise introductory notes on the canonical roles of p53, the key interacting proteins, downstream targets and post-translational modifications involved in p53 regulation. We then highlight the emerging involvement of p53 as a key component of the DNA replication Fork Speed Regulatory Network and the mechanistic links of p53 with cellular checkpoint responses to replication stress (RS), the driving force of cancer-associated genomic instability. Next, the tantalizing, yet still rather foggy functional crosstalk between replication and RiBi (nucleolar) stresses is considered, followed by the more defined involvement of p53-mediated monitoring of the multistep process of RiBi, including the latest updates on the RPL5/RPL11/5 S rRNA-MDM2-p53-mediated Impaired Ribosome Biogenesis Checkpoint (IRBC) pathway and its involvement in tumorigenesis. The diverse defects of RiBi and IRBC that predispose and/or contribute to severe human pathologies including developmental syndromes and cancer are then outlined, along with examples of promising small-molecule-based strategies to therapeutically target the RS- and particularly RiBi- stress-tolerance mechanisms to which cancer cells are addicted due to their aberrant DNA replication, repair, and proteo-synthesis demands. ![]()
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5
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Li X, Li X, Xie C, Cai S, Li M, Jin H, Wu S, Cui J, Liu H, Zhao Y. cGAS guards against chromosome end-to-end fusions during mitosis and facilitates replicative senescence. Protein Cell 2021; 13:47-64. [PMID: 34676498 PMCID: PMC8776970 DOI: 10.1007/s13238-021-00879-y] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Accepted: 09/06/2021] [Indexed: 01/07/2023] Open
Abstract
As a sensor of cytosolic DNA, the role of cyclic GMP-AMP synthase (cGAS) in innate immune response is well established, yet how its functions in different biological conditions remain to be elucidated. Here, we identify cGAS as an essential regulator in inhibiting mitotic DNA double-strand break (DSB) repair and protecting short telomeres from end-to-end fusion independent of the canonical cGAS-STING pathway. cGAS associates with telomeric/subtelomeric DNA during mitosis when TRF1/TRF2/POT1 are deficient on telomeres. Depletion of cGAS leads to mitotic chromosome end-to-end fusions predominantly occurring between short telomeres. Mechanistically, cGAS interacts with CDK1 and positions them to chromosome ends. Thus, CDK1 inhibits mitotic non-homologous end joining (NHEJ) by blocking the recruitment of RNF8. cGAS-deficient human primary cells are defective in entering replicative senescence and display chromosome end-to-end fusions, genome instability and prolonged growth arrest. Altogether, cGAS safeguards genome stability by controlling mitotic DSB repair to inhibit mitotic chromosome end-to-end fusions, thus facilitating replicative senescence.
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Affiliation(s)
- Xiaocui Li
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510006, China
| | - Xiaojuan Li
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510006, China
| | - Chen Xie
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510006, China
| | - Sihui Cai
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510006, China
| | - Mengqiu Li
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510006, China
| | - Heping Jin
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510006, China
| | - Shu Wu
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510006, China
| | - Jun Cui
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510006, China
| | - Haiying Liu
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510006, China. .,Department of Biochemistry, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510006, China.
| | - Yong Zhao
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510006, China.,State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, 510006, China
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6
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Engin AB, Engin A. The Connection Between Cell Fate and Telomere. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1275:71-100. [PMID: 33539012 DOI: 10.1007/978-3-030-49844-3_3] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Abolition of telomerase activity results in telomere shortening, a process that eventually destabilizes the ends of chromosomes, leading to genomic instability and cell growth arrest or death. Telomere shortening leads to the attainment of the "Hayflick limit", and the transition of cells to state of senescence. If senescence is bypassed, cells undergo crisis through loss of checkpoints. This process causes massive cell death concomitant with further telomere shortening and spontaneous telomere fusions. In functional telomere of mammalian cells, DNA contains double-stranded tandem repeats of TTAGGG. The Shelterin complex, which is composed of six different proteins, is required for the regulation of telomere length and stability in cells. Telomere protection by telomeric repeat binding protein 2 (TRF2) is dependent on DNA damage response (DDR) inhibition via formation of T-loop structures. Many protein kinases contribute to the DDR activated cell cycle checkpoint pathways, and prevent DNA replication until damaged DNA is repaired. Thereby, the connection between cell fate and telomere length-associated telomerase activity is regulated by multiple protein kinase activities. Contrarily, inactivation of DNA damage checkpoint protein kinases in senescent cells can restore cell-cycle progression into S phase. Therefore, telomere-initiated senescence is a DNA damage checkpoint response that is activated with a direct contribution from dysfunctional telomeres. In this review, in addition to the above mentioned, the choice of main repair pathways, which comprise non-homologous end joining and homologous recombination in telomere uncapping telomere dysfunctions, are discussed.
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Affiliation(s)
- Ayse Basak Engin
- Department of Toxicology, Faculty of Pharmacy, Gazi University, Ankara, Turkey.
| | - Atilla Engin
- Department of General Surgery, Faculty of Medicine, Gazi University, Ankara, Turkey
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Razgonova MP, Zakharenko AM, Golokhvast KS, Thanasoula M, Sarandi E, Nikolouzakis K, Fragkiadaki P, Tsoukalas D, Spandidos DA, Tsatsakis A. Telomerase and telomeres in aging theory and chronographic aging theory (Review). Mol Med Rep 2020; 22:1679-1694. [PMID: 32705188 PMCID: PMC7411297 DOI: 10.3892/mmr.2020.11274] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Accepted: 06/24/2020] [Indexed: 01/03/2023] Open
Abstract
The current review focuses on the connection of telomerase and telomeres with aging. In this review, we describe the changes in telomerase and telomere length (TEL) during development, their role in carcinogenesis processes, and the consequences of reduced telomerase activity. More specifically, the connection of TEL in peripheral blood cells with the development of aging‑associated diseases is discussed. The review provides systematic data on the role of telomerase in mitochondria, the biology of telomeres in stem cells, as well as the consequences of the forced expression of telomerase (telomerization) in human cells. Additionally, it presents the effects of chronic stress exposure on telomerase activity, the effect of TEL on fertility, and the effect of nutraceutical supplements on TEL. Finally, a comparative review of the chronographic theory of aging, presented by Olovnikov is provided based on currently available scientific research on telomere, telomerase activity, and the nature of aging by multicellular organisms.
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Affiliation(s)
- Mayya P. Razgonova
- N.I. Vavilov All-Russian Institute of Plant Genetic Resources, 190000 Saint-Petersburg, Russia
- Far Eastern Federal University, 690950 Vladivostok, Russia
| | - Alexander M. Zakharenko
- N.I. Vavilov All-Russian Institute of Plant Genetic Resources, 190000 Saint-Petersburg, Russia
- Far Eastern Federal University, 690950 Vladivostok, Russia
| | - Kirill S. Golokhvast
- N.I. Vavilov All-Russian Institute of Plant Genetic Resources, 190000 Saint-Petersburg, Russia
- Far Eastern Federal University, 690950 Vladivostok, Russia
- Pacific Geographical Institute, Far Eastern Branch of The Russian Academy of Sciences, 690041 Vladivostok, Russia
| | - Maria Thanasoula
- Metabolomic Μedicine, Health Clinics for Autoimmune and Chronic Diseases, 10674 Athens, Greece
| | - Evangelia Sarandi
- Metabolomic Μedicine, Health Clinics for Autoimmune and Chronic Diseases, 10674 Athens, Greece
| | | | - Persefoni Fragkiadaki
- Laboratory of Toxicology, Medical School, University of Crete, 71003 Heraklion, Greece
- Spin-Off Toxplus S.A., 71601 Heraklion, Greece
| | - Dimitris Tsoukalas
- Metabolomic Μedicine, Health Clinics for Autoimmune and Chronic Diseases, 10674 Athens, Greece
| | - Demetrios A. Spandidos
- Laboratory of Clinical Virology, School of Medicine, University of Crete, Heraklion 71003, Greece
| | - Aristidis Tsatsakis
- Laboratory of Toxicology, Medical School, University of Crete, 71003 Heraklion, Greece
- Spin-Off Toxplus S.A., 71601 Heraklion, Greece
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8
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Fragkiadaki P, Nikitovic D, Kalliantasi K, Sarandi E, Thanasoula M, Stivaktakis PD, Nepka C, Spandidos DA, Tosounidis T, Tsatsakis A. Telomere length and telomerase activity in osteoporosis and osteoarthritis. Exp Ther Med 2019; 19:1626-1632. [PMID: 32104213 PMCID: PMC7027092 DOI: 10.3892/etm.2019.8370] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Accepted: 12/23/2019] [Indexed: 12/11/2022] Open
Abstract
Osteoarthritis (OA) and osteoporosis (OP) are associated skeletal pathologies and have as a distinct feature the abnormal reconstruction of the subchondral bone. OA and OP have been characterized as age-related diseases and have been associated with telomere shortening and altered telomerase activity (TA). This review discusses the role of telomeres and telomerase in OA and OP pathologies and focuses on the usability of telomere length (TL) and the rate of telomere shortening as potential disease biomarkers. A number of studies have demonstrated that telomere shortening may contribute to OA and OP as an epigenetic factor. Therefore, it has been claimed that the measurement of TL of chondrocytes and/or peripheral blood cells may be an appropriate marker for the evaluation of the progression of these diseases. However, there is a need to be perform further studies with larger cohorts, with the aim of obtaining objective results and a better understanding of the association between TL, inflammation and aging, in order to provide further insight into the pathophysiology of degenerative joint diseases.
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Affiliation(s)
- Persefoni Fragkiadaki
- Laboratory of Toxicology, Medical School, University of Crete, 71003 Heraklion, Greece.,Spin-Off Toxplus S.A., 71601 Heraklion, Greece
| | - Dragana Nikitovic
- Laboratory of Anatomy-Histology-Embryology, Medical School, University of Crete, 71003 Heraklion, Greece
| | - Katerina Kalliantasi
- Laboratory of Toxicology, Medical School, University of Crete, 71003 Heraklion, Greece
| | - Evangelia Sarandi
- Laboratory of Toxicology, Medical School, University of Crete, 71003 Heraklion, Greece.,Metabolomic Medicine, Health Clinic for Autoimmune and Chronic Diseases, 10674 Athens, Greece
| | - Maria Thanasoula
- Metabolomic Medicine, Health Clinic for Autoimmune and Chronic Diseases, 10674 Athens, Greece
| | - Polychronis D Stivaktakis
- Laboratory of Toxicology, Medical School, University of Crete, 71003 Heraklion, Greece.,Spin-Off Toxplus S.A., 71601 Heraklion, Greece
| | - Charitini Nepka
- Department of Cytopathology, University Hospital of Larissa, 41110 Larissa, Greece
| | - Demetrios A Spandidos
- Laboratory of Clinical Virology, School of Medicine, University of Crete, 71003 Heraklion, Greece
| | - Theodoros Tosounidis
- Department of Orthopedics, School of Medicine, University of Crete, 71003 Heraklion, Greece
| | - Aristidis Tsatsakis
- Laboratory of Toxicology, Medical School, University of Crete, 71003 Heraklion, Greece.,Spin-Off Toxplus S.A., 71601 Heraklion, Greece
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9
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Tsoukalas D, Fragkiadaki P, Docea AO, Alegakis AK, Sarandi E, Thanasoula M, Spandidos DA, Tsatsakis A, Razgonova MP, Calina D. Discovery of potent telomerase activators: Unfolding new therapeutic and anti-aging perspectives. Mol Med Rep 2019; 20:3701-3708. [PMID: 31485647 PMCID: PMC6755196 DOI: 10.3892/mmr.2019.10614] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Accepted: 08/09/2019] [Indexed: 12/14/2022] Open
Abstract
Telomere length, a marker of cellular aging, decreases with age and it has been associated with aging‑related diseases. Environmental factors, including diet and lifestyle factors, affect the rate of telomere shortening which can be reversed by telomerase. Telomerase activation by natural molecules has been suggested to be an anti‑aging modulator that can play a role in the treatment of aging‑related diseases. This study aimed to investigate the effect of natural compounds on telomerase activity in human peripheral blood mononuclear cells (PBMCs). The tested compounds included Centella asiatica extract formulation (08AGTLF), Astragalus extract formulation (Nutrient 4), TA‑65 (containing Astragalus membranaceus extract), oleanolic acid (OA), maslinic acid (MA), and 3 multi‑nutrient formulas (Nutrients 1, 2 and 3) at various concentrations. The mean absorbance values of telomerase activity measured following treatment with some of the above‑mentioned formulations were statistically significantly higher compared to those of the untreated cells. In particular, in order of importance with respect to telomerase activation from highest to lowest, 08AGTLF, OA, Nutrient 4, TA‑65, MA, Nutrient 3 and Nutrient 2, triggered statistically significant increase in telomerase activity compared to the untreated cells. 08AGTLF reached the highest levels of telomerase activity reported to date, at least to our knowledge, increasing telomerase activity by 8.8 folds compared to untreated cells, while Nutrient 4 and OA were also potent activators (4.3‑fold and 5.9‑fold increase, respectively). On the whole, this study indicates that the synergistic effect of nutrients and natural compounds can activate telomerase and produce more potent formulations. Human clinical studies using these formulations are required to evaluate their mode of action. This would reveal the health benefits of telomerase activation through natural molecules and would shed new light onto the treatment of aging‑related diseases.
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Affiliation(s)
- Dimitris Tsoukalas
- Metabolomic Μedicine, Health Clinics for Autoimmune and Chronic Diseases, 10674 Athens, Greece
| | - Persefoni Fragkiadaki
- Laboratory of Toxicology, Medical School, University of Crete, 71003 Heraklion, Greece
| | - Anca Oana Docea
- Department of Toxicology, University of Medicine and Pharmacy, Faculty of Pharmacy, 200349 Craiova, Romania
| | - Athanasios K Alegakis
- Laboratory of Toxicology, Medical School, University of Crete, 71003 Heraklion, Greece
| | - Evangelia Sarandi
- Metabolomic Μedicine, Health Clinics for Autoimmune and Chronic Diseases, 10674 Athens, Greece
| | - Maria Thanasoula
- Metabolomic Μedicine, Health Clinics for Autoimmune and Chronic Diseases, 10674 Athens, Greece
| | - Demetrios A Spandidos
- Laboratory of Clinical Virology, School of Medicine, University of Crete, 71003 Heraklion, Greece
| | - Aristidis Tsatsakis
- Laboratory of Toxicology, Medical School, University of Crete, 71003 Heraklion, Greece
| | | | - Daniela Calina
- Department of Clinical Pharmacy, University of Medicine and Pharmacy, Faculty of Pharmacy, 200349 Craiova, Romania
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10
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Complex structural rearrangements are present in high-grade dysplastic Barrett's oesophagus samples. BMC Med Genomics 2019; 12:31. [PMID: 30717762 PMCID: PMC6360790 DOI: 10.1186/s12920-019-0476-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Accepted: 01/14/2019] [Indexed: 12/20/2022] Open
Abstract
Background Oesophageal adenocarcinoma (EAC) incidence is increasing and has a poor survival rate. Barrett’s oesophagus (BE) is a precursor condition that is associated with EAC and often occurs in conjunction with chronic gastro-oesophageal reflux, however many individuals diagnosed with BE never progress to cancer. An understanding of the genomic features of BE and EAC may help with the early identification of at-risk individuals. Methods In this study, we assessed the genomic features of 16 BE samples using whole-genome sequencing. These included non-dysplastic samples collected at two time-points from two BE patients who had not progressed to EAC over several years. Seven other non-dysplastic samples and five dysplastic BE samples with high-grade dysplasia were also examined. We compared the genome profiles of these 16 BE samples with 22 EAC samples. Results We observed that samples from the two non-progressor individuals had low numbers of somatic single nucleotide variants, indels and structural variation events compared to dysplastic and the remaining non-dysplastic BE. EAC had the highest level of somatic genomic variations. Mutational signature 17, which is common in EAC, was also present in non-dysplastic and dysplastic BE, but was not present in the non-progressors. Many dysplastic samples had mutations in genes previously reported in EAC, whereas only mutations in CDKN2A or in the fragile site genes appeared common in non-dysplastic samples. Rearrangement signatures were used to identify a signature associated with localised complex events such as chromothripsis and breakage fusion-bridge that are characteristic of EACs. Two dysplastic BE samples had a high contribution of this signature and contained evidence of localised rearrangements. Two other dysplastic samples also had regions of localised structural rearrangements. There was no evidence for complex events in non-dysplastic samples. Conclusions The presence of complex localised rearrangements in dysplastic samples indicates a need for further investigations into the role such events play in the progression from BE to EAC. Electronic supplementary material The online version of this article (10.1186/s12920-019-0476-9) contains supplementary material, which is available to authorized users.
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11
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Ryu H, Nam KY, Kim JS, Hwang SG, Song JY, Ahn J. The small molecule AU14022 promotes colorectal cancer cell death via p53-mediated G2/M-phase arrest and mitochondria-mediated apoptosis. J Cell Physiol 2018; 233:4666-4676. [DOI: 10.1002/jcp.26234] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Accepted: 10/05/2017] [Indexed: 11/10/2022]
Affiliation(s)
- Hwani Ryu
- Division of Radiation Cancer Research; Korea Institute of Radiological and Medical Sciences; Seoul Korea
| | - Ky-Youb Nam
- Research Center; Pharos I&BT Co., Ltd.; Anyang Korea
| | - Jae Sung Kim
- Division of Radiation Cancer Research; Korea Institute of Radiological and Medical Sciences; Seoul Korea
| | - Sang-Gu Hwang
- Division of Radiation Cancer Research; Korea Institute of Radiological and Medical Sciences; Seoul Korea
| | - Jie-Young Song
- Division of Radiation Cancer Research; Korea Institute of Radiological and Medical Sciences; Seoul Korea
| | - Jiyeon Ahn
- Division of Radiation Cancer Research; Korea Institute of Radiological and Medical Sciences; Seoul Korea
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12
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Abstract
The highly complex structural genome variations chromothripsis, chromoanasynthesis, and chromoplexy are subsumed under the term chromoanagenesis, which means chromosome rebirth. Precipitated by numerous DNA double-strand breaks, they differ in number of and distances between breakpoints, associated copy number variations, order and orientation of segments, and flanking sequences at joining points. Results from patients with the autosomal dominant cancer susceptibility disorder Li-Fraumeni syndrome implicated somatic TP53 mutations in chromothripsis. TP53 participates in the G2/M phase checkpoint, halting cell cycling after premature chromosome compaction during the second half of the S phase, thus preventing chromosome shattering. By experimental TP53 ablation and micronucleus induction, one or a few isolated chromosomes underwent desynchronized replication and chromothripsis. Secondly, chromothripsis occurred after experimental induction of telomere crisis after which dicentric chromosomes sustained TREX1-mediated resolution of chromosome bridges and kataegis. Third, DNA polymerase Polθ-dependent chromothripsis has been documented. Finally, a family with chromothripsis after L1 element-dependent retrotransposition and Alu/Alu homologous recombination has been reported. Human chromosomal instability syndromes share defects in responses to DNA double-strand breaks, characteristic cell cycle perturbations, elevated rates of micronucleus formation, premature chromosome compaction, and apoptosis. They are also associated with elevated susceptibility to malignant disease, such as medulloblastomas and gliomas in ataxia-telangiectasia, leukemia and lymphoma in Bloom syndrome, and osteosarcoma and soft tissue sarcoma in Werner syndrome. The latter syndrome is characterized by a premature aging-like progressive decline of mesenchymal tissues. In all thus far studied cases, constitutional chromothripsis occurred in the male germline and male patients with defects in the double-strand break response genes ATM, MRE11, BLM, LIG4, WRN, and Ku70 show impaired fertility. Conceivably, chromothripsis may, in a stochastic rather than deterministic way, be implicated in germline structural variation, malignant disease, premature aging, genome mosaicism in somatic tissues, and male infertility.
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Affiliation(s)
- Martin Poot
- Department of Human Genetics, University of Würzburg, Würzburg, Germany.
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13
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Zhou G, Liu X, Li Y, Xu S, Ma C, Wu X, Cheng Y, Yu Z, Zhao G, Chen Y. Telomere targeting with a novel G-quadruplex-interactive ligand BRACO-19 induces T-loop disassembly and telomerase displacement in human glioblastoma cells. Oncotarget 2017; 7:14925-39. [PMID: 26908447 PMCID: PMC4924762 DOI: 10.18632/oncotarget.7483] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Accepted: 01/29/2016] [Indexed: 12/12/2022] Open
Abstract
Interference with telomerase and telomere maintenance is emerging as an attractive target for anticancer therapies. Ligand-induced stabilization of G-quadruplex formation by the telomeric DNA 3'-overhang inhibits telomerase from catalyzing telomeric DNA synthesis and from capping telomeric ends, making these ligands good candidates for chemotherapeutic purposes. BRACO-19 is one of the most effective and specific ligand for telomeric G4. It is shown here that BRACO-19 suppresses proliferation and reduces telomerase activity in human glioblastoma cells, paralleled by the displacement of telomerase from nuclear to cytoplasm. Meanwhile, BRACO-19 triggers extensive DNA damage response at telomere, which may result from uncapping and disassembly of telomeric T-loop structure, characterized by the formation of anaphase bridge and telomere fusion, as well as the release of telomere-binding protein from telomere. The resulting dysfunctional telomere ultimately provokes p53 and p21-mediated cell cycle arrest, apoptosis and senescence. Notably, normal primary astrocytes do not respond to the treatment of BRACO-19, suggesting the agent's good selectivity for cancer cells. These results reinforce the notion that G-quadruplex binding compounds can act as broad inhibitors of telomere-related processes and have potential as selective antineoplastic drugs for various tumors including malignant gliomas.
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Affiliation(s)
- Guangtong Zhou
- Department of Neurosurgery, First Hospital of Jilin University, Changchun, China
| | - Xinrui Liu
- Department of Neurosurgery, First Hospital of Jilin University, Changchun, China
| | - Yunqian Li
- Department of Neurosurgery, First Hospital of Jilin University, Changchun, China
| | - Songbai Xu
- Department of Neurosurgery, First Hospital of Jilin University, Changchun, China
| | - Chengyuan Ma
- Department of Neurosurgery, First Hospital of Jilin University, Changchun, China
| | - Xinmin Wu
- Department of Neurosurgery, First Hospital of Jilin University, Changchun, China
| | - Ye Cheng
- Department of Neurosurgery, First Hospital of Jilin University, Changchun, China
| | - Zhiyun Yu
- Department of Neurosurgery, First Hospital of Jilin University, Changchun, China
| | - Gang Zhao
- Department of Neurosurgery, First Hospital of Jilin University, Changchun, China
| | - Yong Chen
- Department of Neurosurgery, First Hospital of Jilin University, Changchun, China
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14
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Sanderson SL, Simon AK. In aged primary T cells, mitochondrial stress contributes to telomere attrition measured by a novel imaging flow cytometry assay. Aging Cell 2017; 16:1234-1243. [PMID: 28834142 PMCID: PMC5676074 DOI: 10.1111/acel.12640] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/04/2017] [Indexed: 12/14/2022] Open
Abstract
The decline of the immune system with age known as immune senescence contributes to inefficient pathogen clearance and is a key risk factor for many aged‐related diseases. However, reversing or halting immune aging requires more knowledge about the cell biology of senescence in immune cells. Telomere shortening, low autophagy and mitochondrial dysfunction have been shown to underpin cell senescence. While autophagy has been found to control mitochondrial damage, no link has been made to telomere attrition. In contrast, mitochondrial stress can contribute to telomere attrition and vice versa. Whereas this link has been investigated in fibroblasts or cell lines, it is unclear whether this link exists in primary cells such as human lymphocytes and whether autophagy contributes to it. As traditional methods for measuring telomere length are low throughput or unsuitable for the analysis of cell subtypes within a mixed population of primary cells, we have developed a novel sensitive flow‐FISH assay using the imaging flow cytometer. Using this assay, we show a correlation between age and increased mitochondrial reactive oxygen species in CD8+ T‐cell subsets, but not with autophagy. Telomere shortening within the CD8+ subset could be prevented in vitro by treatment with a ROS scavenger. Our novel assay is a sensitive assay to measure relative telomere length in primary cells and has revealed ROS as a contributing factor to the decline in telomere length.
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Affiliation(s)
- Sharon Lesley Sanderson
- Translational Immunology Laboratory NIHR BRC John Radcliffe Hospital Oxford OX3 9DU UK
- Kennedy Institute of Rheumatology University of Oxford Oxford OX3 7FY UK
| | - Anna Katharina Simon
- Translational Immunology Laboratory NIHR BRC John Radcliffe Hospital Oxford OX3 9DU UK
- Kennedy Institute of Rheumatology University of Oxford Oxford OX3 7FY UK
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15
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Alternative Lengthening of Telomeres Mediated by Mitotic DNA Synthesis Engages Break-Induced Replication Processes. Mol Cell Biol 2017; 37:MCB.00226-17. [PMID: 28760773 DOI: 10.1128/mcb.00226-17] [Citation(s) in RCA: 144] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2017] [Accepted: 07/20/2017] [Indexed: 01/05/2023] Open
Abstract
Alternative lengthening of telomeres (ALT) is a telomerase-independent telomere maintenance mechanism that occurs in a subset of cancers. By analyzing telomerase-positive cells and their human TERC knockout-derived ALT human cell lines, we show that ALT cells harbor more fragile telomeres representing telomere replication problems. ALT-associated replication defects trigger mitotic DNA synthesis (MiDAS) at telomeres in a RAD52-dependent, but RAD51-independent, manner. Telomeric MiDAS is a conservative DNA synthesis process, potentially mediated by break-induced replication, similar to type II ALT survivors in Saccharomyces cerevisiae Replication stresses induced by ectopic oncogenic expression of cyclin E, G-quadruplexes, or R-loop formation facilitate the ALT pathway and lead to telomere clustering, a hallmark of ALT cancers. The TIMELESS/TIPIN complex suppresses telomere clustering and telomeric MiDAS, whereas the SMC5/6 complex promotes them. In summary, ALT cells exhibit more telomere replication defects that result in persistent DNA damage responses at telomeres, leading to the engagement of telomeric MiDAS (spontaneous mitotic telomere synthesis) that is triggered by DNA replication stress, a potential driver of genomic duplications in cancer.
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16
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Cicconi A, Micheli E, Vernì F, Jackson A, Gradilla AC, Cipressa F, Raimondo D, Bosso G, Wakefield JG, Ciapponi L, Cenci G, Gatti M, Cacchione S, Raffa GD. The Drosophila telomere-capping protein Verrocchio binds single-stranded DNA and protects telomeres from DNA damage response. Nucleic Acids Res 2017; 45:3068-3085. [PMID: 27940556 PMCID: PMC5389638 DOI: 10.1093/nar/gkw1244] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Accepted: 11/28/2016] [Indexed: 12/17/2022] Open
Abstract
Drosophila telomeres are sequence-independent structures maintained by transposition to chromosome ends of three specialized retroelements rather than by telomerase activity. Fly telomeres are protected by the terminin complex that includes the HOAP, HipHop, Moi and Ver proteins. These are fast evolving, non-conserved proteins that localize and function exclusively at telomeres, protecting them from fusion events. We have previously suggested that terminin is the functional analogue of shelterin, the multi-protein complex that protects human telomeres. Here, we use electrophoretic mobility shift assay (EMSA) and atomic force microscopy (AFM) to show that Ver preferentially binds single-stranded DNA (ssDNA) with no sequence specificity. We also show that Moi and Ver form a complex in vivo. Although these two proteins are mutually dependent for their localization at telomeres, Moi neither binds ssDNA nor facilitates Ver binding to ssDNA. Consistent with these results, we found that Ver-depleted telomeres form RPA and γH2AX foci, like the human telomeres lacking the ssDNA-binding POT1 protein. Collectively, our findings suggest that Drosophila telomeres possess a ssDNA overhang like the other eukaryotes, and that the terminin complex is architecturally and functionally similar to shelterin.
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Affiliation(s)
- Alessandro Cicconi
- Dipartimento di Biologia e Biotecnologie 'C. Darwin', Sapienza, Università di Roma, 00185 Roma, Italy.,Istituto Pasteur Italia - Fondazione Cenci Bolognetti, 00185 Roma, Italy
| | - Emanuela Micheli
- Dipartimento di Biologia e Biotecnologie 'C. Darwin', Sapienza, Università di Roma, 00185 Roma, Italy.,Istituto Pasteur Italia - Fondazione Cenci Bolognetti, 00185 Roma, Italy
| | - Fiammetta Vernì
- Dipartimento di Biologia e Biotecnologie 'C. Darwin', Sapienza, Università di Roma, 00185 Roma, Italy
| | - Alison Jackson
- Biosciences, College of Life and Environmental Sciences, University of Exeter, Exeter EX4 4QD, UK
| | - Ana Citlali Gradilla
- Biosciences, College of Life and Environmental Sciences, University of Exeter, Exeter EX4 4QD, UK
| | - Francesca Cipressa
- Dipartimento di Biologia e Biotecnologie 'C. Darwin', Sapienza, Università di Roma, 00185 Roma, Italy.,Istituto Pasteur Italia - Fondazione Cenci Bolognetti, 00185 Roma, Italy.,Centro Fermi, Piazza del Viminale 1, 00184 Roma, Italy
| | - Domenico Raimondo
- Dipartimento di Medicina Molecolare, Sapienza, Università di Roma, 00185 Roma, Italy
| | - Giuseppe Bosso
- Dipartimento di Biologia e Biotecnologie 'C. Darwin', Sapienza, Università di Roma, 00185 Roma, Italy.,Istituto Pasteur Italia - Fondazione Cenci Bolognetti, 00185 Roma, Italy
| | - James G Wakefield
- Biosciences, College of Life and Environmental Sciences, University of Exeter, Exeter EX4 4QD, UK
| | - Laura Ciapponi
- Dipartimento di Biologia e Biotecnologie 'C. Darwin', Sapienza, Università di Roma, 00185 Roma, Italy
| | - Giovanni Cenci
- Dipartimento di Biologia e Biotecnologie 'C. Darwin', Sapienza, Università di Roma, 00185 Roma, Italy.,Istituto Pasteur Italia - Fondazione Cenci Bolognetti, 00185 Roma, Italy
| | - Maurizio Gatti
- Dipartimento di Biologia e Biotecnologie 'C. Darwin', Sapienza, Università di Roma, 00185 Roma, Italy.,Istituto di Biologia e Patologia Molecolari (IBPM) del CNR, 00185 Roma, Italy
| | - Stefano Cacchione
- Dipartimento di Biologia e Biotecnologie 'C. Darwin', Sapienza, Università di Roma, 00185 Roma, Italy.,Istituto Pasteur Italia - Fondazione Cenci Bolognetti, 00185 Roma, Italy
| | - Grazia Daniela Raffa
- Dipartimento di Biologia e Biotecnologie 'C. Darwin', Sapienza, Università di Roma, 00185 Roma, Italy.,Istituto Pasteur Italia - Fondazione Cenci Bolognetti, 00185 Roma, Italy
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17
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García-Beccaria M, Martínez P, Méndez-Pertuz M, Martínez S, Blanco-Aparicio C, Cañamero M, Mulero F, Ambrogio C, Flores JM, Megias D, Barbacid M, Pastor J, Blasco MA. Therapeutic inhibition of TRF1 impairs the growth of p53-deficient K-RasG12V-induced lung cancer by induction of telomeric DNA damage. EMBO Mol Med 2016; 7:930-49. [PMID: 25971796 PMCID: PMC4520658 DOI: 10.15252/emmm.201404497] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Telomeres are considered anti-cancer targets, as telomere maintenance above a minimum length is necessary for cancer growth. Telomerase abrogation in cancer-prone mouse models, however, only decreased tumor growth after several mouse generations when telomeres reach a critically short length, and this effect was lost upon p53 mutation. Here, we address whether induction of telomere uncapping by inhibition of the TRF1 shelterin protein can effectively block cancer growth independently of telomere length. We show that genetic Trf1 ablation impairs the growth of p53-null K-RasG12V-induced lung carcinomas and increases mouse survival independently of telomere length. This is accompanied by induction of telomeric DNA damage, apoptosis, decreased proliferation, and G2 arrest. Long-term whole-body Trf1 deletion in adult mice did not impact on mouse survival and viability, although some mice showed a moderately decreased cellularity in bone marrow and blood. Importantly, inhibition of TRF1 binding to telomeres by small molecules blocks the growth of already established lung carcinomas without affecting mouse survival or tissue function. Thus, induction of acute telomere uncapping emerges as a potential new therapeutic target for lung cancer.
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Affiliation(s)
- María García-Beccaria
- Telomeres and Telomerase Group, Molecular Oncology Program, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
| | - Paula Martínez
- Telomeres and Telomerase Group, Molecular Oncology Program, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
| | - Marinela Méndez-Pertuz
- Telomeres and Telomerase Group, Molecular Oncology Program, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
| | - Sonia Martínez
- Experimental Therapeutics Program, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
| | - Carmen Blanco-Aparicio
- Experimental Therapeutics Program, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
| | - Marta Cañamero
- Histopathology Unit, Biotechnology Program, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
| | - Francisca Mulero
- Molecular Imaging Unit, Biotechnology Program, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
| | - Chiara Ambrogio
- Experimental Oncology, Molecular Oncology Program, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
| | - Juana M Flores
- Animal Surgery and Medicine Department, Faculty of Veterinary Science, Complutense University of Madrid, Madrid, Spain
| | - Diego Megias
- Microscopy Unit, Biotechnology Program, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
| | - Mariano Barbacid
- Molecular Imaging Unit, Biotechnology Program, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
| | - Joaquín Pastor
- Experimental Therapeutics Program, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
| | - Maria A Blasco
- Telomeres and Telomerase Group, Molecular Oncology Program, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
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18
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Benarroch-Popivker D, Pisano S, Mendez-Bermudez A, Lototska L, Kaur P, Bauwens S, Djerbi N, Latrick CM, Fraisier V, Pei B, Gay A, Jaune E, Foucher K, Cherfils-Vicini J, Aeby E, Miron S, Londoño-Vallejo A, Ye J, Le Du MH, Wang H, Gilson E, Giraud-Panis MJ. TRF2-Mediated Control of Telomere DNA Topology as a Mechanism for Chromosome-End Protection. Mol Cell 2016; 61:274-86. [PMID: 26774283 DOI: 10.1016/j.molcel.2015.12.009] [Citation(s) in RCA: 110] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Revised: 10/14/2015] [Accepted: 11/30/2015] [Indexed: 02/07/2023]
Abstract
The shelterin proteins protect telomeres against activation of the DNA damage checkpoints and recombinational repair. We show here that a dimer of the shelterin subunit TRF2 wraps ∼ 90 bp of DNA through several lysine and arginine residues localized around its homodimerization domain. The expression of a wrapping-deficient TRF2 mutant, named Top-less, alters telomeric DNA topology, decreases the number of terminal loops (t-loops), and triggers the ATM checkpoint, while still protecting telomeres against non-homologous end joining (NHEJ). In Top-less cells, the protection against NHEJ is alleviated if the expression of the TRF2-interacting protein RAP1 is reduced. We conclude that a distinctive topological state of telomeric DNA, controlled by the TRF2-dependent DNA wrapping and linked to t-loop formation, inhibits both ATM activation and NHEJ. The presence of RAP1 at telomeres appears as a backup mechanism to prevent NHEJ when topology-mediated telomere protection is impaired.
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Affiliation(s)
- Delphine Benarroch-Popivker
- Institute for Research on Cancer and Aging, Nice (IRCAN), Faculty of Medicine, CNRS UMR7284, INSERM U1081, University of Nice Sophia Antipolis, Nice, France
| | - Sabrina Pisano
- Institute for Research on Cancer and Aging, Nice (IRCAN), Faculty of Medicine, CNRS UMR7284, INSERM U1081, University of Nice Sophia Antipolis, Nice, France
| | - Aaron Mendez-Bermudez
- Institute for Research on Cancer and Aging, Nice (IRCAN), Faculty of Medicine, CNRS UMR7284, INSERM U1081, University of Nice Sophia Antipolis, Nice, France; International Laboratory in Hematology and Cancer, Shanghai Jiao Tong University School of Medicine/Ruijin Hospital/CNRS/INSERM/Nice University, Pôle Sino-Français de Recherche en Sciences du Vivant et Génomique, Shanghai Ruijin Hospital, Huangpu, Shanghai 200025, P.R. China
| | - Liudmyla Lototska
- Institute for Research on Cancer and Aging, Nice (IRCAN), Faculty of Medicine, CNRS UMR7284, INSERM U1081, University of Nice Sophia Antipolis, Nice, France
| | - Parminder Kaur
- Physics Department, North Carolina State University at Raleigh, Raleigh, NC 27695, USA
| | - Serge Bauwens
- Institute for Research on Cancer and Aging, Nice (IRCAN), Faculty of Medicine, CNRS UMR7284, INSERM U1081, University of Nice Sophia Antipolis, Nice, France
| | - Nadir Djerbi
- Institute for Research on Cancer and Aging, Nice (IRCAN), Faculty of Medicine, CNRS UMR7284, INSERM U1081, University of Nice Sophia Antipolis, Nice, France
| | - Chrysa M Latrick
- Institute for Research on Cancer and Aging, Nice (IRCAN), Faculty of Medicine, CNRS UMR7284, INSERM U1081, University of Nice Sophia Antipolis, Nice, France
| | - Vincent Fraisier
- Cell and Tissue Imaging Platform (PICT-IBiSA), Nikon Imaging Centre, UMR 144 CNRS Institut Curie, 75248 Paris Cedex 05, France
| | - Bei Pei
- Institute for Research on Cancer and Aging, Nice (IRCAN), Faculty of Medicine, CNRS UMR7284, INSERM U1081, University of Nice Sophia Antipolis, Nice, France
| | - Alexandre Gay
- Institute for Research on Cancer and Aging, Nice (IRCAN), Faculty of Medicine, CNRS UMR7284, INSERM U1081, University of Nice Sophia Antipolis, Nice, France
| | - Emilie Jaune
- Institute for Research on Cancer and Aging, Nice (IRCAN), Faculty of Medicine, CNRS UMR7284, INSERM U1081, University of Nice Sophia Antipolis, Nice, France
| | - Kevin Foucher
- Institute for Research on Cancer and Aging, Nice (IRCAN), Faculty of Medicine, CNRS UMR7284, INSERM U1081, University of Nice Sophia Antipolis, Nice, France
| | - Julien Cherfils-Vicini
- Institute for Research on Cancer and Aging, Nice (IRCAN), Faculty of Medicine, CNRS UMR7284, INSERM U1081, University of Nice Sophia Antipolis, Nice, France
| | - Eric Aeby
- Swiss Institute for Experimental Cancer Research (ISREC), School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Simona Miron
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Bâtiment 144, CEA Saclay, Gif-sur-Yvette F-91191, France
| | | | - Jing Ye
- International Laboratory in Hematology and Cancer, Shanghai Jiao Tong University School of Medicine/Ruijin Hospital/CNRS/INSERM/Nice University, Pôle Sino-Français de Recherche en Sciences du Vivant et Génomique, Shanghai Ruijin Hospital, Huangpu, Shanghai 200025, P.R. China
| | - Marie-Hélène Le Du
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Bâtiment 144, CEA Saclay, Gif-sur-Yvette F-91191, France
| | - Hong Wang
- Physics Department, North Carolina State University at Raleigh, Raleigh, NC 27695, USA
| | - Eric Gilson
- Institute for Research on Cancer and Aging, Nice (IRCAN), Faculty of Medicine, CNRS UMR7284, INSERM U1081, University of Nice Sophia Antipolis, Nice, France; International Laboratory in Hematology and Cancer, Shanghai Jiao Tong University School of Medicine/Ruijin Hospital/CNRS/INSERM/Nice University, Pôle Sino-Français de Recherche en Sciences du Vivant et Génomique, Shanghai Ruijin Hospital, Huangpu, Shanghai 200025, P.R. China; Department of Genetics, CHU Nice, Nice 06202, France.
| | - Marie-Josèphe Giraud-Panis
- Institute for Research on Cancer and Aging, Nice (IRCAN), Faculty of Medicine, CNRS UMR7284, INSERM U1081, University of Nice Sophia Antipolis, Nice, France.
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19
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Martín M, Terradas M, Hernández L, Genescà A. γH2AX foci on apparently intact mitotic chromosomes: not signatures of misrejoining events but signals of unresolved DNA damage. Cell Cycle 2015; 13:3026-36. [PMID: 25486563 DOI: 10.4161/15384101.2014.947786] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The presence of γH2AX foci on apparently intact mitotic chromosomes is controversial because they challenge the assumed relationship between γH2AX foci and DNA double-strand breaks (DSBs). In this work, we show that after irradiation during interphase, a variety of γH2AX foci are scored in mitotic cells. Surprisingly, approximately 80% of the γH2AX foci spread over apparently undamaged chromatin at Terminal or Interstitial positions and they can display variable sizes, thus being classified as Small, Medium and Big foci. Chromosome and chromatid breaks that reach mitosis are spotted with Big (60%) and Medium (30%) Terminal γH2AX foci, but very rarely are they signaled with Small γH2AX foci. To evaluate if Interstitial γH2AX foci might be signatures of misrejoining, an mFISH analysis was performed on the same slides. The results show that Interstitial γH2AX foci lying on apparently intact chromatin do not mark sites of misrejoining, and that misrejoined events were never signaled by a γH2AX foci during mitosis. Finally, when analyzing the presence of other DNA-damage response (DDR) factors we found that all γH2AX foci-regardless their coincidence with a visible break-always colocalized with MRE11, but not with 53BP1. This pattern suggests that these γH2AX foci may be hallmarks of both microscopically visible and invisible DNA damage, in which an active, although incomplete or halted DDR is taking place.
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Affiliation(s)
- Marta Martín
- a Department of Cell Biology, Immunology, and Neuroscience ; Autonomous University of Barcelona ; Barcelona , Spain
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20
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Badie S, Carlos AR, Folio C, Okamoto K, Bouwman P, Jonkers J, Tarsounas M. BRCA1 and CtIP promote alternative non-homologous end-joining at uncapped telomeres. EMBO J 2015; 34:410-24. [PMID: 25582120 PMCID: PMC4339125 DOI: 10.15252/embj.201488947] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Revised: 10/29/2014] [Accepted: 11/25/2014] [Indexed: 12/15/2022] Open
Abstract
Loss of telomere protection occurs during physiological cell senescence and ageing, due to attrition of telomeric repeats and insufficient retention of the telomere-binding factor TRF2. Subsequently formed telomere fusions trigger rampant genomic instability leading to cell death or tumorigenesis. Mechanistically, telomere fusions require either the classical non-homologous end-joining (C-NHEJ) pathway dependent on Ku70/80 and LIG4, or the alternative non-homologous end-joining (A-NHEJ), which relies on PARP1 and LIG3. Here, we show that the tumour suppressor BRCA1, together with its interacting partner CtIP, both acting in end resection, also promotes end-joining of uncapped telomeres. BRCA1 and CtIP do not function in the ATM-dependent telomere damage signalling, nor in telomere overhang removal, which are critical for telomere fusions by C-NHEJ. Instead, BRCA1 and CtIP act in the same pathway as LIG3 to promote joining of de-protected telomeres by A-NHEJ. Our work therefore ascribes novel roles for BRCA1 and CtIP in end-processing and fusion reactions at uncapped telomeres, underlining the complexity of DNA repair pathways that act at chromosome ends lacking protective structures. Moreover, A-NHEJ provides a mechanism of previously unanticipated significance in telomere dysfunction-induced genome instability.
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Affiliation(s)
- Sophie Badie
- Telomere and Genome Stability Group, The CR-UK/MRC Gray Institute for Radiation Oncology and Biology, Oxford, UK
| | - Ana Rita Carlos
- Telomere and Genome Stability Group, The CR-UK/MRC Gray Institute for Radiation Oncology and Biology, Oxford, UK
| | - Cecilia Folio
- Telomere and Genome Stability Group, The CR-UK/MRC Gray Institute for Radiation Oncology and Biology, Oxford, UK
| | - Keiji Okamoto
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, CA, USA
| | - Peter Bouwman
- Division of Molecular Pathology and Cancer Systems Biology Centre, The Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - Jos Jonkers
- Division of Molecular Pathology and Cancer Systems Biology Centre, The Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - Madalena Tarsounas
- Telomere and Genome Stability Group, The CR-UK/MRC Gray Institute for Radiation Oncology and Biology, Oxford, UK
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21
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Nones K, Waddell N, Wayte N, Patch AM, Bailey P, Newell F, Holmes O, Fink JL, Quinn MCJ, Tang YH, Lampe G, Quek K, Loffler KA, Manning S, Idrisoglu S, Miller D, Xu Q, Waddell N, Wilson PJ, Bruxner TJC, Christ AN, Harliwong I, Nourse C, Nourbakhsh E, Anderson M, Kazakoff S, Leonard C, Wood S, Simpson PT, Reid LE, Krause L, Hussey DJ, Watson DI, Lord RV, Nancarrow D, Phillips WA, Gotley D, Smithers BM, Whiteman DC, Hayward NK, Campbell PJ, Pearson JV, Grimmond SM, Barbour AP. Genomic catastrophes frequently arise in esophageal adenocarcinoma and drive tumorigenesis. Nat Commun 2014; 5:5224. [PMID: 25351503 PMCID: PMC4596003 DOI: 10.1038/ncomms6224] [Citation(s) in RCA: 198] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2014] [Accepted: 09/09/2014] [Indexed: 12/30/2022] Open
Abstract
Oesophageal adenocarcinoma (EAC) incidence is rapidly increasing in Western countries. A better understanding of EAC underpins efforts to improve early detection and treatment outcomes. While large EAC exome sequencing efforts to date have found recurrent loss-of-function mutations, oncogenic driving events have been underrepresented. Here we use a combination of whole-genome sequencing (WGS) and single-nucleotide polymorphism-array profiling to show that genomic catastrophes are frequent in EAC, with almost a third (32%, n=40/123) undergoing chromothriptic events. WGS of 22 EAC cases show that catastrophes may lead to oncogene amplification through chromothripsis-derived double-minute chromosome formation (MYC and MDM2) or breakage-fusion-bridge (KRAS, MDM2 and RFC3). Telomere shortening is more prominent in EACs bearing localized complex rearrangements. Mutational signature analysis also confirms that extreme genomic instability in EAC can be driven by somatic BRCA2 mutations. These findings suggest that genomic catastrophes have a significant role in the malignant transformation of EAC.
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Affiliation(s)
- Katia Nones
- Queensland Centre for Medical Genomics, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia.,QIMR Berghofer Medical Research Institute, Herston, Brisbane, Queensland 4006, Australia
| | - Nicola Waddell
- Queensland Centre for Medical Genomics, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia.,QIMR Berghofer Medical Research Institute, Herston, Brisbane, Queensland 4006, Australia
| | - Nicci Wayte
- Surgical Oncology Group, School of Medicine, The University of Queensland, Translational Research Institute at the Princess Alexandra Hospital, Woolloongabba, Brisbane, Queensland 4102, Australia
| | - Ann-Marie Patch
- Queensland Centre for Medical Genomics, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia
| | - Peter Bailey
- Queensland Centre for Medical Genomics, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia
| | - Felicity Newell
- Queensland Centre for Medical Genomics, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia
| | - Oliver Holmes
- Queensland Centre for Medical Genomics, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia.,QIMR Berghofer Medical Research Institute, Herston, Brisbane, Queensland 4006, Australia
| | - J Lynn Fink
- Queensland Centre for Medical Genomics, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia
| | - Michael C J Quinn
- Queensland Centre for Medical Genomics, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia
| | - Yue Hang Tang
- Surgical Oncology Group, School of Medicine, The University of Queensland, Translational Research Institute at the Princess Alexandra Hospital, Woolloongabba, Brisbane, Queensland 4102, Australia
| | - Guy Lampe
- Department of Anatomical Pathology, Princess Alexandra Hospital, Woolloongabba, Brisbane, Queensland 4102, Australia
| | - Kelly Quek
- Queensland Centre for Medical Genomics, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia
| | - Kelly A Loffler
- Surgical Oncology Group, School of Medicine, The University of Queensland, Translational Research Institute at the Princess Alexandra Hospital, Woolloongabba, Brisbane, Queensland 4102, Australia
| | - Suzanne Manning
- Queensland Centre for Medical Genomics, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia
| | - Senel Idrisoglu
- Queensland Centre for Medical Genomics, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia
| | - David Miller
- Queensland Centre for Medical Genomics, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia
| | - Qinying Xu
- Queensland Centre for Medical Genomics, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia.,QIMR Berghofer Medical Research Institute, Herston, Brisbane, Queensland 4006, Australia
| | - Nick Waddell
- Queensland Centre for Medical Genomics, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia
| | - Peter J Wilson
- Queensland Centre for Medical Genomics, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia
| | - Timothy J C Bruxner
- Queensland Centre for Medical Genomics, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia
| | - Angelika N Christ
- Queensland Centre for Medical Genomics, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia
| | - Ivon Harliwong
- Queensland Centre for Medical Genomics, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia
| | - Craig Nourse
- Queensland Centre for Medical Genomics, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia
| | - Ehsan Nourbakhsh
- Queensland Centre for Medical Genomics, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia
| | - Matthew Anderson
- Queensland Centre for Medical Genomics, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia
| | - Stephen Kazakoff
- Queensland Centre for Medical Genomics, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia
| | - Conrad Leonard
- Queensland Centre for Medical Genomics, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia.,QIMR Berghofer Medical Research Institute, Herston, Brisbane, Queensland 4006, Australia
| | - Scott Wood
- Queensland Centre for Medical Genomics, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia.,QIMR Berghofer Medical Research Institute, Herston, Brisbane, Queensland 4006, Australia
| | - Peter T Simpson
- QIMR Berghofer Medical Research Institute, Herston, Brisbane, Queensland 4006, Australia.,The University of Queensland, UQ Centre for Clinical Research, Herston, Brisbane, Queensland 4029, Australia.,The University of Queensland, School of Medicine, Herston, Queensland 4006, Australia
| | - Lynne E Reid
- QIMR Berghofer Medical Research Institute, Herston, Brisbane, Queensland 4006, Australia.,The University of Queensland, UQ Centre for Clinical Research, Herston, Brisbane, Queensland 4029, Australia
| | - Lutz Krause
- QIMR Berghofer Medical Research Institute, Herston, Brisbane, Queensland 4006, Australia
| | - Damian J Hussey
- Flinders University Department of Surgery, Flinders Medical Centre, Bedford Park, South Australia 5042, Australia
| | - David I Watson
- Flinders University Department of Surgery, Flinders Medical Centre, Bedford Park, South Australia 5042, Australia
| | - Reginald V Lord
- St Vincent's Centre for Applied Medical Research, University of Notre Dame and University of New South Wales, Sydney, New South Wales 2011, Australia
| | - Derek Nancarrow
- QIMR Berghofer Medical Research Institute, Herston, Brisbane, Queensland 4006, Australia
| | - Wayne A Phillips
- Cancer Research Division, Peter MacCallum Cancer Centre, East Melbourne, Victoria 3002, Australia
| | - David Gotley
- Department of Surgery, School of Medicine, The University of Queensland, Princess Alexandra Hospital, Woolloongabba, Brisbane, Queensland 4102, Australia
| | - B Mark Smithers
- Department of Surgery, School of Medicine, The University of Queensland, Princess Alexandra Hospital, Woolloongabba, Brisbane, Queensland 4102, Australia
| | - David C Whiteman
- QIMR Berghofer Medical Research Institute, Herston, Brisbane, Queensland 4006, Australia
| | - Nicholas K Hayward
- QIMR Berghofer Medical Research Institute, Herston, Brisbane, Queensland 4006, Australia
| | - Peter J Campbell
- Cancer Genome Project, Wellcome Trust Sanger Institute, Hinxton, Cambridgeshire CB10 1SA, UK
| | - John V Pearson
- Queensland Centre for Medical Genomics, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia.,QIMR Berghofer Medical Research Institute, Herston, Brisbane, Queensland 4006, Australia
| | - Sean M Grimmond
- Queensland Centre for Medical Genomics, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia.,Wolfson Wohl Cancer Research Centre, Institute for Cancer Sciences, University of Glasgow, Garscube Estate, Switchback Road, Bearsden, Glasgow G61 1BD, UK
| | - Andrew P Barbour
- Surgical Oncology Group, School of Medicine, The University of Queensland, Translational Research Institute at the Princess Alexandra Hospital, Woolloongabba, Brisbane, Queensland 4102, Australia.,Department of Surgery, School of Medicine, The University of Queensland, Princess Alexandra Hospital, Woolloongabba, Brisbane, Queensland 4102, Australia
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22
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Silva BA, Stambaugh JR, Yokomori K, Shah JV, Berns MW. DNA damage to a single chromosome end delays anaphase onset. J Biol Chem 2014; 289:22771-22784. [PMID: 24982423 DOI: 10.1074/jbc.m113.535955] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Chromosome ends contain nucleoprotein structures known as telomeres. Damage to chromosome ends during interphase elicits a DNA damage response (DDR) resulting in cell cycle arrest. However, little is known regarding the signaling from damaged chromosome ends (designated here as "TIPs") during mitosis. In the present study, we investigated the consequences of DNA damage induced at a single TIP in mitosis. We used laser microirradiation to damage mitotic TIPs or chromosome arms (non-TIPs) in PtK2 kidney epithelial cells. We found that damage to a single TIP, but not a non-TIP, delays anaphase onset. This TIP-specific checkpoint response is accompanied by differential recruitment of DDR proteins. Although phosphorylation of H2AX and the recruitment of several repair factors, such as Ku70-Ku80, occur in a comparable manner at both TIP and non-TIP damage sites, DDR factors such as ataxia telangiectasia mutated (ATM), MDC1, WRN, and FANCD2 are specifically recruited to TIPs but not to non-TIPs. In addition, Nbs1, BRCA1, and ubiquitin accumulate at damaged TIPs more rapidly than at damaged non-TIPs. ATR and 53BP1 are not detected at either TIPs or non-TIPs in mitosis. The observed delay in anaphase onset is dependent on the activity of DDR kinases ATM and Chk1, and the spindle assembly checkpoint kinase Mps1. Cells damaged at a single TIP or non-TIP eventually exit mitosis with unrepaired lesions. Damaged TIPs are segregated into micronuclei at a significantly higher frequency than damaged non-TIPs. Together, these findings reveal a mitosis-specific DDR uniquely associated with chromosome ends.
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Affiliation(s)
- Bárbara Alcaraz Silva
- Beckman Laser Institute and Medical Clinic, Irvine, California 92612,; Department of Developmental and Cell Biology, School of Biological Sciences, University of California, Irvine, California 92617
| | | | - Kyoko Yokomori
- Department of Biological Chemistry, School of Medicine, University of California, Irvine, California 92697-1700, and.
| | - Jagesh V Shah
- Department of Systems Biology, Harvard Medical School and Renal Division, Brigham and Women's Hospital, Boston, Massachusetts 02115.
| | - Michael W Berns
- Beckman Laser Institute and Medical Clinic, Irvine, California 92612,; Department of Developmental and Cell Biology, School of Biological Sciences, University of California, Irvine, California 92617,; Department of Biomedical Engineering, University of California, Irvine, California 92617,.
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23
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Lee K, Gollahon LS. Zscan4 interacts directly with human Rap1 in cancer cells regardless of telomerase status. Cancer Biol Ther 2014; 15:1094-105. [PMID: 24840609 DOI: 10.4161/cbt.29220] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Telomeres are repetitive sequences at the ends of chromosomes protected by DNA binding proteins of the shelterin complex that form capping structures. Through the interaction of shelterin complex-associated proteins, telomere length maintenance is regulated. Recently, the newly identified embryonic stem cell marker, Zinc finger and SCAN domain-containing 4 gene (Zscan4), was shown to be a telomere-associated protein, co-localizing to the shelterin complex. Furthermore, it was shown to play an essential role in genomic stability by regulating telomere elongation. Although it is known that Zscan4 regulates TRF2, POT1b, and Rap1 expression in embryonic stem cells, the relationship and the exact mechanism of action for ZSscan4-mediated telomere maintenance in cancer cells is unknown. In this study, we investigated Zscan4 expression and interactions with Rap1 in telomerase positive (HeLa, MCF7) and ALT pathway (SaOS2, U2OS) cancer cells. Through western, pulldown, siRNA, and overexpression assays we demonstrate, for the first time, that Zscan4 directly associates with Rap1 (physical association protein). Furthermore, by generating truncated versions of Zscan4, we identified its zinc finger domain as the Rap1 binding site. Using bimolecular fluorescence complementation, we further validate this functional interaction in human cancer cells. Our results indicate that Zscan4 functions as a mediator of telomere length through its direct interaction with Rap1, possibly regulating shelterin complex-controlled telomere elongation in both telomerase positive and alternative lengthening of telomere pathways. This direct interaction between Zscan4 and Rap1 may explain how Zscan4 rapidly increases telomere length, yielding important information about the role of these proteins in telomere biology.
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Affiliation(s)
- Kyungwoo Lee
- Department of Biological Sciences; Texas Tech University; Lubbock, TX USA
| | - Lauren S Gollahon
- Department of Biological Sciences; Texas Tech University; Lubbock, TX USA; Texas Tech University Imaging Center; Lubbock, TX USA
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24
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Jones M, Osawa G, Regal JA, Weinberg DN, Taggart J, Kocak H, Friedman A, Ferguson DO, Keegan CE, Maillard I. Hematopoietic stem cells are acutely sensitive to Acd shelterin gene inactivation. J Clin Invest 2013; 124:353-66. [PMID: 24316971 DOI: 10.1172/jci67871] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2013] [Accepted: 10/03/2013] [Indexed: 12/26/2022] Open
Abstract
The shelterin complex plays dual functions in telomere homeostasis by recruiting telomerase and preventing the activation of a DNA damage response at telomeric ends. Somatic stem cells require telomerase activity, as evidenced by progressive stem cell loss leading to bone marrow failure in hereditary dyskeratosis congenita. Recent work demonstrates that dyskeratosis congenita can also arise from mutations in specific shelterin genes, although little is known about shelterin functions in somatic stem cells. We found that mouse hematopoietic stem cells (HSCs) are acutely sensitive to inactivation of the shelterin gene Acd, encoding TPP1. Homozygosity for a hypomorphic acd allele preserved the emergence and expansion of fetal HSCs but led to profoundly defective function in transplantation assays. Upon complete Acd inactivation, HSCs expressed p53 target genes, underwent cell cycle arrest, and were severely depleted within days, leading to hematopoietic failure. TPP1 loss induced increased telomeric fusion events in bone marrow progenitors. However, unlike in epidermal stem cells, p53 deficiency did not rescue TPP1-deficient HSCs, indicating that shelterin dysfunction has unique effects in different stem cell populations. Because the consequences of telomere shortening are progressive and unsynchronized, acute loss of shelterin function represents an attractive alternative for studying telomere crisis in hematopoietic progenitors.
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25
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Jullien L, Mestre M, Roux P, Gire V. Eroded human telomeres are more prone to remain uncapped and to trigger a G2 checkpoint response. Nucleic Acids Res 2012. [PMID: 23193277 PMCID: PMC3553962 DOI: 10.1093/nar/gks1121] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Telomeres cap the ends of chromosomes and regulate the replicative life span of human somatic cells. Telomere function is lost upon critical shortening and a p53-dependent checkpoint that detects altered telomere states at the G1/S transition was proposed to act as a regulator of the telomere damage response. We show that telomerase-negative human fibroblasts spend more time in G2 phase as they approach senescence and this delay is associated with manifestations of telomere dysfunction and the triggering of an ATM/ATR-dependent DNA damage signal. This correlates with a partial release of telomeric proteins TRF1 and TRF2. Analysis of the consequences of TRF1 and TRF2 depletion or over-expression of mutated versions revealed that telomere uncapping or telomere replication stress also led to DNA damage signalling in G2. Progression through mitosis of these cells was associated with signs of incomplete telomere terminal processing. We also observed an increase in sister chromatid-type telomere aberrations in senescing fibroblasts indicating that defects of telomere post-replicative events increased as cells age. Our results link a post-replicative damage response at eroded telomeres to G2 arrest signalling and challenge the current paradigm that the checkpoint response to short telomeres occurs primarily at the G1/S transition in human cells.
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Affiliation(s)
- Laurent Jullien
- Universités Montpellier 2 et 1, CRBM-CNRS UMR 5237, 1919, route de Mende, 34293 Montpellier, France
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26
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Hao XD, Yang Y, Song X, Zhao XK, Wang LD, He JD, Kong QP, Tang NLS, Zhang YP. Correlation of telomere length shortening with TP53 somatic mutations, polymorphisms and allelic loss in breast tumors and esophageal cancer. Oncol Rep 2012; 29:226-36. [PMID: 23124483 DOI: 10.3892/or.2012.2098] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2012] [Accepted: 09/07/2012] [Indexed: 11/05/2022] Open
Abstract
Genomic instability caused by telomere erosion is an important mechanism of tumorigenesis. p53 plays a key role in cellular senescence and/or apoptosis associated with telomere erosion which positions p53 as a guard against tumorigenesis. The present study was undertaken to investigate the potential interactions between p53 functional mutations, polymorphisms, allelic loss and telomere erosion in 126 breast tumor patients and 68 esophageal cancer patients. Telomere length (TL) was measured by real-time quantitative PCR. Somatic mutations, polymorphisms and allelic loss in the TP53 gene were detected by direct sequencing of both tumor and normal tissue samples. Our results showed that telomeres were significantly shorter in tumors with somatic p53 mutations compared with tumors with wild-type p53 in both breast tumors (P=0.007) and esophageal cancer (P=0.001). Telomeres of patients with minor genotype CC of rs12951053 and GG of rs1042522 were significantly shorter compared to patients with other genotypes of this single nucleotide polymorphism in esophageal cancer tissue. Furthermore, TP53 allelic loss was detected and significantly associated with somatic mutations in both types of tumor tissues. These findings suggest that somatic p53 mutations, rs12951053 genotype CC and rs1042522 genotype GG contribute to erosion of telomeres, and TP53 allelic loss may be one of the representations of chromosomal instability caused by telomere erosion combined with somatic p53 mutations. These results support that the TP53 gene has a strong interaction with TL erosion in tumorigenesis.
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Affiliation(s)
- Xiao-Dan Hao
- State Key Laboratory of Genetic Resources and Evolution, and Yunnan Laboratory of Molecular Biology of Domestic Animals, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, PR China
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27
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Cesare AJ, Karlseder J. A three-state model of telomere control over human proliferative boundaries. Curr Opin Cell Biol 2012; 24:731-8. [PMID: 22947495 DOI: 10.1016/j.ceb.2012.08.007] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2012] [Revised: 07/27/2012] [Accepted: 08/20/2012] [Indexed: 12/15/2022]
Abstract
Intrinsic limits on cellular proliferation in human somatic tissue serves as a tumor suppressor mechanism by restricting cell growth in aged cells with accrued pre-cancerous mutations. This is accompanied by the potential cost of restricting regenerative capacity and contributing to cellular and organismal aging. Emerging data support a model where telomere erosion controls proliferative boundaries through the progressive change of telomere structure from a protected state, through two distinct states of telomere deprotection. In this model telomeres facilitate a controlled permanent cell cycle arrest with a stable diploid genome during differentiation and may serve as an epigenetic sensor of general stress in DNA metabolism processes.
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Affiliation(s)
- Anthony J Cesare
- The Salk Institute for Biological Studies, Molecular and Cell Biology Laboratory, 10010 North Torrey Pines Rd., La Jolla, CA 92037, USA
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28
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Thanasoula M, Escandell JM, Suwaki N, Tarsounas M. ATM/ATR checkpoint activation downregulates CDC25C to prevent mitotic entry with uncapped telomeres. EMBO J 2012; 31:3398-410. [PMID: 22842784 PMCID: PMC3419928 DOI: 10.1038/emboj.2012.191] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2012] [Accepted: 06/20/2012] [Indexed: 02/02/2023] Open
Abstract
Shelterin component TRF2 prevents ATM activation, while POT1 represses ATR signalling at telomeres. Here, we investigate the mechanism of G2/M arrest triggered by telomeres uncapped through TRF2 or POT1 inhibition in human cells. We find that telomere damage-activated ATR and ATM phosphorylate p53, as well as CHK1 and CHK2, thus activating two independent pathways to prevent progression into mitosis with uncapped telomeres. Surprisingly, telomere damage targets the CDC25C phosphatase for proteasome degradation in G2/M. CHK1/CHK2-dependent phosphorylation of CDC25C at Ser 216 is required for CDC25C nuclear export and destruction, which in turn acts to sustain the G2/M arrest elicited by TRF2- or POT1-depleted telomeres. In addition, CDC25C is transcriptionally downregulated by p53 in response to telomere damage. These mechanisms are distinct from the canonical DNA damage response to ionizing radiation, which triggers cell-cycle arrest through CDC25A destruction. Thus, dysfunctional telomeres promote ATM/ATR-dependent degradation of CDC25C phosphatase to block mitotic entry, thereby preventing telomere dysfunction-driven genomic instability.
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Affiliation(s)
- Maria Thanasoula
- Telomere and Genome Stability Group, The CR-UK/MRC Gray Institute for Radiation Oncology and Biology, Department of Oncology, University of Oxford, Oxford, UK
| | - Jose Miguel Escandell
- Telomere and Genome Stability Group, The CR-UK/MRC Gray Institute for Radiation Oncology and Biology, Department of Oncology, University of Oxford, Oxford, UK
| | - Natsuko Suwaki
- Telomere and Genome Stability Group, The CR-UK/MRC Gray Institute for Radiation Oncology and Biology, Department of Oncology, University of Oxford, Oxford, UK
| | - Madalena Tarsounas
- Telomere and Genome Stability Group, The CR-UK/MRC Gray Institute for Radiation Oncology and Biology, Department of Oncology, University of Oxford, Oxford, UK
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29
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Akbay EA, Peña CG, Ruder D, Michel JA, Nakada Y, Pathak S, Multani AS, Chang S, Castrillon DH. Cooperation between p53 and the telomere-protecting shelterin component Pot1a in endometrial carcinogenesis. Oncogene 2012; 32:2211-9. [PMID: 22689059 PMCID: PMC3636499 DOI: 10.1038/onc.2012.232] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Type II endometrial cancer (EMCA) represents only 10% of all EMCAs, but accounts for 40% of EMCA-related mortality. Previous studies of human tumors have shown an association between Type II tumors and damaged telomeres. We hypothesized that the lack of murine Type II EMCA models is due to the extremely long telomeres in laboratory mouse strains. We previously showed that telomerase-null mice with critically short telomeres developed endometrial lesions histologically resembling endometrial intraepithelial carcinoma (EIC), the accepted precursor for Type II EMCA. However, these mice did not develop invasive endometrial adenocarcinoma, and instead succumbed prematurely to multi-organ failure. Here, we modeled critical telomere attrition by conditionally inactivating Pot1a, a component of the shelterin complex that stabilizes telomeres, within endometrial epithelium. Inactivation of Pot1a by itself did not stimulate endometrial carcinogenesis, and did not result in detectable DNA damage or apoptosis in endometrium. However, simultaneous inactivation of Pot1a and p53 resulted in EIC-like lesions by 9 months indistinguishable from those seen in late generation telomerase-null mice. These lesions progressed to invasive endometrial adenocarcinomas as early as 9 months of age with metastatic disease in 100% of the animals by 15 months. These tumors were poorly differentiated endometrial adenocarcinomas with prominent nuclear atypia, resembling human Type II cancers. Furthermore, these tumors were aneuploid with double-stranded DNA breaks and end-to-end telomere fusions and most were tetraploid or near-tetraploid. These studies lend further support to the hypothesis that telomeric instability has a critical role in Type II endometrial carcinogenesis and provides an intriguing in-vivo correlate to recent studies implicating telomere-dependent tetraploidization as an important mechanism in carcinogenesis.
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Affiliation(s)
- E A Akbay
- Department of Pathology, UT Southwestern Medical Center, Dallas, TX 75390–9072, USA
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30
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Martínez P, Flores JM, Blasco MA. 53BP1 deficiency combined with telomere dysfunction activates ATR-dependent DNA damage response. ACTA ACUST UNITED AC 2012; 197:283-300. [PMID: 22508511 PMCID: PMC3328378 DOI: 10.1083/jcb.201110124] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Loss of the telomere component TRF1 and the DNA repair mediator 53BP1 enhances the ATR-mediated DNA damage response, promotes the homology-directed repair of dysfunctional telomeres, and exacerbates DNA damage. TRF1 protects mammalian telomeres from fusion and fragility. Depletion of TRF1 leads to telomere fusions as well as accumulation of γ-H2AX foci and activation of both the ataxia telangiectasia mutated (ATM)– and the ataxia telangiectasia and Rad3 related (ATR)–mediated deoxyribonucleic acid (DNA) damage response (DDR) pathways. 53BP1, which is also present at dysfunctional telomeres, is a target of ATM that accumulates at DNA double-strand breaks and favors nonhomologous end-joining (NHEJ) repair over ATM-dependent resection and homology-directed repair (homologous recombination [HR]). To address the role of 53BP1 at dysfunctional telomeres, we generated mice lacking TRF1 and 53BP1. 53BP1 deficiency significantly rescued telomere fusions in mouse embryonic fibroblasts (MEFs) lacking TRF1, but they showed evidence of a switch from the NHEJ- to HR-mediated repair of uncapped telomeres. Concomitantly, double-mutant MEFs showed evidence of hyperactivation of the ATR-dependent DDR. In intact mice, combined 53BP1/TRF1 deficiency in stratified epithelia resulted in earlier onset of DNA damage and increased CHK1 phosphorylation during embryonic development, leading to aggravation of skin phenotypes.
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Affiliation(s)
- Paula Martínez
- Telomeres and Telomerase Group, Molecular Oncology Programme, Spanish National Cancer Research Centre, E-28029 Madrid, Spain
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31
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Gu P, Min JN, Wang Y, Huang C, Peng T, Chai W, Chang S. CTC1 deletion results in defective telomere replication, leading to catastrophic telomere loss and stem cell exhaustion. EMBO J 2012; 31:2309-21. [PMID: 22531781 DOI: 10.1038/emboj.2012.96] [Citation(s) in RCA: 127] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2012] [Accepted: 03/21/2012] [Indexed: 11/09/2022] Open
Abstract
The proper maintenance of telomeres is essential for genome stability. Mammalian telomere maintenance is governed by a number of telomere binding proteins, including the newly identified CTC1-STN1-TEN1 (CST) complex. However, the in vivo functions of mammalian CST remain unclear. To address this question, we conditionally deleted CTC1 from mice. We report here that CTC1 null mice experience rapid onset of global cellular proliferative defects and die prematurely from complete bone marrow failure due to the activation of an ATR-dependent G2/M checkpoint. Acute deletion of CTC1 does not result in telomere deprotection, suggesting that mammalian CST is not involved in capping telomeres. Rather, CTC1 facilitates telomere replication by promoting efficient restart of stalled replication forks. CTC1 deletion results in increased loss of leading C-strand telomeres, catastrophic telomere loss and accumulation of excessive ss telomere DNA. Our data demonstrate an essential role for CTC1 in promoting efficient replication and length maintenance of telomeres.
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Affiliation(s)
- Peili Gu
- Department of Laboratory Medicine and Pathology, Yale University School of Medicine, New Haven, CT 06520-8035, USA
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32
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Rausch T, Jones DTW, Zapatka M, Stütz AM, Zichner T, Weischenfeldt J, Jäger N, Remke M, Shih D, Northcott PA, Pfaff E, Tica J, Wang Q, Massimi L, Witt H, Bender S, Pleier S, Cin H, Hawkins C, Beck C, von Deimling A, Hans V, Brors B, Eils R, Scheurlen W, Blake J, Benes V, Kulozik AE, Witt O, Martin D, Zhang C, Porat R, Merino DM, Wasserman J, Jabado N, Fontebasso A, Bullinger L, Rücker FG, Döhner K, Döhner H, Koster J, Molenaar JJ, Versteeg R, Kool M, Tabori U, Malkin D, Korshunov A, Taylor MD, Lichter P, Pfister SM, Korbel JO. Genome sequencing of pediatric medulloblastoma links catastrophic DNA rearrangements with TP53 mutations. Cell 2012; 148:59-71. [PMID: 22265402 DOI: 10.1016/j.cell.2011.12.013] [Citation(s) in RCA: 650] [Impact Index Per Article: 54.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2011] [Revised: 12/06/2011] [Accepted: 12/07/2011] [Indexed: 10/14/2022]
Abstract
Genomic rearrangements are thought to occur progressively during tumor development. Recent findings, however, suggest an alternative mechanism, involving massive chromosome rearrangements in a one-step catastrophic event termed chromothripsis. We report the whole-genome sequencing-based analysis of a Sonic-Hedgehog medulloblastoma (SHH-MB) brain tumor from a patient with a germline TP53 mutation (Li-Fraumeni syndrome), uncovering massive, complex chromosome rearrangements. Integrating TP53 status with microarray and deep sequencing-based DNA rearrangement data in additional patients reveals a striking association between TP53 mutation and chromothripsis in SHH-MBs. Analysis of additional tumor entities substantiates a link between TP53 mutation and chromothripsis, and indicates a context-specific role for p53 in catastrophic DNA rearrangements. Among these, we observed a strong association between somatic TP53 mutations and chromothripsis in acute myeloid leukemia. These findings connect p53 status and chromothripsis in specific tumor types, providing a genetic basis for understanding particularly aggressive subtypes of cancer.
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Affiliation(s)
- Tobias Rausch
- European Molecular Biology Laboratory, Meyerhofstr. 1, 69117 Heidelberg, Germany
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33
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Stewart JA, Chaiken MF, Wang F, Price CM. Maintaining the end: roles of telomere proteins in end-protection, telomere replication and length regulation. Mutat Res 2012; 730:12-9. [PMID: 21945241 PMCID: PMC3256267 DOI: 10.1016/j.mrfmmm.2011.08.011] [Citation(s) in RCA: 140] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2011] [Revised: 08/15/2011] [Accepted: 08/17/2011] [Indexed: 11/16/2022]
Abstract
Chromosome end protection is essential to protect genome integrity. Telomeres, tracts of repetitive DNA sequence and associated proteins located at the chromosomal terminus, serve to safeguard the ends from degradation and unwanted double strand break repair. Due to the essential nature of telomeres in protecting the genome, a number of unique proteins have evolved to ensure that telomere length and structure are preserved. The inability to properly maintain telomeres can lead to diseases such as dyskeratosis congenita, pulmonary fibrosis and cancer. In this review, we will discuss the known functions of mammalian telomere-associated proteins, their role in telomere replication and length regulation and how these processes relate to genome instability and human disease.
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Affiliation(s)
- Jason A. Stewart
- Department of Cancer and Cell Biology, University of Cincinnati, Cincinnati, Ohio 45267, USA
| | - Mary F. Chaiken
- Department of Cancer and Cell Biology, University of Cincinnati, Cincinnati, Ohio 45267, USA
| | - Feng Wang
- Department of Cancer and Cell Biology, University of Cincinnati, Cincinnati, Ohio 45267, USA
| | - Carolyn M. Price
- Department of Cancer and Cell Biology, University of Cincinnati, Cincinnati, Ohio 45267, USA
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Kibe R, Zhang S, Guo D, Marrero L, Tsien F, Rodriguez P, Khan S, Zieske A, Huang J, Li W, Durum SK, Iwakuma T, Cui Y. IL-7Rα deficiency in p53null mice exacerbates thymocyte telomere erosion and lymphomagenesis. Cell Death Differ 2012; 19:1139-51. [PMID: 22281704 DOI: 10.1038/cdd.2011.203] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Interleukin-7 (IL-7) is an essential T-cell survival cytokine. IL-7 receptor (IL-7Rα) deficiency severely impairs T-cell development due to substantial apoptosis. We hypothesized that IL-7Rα(null)-induced apoptosis is partially contributed by an elevated p53 activity. To investigate the genetic association of IL-7/IL-7Rα signaling with the p53 pathway, we generated IL-7Rα(null)p53(null) (DKO) mice. DKO mice exhibited a marked reduction of apoptosis in developing T cells and an augmented thymic lymphomagenesis with telomere erosions and exacerbated chromosomal anomalies, including chromosome duplications, breaks, and translocations. In particular, Robertsonian translocations, in which telocentric chromosomes fuse at the centromeric region, and a complete loss of telomeres at the fusion site occurred frequently in DKO thymic lymphomas. Cellular and molecular investigations revealed that IL-7/IL-7Rα signaling withdrawal diminished the protein synthesis of protection of telomere 1 (POT1), a subunit of telomere protective complex shelterin, leading to telomere erosion and the activation of the p53 pathway. Blockade of IL-7/IL-7Rα signaling in IL-7-dependent p53(null) cells reduced POT1 expression and caused telomere and chromosome abnormalities similar to those observed in DKO lymphomas. This study underscores a novel function of IL-7/IL-7Rα during T-cell development in regulating telomere integrity via POT1 expression and provides new insights into cytokine-mediated survival signals and T-cell lymphomagenesis.
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Affiliation(s)
- R Kibe
- Louisiana State University Health Sciences Center, Gene Therapy Program, New Orleans, LA 70112, USA
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Cyclin B-dependent kinase 1 regulates human TRF1 to modulate the resolution of sister telomeres. Nat Commun 2011; 2:371. [PMID: 21712819 PMCID: PMC4931922 DOI: 10.1038/ncomms1372] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2011] [Accepted: 06/02/2011] [Indexed: 11/26/2022] Open
Abstract
Cyclin B-Cdk1 is a key mediator of mitotic entry, however little is known about its role in the separation of sister chromatids. Here we report that upon mitotic entry, Cdk1 specifically phosphorylates threonine 371 of TRF1, a telomere binding protein implicated in the regulation of sister telomere cohesion. Such phosphorylation is removed in late mitosis when Cdk1 activity is inhibited, indicative of a tight regulation of T371 phosphorylation. We show that T371 phosphorylation by Cdk1 keeps TRF1 free of chromatin and this phosphorylation is associated with loss of telomere-bound TRF1 and TIN2, and a reduction in telomere heterochromatin. We find that a phosphomimic mutation at T371 of TRF1 induces telomere deprotection, resulting in telomere loss and the formation of telomere fusions whereas a non-phosphorylatable substitution of T371 blocks sister telomere resolution, promotes micronuclei formation and impairs cell proliferation. Our work suggests that Cdk1 controls TRF1 association with telomeres to facilitate temporal telomere de-protection essential for sister telomere resolution.
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36
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Effects of age and heart failure on human cardiac stem cell function. THE AMERICAN JOURNAL OF PATHOLOGY 2011; 179:349-66. [PMID: 21703415 DOI: 10.1016/j.ajpath.2011.03.036] [Citation(s) in RCA: 162] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2010] [Revised: 02/25/2011] [Accepted: 03/03/2011] [Indexed: 12/11/2022]
Abstract
Currently, it is unknown whether defects in stem cell growth and differentiation contribute to myocardial aging and chronic heart failure (CHF), and whether a compartment of functional human cardiac stem cells (hCSCs) persists in the decompensated heart. To determine whether aging and CHF are critical determinants of the loss in growth reserve of the heart, the properties of hCSCs were evaluated in 18 control and 23 explanted hearts. Age and CHF showed a progressive decrease in functionally competent hCSCs. Chronological age was a major predictor of five biomarkers of hCSC senescence: telomeric shortening, attenuated telomerase activity, telomere dysfunction-induced foci, and p21(Cip1) and p16(INK4a) expression. CHF had similar consequences for hCSCs, suggesting that defects in the balance between cardiomyocyte mass and the pool of nonsenescent hCSCs may condition the evolution of the decompensated myopathy. A correlation was found previously between telomere length in circulating bone marrow cells and cardiovascular diseases, but that analysis was restricted to average telomere length in a cell population, neglecting the fact that telomere attrition does not occur uniformly in all cells. The present study provides the first demonstration that dysfunctional telomeres in hCSCs are biomarkers of aging and heart failure. The biomarkers of cellular senescence identified here can be used to define the birth date of hCSCs and to sort young cells with potential therapeutic efficacy.
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37
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BRCA2 acts as a RAD51 loader to facilitate telomere replication and capping. Nat Struct Mol Biol 2010; 17:1461-9. [PMID: 21076401 PMCID: PMC2998174 DOI: 10.1038/nsmb.1943] [Citation(s) in RCA: 127] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2010] [Accepted: 10/01/2010] [Indexed: 12/11/2022]
Abstract
The tumor suppressor protein BRCA2 is a key component of the homologous recombination pathway of DNA repair, acting as the loader of RAD51 recombinase at sites of double-strand breaks. Here we show that BRCA2 associates with telomeres during the S and G2 phases of the cell cycle and facilitates the loading of RAD51 onto telomeres. Conditional deletion of Brca2 and inhibition of Rad51 in mouse embryonic fibroblasts (MEFs), but not inactivation of Brca1, led to shortening of telomeres and accumulation of fragmented telomeric signals--a hallmark of telomere fragility that is associated with replication defects. These findings suggest that BRCA2-mediated homologous recombination reactions contribute to the maintenance of telomere length by facilitating telomere replication and imply that BRCA2 has an essential role in maintaining telomere integrity during unchallenged cell proliferation. Mouse mammary tumors that lacked Brca2 accumulated telomere dysfunction-induced foci. Human breast tumors in which BRCA2 was mutated had shorter telomeres than those in which BRCA1 was mutated, suggesting that the genomic instability in BRCA2-deficient tumors was due in part to telomere dysfunction.
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38
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Baker NM, Zeitlin SG, Shi LZ, Shah J, Berns MW. Chromosome tips damaged in anaphase inhibit cytokinesis. PLoS One 2010; 5:e12398. [PMID: 20811641 PMCID: PMC2928297 DOI: 10.1371/journal.pone.0012398] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2010] [Accepted: 07/27/2010] [Indexed: 12/21/2022] Open
Abstract
Genome maintenance is ensured by a variety of biochemical sensors and pathways that repair accumulated damage. During mitosis, the mechanisms that sense and resolve DNA damage remain elusive. Studies have demonstrated that damage accumulated on lagging chromosomes can activate the spindle assembly checkpoint. However, there is little known regarding damage to DNA after anaphase onset. In this study, we demonstrate that laser-induced damage to chromosome tips (presumptive telomeres) in anaphase of Potorous tridactylis cells (PtK2) inhibits cytokinesis. In contrast, equivalent irradiation of non-telomeric chromosome regions or control irradiations in either the adjacent cytoplasm or adjacent to chromosome tips near the spindle midzone during anaphase caused no change in the eventual completion of cytokinesis. Damage to only one chromosome tip caused either complete absence of furrow formation, a prolonged delay in furrow formation, or furrow regression. When multiple chromosome tips were irradiated in the same cell, the cytokinesis defects increased, suggesting a potential dose-dependent mechanism. These results suggest a mechanism in which dysfunctional telomeres inhibit mitotic exit.
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Affiliation(s)
- Norman M. Baker
- Department of Electrical and Computer Engineering, University of California San Diego, La Jolla, California, United States of America
| | - Samantha G. Zeitlin
- Laboratory for Cell Biology, Ludwig Institute for Cancer Research, University of California San Diego, La Jolla, California, United States of America
| | - Linda Z. Shi
- Department of Bioengineering, University of California San Diego, La Jolla, California, United States of America
| | - Jagesh Shah
- Department of Systems Biology, Harvard Medical School and Renal Division, Brigham and Women's Hospital, Boston, Massachusetts, United States of America
- * E-mail: (MWB); (JS)
| | - Michael W. Berns
- Department of Bioengineering, University of California San Diego, La Jolla, California, United States of America
- Beckman Laser Institute, University of California Irvine, Irvine, California, United States of America
- * E-mail: (MWB); (JS)
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