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Yegorov YE. Olovnikov, Telomeres, and Telomerase. Is It Possible to Prolong a Healthy Life? BIOCHEMISTRY. BIOKHIMIIA 2023; 88:1704-1718. [PMID: 38105192 DOI: 10.1134/s0006297923110032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 08/29/2023] [Accepted: 08/31/2023] [Indexed: 12/19/2023]
Abstract
The science of telomeres and telomerase has made tremendous progress in recent decades. In this review, we consider it first in a historical context (the Carrel-Hayflick-Olovnikov-Blackburn chain of discoveries) and then review current knowledge on the telomere structure and dynamics in norm and pathology. Central to the review are consequences of the telomere shortening, including telomere position effects, DNA damage signaling, and increased genetic instability. Cell senescence and role of telomere length in its development are discussed separately. Therapeutic aspects and risks of telomere lengthening methods including use of telomerase and other approaches are also discussed.
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Affiliation(s)
- Yegor E Yegorov
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, 119991, Russia.
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2
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Zhao P, Ning J, Huang J, Wei B, Wang Z, Huang X. High Expression of MORC2 is Associated with Poor Clinical Outcomes and Immune Infiltrates in Colon Adenocarcinoma. Int J Gen Med 2023; 16:4595-4615. [PMID: 37850194 PMCID: PMC10577261 DOI: 10.2147/ijgm.s420715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2023] [Accepted: 09/07/2023] [Indexed: 10/19/2023] Open
Abstract
Purpose Microrchidia 2 (MORC2) is a universally expressed molecule that has recently been identified as a chromatin modulator and elevated in many malignancies. However, its prognostic value and immunological role of MORC2 in colon adenocarcinoma (COAD) have never been illustrated. Methods The clinical parameters and MORC2 expression datasets of COAD patients were obtained from The Cancer Genome Atlas (TCGA). Cancer and adjacent tissue specimens from surgically resected COAD patients were collected, and quantitative real-time PCR was used to detect MORC2 expression. Differentially expressed genes related to MORC2 were discovered and used for functional enrichment analysis. The diagnostic and prognostic values of MORC2 in COAD were conducted using receiver operating characteristics (ROC), Kaplan-Meier survival curve analysis, PrognoScan, Gene Expression Profiling Interactive Analysis (GEPIA) public databases and nomograms. Eventually, the association of MORC2 with tumor microenvironment was analyzed by using TIMER and GSVA package of R (v3.6.3). Results MORC2 expression was upregulated in COAD tissues, and the RT-qPCR results further verified the reliability of our differential analysis at the transcriptional level. Additionally, higher expression of MORC2 was correlated to a poor prognosis for COAD patients. MORC2 was an independent prognostic factor for COAD and could be a diagnostic factor for early COAD. Furthermore, MORC2 expression was positively correlated with immune cells such as NK cells, TFH cells and so on. Conclusion The findings demonstrated that overexpression of MORC2 was correlated with worse prognosis and immune infiltrates of COAD. MORC2 can serve as a reliable diagnostic and prognostic biomarker and a target of immunotherapy for COAD patients.
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Affiliation(s)
- Peizhuang Zhao
- Department of Geriatrics and Gastroenterology, the First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, People's Republic of China
| | - Jiajia Ning
- Department of Geriatrics and Gastroenterology, the First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, People's Republic of China
| | - Jun Huang
- Department of Geriatrics and Gastroenterology, the First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, People's Republic of China
| | - Binqian Wei
- Department of Geriatrics and Gastroenterology, the First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, People's Republic of China
| | - Zhen Wang
- Department of Geriatrics and Gastroenterology, the First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, People's Republic of China
| | - Xue Huang
- Department of Geriatrics and Gastroenterology, the First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, People's Republic of China
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3
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Banerjee S, Galarza-Muñoz G, Garcia-Blanco MA. Role of RNA Alternative Splicing in T Cell Function and Disease. Genes (Basel) 2023; 14:1896. [PMID: 37895245 PMCID: PMC10606310 DOI: 10.3390/genes14101896] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Revised: 09/24/2023] [Accepted: 09/26/2023] [Indexed: 10/29/2023] Open
Abstract
Alternative RNA splicing, a ubiquitous mechanism of gene regulation in eukaryotes, expands genome coding capacity and proteomic diversity. It has essential roles in all aspects of human physiology, including immunity. This review highlights the importance of RNA alternative splicing in regulating immune T cell function. We discuss how mutations that affect the alternative splicing of T cell factors can contribute to abnormal T cell function and ultimately lead to autoimmune diseases. We also explore the potential applications of strategies that target the alternative splicing changes of T cell factors. These strategies could help design therapeutic approaches to treat autoimmune disorders and improve immunotherapy.
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Affiliation(s)
- Shefali Banerjee
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia, Charlottesville, VA 22903, USA;
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77550, USA
| | | | - Mariano A. Garcia-Blanco
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia, Charlottesville, VA 22903, USA;
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77550, USA
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4
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Yang R, Han Y, Guan X, Hong Y, Meng J, Ding S, Long Q, Yi W. Regulation and clinical potential of telomerase reverse transcriptase (TERT/hTERT) in breast cancer. Cell Commun Signal 2023; 21:218. [PMID: 37612721 PMCID: PMC10463831 DOI: 10.1186/s12964-023-01244-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Accepted: 07/23/2023] [Indexed: 08/25/2023] Open
Abstract
Telomerase reverse transcriptase (TERT/hTERT) serves as the pivotal catalytic subunit of telomerase, a crucial enzyme responsible for telomere maintenance and human genome stability. The high activation of hTERT, observed in over 90% of tumors, plays a significant role in tumor initiation and progression. An in-depth exploration of hTERT activation mechanisms in cancer holds promise for advancing our understanding of the disease and developing more effective treatment strategies. In breast cancer, the expression of hTERT is regulated by epigenetic, transcriptional, post-translational modification mechanisms and DNA variation. Besides its canonical function in telomere maintenance, hTERT exerts non-canonical roles that contribute to disease progression through telomerase-independent mechanisms. This comprehensive review summarizes the regulatory mechanisms governing hTERT in breast cancer and elucidates the functional implications of its activation. Given the overexpression of hTERT in most breast cancer cells, the detection of hTERT and its associated molecules are potential for enhancing early screening and prognostic evaluation of breast cancer. Although still in its early stages, therapeutic approaches targeting hTERT and its regulatory molecules show promise as viable strategies for breast cancer treatment. These methods are also discussed in this paper. Video Abstract.
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Affiliation(s)
- Ruozhu Yang
- Department of General Surgery, the Second Xiangya Hospital of Central South University, 139 Middle Renmin Road, Changsha, 410011, China
| | - Yi Han
- Department of General Surgery, the Second Xiangya Hospital of Central South University, 139 Middle Renmin Road, Changsha, 410011, China
| | - Xinyu Guan
- Department of General Surgery, the Second Xiangya Hospital of Central South University, 139 Middle Renmin Road, Changsha, 410011, China
| | - Yue Hong
- Department of General Surgery, the Second Xiangya Hospital of Central South University, 139 Middle Renmin Road, Changsha, 410011, China
| | - Jiahao Meng
- Department of General Surgery, the Second Xiangya Hospital of Central South University, 139 Middle Renmin Road, Changsha, 410011, China
| | - Shirong Ding
- Department of Oncology, the Second Xiangya Hospital of Central South University, 139 Middle Renmin Road, Changsha, 410011, China.
| | - Qian Long
- Department of General Surgery, the Second Xiangya Hospital of Central South University, 139 Middle Renmin Road, Changsha, 410011, China.
| | - Wenjun Yi
- Department of General Surgery, the Second Xiangya Hospital of Central South University, 139 Middle Renmin Road, Changsha, 410011, China.
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Chueaphromsri P, Kunhorm P, Phonchai R, Chaicharoenaudomrung N, Noisa P. Cordycepin Enhances SIRT1 Expression and Maintains Stemness of Human Mesenchymal Stem Cells. In Vivo 2023; 37:596-610. [PMID: 36881089 PMCID: PMC10026684 DOI: 10.21873/invivo.13118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 01/29/2023] [Accepted: 01/30/2023] [Indexed: 03/08/2023]
Abstract
BACKGROUND/AIM Mesenchymal stem cells (MSCs) have been employed for therapeutic applications of various degenerative diseases. However, the major concern is MSC aging during the in vitro cultivation. Thus, the approach to delay MSC aging was examined in this research by focusing on the expression of Sirtuin 1 (SIRT1), a key anti-aging marker. MATERIALS AND METHODS Cordycepin, a bioactive compound derived from Cordyceps militaris, was used to up-regulate SIRT1 and maintain stemness of MSCs. Upon treatment with cordycepin, MSCs were investigated for cell viability, doubling time, key gene/protein expression, galactosidase-associated senescence assay, relative telomere length, and telomerase expression. RESULTS Cordycepin significantly increased the expression of SIRT1 in MSCs by activating the adenosine monophosphate activated protein kinase (AMPK)-SIRT1 signalling pathway. Moreover, cordycepin maintained the stemness of MSCs by deacetylating SRY-box transcription factor 2 (SOX2) via SIRT1, and cordycepin delayed cellular senescence and aging of MSCs by enhancing autophagy, inhibiting the activity of senescence-associated-galactosidase, maintaining proliferation rate, and increasing telomere activity. CONCLUSION Cordycepin could be used to increase SIRT1 expression in MSCs for anti-aging applications.
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Affiliation(s)
- Phongsakorn Chueaphromsri
- Laboratory of Cell-Based Assays and Innovations, School of Biotechnology, Institute of Agricultural Technology, Suranaree University of Technology, Nakhon Ratchasima, Thailand
| | - Phongsakorn Kunhorm
- Laboratory of Cell-Based Assays and Innovations, School of Biotechnology, Institute of Agricultural Technology, Suranaree University of Technology, Nakhon Ratchasima, Thailand
| | - Ruchee Phonchai
- Laboratory of Cell-Based Assays and Innovations, School of Biotechnology, Institute of Agricultural Technology, Suranaree University of Technology, Nakhon Ratchasima, Thailand
| | - Nipha Chaicharoenaudomrung
- Laboratory of Cell-Based Assays and Innovations, School of Biotechnology, Institute of Agricultural Technology, Suranaree University of Technology, Nakhon Ratchasima, Thailand
| | - Parinya Noisa
- Laboratory of Cell-Based Assays and Innovations, School of Biotechnology, Institute of Agricultural Technology, Suranaree University of Technology, Nakhon Ratchasima, Thailand
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Ropio J, Prochazkova-Carlotti M, Batista R, Pestana A, Chebly A, Ferrer J, Idrissi Y, Cappellen D, Durães C, Boaventura P, Vinagre J, Azzi-Martin L, Poglio S, Cabeçadas J, Campos MA, Beylot-Barry M, Sobrinho-Simões M, Merlio JP, Soares P, Chevret E. Spotlight on hTERT Complex Regulation in Cutaneous T-Cell Lymphomas. Genes (Basel) 2023; 14:439. [PMID: 36833366 PMCID: PMC9956048 DOI: 10.3390/genes14020439] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 02/05/2023] [Accepted: 02/06/2023] [Indexed: 02/11/2023] Open
Abstract
As a major cancer hallmark, there is a sustained interest in understanding the telomerase contribution to carcinogenesis in order to therapeutically target this enzyme. This is particularly relevant in primary cutaneous T-cell lymphomas (CTCL), a malignancy showing telomerase dysregulation with few investigative data available. In CTCL, we examined the mechanisms involved in telomerase transcriptional activation and activity regulation. We analyzed 94 CTCL patients from a Franco-Portuguese cohort, as well as 8 cell lines, in comparison to 101 healthy controls. Our results showed that not only polymorphisms (SNPs) located at the promoter of human telomerase reverse transcriptase (hTERT) gene (rs2735940 and rs2853672) but also an SNP located within the coding region (rs2853676) could influence CTCL occurrence. Furthermore, our results sustained that the post-transcriptional regulation of hTERT contributes to CTCL lymphomagenesis. Indeed, CTCL cells present a different pattern of hTERT spliced transcripts distribution from the controls, mostly marked by an increase in the hTERT β+ variants proportion. This increase seems to be associated with CTCL development and progression. Through hTERT splicing transcriptome modulation with shRNAs, we observed that the decrease in the α-β+ transcript induced a decrease in the cell proliferation and tumorigenic capacities of T-MF cells in vitro. Taken together, our data highlight the major role of post-transcriptional mechanisms regulating telomerase non canonical functions in CTCL and suggest a new potential role for the α-β+ hTERT transcript variant.
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Affiliation(s)
- Joana Ropio
- BRIC (BoRdeaux Institute of onCology), UMR1312, INSERM, University of Bordeaux, 33000 Bordeaux, France
- Institute of Biomedical Sciences of Abel Salazar, Porto University, 4050-313 Porto, Portugal
- Faculty of Veterinary Medicine, Lusófona University, 1749-024 Lisbon, Portugal
| | | | - Rui Batista
- Institute for Research and Innovation in Health (I3S), Porto University, 4200-135 Porto, Portugal
- Institute of Molecular Pathology and Immunology of the University of Porto (IPATIMUP), Cancer Biology Group, Porto University, 4200-465 Porto, Portugal
- Faculty of Medicine, Porto University, 4200-319 Porto, Portugal
| | - Ana Pestana
- Institute for Research and Innovation in Health (I3S), Porto University, 4200-135 Porto, Portugal
- Institute of Molecular Pathology and Immunology of the University of Porto (IPATIMUP), Cancer Biology Group, Porto University, 4200-465 Porto, Portugal
- Faculty of Medicine, Porto University, 4200-319 Porto, Portugal
| | - Alain Chebly
- BRIC (BoRdeaux Institute of onCology), UMR1312, INSERM, University of Bordeaux, 33000 Bordeaux, France
- Medical Genetics Unit, Faculty of Medicine, Saint Joseph University, Beirut 1104 2020, Lebanon
- Higher Institute of Public Health, Saint Joseph University, Beirut 1104 2020, Lebanon
| | - Jacky Ferrer
- BRIC (BoRdeaux Institute of onCology), UMR1312, INSERM, University of Bordeaux, 33000 Bordeaux, France
| | - Yamina Idrissi
- BRIC (BoRdeaux Institute of onCology), UMR1312, INSERM, University of Bordeaux, 33000 Bordeaux, France
| | - David Cappellen
- BRIC (BoRdeaux Institute of onCology), UMR1312, INSERM, University of Bordeaux, 33000 Bordeaux, France
- Tumor Bank and Tumor Biology Laboratory, Bordeaux University Hospital, 33075 Bordeaux, France
| | - Cecília Durães
- Institute for Research and Innovation in Health (I3S), Porto University, 4200-135 Porto, Portugal
- Institute of Molecular Pathology and Immunology of the University of Porto (IPATIMUP), Cancer Biology Group, Porto University, 4200-465 Porto, Portugal
| | - Paula Boaventura
- Institute of Molecular Pathology and Immunology of the University of Porto (IPATIMUP), Cancer Biology Group, Porto University, 4200-465 Porto, Portugal
| | - João Vinagre
- Institute for Research and Innovation in Health (I3S), Porto University, 4200-135 Porto, Portugal
- Institute of Molecular Pathology and Immunology of the University of Porto (IPATIMUP), Cancer Biology Group, Porto University, 4200-465 Porto, Portugal
| | - Lamia Azzi-Martin
- BRIC (BoRdeaux Institute of onCology), UMR1312, INSERM, University of Bordeaux, 33000 Bordeaux, France
- UFR des Sciences Médicales, Bordeaux University, 33076 Bordeaux, France
| | - Sandrine Poglio
- BRIC (BoRdeaux Institute of onCology), UMR1312, INSERM, University of Bordeaux, 33000 Bordeaux, France
| | - José Cabeçadas
- Dermatology Departement, Instituto Português de Oncologia de Lisboa (IPO-L), 1099-023 Lisbon, Portugal
| | - Manuel António Campos
- Institute for Research and Innovation in Health (I3S), Porto University, 4200-135 Porto, Portugal
- Institute of Molecular Pathology and Immunology of the University of Porto (IPATIMUP), Cancer Biology Group, Porto University, 4200-465 Porto, Portugal
- Faculty of Medicine, Porto University, 4200-319 Porto, Portugal
- Centro Hospitalar Vila Nova de Gaia/Espinho, E.P.E., Dermatology Departement, 4434-502 Vila Nova de Gaia, Portugal
| | - Marie Beylot-Barry
- BRIC (BoRdeaux Institute of onCology), UMR1312, INSERM, University of Bordeaux, 33000 Bordeaux, France
- Dermatology Department, Bordeaux University Hospital, 33075 Bordeaux, France
| | - Manuel Sobrinho-Simões
- Institute for Research and Innovation in Health (I3S), Porto University, 4200-135 Porto, Portugal
- Institute of Molecular Pathology and Immunology of the University of Porto (IPATIMUP), Cancer Biology Group, Porto University, 4200-465 Porto, Portugal
- Faculty of Medicine, Porto University, 4200-319 Porto, Portugal
- Department of Pathology, Faculty of Medicine, Porto University, 4200-319 Porto, Portugal
| | - Jean-Philippe Merlio
- BRIC (BoRdeaux Institute of onCology), UMR1312, INSERM, University of Bordeaux, 33000 Bordeaux, France
- Tumor Bank and Tumor Biology Laboratory, Bordeaux University Hospital, 33075 Bordeaux, France
| | - Paula Soares
- Institute for Research and Innovation in Health (I3S), Porto University, 4200-135 Porto, Portugal
- Institute of Molecular Pathology and Immunology of the University of Porto (IPATIMUP), Cancer Biology Group, Porto University, 4200-465 Porto, Portugal
- Faculty of Medicine, Porto University, 4200-319 Porto, Portugal
- Department of Pathology, Faculty of Medicine, Porto University, 4200-319 Porto, Portugal
| | - Edith Chevret
- BRIC (BoRdeaux Institute of onCology), UMR1312, INSERM, University of Bordeaux, 33000 Bordeaux, France
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Ait-Aissa K, Norwood-Toro LE, Terwoord J, Young M, Paniagua LA, Hader SN, Hughes WE, Hockenberry JC, Beare JE, Linn J, Kohmoto T, Kim J, Betts DH, LeBlanc AJ, Gutterman DD, Beyer AM. Noncanonical Role of Telomerase in Regulation of Microvascular Redox Environment With Implications for Coronary Artery Disease. FUNCTION (OXFORD, ENGLAND) 2022; 3:zqac043. [PMID: 36168588 PMCID: PMC9508843 DOI: 10.1093/function/zqac043] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Revised: 08/05/2022] [Accepted: 08/11/2022] [Indexed: 01/28/2023]
Abstract
Telomerase reverse transcriptase (TERT) (catalytic subunit of telomerase) is linked to the development of coronary artery disease (CAD); however, whether the role of nuclear vs. mitchondrial actions of TERT is involved is not determined. Dominant-negative TERT splice variants contribute to decreased mitochondrial integrity and promote elevated reactive oxygen species production. We hypothesize that a decrease in mitochondrial TERT would increase mtDNA damage, promoting a pro-oxidative redox environment. The goal of this study is to define whether mitochondrial TERT is sufficient to maintain nitric oxide as the underlying mechanism of flow-mediated dilation by preserving mtDNA integrity.Immunoblots and quantitative polymerase chain reaction were used to show elevated levels of splice variants α- and β-deletion TERT tissue from subjects with and without CAD. Genetic, pharmacological, and molecular tools were used to manipulate TERT localization. Isolated vessel preparations and fluorescence-based quantification of mtH2O2 and NO showed that reduction of TERT in the nucleus increased flow induced NO and decreased mtH2O2 levels, while prevention of mitochondrial import of TERT augmented pathological effects. Further elevated mtDNA damage was observed in tissue from subjects with CAD and initiation of mtDNA repair mechanisms was sufficient to restore NO-mediated dilation in vessels from patients with CAD. The work presented is the first evidence that catalytically active mitochondrial TERT, independent of its nuclear functions, plays a critical physiological role in preserving NO-mediated vasodilation and the balance of mitochondrial to nuclear TERT is fundamentally altered in states of human disease that are driven by increased expression of dominant negative splice variants.
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Affiliation(s)
- K Ait-Aissa
- Department of Internal Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - L E Norwood-Toro
- Department of Medicine, Medical College of Wisconsin, Milwaukee, WI 53226, USA,Cardiovascular Center, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - J Terwoord
- Department of Medicine, Medical College of Wisconsin, Milwaukee, WI 53226, USA,Cardiovascular Center, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - M Young
- Department of Medicine, Medical College of Wisconsin, Milwaukee, WI 53226, USA,Cardiovascular Center, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - L A Paniagua
- Department of Medicine, Medical College of Wisconsin, Milwaukee, WI 53226, USA,Cardiovascular Innovation Institute, University of Louisville, Louisville, KY 40292, USA
| | - S N Hader
- Department of Medicine, Medical College of Wisconsin, Milwaukee, WI 53226, USA,Cardiovascular Center, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - W E Hughes
- Department of Internal Medicine, University of Iowa, Iowa City, IA 52242, USA,Cardiovascular Center, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - J C Hockenberry
- Department of Medicine, Medical College of Wisconsin, Milwaukee, WI 53226, USA,Cardiovascular Center, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - J E Beare
- Cardiovascular Innovation Institute, University of Louisville, Louisville, KY 40292, USA,Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, KY 40292, USA
| | - J Linn
- Department of Medicine, Medical College of Wisconsin, Milwaukee, WI 53226, USA,Cardiovascular Center, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - T Kohmoto
- Department of Surgery, Division of Cardiothoracic Surgery, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - J Kim
- Department of Physiology and Pharmacology, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, ON N6A 5C1, Canada
| | - D H Betts
- Department of Physiology and Pharmacology, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, ON N6A 5C1, Canada
| | - A J LeBlanc
- Cardiovascular Innovation Institute, University of Louisville, Louisville, KY 40292, USA,Department of Cardiovascular and Thoracic Surgery, School of Medicine, University of Louisville, Louisville, KY 40292, USA
| | - D D Gutterman
- Department of Medicine, Medical College of Wisconsin, Milwaukee, WI 53226, USA,Cardiovascular Center, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - A M Beyer
- Address correspondence to A.M.B. (e-mail: )
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8
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Taheri M, Ghafouri-Fard S, Najafi S, Kallenbach J, Keramatfar E, Atri Roozbahani G, Heidari Horestani M, Hussen BM, Baniahmad A. Hormonal regulation of telomerase activity and hTERT expression in steroid-regulated tissues and cancer. Cancer Cell Int 2022; 22:258. [PMID: 35974340 PMCID: PMC9380309 DOI: 10.1186/s12935-022-02678-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Accepted: 08/05/2022] [Indexed: 11/10/2022] Open
Abstract
Naturally, in somatic cells chromosome ends (telomeres) shorten during each cell division. This process ensures to limit proliferation of somatic cells to avoid malignant proliferation; however, it leads to proliferative senescence. Telomerase contains the reverse transcriptase TERT, which together with the TERC component, is responsible for protection of genome integrity by preventing shortening of telomeres through adding repetitive sequences. In addition, telomerase has non-telomeric function and supports growth factor independent growth. Unlike somatic cells, telomerase is detectable in stem cells, germ line cells, and cancer cells to support self-renewal and expansion. Elevated telomerase activity is reported in almost all of human cancers. Increased expression of hTERT gene or its reactivation is required for limitless cellular proliferation in immortal malignant cells. In hormonally regulated tissues as well as in prostate, breast and endometrial cancers, telomerase activity and hTERT expression are under control of steroid sex hormones and growth factors. Also, a number of hormones and growth factors are known to play a role in the carcinogenesis via regulation of hTERT levels or telomerase activity. Understanding the role of hormones in interaction with telomerase may help finding therapeutical targets for anticancer strategies. In this review, we outline the roles and functions of several steroid hormones and growth factors in telomerase regulation, particularly in hormone regulated cancers such as prostate, breast and endometrial cancer.
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Affiliation(s)
- Mohammad Taheri
- Urology and Nephrology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran.,Institute of Human Genetics, Jena University Hospital, 07740, Jena, Germany
| | - Soudeh Ghafouri-Fard
- Department of Medical Genetics, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Sajad Najafi
- Department of Medical Biotechnology, School of Advanced Technologies in Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Julia Kallenbach
- Institute of Human Genetics, Jena University Hospital, 07740, Jena, Germany
| | - Elmira Keramatfar
- Institute of Human Genetics, Jena University Hospital, 07740, Jena, Germany
| | | | | | - Bashdar Mahmud Hussen
- Department of Pharmacognosy, College of Pharmacy, Hawler Medical University, Kurdistan Region, Erbil, Iraq.,Center of Research and Strategic Studies, Lebanese French University, Erbil, Kurdistan Region, Iraq
| | - Aria Baniahmad
- Institute of Human Genetics, Jena University Hospital, 07740, Jena, Germany.
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9
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Gurnari C, Pagliuca S, Visconte V. Alternative Splicing in Myeloid Malignancies. Biomedicines 2021; 9:biomedicines9121844. [PMID: 34944660 PMCID: PMC8698609 DOI: 10.3390/biomedicines9121844] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Revised: 11/28/2021] [Accepted: 12/03/2021] [Indexed: 01/02/2023] Open
Abstract
Alternative RNA splicing (AS) is an essential physiologic function that diversifies the human proteome. AS also has a crucial role during cellular development. In fact, perturbations in RNA-splicing have been implicated in the development of several cancers, including myeloid malignancies. Splicing dysfunction can be independent of genetic lesions or appear as a direct consequence of mutations in components of the RNA-splicing machinery, such as in the case of mutations occurring in splicing factor genes (i.e., SF3B1, SRSF2, U2AF1) and their regulators. In addition, cancer cells exhibit marked gene expression alterations, including different usage of AS isoforms, possibly causing tissue-specific effects and perturbations of downstream pathways. This review summarizes several modalities leading to splicing diversity in myeloid malignancies.
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Affiliation(s)
- Carmelo Gurnari
- Department of Translational Hematology and Oncology Research, Taussig Cancer Institute, Cleveland Clinic, Cleveland, OH 44195, USA; (C.G.); (S.P.)
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, 00133 Rome, Italy
| | - Simona Pagliuca
- Department of Translational Hematology and Oncology Research, Taussig Cancer Institute, Cleveland Clinic, Cleveland, OH 44195, USA; (C.G.); (S.P.)
| | - Valeria Visconte
- Department of Translational Hematology and Oncology Research, Taussig Cancer Institute, Cleveland Clinic, Cleveland, OH 44195, USA; (C.G.); (S.P.)
- Correspondence:
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10
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Plyasova AA, Zhdanov DD. Alternative Splicing of Human Telomerase Reverse Transcriptase (hTERT) and Its Implications in Physiological and Pathological Processes. Biomedicines 2021; 9:526. [PMID: 34065134 PMCID: PMC8150890 DOI: 10.3390/biomedicines9050526] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 05/03/2021] [Accepted: 05/05/2021] [Indexed: 12/24/2022] Open
Abstract
Alternative splicing (AS) of human telomerase catalytic subunit (hTERT, human telomerase reverse transcriptase) pre-mRNA strongly regulates telomerase activity. Several proteins can regulate AS in a cell type-specific manner and determine the functions of cells. In addition to being involved in telomerase activity regulation, AS provides cells with different splice variants that may have alternative biological activities. The modulation of telomerase activity through the induction of hTERT AS is involved in the development of different cancer types and embryos, and the differentiation of stem cells. Regulatory T cells may suppress the proliferation of target human and murine T and B lymphocytes and NK cells in a contact-independent manner involving activation of TERT AS. This review focuses on the mechanism of regulation of hTERT pre-mRNA AS and the involvement of splice variants in physiological and pathological processes.
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Affiliation(s)
| | - Dmitry D. Zhdanov
- Institute of Biomedical Chemistry, Pogodinskaya st 10/8, 119121 Moscow, Russia;
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11
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Subasri M, Shooshtari P, Watson AJ, Betts DH. Analysis of TERT Isoforms across TCGA, GTEx and CCLE Datasets. Cancers (Basel) 2021; 13:cancers13081853. [PMID: 33924498 PMCID: PMC8070023 DOI: 10.3390/cancers13081853] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 04/01/2021] [Accepted: 04/08/2021] [Indexed: 12/14/2022] Open
Abstract
Reactivation of the multi-subunit ribonucleoprotein telomerase is the primary telomere maintenance mechanism in cancer, but it is rate-limited by the enzymatic component, telomerase reverse transcriptase (TERT). While regulatory in nature, TERT alternative splice variant/isoform regulation and functions are not fully elucidated and are further complicated by their highly diverse expression and nature. Our primary objective was to characterize TERT isoform expression across 7887 neoplastic and 2099 normal tissue samples using The Cancer Genome Atlas (TCGA) and the Genotype-Tissue Expression Project (GTEx), respectively. We confirmed the global overexpression and splicing shift towards full-length TERT in neoplastic tissue. Stratifying by tissue type we found uncharacteristic TERT expression in normal brain tissue subtypes. Stratifying by tumor-specific subtypes, we detailed TERT expression differences potentially regulated by subtype-specific molecular characteristics. Focusing on β-deletion splicing regulation, we found the NOVA1 trans-acting factor to mediate alternative splicing in a cancer-dependent manner. Of relevance to future tissue-specific studies, we clustered cancer cell lines with tumors from related origin based on TERT isoform expression patterns. Taken together, our work has reinforced the need for tissue and tumour-specific TERT investigations, provided avenues to do so, and brought to light the current technical limitations of bioinformatic analyses of TERT isoform expression.
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Affiliation(s)
- Mathushan Subasri
- Department of Physiology and Pharmacology, The University of Western Ontario, London, ON N6A 5C1, Canada; (M.S.); (A.J.W.)
| | - Parisa Shooshtari
- Ontario Institute for Cancer Research, Toronto, ON M5G 0A3, Canada;
- Department of Pathology and Laboratory Medicine, The University of Western Ontario, London, ON N6A 5C1, Canada
- Department of Computer Science, The University of Western Ontario, London, ON N6A 5C1, Canada
- The Children’s Health Research Institute—Lawson Health Research Institute, London, ON N6C 2R5, Canada
| | - Andrew J. Watson
- Department of Physiology and Pharmacology, The University of Western Ontario, London, ON N6A 5C1, Canada; (M.S.); (A.J.W.)
- The Children’s Health Research Institute—Lawson Health Research Institute, London, ON N6C 2R5, Canada
- Department of Obstetrics and Gynaecology, The University of Western Ontario, London, ON N6A 5C1, Canada
| | - Dean H. Betts
- Department of Physiology and Pharmacology, The University of Western Ontario, London, ON N6A 5C1, Canada; (M.S.); (A.J.W.)
- The Children’s Health Research Institute—Lawson Health Research Institute, London, ON N6C 2R5, Canada
- Department of Obstetrics and Gynaecology, The University of Western Ontario, London, ON N6A 5C1, Canada
- Correspondence: ; Tel.: +1-519-661-2111 (ext. 83786)
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12
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Dogan F, Forsyth NR. Telomerase Regulation: A Role for Epigenetics. Cancers (Basel) 2021; 13:cancers13061213. [PMID: 33802026 PMCID: PMC8000866 DOI: 10.3390/cancers13061213] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 03/05/2021] [Accepted: 03/07/2021] [Indexed: 12/11/2022] Open
Abstract
Simple Summary Maintenance of telomeres is a fundamental step in human carcinogenesis and is primarily regulated by telomerase and the human telomerase reverse transcriptase gene (TERT). Improved understanding of the transcriptional control of this gene may provide potential therapeutic targets. Epigenetic modifications are a prominent mechanism to control telomerase activity and regulation of the TERT gene. TERT-targeting miRNAs have been widely studied and their function explained through pre-clinical in vivo model-based validation studies. Further, histone deacetylase inhibitors are now in pre and early clinical trials with significant clinical success. Importantly, TERT downregulation through epigenetic modifications including TERT promoter methylation, histone deacetylase inhibitors, and miRNA activity might contribute to clinical study design. This review provides an overview of the epigenetic mechanisms involved in the regulation of TERT expression and telomerase activity. Abstract Telomerase was first described by Greider and Blackburn in 1984, a discovery ultimately recognized by the Nobel Prize committee in 2009. The three decades following on from its discovery have been accompanied by an increased understanding of the fundamental mechanisms of telomerase activity, and its role in telomere biology. Telomerase has a clearly defined role in telomere length maintenance and an established influence on DNA replication, differentiation, survival, development, apoptosis, tumorigenesis, and a further role in therapeutic resistance in human stem and cancer cells including those of breast and cervical origin. TERT encodes the catalytic subunit and rate-limiting factor for telomerase enzyme activity. The mechanisms of activation or silencing of TERT remain open to debate across somatic, cancer, and stem cells. Promoter mutations upstream of TERT may promote dysregulated telomerase activation in tumour cells but additional factors including epigenetic, transcriptional and posttranscriptional modifications also have a role to play. Previous systematic analysis indicated methylation and mutation of the TERT promoter in 53% and 31%, respectively, of TERT expressing cancer cell lines supporting the concept of a key role for epigenetic alteration associated with TERT dysregulation and cellular transformation. Epigenetic regulators including DNA methylation, histone modification, and non-coding RNAs are now emerging as drivers in the regulation of telomeres and telomerase activity. Epigenetic regulation may be responsible for reversible silencing of TERT in several biological processes including development and differentiation, and increased TERT expression in cancers. Understanding the epigenetic mechanisms behind telomerase regulation holds important prospects for cancer treatment, diagnosis and prognosis. This review will focus on the role of epigenetics in telomerase regulation.
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Affiliation(s)
- Fatma Dogan
- The Guy Hilton Research Laboratories, School of Pharmacy and Bioengineering, Faculty of Medicine and Health Sciences, Keele University, Stoke on Trent ST4 7QB, UK;
| | - Nicholas R. Forsyth
- The Guy Hilton Research Laboratories, School of Pharmacy and Bioengineering, Faculty of Medicine and Health Sciences, Keele University, Stoke on Trent ST4 7QB, UK;
- School of Medicine, Tongji University, Shanghai 200092, China
- Correspondence:
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13
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Yegorov YE, Poznyak AV, Nikiforov NG, Starodubova AV, Orekhov AN. Role of Telomeres Shortening in Atherogenesis: An Overview. Cells 2021; 10:395. [PMID: 33671887 PMCID: PMC7918954 DOI: 10.3390/cells10020395] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Revised: 02/07/2021] [Accepted: 02/13/2021] [Indexed: 02/07/2023] Open
Abstract
It is known that the shortening of the telomeres leads to cell senescence, accompanied by acquiring of pro-inflammatory phenotype. The expression of telomerase can elongate telomeres and resist the onset of senescence. The initiation of atherosclerosis is believed to be associated with local senescence of the endothelial cells of the arteries in places with either low or multidirectional oscillatory wall shear stress. The process of regeneration of the artery surface that has begun does not lead to success for several reasons. Atherosclerotic plaques are formed, which, when developed, lead to fatal consequences, which are the leading causes of death in the modern world. The pronounced age dependence of the manifestations of atherosclerosis pushes scientists to try to link the development of atherosclerosis with telomere length. The study of the role of telomere shortening in atherosclerosis is mainly limited to measuring the telomeres of blood cells, and only in rare cases (surgery or post-mortem examination) are the telomeres of local cells available for measurement. The review discusses the basic issues of cellular aging and the interpretation of telomere measurement data in atherosclerosis, as well as the prospects for the prevention and possible treatment of atherosclerosis.
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Affiliation(s)
- Yegor E. Yegorov
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow 119991, Russia;
| | - Anastasia V. Poznyak
- Institute for Atherosclerosis Research, Skolkovo Innovative Center, Moscow 121609, Russia
| | - Nikita G. Nikiforov
- Laboratory of Angiopathology, Institute of General Pathology and Pathophysiology, Moscow 125315, Russia;
- National Medical Research Center of Cardiology, Institute of Experimental Cardiology, Moscow 121552, Russia
- Institute of Gene Biology, Center of Collective Usage, Moscow 119334, Russia
| | - Antonina V. Starodubova
- Federal Research Centre for Nutrition, Biotechnology and Food Safety, Moscow 109240, Russia;
- Pirogov Russian National Research Medical University, Moscow 117997, Russia
| | - Alexander N. Orekhov
- Institute for Atherosclerosis Research, Skolkovo Innovative Center, Moscow 121609, Russia
- Laboratory of Angiopathology, Institute of General Pathology and Pathophysiology, Moscow 125315, Russia;
- Institute of Human Morphology, Moscow 117418, Russia
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Abstract
Objective Alternative splicing can generate various structural and functional protein isoforms. Recently, accumulating evidence shows a relationship between alternative splicing and cancer. Cancer is a complex and chronic disease that involves malignant transformation. In this review, we consider alternative splicing events in relation to the hallmarks of cancer cells, and discuss current therapies to treat cancer-related to alternative splicing. Data sources Data cited in this article are from the PubMed and Embase database, primarily focusing on research published from 2000 to 2018. Study selection Articles were selected with the search terms “alternative splicing,” “cancer cell,” “tumor microenvironment,” and “therapy.” Results Alternative splicing plays an important role in tumorigenesis, development, and escape from cell death. Taking this trait of cancer cells into consideration will allow more definite diagnoses of cancer, and allow the development of more effective medicines to intervene in cancer that could focus on controlling alternative splicing or competitively binding to the final products. Conclusions Alternative splicing is common in cancer cells. Consideration of alternative splicing may allow different strategies for cancer therapy or the identification of novel biomarkers for cancer diagnosis.
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Dosset M, Castro A, Carter H, Zanetti M. Telomerase and CD4 T Cell Immunity in Cancer. Cancers (Basel) 2020; 12:cancers12061687. [PMID: 32630460 PMCID: PMC7352225 DOI: 10.3390/cancers12061687] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 06/19/2020] [Accepted: 06/22/2020] [Indexed: 12/13/2022] Open
Abstract
Telomerase reverse transcriptase (TERT) is a conserved self-tumor antigen which is overexpressed in most tumors and plays a critical role in tumor formation and progression. As such, TERT is an antigen of great relevance to develop widely applicable immunotherapies. CD4 T cells play a major role in the anti-cancer response alone or with other effector cells such as CD8 T cells and NK cells. To date, efforts have been made to identify TERT peptides capable of stimulating CD4 T cells that are also able to bind diverse MHC-II alleles to ease immune status monitoring and immunotherapies. Here, we review the current status of TERT biology, TERT/MHC-II immunobiology, and past and current vaccine clinical trials. We propose that monitoring CD4 T cell immunity against TERT is a simple and direct way to assess immune surveillance in cancer patients and a new way to predict the response to immune checkpoint inhibitors (ICPi). Finally, we present the initial results of a systematic discovery of TERT peptides able to bind the most common HLA Class II alleles worldwide and show that the repertoire of MHC-II TERT peptides is wider than currently appreciated.
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Affiliation(s)
- Magalie Dosset
- The Laboratory of Immunology, Department of Medicine and Moores Cancer Center, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093-081, USA;
| | - Andrea Castro
- Division of Medical Genetics, Department of Medicine and Bioinformatics and Systems Biology Program, University of California San Diego, La Jolla, CA 92093, USA; (A.C.); (H.C.)
- Health Science, Department of Biomedical Informatics, School of Medicine, University of California San Diego, La Jolla, CA 92093, USA
| | - Hannah Carter
- Division of Medical Genetics, Department of Medicine and Bioinformatics and Systems Biology Program, University of California San Diego, La Jolla, CA 92093, USA; (A.C.); (H.C.)
| | - Maurizio Zanetti
- The Laboratory of Immunology, Department of Medicine and Moores Cancer Center, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093-081, USA;
- Correspondence:
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Wang S, Yan WW, He M, Wei D, Long ZJ, Tao YM. Aloe emodin inhibits telomerase activity in breast cancer cells: transcriptional and enzymological mechanism. Pharmacol Rep 2020; 72:1383-1396. [PMID: 32207090 DOI: 10.1007/s43440-020-00062-w] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2019] [Revised: 01/10/2020] [Accepted: 01/30/2020] [Indexed: 12/31/2022]
Abstract
BACKGROUND Telomerase plays an essential role in cancer cell proliferation. In this study, we investigated inhibition mechanism of aloe emodin (AE) on three different types of breast cancer cell lines, MDA-MB-453, MDA-MB-231 and MCF-7. METHODS The cells were treated with different concentrations of AE. Relative length of telomere and human telomerase reverse-transcriptase (hTERT) mRNA level was analyzed by quantitative PCR (qPCR). Protein level was assayed by Western blot. Sodium bisulfite methylation sequencing was performed to assess the methylation status of gene promoter. Enzymology kinetics was applied to reveal the interaction between AE and telomerase. Ultraviolet-visible titration and fluorescence resonance energy transfer (FRET) melting experiment were carried out to study the interaction between AE and telomeric DNA. RESULTS Continuous AE exposure of these cells for 48 h results in shortening of telomeres and inhibition of telomerase. The transcription of hTERT was repressed by activation of E2F1 and inactivation of c-myc proteins. Significant demethylation of CpG islands in hTERT gene promoter was observed in MDA-MB-453 and MCF-7 cells. AE competed with dNTP for occupation of the enzyme active site. AE was a telomeric G-quadruplex structure stabilizer as indicated by titration test and FRET experiments. CONCLUSIONS AE was a competitive inhibitor of telomerase and a G-quadruplex structure stabilizer. AE decreased the transcription of hTERT gene in the three breast cancer cell lines via up-regulation E2F1 and down-regulation c-myc expressions. The suppressed transcription was also related to the demethylation of the gene promoter.
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Affiliation(s)
- Song Wang
- College of Biotechnology, Guilin Medical University, Guilin, 541004, People's Republic of China.,Peking University Shenzhen Hospital, Shenzhen, 518035, People's Republic of China
| | - Wen-Wen Yan
- College of Biotechnology, Guilin Medical University, Guilin, 541004, People's Republic of China
| | - Min He
- College of Biotechnology, Guilin Medical University, Guilin, 541004, People's Republic of China
| | - Dan Wei
- College of Biotechnology, Guilin Medical University, Guilin, 541004, People's Republic of China
| | - Zu-Ji Long
- College of Biotechnology, Guilin Medical University, Guilin, 541004, People's Republic of China
| | - Yi-Ming Tao
- College of Biotechnology, Guilin Medical University, Guilin, 541004, People's Republic of China.
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Smith-Sonneborn J. Telomerase Biology Associations Offer Keys to Cancer and Aging Therapeutics. Curr Aging Sci 2020; 13:11-21. [PMID: 31544708 PMCID: PMC7403649 DOI: 10.2174/1874609812666190620124324] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Revised: 05/07/2019] [Accepted: 05/24/2019] [Indexed: 02/07/2023]
Abstract
BACKGROUND Although telomerase has potential for age-related disease intervention, the overexpression of telomerase in about 90% of cancers, and in HIV virus reservoirs, cautions against se in anti-aging telomerase therapeutics. While multiple reviews document the canonical function of telomerase for maintenance of telomeres, as well as an increasing numbers of reviews that reveal new non-canonical functions of telomerase, there was no systematic review that focuses on the array of associates of the subunit of Telomerase Reverse transcriptase protein (TERT) as pieces of the puzzle to assemble a picture of the how specific TERT complexes uniquely impact aging and age-related diseases and more can be expected. METHODS A structured search of bibliographic data on TERT complexes was undertaken using databases from the National Center for Biotechnology Information Pubmed with extensive access to biomedical and genomic information in order to obtain a unique documented and cited overview of TERT complexes that may uniquely impact aging and age-related diseases. RESULTS The TERT associations include proper folding, intracellular TERT transport, metabolism, mitochondrial ROS (Reactive Oxygen Species) regulation, inflammation, cell division, cell death, and gene expression, in addition to the well-known telomere maintenance. While increase of cell cycle inhibitors promote aging, in cancer, the cell cycle check-point regulators are ambushed in favor of cell proliferation, while cytoplasmic TERT protects a cell cycle inhibitor in oxidative stress. The oncogene cMyc regulates gene expression for overexpression of TERT, and reduction of cell cycle inhibitors-the perfect storm for cancer promotion. TERT binds with the oncogene RMRP RNA, and TERT-RMRP function can regulate levels of that oncogene RNA, and TERT in a TBN complex can regulate heterochromatin. Telomerase benefit and novel function in neurology and cardiology studies open new anti- aging hope. GV1001, a 16 amino acid peptide of TERT that associates with Heat Shock Proteins (HSP's), bypasses the cell membrane with remarkable anti disease potential. CONCLUSIONS TERT "associates" are anti-cancer targets for downregulation, but upregulation in antiaging therapy. The overview revealed that unique TERT associations that impact all seven pillars of aging identified by the Trans-NIH Geroscience Initiative that influence aging and urge research for appropriate targeted telomerase supplements/ stimulation, and inclusion in National Institute on Aging Intervention Testing Program. The preference for use of available "smart drugs", targeted to only cancer, not off-target anti- aging telomerase is implied by the multiplicity of TERT associates functions.
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Affiliation(s)
- Joan Smith-Sonneborn
- Department Zoology and Physiology, University of Wyoming, Laramie, Wyoming, WY, USA
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18
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Xie Z, Wu H, Dang Y, Chen G. Role of alternative splicing signatures in the prognosis of glioblastoma. Cancer Med 2019; 8:7623-7636. [PMID: 31674730 PMCID: PMC6912032 DOI: 10.1002/cam4.2666] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2019] [Revised: 10/08/2019] [Accepted: 10/15/2019] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Increasing evidence has validated the crucial role of alternative splicing (AS) in tumors. However, comprehensive investigations on the entirety of AS and their clinical value in glioblastoma (GBM) are lacking. METHODS The AS profiles and clinical survival data related to GBM were obtained from The Cancer Genome Atlas database. Univariate and multivariate Cox regression analyses were performed to identify survival-associated AS events. A risk score was calculated, and prognostic signatures were constructed using seven different types of independent prognostic AS events, respectively. The Kaplan-Meier estimator was used to display the survival of GBM patients. The receiver operating characteristic curve was applied to compare the predictive efficacy of each prognostic signature. Enrichment analysis and protein interactive networks were conducted using the gene symbols of the AS events to investigate important processes in GBM. A splicing network between splicing factors and AS events was constructed to display the potential regulatory mechanism in GBM. RESULTS A total of 2355 survival-associated AS events were identified. The splicing prognostic model revealed that patients in the high-risk group have worse survival rates than those in the low-risk group. The predictive efficacy of each prognostic model showed satisfactory performance; among these, the Alternate Terminator (AT) model showed the best performance at an area under the curve (AUC) of 0.906. Enrichment analysis uncovered that autophagy was the most enriched process of prognostic AS gene symbols in GBM. The protein network revealed that UBC, VHL, KCTD7, FBXL19, RNF7, and UBE2N were the core genes in GBM. The splicing network showed complex regulatory correlations, among which ELAVL2 and SYNE1_AT_78181 were the most correlated (r = -.506). CONCLUSIONS Applying the prognostic signatures constructed by independent AS events shows promise for predicting the survival of GBM patients. A splicing regulatory network might be the potential splicing mechanism in GBM.
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Affiliation(s)
- Zu‐cheng Xie
- Department of PathologyThe First Affiliated Hospital of Guangxi Medical UniversityNanningGuangxi Zhuang Autonomous RegionP. R. China
| | - Hua‐yu Wu
- Department of Cell Biology and GeneticsSchool of Pre‐clinical MedicineGuangxi Medical UniversityNanningGuangxi Zhuang Autonomous RegionP. R. China
| | - Yi‐wu Dang
- Department of PathologyThe First Affiliated Hospital of Guangxi Medical UniversityNanningGuangxi Zhuang Autonomous RegionP. R. China
| | - Gang Chen
- Department of PathologyThe First Affiliated Hospital of Guangxi Medical UniversityNanningGuangxi Zhuang Autonomous RegionP. R. China
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Insights into Telomerase/hTERT Alternative Splicing Regulation Using Bioinformatics and Network Analysis in Cancer. Cancers (Basel) 2019; 11:cancers11050666. [PMID: 31091669 PMCID: PMC6562651 DOI: 10.3390/cancers11050666] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2019] [Revised: 05/10/2019] [Accepted: 05/13/2019] [Indexed: 01/08/2023] Open
Abstract
The reactivation of telomerase in cancer cells remains incompletely understood. The catalytic component of telomerase, hTERT, is thought to be the limiting component in cancer cells for the formation of active enzymes. hTERT gene expression is regulated at several levels including chromatin, DNA methylation, transcription factors, and RNA processing events. Of these regulatory events, RNA processing has received little attention until recently. RNA processing and alternative splicing regulation have been explored to understand how hTERT is regulated in cancer cells. The cis- and trans-acting factors that regulate the alternative splicing choice of hTERT in the reverse transcriptase domain have been investigated. Further, it was discovered that the splicing factors that promote the production of full-length hTERT were also involved in cancer cell growth and survival. The goals are to review telomerase regulation via alternative splicing and the function of hTERT splicing variants and to point out how bioinformatics approaches are leading the way in elucidating the networks that regulate hTERT splicing choice and ultimately cancer growth.
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20
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Wang F, Cheng Y, Zhang C, Chang G, Geng X. A novel antisense oligonucleotide anchored on the intronic splicing enhancer of hTERT pre-mRNA inhibits telomerase activity and induces apoptosis in glioma cells. J Neurooncol 2019; 143:57-68. [PMID: 30887243 DOI: 10.1007/s11060-019-03150-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2018] [Accepted: 03/11/2019] [Indexed: 12/15/2022]
Abstract
INTRODUCTION Alternative splicing of hTERT pre-mRNA is an important step in the regulation of telomerase activity, but the regulation mechanisms and functions remain unclear. METHODS RT-PCR analysis was used to detect hTERT splicing in glioma cell lines and brain tissues. TRAP assay was used to detect the telomerase activity. Then, we designed and synthesized 2'-O-methyl-RNA phosphorothioate AONs and transfected them into glioma cells to detect the changes in telomerase activity. MTT assay, plate colony formation assay, western blotting and Annexin V/PI assay were used to detect cell proliferation and apoptosis. At last, bioinformatics analyses were used to predict the expression and function of splicing protein SRSF2 in gliomas. RESULTS hTERT splicing occurs both in glioma cell lines and glioma patients' tissues. The telomerase activity was related to the expression level of the full-length hTERT, rather than the total hTERT transcript level. AON-Ex726 was complementary to the sequence of the intronic splicing enhancer (ISE) in intron six, and significantly altered the splicing pattern of hTERT pre-mRNA, reducing the expression level of the full-length hTERT mRNA and increasing the expression level of the -β hTERT mRNA. After transfection with AON-Ex726, the level of apoptosis was increased, while telomerase activity and cell proliferation were significantly decreased. By bioinformatic predictions, we found the AON-Ex726 anchoring sequence in ISE overlaps the binding site of SRSF2 protein, which is up-regulated during the development of gliomas. CONCLUSIONS Our findings provided new targets and important clues for the gene therapy of gliomas by regulating the alternative splicing pattern of hTERT pre-mRNA.
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Affiliation(s)
- Fei Wang
- Department of Neurology, General Hospital, Tianjin Medical University, Tianjin, 300052, China
| | - Yajing Cheng
- Department of Neurology, General Hospital, Tianjin Medical University, Tianjin, 300052, China
| | - Chi Zhang
- Department of Neurology, General Hospital, Tianjin Medical University, Tianjin, 300052, China
| | - Guangming Chang
- Department of Clinical Laboratory, General Hospital, Tianjin Medical University, Tianjin, 300052, China
| | - Xin Geng
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Key Laboratory of Immune Microenvironment and Disease, Ministry of Education, Tianjin Medical University, 22nd Qixiangtai Road, Tianjin, 300070, China.
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Shishkin SS, Kovalev LI, Pashintseva NV, Kovaleva MA, Lisitskaya K. Heterogeneous Nuclear Ribonucleoproteins Involved in the Functioning of Telomeres in Malignant Cells. Int J Mol Sci 2019; 20:ijms20030745. [PMID: 30744200 PMCID: PMC6387250 DOI: 10.3390/ijms20030745] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Revised: 01/31/2019] [Accepted: 02/04/2019] [Indexed: 12/12/2022] Open
Abstract
Heterogeneous nuclear ribonucleoproteins (hnRNPs) are structurally and functionally distinct proteins containing specific domains and motifs that enable the proteins to bind certain nucleotide sequences, particularly those found in human telomeres. In human malignant cells (HMCs), hnRNP-A1-the most studied hnRNP-is an abundant multifunctional protein that interacts with telomeric DNA and affects telomerase function. In addition, it is believed that other hnRNPs in HMCs may also be involved in the maintenance of telomere length. Accordingly, these proteins are considered possible participants in the processes associated with HMC immortalization. In our review, we discuss the results of studies on different hnRNPs that may be crucial to solving molecular oncological problems and relevant to further investigations of these proteins in HMCs.
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Affiliation(s)
- Sergey S Shishkin
- Laboratory of Biomedical Research, Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, Leninsky Prospekt, 33, bld. 2, 119071 Moscow, Russia.
| | - Leonid I Kovalev
- Laboratory of Biomedical Research, Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, Leninsky Prospekt, 33, bld. 2, 119071 Moscow, Russia.
| | - Natalya V Pashintseva
- Laboratory of Biomedical Research, Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, Leninsky Prospekt, 33, bld. 2, 119071 Moscow, Russia.
| | - Marina A Kovaleva
- Laboratory of Biomedical Research, Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, Leninsky Prospekt, 33, bld. 2, 119071 Moscow, Russia.
| | - Ksenia Lisitskaya
- Laboratory of Biomedical Research, Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, Leninsky Prospekt, 33, bld. 2, 119071 Moscow, Russia.
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22
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Okamoto K, Seimiya H. Revisiting Telomere Shortening in Cancer. Cells 2019; 8:cells8020107. [PMID: 30709063 PMCID: PMC6406355 DOI: 10.3390/cells8020107] [Citation(s) in RCA: 68] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2018] [Revised: 01/28/2019] [Accepted: 01/28/2019] [Indexed: 12/21/2022] Open
Abstract
Telomeres, the protective structures of chromosome ends are gradually shortened by each cell division, eventually leading to senescence or apoptosis. Cancer cells maintain the telomere length for unlimited growth by telomerase reactivation or a recombination-based mechanism. Recent genome-wide analyses have unveiled genetic and epigenetic alterations of the telomere maintenance machinery in cancer. While telomerase inhibition reveals that longer telomeres are more advantageous for cell survival, cancer cells often have paradoxically shorter telomeres compared with those found in the normal tissues. In this review, we summarize the latest knowledge about telomere length alterations in cancer and revisit its rationality. Finally, we discuss the potential utility of telomere length as a prognostic biomarker.
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Affiliation(s)
- Keiji Okamoto
- Division of Molecular Biotherapy, Cancer Chemotherapy Center, Japanese Foundation for Cancer Research, Koto-ku, Tokyo 135-8550, Japan.
| | - Hiroyuki Seimiya
- Division of Molecular Biotherapy, Cancer Chemotherapy Center, Japanese Foundation for Cancer Research, Koto-ku, Tokyo 135-8550, Japan.
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23
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Romaniuk A, Paszel-Jaworska A, Totoń E, Lisiak N, Hołysz H, Królak A, Grodecka-Gazdecka S, Rubiś B. The non-canonical functions of telomerase: to turn off or not to turn off. Mol Biol Rep 2018; 46:1401-1411. [PMID: 30448892 DOI: 10.1007/s11033-018-4496-x] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Accepted: 11/12/2018] [Indexed: 12/19/2022]
Abstract
Telomerase is perceived as an immortality enzyme that enables passing the Hayflick limit. Its main function is telomere restoration but only in a limited group of cells, including cancer cells. Since it is found in a vast majority of cancer cells, it became a natural target for cancer therapy. However, it has much more functions than just altering the metabolism of telomeres-it also reveals numerous so-called non-canonical functions. Thus, a question arises whether it is always beneficial to turn it off when planning a cancer strategy and considering potential side effects? The purpose of this review is to discuss some of the recent discoveries about telomere-independent functions of telomerase in the context of cancer therapy and potential side effects.
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Affiliation(s)
- Aleksandra Romaniuk
- Department of Clinical Chemistry and Molecular Diagnostics, Poznan University of Medical Sciences, 49 Przybyszewskiego St., 60-355, Poznań, Poland
| | - Anna Paszel-Jaworska
- Department of Clinical Chemistry and Molecular Diagnostics, Poznan University of Medical Sciences, 49 Przybyszewskiego St., 60-355, Poznań, Poland
| | - Ewa Totoń
- Department of Clinical Chemistry and Molecular Diagnostics, Poznan University of Medical Sciences, 49 Przybyszewskiego St., 60-355, Poznań, Poland
| | - Natalia Lisiak
- Department of Clinical Chemistry and Molecular Diagnostics, Poznan University of Medical Sciences, 49 Przybyszewskiego St., 60-355, Poznań, Poland
| | - Hanna Hołysz
- Department of Clinical Chemistry and Molecular Diagnostics, Poznan University of Medical Sciences, 49 Przybyszewskiego St., 60-355, Poznań, Poland
| | - Anna Królak
- Department of Clinical Chemistry and Molecular Diagnostics, Poznan University of Medical Sciences, 49 Przybyszewskiego St., 60-355, Poznań, Poland
| | | | - Błażej Rubiś
- Department of Clinical Chemistry and Molecular Diagnostics, Poznan University of Medical Sciences, 49 Przybyszewskiego St., 60-355, Poznań, Poland.
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24
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El Marabti E, Younis I. The Cancer Spliceome: Reprograming of Alternative Splicing in Cancer. Front Mol Biosci 2018; 5:80. [PMID: 30246013 PMCID: PMC6137424 DOI: 10.3389/fmolb.2018.00080] [Citation(s) in RCA: 151] [Impact Index Per Article: 25.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 08/09/2018] [Indexed: 12/15/2022] Open
Abstract
Alternative splicing allows for the expression of multiple RNA and protein isoforms from one gene, making it a major contributor to transcriptome and proteome diversification in eukaryotes. Advances in next generation sequencing technologies and genome-wide analyses have recently underscored the fact that the vast majority of multi-exon genes under normal physiology engage in alternative splicing in tissue-specific and developmental-specific manner. On the other hand, cancer cells exhibit remarkable transcriptome alterations partly by adopting cancer-specific splicing isoforms. These isoforms and their encoded proteins are not insignificant byproducts of the abnormal physiology of cancer cells, but either drivers of cancer progression or small but significant contributors to specific cancer hallmarks. Thus, it is paramount that the pathways that regulate alternative splicing in cancer, including the splicing factors that bind to pre-mRNAs and modulate spliceosome recruitment. In this review, we present a few distinct cases of alternative splicing in cancer, with an emphasis on their regulation as well as their contribution to cancer cell phenotype. Several categories of splicing aberrations are highlighted, including alterations in cancer-related genes that directly affect their pre-mRNA splicing, mutations in genes encoding splicing factors or core spliceosomal subunits, and the seemingly mutation-free disruptions in the balance of the expression of RNA-binding proteins, including components of both the major (U2-dependent) and minor (U12-dependent) spliceosomes. Given that the latter two classes cause global alterations in splicing that affect a wide range of genes, it remains a challenge to identify the ones that contribute to cancer progression. These challenges necessitate a systematic approach to decipher these aberrations and their impact on cancer. Ultimately, a sufficient understanding of splicing deregulation in cancer is predicted to pave the way for novel and innovative RNA-based therapies.
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Affiliation(s)
- Ettaib El Marabti
- Biological Sciences Program, Carnegie Mellon University in Qatar, Doha, Qatar
| | - Ihab Younis
- Biological Sciences Program, Carnegie Mellon University in Qatar, Doha, Qatar
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25
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Giunco S, Petrara MR, Zangrossi M, Celeghin A, De Rossi A. Extra-telomeric functions of telomerase in the pathogenesis of Epstein-Barr virus-driven B-cell malignancies and potential therapeutic implications. Infect Agent Cancer 2018; 13:14. [PMID: 29643934 PMCID: PMC5892012 DOI: 10.1186/s13027-018-0186-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Accepted: 03/29/2018] [Indexed: 02/06/2023] Open
Abstract
The Epstein-Barr virus (EBV) is a ubiquitous human γ-herpesvirus causally linked to a broad spectrum of both lymphoid and epithelial malignancies. In order to maintain its persistence in host cells and promote tumorigenesis, EBV must restrict its lytic cycle, which would ultimately lead to cell death, selectively express latent viral proteins, and establish an unlimited proliferative potential. The latter step depends on the maintenance of telomere length provided by telomerase. The viral oncoprotein LMP-1 activates TERT, the catalytic component of telomerase. In addition to its canonical role in stabilizing telomeres, TERT may promote EBV-driven tumorigenesis through extra-telomeric functions. TERT contributes toward preserving EBV latency; in fact, through the NOTCH2/BATF pathway, TERT negatively affects the expression of BZLF1, the master regulator of the EBV lytic cycle. In contrast, TERT inhibition triggers a complete EBV lytic cycle, leading to the death of EBV-infected cells. Interestingly, short-term TERT inhibition causes cell cycle arrest and apoptosis, partly by inducing telomere-independent activation of the ATM/ATR/TP53 pathway. Importantly, TERT inhibition also sensitizes EBV-positive tumor cells to antiviral therapy and enhances the pro-apoptotic effects of chemotherapeutic agents. We provide here an overview on how the extra-telomeric functions of TERT contribute to EBV-driven tumorigenesis. We also discuss the potential therapeutic approach of TERT inhibition in EBV-driven malignancies.
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Affiliation(s)
- Silvia Giunco
- 1Immunology and Molecular Oncology Unit, Istituto Oncologico Veneto (IOV)-IRCCS, Padova, Italy
| | - Maria Raffaella Petrara
- 2Department of Surgery, Oncology and Gastroenterology, Section of Oncology and Immunology, University of Padova, Padova, Italy
| | - Manuela Zangrossi
- 2Department of Surgery, Oncology and Gastroenterology, Section of Oncology and Immunology, University of Padova, Padova, Italy
| | - Andrea Celeghin
- 2Department of Surgery, Oncology and Gastroenterology, Section of Oncology and Immunology, University of Padova, Padova, Italy
| | - Anita De Rossi
- 1Immunology and Molecular Oncology Unit, Istituto Oncologico Veneto (IOV)-IRCCS, Padova, Italy.,2Department of Surgery, Oncology and Gastroenterology, Section of Oncology and Immunology, University of Padova, Padova, Italy
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26
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Li G, Shen J, Cao J, Zhou G, Lei T, Sun Y, Gao H, Ding Y, Xu W, Zhan Z, Chen Y, Huang H. Alternative splicing of human telomerase reverse transcriptase in gliomas and its modulation mediated by CX-5461. JOURNAL OF EXPERIMENTAL & CLINICAL CANCER RESEARCH : CR 2018; 37:78. [PMID: 29631594 PMCID: PMC5891986 DOI: 10.1186/s13046-018-0749-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Accepted: 04/02/2018] [Indexed: 02/08/2023]
Abstract
Background Glioma is a heterogeneous, invasive primary brain tumor with a wide range of patient survival and a lack of reliable prognostic biomarkers. Human telomerase reverse transcriptase (hTERT) has been reported in the presence of multiple transcripts in various tumor systems. The biological function and precise regulatory mechanisms of hTERT transcripts remain uncertain. Methods Alternative splicing of hTERT and telomerase activity were examined in 96 glioma specimens, including 38 glioblastomas (GBMs), 23 oligodendrogliomas (ODMs), and 35 oligoastrocytomas (OAMs). The correlation between telomerase activity or hTERT transcripts and patient clinical characteristics was investigated. We examined the regulation of alternative splicing of hTERT and telomerase activity by G-quadruplex stabilizer CX-5461 in GBM cells. The biological effects of CX-5461 on GBM cell lines, including inhibition of cell proliferation, effects on cell cycle/apoptosis, and telomere DNA damage were further explored. Results The β splicing was verified in human gliomas and hTERT+β was significantly correlated with higher telomerase activity, higher KPS, larger tumor size, and higher tumor grades. Meanwhile, glioma patients lacking hTERT+β expression or telomerase activity showed a significant survival benefit. Notably, CX-5461 altered hTERT splicing patterns, leading to an increase of hTERT-β transcript and a decrease of hTERT+β transcript expression, which inhibits telomerase activity. In addition, CX-5461 had cytotoxic effects on GBM cells and caused telomere DNA damage response, induced G2/M arrest and apoptosis. Conclusions The hTERT+β is verified to be correlated with clinical parameters in gliomas, and could serve as a prognostic marker or possibly therapeutic target for gliomas. CX-5461 can regulate the splicing pattern of hTERT, inhibit telomerase activity, and kill GBM cells.
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Affiliation(s)
- Guihong Li
- Department of Neurosurgery, First Hospital of Jilin University, Changchun, 130021, China.,Department of Neurosurgery, First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450000, China
| | - Jing Shen
- Department of Cardiology, Shengze Hospital of Jiangsu Province, Suzhou, 215200, China
| | - Junguo Cao
- Department of Neurosurgery, First Hospital of Jilin University, Changchun, 130021, China
| | - Guangtong Zhou
- Department of Neurosurgery, First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450000, China
| | - Ting Lei
- Department of Neurovascular Research Laboratory and Neuroscience, Universitat Autonoma de Barcelona, 08035, Barcelona, Spain
| | - Yuxue Sun
- Department of Neurosurgery, First Hospital of Jilin University, Changchun, 130021, China
| | - Haijun Gao
- Department of Neurosurgery, First Hospital of Jilin University, Changchun, 130021, China
| | - Yaonan Ding
- Department of Neurosurgery, First Hospital of Jilin University, Changchun, 130021, China
| | - Weidong Xu
- Department of Neurosurgery, First Hospital of Jilin University, Changchun, 130021, China
| | - Zhixin Zhan
- Department of Neurosurgery, First Hospital of Jilin University, Changchun, 130021, China
| | - Yong Chen
- Department of Neurosurgery, First Hospital of Jilin University, Changchun, 130021, China.
| | - Haiyan Huang
- Department of Neurosurgery, First Hospital of Jilin University, Changchun, 130021, China.
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27
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Leão R, Apolónio JD, Lee D, Figueiredo A, Tabori U, Castelo-Branco P. Mechanisms of human telomerase reverse transcriptase (hTERT) regulation: clinical impacts in cancer. J Biomed Sci 2018. [PMID: 29526163 PMCID: PMC5846307 DOI: 10.1186/s12929-018-0422-8] [Citation(s) in RCA: 144] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Background Limitless self-renewal is one of the hallmarks of cancer and is attained by telomere maintenance, essentially through telomerase (hTERT) activation. Transcriptional regulation of hTERT is believed to play a major role in telomerase activation in human cancers. Main body The dominant interest in telomerase results from its role in cancer. The role of telomeres and telomere maintenance mechanisms is well established as a major driving force in generating chromosomal and genomic instability. Cancer cells have acquired the ability to overcome their fate of senescence via telomere length maintenance mechanisms, mainly by telomerase activation. hTERT expression is up-regulated in tumors via multiple genetic and epigenetic mechanisms including hTERT amplifications, hTERT structural variants, hTERT promoter mutations and epigenetic modifications through hTERT promoter methylation. Genetic (hTERT promoter mutations) and epigenetic (hTERT promoter methylation and miRNAs) events were shown to have clinical implications in cancers that depend on hTERT activation. Knowing that telomeres are crucial for cellular self-renewal, the mechanisms responsible for telomere maintenance have a crucial role in cancer diseases and might be important oncological biomarkers. Thus, rather than quantifying TERT expression and its correlation with telomerase activation, the discovery and the assessment of the mechanisms responsible for TERT upregulation offers important information that may be used for diagnosis, prognosis, and treatment monitoring in oncology. Furthermore, a better understanding of these mechanisms may promote their translation into effective targeted cancer therapies. Conclusion Herein, we reviewed the underlying mechanisms of hTERT regulation, their role in oncogenesis, and the potential clinical applications in telomerase-dependent cancers.
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Affiliation(s)
- Ricardo Leão
- Division of Urology, Department of Surgery Princess Margaret Cancer Centre, University Health Network, 610 University Ave 3-130, Toronto, ON, M5G 2M9, Canada. .,Arthur and Sonia Labatt Brain Tumor Research Center, The Hospital for Sick Children, University of Toronto, 555 University Avenue, Toronto, ON, M5G 1X8, Canada. .,Faculty of Medicine, University of Coimbra, R. Larga, 3004-504, Coimbra, Coimbra, Portugal. .,Department of Urology, Coimbra University Hospital, Coimbra, Portugal.
| | - Joana Dias Apolónio
- Regenerative Medicine Program, Department of Biomedical Sciences and Medicine, University of Algarve, Edifício 2 - Ala Norte, 8005-139, Faro, Portugal.,Centre for Biomedical Research (CBMR), University of Algarve, Faro, Portugal.,Algarve Biomedical Center, Campus Gambelas, Faro, Portugal
| | - Donghyun Lee
- Arthur and Sonia Labatt Brain Tumor Research Center, The Hospital for Sick Children, University of Toronto, 555 University Avenue, Toronto, ON, M5G 1X8, Canada
| | - Arnaldo Figueiredo
- Faculty of Medicine, University of Coimbra, R. Larga, 3004-504, Coimbra, Coimbra, Portugal.,Department of Urology, Coimbra University Hospital, Coimbra, Portugal
| | - Uri Tabori
- Arthur and Sonia Labatt Brain Tumor Research Center, The Hospital for Sick Children, University of Toronto, 555 University Avenue, Toronto, ON, M5G 1X8, Canada.,Division of Haematology/Oncology, The Hospital for Sick Children, 555 University Avenue, Toronto, M5G 1X8ON, Canada
| | - Pedro Castelo-Branco
- Regenerative Medicine Program, Department of Biomedical Sciences and Medicine, University of Algarve, Edifício 2 - Ala Norte, 8005-139, Faro, Portugal.,Centre for Biomedical Research (CBMR), University of Algarve, Faro, Portugal.,Algarve Biomedical Center, Campus Gambelas, Faro, Portugal
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