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Jose SS, Tidu F, Burilova P, Kepak T, Bendickova K, Fric J. The Telomerase Complex Directly Controls Hematopoietic Stem Cell Differentiation and Senescence in an Induced Pluripotent Stem Cell Model of Telomeropathy. Front Genet 2018; 9:345. [PMID: 30210531 PMCID: PMC6123533 DOI: 10.3389/fgene.2018.00345] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Accepted: 08/09/2018] [Indexed: 01/16/2023] Open
Abstract
Telomeropathies are rare disorders associated with impaired telomere length control mechanisms that frequently result from genetic mutations in the telomerase complex. Dyskeratosis congenita is a congenital progressive telomeropathy in which mutation in the telomerase RNA component (TERC) impairs telomere maintenance leading to accelerated cellular senescence and clinical outcomes resembling premature aging. The most severe clinical feature is perturbed hematopoiesis and bone-marrow failure, but the underlying mechanisms are not fully understood. Here, we developed a model of telomerase function imbalance using shRNA to knockdown TERC expression in human induced pluripotent stem cells (iPSCs). We then promoted in vitro hematopoiesis in these cells to analyze the effects of TERC impairment. Reduced TERC expression impaired hematopoietic stem-cell (HSC) differentiation and increased the expression of cellular senescence markers and production of reactive oxygen species. Interestingly, telomere length was unaffected in shTERC knockdown iPSCs, leading to conclusion that the phenotype is controlled by non-telomeric functions of telomerase. We then assessed the effects of TERC-depletion in THP-1 myeloid cells and again observed reduced hematopoietic and myelopoietic differentiative potential. However, these cells exhibited impaired telomerase activity as verified by accelerated telomere shortening. shTERC-depleted iPSC-derived and THP-1-derived myeloid precursors had lower phagocytic capacity and increased ROS production, indicative of senescence. These findings were confirmed using a BIBR1532 TERT inhibitor, suggesting that these phenotypes are dependent on telomerase function but not directly linked to telomere length. These data provide a better understanding of the molecular processes driving the clinical signs of telomeropathies and identify novel roles of the telomerase complex other than regulating telomere length.
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Affiliation(s)
- Shyam Sushama Jose
- Cellular and Molecular Immunoregulation Group, Center for Translational Medicine, International Clinical Research Center, St. Anne's University Hospital Brno, Brno, Czechia.,Department of Biology, Faculty of Medicine, Masaryk University, Brno, Czechia
| | - Federico Tidu
- Cellular and Molecular Immunoregulation Group, Center for Translational Medicine, International Clinical Research Center, St. Anne's University Hospital Brno, Brno, Czechia.,Department of Biology, Faculty of Medicine, Masaryk University, Brno, Czechia
| | - Petra Burilova
- Cellular and Molecular Immunoregulation Group, Center for Translational Medicine, International Clinical Research Center, St. Anne's University Hospital Brno, Brno, Czechia.,Department of Biology, Faculty of Medicine, Masaryk University, Brno, Czechia
| | - Tomas Kepak
- Pediatric Oncology Translational Research, International Clinical Research Center, St. Anne's University Hospital Brno, Brno, Czechia.,Pediatric Hematology and Oncology, The University Hospital Brno, Brno, Czechia
| | - Kamila Bendickova
- Cellular and Molecular Immunoregulation Group, Center for Translational Medicine, International Clinical Research Center, St. Anne's University Hospital Brno, Brno, Czechia
| | - Jan Fric
- Cellular and Molecular Immunoregulation Group, Center for Translational Medicine, International Clinical Research Center, St. Anne's University Hospital Brno, Brno, Czechia
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Zhao B, Vo HQ, Johnston FH, Negishi K. Air pollution and telomere length: a systematic review of 12,058 subjects. Cardiovasc Diagn Ther 2018; 8:480-492. [PMID: 30214863 DOI: 10.21037/cdt.2018.06.05] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Background Over recent decades, adverse effects of ambient air pollution on the cardiovascular system have been clearly demonstrated. However, the underlying mechanisms are not fully elucidated. Air pollution may accelerates biological aging and thereby the susceptibility to cardiovascular diseases (CVDs). Telomeres are tandem repetitive DNA complexes that play a critical role in maintaining chromosome stability. There are, however, heterogeneities among the reported effects of air pollution on telomere. This study sought to evaluate the existing literature on the association between air pollution and telomere length (TL). Methods Two reviewers independently searched on electronic databases including PUBMED, EMBASE, SCOPUS, WEB OF SCIENCE and Ovid. The key terms were "air pollution" and "telomere" without language restriction. Articles relating to tobacco smoke were excluded. Results A total of 12,058 subjects from 25 articles remained for final review. All were observational studies: 14 cross-sectional, 6 cohort and 5 case-control studies. Nineteen (76%) assessed leukocyte telomere length (LTL) of which 15 found associations between air pollution and shorter TL, 2 with longer TL, 1 had mixed results, and a study of patients with type 2 diabetes found non-significant associations with TL. One found longer TL from saliva. The remaining studies were of placental cells, buccal cells or sperm and all reported shorter TL associated with air pollution. Particulate matter (PM) was investigated in 8 articles, and the remainder assessed black carbon (BC), benzene, lead, cadmium and polycyclic aromatic hydrocarbon (PAH). Geographically, 11 studies were conducted in Europe, with 10 in Asia and 4 in North America. While all followed Cawthon's protocol for TL assessment, discordance in the reporting formats did not allow us to perform a quantitative meta-analysis. Conclusions Most of the studies support the association of shorter TL with air pollution. Uniform reporting format would be warranted for future studies to estimate true effect size of air pollution on TL.
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Affiliation(s)
- Bing Zhao
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
| | - Ha Q Vo
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
| | - Fay H Johnston
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
| | - Kazuaki Negishi
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
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Mangaonkar AA, Ferrer A, Pinto E Vairo F, Cousin MA, Kuisle RJ, Klee EW, Kennedy CC, Peters SG, Scott JP, Utz JP, Baqir M, Sekiguchi H, Khan SP, Rodriguez V, Simonetto DA, Kamath PS, Abraham RS, Wylam ME, Patnaik MM. Clinical Correlates and Treatment Outcomes for Patients With Short Telomere Syndromes. Mayo Clin Proc 2018; 93:834-839. [PMID: 29976374 PMCID: PMC7646091 DOI: 10.1016/j.mayocp.2018.05.015] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Revised: 05/11/2018] [Accepted: 05/18/2018] [Indexed: 10/28/2022]
Abstract
Short telomere syndromes (STSs) are accelerated aging syndromes with multisystemic manifestations that present complex management challenges. In this article, we discuss a single-institution experience in diagnosing and managing patients with inherited STSs. In total, we identified 17 patients with short telomeres, defined by flow-fluorescence in-situ hybridization telomere lengths of less than first centile in granulocytes/lymphocytes OR the presence of a characteristic germline pathogenic variant in the context of a highly suggestive clinical phenotype. Genetic variations in the telomere complex were identified in 6 (35%) patients, with 4 being known pathogenic variants involving TERT (n=2), TERC (n=1), and DKC1 (n=1) genes, while 2 were variants of uncertain significance in TERT and RTEL1 genes. Idiopathic interstitial pneumonia (IIP) (n=12 [71%]), unexplained cytopenias (n=5 [29%]), and cirrhosis (n=2 [12%]) were most frequent clinical phenotypes at diagnosis. At median follow-up of 48 (range, 0-316) months, Kaplan-Meier estimate of overall survival, median (95% CI), was 182 (113, not reached) months. Treatment modalities included lung transplantation for IIP (n=5 [29%]), with 3 patients developing signs of acute cellular rejection (2, grade A2; 1, grade A1); danazol therapy for cytopenias (n=4 [24%]), with only 1 out of 4 patients showing a partial hematologic response; and allogeneic hematopoietic stem cell transplant for progressive bone marrow failure (n=2), with 1 patient dying from transplant-related complications. In summary, patients with STSs present with diverse clinical manifestations and require a multidisciplinary approach to management, with organ-specific transplantation capable of providing clinical benefit.
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Affiliation(s)
| | - Alejandro Ferrer
- Center for Individualized Medicine, Health Sciences Research, Mayo Clinic, Rochester, MN
| | - Filippo Pinto E Vairo
- Center for Individualized Medicine, Health Sciences Research, Mayo Clinic, Rochester, MN
| | - Margot A Cousin
- Center for Individualized Medicine, Health Sciences Research, Mayo Clinic, Rochester, MN
| | - Ryan J Kuisle
- Center for Individualized Medicine, Health Sciences Research, Mayo Clinic, Rochester, MN
| | - Eric W Klee
- Center for Individualized Medicine, Health Sciences Research, Mayo Clinic, Rochester, MN
| | - Cassie C Kennedy
- Division of Pulmonary and Critical Care Medicine, Mayo Clinic, Rochester, MN
| | - Steve G Peters
- Division of Pulmonary and Critical Care Medicine, Mayo Clinic, Rochester, MN
| | - J P Scott
- Division of Pulmonary and Critical Care Medicine, Mayo Clinic, Rochester, MN
| | - James P Utz
- Division of Pulmonary and Critical Care Medicine, Mayo Clinic, Rochester, MN
| | - Misbah Baqir
- Division of Pulmonary and Critical Care Medicine, Mayo Clinic, Rochester, MN
| | - Hiroshi Sekiguchi
- Division of Pulmonary and Critical Care Medicine, Mayo Clinic, Rochester, MN
| | - Shakila P Khan
- Division of Pediatric Hematology/Oncology, Mayo Clinic, Rochester, MN
| | | | | | | | - Roshini S Abraham
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN
| | - Mark E Wylam
- Division of Pulmonary and Critical Care Medicine, Mayo Clinic, Rochester, MN.
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Pańczyszyn A, Boniewska-Bernacka E. Telomeropathies: rare disease syndromes. MEDICAL SCIENCE PULSE 2018. [DOI: 10.5604/01.3001.0012.1165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Telomeres are located at the end of the chromosomes. They protect chromosomes from fusion and degradation. Every cell division causes a shortening of the telomeres. A special enzymatic complex called telomerase is responsible for maintaining telomere length in intensively dividing cells, such as epithelial cells and bone marrow cells. The enzymatic complex includes the TERT subunit, which has reverse transcriptase activity, and the TERC subunit, which acts as a template. Other important components of telomerase are the proteins that are responsible for structural stability. Telomerase remains active only in the dividing cells of the body. The rate of telomere shortening depends on many factors including age, sex, and comorbidities. Faster shortening of telomeres is caused by gene defects, which have an impact on telomerase action. Collectively, these are called telomeropathies. Common causes of telomeropathies are mutations in the TERT and TERC telomerase genes. Types of telemeropathies include dyskeratosis congenita, idiopathic pulmonary fibrosis, and aplastic anaemia, among others. Clinical manifestations and prognoses depend on the type and quantity of mutated genes. Diagnosis of telomeropathies is often problematic because they present with the same symptoms as other diseases. So far, no effective therapeutic methods have been developed for telomeropathies. A therapeutic method for patients with bone marrow failure may be the transplantation of hematopoietic stem cells. For patients with idiopathic pulmonary fibrosis, treatments include immunosuppressive therapy, lung transplantation, or palliative care. In the future, gene therapy may be an effective treatment strategy for telomeropathies. Lifestyle changes may also have a positive impact on the person. Physical activity combined with a healthy diet rich in antioxidants and unsaturated fatty acids can decrease the oxidative stress levels in cells and lead to a slower shortening of the telomeres.
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Affiliation(s)
- Anna Pańczyszyn
- Independent Department of Biotechnology and Molecular Biology, Faculty of Natural Sciences and Technology, University of Opole, Poland
| | - Ewa Boniewska-Bernacka
- Independent Department of Biotechnology and Molecular Biology, Faculty of Natural Sciences and Technology, University of Opole, Poland
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Li J, Chang J, Tian J, Ke J, Zhu Y, Yang Y, Gong Y, Zou D, Peng X, Yang N, Mei S, Wang X, Cheng L, Hu W, Gong J, Zhong R, Miao X. A Rare Variant P507L in TPP1 Interrupts TPP1-TIN2 Interaction, Influences Telomere Length, and Confers Colorectal Cancer Risk in Chinese Population. Cancer Epidemiol Biomarkers Prev 2018; 27:1029-1035. [PMID: 29891727 DOI: 10.1158/1055-9965.epi-18-0099] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2018] [Revised: 04/27/2018] [Accepted: 06/05/2018] [Indexed: 11/16/2022] Open
Abstract
Background: Telomere dysfunction triggers cellular senescence and constitutes a driving force for cancer initiation. Genetic variants in genes involved in telomere maintenance may contribute to colorectal cancer susceptibility.Methods: In this study, we firstly captured germline mutations in 192 patients with colorectal cancer by sequencing the coding regions of 13 core components implicated in telomere biology. Five potential functional variants were then genotyped and assessed in a case-control set with 3,761 colorectal cancer cases and 3,839 healthy controls. The promising association was replicated in additional 6,765 cases and 6,906 controls. Functional experiments were used to further clarify the potential function of the significant variant and uncover the underlying mechanism in colorectal cancer development.Results: The two-stage association studies showed that a rare missense variant rs149418249 (c.C1520T and p.P507L) in the 11th exon of TPP1 (also known as ACD, gene ID 65057) was significantly associated with colorectal cancer risk with the ORs being 2.90 [95% confidence interval (CI), 1.04-8.07; P = 0.041], 2.50 (95% CI, 1.04-6.04; P = 0.042), and 2.66 (95% CI, 1.36-5.18; P = 0.004) in discovery, replication, and the combined samples, respectively. Further functional annotation indicated that the TPP1 P507L substitution interrupted TPP1-TIN2 interaction, impaired telomerase processivity, and shortened telomere length, which subsequently facilitated cell proliferation and promoted colorectal cancer development.Conclusions: A rare variant P507L in TPP1 confers increased risk of colorectal cancer through interrupting TPP1-TIN2 interaction, impairing telomerase processivity, and shrinking telomere length.Impact: These findings emphasize the important role of telomere dysfunction in colorectal cancer development, and provide new insights about the prevention of this type of cancer. Cancer Epidemiol Biomarkers Prev; 27(9); 1029-35. ©2018 AACR.
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Affiliation(s)
- Jiaoyuan Li
- Department of Epidemiology and Biostatistics, and State Key Laboratory of Environment Health, MOE (Ministry of Education) Key Laboratory of Environment & Health, Ministry of Environmental Protection Key Laboratory of Environment and Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Jiang Chang
- Department of Epidemiology and Biostatistics, and State Key Laboratory of Environment Health, MOE (Ministry of Education) Key Laboratory of Environment & Health, Ministry of Environmental Protection Key Laboratory of Environment and Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Jianbo Tian
- Department of Epidemiology and Biostatistics, and State Key Laboratory of Environment Health, MOE (Ministry of Education) Key Laboratory of Environment & Health, Ministry of Environmental Protection Key Laboratory of Environment and Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Juntao Ke
- Department of Epidemiology and Biostatistics, and State Key Laboratory of Environment Health, MOE (Ministry of Education) Key Laboratory of Environment & Health, Ministry of Environmental Protection Key Laboratory of Environment and Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Ying Zhu
- Department of Epidemiology and Biostatistics, and State Key Laboratory of Environment Health, MOE (Ministry of Education) Key Laboratory of Environment & Health, Ministry of Environmental Protection Key Laboratory of Environment and Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yang Yang
- Department of Epidemiology and Biostatistics, and State Key Laboratory of Environment Health, MOE (Ministry of Education) Key Laboratory of Environment & Health, Ministry of Environmental Protection Key Laboratory of Environment and Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yajie Gong
- Department of Epidemiology and Biostatistics, and State Key Laboratory of Environment Health, MOE (Ministry of Education) Key Laboratory of Environment & Health, Ministry of Environmental Protection Key Laboratory of Environment and Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Danyi Zou
- Department of Epidemiology and Biostatistics, and State Key Laboratory of Environment Health, MOE (Ministry of Education) Key Laboratory of Environment & Health, Ministry of Environmental Protection Key Laboratory of Environment and Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xiating Peng
- Department of Epidemiology and Biostatistics, and State Key Laboratory of Environment Health, MOE (Ministry of Education) Key Laboratory of Environment & Health, Ministry of Environmental Protection Key Laboratory of Environment and Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Nan Yang
- Department of Epidemiology and Biostatistics, and State Key Laboratory of Environment Health, MOE (Ministry of Education) Key Laboratory of Environment & Health, Ministry of Environmental Protection Key Laboratory of Environment and Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Shufang Mei
- Department of Epidemiology and Biostatistics, and State Key Laboratory of Environment Health, MOE (Ministry of Education) Key Laboratory of Environment & Health, Ministry of Environmental Protection Key Laboratory of Environment and Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xiaoyang Wang
- Department of Epidemiology and Biostatistics, and State Key Laboratory of Environment Health, MOE (Ministry of Education) Key Laboratory of Environment & Health, Ministry of Environmental Protection Key Laboratory of Environment and Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Liming Cheng
- Department of Laboratory Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Weiguo Hu
- Department of Oncology, Renmin Hospital of Wuhan University, Wuhan, China
| | - Jing Gong
- Department of Epidemiology and Biostatistics, and State Key Laboratory of Environment Health, MOE (Ministry of Education) Key Laboratory of Environment & Health, Ministry of Environmental Protection Key Laboratory of Environment and Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Rong Zhong
- Department of Epidemiology and Biostatistics, and State Key Laboratory of Environment Health, MOE (Ministry of Education) Key Laboratory of Environment & Health, Ministry of Environmental Protection Key Laboratory of Environment and Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xiaoping Miao
- Department of Epidemiology and Biostatistics, and State Key Laboratory of Environment Health, MOE (Ministry of Education) Key Laboratory of Environment & Health, Ministry of Environmental Protection Key Laboratory of Environment and Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
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56
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Telomeres and aging. Curr Opin Cell Biol 2018; 52:1-7. [DOI: 10.1016/j.ceb.2017.12.001] [Citation(s) in RCA: 92] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Revised: 11/29/2017] [Accepted: 12/03/2017] [Indexed: 12/26/2022]
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Coburn SB, Graubard BI, Trabert B, McGlynn KA, Cook MB. Associations between circulating sex steroid hormones and leukocyte telomere length in men in the National Health and Nutrition Examination Survey. Andrology 2018; 6:542-546. [PMID: 29752772 DOI: 10.1111/andr.12494] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Revised: 02/07/2018] [Accepted: 03/22/2018] [Indexed: 01/27/2023]
Abstract
Preliminary evidence suggests that sex steroid hormones, such as danazol (a synthetic sex steroid hormone), may be involved in enhancing telomerase activity. Elucidating underlying mechanisms of telomerase activity may further therapeutic options for individuals with telomeropathies and potentially avert certain age-related conditions. Therefore, we conducted a cross-sectional study to investigate the relationship between circulating sex steroid hormones and SHBG with leukocyte telomere length among 499 males in NHANES (1999-2002 surveys). Sample-weighted linear regression analyses were conducted to assess age-adjusted and multivariable-adjusted estimates of associations. Estimates were rescaled to represent telomere length change in base pairs per half the value of the interquartile range of the independent variable. Estradiol and free estradiol were significantly inversely associated with leukocyte telomere length (βcontinuous per §IQR = -61, p = 0.04; free estradiol βcontinuous per §IQR = -67, p = 0.03). Testosterone, free testosterone, androstanediol glucuronide, and SHBG were not associated with leukocyte telomere length. The inverse association seen in this study indicates that a danazol-induced hypoestrogenic state could partly underlie the previously observed association between danazol therapy and increased leukocyte telomere length.
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Affiliation(s)
- S B Coburn
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, NIH, DHHS, Bethesda, MD, USA
| | - B I Graubard
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, NIH, DHHS, Bethesda, MD, USA
| | - B Trabert
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, NIH, DHHS, Bethesda, MD, USA
| | - K A McGlynn
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, NIH, DHHS, Bethesda, MD, USA
| | - M B Cook
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, NIH, DHHS, Bethesda, MD, USA
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58
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Gaspar TB, Sá A, Lopes JM, Sobrinho-Simões M, Soares P, Vinagre J. Telomere Maintenance Mechanisms in Cancer. Genes (Basel) 2018; 9:E241. [PMID: 29751586 PMCID: PMC5977181 DOI: 10.3390/genes9050241] [Citation(s) in RCA: 77] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Revised: 04/20/2018] [Accepted: 04/23/2018] [Indexed: 12/12/2022] Open
Abstract
Tumour cells can adopt telomere maintenance mechanisms (TMMs) to avoid telomere shortening, an inevitable process due to successive cell divisions. In most tumour cells, telomere length (TL) is maintained by reactivation of telomerase, while a small part acquires immortality through the telomerase-independent alternative lengthening of telomeres (ALT) mechanism. In the last years, a great amount of data was generated, and different TMMs were reported and explained in detail, benefiting from genome-scale studies of major importance. In this review, we address seven different TMMs in tumour cells: mutations of the TERT promoter (TERTp), amplification of the genes TERT and TERC, polymorphic variants of the TERT gene and of its promoter, rearrangements of the TERT gene, epigenetic changes, ALT, and non-defined TMM (NDTMM). We gathered information from over fifty thousand patients reported in 288 papers in the last years. This wide data collection enabled us to portray, by organ/system and histotypes, the prevalence of TERTp mutations, TERT and TERC amplifications, and ALT in human tumours. Based on this information, we discuss the putative future clinical impact of the aforementioned mechanisms on the malignant transformation process in different setups, and provide insights for screening, prognosis, and patient management stratification.
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Affiliation(s)
- Tiago Bordeira Gaspar
- Cancer Signaling and Metabolism Group, Institute for Research and Innovation in Health Sciences (i3S), University of Porto, 4200-135 Porto, Portugal.
- Cancer Signaling and Metabolism Group, Institute of Molecular Pathology and Immunology of the University of Porto (Ipatimup), 4200-135 Porto, Portugal.
- Medical Faculty of University of Porto (FMUP), 4200-139 Porto, Portugal.
- Abel Salazar Biomedical Sciences Institute (ICBAS), University of Porto, 4050-313 Porto, Portugal.
| | - Ana Sá
- Cancer Signaling and Metabolism Group, Institute for Research and Innovation in Health Sciences (i3S), University of Porto, 4200-135 Porto, Portugal.
- Cancer Signaling and Metabolism Group, Institute of Molecular Pathology and Immunology of the University of Porto (Ipatimup), 4200-135 Porto, Portugal.
- Abel Salazar Biomedical Sciences Institute (ICBAS), University of Porto, 4050-313 Porto, Portugal.
| | - José Manuel Lopes
- Cancer Signaling and Metabolism Group, Institute for Research and Innovation in Health Sciences (i3S), University of Porto, 4200-135 Porto, Portugal.
- Cancer Signaling and Metabolism Group, Institute of Molecular Pathology and Immunology of the University of Porto (Ipatimup), 4200-135 Porto, Portugal.
- Medical Faculty of University of Porto (FMUP), 4200-139 Porto, Portugal.
- Department of Pathology and Oncology, Centro Hospitalar São João, 4200-139 Porto, Portugal.
| | - Manuel Sobrinho-Simões
- Cancer Signaling and Metabolism Group, Institute for Research and Innovation in Health Sciences (i3S), University of Porto, 4200-135 Porto, Portugal.
- Cancer Signaling and Metabolism Group, Institute of Molecular Pathology and Immunology of the University of Porto (Ipatimup), 4200-135 Porto, Portugal.
- Medical Faculty of University of Porto (FMUP), 4200-139 Porto, Portugal.
- Department of Pathology and Oncology, Centro Hospitalar São João, 4200-139 Porto, Portugal.
| | - Paula Soares
- Cancer Signaling and Metabolism Group, Institute for Research and Innovation in Health Sciences (i3S), University of Porto, 4200-135 Porto, Portugal.
- Cancer Signaling and Metabolism Group, Institute of Molecular Pathology and Immunology of the University of Porto (Ipatimup), 4200-135 Porto, Portugal.
- Abel Salazar Biomedical Sciences Institute (ICBAS), University of Porto, 4050-313 Porto, Portugal.
| | - João Vinagre
- Cancer Signaling and Metabolism Group, Institute for Research and Innovation in Health Sciences (i3S), University of Porto, 4200-135 Porto, Portugal.
- Cancer Signaling and Metabolism Group, Institute of Molecular Pathology and Immunology of the University of Porto (Ipatimup), 4200-135 Porto, Portugal.
- Medical Faculty of University of Porto (FMUP), 4200-139 Porto, Portugal.
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Nguyen THD, Tam J, Wu RA, Greber BJ, Toso D, Nogales E, Collins K. Cryo-EM structure of substrate-bound human telomerase holoenzyme. Nature 2018; 557:190-195. [PMID: 29695869 PMCID: PMC6223129 DOI: 10.1038/s41586-018-0062-x] [Citation(s) in RCA: 146] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Accepted: 03/28/2018] [Indexed: 11/29/2022]
Abstract
Telomerase adds telomeric repeats to chromosome ends to balance incomplete replication. Telomerase regulation is implicated in cancer, aging and other human diseases, but progress towards telomerase clinical manipulation is hampered by the lack of structural data. Here we present the cryo-electron microscopy structure of substrate-bound human telomerase holoenzyme at subnanometer resolution, describing two flexibly RNA-tethered lobes: the catalytic core with telomerase reverse transcriptase (TERT) and conserved motifs of telomerase RNA (hTR), and an H/ACA ribonucleoprotein (RNP). In the catalytic core, RNA encircles TERT, adopting a well-ordered tertiary structure with surprisingly limited protein-RNA interactions. The H/ACA RNP lobe comprises two sets of heterotetrameric H/ACA proteins and one Cajal body protein, TCAB1, representing a pioneering structure of a large eukaryotic family of ribosome and spliceosome biogenesis factors. Our findings provide a structural framework for understanding human telomerase disease mutations and represent an important step towards telomerase-related clinical therapeutics.
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Affiliation(s)
- Thi Hoang Duong Nguyen
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA.,California Institute for Quantitative Biology, University of California, Berkeley, CA, USA.,Molecular Biophysics and Integrative Bio-Imaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.,Miller Institute for Basic Research in Science, University of California, Berkeley, CA, USA
| | - Jane Tam
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA
| | - Robert A Wu
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA.,Harvard Medical School, Boston, MA, USA
| | - Basil J Greber
- California Institute for Quantitative Biology, University of California, Berkeley, CA, USA.,Molecular Biophysics and Integrative Bio-Imaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Daniel Toso
- California Institute for Quantitative Biology, University of California, Berkeley, CA, USA
| | - Eva Nogales
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA. .,California Institute for Quantitative Biology, University of California, Berkeley, CA, USA. .,Molecular Biophysics and Integrative Bio-Imaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA. .,Howard Hughes Medical Institute, University of California, Berkeley, CA, USA.
| | - Kathleen Collins
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA. .,California Institute for Quantitative Biology, University of California, Berkeley, CA, USA.
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Lidzbarsky G, Gutman D, Shekhidem HA, Sharvit L, Atzmon G. Genomic Instabilities, Cellular Senescence, and Aging: In Vitro, In Vivo and Aging-Like Human Syndromes. Front Med (Lausanne) 2018; 5:104. [PMID: 29719834 PMCID: PMC5913290 DOI: 10.3389/fmed.2018.00104] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2018] [Accepted: 03/29/2018] [Indexed: 12/20/2022] Open
Abstract
As average life span and elderly people prevalence in the western world population is gradually increasing, the incidence of age-related diseases such as cancer, heart diseases, diabetes, and dementia is increasing, bearing social and economic consequences worldwide. Understanding the molecular basis of aging-related processes can help extend the organism’s health span, i.e., the life period in which the organism is free of chronic diseases or decrease in basic body functions. During the last few decades, immense progress was made in the understanding of major components of aging and healthy aging biology, including genomic instability, telomere attrition, epigenetic changes, proteostasis, nutrient sensing, mitochondrial dysfunction, cellular senescence, stem cell exhaustion, and intracellular communications. This progress has been made by three spear-headed strategies: in vitro (cell and tissue culture from various sources), in vivo (includes diverse model and non-model organisms), both can be manipulated and translated to human biology, and the study of aging-like human syndromes and human populations. Herein, we will focus on current repository of genomic “senescence” stage of aging, which includes health decline, structural changes of the genome, faulty DNA damage response and DNA damage, telomere shortening, and epigenetic alterations. Although aging is a complex process, many of the “hallmarks” of aging are directly related to DNA structure and function. This review will illustrate the variety of these studies, done in in vitro, in vivo and human levels, and highlight the unique potential and contribution of each research level and eventually the link between them.
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Affiliation(s)
| | - Danielle Gutman
- Department of Human Biology, University of Haifa, Haifa, Israel
| | | | - Lital Sharvit
- Department of Human Biology, University of Haifa, Haifa, Israel
| | - Gil Atzmon
- Department of Human Biology, University of Haifa, Haifa, Israel
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61
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Tanaka H, Phipps EA, Wei T, Wu X, Goswami C, Liu Y, Sledge GW, Mina L, Herbert BS. Altered expression of telomere-associated genes in leukocytes among BRCA1 and BRCA2 carriers. Mol Carcinog 2018; 57:567-575. [PMID: 29240257 PMCID: PMC5832588 DOI: 10.1002/mc.22773] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Revised: 11/29/2017] [Accepted: 12/07/2017] [Indexed: 12/31/2022]
Abstract
Telomere dysfunction resulting from telomere shortening and deregulation of shelterin components has been linked to the pathogenesis of age-related disorders, including cancer. Recent evidence suggests that BRCA1/2 (BRCA1 and BRCA2) tumor suppressor gene products play an important role in telomere maintenance. Although telomere shortening has been reported in BRCA1/2 carriers, the direct effects of BRCA1/2 haploinsufficiency on telomere maintenance and predisposition to cancer development are not completely understood. In this study, we assessed the telomere-associated and telomere-proximal gene expression profiles in peripheral blood leukocytes from patients with a BRCA1 or BRCA2 mutation, compared to samples from sporadic and familial breast cancer individuals. We found that 25 genes, including TINF2 gene (a negative regulator of telomere length), were significantly differentially expressed in BRCA1 carriers. Leukocyte telomere length analysis revealed that BRCA1/2 carriers had relatively shorter telomeres than healthy controls. Further, affected BRCA1/2 carriers were well differentiated from unaffected BRCA1/2 carriers by the expression of telomere-proximal genes. Our results link BRCA1/2 haploinsufficiency to changes in telomere length, telomere-associated as well as telomere-proximal gene expression. Thus, this work supports the effect of BRCA1/2 haploinsufficiency in the biology underlying telomere dysfunction in cancer development. Future studies evaluating these findings will require a large study population.
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Affiliation(s)
- Hiromi Tanaka
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN
- Indiana University Melvin and Bren Simon Cancer Center, Indianapolis, IN
| | - Elizabeth A. Phipps
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN
| | - Ting Wei
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN
| | - Xi Wu
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN
| | - Chirayu Goswami
- Center for Computational Biology and Bioinformatics, Indiana University School of Medicine, Indianapolis, IN
| | - Yunlong Liu
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN
- Indiana University Melvin and Bren Simon Cancer Center, Indianapolis, IN
- Center for Computational Biology and Bioinformatics, Indiana University School of Medicine, Indianapolis, IN
- Center for Medical Genomics, Indiana University School of Medicine, Indianapolis, IN
| | | | - Lida Mina
- Department of Medicine, Indiana University School of Medicine, Indianapolis, IN
| | - Brittney-Shea Herbert
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN
- Indiana University Melvin and Bren Simon Cancer Center, Indianapolis, IN
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62
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Guerra L, Castori M, Didona B, Castiglia D, Zambruno G. Hereditary palmoplantar keratodermas. Part II: syndromic palmoplantar keratodermas - Diagnostic algorithm and principles of therapy. J Eur Acad Dermatol Venereol 2018; 32:899-925. [DOI: 10.1111/jdv.14834] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Accepted: 01/05/2018] [Indexed: 12/19/2022]
Affiliation(s)
- L. Guerra
- Laboratory of Molecular and Cell Biology; Istituto Dermopatico dell'Immacolata-IRCCS; Rome Italy
| | - M. Castori
- Division of Medical Genetics; Casa Sollievo della Sofferenza-IRCCS; San Giovanni Rotondo Italy
| | - B. Didona
- Rare Skin Disease Center; Istituto Dermopatico dell'Immacolata-IRCCS; Rome Italy
| | - D. Castiglia
- Laboratory of Molecular and Cell Biology; Istituto Dermopatico dell'Immacolata-IRCCS; Rome Italy
| | - G. Zambruno
- Genetic and Rare Diseases Research Area and Dermatology Unit; Bambino Gesù Children's Hospital-IRCCS; Rome Italy
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63
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Stewart JA, Wang Y, Ackerson SM, Schuck PL. Emerging roles of CST in maintaining genome stability and human disease. Front Biosci (Landmark Ed) 2018; 23:1564-1586. [PMID: 29293451 DOI: 10.2741/4661] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The human CTC1-STN1-TEN1 (CST) complex is a single-stranded DNA binding protein that shares homology with RPA and interacts with DNA polymerase alpha/primase. CST complexes are conserved from yeasts to humans and function in telomere maintenance. A common role of CST across species is in the regulation of telomere extension by telomerase and C-strand fill-in synthesis. However, recent studies also indicate that CST promotes telomere duplex replication as well the rescue of stalled DNA replication at non-telomeric sites. Furthermore, CST dysfunction and mutation is associated with several genetic diseases and cancers. In this review, we will summarize what is known about CST with a particular focus on the emerging roles of CST in DNA replication and human disease.
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Affiliation(s)
- Jason A Stewart
- Department of Biological Sciences, University of South Carolina, Columbia, SC 29208, USA,
| | - Yilin Wang
- Department of Biological Sciences, University of South Carolina, Columbia, SC 29208, USA
| | - Stephanie M Ackerson
- Department of Biological Sciences, University of South Carolina, Columbia, SC 29208, USA
| | - Percy Logan Schuck
- Department of Biological Sciences, University of South Carolina, Columbia, SC 29208, USA
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Novel variants in Nordic patients referred for genetic testing of telomere-related disorders. Eur J Hum Genet 2018; 26:858-867. [PMID: 29483670 DOI: 10.1038/s41431-018-0112-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Revised: 11/24/2017] [Accepted: 01/23/2018] [Indexed: 01/27/2023] Open
Abstract
Telomere-related disorders are a clinically and genetically heterogeneous group of disorders characterized by premature telomere shortening and proliferative failure of a variety of tissues. This study reports the spectrum of telomere-related gene variants and telomere length in Nordic patients referred for genetic testing due to suspected telomere-related disorder. We performed Sanger sequencing of the genes TERT, TERC, DKC1, and TINF2 on 135 unrelated index patients and measured telomere length by qPCR on DNA from peripheral blood leukocytes. We identified pathogenic or likely pathogenic variants in 10 index patients, all of which had short telomeres compared to age-matched healthy controls. Six of the 10 variants were novel; three in TERC (n.69_74dupAGGCGC, n.122_125delGCGG, and n.407_408delinsAA) and three in TERT (p.(D684G), p.(R774*), and p.(*1133Wext*39)). The high proportion of novel variants identified in our study highlights the need for solid interpretation of new variants that may be detected. Measurement of telomere length is a useful approach for evaluating pathogenicity of genetic variants associated with telomere-related disorders.
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65
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Povedano JM, Martinez P, Serrano R, Tejera Á, Gómez-López G, Bobadilla M, Flores JM, Bosch F, Blasco MA. Therapeutic effects of telomerase in mice with pulmonary fibrosis induced by damage to the lungs and short telomeres. eLife 2018; 7:31299. [PMID: 29378675 PMCID: PMC5818250 DOI: 10.7554/elife.31299] [Citation(s) in RCA: 74] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Accepted: 01/23/2018] [Indexed: 12/31/2022] Open
Abstract
Pulmonary fibrosis is a fatal lung disease characterized by fibrotic foci and inflammatory infiltrates. Short telomeres can impair tissue regeneration and are found both in hereditary and sporadic cases. We show here that telomerase expression using AAV9 vectors shows therapeutic effects in a mouse model of pulmonary fibrosis owing to a low-dose bleomycin insult and short telomeres. AAV9 preferentially targets regenerative alveolar type II cells (ATII). AAV9-Tert-treated mice show improved lung function and lower inflammation and fibrosis at 1–3 weeks after viral treatment, and improvement or disappearance of the fibrosis at 8 weeks after treatment. AAV9-Tert treatment leads to longer telomeres and increased proliferation of ATII cells, as well as lower DNA damage, apoptosis, and senescence. Transcriptome analysis of ATII cells confirms downregulation of fibrosis and inflammation pathways. We provide a proof-of-principle that telomerase activation may represent an effective treatment for pulmonary fibrosis provoked or associated with short telomeres. Idiopathic pulmonary fibrosis (or IPF for short) is a rare disease that scars the lungs. The condition gets worse over time, making it harder and harder to breathe, and eventually leading to death. Patients typically only survive for a few years after being diagnosed with IPF. This is because, as yet, there is no cure; the available treatments only act to lessen the symptoms. Several risk factors have linked to the development of IPF, among them, the presence of short telomeres. Like the plastic tips on shoelaces, telomeres are protective structures at the ends of chromosomes. Telomeres shorten with age, and when they become too short the cell stops dividing and often dies in a process known as apoptosis. IPF can develop when the telomeres in the cells that repair everyday wear and tear in the lungs (known as ATII cells) become too short. This means that the damage goes unrepaired, triggering an immune reaction and uncontrolled scarring. Telomerase is an enzyme that can lengthen short telomeres, and Povedano, Martínez et al. set out to develop a new treatment approach that would use this enzyme to correct the short telomeres, and cure the scarring seen in IPF. Gene therapy was used to introduce the gene for telomerase into mice that had scarring in their lungs due to short telomeres. Povedano, Martínez et al. found that, when injected into the mice, the telomerase gene therapy was able to reach ATII cells and could help to heal the lungs. At the level of individual cells, mice treated with telomerase had longer telomeres, meaning that more of their ATII cells stayed alive and kept dividing to regenerate the lung tissue. Consistent with previous studies, the telomerase gene therapy caused no negative side effects in the mice; for example, there was no increased risk of cancer. These findings may possibly lead to new treatments for those patients suffering from IPF associated with short telomeres. Developing this approach into a clinical trial could in the future benefit many IPF patients who currently have very limited treatment options.
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Affiliation(s)
- Juan Manuel Povedano
- Telomeres and Telomerase Group, Molecular Oncology Program, Spanish National Cancer Centre, Madrid, Spain
| | - Paula Martinez
- Telomeres and Telomerase Group, Molecular Oncology Program, Spanish National Cancer Centre, Madrid, Spain
| | - Rosa Serrano
- Telomeres and Telomerase Group, Molecular Oncology Program, Spanish National Cancer Centre, Madrid, Spain
| | - Águeda Tejera
- Telomeres and Telomerase Group, Molecular Oncology Program, Spanish National Cancer Centre, Madrid, Spain
| | - Gonzalo Gómez-López
- Bioinformatics Core Unit, Structural Biology and Biocomputing Program, Spanish National Cancer Centre, Madrid, Spain
| | - Maria Bobadilla
- Roche Pharma Research and Early Development (pRED), Neuroscience, Ophthalmology and Rare Disease, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, Basel, Switzerland.,Roche Partnering, EIN, F. Hoffmann-La Roche Ltd, Basel, Switzerland
| | - Juana Maria Flores
- Animal Surgery and Medicine Department, Faculty of Veterinary Science, Complutense University of Madrid, Madrid, Spain
| | - Fátima Bosch
- Centre of Animal Biotechnology and Gene Therapy, Department of Biochemistry and Molecular Biology, School of Veterinary Medicine, Autonomous University of Barcelona, Bellaterra, Spain
| | - Maria A Blasco
- Telomeres and Telomerase Group, Molecular Oncology Program, Spanish National Cancer Centre, Madrid, Spain
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66
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Yan T, Ooi WF, Qamra A, Cheung A, Ma D, Sundaram GM, Xu C, Xing M, Poon L, Wang J, Loh YP, Ho JHJ, Ng JJQ, Ramlee MK, Aswad L, Rozen SG, Ghosh S, Bard FA, Sampath P, Tergaonkar V, Davies JOJ, Hughes JR, Goh E, Bi X, Fullwood MJ, Tan P, Li S. HoxC5 and miR-615-3p target newly evolved genomic regions to repress hTERT and inhibit tumorigenesis. Nat Commun 2018; 9:100. [PMID: 29311615 PMCID: PMC5758779 DOI: 10.1038/s41467-017-02601-1] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Accepted: 12/13/2017] [Indexed: 02/06/2023] Open
Abstract
The repression of telomerase activity during cellular differentiation promotes replicative aging and functions as a physiological barrier for tumorigenesis in long-lived mammals, including humans. However, the underlying mechanisms remain largely unclear. Here we describe how miR-615-3p represses hTERT expression. mir-615-3p is located in an intron of the HOXC5 gene, a member of the highly conserved homeobox family of transcription factors controlling embryogenesis and development. Unexpectedly, we found that HoxC5 also represses hTERT expression by disrupting the long-range interaction between hTERT promoter and its distal enhancer. The 3'UTR of hTERT and its upstream enhancer region are well conserved in long-lived primates. Both mir-615-3p and HOXC5 are activated upon differentiation, which constitute a feed-forward loop that coordinates transcriptional and post-transcriptional repression of hTERT during cellular differentiation. Deregulation of HOXC5 and mir-615-3p expression may contribute to the activation of hTERT in human cancers.
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Affiliation(s)
- TingDong Yan
- Cancer and Stem Cell Biology Program, Duke-NUS Medical School, 8 College Road, Singapore, 169857, Singapore
| | - Wen Fong Ooi
- Cancer Therapeutics and Stratified Oncology, Genome Institute of Singapore, 60 Biopolis Street, Singapore, 138672, Singapore
| | - Aditi Qamra
- Cancer Therapeutics and Stratified Oncology, Genome Institute of Singapore, 60 Biopolis Street, Singapore, 138672, Singapore
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, 2 Medical Drive, Singapore, 117597, Singapore
| | - Alice Cheung
- Cancer and Stem Cell Biology Program, Duke-NUS Medical School, 8 College Road, Singapore, 169857, Singapore
| | - DongLiang Ma
- Neuroscience Academic Clinical Programme, Duke-NUS Medical School, 8 College Road, Singapore, 169857, Singapore
- Department of Research, National Neuroscience Institute, 11 Jalan Tan Tock Seng, Singapore, 308433, Singapore
| | | | - Chang Xu
- Cancer and Stem Cell Biology Program, Duke-NUS Medical School, 8 College Road, Singapore, 169857, Singapore
- Cancer Science Institute of Singapore, National University of Singapore, 14 Medical Drive, Singapore, 117599, Singapore
| | - Manjie Xing
- Cancer and Stem Cell Biology Program, Duke-NUS Medical School, 8 College Road, Singapore, 169857, Singapore
- Cancer Therapeutics and Stratified Oncology, Genome Institute of Singapore, 60 Biopolis Street, Singapore, 138672, Singapore
| | - LaiFong Poon
- Cancer and Stem Cell Biology Program, Duke-NUS Medical School, 8 College Road, Singapore, 169857, Singapore
| | - Jing Wang
- Cancer and Stem Cell Biology Program, Duke-NUS Medical School, 8 College Road, Singapore, 169857, Singapore
| | - Yan Ping Loh
- Cancer Science Institute of Singapore, National University of Singapore, 14 Medical Drive, Singapore, 117599, Singapore
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore, 637551, Singapore
| | - Jess Hui Jie Ho
- Cancer and Stem Cell Biology Program, Duke-NUS Medical School, 8 College Road, Singapore, 169857, Singapore
| | - Joscelyn Jun Quan Ng
- Cancer and Stem Cell Biology Program, Duke-NUS Medical School, 8 College Road, Singapore, 169857, Singapore
| | - Muhammad Khairul Ramlee
- Cancer and Stem Cell Biology Program, Duke-NUS Medical School, 8 College Road, Singapore, 169857, Singapore
| | - Luay Aswad
- Cancer Science Institute of Singapore, National University of Singapore, 14 Medical Drive, Singapore, 117599, Singapore
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore, 637551, Singapore
| | - Steve G Rozen
- Cancer and Stem Cell Biology Program, Duke-NUS Medical School, 8 College Road, Singapore, 169857, Singapore
- Duke-NUS Centre for Computational Biology, Duke-NUS Medical School, 8 College Road, Singapore, 169857, Singapore
| | - Sujoy Ghosh
- Cardiovascular and Metabolic Disorders Program, Duke-NUS Medical School, 8 College Road, Singapore, 169857, Singapore
| | - Frederic A Bard
- Institute of Molecular and Cell Biology (IMCB), Singapore, 138673, Singapore
| | - Prabha Sampath
- Cancer and Stem Cell Biology Program, Duke-NUS Medical School, 8 College Road, Singapore, 169857, Singapore
- Institute of Medical Biology (IMB), 8A Biomedical Grove, Singapore, 138648, Singapore
| | - Vinay Tergaonkar
- Institute of Molecular and Cell Biology (IMCB), Singapore, 138673, Singapore
| | - James O J Davies
- Medical Research Council (MRC) Molecular Haematology Unit, Weatherall Institute of Molecular Medicine, Oxford University, Oxford, OX3 9DS, UK
| | - Jim R Hughes
- Medical Research Council (MRC) Molecular Haematology Unit, Weatherall Institute of Molecular Medicine, Oxford University, Oxford, OX3 9DS, UK
| | - Eyleen Goh
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, 2 Medical Drive, Singapore, 117597, Singapore
- Neuroscience Academic Clinical Programme, Duke-NUS Medical School, 8 College Road, Singapore, 169857, Singapore
- Department of Research, National Neuroscience Institute, 11 Jalan Tan Tock Seng, Singapore, 308433, Singapore
| | - Xuezhi Bi
- Bioprocessing Technology Institute, 20 Biopolis Street, Singapore, 138669, Singapore
| | - Melissa Jane Fullwood
- Cancer Science Institute of Singapore, National University of Singapore, 14 Medical Drive, Singapore, 117599, Singapore
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore, 637551, Singapore
- Institute of Molecular and Cell Biology (IMCB), Singapore, 138673, Singapore
| | - Patrick Tan
- Cancer and Stem Cell Biology Program, Duke-NUS Medical School, 8 College Road, Singapore, 169857, Singapore
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, 2 Medical Drive, Singapore, 117597, Singapore
- Cancer Science Institute of Singapore, National University of Singapore, 14 Medical Drive, Singapore, 117599, Singapore
- Duke-NUS Centre for Computational Biology, Duke-NUS Medical School, 8 College Road, Singapore, 169857, Singapore
- Cellular and Molecular Research, National Cancer Centre, 11 Hospital Drive, Singapore, 169610, Singapore
| | - Shang Li
- Cancer and Stem Cell Biology Program, Duke-NUS Medical School, 8 College Road, Singapore, 169857, Singapore.
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, 2 Medical Drive, Singapore, 117597, Singapore.
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67
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Fiorini E, Santoni A, Colla S. Dysfunctional telomeres and hematological disorders. Differentiation 2018; 100:1-11. [PMID: 29331736 DOI: 10.1016/j.diff.2018.01.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Revised: 12/21/2017] [Accepted: 01/02/2018] [Indexed: 12/25/2022]
Abstract
Telomere biology disorders, which are characterized by telomerase activity haploinsufficiency and accelerated telomere shortening, most commonly manifest as degenerative diseases. Tissues with high rates of cell turnover, such as those in the hematopoietic system, are particularly vulnerable to defects in telomere maintenance genes that eventually culminate in bone marrow (BM) failure syndromes, in which the BM cannot produce sufficient new blood cells. Here, we review how telomere defects induce degenerative phenotypes across multiple organs, with particular focus on how they impact the hematopoietic stem and progenitor compartment and affect hematopoietic stem cell (HSC) self-renewal and differentiation. We also discuss how both the increased risk of myelodysplastic syndromes and other hematological malignancies that is associated with telomere disorders and the discovery of cancer-associated somatic mutations in the shelterin components challenge the conventional interpretation that telomere defects are cancer-protective rather than cancer-promoting.
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Affiliation(s)
- Elena Fiorini
- Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Andrea Santoni
- Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Simona Colla
- Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA.
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68
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Kim W, Shay JW. Long-range telomere regulation of gene expression: Telomere looping and telomere position effect over long distances (TPE-OLD). Differentiation 2018; 99:1-9. [PMID: 29197683 PMCID: PMC5826875 DOI: 10.1016/j.diff.2017.11.005] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Revised: 11/11/2017] [Accepted: 11/21/2017] [Indexed: 01/09/2023]
Abstract
The human cellular reverse transcriptase, telomerase, is very tightly regulated in large long-lived species. Telomerase is expressed during early human fetal development, is turned off in most adult tissues, and then becomes reactivated in almost all human cancers. However, the exact mechanism regulating these switches in expression are not known. We recently described a phenomenon where genes are regulated by telomere length dependent loops (telomere position effects over long distances; TPE-OLD). The hTERT gene is ~ 1.2Mb from the human chromosome 5p end. We observed that when telomeres are long hTERT gene expression is repressed and a probe next to the 5p telomere and the hTERT locus are spatially co-localized. When telomeres are short at least one of the hTERT alleles is spatially separated from the telomere, developing more active histone marks and changes in DNA methylation in the hTERT promoter region. These findings have implications for how cells turn off telomerase when telomeres are long during fetal development and how cancer cells reactivate telomerase in cells that have short telomeres. In addition to TPE-OLD, in proliferating stem cells such as activated T-lymphocytes, telomerase can be reversibly activated and silenced by telomere looping. In telomerase positive cancer cells that are induced to differentiate and downregulate telomerase, telomere looping correlates with silencing of the hTERT gene. These studies and others support a role of telomeres in regulating gene expression via telomere looping that may involve interactions with internal telomeric sequences (ITS). In addition to telomere looping, TPE-OLD may be one mechanism of how cells time changes in physiology without initiating a DNA damage response.
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Affiliation(s)
- Wanil Kim
- Department of Cell Biology, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390, USA
| | - Jerry W Shay
- Department of Cell Biology, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390, USA.
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69
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Abstract
Schmutz and de Lange discuss the shelterin complex, which binds to mammalian telomeres and allows for the natural ends of chromosomes to be distinguished from sites of DNA damage.
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Affiliation(s)
- Isabelle Schmutz
- Laboratory for Cell Biology and Genetics, Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Titia de Lange
- Laboratory for Cell Biology and Genetics, Rockefeller University, 1230 York Avenue, New York, NY 10065, USA.
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70
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Carneiro MC, de Castro IP, Ferreira MG. Telomeres in aging and disease: lessons from zebrafish. Dis Model Mech 2017; 9:737-48. [PMID: 27482813 PMCID: PMC4958310 DOI: 10.1242/dmm.025130] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Age is the highest risk factor for some of the most prevalent human diseases, including cancer. Telomere shortening is thought to play a central role in the aging process in humans. The link between telomeres and aging is highlighted by the fact that genetic diseases causing telomerase deficiency are associated with premature aging and increased risk of cancer. For the last two decades, this link has been mostly investigated using mice that have long telomeres. However, zebrafish has recently emerged as a powerful and complementary model system to study telomere biology. Zebrafish possess human-like short telomeres that progressively decline with age, reaching lengths in old age that are observed when telomerase is mutated. The extensive characterization of its well-conserved molecular and cellular physiology makes this vertebrate an excellent model to unravel the underlying relationship between telomere shortening, tissue regeneration, aging and disease. In this Review, we explore the advantages of using zebrafish in telomere research and discuss the primary discoveries made in this model that have contributed to expanding our knowledge of how telomere attrition contributes to cellular senescence, organ dysfunction and disease. Summary: In this Review, the authors explore the advantages of using zebrafish in telomere research and discuss the primary discoveries made in this model that have contributed to expanding our knowledge of how telomere attrition contributes to cellular senescence, organ dysfunction and disease.
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71
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Gruszka AM, Valli D, Alcalay M. Understanding the molecular basis of acute myeloid leukemias: where are we now? Int J Hematol Oncol 2017; 6:43-53. [PMID: 30302223 DOI: 10.2217/ijh-2017-0002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Accepted: 03/29/2017] [Indexed: 12/26/2022] Open
Abstract
Although the treatment modalities for acute myeloid leukemia (AML) have not changed much over the past 40 years, distinct progress has been made in deciphering the basic biology underlying the pathogenesis of this group of hematological disorders. Studies show that AML development is a multicause, multistep and multipathway process. Accordingly, AMLs constitute a heterogeneous group of diseases. The thorough understanding of the molecular basis of AML is paving the way for better therapeutic approaches. Multiple novel drugs are being introduced and new, more efficient and less toxic formulations of conventional therapeutics are becoming available. Here, we review the recent advances in the comprehension of the molecular processes that lead to the onset of AML and its translation into clinical practice.
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Affiliation(s)
- Alicja M Gruszka
- Department of Experimental Oncology, Istituto Europeo di Oncologia, Via Adamello 16, 20139 Milano, Italy.,Department of Experimental Oncology, Istituto Europeo di Oncologia, Via Adamello 16, 20139 Milano, Italy
| | - Debora Valli
- Department of Experimental Oncology, Istituto Europeo di Oncologia, Via Adamello 16, 20139 Milano, Italy.,Department of Experimental Oncology, Istituto Europeo di Oncologia, Via Adamello 16, 20139 Milano, Italy
| | - Myriam Alcalay
- Department of Experimental Oncology, Istituto Europeo di Oncologia, Via Adamello 16, 20139 Milano, Italy.,Department of Oncology & Hemato-Oncology, University of Milan, Via Festa del Perdono 7, 20122 Milano, Italy.,Department of Experimental Oncology, Istituto Europeo di Oncologia, Via Adamello 16, 20139 Milano, Italy.,Department of Oncology & Hemato-Oncology, University of Milan, Via Festa del Perdono 7, 20122 Milano, Italy
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Cell cycle arrest through indirect transcriptional repression by p53: I have a DREAM. Cell Death Differ 2017; 25:114-132. [PMID: 29125603 PMCID: PMC5729532 DOI: 10.1038/cdd.2017.172] [Citation(s) in RCA: 411] [Impact Index Per Article: 58.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Revised: 09/10/2017] [Accepted: 09/13/2017] [Indexed: 12/22/2022] Open
Abstract
Activation of the p53 tumor suppressor can lead to cell cycle arrest. The key mechanism of p53-mediated arrest is transcriptional downregulation of many cell cycle genes. In recent years it has become evident that p53-dependent repression is controlled by the p53–p21–DREAM–E2F/CHR pathway (p53–DREAM pathway). DREAM is a transcriptional repressor that binds to E2F or CHR promoter sites. Gene regulation and deregulation by DREAM shares many mechanistic characteristics with the retinoblastoma pRB tumor suppressor that acts through E2F elements. However, because of its binding to E2F and CHR elements, DREAM regulates a larger set of target genes leading to regulatory functions distinct from pRB/E2F. The p53–DREAM pathway controls more than 250 mostly cell cycle-associated genes. The functional spectrum of these pathway targets spans from the G1 phase to the end of mitosis. Consequently, through downregulating the expression of gene products which are essential for progression through the cell cycle, the p53–DREAM pathway participates in the control of all checkpoints from DNA synthesis to cytokinesis including G1/S, G2/M and spindle assembly checkpoints. Therefore, defects in the p53–DREAM pathway contribute to a general loss of checkpoint control. Furthermore, deregulation of DREAM target genes promotes chromosomal instability and aneuploidy of cancer cells. Also, DREAM regulation is abrogated by the human papilloma virus HPV E7 protein linking the p53–DREAM pathway to carcinogenesis by HPV. Another feature of the pathway is that it downregulates many genes involved in DNA repair and telomere maintenance as well as Fanconi anemia. Importantly, when DREAM function is lost, CDK inhibitor drugs employed in cancer treatment such as Palbociclib, Abemaciclib and Ribociclib can compensate for defects in early steps in the pathway upstream from cyclin/CDK complexes. In summary, the p53–p21–DREAM–E2F/CHR pathway controls a plethora of cell cycle genes, can contribute to cell cycle arrest and is a target for cancer therapy.
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73
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Lai TP, Zhang N, Noh J, Mender I, Tedone E, Huang E, Wright WE, Danuser G, Shay JW. A method for measuring the distribution of the shortest telomeres in cells and tissues. Nat Commun 2017; 8:1356. [PMID: 29116081 PMCID: PMC5676791 DOI: 10.1038/s41467-017-01291-z] [Citation(s) in RCA: 89] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Accepted: 09/07/2017] [Indexed: 01/23/2023] Open
Abstract
Improved methods to measure the shortest (not just average) telomere lengths (TLs) are needed. We developed Telomere Shortest Length Assay (TeSLA), a technique that detects telomeres from all chromosome ends from <1 kb to 18 kb using small amounts of input DNA. TeSLA improves the specificity and efficiency of TL measurements that is facilitated by user friendly image-processing software to automatically detect and annotate band sizes, calculate average TL, as well as the percent of the shortest telomeres. Compared with other TL measurement methods, TeSLA provides more information about the shortest telomeres. The length of telomeres was measured longitudinally in peripheral blood mononuclear cells during human aging, in tissues during colon cancer progression, in telomere-related diseases such as idiopathic pulmonary fibrosis, as well as in mice and other organisms. The results indicate that TeSLA is a robust method that provides a better understanding of the shortest length of telomeres. Short telomeres are a hallmark of senescence and can result in genomic instability as well as cancer progression. Here, the authors present TeSLA, a technique to accurately detect telomeres under 1 kb in length.
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Affiliation(s)
- Tsung-Po Lai
- Department of Cell Biology, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX, 75390, USA
| | - Ning Zhang
- Department of Cell Biology, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX, 75390, USA.,Department of Bioinformatics, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX, 75390, USA
| | - Jungsik Noh
- Department of Bioinformatics, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX, 75390, USA
| | - Ilgen Mender
- Department of Cell Biology, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX, 75390, USA
| | - Enzo Tedone
- Department of Cell Biology, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX, 75390, USA
| | - Ejun Huang
- Department of Cell Biology, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX, 75390, USA
| | - Woodring E Wright
- Department of Cell Biology, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX, 75390, USA
| | - Gaudenz Danuser
- Department of Cell Biology, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX, 75390, USA.,Department of Bioinformatics, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX, 75390, USA
| | - Jerry W Shay
- Department of Cell Biology, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX, 75390, USA.
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74
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Sagie S, Edni O, Weinberg J, Toubiana S, Kozlovski T, Frostig T, Katzin N, Bar-Am I, Selig S. Non-random length distribution of individual telomeres in immunodeficiency, centromeric instability and facial anomalies syndrome, type I. Hum Mol Genet 2017; 26:4244-4256. [PMID: 28973513 DOI: 10.1093/hmg/ddx313] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Accepted: 08/03/2017] [Indexed: 12/30/2022] Open
Abstract
Mutations in the de novo DNA methyltransferase DNMT3B lead to Immunodeficiency, Centromeric Instability and Facial anomalies (ICF) syndrome, type I. This syndrome is characterized, among other hypomethylated genomic loci, by severe subtelomeric hypomethylation that is associated with abnormally short telomere length. While it was demonstrated that the mean telomere length is significantly shorter in ICF type I cells, it is unknown whether all telomeres are equally vulnerable to shortening. To study this question we determined by combined telomere-FISH and spectral karyotyping the relative length of each individual telomere in lymphoblastoid cell lines (LCLs) generated from multiple ICF syndrome patients and control individuals. Here we confirm the short telomere lengths, and demonstrate that telomere length variance in the ICF patient group is much larger than in the control group, suggesting that not all telomeres shorten in a uniform manner. We identified a subgroup of telomeres whose relatively short lengths can distinguish with a high degree of certainty between a control and an ICF metaphase, proposing that in ICF syndrome cells, certain individual telomeres are consistently at greater risk to shorten than others. The majority of these telomeres display high sequence identity at the distal 2 kb of their subtelomeres, suggesting that the attenuation in DNMT3B methylation capacity affects individual telomeres to different degrees based, at least in part, on the adjacent subtelomeric sequence composition.
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Affiliation(s)
- Shira Sagie
- Molecular Medicine Laboratory, Rambam Health Care Campus and Rappaport Faculty of Medicine, Technion, Haifa 31096, Israel
| | - Omer Edni
- Molecular Medicine Laboratory, Rambam Health Care Campus and Rappaport Faculty of Medicine, Technion, Haifa 31096, Israel
| | - Joseph Weinberg
- Molecular Medicine Laboratory, Rambam Health Care Campus and Rappaport Faculty of Medicine, Technion, Haifa 31096, Israel
| | - Shir Toubiana
- Molecular Medicine Laboratory, Rambam Health Care Campus and Rappaport Faculty of Medicine, Technion, Haifa 31096, Israel
| | - Tal Kozlovski
- Department of Statistics and Operations Research, The Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 39040, Israel
| | - Tzviel Frostig
- Department of Statistics and Operations Research, The Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 39040, Israel
| | - Nirit Katzin
- Applied Spectral Imaging Ltd., Yokneam 2069200, Israel
| | - Irit Bar-Am
- Applied Spectral Imaging Ltd., Yokneam 2069200, Israel
| | - Sara Selig
- Molecular Medicine Laboratory, Rambam Health Care Campus and Rappaport Faculty of Medicine, Technion, Haifa 31096, Israel
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75
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Inherited Chromosomally Integrated Human Herpesvirus 6 Genomes Are Ancient, Intact, and Potentially Able To Reactivate from Telomeres. J Virol 2017; 91:JVI.01137-17. [PMID: 28835501 PMCID: PMC5660504 DOI: 10.1128/jvi.01137-17] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Accepted: 08/15/2017] [Indexed: 01/31/2023] Open
Abstract
The genomes of human herpesvirus 6A (HHV-6A) and HHV-6B have the capacity to integrate into telomeres, the essential capping structures of chromosomes that play roles in cancer and ageing. About 1% of people worldwide are carriers of chromosomally integrated HHV-6 (ciHHV-6), which is inherited as a genetic trait. Understanding the consequences of integration for the evolution of the viral genome, for the telomere, and for the risk of disease associated with carrier status is hampered by a lack of knowledge about ciHHV-6 genomes. Here, we report an analysis of 28 ciHHV-6 genomes and show that they are significantly divergent from the few modern nonintegrated HHV-6 strains for which complete sequences are currently available. In addition, ciHHV-6B genomes in Europeans are more closely related to each other than to ciHHV-6B genomes from China and Pakistan, suggesting regional variation of the trait. Remarkably, at least one group of European ciHHV-6B carriers has inherited the same ciHHV-6B genome, integrated in the same telomere allele, from a common ancestor estimated to have existed 24,500 ± 10,600 years ago. Despite the antiquity of some, and possibly most, germ line HHV-6 integrations, the majority of ciHHV-6B (95%) and ciHHV-6A (72%) genomes contain a full set of intact viral genes and therefore appear to have the capacity for viral gene expression and full reactivation. IMPORTANCE Inheritance of HHV-6A or HHV-6B integrated into a telomere occurs at a low frequency in most populations studied to date, but its characteristics are poorly understood. However, stratification of ciHHV-6 carriers in modern populations due to common ancestry is an important consideration for genome-wide association studies that aim to identify disease risks for these people. Here, we present full sequence analysis of 28 ciHHV-6 genomes and show that ciHHV-6B in many carriers with European ancestry most likely originated from ancient integration events in a small number of ancestors. We propose that ancient ancestral origins for ciHHV-6A and ciHHV-6B are also likely in other populations. Moreover, despite their antiquity, all of the ciHHV-6 genomes appear to retain the capacity to express viral genes, and most are predicted to be capable of full viral reactivation. These discoveries represent potentially important considerations in immunocompromised patients, in particular in organ transplantation and in stem cell therapy.
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76
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Ibáñez-Cabellos JS, Pérez-Machado G, Seco-Cervera M, Berenguer-Pascual E, García-Giménez JL, Pallardó FV. Acute telomerase components depletion triggers oxidative stress as an early event previous to telomeric shortening. Redox Biol 2017; 14:398-408. [PMID: 29055871 PMCID: PMC5650655 DOI: 10.1016/j.redox.2017.10.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Revised: 10/04/2017] [Accepted: 10/05/2017] [Indexed: 01/13/2023] Open
Abstract
Loss of function of dyskerin (DKC1), NOP10 and TIN2 are responsible for different inheritance patterns of Dyskeratosis congenita (DC; ORPHA1775). They are key components of telomerase (DKC1 and NOP10) and shelterin (TIN2), and play an important role in telomere homeostasis. They participate in several fundamental cellular processes by contributing to Dyskeratosis congenita through mechanisms that are not fully understood. Presence of oxidative stress was postulated to result from telomerase ablation. However, the resulting disturbed redox status can promote telomere attrition by generating a vicious circle, which promotes cellular senescence. This fact prompted us to study if acute loss of DKC1, NOP10 and TINF2 can promote redox disequilibrium as an early event when telomere shortening has not yet taken place. We generated siRNA-mediated (DKC1, NOP10 and TINF2) cell lines by RNA interference, which was confirmed by mRNA and protein expression analyses. No telomere shortening occurred in any silenced cell line. Depletion of H/ACA ribonucleoproteins DKC1 and NOP10 diminished telomerase activity via TERC down-regulation, and produced alterations in pseudouridylation and ribosomal biogenesis. An increase in the GSSG/GSH ratio, carbonylated proteins and oxidized peroxiredoxin-6 was observed, in addition to MnSOD and TRX1 overexpression in the siRNA DC cells. Likewise, high PARylation levels and high PARP1 protein expression were detected. In contrast, the silenced TINF2 cells did not alter any evaluated oxidative stress marker. Altogether these findings lead us to conclude that loss of DKC1 and NOP10 functions induces oxidative stress in a telomere shortening independent manner. Transient silencing of DKC1 and NOP10 genes produce oxidative stress. Cells depleted of DKC1 and NOP10 are susceptible to DNA damage. Acute DKC1 and NOP10 depletion disrupts RNA maturation. Oxidative stress is an early event previous to telomere shortening.
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Affiliation(s)
- José Santiago Ibáñez-Cabellos
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Institute of Health Carlos III, Valencia, Spain; Department of Physiology, Faculty of Medicine and Dentistry, University of Valencia, Valencia, Spain; INCLIVA Biomedical Research Institute, Valencia, Spain.
| | - Giselle Pérez-Machado
- Department of Physiology, Faculty of Medicine and Dentistry, University of Valencia, Valencia, Spain; INCLIVA Biomedical Research Institute, Valencia, Spain.
| | - Marta Seco-Cervera
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Institute of Health Carlos III, Valencia, Spain; Department of Physiology, Faculty of Medicine and Dentistry, University of Valencia, Valencia, Spain; INCLIVA Biomedical Research Institute, Valencia, Spain.
| | - Ester Berenguer-Pascual
- Department of Physiology, Faculty of Medicine and Dentistry, University of Valencia, Valencia, Spain.
| | - José Luis García-Giménez
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Institute of Health Carlos III, Valencia, Spain; Department of Physiology, Faculty of Medicine and Dentistry, University of Valencia, Valencia, Spain; INCLIVA Biomedical Research Institute, Valencia, Spain.
| | - Federico V Pallardó
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Institute of Health Carlos III, Valencia, Spain; Department of Physiology, Faculty of Medicine and Dentistry, University of Valencia, Valencia, Spain; INCLIVA Biomedical Research Institute, Valencia, Spain.
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77
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Mazumdar J, Chowdhury P, Bhattacharya T, Mondal BC, Ghosh U. Patients with Congenital Limb Anomaly Show Short Telomere, Shutdown of Telomerase and Deregulated Expression of Various Telomere-Associated Proteins in Peripheral Blood Mononuclear Cells-A Case Series. J Clin Diagn Res 2017; 11:GR01-GR06. [PMID: 28969156 DOI: 10.7860/jcdr/2017/26960.10516] [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: 02/28/2017] [Accepted: 05/24/2017] [Indexed: 11/24/2022]
Abstract
Congenital limb anomalies are outcome of improper bone formation during embryonic development when cells divide, differentiate with high rate. So, telomerase activity is essential to maintain telomere length for such highly dividing cells. Here, we report four cases of congenital limb anomalies with detailed structures of limbs along with other clinical manifestations of age less than two years. We compared telomere length, expression of telomerase and telomere-associated genes of Peripheral Blood Mononuclear Cells (PBMC) in patient and four age-matched normal individual. Patient-1 was diagnosed with congenital limb hypogenesis ectrodactyly sequence, an autosomal dominant disorder, showing absence of digits and fibula in upper and lower limb respectively. Both mother and grandmother of Patient-1 showed similar hypogenesis of limbs. Patient-2 showed bilateral clenched hand with arthrogryposis, microcephaly and holoprosencephaly. Both Patient-3 and Patient-4 has no radius in upper limb. Additionally, Paient-3 showed right sided orbital Space Occupying Lesion (SOL) and Paranasal Sinuses (PNS) whereas Patient-4 showed fused kidney with fanconi anaemia. Furthermore, all the patients showed shorter telomere length, inactive telomerase and de-regulated expression of telomere-associated proteins in PBMC compared with age-matched control group. So, we can conclude that congenital limb anomalies may be linked with telomeropathy and a study with large number of samples is required to firmly establish such association.
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Affiliation(s)
- Jayitri Mazumdar
- Senior Resident, Department of Paediatrics, Calcutta National Medical College and Hospital, Kolkata, West Bengal, India
| | - Priyanka Chowdhury
- Resaerch Scholar, Department of Biochemistry and Biophysics, University of Kalyani, West Bengal, India
| | - Tunisha Bhattacharya
- RMO Cum Clinical Tutor, Department of Paediatrics, Calcutta National Medical College and Hospital, Kolkata, West Bengal, India
| | - Badal Chandra Mondal
- Professor, Department of Paediatrics, Murshidabad Medical College, Berhampore, West Bengal, India
| | - Utpal Ghosh
- Assistant Professor, Department of Biochemistry and Biophysics, University of Kalyani, West Bengal, India
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78
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Affiliation(s)
- Jerry W Shay
- The University of Texas Southwestern Medical Center, Department of Cell Biology, 5323 Harry Hines Boulevard, Dallas, TX 75390, USA.
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79
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Systematic Analysis of the DNA Damage Response Network in Telomere Defective Budding Yeast. G3-GENES GENOMES GENETICS 2017; 7:2375-2389. [PMID: 28546384 PMCID: PMC5499144 DOI: 10.1534/g3.117.042283] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Functional telomeres are critically important to eukaryotic genetic stability. Scores of proteins and pathways are known to affect telomere function. Here, we report a series of related genome-wide genetic interaction screens performed on budding yeast cells with acute or chronic telomere defects. Genetic interactions were examined in cells defective in Cdc13 and Stn1, affecting two components of CST, a single stranded DNA (ssDNA) binding complex that binds telomeric DNA. For comparison, genetic interactions were also examined in cells with defects in Rfa3, affecting the major ssDNA binding protein, RPA, which has overlapping functions with CST at telomeres. In more complex experiments, genetic interactions were measured in cells lacking EXO1 or RAD9, affecting different aspects of the DNA damage response, and containing a cdc13-1 induced telomere defect. Comparing fitness profiles across these data sets helps build a picture of the specific responses to different types of dysfunctional telomeres. The experiments show that each context reveals different genetic interactions, consistent with the idea that each genetic defect causes distinct molecular defects. To help others engage with the large volumes of data, the data are made available via two interactive web-based tools: Profilyzer and DIXY. One particularly striking genetic interaction observed was that the chk1∆ mutation improved fitness of cdc13-1 exo1∆ cells more than other checkpoint mutations (ddc1∆, rad9∆, rad17∆, and rad24∆), whereas, in cdc13-1 cells, the effects of all checkpoint mutations were similar. We show that this can be explained by Chk1 stimulating resection-a new function for Chk1 in the eukaryotic DNA damage response network.
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80
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Behrens YL, Thomay K, Hagedorn M, Ebersold J, Henrich L, Nustede R, Schlegelberger B, Göhring G. Comparison of different methods for telomere length measurement in whole blood and blood cell subsets: Recommendations for telomere length measurement in hematological diseases. Genes Chromosomes Cancer 2017; 56:700-708. [DOI: 10.1002/gcc.22475] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Revised: 05/29/2017] [Accepted: 05/30/2017] [Indexed: 12/12/2022] Open
Affiliation(s)
- Yvonne Lisa Behrens
- Department of Human Genetics; Hannover Medical School; Carl-Neuberg-Str.1 Hannover 30625 Germany
| | - Kathrin Thomay
- Department of Human Genetics; Hannover Medical School; Carl-Neuberg-Str.1 Hannover 30625 Germany
| | - Maike Hagedorn
- Department of Human Genetics; Hannover Medical School; Carl-Neuberg-Str.1 Hannover 30625 Germany
| | - Juliane Ebersold
- Department of Human Genetics; Hannover Medical School; Carl-Neuberg-Str.1 Hannover 30625 Germany
| | - Lea Henrich
- Department of Human Genetics; Hannover Medical School; Carl-Neuberg-Str.1 Hannover 30625 Germany
| | - Rainer Nustede
- Pediatric surgery, Hannover Medical School; Carl-Neuberg-Str.1 Hannover 30625 Germany
| | - Brigitte Schlegelberger
- Department of Human Genetics; Hannover Medical School; Carl-Neuberg-Str.1 Hannover 30625 Germany
| | - Gudrun Göhring
- Department of Human Genetics; Hannover Medical School; Carl-Neuberg-Str.1 Hannover 30625 Germany
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81
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Gopalakrishnan V, Tan CR, Li S. Sequential phosphorylation of CST subunits by different cyclin-Cdk1 complexes orchestrate telomere replication. Cell Cycle 2017. [PMID: 28650257 DOI: 10.1080/15384101.2017.1312235] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
Abstract
Telomeres are nucleoprotein structures that cap the ends of linear chromosomes. Telomere homeostasis is central to maintaining genomic integrity. In budding yeast, Cdk1 phosphorylates the telomere-specific binding protein, Cdc13, promoting the recruitment of telomerase to telomere and thereby telomere elongation. Cdc13 is also an integral part of the CST (Cdc13-Stn1-Ten1) complex that is essential for telomere capping and counteracting telomerase-dependent telomere elongation. Therefore, telomere length homeostasis is a balance between telomerase-extendable and CST-unextendable states. In our earlier work, we showed that Cdk1 also phosphorylates Stn1 which occurs sequentially following Cdc13 phosphorylation during cell cycle progression. This stabilizes the CST complex at the telomere and results in telomerase inhibition. Hence Cdk1-dependent phosphorylations of Stn1 acts like a molecular switch that drives Cdc13 to complex with Stn1-Ten1 rather than with telomerase. However, the underlying mechanism of how a single cyclin-dependent kinase phosphorylates Cdc13 and Stn1 in temporally distinct windows is largely unclear. Here, we show that S phase cyclins are necessary for telomere maintenance. The S phase and mitotic cyclins facilitate Cdc13 and Stn1 phosphorylation respectively, to exert opposing outcomes at the telomere. Thus, our results highlight a previously unappreciated role for cyclins in telomere replication.
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Affiliation(s)
| | - Cherylin Ruiling Tan
- b Department of Biological Sciences , National University of Singapore , Singapore
| | - Shang Li
- a Program in Cancer and Stem Cell Biology , Duke-NUS Medical School , Singapore.,c Department of Physiology , Yong Loo Lin School of Medicine, National University of Singapore , Singapore
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82
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Abstract
Bacteria and viruses possess circular DNA, whereas eukaryotes with typically very large DNA molecules have had to evolve into linear chromosomes to circumvent the problem of supercoiling circular DNA of that size. Consequently, such organisms possess telomeres to cap chromosome ends. Telomeres are essentially tandem repeats of any DNA sequence that are present at the ends of chromosomes. Their biology has been an enigmatic one, involving various molecules interacting dynamically in an evolutionarily well-trimmed fashion. Telomeres range from canonical hexameric repeats in most eukaryotes to unimaginably random retrotransposons, which attach to chromosome ends and reverse-transcribe to DNA in some plants and insects. Telomeres invariably associate with specialised protein complexes that envelop it, also regulating access of the ends to legitimate enzymes involved in telomere metabolism. They also transcribe into repetitive RNA which also seems to be playing significant roles in telomere maintenance. Telomeres thus form the intersection of DNA, protein, and RNA molecules acting in concert to maintain chromosome integrity. Telomere biology is emerging to appear ever more complex than previously envisaged, with the continual discovery of more molecules and interplays at the telomeres. This review also includes a section dedicated to the history of telomere biology, and intends to target the scientific audience new to the field by rendering an understanding of the phenomenon of chromosome end protection at large, with more emphasis on the biology of human telomeres. The review provides an update on the field and mentions the questions that need to be addressed.
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Affiliation(s)
- Shriram Venkatesan
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, 117597 Singapore, Singapore.
| | - Aik Kia Khaw
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, 117597 Singapore, Singapore.
- Clinical Research Unit, Khoo Teck Puat Hospital, 768828 Singapore, Singapore.
| | - Manoor Prakash Hande
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, 117597 Singapore, Singapore.
- Tembusu College, National University of Singapore, 138598 Singapore, Singapore.
- VIT University, Vellore 632014, India.
- Mangalore University, Mangalore 574199, India.
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83
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Richeldi L, Collard HR, Jones MG. Idiopathic pulmonary fibrosis. Lancet 2017; 389:1941-1952. [PMID: 28365056 DOI: 10.1016/s0140-6736(17)30866-8] [Citation(s) in RCA: 1126] [Impact Index Per Article: 160.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Revised: 01/25/2017] [Accepted: 02/03/2017] [Indexed: 02/06/2023]
Abstract
Idiopathic pulmonary fibrosis is a prototype of chronic, progressive, and fibrotic lung disease. Healthy tissue is replaced by altered extracellular matrix and alveolar architecture is destroyed, which leads to decreased lung compliance, disrupted gas exchange, and ultimately respiratory failure and death. In less than a decade, understanding of the pathogenesis and management of this disease has been transformed, and two disease-modifying therapies have been approved, worldwide. In this Seminar, we summarise the presentation, pathophysiology, diagnosis, and treatment options available for patients with idiopathic pulmonary fibrosis. This disease has improved understanding of the mechanisms of lung fibrosis, and offers hope that similar approaches will transform the management of patients with other progressive fibrotic lung diseases.
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Affiliation(s)
- Luca Richeldi
- Unità Operativa Complessa di Pneumologia, Università Cattolica del Sacro Cuore, Fondazione Policlinico A. Gemelli, Rome, Italy; National Institute for Health Research Southampton Respiratory Biomedical Research Unit and Clinical and Experimental Sciences, University of Southampton, Southampton, UK.
| | - Harold R Collard
- Department of Medicine, University of California, San Francisco, San Francisco, CA, USA
| | - Mark G Jones
- National Institute for Health Research Southampton Respiratory Biomedical Research Unit and Clinical and Experimental Sciences, University of Southampton, Southampton, UK
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84
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Abstract
Chromosome ends are complex structures, which require a panel of factors for their elongation, replication, and protection. We describe here the mechanics of mammalian telomeres, dynamics and maintainance in relation to lamins. Multiple biochemical connections, including association of telomeres to the nuclear envelope and matrix, of telomeric proteins to lamins, and of lamin-associated proteins to chromosome ends, underline the interplay between lamins and telomeres. Paths toward senescence, such as defective telomere replication, altered heterochromatin organization, and impaired DNA repair, are common to lamins' and telomeres' dysfunction. The convergence of phenotypes can be interpreted through a model of dynamic, lamin-controlled functional platforms dedicated to the function of telomeres as fragile sites. The features of telomeropathies and laminopathies, and of animal models underline further overlapping aspects, including the alteration of stem cell compartments. We expect that future studies of basic biology and on aging will benefit from the analysis of this telomere-lamina interplay.
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Affiliation(s)
- Romina Burla
- a Dipartimento di Biologia e Biotecnologie "C. Darwin," Sapienza Università di Roma , Rome, Italy.,b Istituto di Biologia e Patologia Molecolari del CNR , Rome , Italy
| | - Mattia La Torre
- a Dipartimento di Biologia e Biotecnologie "C. Darwin," Sapienza Università di Roma , Rome, Italy
| | - Isabella Saggio
- a Dipartimento di Biologia e Biotecnologie "C. Darwin," Sapienza Università di Roma , Rome, Italy.,b Istituto di Biologia e Patologia Molecolari del CNR , Rome , Italy.,c Istituto Pasteur Fondazione Cenci Bolognetti , Rome , Italy
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85
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Eastley N, Ottolini B, Garrido C, Shaw JA, McCulloch TA, Ashford RU, Royle NJ. Telomere maintenance in soft tissue sarcomas. J Clin Pathol 2017; 70:371-377. [PMID: 28183782 PMCID: PMC5484030 DOI: 10.1136/jclinpath-2016-204151] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2016] [Accepted: 12/15/2016] [Indexed: 01/27/2023]
Abstract
Soft tissue sarcomas (STS) are a diverse group of heterogeneous malignant tumours derived from mesenchymal tissues. Over 50 different STS subtypes are recognised by WHO, which show a wide range of different biological behaviours and prognoses. At present, clinicians managing this complex group of tumours face several challenges. This is reflected by the relatively poor outcome of patients with STSs compared with many other solid malignant tumours. These include difficulties securing accurate diagnoses, a lack of effective systemic treatments and absence of any sensitive circulating biomarkers to monitor patients throughout their treatment and follow-up. In order to progress STS's cells must evade the usual cellular proliferative checkpoints, and then activate a telomere maintenance mechanism in order to achieve replicative immortality. The purpose of this review is to provide an overview of STS genetics focusing particularly on these mechanisms. We will also highlight some of the key barriers to improving outcome for patients with STS, and hypothesise how a better understanding of these genetic characteristics may impact on future STS management.
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Affiliation(s)
| | - Barbara Ottolini
- Department of Cancer Studies, University of Leicester, Leicester, UK
| | - Carmen Garrido
- Department of Genetics, University of Leicester, Leicester, UK
| | - Jacqueline A Shaw
- Department of Cancer Studies, University of Leicester, Leicester, UK
| | | | | | - Nicola J Royle
- Department of Genetics, University of Leicester, Leicester, UK
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86
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Hall AC, Ostrowski LA, Pietrobon V, Mekhail K. Repetitive DNA loci and their modulation by the non-canonical nucleic acid structures R-loops and G-quadruplexes. Nucleus 2017; 8:162-181. [PMID: 28406751 DOI: 10.1080/19491034.2017.1292193] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Cells have evolved intricate mechanisms to maintain genome stability despite allowing mutational changes to drive evolutionary adaptation. Repetitive DNA sequences, which represent the bulk of most genomes, are a major threat to genome stability often driving chromosome rearrangements and disease. The major source of repetitive DNA sequences and thus the most vulnerable constituents of the genome are the rDNA (rDNA) repeats, telomeres, and transposable elements. Maintaining the stability of these loci is critical to overall cellular fitness and lifespan. Therefore, cells have evolved mechanisms to regulate rDNA copy number, telomere length and transposon activity, as well as DNA repair at these loci. In addition, non-canonical structure-forming DNA motifs can also modulate the function of these repetitive DNA loci by impacting their transcription, replication, and stability. Here, we discuss key mechanisms that maintain rDNA repeats, telomeres, and transposons in yeast and human before highlighting emerging roles for non-canonical DNA structures at these repetitive loci.
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Affiliation(s)
- Amanda C Hall
- a Department of Laboratory Medicine and Pathobiology , Faculty of Medicine, University of Toronto , Toronto, Ontario , Canada
| | - Lauren A Ostrowski
- a Department of Laboratory Medicine and Pathobiology , Faculty of Medicine, University of Toronto , Toronto, Ontario , Canada
| | - Violena Pietrobon
- a Department of Laboratory Medicine and Pathobiology , Faculty of Medicine, University of Toronto , Toronto, Ontario , Canada
| | - Karim Mekhail
- a Department of Laboratory Medicine and Pathobiology , Faculty of Medicine, University of Toronto , Toronto, Ontario , Canada.,b Canada Research Chairs Program ; Faculty of Medicine, University of Toronto , Toronto, Ontario , Canada
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87
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Martínez P, Blasco MA. Telomere-driven diseases and telomere-targeting therapies. J Cell Biol 2017; 216:875-887. [PMID: 28254828 PMCID: PMC5379954 DOI: 10.1083/jcb.201610111] [Citation(s) in RCA: 168] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 01/03/2017] [Accepted: 01/09/2017] [Indexed: 01/19/2023] Open
Abstract
Martínez and Blasco review the molecular mechanisms underlying diseases associated with telomere dysfunction, including telomeropathies, age-related disorders, and cancer. Current and future therapeutic strategies to treat and prevent these diseases, including preclinical development of telomere-targeted therapies using mouse models, are discussed. Telomeres, the protective ends of linear chromosomes, shorten throughout an individual’s lifetime. Telomere shortening is proposed to be a primary molecular cause of aging. Short telomeres block the proliferative capacity of stem cells, affecting their potential to regenerate tissues, and trigger the development of age-associated diseases. Mutations in telomere maintenance genes are associated with pathologies referred to as telomere syndromes, including Hoyeraal-Hreidarsson syndrome, dyskeratosis congenita, pulmonary fibrosis, aplastic anemia, and liver fibrosis. Telomere shortening induces chromosomal instability that, in the absence of functional tumor suppressor genes, can contribute to tumorigenesis. In addition, mutations in telomere length maintenance genes and in shelterin components, the protein complex that protects telomeres, have been found to be associated with different types of cancer. These observations have encouraged the development of therapeutic strategies to treat and prevent telomere-associated diseases, namely aging-related diseases, including cancer. Here we review the molecular mechanisms underlying telomere-driven diseases and highlight recent advances in the preclinical development of telomere-targeted therapies using mouse models.
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Affiliation(s)
- Paula Martínez
- Telomeres and Telomerase Group, Molecular Oncology Program, Spanish National Cancer Centre, Madrid E-28029, Spain
| | - Maria A Blasco
- Telomeres and Telomerase Group, Molecular Oncology Program, Spanish National Cancer Centre, Madrid E-28029, Spain
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88
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Ozturk MB, Li Y, Tergaonkar V. Current Insights to Regulation and Role of Telomerase in Human Diseases. Antioxidants (Basel) 2017; 6:antiox6010017. [PMID: 28264499 PMCID: PMC5384180 DOI: 10.3390/antiox6010017] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Revised: 02/16/2017] [Accepted: 02/21/2017] [Indexed: 12/31/2022] Open
Abstract
The telomerase ribonucleoprotein complex has a pivotal role in regulating the proliferation and senescence of normal somatic cells as well as cancer cells. This complex is comprised mainly of telomerase reverse transcriptase (TERT), telomerase RNA component (TERC) and other associated proteins that function to elongate telomeres localized at the end of the chromosomes. While reactivation of telomerase is a major hallmark of most cancers, together with the synergistic activation of other oncogenic signals, deficiency in telomerase and telomeric proteins might lead to aging and senescence-associated disorders. Therefore, it is critically important to understand the canonical as well as non-canonical functions of telomerase through TERT to develop a therapeutic strategy against telomerase-related diseases. In this review, we shed light on the regulation and function of telomerase, and current therapeutic strategies against telomerase in cancer and age-related diseases.
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Affiliation(s)
- Mert Burak Ozturk
- Division of Cancer Genetics and Therapeutics, Laboratory of NFκB Signaling, Institute of Molecular and Cell Biology (IMCB), A*STAR (Agency for Science, Technology and Research), Singapore 138673, Singapore.
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore (NUS), Singapore 117597, Singapore.
| | - Yinghui Li
- Division of Cancer Genetics and Therapeutics, Laboratory of NFκB Signaling, Institute of Molecular and Cell Biology (IMCB), A*STAR (Agency for Science, Technology and Research), Singapore 138673, Singapore.
| | - Vinay Tergaonkar
- Division of Cancer Genetics and Therapeutics, Laboratory of NFκB Signaling, Institute of Molecular and Cell Biology (IMCB), A*STAR (Agency for Science, Technology and Research), Singapore 138673, Singapore.
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore (NUS), Singapore 117597, Singapore.
- Centre for Cancer Biology, University of South Australia and SA Pathology, Adelaide SA 5000, Australia.
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89
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Abstract
Telomerase is the essential reverse transcriptase required for linear chromosome maintenance in most eukaryotes. Telomerase supplements the tandem array of simple-sequence repeats at chromosome ends to compensate for the DNA erosion inherent in genome replication. The template for telomerase reverse transcriptase is within the RNA subunit of the ribonucleoprotein complex, which in cells contains additional telomerase holoenzyme proteins that assemble the active ribonucleoprotein and promote its function at telomeres. Telomerase is distinct among polymerases in its reiterative reuse of an internal template. The template is precisely defined, processively copied, and regenerated by release of single-stranded product DNA. New specificities of nucleic acid handling that underlie the catalytic cycle of repeat synthesis derive from both active site specialization and new motif elaborations in protein and RNA subunits. Studies of telomerase provide unique insights into cellular requirements for genome stability, tissue renewal, and tumorigenesis as well as new perspectives on dynamic ribonucleoprotein machines.
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Affiliation(s)
- R Alex Wu
- Department of Molecular and Cell Biology, University of California, Berkeley, California 94720-3202; , , ,
| | - Heather E Upton
- Department of Molecular and Cell Biology, University of California, Berkeley, California 94720-3202; , , ,
| | - Jacob M Vogan
- Department of Molecular and Cell Biology, University of California, Berkeley, California 94720-3202; , , ,
| | - Kathleen Collins
- Department of Molecular and Cell Biology, University of California, Berkeley, California 94720-3202; , , ,
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90
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Lin VTG, Pruitt HC, Samant RS, Shevde LA. Developing Cures: Targeting Ontogenesis in Cancer. Trends Cancer 2017; 3:126-136. [PMID: 28718443 DOI: 10.1016/j.trecan.2016.12.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2016] [Revised: 12/28/2016] [Accepted: 12/29/2016] [Indexed: 12/21/2022]
Abstract
Cancer has long been known to histologically resemble developing embryonic tissue. Since this early observation, a mounting body of evidence suggests that cancer mimics or co-opts developmental processes to facilitate tumor initiation and progression. Programs important in both normal ontogenesis and cancer progression broadly fall into three domains: the lineage commitment of pluripotent stem cells, the appropriation of primordial mechanisms of cell motility and invasion, and the influence of multiple aspects of the microenvironment on the parenchyma. In this review we discuss how derangements in these developmental pathways drive cancer progression with a particular focus on how they have emerged as targets of novel treatment strategies.
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Affiliation(s)
- Victor T G Lin
- Division of Hematology and Oncology, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL 35233, USA
| | - Hawley C Pruitt
- Department of Pathology, University of Alabama at Birmingham, Birmingham, AL 35233, USA
| | - Rajeev S Samant
- Department of Pathology, University of Alabama at Birmingham, Birmingham, AL 35233, USA; Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, AL 35233, USA
| | - Lalita A Shevde
- Department of Pathology, University of Alabama at Birmingham, Birmingham, AL 35233, USA; Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, AL 35233, USA.
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91
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TRF2 recruits ORC through TRFH domain dimerization. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2017; 1864:191-201. [DOI: 10.1016/j.bbamcr.2016.11.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Revised: 09/23/2016] [Accepted: 11/07/2016] [Indexed: 12/23/2022]
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92
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Telomere-associated aging disorders. Ageing Res Rev 2017; 33:52-66. [PMID: 27215853 PMCID: PMC9926533 DOI: 10.1016/j.arr.2016.05.009] [Citation(s) in RCA: 98] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Revised: 05/17/2016] [Accepted: 05/19/2016] [Indexed: 01/25/2023]
Abstract
Telomeres are dynamic nucleoprotein-DNA structures that cap and protect linear chromosome ends. Several monogenic inherited diseases that display features of human premature aging correlate with shortened telomeres, and are referred to collectively as telomeropathies. These disorders have overlapping symptoms and a common underlying mechanism of telomere dysfunction, but also exhibit variable symptoms and age of onset, suggesting they fall along a spectrum of disorders. Primary telomeropathies are caused by defects in the telomere maintenance machinery, whereas secondary telomeropathies have some overlapping symptoms with primary telomeropathies, but are generally caused by mutations in DNA repair proteins that contribute to telomere preservation. Here we review both the primary and secondary telomeropathies, discuss potential mechanisms for tissue specificity and age of onset, and highlight outstanding questions in the field and future directions toward elucidating disease etiology and developing therapeutic strategies.
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93
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Heidenreich B, Kumar R. TERT promoter mutations in telomere biology. MUTATION RESEARCH-REVIEWS IN MUTATION RESEARCH 2016; 771:15-31. [PMID: 28342451 DOI: 10.1016/j.mrrev.2016.11.002] [Citation(s) in RCA: 130] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Accepted: 11/10/2016] [Indexed: 02/07/2023]
Abstract
Telomere repeats at chromosomal ends, critical to genome integrity, are maintained through an elaborate network of proteins and pathways. Shelterin complex proteins shield telomeres from induction of DNA damage response to overcome end protection problem. A specialized ribonucleic protein, telomerase, maintains telomere homeostasis through repeat addition to counter intrinsic shortcomings of DNA replication that leads to gradual sequence shortening in successive mitoses. The biogenesis and recruitment of telomerase composed of telomerase reverse transcriptase (TERT) subunit and an RNA component, takes place through the intricate machinery that involves an elaborate number of molecules. The synthesis of telomeres remains a controlled and limited process. Inherited mutations in the molecules involved in the process directly or indirectly cause telomeropathies. Telomerase, while present in stem cells, is deactivated due to epigenetic silencing of the rate-limiting TERT upon differentiation in most of somatic cells with a few exceptions. However, in most of the cancer cells telomerase reactivation remains a ubiquitous process and constitutes one of the major hallmarks. Discovery of mutations within the core promoter of the TERT gene that create de novo binding sites for E-twenty-six (ETS) transcription factors provided a mechanism for cancer-specific telomerase reactivation. The TERT promoter mutations occur mainly in tumors from tissues with low rates of self-renewal. In melanoma, glioma, hepatocellular carcinoma, urothelial carcinoma and others, the promoter mutations have been shown to define subsets of patients with adverse disease outcomes, associate with increased transcription of TERT, telomerase reactivation and affect telomere length; in stem cells the mutations inhibit TERT silencing following differentiation into adult cells. The TERT promoter mutations cause an epigenetic switch on the mutant allele along with recruitment of pol II following the binding of GABPA/B1 complex that leads to mono-allelic expression. Thus, the TERT promoter mutations hold potential as biomarkers as well as future therapeutic targets.
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Affiliation(s)
| | - Rajiv Kumar
- Division of Molecular Genetic Epidemiology; German Consortium for Translational Cancer Research (DKTK), German Cancer Research Center, 69120 Heidelberg, Germany.
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94
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Holohan B, Kim W, Lai TP, Hoshiyama H, Zhang N, Alazami AM, Wright WE, Meyn MS, Alkuraya FS, Shay JW. Impaired telomere maintenance in Alazami syndrome patients with LARP7 deficiency. BMC Genomics 2016; 17:749. [PMID: 27766953 PMCID: PMC5073984 DOI: 10.1186/s12864-016-3093-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Loss of function in genes required for telomere maintenance result in disorders known as telomeropathies, which are characterized by a pattern of symptoms including generalized and specific lymphocytopenias as well as very short telomere length and disease anticipation. METHODS Because human LARP7 is the most likely ortholog of the Tetrahymena p65 protein, which is required for telomerase activity in that organism, we investigated the effects of LARP7 silencing in human cells as well as in two distinct families with Alazami syndrome (loss of function of LARP7). RESULTS Depletion of LARP7 caused a reduction in telomerase enzymatic activity and progressively shorter telomeres in human cancer cell lines. Alazami syndrome patients from two separate cohorts exhibited very short lymphocyte telomeres. Further, wild-type offspring of LARP7 mutant individuals also had very short telomeres, comparable to what is observed in telomerase (hTERT) mutant cohorts. CONCLUSIONS Together, these experiments demonstrate that in addition to the readily apparent developmental disorder associated with LARP7 deficiency, an underlying telomeropathy exists even in unaffected siblings of these individuals.
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Affiliation(s)
- Brody Holohan
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Wanil Kim
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Tsung-Po Lai
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Hirotoshi Hoshiyama
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Ning Zhang
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Anas M Alazami
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Woodring E Wright
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - M Stephen Meyn
- The Hospital for Sick Children, Department of Pediatric and Molecular Genetics, University of Toronto, Toronto, ON, M5s1A8, Canada
| | - Fowzan S Alkuraya
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia.,Department of Anatomy and Cell, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia.,Department of Pediatrics, King Khalid University Hospital and College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Jerry W Shay
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA. .,Center for Excellence in Genomics Medicine Research, King Abdulaziz University, Jeddah, Saudi Arabia.
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95
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MacNeil DE, Bensoussan HJ, Autexier C. Telomerase Regulation from Beginning to the End. Genes (Basel) 2016; 7:genes7090064. [PMID: 27649246 PMCID: PMC5042394 DOI: 10.3390/genes7090064] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Revised: 08/25/2016] [Accepted: 08/26/2016] [Indexed: 12/11/2022] Open
Abstract
The vast body of literature regarding human telomere maintenance is a true testament to the importance of understanding telomere regulation in both normal and diseased states. In this review, our goal was simple: tell the telomerase story from the biogenesis of its parts to its maturity as a complex and function at its site of action, emphasizing new developments and how they contribute to the foundational knowledge of telomerase and telomere biology.
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Affiliation(s)
- Deanna Elise MacNeil
- Bloomfield Centre for Research in Aging, Lady Davis Institute for Medical Research, Jewish General Hospital, 3755 Côte Ste-Catherine Road, Montréal, QC H3T 1E2, Canada.
- Room M-29, Department of Anatomy and Cell Biology, McGill University, 3640 University Street, Montréal, QC H3A 0C7, Canada.
| | - Hélène Jeanne Bensoussan
- Bloomfield Centre for Research in Aging, Lady Davis Institute for Medical Research, Jewish General Hospital, 3755 Côte Ste-Catherine Road, Montréal, QC H3T 1E2, Canada.
- Room M-29, Department of Anatomy and Cell Biology, McGill University, 3640 University Street, Montréal, QC H3A 0C7, Canada.
| | - Chantal Autexier
- Bloomfield Centre for Research in Aging, Lady Davis Institute for Medical Research, Jewish General Hospital, 3755 Côte Ste-Catherine Road, Montréal, QC H3T 1E2, Canada.
- Room M-29, Department of Anatomy and Cell Biology, McGill University, 3640 University Street, Montréal, QC H3A 0C7, Canada.
- Department of Experimental Medicine, McGill University, 1110 Pins Avenue West, Room 101, Montréal, QC H3A 1A3, Canada.
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96
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Filipović J, Joksić G, Vujić D, Joksić I, Mrasek K, Weise A, Liehr T. First molecular-cytogenetic characterization of Fanconi anemia fragile sites in primary lymphocytes of FA-D2 patients in different stages of the disease. Mol Cytogenet 2016; 9:70. [PMID: 27625703 PMCID: PMC5020439 DOI: 10.1186/s13039-016-0280-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Accepted: 08/26/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Fanconi anemia (FA) is a chromosomal instability syndrome characterized by increased frequency of chromosomal breakages, chromosomal radial figures and accelerated telomere shortening. In this work we performed detailed molecular-cytogenetic characterization of breakpoints in primary lymphocytes of FA-D2 patients in different stages of the disease using fluorescent in situ hybridization. RESULTS We found that chromosomal breakpoints co-localize on the molecular level with common fragile sites, whereas their distribution pattern depends on the severity of the disease. Telomere quantitative fluorescent in situ hybridization revealed that telomere fusions and radial figures, especially radials which involve telomere sequences are the consequence of critically shortened telomeres that increase with the disease progression and could be considered as a predictive parameter during the course of the disease. Sex chromosomes in FA cells are also involved in radial formation indicating that specific X chromosome regions share homology with autosomes and also could serve as repair templates in resolving DNA damage. CONCLUSIONS FA-D2 chromosomal breakpoints co-localize with common fragile sites, but their distribution pattern depends on the disease stage. Telomere fusions and radials figures which involve telomere sequences are the consequence of shortened telomeres, increase with disease progression and could be of predictive value.
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Affiliation(s)
- Jelena Filipović
- Vinca Institute of Nuclear Sciences, University of Belgrade, Mike Petrovica Alasa 12-14, Belgrade, 11001 Serbia
| | - Gordana Joksić
- Vinca Institute of Nuclear Sciences, University of Belgrade, Mike Petrovica Alasa 12-14, Belgrade, 11001 Serbia
| | - Dragana Vujić
- Mother and Child Health Care Institute of Serbia, "Dr Vukan Cupic", Radoja Dakica 6, Belgrade, 11070 Serbia
| | - Ivana Joksić
- Vinca Institute of Nuclear Sciences, University of Belgrade, Mike Petrovica Alasa 12-14, Belgrade, 11001 Serbia
| | - Kristin Mrasek
- Institute of Human Genetics, Jena University Hospital, Friedrich Schiller University, Kollegiengasse 10, Jena, D-07743 Germany
| | - Anja Weise
- Institute of Human Genetics, Jena University Hospital, Friedrich Schiller University, Kollegiengasse 10, Jena, D-07743 Germany
| | - Thomas Liehr
- Institute of Human Genetics, Jena University Hospital, Friedrich Schiller University, Kollegiengasse 10, Jena, D-07743 Germany
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97
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Transcription Regulation of the Human Telomerase Reverse Transcriptase (hTERT) Gene. Genes (Basel) 2016; 7:genes7080050. [PMID: 27548225 PMCID: PMC4999838 DOI: 10.3390/genes7080050] [Citation(s) in RCA: 101] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Revised: 07/23/2016] [Accepted: 08/01/2016] [Indexed: 12/11/2022] Open
Abstract
Embryonic stem cells and induced pluripotent stem cells have the ability to maintain their telomere length via expression of an enzymatic complex called telomerase. Similarly, more than 85%–90% of cancer cells are found to upregulate the expression of telomerase, conferring them with the potential to proliferate indefinitely. Telomerase Reverse Transcriptase (TERT), the catalytic subunit of telomerase holoenzyme, is the rate-limiting factor in reconstituting telomerase activity in vivo. To date, the expression and function of the human Telomerase Reverse Transcriptase (hTERT) gene are known to be regulated at various molecular levels (including genetic, mRNA, protein and subcellular localization) by a number of diverse factors. Among these means of regulation, transcription modulation is the most important, as evident in its tight regulation in cancer cell survival as well as pluripotent stem cell maintenance and differentiation. Here, we discuss how hTERT gene transcription is regulated, mainly focusing on the contribution of trans-acting factors such as transcription factors and epigenetic modifiers, as well as genetic alterations in hTERT proximal promoter.
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98
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Simon AJ, Lev A, Zhang Y, Weiss B, Rylova A, Eyal E, Kol N, Barel O, Cesarkas K, Soudack M, Greenberg-Kushnir N, Rhodes M, Wiest DL, Schiby G, Barshack I, Katz S, Pras E, Poran H, Reznik-Wolf H, Ribakovsky E, Simon C, Hazou W, Sidi Y, Lahad A, Katzir H, Sagie S, Aqeilan HA, Glousker G, Amariglio N, Tzfati Y, Selig S, Rechavi G, Somech R. Mutations in STN1 cause Coats plus syndrome and are associated with genomic and telomere defects. J Exp Med 2016; 213:1429-40. [PMID: 27432940 PMCID: PMC4986528 DOI: 10.1084/jem.20151618] [Citation(s) in RCA: 84] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2015] [Accepted: 06/10/2016] [Indexed: 12/18/2022] Open
Abstract
The analysis of individuals with telomere defects may shed light on the delicate interplay of factors controlling genome stability, premature aging, and cancer. We herein describe two Coats plus patients with telomere and genomic defects; both harbor distinct, novel mutations in STN1, a member of the human CTC1-STN1-TEN1 (CST) complex, thus linking this gene for the first time to a human telomeropathy. We characterized the patients' phenotype, recapitulated it in a zebrafish model and rescued cellular and clinical aspects by the ectopic expression of wild-type STN1 or by thalidomide treatment. Interestingly, a significant lengthy control of the gastrointestinal bleeding in one of our patients was achieved by thalidomide treatment, exemplifying a successful bed-to-bench-and-back approach.
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Affiliation(s)
- Amos J Simon
- Pediatric Department A and Immunology Service, Jeffrey Modell Foundation Center, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel Hashomer, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel Division of Haematology and Bone Marrow Transplantation, Sheba Medical Center, Tel Hashomer, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel The Wohl Institute for Translational Medicine, Sheba Medical Center, Tel Hashomer, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Atar Lev
- Pediatric Department A and Immunology Service, Jeffrey Modell Foundation Center, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel Hashomer, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel The Wohl Institute for Translational Medicine, Sheba Medical Center, Tel Hashomer, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Yong Zhang
- Blood Cell Development and Function Program, Fox Chase Cancer Center, Philadelphia, PA 19111
| | - Batia Weiss
- The Wohl Institute for Translational Medicine, Sheba Medical Center, Tel Hashomer, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel Pediatric Gastroenterology and Nutrition Unit, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel Hashomer, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Anna Rylova
- Pediatric Department A and Immunology Service, Jeffrey Modell Foundation Center, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel Hashomer, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Eran Eyal
- The Wohl Institute for Translational Medicine, Sheba Medical Center, Tel Hashomer, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel Sheba Cancer Research Center, Sheba Medical Center, Tel Hashomer, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Nitzan Kol
- The Wohl Institute for Translational Medicine, Sheba Medical Center, Tel Hashomer, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel Sheba Cancer Research Center, Sheba Medical Center, Tel Hashomer, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Ortal Barel
- The Wohl Institute for Translational Medicine, Sheba Medical Center, Tel Hashomer, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel Sheba Cancer Research Center, Sheba Medical Center, Tel Hashomer, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Keren Cesarkas
- The Wohl Institute for Translational Medicine, Sheba Medical Center, Tel Hashomer, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel Sheba Cancer Research Center, Sheba Medical Center, Tel Hashomer, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Michalle Soudack
- Imaging Unit, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel Hashomer, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Noa Greenberg-Kushnir
- Blood Cell Development and Function Program, Fox Chase Cancer Center, Philadelphia, PA 19111
| | - Michele Rhodes
- Blood Cell Development and Function Program, Fox Chase Cancer Center, Philadelphia, PA 19111
| | - David L Wiest
- Blood Cell Development and Function Program, Fox Chase Cancer Center, Philadelphia, PA 19111
| | - Ginette Schiby
- The Wohl Institute for Translational Medicine, Sheba Medical Center, Tel Hashomer, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel Department of Pathology, Sheba Medical Center, Tel Hashomer, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Iris Barshack
- Department of Pathology, Sheba Medical Center, Tel Hashomer, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Shulamit Katz
- Pediatric Department A and Immunology Service, Jeffrey Modell Foundation Center, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel Hashomer, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Elon Pras
- The Danek Gertner Institute of Human Genetics, Sheba Medical Center, Tel Hashomer, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Hana Poran
- The Danek Gertner Institute of Human Genetics, Sheba Medical Center, Tel Hashomer, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Haike Reznik-Wolf
- The Danek Gertner Institute of Human Genetics, Sheba Medical Center, Tel Hashomer, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Elena Ribakovsky
- Division of Haematology and Bone Marrow Transplantation, Sheba Medical Center, Tel Hashomer, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Carlos Simon
- Division of Gastroenterology, Sheba Medical Center, Tel Hashomer, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Wadi Hazou
- Department of Internal Medicine C, Sheba Medical Center, Tel Hashomer, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Yechezkel Sidi
- Department of Internal Medicine C, Sheba Medical Center, Tel Hashomer, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Avishay Lahad
- Pediatric Gastroenterology and Nutrition Unit, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel Hashomer, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Hagar Katzir
- Laboratory of Molecular Medicine, Rambam Health Care Campus and Rappaport Faculty of Medicine and Research Institute, Technion, Haifa 8875361, Israel
| | - Shira Sagie
- Laboratory of Molecular Medicine, Rambam Health Care Campus and Rappaport Faculty of Medicine and Research Institute, Technion, Haifa 8875361, Israel
| | - Haifa A Aqeilan
- Department of Genetics, The Silberman Institute of Life Sciences, Hebrew University of Jerusalem, Edmond Safra Campus, Givat Ram, Jerusalem 9190401, Israel
| | - Galina Glousker
- Department of Genetics, The Silberman Institute of Life Sciences, Hebrew University of Jerusalem, Edmond Safra Campus, Givat Ram, Jerusalem 9190401, Israel
| | - Ninette Amariglio
- Division of Haematology and Bone Marrow Transplantation, Sheba Medical Center, Tel Hashomer, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel The Wohl Institute for Translational Medicine, Sheba Medical Center, Tel Hashomer, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel Sheba Cancer Research Center, Sheba Medical Center, Tel Hashomer, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel The Everard and Mina Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan 5290002, Israel
| | - Yehuda Tzfati
- Department of Genetics, The Silberman Institute of Life Sciences, Hebrew University of Jerusalem, Edmond Safra Campus, Givat Ram, Jerusalem 9190401, Israel
| | - Sara Selig
- Laboratory of Molecular Medicine, Rambam Health Care Campus and Rappaport Faculty of Medicine and Research Institute, Technion, Haifa 8875361, Israel
| | - Gideon Rechavi
- The Wohl Institute for Translational Medicine, Sheba Medical Center, Tel Hashomer, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel Sheba Cancer Research Center, Sheba Medical Center, Tel Hashomer, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Raz Somech
- Pediatric Department A and Immunology Service, Jeffrey Modell Foundation Center, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel Hashomer, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel The Wohl Institute for Translational Medicine, Sheba Medical Center, Tel Hashomer, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
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Escribano A, Pastor S, Reula A, Castillo S, Vicente S, Sanz F, Casas F, Torres M, Fernández-Fabrellas E, Codoñer-Franch P, Dasí F. Accelerated telomere attrition in children and teenagers with α1-antitrypsin deficiency. Eur Respir J 2016; 48:350-8. [PMID: 27390278 DOI: 10.1183/13993003.00176-2016] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2016] [Accepted: 05/17/2016] [Indexed: 12/20/2022]
Abstract
Numerous studies have shown that oxidative stress accelerates telomere shortening in several lung pathologies. Since oxidative stress is involved in the pathophysiology of α1-antitrypsin deficiency (AATD), we hypothesised that telomere shortening would be accelerated in AATD patients. This study aimed to assess telomere length in AATD patients and to study its association with α1-antitrypsin phenotypes.Telomere length, telomerase activity, telomerase reverse transcriptase (hTERT) expression and biomarkers of oxidative stress were measured in 62 children and teenagers (aged 2–18 years) diagnosed with AATD and 18 controls (aged 3–16 years).Our results show that intermediate-risk (MZ; SZ) and high-risk (ZZ) AATD patients have significantly shorter telomeres and increased oxidative stress than controls. Correlation studies indicate that telomere length was related to oxidative stress markers in AATD patients. Multiple hypothesis testing revealed an association between telomere length, telomerase activity, hTERT expression and AATD phenotypes; high-risk patients showed shorter telomeres, lower hTERT expression and decreased telomerase activity than intermediate-risk and low-risk patients.AATD patients show evidence of increased oxidative stress leading to telomere attrition. An association between telomere and α1-antitrypsin phenotypes is observed suggesting that telomere length could be a promising biomarker for AATD disease progression.
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100
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Lin J, Countryman P, Chen H, Pan H, Fan Y, Jiang Y, Kaur P, Miao W, Gurgel G, You C, Piehler J, Kad NM, Riehn R, Opresko PL, Smith S, Tao YJ, Wang H. Functional interplay between SA1 and TRF1 in telomeric DNA binding and DNA-DNA pairing. Nucleic Acids Res 2016; 44:6363-76. [PMID: 27298259 PMCID: PMC5291270 DOI: 10.1093/nar/gkw518] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Accepted: 05/30/2016] [Indexed: 12/23/2022] Open
Abstract
Proper chromosome alignment and segregation during mitosis depend on cohesion between sister chromatids. Cohesion is thought to occur through the entrapment of DNA within the tripartite ring (Smc1, Smc3 and Rad21) with enforcement from a fourth subunit (SA1/SA2). Surprisingly, cohesin rings do not play a major role in sister telomere cohesion. Instead, this role is replaced by SA1 and telomere binding proteins (TRF1 and TIN2). Neither the DNA binding property of SA1 nor this unique telomere cohesion mechanism is understood. Here, using single-molecule fluorescence imaging, we discover that SA1 displays two-state binding on DNA: searching by one-dimensional (1D) free diffusion versus recognition through subdiffusive sliding at telomeric regions. The AT-hook motif in SA1 plays dual roles in modulating non-specific DNA binding and subdiffusive dynamics over telomeric regions. TRF1 tethers SA1 within telomeric regions that SA1 transiently interacts with. SA1 and TRF1 together form longer DNA–DNA pairing tracts than with TRF1 alone, as revealed by atomic force microscopy imaging. These results suggest that at telomeres cohesion relies on the molecular interplay between TRF1 and SA1 to promote DNA–DNA pairing, while along chromosomal arms the core cohesin assembly might also depend on SA1 1D diffusion on DNA and sequence-specific DNA binding.
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Affiliation(s)
- Jiangguo Lin
- School of Bioscience and Engineering, South China University of Technology, Guangzhou, Guangdong 510006, P.R. China Physics Department, North Carolina State University, Raleigh, North Carolina, NC 27695, USA
| | - Preston Countryman
- Physics Department, North Carolina State University, Raleigh, North Carolina, NC 27695, USA
| | - Haijiang Chen
- Department of BioSciences, Rice University, Houston, TX 77005, USA Institute of Microbiology and College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, P.R. China
| | - Hai Pan
- Physics Department, North Carolina State University, Raleigh, North Carolina, NC 27695, USA
| | - Yanlin Fan
- Department of BioSciences, Rice University, Houston, TX 77005, USA
| | - Yunyun Jiang
- Department of BioSciences, Rice University, Houston, TX 77005, USA
| | - Parminder Kaur
- Physics Department, North Carolina State University, Raleigh, North Carolina, NC 27695, USA
| | - Wang Miao
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan 450014, P.R. China
| | - Gisele Gurgel
- Biomanufacturing Training and Education Center, North Carolina State University, Raleigh, North Carolina, NC 27695, USA
| | - Changjiang You
- Division of Biophysics, Universität Osnabrück, Barbarstrasse 11, 49076 Osnabrück, Germany
| | - Jacob Piehler
- Division of Biophysics, Universität Osnabrück, Barbarstrasse 11, 49076 Osnabrück, Germany
| | - Neil M Kad
- School of Biosciences, University of Kent, Canterbury, Kent CT2 7NJ, UK
| | - Robert Riehn
- Physics Department, North Carolina State University, Raleigh, North Carolina, NC 27695, USA
| | - Patricia L Opresko
- Department of Environmental and Occupational Health, University of Pittsburgh, PA 15213, USA
| | - Susan Smith
- Kimmel Center for Biology and Medicine at the Skirball Institute, Department of Pathology, New York University School of Medicine, New York, NY 10016, USA
| | - Yizhi Jane Tao
- Department of BioSciences, Rice University, Houston, TX 77005, USA
| | - Hong Wang
- Physics Department, North Carolina State University, Raleigh, North Carolina, NC 27695, USA
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