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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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Santourlidis S, Araúzo-Bravo MJ, Brodell RT, Hassan M, Bendhack ML. hTERT Epigenetics Provides New Perspectives for Diagnosis and Evidence-Based Guidance of Chemotherapy in Cancer. Int J Mol Sci 2024; 25:7331. [PMID: 39000438 PMCID: PMC11242863 DOI: 10.3390/ijms25137331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2024] [Revised: 06/25/2024] [Accepted: 07/01/2024] [Indexed: 07/16/2024] Open
Abstract
Strong epigenetic pan-cancer biomarkers are required to meet several current, urgent clinical needs and to further improve the present chemotherapeutic standard. We have concentrated on the investigation of epigenetic alteration of the hTERT gene, which is frequently epigenetically dysregulated in a number of cancers in specific developmental stages. Distinct DNA methylation profiles were identified in our data on early urothelial cancer. An efficient EpihTERT assay could be developed utilizing suitable combinations with sequence-dependent thermodynamic parameters to distinguish between differentially methylated states. We infer from this data set, the epigenetic context, and the related literature that a CpG-rich, 2800 bp region, a prominent CpG island, surrounding the transcription start of the hTERT gene is the crucial epigenetic zone for the development of a potent biomarker. In order to accurately describe this region, we have named it "Acheron" (Ἀχέρων). In Greek mythology, this is the river of woe and misery and the path to the underworld. Exploitation of the DNA methylation profiles focused on this region, e.g., idiolocal normalized Methylation Specific PCR (IDLN-MSP), opens up a wide range of new possibilities for diagnosis, determination of prognosis, follow-up, and detection of residual disease. It may also have broad implications for the choice of chemotherapy.
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Affiliation(s)
- Simeon Santourlidis
- Institute of Transplantation Diagnostics and Cell Therapeutics, Medical Faculty, Heinrich Heine University Duesseldorf, Moorenstr. 5, 40225 Duesseldorf, Germany
| | - Marcos J. Araúzo-Bravo
- Group of Computational Biology and Systems Biomedicine, Biodonostia Health Research Institute, 20014 San Sebastián, Spain;
- Ikerbasque, Basque Foundation for Science, 48013 Bilbao, Spain
- Department of Cell Biology and Histology, Faculty of Medicine and Nursing, University of Basque Country (UPV/EHU), 48940 Leioa, Spain
| | - Robert T. Brodell
- Department of Pathology, University of Mississippi Medical Center, Jackson, MS 39216, USA;
| | - Mohamed Hassan
- Institut National de la Santé et de la Recherche Médicale, 67000 Strasbourg, France;
- Department of Surgery, Tulane University School of Medicine, New Orleans, LA 70112, USA
| | - Marcelo L. Bendhack
- Department of Urology, Red Cross University Hospital, Positivo University, Rua Mauá 1111, Curitiba 80030-200, Brazil;
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Sang Y, Hu G, Xue J, Chen M, Hong S, Liu R. Risk stratification by combining common genetic mutations and TERT promoter methylation in papillary thyroid cancer. Endocrine 2024; 85:304-312. [PMID: 38356100 DOI: 10.1007/s12020-024-03722-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2023] [Accepted: 01/30/2024] [Indexed: 02/16/2024]
Abstract
PURPOSE Risk stratification based on somatic mutations in TERT promoter and BRAF/RAS has been well established for papillary thyroid cancer (PTC), and there is emerging evidence showed that TERT promoter methylation was frequently observed in thyroid cancer patients with adverse features. This study was aimed to comprehensive explore the prognostic value of BRAF/RAS mutations, TERT promoter mutations, and TERT promoter methylation in PTC. METHODS The relationships of BRAF/RAS mutations, TERT promoter mutations, and TERT promoter methylation with clinical characteristics and outcomes of PTC were analyzed in 382 patients with PTC. RESULTS TERT promoter mutation and hypermethylation were collectively observed in 52 (13.6%) samples and associated with BRAF/RAS mutation, aggressive clinical characteristics, and poor clinical outcomes of PTC. Coexistence of BRAF/RAS and TERT alterations was found in 45 of 382 (11.8%) PTC patients and strongly associated with old patient age, extrathyroidal extension, advanced pathologic T stage and metastasis. Importantly, patients with both BRAF/RAS and TERT alterations had higher rates of tumor recurrence (13.6% vs 1.5%, P = 0.042) and disease progression (24.4% vs 3.3%, P < 0.001) than patients without any alterations, and cox regression analysis revealed that the coexistence of BRAF/RAS and TERT alterations, but not BRAF/RAS or TERT alterations alone, increased the risk of progression-free interval with an adjusted HR of 10.35 (95% CI: 1.79-59.81, P = 0.009). CONCLUSIONS This study suggested that comprehensively analysis of BRAF/RAS mutations, TERT promoter mutation and methylation is an effective strategy to identify high-risk patients with PTC.
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Affiliation(s)
- Ye Sang
- Institute of Precision Medicine, The First Affiliated Hospital, Sun Yat-Sen University, No. 58, Zhongshan Second Road, Guangzhou, China
| | - Guanghui Hu
- Institute of Precision Medicine, The First Affiliated Hospital, Sun Yat-Sen University, No. 58, Zhongshan Second Road, Guangzhou, China
| | - Junyu Xue
- Department of Endocrinology, The First Affiliated Hospital, Sun Yat-Sen University, No. 58, Zhongshan Second Road, Guangzhou, China
| | - Mengke Chen
- Institute of Precision Medicine, The First Affiliated Hospital, Sun Yat-Sen University, No. 58, Zhongshan Second Road, Guangzhou, China
| | - Shubin Hong
- Department of Endocrinology, The First Affiliated Hospital, Sun Yat-Sen University, No. 58, Zhongshan Second Road, Guangzhou, China
| | - Rengyun Liu
- Institute of Precision Medicine, The First Affiliated Hospital, Sun Yat-Sen University, No. 58, Zhongshan Second Road, Guangzhou, China.
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Koukourikis P, Papaioannou M, Pervana S, Apostolidis A. Exploring the DNA Methylation Profile of Genes Associated with Bladder Cancer in Bladder Tissue of Patients with Neurogenic Lower Urinary Tract Dysfunction. Int J Mol Sci 2024; 25:5660. [PMID: 38891848 PMCID: PMC11171624 DOI: 10.3390/ijms25115660] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2024] [Revised: 05/12/2024] [Accepted: 05/19/2024] [Indexed: 06/21/2024] Open
Abstract
DNA methylation is an epigenetic process that commonly occurs in genes' promoters and results in the transcriptional silencing of genes. DNA methylation is a frequent event in bladder cancer, participating in tumor initiation and progression. Bladder cancer is a major health issue in patients suffering from neurogenic lower urinary tract dysfunction (NLUTD), although the pathogenetic mechanisms of the disease remain unclear. In this population, bladder cancer is characterized by aggressive histopathology, advanced stage during diagnosis, and high mortality rates. To assess the DNA methylation profiles of five genes' promoters previously known to be associated with bladder cancer in bladder tissue of NLUTD patients, we conducted a prospective study recruiting NLUTD patients from the neuro-urology unit of a public teaching hospital. Cystoscopy combined with biopsy for bladder cancer screening was performed in all patients following written informed consent being obtained. Quantitative methylation-specific PCR was used to determine the methylation status of RASSF1, RARβ, DAPK, hTERT, and APC genes' promoters in bladder tissue samples. Twenty-four patients suffering from mixed NLUTD etiology for a median duration of 10 (IQR: 12) years were recruited in this study. DNA hypermethylation was detected in at least one gene of the panel in all tissue samples. RAR-β was hypermethylated in 91.7% samples, RASSF and DAPK were hypermethylated in 83.3% samples, APC 37.5% samples, and TERT in none of the tissue samples. In 45.8% of the samples, three genes of the panel were hypermethylated, in 29.2% four genes were hypermethylated, and in 16.7% and in 8.3% of the samples, two and one gene were hypermethylated, respectively. The number of hypermethylated genes of the panel was significantly associated with recurrent UTIs (p = 0.0048). No other significant association was found between DNA hypermethylation or the number of hypermethylated genes and the clinical characteristics of the patients. Histopathological findings were normal in 8.3% of patients, while chronic inflammation was found in 83.3% of patients and squamous cell metaplasia in 16.7% of patients. In this study, we observed high rates of DNA hypermethylation of genes associated with bladder cancer in NLUTD patients, suggesting an epigenetic field effect and possible risk of bladder cancer development. Recurrent UTIs seem to be associated with increased DNA hypermethylation. Further research is needed to evaluate the impact of recurrent UTIs and chronic inflammation in DNA hypermethylation and bladder cancer etiopathogenesis in NLUTD patients.
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Affiliation(s)
- Periklis Koukourikis
- 2nd Department of Urology, Aristotle University of Thessaloniki, General Hospital ‘Papageorgiou’, 56403 Thessaloniki, Greece;
| | - Maria Papaioannou
- Department of Biological Chemistry, Medical School, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece;
| | - Stavroula Pervana
- Department of Pathology, General Hospital ‘Papageorgiou’, 56403 Thessaloniki, Greece;
| | - Apostolos Apostolidis
- 2nd Department of Urology, Aristotle University of Thessaloniki, General Hospital ‘Papageorgiou’, 56403 Thessaloniki, Greece;
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Li S, Xue J, Jiang K, Chen Y, Zhu L, Liu R. TERT promoter methylation is associated with high expression of TERT and poor prognosis in papillary thyroid cancer. Front Oncol 2024; 14:1325345. [PMID: 38313800 PMCID: PMC10834694 DOI: 10.3389/fonc.2024.1325345] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2023] [Accepted: 01/04/2024] [Indexed: 02/06/2024] Open
Abstract
The telomerase reverse transcriptase (TERT) is overexpressed and associated with poor prognosis in papillary thyroid cancer (PTC), the most common subtype of thyroid cancer. The overexpression of TERT in PTC was partially attributed to transcriptional activation by two hotspot mutations in the core promoter region of this gene. As one of the major epigenetic mechanisms of gene expression regulation, DNA methylation has been proved to regulate several tumor-related genes in PTC. However, the association of TERT promoter DNA methylation with TERT expression and PTC progression is still unclear. By treating PTC cell lines with demethylating agent decitabine, we found that the TERT promoter methylation and the genes' expression were remarkably decreased. Consistently, PTC patients with TERT hypermethylation had significantly higher TERT expression than patients with TERT hypomethylation. Moreover, TERT hypermethylated patients showed significant higher rates of poor clinical outcomes than patients with TERT hypomethylation. Results from the cox regression analysis showed that the hazard ratios (HRs) of TERT hypermethylation for overall survival, disease-specific survival, disease-free interval (DFI) and progression-free interval (PFI) were 4.81 (95% CI, 1.61-14.41), 8.28 (95% CI, 2.14-32.13), 3.56 (95% CI, 1.24-10.17) and 3.32 (95% CI, 1.64-6.71), respectively. The HRs for DFI and PFI remained significant after adjustment for clinical risk factors. These data suggest that promoter DNA methylation upregulates TERT expression and associates with poor clinical outcomes of PTC, thus holds the potential to be a valuable prognostic marker for PTC risk stratification.
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Affiliation(s)
- Shiyong Li
- Institute of Precision Medicine, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Junyu Xue
- Department of Endocrinology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Ke Jiang
- Department of Head and Neck Surgery, Sun Yat-sen University Cancer Center, Guangzhou, China
| | - Yulu Chen
- Institute of Precision Medicine, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Lefan Zhu
- Institute of Precision Medicine, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Rengyun Liu
- Institute of Precision Medicine, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
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Kouroukli AG, Rajaram N, Bashtrykov P, Kretzmer H, Siebert R, Jeltsch A, Bens S. Targeting oncogenic TERT promoter variants by allele-specific epigenome editing. Clin Epigenetics 2023; 15:183. [PMID: 37993930 PMCID: PMC10666398 DOI: 10.1186/s13148-023-01599-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Accepted: 11/10/2023] [Indexed: 11/24/2023] Open
Abstract
BACKGROUND Activation of dominant oncogenes by small or structural genomic alterations is a common driver mechanism in many cancers. Silencing of such dominantly activated oncogenic alleles, thus, is a promising strategy to treat cancer. Recently, allele-specific epigenome editing (ASEE) has been described as a means to reduce transcription of genes in an allele-specific manner. In cancer, specificity to an oncogenic allele can be reached by either targeting directly a pathogenic single-nucleotide variant or a polymorphic single-nucleotide variant linked to the oncogenic allele. To investigate the potential of ASEE in cancer, we here explored this approach by targeting variants at the TERT promoter region. The TERT promoter region has been described as one of the most frequently mutated non-coding cancer drivers. RESULTS Sequencing of the TERT promoter in cancer cell lines showed 53% (41/77) to contain at least one heterozygous sequence variant allowing allele distinction. We chose the hepatoblastoma cell line Hep-G2 and the lung cancer cell line A-549 for this proof-of-principle study, as they contained two different kinds of variants, namely the activating mutation C228T in the TERT core promoter and the common SNP rs2853669 in the THOR region, respectively. These variants were targeted in an allele-specific manner using sgRNA-guided dCas9-DNMT3A-3L complexes. In both cell lines, we successfully introduced DNA methylation specifically to the on-target allele of the TERT promoter with limited background methylation on the off-target allele or an off-target locus (VEGFA), respectively. We observed a maximum CpG methylation gain of 39% and 76% on the target allele when targeting the activating mutation and the common SNP, respectively. The epigenome editing translated into reduced TERT RNA expression in Hep-G2. CONCLUSIONS We applied an ASEE-mediated approach to silence TERT allele specifically. Our results show that the concept of dominant oncogene inactivation by allele-specific epigenome editing can be successfully translated into cancer models. This new strategy may have important advantages in comparison with existing therapeutic approaches, e.g., targeting telomerase, especially with regard to reducing adverse side effects.
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Affiliation(s)
- Alexandra G Kouroukli
- Institute of Human Genetics, Ulm University and Ulm University Medical Center, Albert-Einstein-Allee 11, 89081, Ulm, Germany
| | - Nivethika Rajaram
- Department of Biochemistry, Institute of Biochemistry and Technical Biochemistry, University of Stuttgart, Allmandring 31, 70569, Stuttgart, Germany
| | - Pavel Bashtrykov
- Department of Biochemistry, Institute of Biochemistry and Technical Biochemistry, University of Stuttgart, Allmandring 31, 70569, Stuttgart, Germany
| | - Helene Kretzmer
- Computational Genomics, Department of Genome Regulation, Max Planck Institute for Molecular Genetics, Berlin, Germany
| | - Reiner Siebert
- Institute of Human Genetics, Ulm University and Ulm University Medical Center, Albert-Einstein-Allee 11, 89081, Ulm, Germany
| | - Albert Jeltsch
- Department of Biochemistry, Institute of Biochemistry and Technical Biochemistry, University of Stuttgart, Allmandring 31, 70569, Stuttgart, Germany
| | - Susanne Bens
- Institute of Human Genetics, Ulm University and Ulm University Medical Center, Albert-Einstein-Allee 11, 89081, Ulm, Germany.
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Fagin JA, Krishnamoorthy GP, Landa I. Pathogenesis of cancers derived from thyroid follicular cells. Nat Rev Cancer 2023; 23:631-650. [PMID: 37438605 PMCID: PMC10763075 DOI: 10.1038/s41568-023-00598-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 06/08/2023] [Indexed: 07/14/2023]
Abstract
The genomic simplicity of differentiated cancers derived from thyroid follicular cells offers unique insights into how oncogenic drivers impact tumour phenotype. Essentially, the main oncoproteins in thyroid cancer activate nodes in the receptor tyrosine kinase-RAS-BRAF pathway, which constitutively induces MAPK signalling to varying degrees consistent with their specific biochemical mechanisms of action. The magnitude of the flux through the MAPK signalling pathway determines key elements of thyroid cancer biology, including differentiation state, invasive properties and the cellular composition of the tumour microenvironment. Progression of disease results from genomic lesions that drive immortalization, disrupt chromatin accessibility and cause cell cycle checkpoint dysfunction, in conjunction with a tumour microenvironment characterized by progressive immunosuppression. This Review charts the genomic trajectories of these common endocrine tumours, while connecting them to the biological states that they confer.
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Affiliation(s)
- James A Fagin
- Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
| | - Gnana P Krishnamoorthy
- Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Iñigo Landa
- Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
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8
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Yang R, Han Y, Guan X, Hong Y, Meng J, Ding S, Long Q, Yi W. Regulation and clinical potential of telomerase reverse transcriptase (TERT/hTERT) in breast cancer. Cell Commun Signal 2023; 21:218. [PMID: 37612721 PMCID: PMC10463831 DOI: 10.1186/s12964-023-01244-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Accepted: 07/23/2023] [Indexed: 08/25/2023] Open
Abstract
Telomerase reverse transcriptase (TERT/hTERT) serves as the pivotal catalytic subunit of telomerase, a crucial enzyme responsible for telomere maintenance and human genome stability. The high activation of hTERT, observed in over 90% of tumors, plays a significant role in tumor initiation and progression. An in-depth exploration of hTERT activation mechanisms in cancer holds promise for advancing our understanding of the disease and developing more effective treatment strategies. In breast cancer, the expression of hTERT is regulated by epigenetic, transcriptional, post-translational modification mechanisms and DNA variation. Besides its canonical function in telomere maintenance, hTERT exerts non-canonical roles that contribute to disease progression through telomerase-independent mechanisms. This comprehensive review summarizes the regulatory mechanisms governing hTERT in breast cancer and elucidates the functional implications of its activation. Given the overexpression of hTERT in most breast cancer cells, the detection of hTERT and its associated molecules are potential for enhancing early screening and prognostic evaluation of breast cancer. Although still in its early stages, therapeutic approaches targeting hTERT and its regulatory molecules show promise as viable strategies for breast cancer treatment. These methods are also discussed in this paper. Video Abstract.
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Affiliation(s)
- Ruozhu Yang
- Department of General Surgery, the Second Xiangya Hospital of Central South University, 139 Middle Renmin Road, Changsha, 410011, China
| | - Yi Han
- Department of General Surgery, the Second Xiangya Hospital of Central South University, 139 Middle Renmin Road, Changsha, 410011, China
| | - Xinyu Guan
- Department of General Surgery, the Second Xiangya Hospital of Central South University, 139 Middle Renmin Road, Changsha, 410011, China
| | - Yue Hong
- Department of General Surgery, the Second Xiangya Hospital of Central South University, 139 Middle Renmin Road, Changsha, 410011, China
| | - Jiahao Meng
- Department of General Surgery, the Second Xiangya Hospital of Central South University, 139 Middle Renmin Road, Changsha, 410011, China
| | - Shirong Ding
- Department of Oncology, the Second Xiangya Hospital of Central South University, 139 Middle Renmin Road, Changsha, 410011, China.
| | - Qian Long
- Department of General Surgery, the Second Xiangya Hospital of Central South University, 139 Middle Renmin Road, Changsha, 410011, China.
| | - Wenjun Yi
- Department of General Surgery, the Second Xiangya Hospital of Central South University, 139 Middle Renmin Road, Changsha, 410011, China.
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Kouroukli AG, Fischer A, Kretzmer H, Chteinberg E, Rajaram N, Glaser S, Kolarova J, Bashtrykov P, Mathas S, Drexler HG, Ohno H, Ammerpohl O, Jeltsch A, Siebert R, Bens S. The DNA methylation status of the TERT promoter differs between subtypes of mature B-cell lymphomas. Blood Cancer J 2023; 13:98. [PMID: 37365157 DOI: 10.1038/s41408-023-00872-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Revised: 05/24/2023] [Accepted: 06/14/2023] [Indexed: 06/28/2023] Open
Affiliation(s)
- Alexandra G Kouroukli
- Institute of Human Genetics, Ulm University and Ulm University Medical Center, 89091, Ulm, Germany
| | - Anja Fischer
- Institute of Human Genetics, Ulm University and Ulm University Medical Center, 89091, Ulm, Germany
| | - Helene Kretzmer
- Computational Genomics, Department of Genome Regulation, Max Planck Institute for Molecular Genetics, Berlin, Germany
| | - Emil Chteinberg
- Institute of Human Genetics, Ulm University and Ulm University Medical Center, 89091, Ulm, Germany
| | - Nivethika Rajaram
- Institute of Biochemistry and Technical Biochemistry, Department of Biochemistry, Stuttgart University, Allmandring 31, 70569, Stuttgart, Germany
| | - Selina Glaser
- Institute of Human Genetics, Ulm University and Ulm University Medical Center, 89091, Ulm, Germany
| | - Julia Kolarova
- Institute of Human Genetics, Ulm University and Ulm University Medical Center, 89091, Ulm, Germany
| | - Pavel Bashtrykov
- Institute of Biochemistry and Technical Biochemistry, Department of Biochemistry, Stuttgart University, Allmandring 31, 70569, Stuttgart, Germany
| | - Stephan Mathas
- Charité - Universitätsmedizin Berlin, Hematology, Oncology and Tumor Immunology, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
- Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association (MDC), Group Biology of Malignant Lymphomas, Berlin, Germany
- Experimental and Clinical Research Center (ECRC), a cooperation between the MDC and the Charité, Berlin, Germany
| | - Hans G Drexler
- Department of Human and Animal Cell Lines, Leibniz-Institute DSMZ-German Collection of Microorganisms and Cell Cultures, Inhoffenstr. 7B, D-38124, Braunschweig, Germany
| | - Hitoshi Ohno
- Tenri Institute of Medical Research, Tenri Hospital, Tenri, Nara, Japan
| | - Ole Ammerpohl
- Institute of Human Genetics, Ulm University and Ulm University Medical Center, 89091, Ulm, Germany
| | - Albert Jeltsch
- Institute of Biochemistry and Technical Biochemistry, Department of Biochemistry, Stuttgart University, Allmandring 31, 70569, Stuttgart, Germany
| | - Reiner Siebert
- Institute of Human Genetics, Ulm University and Ulm University Medical Center, 89091, Ulm, Germany
| | - Susanne Bens
- Institute of Human Genetics, Ulm University and Ulm University Medical Center, 89091, Ulm, Germany.
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10
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Liu T, Li S, Xia C, Xu D. TERT promoter mutations and methylation for telomerase activation in urothelial carcinomas: New mechanistic insights and clinical significance. Front Immunol 2023; 13:1071390. [PMID: 36713366 PMCID: PMC9877314 DOI: 10.3389/fimmu.2022.1071390] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2022] [Accepted: 12/28/2022] [Indexed: 01/15/2023] Open
Abstract
Telomerase, an RNA-dependent DNA polymerase synthesizing telomeric TTAGGG sequences, is primarily silent in normal human urothelial cells (NHUCs), but widely activated in urothelial cell-derived carcinomas or urothelial carcinomas (UCs) including UC of the bladder (UCB) and upper track UC (UTUC). Telomerase activation for telomere maintenance is required for the UC development and progression, and the key underlying mechanism is the transcriptional de-repression of the telomerase reverse transcriptase (TERT), a gene encoding the rate-limiting, telomerase catalytic component. Recent mechanistic explorations have revealed important roles for TERT promoter mutations and aberrant methylation in activation of TERT transcription and telomerase in UCs. Moreover, these TERT-featured genomic and epigenetic alterations have been evaluated for their usefulness in non-invasive UC diagnostics, recurrence monitoring, outcome prediction and response to treatments such as immunotherapy. Importantly, the detection of the mutated TERT promoter and TERT mRNA as urinary biomarkers holds great promise for urine-based UC liquid biopsy. In the present article, we review recent mechanistic insights into altered TERT promoter-mediated telomerase activation in UCs and discuss potential clinical implications. Specifically, we compare differences in senescence and transformation between NHUCs and other types of epithelial cells, address the interaction between TERT promoter mutations and other factors to affect UC progression and outcomes, evaluate the impact of TERT promoter mutations and TERT-mediated activation of human endogenous retrovirus genes on UC immunotherapy including Bacillus Calmette-Guérin therapy and immune checkpoint inhibitors. Finally, we suggest the standardization of a TERT assay and evaluation system for UC clinical practice.
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Affiliation(s)
- Tiantian Liu
- Department of Pathology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Shihong Li
- Department of Pathology, Maternal and Child Health Hospital of Liaocheng, Liaocheng, China
| | - Chuanyou Xia
- Department of Urology, The First Affiliated Hospital of Shandong First Medical University & Shandong Provincial Qianfoshan Hospital, Jinan, China,*Correspondence: Chuanyou Xia, ; Dawei Xu,
| | - Dawei Xu
- Department of Medicine, Bioclinicum and Center for Molecular Medicine (CMM), Karolinska Institutet and Karolinska University Hospital Solna, Stockholm, Sweden,*Correspondence: Chuanyou Xia, ; Dawei Xu,
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11
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Yuan X, Yuan H, Zhang N, Liu T, Xu D. Thyroid carcinoma-featured telomerase activation and telomere maintenance: Biology and translational/clinical significance. Clin Transl Med 2022; 12:e1111. [PMID: 36394204 PMCID: PMC9670192 DOI: 10.1002/ctm2.1111] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Revised: 10/26/2022] [Accepted: 10/30/2022] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Telomerase is a ribonucleoprotein complex consisting of a catalytic component telomerase reverse transcriptase (TERT), internal RNA template and other co-factors, and its essential function is to synthesize telomeric DNA, repetitive TTAGGG sequences at the termini of linear chromosomes. Telomerase is silent in normal human follicular thyroid cells, primarily due to the TERT gene being tightly repressed. During the development and progression of thyroid carcinomas (TCs), TERT induction and telomerase activation is in general required to maintain telomere length, thereby conferring TC cells with immortal and aggressive phenotypes. METHODS The genomic alterations of the TERT loci including TERT promoter's gain-of-function mutations, copy number gain, fusion and rearrangements, have recently been identified in TCs as mechanisms to induce TERT expression and to activate telomerase. Importantly, numerous studies have consistently shown that TERT promoter mutations and TERT expression occur in all TC subtypes, and are robustly associated with TC malignancy, aggressiveness, treatment failure and poor outcomes. Therefore, the assessment of TERT promoter mutations and TERT expression is highly valuable in TC diagnostics, prognosis, treatment decision, and follow-up design. In addition, the TERT promoter is frequently hypermethylated in TC cells and tumors, which is required to activate TERT transcription and telomerase. Dysregulation of other components in the telomerase complex similarly upregulate telomerase. Moreover, shortened telomeres lead to altered gene expression and metabolism, thereby actively promoting TC aggressiveness. Here we summarize recent findings in TCs to provide the landscape of TC-featured telomere/telomerase biology and discuss underlying implications in TC precision medicine. CONCLUSION Mechanistic insights into telomerase activation and TERT induction in TCs are important both biologically and clinically. The TERT gene aberration and expression-based molecular classification of TCs is proposed, and for such a purpose, the standardization of the assay and evaluation system is required. Moreover, the TERT-based system and 2022 WHO TC classification may be combined to improve TC care.
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Affiliation(s)
- Xiaotian Yuan
- Laboratory Animal CenterShandong Provincial Hospital Affiliated to Shandong First Medical UniversityJinanChina
| | - Huiyang Yuan
- Department of UrologyQilu HospitalCheeloo College of MedicineShandong UniversityJinanChina
| | - Ning Zhang
- Department of Breast SurgeryGeneral Surgery, Qilu Hospital of Shandong UniversityJinanChina
| | - Tiantian Liu
- Department of PathologySchool of Basic Medical SciencesCheeloo College of MedicineShandong UniversityJinanChina
| | - Dawei Xu
- Department of MedicineDivision of HematologyBioclinicum and Center for Molecular Medicine (CMM)Karolinska Institutet and Karolinska University Hospital SolnaStockholmSweden
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12
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Karami Fath M, Azargoonjahromi A, Soofi A, Almasi F, Hosseinzadeh S, Khalili S, Sheikhi K, Ferdousmakan S, Owrangi S, Fahimi M, Zalpoor H, Nabi Afjadi M, Payandeh Z, Pourzardosht N. Current understanding of epigenetics role in melanoma treatment and resistance. Cancer Cell Int 2022; 22:313. [PMID: 36224606 PMCID: PMC9555085 DOI: 10.1186/s12935-022-02738-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Accepted: 09/19/2022] [Indexed: 11/30/2022] Open
Abstract
Melanoma is the most aggressive form of skin cancer resulting from genetic mutations in melanocytes. Several factors have been considered to be involved in melanoma progression, including genetic alteration, processes of damaged DNA repair, and changes in mechanisms of cell growth and proliferation. Epigenetics is the other factor with a crucial role in melanoma development. Epigenetic changes have become novel targets for treating patients suffering from melanoma. These changes can alter the expression of microRNAs and their interaction with target genes, which involves cell growth, differentiation, or even death. Given these circumstances, we conducted the present review to discuss the melanoma risk factors and represent the current knowledge about the factors related to its etiopathogenesis. Moreover, various epigenetic pathways, which are involved in melanoma progression, treatment, and chemo-resistance, as well as employed epigenetic factors as a solution to the problems, will be discussed in detail.
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Affiliation(s)
- Mohsen Karami Fath
- Department of Cellular and Molecular Biology, Faculty of Biological Sciences, Kharazmi University, Tehran, Iran
| | | | - Asma Soofi
- Department of Physical Chemistry, School of Chemistry, College of Sciences, University of Tehran, Tehran, Iran
| | - Faezeh Almasi
- Pharmaceutical Biotechnology Lab, Department of Microbial Biotechnology, School of Biology and Center of Excellence in Phylogeny of Living Organisms, College of Science, University of Tehran, Tehran, Iran
| | - Shahnaz Hosseinzadeh
- Department of Microbiology, Parasitology and Immunology, Ardabil University of Medical Sciences, Ardabil, Iran
| | - Saeed Khalili
- Department of Biology Sciences, Shahid Rajaee Teacher Training University, Tehran, Iran
| | - Kamran Sheikhi
- School of Medicine, Kurdistan University of Medical Sciences, Kurdistan, Iran
| | - Saeid Ferdousmakan
- Department of Pharmacy Practice, Nargund College of Pharmacy, Bangalore, 560085 India
| | - Soroor Owrangi
- Student Research Committe, Fasa University of Medical Sciences, Fasa, Iran
| | | | - Hamidreza Zalpoor
- Shiraz Neuroscience Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
- Network of Immunity in Infection, Malignancy & Autoimmunity (NIIMA), Universal Scientific Education & Research Network (USERN), Tehran, Iran
| | - Mohsen Nabi Afjadi
- Department of Biochemistry, Faculty of Biological Science, Tarbiat Modares University, Tehran, Iran
| | - Zahra Payandeh
- Department Medical Biochemistry and Biophysics, Division Medical Inflammation Research, Karolinska Institute, Stockholm, Sweden
| | - Navid Pourzardosht
- Biochemistry Department, Guilan University of Medical Sciences, Rasht, Iran
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13
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Targeted Long-Read Bisulfite Sequencing Identifies Differences in the TERT Promoter Methylation Profiles between TERT Wild-Type and TERT Mutant Cancer Cells. Cancers (Basel) 2022; 14:cancers14164018. [PMID: 36011010 PMCID: PMC9406525 DOI: 10.3390/cancers14164018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2022] [Revised: 08/06/2022] [Accepted: 08/10/2022] [Indexed: 11/17/2022] Open
Abstract
Background: TERT promoter methylation, located several hundred base pairs upstream of the transcriptional start site, is cancer specific and correlates with increased TERT mRNA expression and poorer patient outcome. Promoter methylation, however, is not mutually exclusive to TERT activating genetic alterations, as predicted for functionally redundant mechanisms. To annotate the altered patterns of TERT promoter methylation and their relationship with gene expression, we applied a Pacific Biosciences-based, long-read, bisulfite-sequencing technology and compared the differences in the methylation marks between wild-type and mutant cancers in an allele-specific manner. Results: We cataloged TERT genetic alterations (i.e., promoter point mutations or structural variations), allele-specific promoter methylation patterns, and allele-specific expression levels in a cohort of 54 cancer cell lines. In heterozygous mutant cell lines, the mutant alleles were significantly less methylated than their silent, mutation-free alleles (p < 0.05). In wild-type cell lines, by contrast, both epialleles were equally methylated to high levels at the TERT distal promoter, but differentially methylated in the proximal regions. ChIP analysis showed that epialleles with the hypomethylated proximal and core promoter were enriched in the active histone mark H3K4me2/3, whereas epialleles that were methylated in those regions were enriched in the repressive histone mark H3K27me3. Decitabine therapy induced biallelic expression in the wild-type cancer cells, whereas the mutant cell lines were unaffected. Conclusions: Long-read bisulfite sequencing analysis revealed differences in the methylation profiles and responses to demethylating agents between TERT wild-type and genetically altered cancer cell lines. The causal relation between TERT promoter methylation and gene expression remains to be established.
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14
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Xiang Y, Chen Q, Li Q, Liang C, Cao W. The expression level of chicken telomerase reverse transcriptase in tumors induced by ALV-J is positively correlated with methylation and mutation of its promoter region. Vet Res 2022; 53:49. [PMID: 35739589 PMCID: PMC9229480 DOI: 10.1186/s13567-022-01069-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2022] [Accepted: 05/30/2022] [Indexed: 11/10/2022] Open
Abstract
Avian leukosis virus subgroup J (ALV-J) can cause neoplastic diseases in poultry and is still widely prevalent in China. Chicken telomerase reverse transcriptase (chTERT) is the core component of telomerase, which is closely related to the occurrence and development of tumors. Our previous studies showed that chTERT is overexpressed in ALV-J tumors, but the mechanism is still not completely clear. Therefore, this study aims to analyze the possible molecular mechanism of chTERT overexpression in ALV-J tumors from the perspective of DNA methylation and promoter mutation. Methylation sequencing of the chTERT amplicon showed that ALV-J replication promoted the methylation level of the chTERT promoter. And the methylation level of the chTERT promoter in ALV-J tumors was significantly higher than that in tumor-adjacent and normal tissues. Compared with the tumor-adjacent and normal tissues, the chTERT promoter in each ALV-J tumors tested had a mutation of -183 bp C > T, and 36.0% (9/25) of the tumors also had mutations of -184 bp T > C, -73 bp::GGCCC and -56 bp A > T in the chTERT promoter, which formed the binding sites for the transcription factors NFAT5, TFAP2A and ZEB1, respectively. The results of RT-qPCR and Western blotting showed that the occurrence of these mutations significantly increased the expression level of chTERT. In conclusion, this study demonstrated that the high expression of chTERT in ALV-J tumors is positively correlated with the level of hypermethylation and mutation in its promoter, which provides a new perspective for further research on the molecular mechanism of chTERT in ALV-J tumorigenesis.
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Affiliation(s)
- Yong Xiang
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510642, China
| | - Qinxi Chen
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510642, China
| | - Qingbo Li
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510642, China
| | - Canxin Liang
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510642, China
| | - Weisheng Cao
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510642, China. .,Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, South China Agricultural University, Guangzhou, 510642, China. .,National and Regional Joint Engineering Laboratory for Medicament of Zoonosis Prevention and Control, South China Agricultural University, Guangzhou, 510642, China. .,Key Laboratory of Zoonosis of the Ministry of Agriculture and Rural Affairs, Guangzhou, 510642, China. .,Key Laboratory of Veterinary Vaccine Innovation of the Ministry of Agriculture and Rural Affairs, Guangzhou, 510642, China.
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15
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Emerging mechanisms of telomerase reactivation in cancer. Trends Cancer 2022; 8:632-641. [PMID: 35568649 PMCID: PMC7614490 DOI: 10.1016/j.trecan.2022.03.005] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 03/24/2022] [Accepted: 03/28/2022] [Indexed: 12/17/2022]
Abstract
Mutations in the promoter of human telomerase reverse transcriptase (hTERT) result in hyperactivation of hTERT. Notably, all mutations are G>A transitions, frequently found in a wide range of cancer types, and causally associated with cancer progression. Initially, the mutations were understood to reactivate hTERT by generating novel E26 transformation-specific (ETS) binding sites. Recent work reveals the role of DNA secondary structure G-quadruplexes, telomere binding factor(s), and chromatin looping in hTERT regulation. Here, we discuss these emerging findings in relation to the clinically significant promoter mutations to provide a broader understanding of the context-dependent outcomes that result in hTERT activation in normal and pathogenic conditions.
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16
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Xiang Y, Liang C, Li Q, Chen Q, Zhou Y, Zheng X, Zhou D, Wang Z, Wang G, Cao W. Chicken telomerase reverse transcriptase promotes the tumorigenicity of avian leukosis virus subgroup J by regulating the Wnt/β-catenin signaling pathway. Vet Res 2022; 53:100. [PMID: 36461084 PMCID: PMC9717515 DOI: 10.1186/s13567-022-01120-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Accepted: 10/24/2022] [Indexed: 12/03/2022] Open
Abstract
This research aimed to analyze the regulatory effect of chicken telomerase reverse transcriptase (chTERT) on the Wnt/β-catenin signaling pathway and its effect on the tumorigenicity of avian leukosis virus subgroup J (ALV-J) through in vivo experiments. The chTERT eukaryotic expression plasmid and its recombinant lentivirus particles were constructed for in vivo transfection of chTERT to analyze the effect of chTERT continuously overexpressed in chickens on the tumorigenicity of ALV-J. During 156 days of the artificial ALV-J tumor-inducing process, 7 solid tumors developed in 3 chickens in the chTERT-overexpression group (n = 26*2) and no tumors developed in the control group (n = 26*2). Another 18 tumors induced by ALV-J were confirmed and collected from breeding poultry farms. And we confirmed that chTERT was significantly highly expressed in ALV-J tumors. The ELISA data suggested that the protein levels of β-catenin and c-Myc in the chicken plasma of the chTERT-overexpressing group with ALV-J infected were consistently and significantly higher than those of the control group. Compared with that of the tumor-adjacent tissues, the activity of the Wnt/β-catenin signaling pathway and expression of the c-Myc was significantly increased in ALV-J tumors. And the percentage of apoptosis in ALV-J tumors significantly lower than that in tumor-adjacent tissues. Immunohistochemistry, Western blot and RT-qPCR suggested that the replication level of ALV-J in tumors was significantly higher than that in tumor-adjacent tissues. This study suggests that chTERT plays a critical role in the tumorigenicity of ALV-J by enhancing the Wnt/β-catenin signaling pathway, which will contribute to further elucidating the tumor-inducing mechanism of ALV-J.
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Affiliation(s)
- Yong Xiang
- grid.20561.300000 0000 9546 5767College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510642 China
| | - Canxin Liang
- grid.20561.300000 0000 9546 5767College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510642 China
| | - Qingbo Li
- grid.20561.300000 0000 9546 5767College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510642 China
| | - Qinxi Chen
- grid.20561.300000 0000 9546 5767College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510642 China
| | - Yang Zhou
- grid.20561.300000 0000 9546 5767College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510642 China
| | - Xiaoxue Zheng
- grid.20561.300000 0000 9546 5767College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510642 China
| | - Di Zhou
- grid.20561.300000 0000 9546 5767College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510642 China
| | - Zepeng Wang
- grid.20561.300000 0000 9546 5767College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510642 China
| | - Guyao Wang
- grid.20561.300000 0000 9546 5767College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510642 China
| | - Weisheng Cao
- grid.20561.300000 0000 9546 5767College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510642 China ,grid.20561.300000 0000 9546 5767Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, South China Agricultural University, Guangzhou, 510642 China ,grid.20561.300000 0000 9546 5767National and Regional Joint Engineering Laboratory for Medicament of Zoonosis Prevention and Control, South China Agricultural University, Guangzhou, 510642 China ,grid.20561.300000 0000 9546 5767Key Laboratory of Zoonosis of the Ministry of Agriculture and Rural Affairs, South China Agricultural University, Guangzhou, 510642 China ,grid.20561.300000 0000 9546 5767Key Laboratory of Veterinary Vaccine Innovation of the Ministry of Agriculture and Rural Affairs, South China Agricultural University, Guangzhou, 510642 China
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17
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TERT Promoter Mutations Increase Sense and Antisense Transcription from the TERT Promoter. Biomedicines 2021; 9:biomedicines9121773. [PMID: 34944589 PMCID: PMC8698883 DOI: 10.3390/biomedicines9121773] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 11/19/2021] [Accepted: 11/22/2021] [Indexed: 12/21/2022] Open
Abstract
Background: Chief among mechanisms of telomerase reverse transcriptase (TERT) reactivation is the appearance of mutations in the TERT promoter. The two main TERT promoter mutations are C>T transitions located −146C>T and −124C>T upstream from the translational start site. They generate a novel Ets/TCF binding site. Both mutations are mutually exclusive and −124C>T is strikingly overrepresented in most cancers. We investigated whether this mutational bias and mutual exclusion could be due to transcriptional constraints. Methods: We compared sense and antisense transcription of a panel of TERT promoter-luciferase vectors harboring the −124C>T and -146C>T mutations alone or together. lncRNA TAPAS levels were measured by RT-PCR. Results: Both mutations generally increased TERT transcription by 2–4-fold regardless of upstream and downstream regulatory elements. The double mutant increased transcription in an additive fashion, arguing against a direct transcriptional constraint. The −146C>T mutation, alone or in combination with −124C>T, also unleashed antisense transcription. In line with this finding, lncRNA TAPAS was higher in cells with mutated TERT promoter (T98G and U87) than in cells with wild-type promoter, suggesting that lncRNA TAPAS may balance the effect of TERT promoter mutations. Conclusions: −146C>T and −124C>T TERT promoter mutations increase TERT sense and antisense transcription, and the double mutant features higher transcription levels. Increased antisense transcription may contain TERT expression within sustainable levels.
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18
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Lee DD, Komosa M, Sudhaman S, Leão R, Zhang CH, Apolonio JD, Hermanns T, Wild PJ, Klocker H, Nassiri F, Zadeh G, Diplas BH, Yan H, Gallinger S, Pugh TJ, Ramaswamy V, Taylor MD, Castelo-Branco P, Nunes NM, Tabori U. Dual role of allele-specific DNA hypermethylation within the TERT promoter in cancer. J Clin Invest 2021; 131:146915. [PMID: 34720085 DOI: 10.1172/jci146915] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 09/16/2021] [Indexed: 11/17/2022] Open
Abstract
Aberrant activation of telomerase in human cancer is achieved by various alterations within the TERT promoter, including cancer-specific DNA hypermethylation of the TERT hypermethylated oncological region (THOR). However, the impact of allele-specific DNA methylation within the TERT promoter on gene transcription remains incompletely understood. Using allele-specific next-generation sequencing, we screened a large cohort of normal and tumor tissues (n = 652) from 10 cancer types and identified that differential allelic methylation (DAM) of THOR is restricted to cancerous tissue and commonly observed in major cancer types. THOR-DAM was more common in adult cancers, which develop through multiple stages over time, than in childhood brain tumors. Furthermore, THOR-DAM was especially enriched in tumors harboring the activating TERT promoter mutations (TPMs). Functional studies revealed that allele-specific gene expression of TERT requires hypomethylation of the core promoter, both in TPM and TERT WT cancers. However, the expressing allele with hypomethylated core TERT promoter universally exhibits hypermethylation of THOR, while the nonexpressing alleles are either hypermethylated or hypomethylated throughout the promoter. Together, our findings suggest a dual role for allele-specific DNA methylation within the TERT promoter in the regulation of TERT expression in cancer.
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Affiliation(s)
- Donghyun D Lee
- Program in Genetics and Genome Biology and.,The Arthur and Sonia Labatt Brain Tumour Research Centre, The Hospital for Sick Children, Toronto, Ontario, Canada.,Institute of Medical Science, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Martin Komosa
- Program in Genetics and Genome Biology and.,The Arthur and Sonia Labatt Brain Tumour Research Centre, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Sumedha Sudhaman
- Program in Genetics and Genome Biology and.,The Arthur and Sonia Labatt Brain Tumour Research Centre, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Ricardo Leão
- The Arthur and Sonia Labatt Brain Tumour Research Centre, The Hospital for Sick Children, Toronto, Ontario, Canada.,Faculty of Medicine, University of Coimbra, Coimbra, Portugal
| | - Cindy H Zhang
- Program in Genetics and Genome Biology and.,The Arthur and Sonia Labatt Brain Tumour Research Centre, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Joana D Apolonio
- Program in Genetics and Genome Biology and.,The Arthur and Sonia Labatt Brain Tumour Research Centre, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Thomas Hermanns
- Department of Urology, University Hospital Zürich, University of Zurich, Zurich, Switzerland
| | - Peter J Wild
- Dr. Senckenberg Institute of Pathology, University Hospital Frankfurt, Germany.,Frankfurt Institute for Advanced Studies (FIAS), Frankfurt, Germany
| | - Helmut Klocker
- Department of Urology, Medical University of Innsbruck, Innsbruck, Austria
| | - Farshad Nassiri
- Division of Neurosurgery, University of Toronto, Toronto Western Hospital, University Health Network, Toronto, Ontario, Canada
| | - Gelareh Zadeh
- Division of Neurosurgery, University of Toronto, Toronto Western Hospital, University Health Network, Toronto, Ontario, Canada
| | - Bill H Diplas
- Department of Pathology, Duke University Medical Center, Durham, North Carolina, USA
| | - Hai Yan
- Department of Pathology, Duke University Medical Center, Durham, North Carolina, USA
| | - Steven Gallinger
- Lunenfeld Tanenbaum Research Institute, Mount Sinai Hospital, University of Toronto, Toronto, Ontario, Canada
| | - Trevor J Pugh
- Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada
| | - Vijay Ramaswamy
- The Arthur and Sonia Labatt Brain Tumour Research Centre, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Michael D Taylor
- The Arthur and Sonia Labatt Brain Tumour Research Centre, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Pedro Castelo-Branco
- Faculdade de Medicina e Ciências Biomédicas (FMCB), Universidade do Algarve, Faro, Portugal.,Algarve Biomedical Center Research Institute, Faro, Portugal.,Centre for Biomedical Research, University of Algarve, Faro, Portugal.,Champalimaud Research Program, Champalimaud Centre for the Unknown, Lisbon, Portugal
| | - Nuno Miguel Nunes
- Program in Genetics and Genome Biology and.,The Arthur and Sonia Labatt Brain Tumour Research Centre, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Uri Tabori
- Program in Genetics and Genome Biology and.,The Arthur and Sonia Labatt Brain Tumour Research Centre, The Hospital for Sick Children, Toronto, Ontario, Canada
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19
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Epigenetic features in regulation of telomeres and telomerase in stem cells. Emerg Top Life Sci 2021; 5:497-505. [PMID: 34486664 DOI: 10.1042/etls20200344] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 07/28/2021] [Accepted: 08/10/2021] [Indexed: 01/12/2023]
Abstract
The epigenetic nature of telomeres is still controversial and different human cell lines might show diverse histone marks at telomeres. Epigenetic modifications regulate telomere length and telomerase activity that influence telomere structure and maintenance. Telomerase is responsible for telomere elongation and maintenance and is minimally composed of the catalytic protein component, telomerase reverse transcriptase (TERT) and template forming RNA component, telomerase RNA (TERC). TERT promoter mutations may underpin some telomerase activation but regulation of the gene is not completely understood due to the complex interplay of epigenetic, transcriptional, and posttranscriptional modifications. Pluripotent stem cells (PSCs) can maintain an indefinite, immortal, proliferation potential through their endogenous telomerase activity, maintenance of telomere length, and a bypass of replicative senescence in vitro. Differentiation of PSCs results in silencing of the TERT gene and an overall reversion to a mortal, somatic cell phenotype. The precise mechanisms for this controlled transcriptional silencing are complex. Promoter methylation has been suggested to be associated with epigenetic control of telomerase regulation which presents an important prospect for understanding cancer and stem cell biology. Control of down-regulation of telomerase during differentiation of PSCs provides a convenient model for the study of its endogenous regulation. Telomerase reactivation has the potential to reverse tissue degeneration, drive repair, and form a component of future tissue engineering strategies. Taken together it becomes clear that PSCs provide a unique system to understand telomerase regulation fully and drive this knowledge forward into aging and therapeutic application.
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20
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Hu K, Ghandi M, Huang FW. Integrated evaluation of telomerase activation and telomere maintenance across cancer cell lines. eLife 2021; 10:e66198. [PMID: 34486523 PMCID: PMC8530513 DOI: 10.7554/elife.66198] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2021] [Accepted: 08/27/2021] [Indexed: 12/12/2022] Open
Abstract
In cancer, telomere maintenance is critical for the development of replicative immortality. Using genome sequences from the Cancer Cell Line Encyclopedia and Genomics of Drug Sensitivity in Cancer Project, we calculated telomere content across 1299 cancer cell lines. We find that telomerase reverse transcriptase (TERT) expression correlates with telomere content in lung, central nervous system, and leukemia cell lines. Using CRISPR/Cas9 screening data, we show that lower telomeric content is associated with dependency of CST telomere maintenance genes. Increased dependencies of shelterin members are associated with wild-type TP53 status. Investigating the epigenetic regulation of TERT, we find widespread allele-specific expression in promoter-wildtype contexts. TERT promoter-mutant cell lines exhibit hypomethylation at PRC2-repressed regions, suggesting a cooperative global epigenetic state in the reactivation of telomerase. By incorporating telomere content with genomic features across comprehensively characterized cell lines, we provide further insights into the role of telomere regulation in cancer immortality.
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Affiliation(s)
- Kevin Hu
- Broad Institute of MIT and HarvardCambridgeUnited States
- Division of Hematology/Oncology, Department of Medicine; Bakar Computational Health Sciences Institute; Institute for Human Genetics; University of California, San FranciscoSan FranciscoUnited States
- Helen Diller Family Comprehensive Cancer CenterSan FranciscoUnited States
| | - Mahmoud Ghandi
- Broad Institute of MIT and HarvardCambridgeUnited States
| | - Franklin W Huang
- Broad Institute of MIT and HarvardCambridgeUnited States
- Division of Hematology/Oncology, Department of Medicine; Bakar Computational Health Sciences Institute; Institute for Human Genetics; University of California, San FranciscoSan FranciscoUnited States
- Helen Diller Family Comprehensive Cancer CenterSan FranciscoUnited States
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21
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Rachakonda S, Hoheisel JD, Kumar R. Occurrence, functionality and abundance of the TERT promoter mutations. Int J Cancer 2021; 149:1852-1862. [PMID: 34313327 DOI: 10.1002/ijc.33750] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 06/14/2021] [Accepted: 07/16/2021] [Indexed: 12/18/2022]
Abstract
Telomere shortening at chromosomal ends due to the constraints of the DNA replication process acts as a tumor suppressor by restricting the replicative potential in primary cells. Cancers evade that limitation primarily through the reactivation of telomerase via different mechanisms. Mutations within the promoter of the telomerase reverse transcriptase (TERT) gene represent a definite mechanism for the ribonucleic enzyme regeneration predominantly in cancers that arise from tissues with low rates of self-renewal. The promoter mutations cause a moderate increase in TERT transcription and consequent telomerase upregulation to the levels sufficient to delay replicative senescence but not prevent bulk telomere shortening and genomic instability. Since the discovery, a staggering number of studies have resolved the discrete aspects, effects and clinical relevance of the TERT promoter mutations. The promoter mutations link transcription of TERT with oncogenic pathways, associate with markers of poor outcome and define patients with reduced survivals in several cancers. In this review, we discuss the occurrence and impact of the promoter mutations and highlight the mechanism of TERT activation. We further deliberate on the foundational question of the abundance of the TERT promoter mutations and a general dearth of functional mutations within noncoding sequences, as evident from pan-cancer analysis of the whole-genomes. We posit that the favorable genomic constellation within the TERT promoter may be less than a common occurrence in other noncoding functional elements. Besides, the evolutionary constraints limit the functional fraction within the human genome, hence the lack of abundant mutations outside the coding sequences.
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Affiliation(s)
| | - Jörg D Hoheisel
- Division of Functional Genome Analysis, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Rajiv Kumar
- Division of Functional Genome Analysis, German Cancer Research Center (DKFZ), Heidelberg, Germany.,Department of Molecular Biology of Cancer, Institute of Experimental Medicine of the Czech Academy of Sciences, Prague, Czech Republic
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22
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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: 4.0] [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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23
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McKelvey BA, Zeiger MA, Umbricht CB. Exploring the epigenetic regulation of telomerase reverse transcriptase (TERT) in human cancer cell lines. Mol Oncol 2020; 14:2355-2357. [PMID: 32920953 PMCID: PMC7530778 DOI: 10.1002/1878-0261.12798] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Accepted: 09/04/2020] [Indexed: 11/10/2022] Open
Abstract
Telomerase regulation, including TERT promoter methylation, has been of long-standing interest to cancer biologists. Rowland et al. have now vastly expanded their ongoing characterization of TERT promoter methylation in cancer cells, analyzing the methylation patterns of 833 cell lines from 23 human cancers. They document a highly conserved pattern of hypomethylation around the proximal promoter, as well as a more heterogeneous region of hypermethylation further upstream, both associated with active TERT expression in cancer cells. They further describe the interplay between activating TERT promoter mutations and allelic methylation and transcription patterns. This valuable dataset represents the most extensive characterization of TERT promoter methylation in cancer cells to date and will help guide the future study of transcriptional regulation of telomerase. Comment on: https://doi.org/10.1002/1878-0261.12786.
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Affiliation(s)
- Brittany A. McKelvey
- Department of SurgeryJohns Hopkins UniversityBaltimoreMDUSA
- Department of Molecular Biology and GeneticsJohns Hopkins UniversityBaltimoreMDUSA
| | - Martha A. Zeiger
- Surgical Oncology ProgramNational Cancer InstituteNational Institutes of HealthBethesdaMDUSA
| | - Christopher B. Umbricht
- Department of SurgeryJohns Hopkins UniversityBaltimoreMDUSA
- Department of OncologyJohns Hopkins UniversityBaltimoreMDUSA
- Department of PathologyJohns Hopkins UniversityBaltimoreMDUSA
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