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Li S, Hu G, Chen Y, Sang Y, Tang Q, Liu R. TERT upstream promoter methylation regulates TERT expression and acts as a therapeutic target in TERT promoter mutation-negative thyroid cancer. Cancer Cell Int 2024; 24:271. [PMID: 39097722 PMCID: PMC11297792 DOI: 10.1186/s12935-024-03459-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2024] [Accepted: 07/25/2024] [Indexed: 08/05/2024] Open
Abstract
BACKGROUND DNA hypermethylation and hotspot mutations were frequently observed in the upstream and core promoter of telomerase reverse transcriptase (TERT), respectively, and they were associated with increased TERT expression and adverse clinical outcomes in thyroid cancer. In TERT promoter mutant cancer cells, the hypomethylated TERT mutant allele was active and the hypermethylated TERT wild-type allele was silenced. However, whether and how the upstream promoter methylation regulates TERT expression in TERT mutation-negative cells were largely unknown. METHODS DNA demethylating agents 5-azacytidine and decitabine and a genomic locus-specific demethylation system based on dCas9-TET1 were used to assess the effects of TERT upstream promoter methylation on TERT expression, cell growth and apoptosis of thyroid cancer cells. Regulatory proteins binding to TERT promoter were identified by CRISPR affinity purification in situ of regulatory elements (CAPTURE) combined with mass spectrometry. The enrichments of selected regulatory proteins and histone modifications were evaluated by chromatin immunoprecipitation. RESULTS The level of DNA methylation at TERT upstream promoter and expression of TERT were significantly decreased after treatment with 5-azacytidine or decitabine in TERT promoter wild-type thyroid cancer cells. Genomic locus-specific demethylation of TERT upstream promoter induced TERT downregulation, along with cell apoptosis and growth inhibition. Consistently, demethylating agents sharply inhibited the growth of thyroid cancer cells harboring hypermethylated TERT but had little effect on cells with TERT hypomethylation. Moreover, we identified that the chromatin remodeling protein CHD4 binds to methylated TERT upstream promoter and promotes its transcription by suppressing the enrichment of H3K9me3 and H3K27me3 at TERT promoter. CONCLUSIONS This study uncovered the mechanism of promoter methylation mediated TERT activation in TERT promoter mutation-negative thyroid cancer cells and indicated TERT upstream promoter methylation as a therapeutic target for thyroid cancer.
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Affiliation(s)
- Shiyong Li
- Institute of Precision Medicine, The First Affiliated Hospital, Sun Yat-sen University, No. 58, Zhongshan Second Road, Guangzhou, Guangdong, 510080, China
| | - Guanghui Hu
- Institute of Precision Medicine, The First Affiliated Hospital, Sun Yat-sen University, No. 58, Zhongshan Second Road, Guangzhou, Guangdong, 510080, China
| | - Yulu Chen
- Institute of Precision Medicine, The First Affiliated Hospital, Sun Yat-sen University, No. 58, Zhongshan Second Road, Guangzhou, Guangdong, 510080, China
| | - Ye Sang
- Institute of Precision Medicine, The First Affiliated Hospital, Sun Yat-sen University, No. 58, Zhongshan Second Road, Guangzhou, Guangdong, 510080, China
| | - Qin Tang
- Institute of Precision Medicine, The First Affiliated Hospital, Sun Yat-sen University, No. 58, Zhongshan Second Road, Guangzhou, Guangdong, 510080, China
| | - Rengyun Liu
- Institute of Precision Medicine, The First Affiliated Hospital, Sun Yat-sen University, No. 58, Zhongshan Second Road, Guangzhou, Guangdong, 510080, China.
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Abstract
DNA methylation is considered an essential epigenetic event during leukaemogenesis and the emergence of drug resistance, which is primarily regulated by DNA methyltransferases. DNA methyltransferase-1 (DNMT1) is one of the members of DNA methyltransferases, in charge of maintaining established methylation. Recently, DNMT1 is shown to promote malignant events of cancers through the epigenetic and non-epigenetic processes. Increasing studies in solid tumours have identified DNMT1 as a therapeutic target and a regulator of therapy resistance; however, it is unclear whether DNMT1 is a critical regulator in acute myeloid leukaemia (AML) and how it works. In this review, we summarized the recent understanding of DNMT1 in normal haematopoiesis and AML and discussed the possible functions of DNMT1 in promoting the development of AML and predicting the sensitivity of hypomethylation agents to better understand the relationship between DNMT1 and AML and to look for new hope to treat AML patients.Key messagesThe function of DNA methyltransferase-1 in acute myeloid leukaemia.DNA methyltransferase-1 predicts the sensitivity of drug and involves the emergence of drug resistance.
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Affiliation(s)
- Mengyuan Li
- Department of Hematology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, P.R. China
| | - Donghua Zhang
- Department of Hematology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, P.R. China
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3
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Stögbauer L, Thomas C, Wagner A, Warneke N, Bunk EC, Grauer O, Canisius J, Paulus W, Stummer W, Senner V, Brokinkel B. Efficacy of decitabine in malignant meningioma cells: relation to promoter demethylation of distinct tumor suppressor and oncogenes and independence from TERT. J Neurosurg 2021; 135:845-854. [PMID: 33307532 DOI: 10.3171/2020.7.jns193097] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Accepted: 07/06/2020] [Indexed: 11/06/2022]
Abstract
OBJECTIVE Chemotherapeutic options for meningiomas refractory to surgery or irradiation are largely unknown. Human telomerase reverse transcriptase (hTERT) promoter methylation with subsequent TERT expression and telomerase activity, key features in oncogenesis, are found in most high-grade meningiomas. Therefore, the authors investigated the impact of the demethylating agent decitabine (5-aza-2'-deoxycytidine) on survival and DNA methylation in meningioma cells. METHODS hTERT promoter methylation, telomerase activity, TERT expression, and cell viability and proliferation were investigated prior to and after incubation with decitabine in two benign (HBL-52 and Ben-Men 1) and one malignant (IOMM-Lee) meningioma cell line. The global effects of decitabine on DNA methylation were additionally explored with DNA methylation profiling. RESULTS High levels of TERT expression, telomerase activity, and hTERT promoter methylation were found in IOMM-Lee and Ben-Men 1 but not in HBL-52 cells. Decitabine induced a dose-dependent significant decrease of proliferation and viability after incubation with doses from 1 to 10 μM in IOMM-Lee but not in HBL-52 or Ben-Men 1 cells. However, effects in IOMM-Lee cells were not related to TERT expression, telomerase activity, or hTERT promoter methylation. Genome-wide methylation analyses revealed distinct demethylation of 14 DNA regions after drug administration in the decitabine-sensitive IOMM-Lee but not in the decitabine-resistant HBL-52 cells. Differentially methylated regions covered promoter regions of 11 genes, including several oncogenes and tumor suppressor genes that to the authors' knowledge have not yet been described in meningiomas. CONCLUSIONS Decitabine decreases proliferation and viability in high-grade but not in benign meningioma cell lines. The effects of decitabine are TERT independent but related to DNA methylation changes of promoters of distinct tumor suppressor genes and oncogenes.
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Affiliation(s)
| | | | | | | | | | - Oliver Grauer
- 3Department of Neurology, University Hospital Münster, North Rhine-Westphalia, Germany
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4
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Mechanism of Human Telomerase Reverse Transcriptase ( hTERT) Regulation and Clinical Impacts in Leukemia. Genes (Basel) 2021; 12:genes12081188. [PMID: 34440361 PMCID: PMC8392866 DOI: 10.3390/genes12081188] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 05/09/2021] [Accepted: 05/17/2021] [Indexed: 01/03/2023] Open
Abstract
The proliferative capacity and continuous survival of cells are highly dependent on telomerase expression and the maintenance of telomere length. For this reason, elevated expression of telomerase has been identified in virtually all cancers, including leukemias; however, it should be noted that expression of telomerase is sometimes observed later in malignant development. This time point of activation is highly dependent on the type of leukemia and its causative factors. Many recent studies in this field have contributed to the elucidation of the mechanisms by which the various forms of leukemias increase telomerase activity. These include the dysregulation of telomerase reverse transcriptase (TERT) at various levels which include transcriptional, post-transcriptional, and post-translational stages. The pathways and biological molecules involved in these processes are also being deciphered with the advent of enabling technologies such as next-generation sequencing (NGS), ribonucleic acid sequencing (RNA-Seq), liquid chromatography-mass spectrometry (LCMS/MS), and many others. It has also been established that TERT possess diagnostic value as most adult cells do not express high levels of telomerase. Indeed, studies have shown that prognosis is not favorable in patients who have leukemias expressing high levels of telomerase. Recent research has indicated that targeting of this gene is able to control the survival of malignant cells and therefore offers a potential treatment for TERT-dependent leukemias. Here we review the mechanisms of hTERT regulation and deliberate their association in malignant states of leukemic cells. Further, we also cover the clinical implications of this gene including its use in diagnostic, prognostic, and therapeutic discoveries.
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Park JW, Sahm F, Steffl B, Arrillaga-Romany I, Cahill D, Monje M, Herold-Mende C, Wick W, Turcan Ş. TERT and DNMT1 expression predict sensitivity to decitabine in gliomas. Neuro Oncol 2021; 23:76-87. [PMID: 32882013 DOI: 10.1093/neuonc/noaa207] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Decitabine (DAC) is an FDA-approved DNA methyltransferase (DNMT) inhibitor that is used in the treatment of patients with myelodysplastic syndromes. Previously, we showed that DAC marks antitumor activity against gliomas with isocitrate dehydrogenase 1 (IDH1) mutations. Based on promising preclinical results, a clinical trial has been launched to determine the effect of DAC in IDH-mutant gliomas. The next step is to comprehensively assess the efficacy and potential determinants of response to DAC in malignant gliomas. METHODS The expression and activity of telomerase reverse transcriptase (TERT) and DNMT1 were manipulated in patient-derived IDH1-mutant and -wildtype glioma lines, followed by assessment of cell proliferation with DAC treatment alone or in combination with telomerase inhibitors. RNA sequencing, Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment, and correlation analysis were performed. RESULTS IDH1-mutant glioma tumorspheres with hemizygous codeletion of chromosome arms 1p/19q were particularly sensitive to DAC and showed significant inhibition of DNA replication genes. Our transcriptome analysis revealed that DAC induced expression of cyclin-dependent kinase inhibitor 1A/p21 (CDKN1A), along with downregulation of TERT. These molecular changes were also observed following doxorubicin treatment, supporting the importance of DAC-induced DNA damage in contributing to this effect. We demonstrated that knockdown of p21 led to TERT upregulation. Strikingly, TERT overexpression increased DNMT1 levels and DAC sensitivity via a telomerase-independent mechanism. Furthermore, RNA inhibition (RNAi) targeting of DNMT1 abrogated DAC response in TERT-proficient glioma cells. CONCLUSIONS DAC downregulates TERT through p21 induction. Our data point to TERT and DNMT1 levels as potential determinants of response to DAC treatment.
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Affiliation(s)
- Jong-Whi Park
- Neurology Clinic and National Center for Tumor Diseases, University Hospital Heidelberg, Heidelberg, Germany
| | - Felix Sahm
- Department of Neuropathology, Institute of Pathology, University Hospital Heidelberg, Heidelberg, Germany.,Neuropathology, Clinical Cancer Research Consortium, Clinical Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Bianca Steffl
- Neurology Clinic and National Center for Tumor Diseases, University Hospital Heidelberg, Heidelberg, Germany
| | | | - Daniel Cahill
- Department of Neurosurgery, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Michelle Monje
- Department of Neurology and Neurological Sciences, Stanford University, Stanford, California, USA
| | - Christel Herold-Mende
- Division of Experimental Neurosurgery, Department of Neurosurgery, University of Heidelberg, Heidelberg, Germany
| | - Wolfgang Wick
- Neurology Clinic and National Center for Tumor Diseases, University Hospital Heidelberg, Heidelberg, Germany.,Clinical Cooperation Unit Neuro-oncology, German Consortium for Translational Cancer Research, DKFZ, Heidelberg, Germany
| | - Şevin Turcan
- Neurology Clinic and National Center for Tumor Diseases, University Hospital Heidelberg, Heidelberg, Germany
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Chebly A, Ropio J, Peloponese JM, Poglio S, Prochazkova-Carlotti M, Cherrier F, Ferrer J, Idrissi Y, Segal-Bendirdjian E, Chouery E, Farra C, Pham-Ledard A, Beylot-Barry M, Philippe Merlio J, Tomb R, Chevret E. Exploring hTERT promoter methylation in cutaneous T-cell lymphomas. Mol Oncol 2021; 16:1931-1946. [PMID: 33715271 PMCID: PMC9067155 DOI: 10.1002/1878-0261.12946] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2020] [Revised: 02/28/2021] [Accepted: 03/12/2021] [Indexed: 11/11/2022] Open
Abstract
Cutaneous T‐cell lymphomas (CTCLs) are telomerase‐positive tumors expressing hTERT, although neither gene rearrangement/amplification nor promoter hotspot mutations could explain the hTERT re‐expression. As the hTERT promoter is rich in CpG, we investigated the contribution of epigenetic mechanisms in its re‐expression. We analyzed hTERT promoter methylation status in CTCL cells compared with healthy cells. Gene‐specific methylation analyses revealed a common methylation pattern exclusively in tumor cells. This methylation pattern encompassed a hypermethylated distal region from −650 to −150 bp and a hypomethylated proximal region from −150 to +150 bp. Interestingly, the hypermethylated region matches with the recently named TERT hypermethylated oncogenic region (THOR). THOR has been associated with telomerase reactivation in many cancers, but it has so far not been reported in cutaneous lymphomas. Additionally, we assessed the effect of THOR on two histone deacetylase inhibitors (HDACi), romidepsin and vorinostat, both approved for CTCL treatment and a DNA methyltransferase inhibitor (DNMTi) 5‐azacytidine, unapproved for CTCL. Contrary to our expectations, the findings reported herein revealed that THOR methylation is relatively stable under these epigenetic drugs' pressure, whereas these drugs reduced the hTERT gene expression.
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Affiliation(s)
- Alain Chebly
- Univ. Bordeaux, INSERM, BaRITOn, U1053, F-33000, Bordeaux, France.,Saint Joseph University, Faculty of Medicine, Medical Genetics Unit (UGM), Beirut, Lebanon
| | - Joana Ropio
- Univ. Bordeaux, INSERM, BaRITOn, U1053, F-33000, Bordeaux, France.,Porto University, Institute of Biomedical Sciences of Abel Salazar, Instituto de Investigação e Inovação em Saúde, Institute of Molecular Pathology and Immunology (Ipatimup), Cancer Biology group, 4200-465, Porto, Portugal
| | - Jean-Marie Peloponese
- University of Montpellier, CNRS, IRIM-UMR 9004, Research Institute in Infectiology of Montpellier, Montpellier, France
| | - Sandrine Poglio
- Univ. Bordeaux, INSERM, BaRITOn, U1053, F-33000, Bordeaux, France
| | | | | | - Jacky Ferrer
- Univ. Bordeaux, INSERM, BaRITOn, U1053, F-33000, Bordeaux, France
| | - Yamina Idrissi
- Univ. Bordeaux, INSERM, BaRITOn, U1053, F-33000, Bordeaux, France
| | - Evelyne Segal-Bendirdjian
- INSERM, UMR-S 1124, Team: Cellular Homeostasis Cancer and Therapies, Université de Paris, Paris, France
| | - Eliane Chouery
- Saint Joseph University, Faculty of Medicine, Medical Genetics Unit (UGM), Beirut, Lebanon.,Department of Human Genetics, Gilbert and Rose-Marie Chagoury School of Medicine, Lebanese American University, Byblos, Lebanon
| | - Chantal Farra
- Saint Joseph University, Faculty of Medicine, Medical Genetics Unit (UGM), Beirut, Lebanon.,Hotel Dieu de France Medical Center, Faculty of Medicine, Genetics Department, Beirut, Lebanon
| | - Anne Pham-Ledard
- Univ. Bordeaux, INSERM, BaRITOn, U1053, F-33000, Bordeaux, France.,Bordeaux University Hospital Center, Dermatology Department, F-33000, Bordeaux, France
| | - Marie Beylot-Barry
- Univ. Bordeaux, INSERM, BaRITOn, U1053, F-33000, Bordeaux, France.,Bordeaux University Hospital Center, Dermatology Department, F-33000, Bordeaux, France
| | - Jean Philippe Merlio
- Univ. Bordeaux, INSERM, BaRITOn, U1053, F-33000, Bordeaux, France.,Bordeaux University Hospital Center, Tumor Bank and Tumor Biology Laboratory, F-33600, Pessac, France
| | - Roland Tomb
- Saint Joseph University, Faculty of Medicine, Medical Genetics Unit (UGM), Beirut, Lebanon.,Saint Joseph University, Faculty of Medicine, Dermatology Department, Beirut, Lebanon
| | - Edith Chevret
- Univ. Bordeaux, INSERM, BaRITOn, U1053, F-33000, Bordeaux, France
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7
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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: 26] [Impact Index Per Article: 5.2] [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.
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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
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8
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Ackermann S, Fischer M. Telomere Maintenance in Pediatric Cancer. Int J Mol Sci 2019; 20:E5836. [PMID: 31757062 PMCID: PMC6928840 DOI: 10.3390/ijms20235836] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Revised: 11/15/2019] [Accepted: 11/18/2019] [Indexed: 02/06/2023] Open
Abstract
Telomere length has been proposed as a biomarker of biological age and a risk factor for age-related diseases and cancer. Substantial progress has been made in recent decades in understanding the complex molecular relationships in this research field. However, the majority of telomere studies have been conducted in adults. The data on telomere dynamics in pediatric cancers is limited, and interpretation can be challenging, especially in cases where results are contrasting to those in adult entities. This review describes recent advances in the molecular characterization of structure and function of telomeres, regulation of telomerase activity in cancer pathogenesis in general, and highlights the key advances that have expanded our views on telomere biology in pediatric cancer, with special emphasis on the central role of telomere maintenance in neuroblastoma. Furthermore, open questions in the field of telomere maintenance research are discussed in the context of recently published literature.
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Affiliation(s)
- Sandra Ackermann
- Department of Experimental Pediatric Oncology, University Children’s Hospital of Cologne, Faculty of Medicine and University Hospital of Cologne, Kerpener Straße 62, 50937 Cologne, Germany
- Center for Molecular Medicine Cologne (CMMC), University of Cologne, Robert-Koch-Straße 21, 50931 Cologne, Germany
| | - Matthias Fischer
- Department of Experimental Pediatric Oncology, University Children’s Hospital of Cologne, Faculty of Medicine and University Hospital of Cologne, Kerpener Straße 62, 50937 Cologne, Germany
- Center for Molecular Medicine Cologne (CMMC), University of Cologne, Robert-Koch-Straße 21, 50931 Cologne, Germany
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9
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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: 3.5] [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.
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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
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10
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Yu W, Qin X, Jin Y, Li Y, Santiskulvong C, Vu V, Zeng G, Zhang Z, Chow M, Rao J. Tianshengyuan-1 (TSY-1) regulates cellular Telomerase activity by methylation of TERT promoter. Oncotarget 2018; 8:7977-7988. [PMID: 28002788 PMCID: PMC5352375 DOI: 10.18632/oncotarget.13939] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Accepted: 11/24/2016] [Indexed: 01/11/2023] Open
Abstract
Telomere and Telomerase have recently been explored as anti-aging and anti-cancer drug targets with only limited success. Previously we showed that the Chinese herbal medicine Tianshengyuan-1 (TSY-1), an agent used to treat bone marrow deficiency, has a profound effect on stimulating Telomerase activity in hematopoietic cells. Here, the mechanism of TSY-1 on cellular Telomerase activity was further investigated using HL60, a promyelocytic leukemia cell line, normal peripheral blood mononuclear cells, and CD34+ hematopoietic stem cells derived from umbilical cord blood. TSY-1 increases Telomerase activity in normal peripheral blood mononuclear cells and CD34+ hematopoietic stem cells with innately low Telomerase activity but decreases Telomerase activity in HL60 cells with high intrinsic Telomerase activity, both in a dose-response manner. Gene profiling analysis identified Telomerase reverse transcriptase (TERT) as the potential target gene associated with the TSY-1 effect, which was verified by both RT-PCR and western blot analysis. The β-galactosidase reporter staining assay showed that the effect of TSY-1 on Telomerase activity correlates with cell senescence. TSY-1 induced hypomethylation within TERT core promoter in HL60 cells but induced hypermethylation within TERT core promoter in normal peripheral blood mononuclear cells and CD34+ hematopoietic stem cells. TSY-1 appears to affect the Telomerase activity in different cell lines differently and the effect is associated with TERT expression, possibly via the methylation of TERT promoter.
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Affiliation(s)
- Weibo Yu
- Department of Pathology and Laboratory Medicine, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA, USA
| | - Xiaotian Qin
- Beijing Boyuantaihe Biological Technology Co., Ltd., Beijing, China
| | - Yusheng Jin
- Department of Pathology and Laboratory Medicine, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA, USA
| | - Yawei Li
- Beijing Boyuantaihe Biological Technology Co., Ltd., Beijing, China
| | | | - Victor Vu
- Department of Pathology and Laboratory Medicine, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA, USA
| | - Gang Zeng
- Department of Urology, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA, USA.,Jonsson Comprehensive Cancer Center, University of California at Los Angeles, Los Angeles, CA, USA
| | - Zuofeng Zhang
- Department of Epidemiology, School of Public Health, University of California at Los Angeles, Los Angeles, CA, USA
| | - Michelle Chow
- Department of Pathology and Laboratory Medicine, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA, USA
| | - Jianyu Rao
- Department of Pathology and Laboratory Medicine, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA, USA.,Jonsson Comprehensive Cancer Center, University of California at Los Angeles, Los Angeles, CA, USA
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11
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Takasawa K, Arai Y, Yamazaki-Inoue M, Toyoda M, Akutsu H, Umezawa A, Nishino K. DNA hypermethylation enhanced telomerase reverse transcriptase expression in human-induced pluripotent stem cells. Hum Cell 2017; 31:78-86. [PMID: 29103143 DOI: 10.1007/s13577-017-0190-x] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Accepted: 10/26/2017] [Indexed: 02/06/2023]
Abstract
During reprogramming into human induced pluripotent stem cells (iPSCs), several stem cell marker genes are induced, such as OCT-4, NANOG, SALL4, and TERT. OCT-4, NANOG, and SALL4 gene expression can be regulated by DNA methylation. Their promoters become hypomethylated in iPSCs during reprogramming, leading to their induced expression. However, epigenetic regulation of the TERT gene remains unclear. In this study, we focused on epigenetic regulation of the human TERT gene and identified a differentially methylated region (DMR) at a distal region in the TERT promoter between human iPSCs and their parental somatic cells. Interestingly, the TERT-DMR was highly methylated in iPSCs, but low-level methylation was observed in their parental somatic cells. Region-specific, methylated-promoter assays showed that the methylated TERT-DMR up-regulated the promoter activity in iPSCs. In addition, Lamin B1 accumulated at the TERT-DMR in iPSCs, but not in their parent somatic cells. These results suggested that the TERT transcription was enhanced by DNA methylation at the TERT-DMR via binding to nuclear lamina during reprogramming. Our findings shed light on a new functional aspect of DNA methylation in gene expression.
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Affiliation(s)
- Ken Takasawa
- Laboratory of Veterinary Biochemistry and Molecular Biology, Graduate School of Medicine and Veterinary Medicine/Faculty of Agriculture, University of Miyazaki, 1-1 Gakuen-Kibanadai-Nishi, Miyazaki, 889-2192, Japan
| | - Yoshikazu Arai
- Laboratory of Veterinary Biochemistry and Molecular Biology, Graduate School of Medicine and Veterinary Medicine/Faculty of Agriculture, University of Miyazaki, 1-1 Gakuen-Kibanadai-Nishi, Miyazaki, 889-2192, Japan
| | - Mayu Yamazaki-Inoue
- Center for Regenerative Medicine, National Research Institute for Child Health and Development, 2-10-1 Okura, Setagaya-ku, Tokyo, 157-8535, Japan
| | - Masashi Toyoda
- Research Team for Geriatric Medicine (Vascular Medicine), Tokyo Metropolitan Institute of Gerontology, 35-2 Sakaemachi, Itabashi-ku, Tokyo, 173-0015, Japan
| | - Hidenori Akutsu
- Center for Regenerative Medicine, National Research Institute for Child Health and Development, 2-10-1 Okura, Setagaya-ku, Tokyo, 157-8535, Japan
| | - Akihiro Umezawa
- Center for Regenerative Medicine, National Research Institute for Child Health and Development, 2-10-1 Okura, Setagaya-ku, Tokyo, 157-8535, Japan
| | - Koichiro Nishino
- Laboratory of Veterinary Biochemistry and Molecular Biology, Graduate School of Medicine and Veterinary Medicine/Faculty of Agriculture, University of Miyazaki, 1-1 Gakuen-Kibanadai-Nishi, Miyazaki, 889-2192, Japan. .,Center for Animal Disease Control, University of Miyazaki, 1-1 Gakuen-Kibanadai-Nishi, Miyazaki, 889-2192, Japan.
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12
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Abstract
PURPOSE OF REVIEW Adverse karyotype acute myeloid leukemia is a disease particularly of older patients, but also observed in younger patients. Despite all efforts, standard chemotherapy is still generally applied in fit patients, as already for decades, and for nearly all different subtypes of acute myeloid leukemia. Lack of more specifically targeted therapy and the often older age of the patients are complicating treatment, and in the subgroup of patients achieving a complete remission, the strikingly high frequency of relapse is a characteristic of this disease. This review aims to give an overview of current treatment approaches as well as emerging therapies. RECENT FINDINGS Currently, the approach of a targeted therapy specific to the genetic and/or epigenetic aberrations detected in the individual patient is still not possible, and a 'one treatment fits all' course of action is still used, with allografting as curative consolidation. However, first immunotherapeutic approaches are emerging as treatment options and first phase 1 and 2 studies are described. SUMMARY Treatment of acute myeloid leukemia with adverse karyotype is still not individualized, most treatment options currently not being curative. This can change in the near future, but recent findings will have to be implemented into larger phase 3 studies before being standard of care.
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GATA2 regulates the erythropoietin receptor in t(12;21) ALL. Oncotarget 2017; 8:66061-66074. [PMID: 29029492 PMCID: PMC5630392 DOI: 10.18632/oncotarget.19792] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Accepted: 06/26/2017] [Indexed: 01/27/2023] Open
Abstract
The t(12;21) (p13;q22) chromosomal translocation resulting in the ETV6/RUNX1 fusion gene is the most frequent structural cytogenetic abnormality in children with acute lymphoblastic leukemia (ALL). The erythropoietin receptor (EPOR), usually associated with erythroid progenitor cells, is highly expressed in ETV6/RUNX1 positive cases compared to other B-lineage ALL subtypes. Gene expression analysis of a microarray database and direct quantitative analysis of patient samples revealed strong correlation between EPOR and GATA2 expression in ALL, and higher expression of GATA2 in t(12;21) patients. The mechanism of EPOR regulation was mainly investigated using two B-ALL cell lines: REH, which harbor and express the ETV6/RUNX1 fusion gene; and NALM-6, which do not. Expression of EPOR was increased in REH cells compared to NALM-6 cells. Moreover, of the six GATA family members only GATA2 was differentially expressed with substantially higher levels present in REH cells. GATA2 was shown to bind to the EPOR 5'-UTR in REH, but did not bind in NALM-6 cells. Overexpression of GATA2 led to an increase in EPOR expression in REH cells only, indicating that GATA2 regulates EPOR but is dependent on the cellular context. Both EPOR and GATA2 are hypomethylated and associated with increased mRNA expression in REH compared to NALM-6 cells. Decitabine treatment effectively reduced methylation of CpG sites in the GATA2 promoter leading to increased GATA2 expression in both cell lines. Although Decitabine also reduced an already low level of methylation of the EPOR in NALM-6 cells there was no increase in EPOR expression. Furthermore, EPOR and GATA2 are regulated post-transcriptionally by miR-362 and miR-650, respectively. Overall our data show that EPOR expression in t(12;21) B-ALL cells, is regulated by GATA2 and is mediated through epigenetic, transcriptional and post-transcriptional mechanisms, contingent upon the genetic subtype of the disease.
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14
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Avin BA, Umbricht CB, Zeiger MA. Human telomerase reverse transcriptase regulation by DNA methylation, transcription factor binding and alternative splicing (Review). Int J Oncol 2016; 49:2199-2205. [PMID: 27779655 DOI: 10.3892/ijo.2016.3743] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2016] [Accepted: 10/17/2016] [Indexed: 12/31/2022] Open
Abstract
The catalytic subunit of telomerase, human telomerase reverse transcriptase (hTERT), plays an essential role in telomere maintenance to oppose cellular senescence and, is highly regulated in normal and cancerous cells. Regulation of hTERT occurs through multiple avenues, including a unique pattern of CpG promoter methylation and alternative splicing. Promoter methylation affects the binding of transcription factors, resulting in changes in expression of the gene. In addition to expression level changes, changes in promoter binding can affect alternative splicing in a cotranscriptional manner. The alternative splicing of hTERT results in either the full length transcript which can form the active telomerase complex with hTR, or numerous inactive isoforms. Both regulation strategies are exploited in cancer to activate telomerase, however, the exact mechanism is unknown. Therefore, unraveling the link between promoter methylation status and alternative splicing for hTERT could expose yet another level of hTERT regulation. In an attempt to provide insight into the cellular control of active telomerase in cancer, this review will discuss our current perspective on CpG methylation of the hTERT promoter region, summarize the different forms of alternatively spliced variants, and examine examples of transcription factor binding that affects splicing.
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Affiliation(s)
- Brittany A Avin
- Department of Surgery, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Christopher B Umbricht
- Department of Surgery, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Martha A Zeiger
- Department of Surgery, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
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15
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Ropio J, Merlio JP, Soares P, Chevret E. Telomerase Activation in Hematological Malignancies. Genes (Basel) 2016; 7:genes7090061. [PMID: 27618103 PMCID: PMC5039560 DOI: 10.3390/genes7090061] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Revised: 07/15/2016] [Accepted: 07/29/2016] [Indexed: 12/18/2022] Open
Abstract
Telomerase expression and telomere maintenance are critical for cell proliferation and survival, and they play important roles in development and cancer, including hematological malignancies. Transcriptional regulation of the rate-limiting subunit of human telomerase reverse transcriptase gen (hTERT) is a complex process, and unveiling the mechanisms behind its reactivation is an important step for the development of diagnostic and therapeutic applications. Here, we review the main mechanisms of telomerase activation and the associated hematologic malignancies.
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Affiliation(s)
- Joana Ropio
- Cutaneous Lymphoma Oncogenesis Team INSERM U1053 Bordeaux Research in Translational Oncology, Bordeaux University, Bordeaux 33076, France.
- Institute of Biomedical Sciences of Abel Salazar, University of Porto, Porto 4050-313, Portugal.
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto 4200-135, Portugal.
- Institute of Molecular Pathology and Immunology of the University of Porto (Ipatimup)-Cancer Biology, Rua Dr. Roberto Frias, s/n, Porto 4200-465, Portugal.
| | - Jean-Philippe Merlio
- Cutaneous Lymphoma Oncogenesis Team INSERM U1053 Bordeaux Research in Translational Oncology, Bordeaux University, Bordeaux 33076, France.
- Tumor Bank and Tumor Biology Laboratory, University Hospital Center Bordeaux, Pessac 33604, France.
| | - Paula Soares
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto 4200-135, Portugal.
- Institute of Molecular Pathology and Immunology of the University of Porto (Ipatimup)-Cancer Biology, Rua Dr. Roberto Frias, s/n, Porto 4200-465, Portugal.
- Department of Pathology and Oncology, Medical Faculty of Porto University, Porto 4200-319, Portugal.
| | - Edith Chevret
- Cutaneous Lymphoma Oncogenesis Team INSERM U1053 Bordeaux Research in Translational Oncology, Bordeaux University, Bordeaux 33076, France.
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16
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Transcription Regulation of the Human Telomerase Reverse Transcriptase (hTERT) Gene. Genes (Basel) 2016; 7:genes7080050. [PMID: 27548225 PMCID: PMC4999838 DOI: 10.3390/genes7080050] [Citation(s) in RCA: 101] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Revised: 07/23/2016] [Accepted: 08/01/2016] [Indexed: 12/11/2022] Open
Abstract
Embryonic stem cells and induced pluripotent stem cells have the ability to maintain their telomere length via expression of an enzymatic complex called telomerase. Similarly, more than 85%–90% of cancer cells are found to upregulate the expression of telomerase, conferring them with the potential to proliferate indefinitely. Telomerase Reverse Transcriptase (TERT), the catalytic subunit of telomerase holoenzyme, is the rate-limiting factor in reconstituting telomerase activity in vivo. To date, the expression and function of the human Telomerase Reverse Transcriptase (hTERT) gene are known to be regulated at various molecular levels (including genetic, mRNA, protein and subcellular localization) by a number of diverse factors. Among these means of regulation, transcription modulation is the most important, as evident in its tight regulation in cancer cell survival as well as pluripotent stem cell maintenance and differentiation. Here, we discuss how hTERT gene transcription is regulated, mainly focusing on the contribution of trans-acting factors such as transcription factors and epigenetic modifiers, as well as genetic alterations in hTERT proximal promoter.
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17
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hTERT promoter methylation in meningiomas and central nervous hemangiopericytomas. J Neurooncol 2016; 130:79-87. [PMID: 27465278 DOI: 10.1007/s11060-016-2226-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Accepted: 07/22/2016] [Indexed: 01/30/2023]
Abstract
In meningiomas, prognostic impact of mutations in the human telomerase reverse transcriptase (hTERT) promoter region was recently shown, while studies of promoter methylation and analyses of hemangiopericytomas are lacking. hTERT promoter methylation was analyzed in 78 meningioma and 38 meningeal hemangiopericytoma samples by methylation-specific polymerase chain reaction (MS-PCR) and compared with histopathological and clinical variables and with immunohistochemical hTERT expression. Promoter methylation was found in 62 samples (53 %) and tended to be higher in meningiomas (N = 19/41, 46 %) than in hemangiopericytomas (N = 8/33, 24 %, p = .057). In meningiomas, methylation was 16, 60 and 77 % in grade I, II and III tumors (p < .001) and higher in recurrent (N = 33/37, 89 %) than in primary diagnosed (N = 19/41, 46 %) tumors (OR 5.14, 95 % CI 1.34-19.71, p = .017). Univariate analyses showed shorter mean progression free and overall survival in methylated than in unmethylated individuals (26 vs. 100 months; p = .045 and 110 vs. 113 months; p = .025, respectively). Moreover, hTERT expression was found in 70 % (N = 53) and was more frequent in methylated than in unmethylated samples (78 vs. 52 %, OR 3.36, 95 % CI 1.20-9.40, p = .021). In hemangiopericytomas, methylation was similar in grade II (24 %) and III (25 %, p > .05) and in primary (24 %) and recurrent tumors (40 %, p > .05). hTERT expression was similar as compared to meningiomas (74 %, N = 28, p > .05) but was independent of promoter methylation (OR 4.26, 95 % CI 0.47-39.0, p = .199). In meningeal tumors, hTERT promoter methylation is more common than mutations and in meningiomas but not in hemangiopericytomas positively correlated with WHO grade and hTERT expression.
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18
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Zhang X, Li B, de Jonge N, Björkholm M, Xu D. The DNA methylation inhibitor induces telomere dysfunction and apoptosis of leukemia cells that is attenuated by telomerase over-expression. Oncotarget 2016; 6:4888-900. [PMID: 25682873 PMCID: PMC4467122 DOI: 10.18632/oncotarget.2917] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2014] [Accepted: 12/14/2014] [Indexed: 01/27/2023] Open
Abstract
DNA methyltransferase inhibitors (DNMTIs) such as 5-azacytidine (5-AZA) have been used for treatment of acute myeloid leukemia (AML) and other malignancies. Although inhibiting global/gene-specific DNA methylation is widely accepted as a key mechanism behind DNMTI anti-tumor activity, other mechanisms are likely involved in DNMTI's action. Because telomerase reverse transcriptase (TERT) plays key roles in cancer through telomere elongation and telomere lengthening-independent activities, and TERT has been shown to confer chemo- or radio-resistance to cancer cells, we determine whether DNMTIs affect telomere function and whether TERT/telomerase interferes with their anti-cancer efficacy. We showed that 5-AZA induced DNA damage and telomere dysfunction in AML cell lines by demonstrating the presence of 53-BP1 foci and the co-localization of 53-BP1 foci with telomere signals, respectively. Telomere dysfunction was coupled with diminished TERT expression, shorter telomere and apoptosis in 5-AZA-treated cells. However, 5-AZA treatment did not lead to changes in the methylation status of subtelomere regions. Down-regulation of TERT expression similarly occurred in primary leukemic cells derived from AML patients exposed to 5-AZA. TERT over-expression significantly attenuated 5-AZA-mediated DNA damage, telomere dysfunction and apoptosis of AML cells. Collectively, 5-AZA mediates the down-regulation of TERT expression, and induces telomere dysfunction, which consequently exerts an anti-tumor activity.
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Affiliation(s)
- Xiaolu Zhang
- Department of Medicine, Division of Hematology and Center for Molecular Medicine, Karolinska Institutet and Karolinska University Hospital Solna, Stockholm, Sweden
| | - Bingnan Li
- Department of Medicine, Division of Hematology and Center for Molecular Medicine, Karolinska Institutet and Karolinska University Hospital Solna, Stockholm, Sweden
| | - Nick de Jonge
- Department of Medicine, Division of Hematology and Center for Molecular Medicine, Karolinska Institutet and Karolinska University Hospital Solna, Stockholm, Sweden
| | - Magnus Björkholm
- Department of Medicine, Division of Hematology and Center for Molecular Medicine, Karolinska Institutet and Karolinska University Hospital Solna, Stockholm, Sweden
| | - Dawei Xu
- Department of Medicine, Division of Hematology and Center for Molecular Medicine, Karolinska Institutet and Karolinska University Hospital Solna, Stockholm, Sweden
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19
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Zhang H, Weng X, Ye J, He L, Zhou D, Liu Y. Promoter hypermethylation of TERT is associated with hepatocellular carcinoma in the Han Chinese population. Clin Res Hepatol Gastroenterol 2015; 39:600-9. [PMID: 25683523 DOI: 10.1016/j.clinre.2015.01.002] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2014] [Revised: 01/05/2015] [Accepted: 01/12/2015] [Indexed: 02/04/2023]
Abstract
BACKGROUND Upstream of the transcription start site (UTSS), hypermethylation of the telomerase reverse transcriptase (TERT) gene has been shown to be associated with tumour progression and a poor prognosis in paediatric brain tumours (Castelo-Branco 2013). It has been inferred that the UTSS region of TERT is a potentially accessible biomarker for various cancers. In this study, we aimed to explore the role of TERT in hepatocellular carcinoma (HCC) and to investigate whether the UTSS region of the TERT promoter shows the same methylation pattern in HCC. METHODS We analysed the results of a methylation assay for TERT, including the UTSS region, from 125 paired HCC samples using Mass Array EpiTyper (Sequenom, San Diego, CA, USA). To determine the relationship between TERT promoter methylation status and the TERT expression level, we analysed a validation group of 12 paired HCC samples and acquired the FPKM values for the TERT gene. RESULTS Our results showed aberrant methylation of the UTSS region of the TERT promoter in HCC (mean=15.1) compared with the adjacent normal tissues (mean=6.1, P<0.00001). Furthermore, a nearly 56-fold increase in TERT expression from the hypermethylated promoter was found in HCC (P<0.05), indicating a positive relationship between TERT methylation and expression. CONCLUSIONS As hypermethylation was positively correlated with high expression of TERT in HCC, TERT is likely to be involved in the aetiology of HCC. Our findings indicate that future studies on TERT might be fruitful.
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Affiliation(s)
- Hong Zhang
- Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, PR China
| | - Xiaoling Weng
- Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, PR China
| | - Junyi Ye
- Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, PR China
| | - Lin He
- Bio-X Centre Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, Shanghai 200030, PR China
| | - Daizhan Zhou
- Bio-X Centre Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, Shanghai 200030, PR China.
| | - Yun Liu
- Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, PR China.
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20
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Nickerson ML, Dancik GM, Im KM, Edwards MG, Turan S, Brown J, Ruiz-Rodriguez C, Owens C, Costello JC, Guo G, Tsang SX, Li Y, Zhou Q, Cai Z, Moore LE, Lucia MS, Dean M, Theodorescu D. Concurrent alterations in TERT, KDM6A, and the BRCA pathway in bladder cancer. Clin Cancer Res 2015; 20:4935-48. [PMID: 25225064 DOI: 10.1158/1078-0432.ccr-14-0330] [Citation(s) in RCA: 95] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE Genetic analysis of bladder cancer has revealed a number of frequently altered genes, including frequent alterations of the telomerase (TERT) gene promoter, although few altered genes have been functionally evaluated. Our objective is to characterize alterations observed by exome sequencing and sequencing of the TERT promoter, and to examine the functional relevance of histone lysine (K)-specific demethylase 6A (KDM6A/UTX), a frequently mutated histone demethylase, in bladder cancer. EXPERIMENTAL DESIGN We analyzed bladder cancer samples from 54 U.S. patients by exome and targeted sequencing and confirmed somatic variants using normal tissue from the same patient. We examined the biologic function of KDM6A using in vivo and in vitro assays. RESULTS We observed frequent somatic alterations in BRCA1 associated protein-1 (BAP1) in 15% of tumors, including deleterious alterations to the deubiquitinase active site and the nuclear localization signal. BAP1 mutations contribute to a high frequency of tumors with breast cancer (BRCA) DNA repair pathway alterations and were significantly associated with papillary histologic features in tumors. BAP1 and KDM6A mutations significantly co-occurred in tumors. Somatic variants altering the TERT promoter were found in 69% of tumors but were not correlated with alterations in other bladder cancer genes. We examined the function of KDM6A, altered in 24% of tumors, and show depletion in human bladder cancer cells, enhanced in vitro proliferation, in vivo tumor growth, and cell migration. CONCLUSIONS This study is the first to identify frequent BAP1 and BRCA pathway alterations in bladder cancer, show TERT promoter alterations are independent of other bladder cancer gene alterations, and show KDM6A loss is a driver of the bladder cancer phenotype.
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Affiliation(s)
- Michael L Nickerson
- Cancer and Inflammation Program, National Cancer Institute, National Institutes of Health, Frederick, Maryland
| | | | - Kate M Im
- Cancer and Inflammation Program, National Cancer Institute, National Institutes of Health, Frederick, Maryland
| | - Michael G Edwards
- Division of Pulmonary Sciences and Critical Care, Department of Medicine, University of Colorado, Denver, Aurora, Colorado
| | - Sevilay Turan
- Cancer and Inflammation Program, National Cancer Institute, National Institutes of Health, Frederick, Maryland
| | | | - Christina Ruiz-Rodriguez
- Cancer and Inflammation Program, National Cancer Institute, National Institutes of Health, Frederick, Maryland
| | - Charles Owens
- Department of Surgery, University of Colorado, Aurora, Colorado
| | - James C Costello
- Department of Pharmacology, University of Colorado, Aurora, Colorado
| | | | | | | | | | - Zhiming Cai
- Shenzhen Second People's Hospital, Shenzhen, China
| | - Lee E Moore
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Rockville, Maryland
| | - M Scott Lucia
- Department of Pathology, University of Colorado, Aurora, Colorado
| | - Michael Dean
- Cancer and Inflammation Program, National Cancer Institute, National Institutes of Health, Frederick, Maryland
| | - Dan Theodorescu
- Department of Surgery, University of Colorado, Aurora, Colorado. Department of Pharmacology, University of Colorado, Aurora, Colorado. University of Colorado Comprehensive Cancer Center, Aurora, Colorado.
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21
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Rea IM, Dellet M, Mills KI. Living long and ageing well: is epigenomics the missing link between nature and nurture? Biogerontology 2015; 17:33-54. [PMID: 26133292 DOI: 10.1007/s10522-015-9589-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2015] [Accepted: 06/22/2015] [Indexed: 12/12/2022]
Abstract
Human longevity is a complex trait and increasingly we understand that both genes and lifestyle interact in the longevity phenotype. Non-genetic factors, including diet, physical activity, health habits, and psychosocial factors contribute approximately 50% of the variability in human lifespan with another 25% explained by genetic differences. Family clusters of nonagenarian and centenarian siblings, who show both exceptional age-span and health-span, are likely to have inherited facilitatory gene groups, but also have nine decades of life experiences and behaviours which have interacted with their genetic profiles. Identification of their shared genes is just one small step in the link from genes to their physical and psychological profiles. Behavioural genomics is beginning to demonstrate links to biological mechanisms through regulation of gene expression, which directs the proteome and influences the personal phenotype. Epigenetics has been considered the missing link between nature and nurture. Although there is much that remains to be discovered, this article will discuss some of genetic and environmental factors which appear important in good quality longevity and link known epigenetic mechanisms to themes identified by nonagenarians themselves related to their longevity. Here we suggest that exceptional 90-year old siblings have adopted a range of behaviours and life-styles which have contributed to their ageing-well-phenotype and which link with important public health messages.
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Affiliation(s)
- Irene Maeve Rea
- School of Medicine, Dentistry and Biomedical Science, Queens University Belfast, Belfast, Northern Ireland, UK. .,School of Biomedical Sciences, University of Ulster, Coleraine, Northern Ireland, UK.
| | - Margaret Dellet
- School of Medicine, Dentistry and Biomedical Science, Queens University Belfast, Belfast, Northern Ireland, UK.,Centre for Experimental Medicine, School of Medicine, Dentistry and Biomedical Science, Queens University Belfast , Belfast, Northern Ireland, UK
| | - Ken I Mills
- School of Medicine, Dentistry and Biomedical Science, Queens University Belfast, Belfast, Northern Ireland, UK.,Centre for Cancer Research and Cell Biology, School of Medicine, Dentistry and Biomedical Science, Queens University Belfast, Belfast, Northern Ireland, UK
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22
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Zhang ZX, Wang Y, Tao ZZ, Chen SM, Xiao BK, Zhou T. Subtelomeric Demethylation Deregulated hTERT Expression, Telomerase Activity, and Telomere Length in Four Nasopharyngeal Carcinoma Cell Lines. Cancer Biother Radiopharm 2014; 29:289-94. [PMID: 25153197 DOI: 10.1089/cbr.2013.1581] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Affiliation(s)
- Zi-Xiong Zhang
- Department of Otolaryngology, Head and Neck Surgery, Renmin Hospital of Wuhan University , Wuhan, People's Republic of China
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23
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Eldholm V, Haugen A, Zienolddiny S. CTCF mediates the TERT enhancer-promoter interactions in lung cancer cells: identification of a novel enhancer region involved in the regulation of TERT gene. Int J Cancer 2013; 134:2305-13. [PMID: 24174344 DOI: 10.1002/ijc.28570] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2013] [Revised: 08/19/2013] [Accepted: 10/18/2013] [Indexed: 01/18/2023]
Abstract
Telomerase activation is a hallmark of cancer. Although the regulation of the telomerase reverse transcriptase catalytic subunit (TERT), the rate-limiting factor for telomerase activity, has been studied intensively it remains incompletely understood. In cells devoid of telomerase activity, TERT is embedded in a region of condensed chromatin and the chromatin remodeling protein CCCTC-binding factor (CTCF) has been implicated in the inhibition of TERT expression. The importance of TERT activation for cellular immortalization and carcinogenesis is attested by the fact that the gene is expressed in more than 90% of immortal cell lines and tumors and that gain of TERT is the most frequent amplification event in early stage lung cancer. This study was designed to study the mechanisms of regulation of the TERT gene expression by the CTCF transcription factor in three human lung cancer cell lines, A427, A549 and H838. Depletion of CTCF by siRNA resulted in reduced TERT mRNA levels in two (A427 and A549) of the three cell lines. A novel enhancer element was identified approximately 4.5 kb upstream of the TERT transcription start site. Chromatin immunoprecipitation experiments revealed recruitment of CTCF to this enhancer element. Chromosome conformation capture experiments demonstrated the presence of CTCF-dependent chromatin loops between this enhancer element and the TERT proximal promoter in A427 and A549 cell lines. In summary, the results show that CTCF plays an important role in maintaining TERT expression in a subset of human lung cancer cell lines. This role may be due to CTCF-dependent enhancer-promoter interactions.
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Affiliation(s)
- Vegard Eldholm
- Department of Chemical and Biological Work Environment, National Institute of Occupational Health, Oslo, Norway
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24
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Vajen B, Thomay K, Schlegelberger B. Induction of Chromosomal Instability via Telomere Dysfunction and Epigenetic Alterations in Myeloid Neoplasia. Cancers (Basel) 2013; 5:857-74. [PMID: 24202323 PMCID: PMC3795368 DOI: 10.3390/cancers5030857] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2013] [Revised: 06/17/2013] [Accepted: 06/25/2013] [Indexed: 12/19/2022] Open
Abstract
Chromosomal instability (CIN) is a characteristic feature of cancer. In this review, we concentrate on mechanisms leading to CIN in myeloid neoplasia, i.e., myelodysplastic syndrome (MDS) or acute myeloid leukemia (AML). The pathogenesis of myeloid neoplasia is complex and involves genetic and epigenetic alterations. Chromosome aberrations define specific subgroups and guide clinical decisions. Genomic instability may play an essential role in leukemogenesis by promoting the accumulation of genetic lesions responsible for clonal evolution. Indeed, disease progression is often driven by clonal evolution into complex karyotypes. Earlier studies have shown an association between telomere shortening and advanced MDS and underlined the important role of dysfunctional telomeres in the development of genetic instability and cancer. Several studies link chromosome rearrangements and aberrant DNA and histone methylation. Genes implicated in epigenetic control, like DNMT3A, ASXL1, EZH2 and TET2, have been discovered to be mutated in MDS. Moreover, gene-specific hypermethylation correlates highly significantly with the risk score according to the International Prognostic Scoring System. In AML, methylation profiling also revealed clustering dependent on the genetic status. Clearly, genetic instability and clonal evolution are driving forces for leukemic transformation. Understanding the mechanisms inducing CIN will be important for prevention and for novel approaches towards therapeutic interventions.
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Affiliation(s)
- Beate Vajen
- Institute of Cell and Molecular Pathology, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany.
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25
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Zhang XJ, Xu Z, Gong YL, Tang CJ, Chen JF. Association of TERT rs2736098 Polymorphism with Cancer Risk: a Meta-analysis. Asian Pac J Cancer Prev 2012; 13:4943-6. [DOI: 10.7314/apjcp.2012.13.10.4943] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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