1
|
Shen Z, Wang Y, Wang G, Gu W, Zhao S, Hu X, Liu W, Cai Y, Ma Z, Gautam RK, Jia J, Wan CC, Yan T. Research progress of small-molecule drugs in targeting telomerase in human cancer and aging. Chem Biol Interact 2023; 382:110631. [PMID: 37451664 DOI: 10.1016/j.cbi.2023.110631] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2023] [Revised: 05/17/2023] [Accepted: 07/11/2023] [Indexed: 07/18/2023]
Abstract
Telomeres are unique structures located at the ends of linear chromosomes, responsible for stabilizing chromosomal structures. They are synthesized by telomerase, a reverse transcriptase ribonucleoprotein complex. Telomerase activity is generally absent in human somatic cells, except in stem cells and germ cells. Every time a cell divides, the telomere sequence is shortened, eventually leading to replicative senescence and cell apoptosis when the telomeres reach a critical limit. However, most human cancer cells exhibit increased telomerase activity, allowing them to divide continuously. The importance of telomerase in cancer and aging has made developing drugs targeting telomerase a focus of research. Such drugs can inhibit cancer cell growth and delay aging by enhancing telomerase activity in telomere-related syndromes or diseases. This review provides an overview of telomeres, telomerase, and their regulation in cancer and aging, and highlights small-molecule drugs targeting telomerase in these fields.
Collapse
Affiliation(s)
- Ziyi Shen
- School of Life Sciences, Shanghai University, 99 Shangda Road, Shanghai, 200444, China
| | - Yuanhui Wang
- School of Life Sciences, Shanghai University, 99 Shangda Road, Shanghai, 200444, China
| | - Guanzhen Wang
- School of Life Sciences, Shanghai University, 99 Shangda Road, Shanghai, 200444, China; University and College Key Lab of Natural Product Chemistry and Application in Xinjiang, School of Chemistry and Environmental Science, Yili Normal University, Yining, 835000, China
| | - Wei Gu
- School of Life Sciences, Shanghai University, 99 Shangda Road, Shanghai, 200444, China
| | - Shengchao Zhao
- School of Life Sciences, Shanghai University, 99 Shangda Road, Shanghai, 200444, China; University and College Key Lab of Natural Product Chemistry and Application in Xinjiang, School of Chemistry and Environmental Science, Yili Normal University, Yining, 835000, China
| | - Xiaomeng Hu
- University and College Key Lab of Natural Product Chemistry and Application in Xinjiang, School of Chemistry and Environmental Science, Yili Normal University, Yining, 835000, China; Huzhou Central Hospital, Huzhou, 313000, China
| | - Wei Liu
- University and College Key Lab of Natural Product Chemistry and Application in Xinjiang, School of Chemistry and Environmental Science, Yili Normal University, Yining, 835000, China
| | - Yi Cai
- Key Laboratory of Molecular Target & Clinical Pharmacology and the State & NMPA Key Laboratory of Respiratory Disease, School of Pharmaceutical Sciences & The Fifth Affiliated Hospital, Guangzhou Medical University, Guangzhou, 511436, China
| | - Zhihong Ma
- Huzhou Central Hospital, Huzhou, 313000, China
| | - Rupesh K Gautam
- Department of Pharmacology, Indore Institute of Pharmacy, Indore, 453331, India
| | - Jia Jia
- School of Life Sciences, Shanghai University, 99 Shangda Road, Shanghai, 200444, China; Translational Medicine Center, Zhejiang Xinda hospital, School of Medicine&Nursing, Huzhou University, Huzhou, 313099, China.
| | - Chunpeng Craig Wan
- Jiangxi Key Laboratory for Postharvest Technology and Nondestructive Testing of Fruits and Vegetables, College of Agronomy, Jiangxi Agricultural University, Nanchang, 330045, China.
| | - Tingdong Yan
- School of Life Sciences, Shanghai University, 99 Shangda Road, Shanghai, 200444, China; Translational Medicine Center, Zhejiang Xinda hospital, School of Medicine&Nursing, Huzhou University, Huzhou, 313099, China.
| |
Collapse
|
2
|
Kim JJ, Sayed ME, Ahn A, Slusher AL, Ying JY, Ludlow AT. Dynamics of TERT regulation via alternative splicing in stem cells and cancer cells. PLoS One 2023; 18:e0289327. [PMID: 37531400 PMCID: PMC10395990 DOI: 10.1371/journal.pone.0289327] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 07/17/2023] [Indexed: 08/04/2023] Open
Abstract
Part of the regulation of telomerase activity includes the alternative splicing (AS) of the catalytic subunit telomerase reverse transcriptase (TERT). Although a therapeutic window for telomerase/TERT inhibition exists between cancer cells and somatic cells, stem cells express TERT and rely on telomerase activity for physiological replacement of cells. Therefore, identifying differences in TERT regulation between stem cells and cancer cells is essential for developing telomerase inhibition-based cancer therapies that reduce damage to stem cells. In this study, we measured TERT splice variant expression and telomerase activity in induced pluripotent stem cells (iPSCs), neural progenitor cells (NPCs), and non-small cell lung cancer cells (NSCLC, Calu-6 cells). We observed that a NOVA1-PTBP1-PTBP2 axis regulates TERT alternative splicing (AS) in iPSCs and their differentiation into NPCs. We also found that splice-switching of TERT, which regulates telomerase activity, is induced by different cell densities in stem cells but not cancer cells. Lastly, we identified cell type-specific splicing factors that regulate TERT AS. Overall, our findings represent an important step forward in understanding the regulation of TERT AS in stem cells and cancer cells.
Collapse
Affiliation(s)
- Jeongjin J Kim
- School of Kinesiology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Mohammed E Sayed
- School of Kinesiology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Alexander Ahn
- School of Kinesiology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Aaron L Slusher
- School of Kinesiology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Jeffrey Y Ying
- School of Kinesiology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Andrew T Ludlow
- School of Kinesiology, University of Michigan, Ann Arbor, Michigan, United States of America
| |
Collapse
|
3
|
Tian Z, Yu T, Liu J, Wang T, Higuchi A. Introduction to stem cells. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2023; 199:3-32. [PMID: 37678976 DOI: 10.1016/bs.pmbts.2023.02.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/17/2023]
Abstract
Stem cells have self-renewal capability and can proliferate and differentiate into a variety of functionally active cells that can serve in various tissues and organs. This review discusses the history, definition, and classification of stem cells. Human pluripotent stem cells (hPSCs) mainly include embryonic stem cells (hESCs) and induced pluripotent stem cells (hiPSCs). Embryonic stem cells are derived from the inner cell mass of the embryo. Induced pluripotent stem cells are derived from reprogramming somatic cells. Pluripotent stem cells have the ability to differentiate into cells derived from all three germ layers (endoderm, mesoderm, and ectoderm). Adult stem cells can be multipotent or unipotent and can produce tissue-specific terminally differentiated cells. Stem cells can be used in cell therapy to replace and regenerate damaged tissues or organs.
Collapse
Affiliation(s)
- Zeyu Tian
- State Key Laboratory of Ophthalmology, Optometry and Visual Science, Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, P.R. China
| | - Tao Yu
- State Key Laboratory of Ophthalmology, Optometry and Visual Science, Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, P.R. China
| | - Jun Liu
- State Key Laboratory of Ophthalmology, Optometry and Visual Science, Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, P.R. China
| | - Ting Wang
- State Key Laboratory of Ophthalmology, Optometry and Visual Science, Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, P.R. China.
| | - Akon Higuchi
- State Key Laboratory of Ophthalmology, Optometry and Visual Science, Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, P.R. China; Department of Chemical and Materials Engineering, National Central University, Jhongli, Taoyuan, Taiwan.
| |
Collapse
|
4
|
Apolónio JD, Dias JS, Fernandes MT, Komosa M, Lipman T, Zhang CH, Leão R, Lee D, Nunes NM, Maia AT, Morera JL, Vicioso L, Tabori U, Castelo-Branco P. THOR is a targetable epigenetic biomarker with clinical implications in breast cancer. Clin Epigenetics 2022; 14:178. [PMID: 36529814 PMCID: PMC9759897 DOI: 10.1186/s13148-022-01396-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2022] [Accepted: 12/02/2022] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Breast cancer (BC) is the most frequently diagnosed cancer and a leading cause of death among women worldwide. Early BC is potentially curable, but the mortality rates still observed among BC patients demonstrate the urgent need of novel and more effective diagnostic and therapeutic options. Limitless self-renewal is a hallmark of cancer, governed by telomere maintenance. In around 95% of BC cases, this process is achieved by telomerase reactivation through upregulation of the human telomerase reverse transcriptase (hTERT). The hypermethylation of a specific region within the hTERT promoter, termed TERT hypermethylated oncological region (THOR) has been associated with increased hTERT expression in cancer. However, its biological role and clinical potential in BC have never been studied to the best of our knowledge. Therefore, we aimed to investigate the role of THOR as a biomarker and explore the functional impact of THOR methylation status in hTERT upregulation in BC. RESULTS THOR methylation status in BC was assessed by pyrosequencing on discovery and validation cohorts. We found that THOR is significantly hypermethylated in malignant breast tissue when compared to benign tissue (40.23% vs. 12.81%, P < 0.0001), differentiating malignant tumor from normal tissue from the earliest stage of disease. Using a reporter assay, the addition of unmethylated THOR significantly reduced luciferase activity by an average 1.8-fold when compared to the hTERT core promoter alone (P < 0.01). To further investigate its biological impact on hTERT transcription, targeted THOR demethylation was performed using novel technology based on CRISPR-dCas9 system and significant THOR demethylation was achieved. Cells previously demethylated on THOR region did not develop a histologic cancer phenotype in in vivo assays. Additional studies are required to validate these observations and to unravel the causality between THOR hypermethylation and hTERT upregulation in BC. CONCLUSIONS THOR hypermethylation is an important epigenetic mark in breast tumorigenesis, representing a promising biomarker and therapeutic target in BC. We revealed that THOR acts as a repressive regulatory element of hTERT and that its hypermethylation is a relevant mechanism for hTERT upregulation in BC.
Collapse
Affiliation(s)
- Joana Dias Apolónio
- grid.7157.40000 0000 9693 350XFaculty of Medicine and Biomedical Sciences (FMCB), University of Algarve, Gambelas Campus, Bld. 2, 8005-139 Faro, Portugal ,grid.7157.40000 0000 9693 350XAlgarve Biomedical Center Research Institute (ABC-RI), University of Algarve, Gambelas Campus, 8005-139 Faro, Portugal ,grid.7157.40000 0000 9693 350XAlgarve Biomedical Center (ABC), University of Algarve, Gambelas Campus, 8005-139 Faro, Portugal ,grid.42327.300000 0004 0473 9646Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON Canada
| | - João S. Dias
- University Hospital Center of Algarve, Faro, Portugal
| | - Mónica Teotónio Fernandes
- grid.7157.40000 0000 9693 350XAlgarve Biomedical Center Research Institute (ABC-RI), University of Algarve, Gambelas Campus, 8005-139 Faro, Portugal ,grid.7157.40000 0000 9693 350XAlgarve Biomedical Center (ABC), University of Algarve, Gambelas Campus, 8005-139 Faro, Portugal ,grid.7157.40000 0000 9693 350XEscola Superior de Saúde (ESSUAlg), Universidade Do Algarve, Faro, Portugal
| | - Martin Komosa
- grid.42327.300000 0004 0473 9646Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON Canada ,grid.17063.330000 0001 2157 2938Arthur and Sonia Labatt Brain Tumor Research Center, The Hospital for Sick Children, University of Toronto, Toronto, ON Canada
| | - Tatiana Lipman
- grid.42327.300000 0004 0473 9646Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON Canada ,grid.17063.330000 0001 2157 2938Arthur and Sonia Labatt Brain Tumor Research Center, The Hospital for Sick Children, University of Toronto, Toronto, ON Canada
| | - Cindy H. Zhang
- grid.42327.300000 0004 0473 9646Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON Canada ,grid.17063.330000 0001 2157 2938Arthur and Sonia Labatt Brain Tumor Research Center, The Hospital for Sick Children, University of Toronto, Toronto, ON Canada
| | - Ricardo Leão
- grid.8051.c0000 0000 9511 4342Faculty of Medicine, University of Coimbra, Coimbra, Portugal
| | - Donghyun Lee
- grid.42327.300000 0004 0473 9646Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON Canada ,grid.17063.330000 0001 2157 2938Arthur and Sonia Labatt Brain Tumor Research Center, The Hospital for Sick Children, University of Toronto, Toronto, ON Canada
| | - Nuno Miguel Nunes
- grid.42327.300000 0004 0473 9646Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON Canada ,grid.17063.330000 0001 2157 2938Arthur and Sonia Labatt Brain Tumor Research Center, The Hospital for Sick Children, University of Toronto, Toronto, ON Canada
| | - Ana-Teresa Maia
- grid.7157.40000 0000 9693 350XFaculty of Medicine and Biomedical Sciences (FMCB), University of Algarve, Gambelas Campus, Bld. 2, 8005-139 Faro, Portugal ,grid.7157.40000 0000 9693 350XAlgarve Biomedical Center (ABC), University of Algarve, Gambelas Campus, 8005-139 Faro, Portugal ,grid.7157.40000 0000 9693 350XCenter for Research in Health Technologies and Information Systems (CINTESIS@RISE), University of Algarve, Gambelas Campus, 8005-139 Faro, Portugal
| | | | - Luis Vicioso
- grid.10215.370000 0001 2298 7828Faculty of Medicine, Department of Histology and Pathological Anatomy, University of Malaga, Malaga, Spain
| | - Uri Tabori
- grid.42327.300000 0004 0473 9646Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON Canada ,grid.17063.330000 0001 2157 2938Arthur and Sonia Labatt Brain Tumor Research Center, The Hospital for Sick Children, University of Toronto, Toronto, ON Canada ,grid.42327.300000 0004 0473 9646Division of Hematology/Oncology, The Hospital for Sick Children, Toronto, ON Canada
| | - Pedro Castelo-Branco
- grid.7157.40000 0000 9693 350XFaculty of Medicine and Biomedical Sciences (FMCB), University of Algarve, Gambelas Campus, Bld. 2, 8005-139 Faro, Portugal ,grid.7157.40000 0000 9693 350XAlgarve Biomedical Center Research Institute (ABC-RI), University of Algarve, Gambelas Campus, 8005-139 Faro, Portugal ,grid.7157.40000 0000 9693 350XAlgarve Biomedical Center (ABC), University of Algarve, Gambelas Campus, 8005-139 Faro, Portugal ,grid.421010.60000 0004 0453 9636Champalimaud Research Program, Champalimaud Centre for the Unknown, Lisbon, Portugal
| |
Collapse
|
5
|
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.
Collapse
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: )
| |
Collapse
|
6
|
Telomerase in Cancer: Function, Regulation, and Clinical Translation. Cancers (Basel) 2022; 14:cancers14030808. [PMID: 35159075 PMCID: PMC8834434 DOI: 10.3390/cancers14030808] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 01/29/2022] [Accepted: 02/02/2022] [Indexed: 02/04/2023] Open
Abstract
Simple Summary Cells undergoing malignant transformation must circumvent replicative senescence and eventual cell death associated with progressive telomere shortening that occurs through successive cell division. To do so, malignant cells reactivate telomerase to extend their telomeres and achieve cellular immortality, which is a “Hallmark of Cancer”. Here we review the telomere-dependent and -independent functions of telomerase in cancer, as well as its potential as a biomarker and therapeutic target to diagnose and treat cancer patients. Abstract During the process of malignant transformation, cells undergo a series of genetic, epigenetic, and phenotypic alterations, including the acquisition and propagation of genomic aberrations that impart survival and proliferative advantages. These changes are mediated in part by the induction of replicative immortality that is accompanied by active telomere elongation. Indeed, telomeres undergo dynamic changes to their lengths and higher-order structures throughout tumor formation and progression, processes overseen in most cancers by telomerase. Telomerase is a multimeric enzyme whose function is exquisitely regulated through diverse transcriptional, post-transcriptional, and post-translational mechanisms to facilitate telomere extension. In turn, telomerase function depends not only on its core components, but also on a suite of binding partners, transcription factors, and intra- and extracellular signaling effectors. Additionally, telomerase exhibits telomere-independent regulation of cancer cell growth by participating directly in cellular metabolism, signal transduction, and the regulation of gene expression in ways that are critical for tumorigenesis. In this review, we summarize the complex mechanisms underlying telomere maintenance, with a particular focus on both the telomeric and extratelomeric functions of telomerase. We also explore the clinical utility of telomeres and telomerase in the diagnosis, prognosis, and development of targeted therapies for primary, metastatic, and recurrent cancers.
Collapse
|
7
|
Ricci C, Morandi L, Ambrosi F, Righi A, Gibertoni D, Maletta F, Agostinelli C, Corradini AG, Uccella S, Asioli S, Sessa F, La Rosa S, Papotti MG, Asioli S. Intron 4-5 hTERT DNA Hypermethylation in Merkel Cell Carcinoma: Frequency, Association with Other Clinico-pathological Features and Prognostic Relevance. Endocr Pathol 2021; 32:385-395. [PMID: 33909215 PMCID: PMC8370894 DOI: 10.1007/s12022-021-09669-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 02/15/2021] [Indexed: 12/23/2022]
Abstract
Merkel cell carcinoma (MCC) is an aggressive skin tumor with neuroendocrine differentiation, mainly affecting elderly population or immunocompromised individuals. As methylation of the human telomerase reverse transcriptase (mhTERT) has been shown to be a prognostic factor in different tumors, we investigated its role in MCC, in particular in intron 4-5 where rs10069690 has been mapped and recognized as a cancer susceptibility locus. DNA methylation analysis of hTERT gene was assessed retrospectively in a cohort of 69 MCC patients from the University of Bologna, University of Turin and University of Insubria. Overall mortality was evaluated with Kaplan-Meier curves and multivariable Royston-Parmar models. High levels of mhTERT (mhTERThigh) (HR = 2.500, p = 0.015) and p63 (HR = 2.659, p = 0.016) were the only two clinico-pathological features significantly associated with a higher overall mortality at the multivariate analysis. We did not find different levels of mhTERT between MCPyV (+) and (-) cases (21 vs 14, p = 0.554); furthermore, mhTERThigh was strongly associated with older age (80.5 vs 72 years, p = 0.026), no angioinvasion (40.7% vs 71.0%, p = 0.015), lower Ki67 (50 vs 70%, p = 0.005), and PD-L1 expressions in both tumor (0 vs 3%, p = 0.021) and immune cells (0 vs 10%, p = 0.002). mhTERT is a frequently involved epigenetic mechanism and a relevant prognostic factor in MCC. In addition, it belongs to the shared oncogenic pathways of MCC (MCPyV and UV-radiations) and it could be crucial, together with other epigenetic and genetic mechanisms as gene amplification, in determining the final levels of hTERT mRNA and telomerase activity in these patients.
Collapse
Affiliation(s)
- Costantino Ricci
- Pathology Unit, Maggiore Hospital, AUSL Bologna, Bologna, Italy
- Department of Experimental, Diagnostic and Specialty Medicine (DIMES), University of Bologna, Bologna, Italy
| | - Luca Morandi
- Department of Biomedical and Neuromotor Sciences, Functional MR Unit, IRCCS Istituto delle Scienze Neurologiche, Bologna, Italy
| | | | - Alberto Righi
- Department of Pathology, IRCCS Istituto Ortopedico Rizzoli, Bologna, Italy
| | - Dino Gibertoni
- Department of Biomedical and Neuromotor Sciences, Unit of Hygiene and Biostatistics, University of Bologna, Bologna, Italy
| | - Francesca Maletta
- Department of Oncology, University of Turin, Città Della Salute Hospital, Turin, Italy
| | - Claudio Agostinelli
- Department of Experimental, Diagnostic and Specialty Medicine (DIMES), University of Bologna, Bologna, Italy
- Haematopathology Unit, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy
| | - Angelo Gianluca Corradini
- Department of Biomedical and Neuromotor Sciences, Functional MR Unit, IRCCS Istituto delle Scienze Neurologiche, Bologna, Italy
| | - Silvia Uccella
- Unit of Pathology, Department of Medicine and Surgery, University of Insubria, Varese, Italy
| | - Silvia Asioli
- Unit of Pathology, Morgagni-Pierantoni Hospital, Forlì, 47121, Italy
| | - Fausto Sessa
- Unit of Pathology, Department of Medicine and Surgery, University of Insubria, Varese, Italy
| | - Stefano La Rosa
- Institute of Pathology, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Mauro Giulio Papotti
- Department of Oncology, University of Turin, Città Della Salute Hospital, Turin, Italy
| | - Sofia Asioli
- Department of Biomedical and Neuromotor Sciences (DIBINEM) Surgical Pathology Section- Alma Mater Studiorum , University of Bologna , Bologna, Italy.
| |
Collapse
|
8
|
McKelvey BA, Zeiger MA, Umbricht CB. Characterization of TERT and BRAF copy number variation in papillary thyroid carcinoma: An analysis of the cancer genome atlas study. Genes Chromosomes Cancer 2021; 60:403-409. [PMID: 33305870 PMCID: PMC9927632 DOI: 10.1002/gcc.22928] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Accepted: 12/07/2020] [Indexed: 12/18/2022] Open
Abstract
Alterations in the genome, including mutations and copy number variation (CNV), can drive cancer progression. The Cancer Genome Atlas (TCGA) project studying papillary thyroid cancer (PTC) identified a number of recurrent arm-level copy number amplifications, some spanning genes that are also commonly mutated in thyroid cancer. Herein, we focus on the role of TERT and BRAF CNV in PTC, including its relation to mutation status, gene expression, and clinicopathological characteristics. Utilizing TCGA CNV data, we identified focal amplifications and deletions involving the TERT and BRAF loci. TERT amplifications are more frequent in later stage thyroid tumors; in contrast, BRAF amplifications are not associated with stage. Furthermore, TERT amplifications are more frequently found in tumors also harboring TERT mutations, the combination further increasing TERT expression. Conversely, BRAF amplifications are more frequently found in BRAF wildtype tumors, and are more common in the follicular subtype of PTC as well as classic PTCs associated with a high follicular component and a RAS-like expression profile (assessed by the BRAF/RAS score). This is the first study to examine the TCGA thyroid dataset for gene-level CNV of TERT and BRAF, and their relationship with mutation status, tumor type and tumor stage. Assessing the differences in patterns of TERT and BRAF amplifications in the context of the mutation status of these genes may provide insight into the differing roles CNV can play depending on tumor type, and may lead to a better understanding of cancer drivers in thyroid cancer.
Collapse
Affiliation(s)
- Brittany A. McKelvey
- Department of Surgery, Johns Hopkins University, Baltimore, Maryland,Department of Molecular Biology and Genetics, Johns Hopkins University, Baltimore, Maryland
| | - Martha A. Zeiger
- Surgical Oncology Program, National Cancer Institute, National Institutes of Health, Bethesda, Maryland
| | - Christopher B. Umbricht
- Department of Surgery, Johns Hopkins University, Baltimore, Maryland,Department of Oncology, Johns Hopkins University, Baltimore, Maryland,Department of Pathology, Johns Hopkins University, Baltimore, Maryland
| |
Collapse
|
9
|
Koubová J, Pangrácová M, Jankásek M, Lukšan O, Jehlík T, Brabcová J, Jedlička P, Křivánek J, Čapková Frydrychová R, Hanus R. Long-lived termite kings and queens activate telomerase in somatic organs. Proc Biol Sci 2021; 288:20210511. [PMID: 33878922 PMCID: PMC8059557 DOI: 10.1098/rspb.2021.0511] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Kings and queens of termites, like queens of other advanced eusocial insects, are endowed with admirable longevity, which dramatically exceeds the life expectancies of their non-reproducing nest-mates and related solitary insects. In the quest to find the mechanisms underlying the longevity of termite reproductives, we focused on somatic maintenance mediated by telomerase. This ribonucleoprotein is well established for pro-longevity functions in vertebrates, thanks primarily to its ability of telomere extension. However, its participation in lifespan regulation of insects, including the eusocial taxa, remains understudied. Here, we report a conspicuous increase of telomerase abundance and catalytic activity in the somatic organs of primary and secondary reproductives of the termite Prorhinotermes simplex and confirm a similar pattern in two other termite species. These observations stand in contrast with the telomerase downregulation characteristic for most adult somatic tissues in vertebrates and also in solitary insects and non-reproducing castes of termites. At the same time, we did not observe caste-specific differences in telomere lengths that might explain the differential longevity of termite castes. We conclude that although the telomerase activation in termite reproductives is in line with the broadly assumed association between telomerase and longevity, its direct phenotypic impact remains to be elucidated.
Collapse
Affiliation(s)
- Justina Koubová
- Biology Centre of the Czech Academy of Sciences, Institute of Entomology, České Budějovice, Czech Republic.,Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
| | - Marie Pangrácová
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Prague, Czech Republic.,Faculty of Science, Charles University in Prague, Prague, Czech Republic
| | - Marek Jankásek
- Faculty of Science, Charles University in Prague, Prague, Czech Republic
| | - Ondřej Lukšan
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Prague, Czech Republic
| | - Tomáš Jehlík
- Biology Centre of the Czech Academy of Sciences, Institute of Entomology, České Budějovice, Czech Republic.,Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
| | - Jana Brabcová
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Prague, Czech Republic
| | - Pavel Jedlička
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Prague, Czech Republic.,Institute of Biophysics of the Czech Academy of Sciences, Brno, Czech Republic
| | - Jan Křivánek
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Prague, Czech Republic
| | - Radmila Čapková Frydrychová
- Biology Centre of the Czech Academy of Sciences, Institute of Entomology, České Budějovice, Czech Republic.,Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
| | - Robert Hanus
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Prague, Czech Republic
| |
Collapse
|
10
|
Yuan X, Dai M, Xu D. Telomere-related Markers for Cancer. Curr Top Med Chem 2020; 20:410-432. [PMID: 31903880 PMCID: PMC7475940 DOI: 10.2174/1568026620666200106145340] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Revised: 12/03/2019] [Accepted: 12/14/2019] [Indexed: 02/06/2023]
Abstract
Telomeres are structurally nucleoprotein complexes at termini of linear chromosomes and essential to chromosome stability/integrity. In normal human cells, telomere length erodes progressively with each round of cell divisions, which serves as an important barrier to uncontrolled proliferation and malignant transformation. In sharp contrast, telomere maintenance is a key feature of human malignant cells and required for their infinite proliferation and maintenance of other cancer hallmarks as well. Thus, a telomere-based anti-cancer strategy has long been suggested. However, clinically efficient and specific drugs targeting cancer telomere-maintenance have still been in their infancy thus far. To achieve this goal, it is highly necessary to elucidate how exactly cancer cells maintain functional telomeres. In the last two decades, numerous studies have provided profound mechanistic insights, and the identified mechanisms include the aberrant activation of telomerase or the alternative lengthening of telomere pathway responsible for telomere elongation, dysregulation and mutation of telomere-associated factors, and other telomere homeostasis-related signaling nodes. In the present review, these various strategies employed by malignant cells to regulate their telomere length, structure and function have been summarized, and potential implications of these findings in the rational development of telomere-based cancer therapy and other clinical applications for precision oncology have been discussed.
Collapse
Affiliation(s)
- Xiaotian Yuan
- Center for Reproductive Medicine, Shandong University, Jinan, 250012, China
| | - Mingkai Dai
- Central Research Laboratory, Shandong University Second Hospital, Jinan, 250033, China.,Karolinska Institute Collaborative Laboratory for Cancer and Stem Cell Research, Shandong University Second Hospital, Jinan, 250033, China
| | - Dawei Xu
- Karolinska Institute Collaborative Laboratory for Cancer and Stem Cell Research, Shandong University Second Hospital, Jinan, 250033, China.,Department of Medicine, Division of Hematology, Center for Molecular Medicine (CMM) and Bioclinicum, Karolinska Institute and Karolinska University Hospital Solna, Solna 171 64, Sweden
| |
Collapse
|
11
|
McKelvey BA, Gilpatrick T, Wang Y, Timp W, Umbricht CB, Zeiger MA. Characterization of Allele-Specific Regulation of Telomerase Reverse Transcriptase in Promoter Mutant Thyroid Cancer Cell Lines. Thyroid 2020; 30:1470-1481. [PMID: 32228178 PMCID: PMC7583328 DOI: 10.1089/thy.2020.0055] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Background: Telomerase reverse transcriptase (TERT) promoter mutations play a role in carcinogenesis and are found in both tumors and cancer cell lines. TERT promoter methylation, transcription factor binding, chromatin remodeling, and alternative splicing are also known to play an integral role in TERT regulation. Methods: Using nanopore Cas9 targeted sequencing, we characterized allele-specific methylation in thyroid cancer cell lines heterozygous for the TERT promoter mutation. Furthermore, using chromatin immunoprecipitation followed by Sanger sequencing, we probed allele-specific binding of the transcription factors GABPA (GA binding protein transcription factor subunit alpha) and MYC, as well as the chromatin marks H3K4me3 and H3K27me3. Finally, using coding single nucleotide polymorphisms and the long-read sequencing, we examined complementary DNA for monoallelic expression (MAE). Results: We found the mutant TERT promoter allele to be significantly less methylated than wild type, while more methylated in the gene body in heterozygous TERT mutant cell lines. We demonstrated that the transcriptional activators GABPA and MYC bind only to the mutant TERT allele. In addition, the activating and repressive chromatin marks H3K4me3 and H3K27me3, respectively, bind mutant and wild-type alleles exclusively. Finally, in heterozygous mutant cell lines, TERT exhibits MAE from the mutant allele only. Conclusions: In summary, by employing new long-read sequencing methods, we were able to definitively demonstrate allele-specific DNA methylation, histone modifications, transcription factor binding, and the resulting monoallelic transcription in cell lines with heterozygous TERT mutations.
Collapse
Affiliation(s)
- Brittany A. McKelvey
- Department of Surgery, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Department of Molecular Biology and Genetics, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Timothy Gilpatrick
- Department of Biomedical Engineering, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Yongchun Wang
- Department of Surgery, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Winston Timp
- Department of Molecular Biology and Genetics, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Department of Biomedical Engineering, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Christopher B. Umbricht
- Department of Surgery, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Department of Oncology, and The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Department of Pathology, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Martha A. Zeiger
- Surgical Oncology Program, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA
| |
Collapse
|
12
|
Rowland TJ, Bonham AJ, Cech TR. Allele-specific proximal promoter hypomethylation of the telomerase reverse transcriptase gene (TERT) associates with TERT expression in multiple cancers. Mol Oncol 2020; 14:2358-2374. [PMID: 33245585 PMCID: PMC7530785 DOI: 10.1002/1878-0261.12786] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 08/04/2020] [Accepted: 08/13/2020] [Indexed: 12/14/2022] Open
Abstract
Telomerase reverse transcriptase (TERT) is pathologically expressed in the vast majority of human cancers, but the epigenetic regulation of its expression is only beginning to be understood. In particular, the active TERT gene in cancer cells has been characterized as having a hypermethylated CpG island, opposite to the general association of DNA methylation with gene repression. Here, we analyzed TERT promoter CpG methylation in 833 human cancer cell lines representing 23 different tissue types and found hypermethylation of the upstream portion of the CpG island and more conserved hypomethylation of a region including the proximal TERT promoter and exon 1. In cell lines with monoallelic expression of TERT, we found allelic methylation of the proximal TERT promoter. This included cell lines with the -124 or -146 activating promoter mutation as well as wild-type TERT cancer lines. In these cell line types, decreased proximal promoter methylation is associated with the active allele. Compared to cells with monoallelic expression of TERT, lines with biallelic expression of TERT had even lower methylation in the proximal TERT promoter. Thus, in cell lines from cancers of many different tissues, the TERT proximal promoter has canonical DNA methylation, with low methylation correlating with increased TERT expression.
Collapse
Affiliation(s)
- Teisha J. Rowland
- Department of BiochemistryBioFrontiers InstituteUniversity of Colorado BoulderBoulderCOUSA
- Howard Hughes Medical InstituteUniversity of Colorado BoulderBoulderCOUSA
| | - Andrew J. Bonham
- Department of Chemistry & BiochemistryMetropolitan State University of DenverDenverCOUSA
| | - Thomas R. Cech
- Department of BiochemistryBioFrontiers InstituteUniversity of Colorado BoulderBoulderCOUSA
- Howard Hughes Medical InstituteUniversity of Colorado BoulderBoulderCOUSA
| |
Collapse
|
13
|
Modulation of telomerase expression and function by miRNAs: Anti-cancer potential. Life Sci 2020; 259:118387. [PMID: 32890603 DOI: 10.1016/j.lfs.2020.118387] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Revised: 08/24/2020] [Accepted: 08/30/2020] [Indexed: 12/11/2022]
Abstract
Telomerase is a nucleoprotein reverse transcriptase that maintains the telomere, a protective structure at the ends of the chromosome, and is active in cancer cells, stem cells, and fetal cells. Telomerase immortalizes cancer cells and induces unlimited cell division by preventing telomere shortening. Immortalized cancer cells have unlimited proliferative potential due to telomerase activity that causes tumorigenesis and malignancy. Therefore, telomerase can be a lucrative anti-cancer target. The regulation of catalytic subunit of telomerase (TERT) determines the extent of telomerase activity. miRNAs, as an endogenous regulator of gene expression, can control telomerase activity by targeting TERT mRNA. miRNAs that have a decreasing effect on TERT translation mediate modulation of telomerase activity in cancer cells by binding to TERT mRNA and regulating TERT translation. In this review, we provide an update on miRNAs that influence telomerase activity by regulation of TERT translation.
Collapse
|
14
|
Cangelosi D, Morini M, Zanardi N, Sementa AR, Muselli M, Conte M, Garaventa A, Pfeffer U, Bosco MC, Varesio L, Eva A. Hypoxia Predicts Poor Prognosis in Neuroblastoma Patients and Associates with Biological Mechanisms Involved in Telomerase Activation and Tumor Microenvironment Reprogramming. Cancers (Basel) 2020; 12:E2343. [PMID: 32825087 PMCID: PMC7563184 DOI: 10.3390/cancers12092343] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 08/09/2020] [Accepted: 08/17/2020] [Indexed: 12/23/2022] Open
Abstract
The biological and clinical heterogeneity of neuroblastoma (NB) demands novel biomarkers and therapeutic targets in order to drive the most appropriate treatment for each patient. Hypoxia is a condition of low-oxygen tension occurring in poorly vascularized tumor tissues. In this study, we aimed to assess the role of hypoxia in the pathogenesis of NB and at developing a new clinically relevant hypoxia-based predictor of outcome. We analyzed the gene expression profiles of 1882 untreated NB primary tumors collected at diagnosis and belonging to four existing data sets. Analyses took advantage of machine learning methods. We identified NB-hop, a seven-gene hypoxia biomarker, as a predictor of NB patient prognosis, which is able to discriminate between two populations of patients with unfavorable or favorable outcome on a molecular basis. NB-hop retained its prognostic value in a multivariate model adjusted for established risk factors and was able to additionally stratify clinically relevant groups of patients. Tumors with an unfavorable NB-hop expression showed a significant association with telomerase activation and a hypoxic, immunosuppressive, poorly differentiated, and apoptosis-resistant tumor microenvironment. NB-hop defines a new population of NB patients with hypoxic tumors and unfavorable prognosis and it represents a critical factor for the stratification and treatment of NB patients.
Collapse
Affiliation(s)
- Davide Cangelosi
- Laboratory of Molecular Biology, IRCCS Istituto Giannina Gaslini, 16147 Genova, Italy; (M.M.); (N.Z.); (L.V.); (A.E.)
| | - Martina Morini
- Laboratory of Molecular Biology, IRCCS Istituto Giannina Gaslini, 16147 Genova, Italy; (M.M.); (N.Z.); (L.V.); (A.E.)
| | - Nicolò Zanardi
- Laboratory of Molecular Biology, IRCCS Istituto Giannina Gaslini, 16147 Genova, Italy; (M.M.); (N.Z.); (L.V.); (A.E.)
| | - Angela Rita Sementa
- Laboratory of Pathology, IRCCS Istituto Giannina Gaslini, 16147 Genova, Italy;
| | - Marco Muselli
- Institute of Electronics, Computer and Telecommunication Engineering, Italian National Research Council, 16149 Genova, Italy;
| | - Massimo Conte
- Pediatric Oncology Unit, IRCCS Istituto Giannina Gaslini, 16147 Genova, Italy; (M.C.); (A.G.)
| | - Alberto Garaventa
- Pediatric Oncology Unit, IRCCS Istituto Giannina Gaslini, 16147 Genova, Italy; (M.C.); (A.G.)
| | - Ulrich Pfeffer
- Integrated Oncology Therapies Department, Molecular Pathology, IRCCS Ospedale Policlinico San Martino, 16132 Genova, Italy;
| | - Maria Carla Bosco
- Laboratory of Molecular Biology, IRCCS Istituto Giannina Gaslini, 16147 Genova, Italy; (M.M.); (N.Z.); (L.V.); (A.E.)
| | - Luigi Varesio
- Laboratory of Molecular Biology, IRCCS Istituto Giannina Gaslini, 16147 Genova, Italy; (M.M.); (N.Z.); (L.V.); (A.E.)
| | - Alessandra Eva
- Laboratory of Molecular Biology, IRCCS Istituto Giannina Gaslini, 16147 Genova, Italy; (M.M.); (N.Z.); (L.V.); (A.E.)
| |
Collapse
|
15
|
Tang S, Huang X, Wang X, Zhou X, Huang H, Qin L, Tao H, Wang Q, Tao Y. Vital and Distinct Roles of H2A.Z Isoforms in Hepatocellular Carcinoma. Onco Targets Ther 2020; 13:4319-4337. [PMID: 32547065 PMCID: PMC7244249 DOI: 10.2147/ott.s243823] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2019] [Accepted: 04/09/2020] [Indexed: 12/24/2022] Open
Abstract
Purpose H2A.Z is an oncogenic histone variant that is overexpressed in cancers. Two isoforms of H2A.Z, H2AFZ and H2AFV, are identical except for a three-amino acid difference. However, their isoform-specific functions remain unclear in cancer development. Thereby, this study aimed to investigate whether the two isoforms play distinct functions in hepatocarcinogenesis. Materials and Methods Expressions of H2A.Z isoforms in 116 paired hepatocellular cancerous and para-cancerous tissues were detected by employing qPCR. GEO and TCGA databases were used to probe expressions and prognostic value of the two H2A.Z isoforms. A comprehensive meta-analysis was conducted. Furthermore, co-expressed analysis of H2AFZ and H2AFV was performed by using cBioPortal database. H2A.Z binding genes from Chip-seq were intersected with H2A.Z isoforms co-expressed genes to perform functional annotations. Cell proliferation experiments from H2AFZ knockout HepG2 and BEL-7402 cells were implemented. Finally, RNA-seq was applied to analyse alternative splicing in H2AFZ knockout and wild-type cells. Results H2AFZ and H2AFV were both significantly upregulated (P < 0.01) in hepatocellular carcinoma and related to poor prognosis (P < 0.01). The two H2A.Z isoforms played vital roles in cell proliferation. It is also predicted that unique functions of H2AFV contain spindle midzone and microtubule, while H2AFZ is especially associated with RNA export and spliceosome. Further, devoid H2AFZ may restrain liver cancer cell proliferation and cause many alternative splicing events. Conclusion Both H2A.Z isoforms play vital and distinct roles in the occurrence and progression of liver cancer, which may pave a way for novel therapeutic applications for cancers in the future.
Collapse
Affiliation(s)
- Shaomei Tang
- The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, People's Republic of China
| | - Xiaoliang Huang
- Department of Gastrointestinal Surgery, Guangxi Medical University Cancer Hospital, Nanning, Guangxi 530021, People's Republic of China
| | - Xi Wang
- Center for Genomic and Personalized Medicine, Guangxi Medical University, Nanning, Guangxi, People's Republic of China
| | - Xianguo Zhou
- Department of Research, Guangxi Medical University Cancer Hospital, Nanning, Guangxi 530021, People's Republic of China
| | - Huan Huang
- Center for Genomic and Personalized Medicine, Guangxi Medical University, Nanning, Guangxi, People's Republic of China
| | - Liwen Qin
- Center for Genomic and Personalized Medicine, Guangxi Medical University, Nanning, Guangxi, People's Republic of China
| | - Hongyu Tao
- Center for Genomic and Personalized Medicine, Guangxi Medical University, Nanning, Guangxi, People's Republic of China
| | - Qiuyan Wang
- Center for Genomic and Personalized Medicine, Guangxi Medical University, Nanning, Guangxi, People's Republic of China.,Department of Research, Guangxi Medical University Cancer Hospital, Nanning, Guangxi 530021, People's Republic of China.,Guangxi Colleges and Universities Key Laboratory of Biological Molecular Medicine Research, Nanning, Guangxi, People's Republic of China
| | - Yuting Tao
- Center for Genomic and Personalized Medicine, Guangxi Medical University, Nanning, Guangxi, People's Republic of China.,Guangxi Key Laboratory for Genomic and Personalized Medicine, Guangxi, Collaborative Innovation Center for Genomic and Personalized Medicine, Nanning, Guangxi, People's Republic of China
| |
Collapse
|
16
|
Ferrucci L, Gonzalez‐Freire M, Fabbri E, Simonsick E, Tanaka T, Moore Z, Salimi S, Sierra F, de Cabo R. Measuring biological aging in humans: A quest. Aging Cell 2020; 19:e13080. [PMID: 31833194 PMCID: PMC6996955 DOI: 10.1111/acel.13080] [Citation(s) in RCA: 309] [Impact Index Per Article: 77.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Revised: 10/22/2019] [Accepted: 10/27/2019] [Indexed: 12/16/2022] Open
Abstract
The global population of individuals over the age of 65 is growing at an unprecedented rate and is expected to reach 1.6 billion by 2050. Most older individuals are affected by multiple chronic diseases, leading to complex drug treatments and increased risk of physical and cognitive disability. Improving or preserving the health and quality of life of these individuals is challenging due to a lack of well-established clinical guidelines. Physicians are often forced to engage in cycles of "trial and error" that are centered on palliative treatment of symptoms rather than the root cause, often resulting in dubious outcomes. Recently, geroscience challenged this view, proposing that the underlying biological mechanisms of aging are central to the global increase in susceptibility to disease and disability that occurs with aging. In fact, strong correlations have recently been revealed between health dimensions and phenotypes that are typical of aging, especially with autophagy, mitochondrial function, cellular senescence, and DNA methylation. Current research focuses on measuring the pace of aging to identify individuals who are "aging faster" to test and develop interventions that could prevent or delay the progression of multimorbidity and disability with aging. Understanding how the underlying biological mechanisms of aging connect to and impact longitudinal changes in health trajectories offers a unique opportunity to identify resilience mechanisms, their dynamic changes, and their impact on stress responses. Harnessing how to evoke and control resilience mechanisms in individuals with successful aging could lead to writing a new chapter in human medicine.
Collapse
Affiliation(s)
- Luigi Ferrucci
- Translational Gerontology BranchBiomedical Research CenterNational Institute on AgingNational Institutes of HealthBaltimoreMDUSA
| | - Marta Gonzalez‐Freire
- Translational Gerontology BranchBiomedical Research CenterNational Institute on AgingNational Institutes of HealthBaltimoreMDUSA
| | - Elisa Fabbri
- Translational Gerontology BranchBiomedical Research CenterNational Institute on AgingNational Institutes of HealthBaltimoreMDUSA
- Department of Medical and Surgical SciencesUniversity of BolognaBolognaItaly
| | - Eleanor Simonsick
- Translational Gerontology BranchBiomedical Research CenterNational Institute on AgingNational Institutes of HealthBaltimoreMDUSA
| | - Toshiko Tanaka
- Translational Gerontology BranchBiomedical Research CenterNational Institute on AgingNational Institutes of HealthBaltimoreMDUSA
| | - Zenobia Moore
- Translational Gerontology BranchBiomedical Research CenterNational Institute on AgingNational Institutes of HealthBaltimoreMDUSA
| | - Shabnam Salimi
- Department of Epidemiology and Public HealthUniversity of Maryland School of MedicineBaltimoreMDUSA
| | - Felipe Sierra
- Division of Aging BiologyNational Institute on AgingNIHBethesdaMDUSA
| | - Rafael de Cabo
- Translational Gerontology BranchBiomedical Research CenterNational Institute on AgingNational Institutes of HealthBaltimoreMDUSA
| |
Collapse
|
17
|
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.
Collapse
Affiliation(s)
- Joan Smith-Sonneborn
- Department Zoology and Physiology, University of Wyoming, Laramie, Wyoming, WY, USA
| |
Collapse
|
18
|
McKelvey BA, Umbricht CB, Zeiger MA. Telomerase Reverse Transcriptase (TERT) Regulation in Thyroid Cancer: A Review. Front Endocrinol (Lausanne) 2020; 11:485. [PMID: 32849278 PMCID: PMC7412884 DOI: 10.3389/fendo.2020.00485] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 06/22/2020] [Indexed: 12/17/2022] Open
Abstract
Telomerase reverse transcriptase (TERT) is the catalytic subunit of the enzyme telomerase and is essential for telomerase activity. Upregulation of TERT expression and resulting telomerase activity occurs in the large majority of malignancies, including thyroid cancer. This upregulation results in continued cellular proliferation and avoidance of cellular senescence and cell death. In this review we will briefly introduce TERT and telomerase activity as it pertains to thyroid cancer and, highlight the effects of TERT on cancer cells. We will also explore in detail the different TERT regulatory strategies and how TERT is reactivated in thyroid cancer cells, specifically. These regulatory mechanisms include both activating single base pair TERT promoter mutations and epigenetic changes at the promoter, including changes in CpG methylation and histone modifications that affect chromatin structure. Further, regulation includes the allele-specific regulation of the TERT promoter in thyroid cancer cells harboring the TERT promoter mutation. These entail allele-specific transcriptional activator binding, DNA methylation, histone modifications, and mono-allelic expression of TERT. Lastly, TERT copy number alterations and alternative splicing are also implicated. Both amplifications of the TERT locus and increased full-length transcripts and decreased inactive and dominant negative isoforms result in active telomerase. Finally, the clinical significance of TERT in thyroid cancer is also reviewed.
Collapse
Affiliation(s)
- Brittany A. McKelvey
- Department of Surgery, Johns Hopkins University School of Medicine, Baltimore, MD, United States
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Christopher B. Umbricht
- Department of Surgery, Johns Hopkins University School of Medicine, Baltimore, MD, United States
- Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, MD, United States
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Martha A. Zeiger
- Surgical Oncology Program, National Cancer Institute, National Institutes of Health, Bethesda, MD, United States
- *Correspondence: Martha A. Zeiger
| |
Collapse
|
19
|
Patrick M, Weng NP. Expression and regulation of telomerase in human T cell differentiation, activation, aging and diseases. Cell Immunol 2019; 345:103989. [PMID: 31558266 DOI: 10.1016/j.cellimm.2019.103989] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Revised: 09/18/2019] [Accepted: 09/18/2019] [Indexed: 12/15/2022]
Abstract
Telomeres are essential for chromosomal integrity. Telomere shortening during cell division restricts cellular proliferative capacity and leads to cellular senescence when critically shortened telomere lengths are reached. Similar to hematopoietic stem cells, T cells can upregulate telomerase activity to compensate for telomere loss incurred during proliferation in response to engagement of the T cell antigen receptor (TCR) or exposure to homeostatic cytokines. However, this compensation for telomere loss by telomerase in T cells is imperfect or limited, as shortening of T cell telomeres is observed in human aging and during in vitro longterm culture. In this review, we summarize the current state of knowledge regarding the expression and regulation of telomerase in human T cells and changes of telomerase expression during development, activation, differentiation, aging and disease conditions. In conclusion, we discuss how controlled enhancement of telomerase activity could be a potential strategy to improve T cell function in the elderly and in immunotherapy.
Collapse
Affiliation(s)
- Michael Patrick
- Laboratory of Molecular Biology and Immunology, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Nan-Ping Weng
- Laboratory of Molecular Biology and Immunology, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA.
| |
Collapse
|
20
|
Patrick MS, Cheng NL, Kim J, An J, Dong F, Yang Q, Zou I, Weng NP. Human T Cell Differentiation Negatively Regulates Telomerase Expression Resulting in Reduced Activation-Induced Proliferation and Survival. Front Immunol 2019; 10:1993. [PMID: 31497023 PMCID: PMC6712505 DOI: 10.3389/fimmu.2019.01993] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Accepted: 08/07/2019] [Indexed: 01/10/2023] Open
Abstract
Maintenance of telomeres is essential for preserving T cell proliferative responses yet the precise role of telomerase in human T cell differentiation, function, and aging is not fully understood. Here we analyzed human telomerase reverse transcriptase (hTERT) expression and telomerase activity in six T cell subsets from 111 human adults and found that levels of hTERT mRNA and telomerase activity had an ordered decrease from naïve (TN) to central memory (TCM) to effector memory (TEM) cells and were higher in CD4+ than their corresponding CD8+ subsets. This differentiation-related reduction of hTERT mRNA and telomerase activity was preserved after activation. Furthermore, the levels of hTERT mRNA and telomerase activity were positively correlated with the degree of activation-induced proliferation and survival of T cells in vitro. Partial knockdown of hTERT by an anti-sense oligo in naïve CD4+ cells led to a modest but significant reduction of cell proliferation. Finally, we found that activation-induced levels of telomerase activity in CD4+ TN and TCM cells were significantly lower in old than in young subjects. These findings reveal that hTERT/telomerase expression progressively declines during T cell differentiation and age-associated reduction of activation-induced expression of hTERT/telomerase mainly affects naïve CD4+ T cells and suggest that enhancing telomerase activity could be a strategy to improve T cell function in the elderly.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | - Nan-ping Weng
- Laboratory of Molecular Biology and Immunology, National Institute on Aging, National Institutes of Health, Baltimore, MD, United States
| |
Collapse
|
21
|
Avin BA, Wang Y, Gilpatrick T, Workman RE, Lee I, Timp W, Umbricht CB, Zeiger MA. Characterization of human telomerase reverse transcriptase promoter methylation and transcription factor binding in differentiated thyroid cancer cell lines. Genes Chromosomes Cancer 2019; 58:530-540. [PMID: 30664813 PMCID: PMC6621557 DOI: 10.1002/gcc.22735] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Revised: 01/04/2019] [Accepted: 01/14/2019] [Indexed: 12/27/2022] Open
Abstract
Telomerase reverse transcriptase (TERT) activation plays an important role in cancer development by enabling the immortalization of cells. TERT regulation is multifaceted, and its promoter methylation has been implicated in controlling expression through alteration in transcription factor binding. We have characterized TERT promoter methylation, transcription factor binding, and TERT expression levels in five differentiated thyroid cancer (DTC) cell lines and six normal thyroid tissue samples by targeted bisulfite sequencing, ChIP-qPCR, and qRT-PCR. DTC cell lines express varying levels of TERT and exhibit TERT promoter methylation patterns similar to patterns seen in other telomerase positive cancer cell lines. The minimal promoter immediately surrounding the transcription start site is hypomethylated, while further upstream portions show dense methylation. In contrast, the TERT promoter in normal thyroid tissue is largely unmethylated throughout and expresses TERT minimally. Transcription factor binding is also affected by TERT mutation status. The E-twenty-six (ETS) factor GABPA exhibits TERT binding in the TERT mutant DTC cells only, and allele-specific methylation patterns at the minimal promoter were observed as well, which may indicate allele-specific factor recruitment at the minimal promoter. Furthermore, we identified binding sites for activators MYC and GSC in the hypermethylated upstream region, pointing to its possible importance in TERT regulation. Overall, TERT expression and telomerase activity depend on the interplay of multiple regulatory mechanisms including TERT promoter methylation, mutation status, and recruitment of transcription factors. This work explores of the interplay between these regulatory mechanisms and offers insight into cellular control of active telomerase in human cancer.
Collapse
Affiliation(s)
- Brittany A. Avin
- Department of Surgery, Johns Hopkins University, Baltimore, MD, United States 21287
- Department of Molecular Biology and Genetics, Johns Hopkins University, Baltimore, MD, United States 21287
| | - Yongchun Wang
- Department of Surgery, Johns Hopkins University, Baltimore, MD, United States 21287
| | - Timothy Gilpatrick
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, United States 21287
| | - Rachael E. Workman
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, United States 21287
| | - Isac Lee
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, United States 21287
| | - Winston Timp
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, United States 21287
| | - Christopher B. Umbricht
- Department of Surgery, Johns Hopkins University, Baltimore, MD, United States 21287
- Department of Oncology, Johns Hopkins University, Baltimore, MD, United States 21287
- Department of Pathology, Johns Hopkins University, Baltimore, MD, United States 21287
| | - Martha A. Zeiger
- Department of Surgery, The University of Virginia School of Medicine, Charlottesville, VA 22908
| |
Collapse
|
22
|
Ma FC, He RQ, Lin P, Zhong JC, Ma J, Yang H, Hu XH, Chen G. Profiling of prognostic alternative splicing in melanoma. Oncol Lett 2019; 18:1081-1088. [PMID: 31423168 PMCID: PMC6607279 DOI: 10.3892/ol.2019.10453] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Accepted: 04/12/2019] [Indexed: 12/18/2022] Open
Abstract
Alternative splicing can lead to the coding of proteins that act as promoters of cancer, which is associated with the progression of cancer. However, to the best of our knowledge, no systematic survival analysis of alternative splicing in melanoma has previously been reported. The present study conducted an in-depth analysis of integrated alternative splicing events detected in 96 patients with melanoma using data obtained from The Cancer Genome Atlas. Prognostic models and an alternative splicing correlation network were built for patients with melanoma. A total of 41,446 mRNA splicing events were detected in 9,780 genes and 2,348 alternative splicing events were identified to be significantly associated with overall survival of patients with melanoma. Of all the events used in the prognostic model, the model with alternate terminator alternative splicing events exhibited the highest efficiency for evaluating the outcome of patients with melanoma, with an area under the curve of 0.902. The present study identified prognostic predictors for melanoma and revealed alternative splicing networks in melanoma that could indicate underlying mechanisms.
Collapse
Affiliation(s)
- Fu-Chao Ma
- Department of Medical Oncology, First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi 530021, P.R. China
| | - Rong-Quan He
- Department of Medical Oncology, First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi 530021, P.R. China
| | - Peng Lin
- Ultrasonics Division of Radiology Department, First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi 530021, P.R. China
| | - Jin-Cai Zhong
- Department of Medical Oncology, First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi 530021, P.R. China
| | - Jie Ma
- Department of Medical Oncology, First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi 530021, P.R. China
| | - Hong Yang
- Ultrasonics Division of Radiology Department, First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi 530021, P.R. China
| | - Xiao-Hua Hu
- Department of Medical Oncology, First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi 530021, P.R. China
| | - Gang Chen
- Department of Pathology, First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi 530021, P.R. China
| |
Collapse
|
23
|
Abstract
Telomeres are specialised structures at the end of linear chromosomes. They consist of tandem repeats of the hexanucleotide sequence TTAGGG, as well as a protein complex called shelterin. Together, they form a protective loop structure against chromosome fusion and degradation. Shortening or damage to telomeres and opening of the loop induce an uncapped state that triggers a DNA damage response resulting in senescence or apoptosis.Average telomere length, usually measured in human blood lymphocytes, was thought to be a biomarker for ageing, survival and mortality. However, it becomes obvious that regulation of telomere length is very complex and involves multiple processes. For example, the "end replication problem" during DNA replication as well as oxidative stress are responsible for the shortening of telomeres. In contrast, telomerase activity can potentially counteract telomere shortening when it is able to access and interact with telomeres. However, while highly active during development and in cancer cells, the enzyme is down-regulated in most human somatic cells with a few exceptions such as human lymphocytes. In addition, telomeres can be transcribed, and the transcription products called TERRA are involved in telomere length regulation.Thus, telomere length and their integrity are regulated at many different levels, and we only start to understand this process under conditions of increased oxidative stress, inflammation and during diseases as well as the ageing process.This chapter aims to describe our current state of knowledge on telomeres and telomerase and their regulation in order to better understand their role for the ageing process.
Collapse
|
24
|
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.
Collapse
|
25
|
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.
Collapse
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.
| |
Collapse
|
26
|
do Amaral GCLS, Planello AC, Borgato G, de Lima DG, Guimarães GN, Marques MR, de Souza AP. 5-Aza-CdR promotes partial MGMT demethylation and modifies expression of different genes in oral squamous cell carcinoma. Oral Surg Oral Med Oral Pathol Oral Radiol 2019; 127:425-432. [PMID: 30827853 DOI: 10.1016/j.oooo.2019.01.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Revised: 01/03/2019] [Accepted: 01/06/2019] [Indexed: 12/15/2022]
Abstract
OBJECTIVE Treatment strategies for oral squamous cell carcinoma (OSCC) vary, depending on the stage of diagnosis. Surgery and radiotherapy are options for localized lesions for stage I patients, whereas chemotherapy is the main treatment for metastatic OSCC. However, aggressive tumors can relapse, frequently causing death. In an attempt to address this, novel treatment protocols using drugs that alter the epigenetic profile have emerged as an alternative to control tumor growth and metastasis. Therefore, the objective in this study was to investigate the effect of the demethylating drug 5-aza-CdR in SCC9 OSCC cells. STUDY DESIGN SCC9 cells were treated with 5-Aza-CdR at concentrations of 0.3μM and 2μM for 24hours and 48hours. DNA methylation of the MGMT, BRCA1, APC, c-MYC, and hTERT genes were investigated by using the methylation-specific high-resolution melting technique. Real time-polymerase chain reaction and quantitative polymerase chain reaction were performed to analyze gene expression. RESULTS 5-Aza-CdR promoted demethylation of MGMT and modified the transcription of all analyzed genes. Curiously, 5-aza-CdR at the concentration of 0.3μM was more efficient than 2μM in SCC9 cells. CONCLUSIONS We observed that 5-aza-CdR led to MGMT demethylation, upregulated the transcription of 3 important tumor suppressor genes, and promoted the downregulation of c-Myc.
Collapse
Affiliation(s)
- Guilherme C L S do Amaral
- Laboratory of Molecular Biology, Department of Morphology, Piracicaba Dental School, FOP, State University of Campinas, UNICAMP, Piracicaba-SP, Brazil
| | - Aline C Planello
- Laboratory of Molecular Biology, Department of Morphology, Piracicaba Dental School, FOP, State University of Campinas, UNICAMP, Piracicaba-SP, Brazil
| | - Gabriell Borgato
- Laboratory of Molecular Biology, Department of Morphology, Piracicaba Dental School, FOP, State University of Campinas, UNICAMP, Piracicaba-SP, Brazil
| | - Dieila Giomo de Lima
- Laboratory of Molecular Biology, Department of Morphology, Piracicaba Dental School, FOP, State University of Campinas, UNICAMP, Piracicaba-SP, Brazil
| | - Gustavo N Guimarães
- Laboratory of Molecular Biology, Department of Morphology, Piracicaba Dental School, FOP, State University of Campinas, UNICAMP, Piracicaba-SP, Brazil
| | - Marcelo Rocha Marques
- Laboratory of Molecular Biology, Department of Morphology, Piracicaba Dental School, FOP, State University of Campinas, UNICAMP, Piracicaba-SP, Brazil
| | - Ana Paula de Souza
- Laboratory of Molecular Biology, Department of Morphology, Piracicaba Dental School, FOP, State University of Campinas, UNICAMP, Piracicaba-SP, Brazil.
| |
Collapse
|
27
|
Non-duplex G-Quadruplex Structures Emerge as Mediators of Epigenetic Modifications. Trends Genet 2018; 35:129-144. [PMID: 30527765 DOI: 10.1016/j.tig.2018.11.001] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Revised: 10/10/2018] [Accepted: 11/02/2018] [Indexed: 12/16/2022]
Abstract
The role of non-duplex DNA, the guanine-quadruplex structure in particular, is becoming widely appreciated. Increasing evidence in the last decade implicates quadruplexes in important processes such as transcription and replication. Interestingly, more recent work suggests roles for quadruplexes, in association with quadruplex-interacting proteins, in epigenetics through both DNA and histone modifications. Here, we review the effect of the quadruplex structure on post-replication epigenetic memory and quadruplex-induced promoter DNA/histone modifications. Furthermore, we highlight the epigenetic state of the telomerase promoter where quadruplexes could play a key regulatory role. Finally, we discuss the possibility that DNA structures such as quadruplexes, within a largely duplex DNA background, could act as molecular anchors for locally induced epigenetic modifications.
Collapse
|
28
|
Armstrong CA, Tomita K. Fundamental mechanisms of telomerase action in yeasts and mammals: understanding telomeres and telomerase in cancer cells. Open Biol 2018; 7:rsob.160338. [PMID: 28330934 PMCID: PMC5376709 DOI: 10.1098/rsob.160338] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Accepted: 02/20/2017] [Indexed: 12/12/2022] Open
Abstract
Aberrant activation of telomerase occurs in 85–90% of all cancers and underpins the ability of cancer cells to bypass their proliferative limit, rendering them immortal. The activity of telomerase is tightly controlled at multiple levels, from transcriptional regulation of the telomerase components to holoenzyme biogenesis and recruitment to the telomere, and finally activation and processivity. However, studies using cancer cell lines and other model systems have begun to reveal features of telomeres and telomerase that are unique to cancer. This review summarizes our current knowledge on the mechanisms of telomerase recruitment and activation using insights from studies in mammals and budding and fission yeasts. Finally, we discuss the differences in telomere homeostasis between normal cells and cancer cells, which may provide a foundation for telomere/telomerase targeted cancer treatments.
Collapse
Affiliation(s)
- Christine A Armstrong
- Chromosome Maintenance Group, UCL Cancer Institute, University College London, 72 Huntley Street, London WC1E 6DD, UK
| | - Kazunori Tomita
- Chromosome Maintenance Group, UCL Cancer Institute, University College London, 72 Huntley Street, London WC1E 6DD, UK
| |
Collapse
|
29
|
Fry EA, Inoue K. Aberrant expression of ETS1 and ETS2 proteins in cancer. CANCER REPORTS AND REVIEWS 2018; 2:10.15761/CRR.1000151. [PMID: 29974077 PMCID: PMC6027756 DOI: 10.15761/crr.1000151] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The ETS transcription factors regulate expression of genes involved in normal cell development, proliferation, differentiation, angiogenesis, and apoptosis, consisting of 28 family members in humans. Dysregulation of these transcription factors facilitates cell proliferation in cancers, and several members participate in invasion and metastasis by activating gene transcription. ETS1 and ETS2 are the founding members of the ETS family and regulate transcription by binding to ETS sequences. They are both involved in oncogenesis and tumor suppression depending on the biological situations used. The essential roles of ETS proteins in human telomere maintenance have been suggested, which have been linked to creation of new Ets binding sites. Recently, preferential binding of ETS2 to gain-of-function mutant p53 and ETS1 to wild type p53 (WTp53) has been suggested, raising the tumor promoting role for the former and tumor suppressive role for the latter. The oncogenic and tumor suppressive functions of ETS1 and 2 proteins have been discussed.
Collapse
Affiliation(s)
- Elizabeth A. Fry
- The Dept. of Pathology, Wake Forest University School of Medicine, Medical Center Blvd., Winston-Salem, NC 27157 USA
| | - Kazushi Inoue
- The Dept. of Pathology, Wake Forest University School of Medicine, Medical Center Blvd., Winston-Salem, NC 27157 USA
| |
Collapse
|
30
|
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.
Collapse
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.
| |
Collapse
|
31
|
KMT2A promotes melanoma cell growth by targeting hTERT signaling pathway. Cell Death Dis 2017; 8:e2940. [PMID: 28726783 PMCID: PMC5550845 DOI: 10.1038/cddis.2017.285] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Revised: 05/24/2017] [Accepted: 05/26/2017] [Indexed: 01/08/2023]
Abstract
Melanoma is an aggressive cutaneous malignancy, illuminating the exact mechanisms and finding novel therapeutic targets are urgently needed. In this study, we identified KMT2A as a potential target, which promoted the growth of human melanoma cells. KMT2A knockdown significantly inhibited cell viability and cell migration and induced apoptosis, whereas KMT2A overexpression effectively promoted cell proliferation in various melanoma cell lines. Further study showed that KMT2A regulated melanoma cell growth by targeting the hTERT-dependent signal pathway. Knockdown of KMT2A markedly inhibited the promoter activity and expression of hTERT, and hTERT overexpression rescued the viability inhibition caused by KMT2A knockdown. Moreover, KMT2A knockdown suppressed tumorsphere formation and the expression of cancer stem cell markers, which was also reversed by hTERT overexpression. In addition, the results from a xenograft mouse model confirmed that KMT2A promoted melanoma growth via hTERT signaling. Finally, analyses of clinical samples demonstrated that the expression of KMT2A and hTERT were positively correlated in melanoma tumor tissues, and KMT2A high expression predicted poor prognosis in melanoma patients. Collectively, our results indicate that KMT2A promotes melanoma growth by activating the hTERT signaling, suggesting that the KMT2A/hTERT signaling pathway may be a potential therapeutic target for melanoma.
Collapse
|
32
|
Kumar A, Nilednu P, Kumar A, Sharma NK. Epigenetic perturbation driving asleep telomerase reverse transcriptase: Possible therapeutic avenues in carcinoma. Tumour Biol 2017; 39:1010428317695951. [DOI: 10.1177/1010428317695951] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
In the last decade, implications of human telomerase reverse transcriptase (hTERT), a component of ribonucleoprotein telomerase in aging, senescence, and stem cell are highly evident. Besides, the activation of hTERT is also being documented several cancer types including carcinoma. The awakening of telomerase during carcinoma initiation and development is being seen with different perspectives including genetic and epigenetic tools and events. In view of several tumor progenitors genes (also referred as epigenetic mediators), telomerase is placed as key enzyme to achieve the carcinoma phenotype and sustain during the progression. It is true that swaying of telomerase in carcinoma could be facilitated with dedicated set of epigenetic modulators and modifiers players. These epigenetic alterations are heritable, potentially reversible, and seen as the epigenetic signature of carcinoma. Several papers converge to suggest that DNA methylation, histone modification, and small non-coding RNAs are the widely appreciated epigenetic changes towards hTERT modulation. In this review, we summarize the contribution of epigenetic factors in the telomerase activation and discuss potential avenues to achieve therapeutic intervention in carcinoma.
Collapse
Affiliation(s)
- Ajay Kumar
- Cancer and Translational Research Lab, Department of Biotechnology, Dr. D. Y. Patil Biotechnology & Bioinformatics Institute, Dr. D. Y. Patil Vidyapeeth, Pune, Pune, India
| | - Pritish Nilednu
- Cancer and Translational Research Lab, Department of Biotechnology, Dr. D. Y. Patil Biotechnology & Bioinformatics Institute, Dr. D. Y. Patil Vidyapeeth, Pune, Pune, India
| | - Azad Kumar
- Cancer and Translational Research Lab, Department of Biotechnology, Dr. D. Y. Patil Biotechnology & Bioinformatics Institute, Dr. D. Y. Patil Vidyapeeth, Pune, Pune, India
| | - Nilesh Kumar Sharma
- Cancer and Translational Research Lab, Department of Biotechnology, Dr. D. Y. Patil Biotechnology & Bioinformatics Institute, Dr. D. Y. Patil Vidyapeeth, Pune, Pune, India
| |
Collapse
|