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Yap TA, Tolcher AW, Plummer R, Mukker JK, Enderlin M, Hicking C, Grombacher T, Locatelli G, Szucs Z, Gounaris I, de Bono JS. First-in-Human Study of the Ataxia Telangiectasia and Rad3-Related (ATR) Inhibitor Tuvusertib (M1774) as Monotherapy in Patients with Solid Tumors. Clin Cancer Res 2024; 30:2057-2067. [PMID: 38407317 PMCID: PMC11094421 DOI: 10.1158/1078-0432.ccr-23-2409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Revised: 10/26/2023] [Accepted: 02/21/2024] [Indexed: 02/27/2024]
Abstract
PURPOSE Tuvusertib (M1774) is a potent, selective, orally administered ataxia telangiectasia and Rad3-related (ATR) protein kinase inhibitor. This first-in-human study (NCT04170153) evaluated safety, tolerability, maximum tolerated dose (MTD), recommended dose for expansion (RDE), pharmacokinetics (PK), pharmacodynamics (PD), and preliminary efficacy of tuvusertib monotherapy. PATIENTS AND METHODS Ascending tuvusertib doses were evaluated in 55 patients with metastatic or locally advanced unresectable solid tumors. A safety monitoring committee determined dose escalation based on PK, PD, and safety data guided by a Bayesian 2-parameter logistic regression model. Molecular responses (MR) were assessed in circulating tumor DNA samples. RESULTS Most common grade ≥3 treatment-emergent adverse events were anemia (36%), neutropenia, and lymphopenia (both 7%). Eleven patients experienced dose-limiting toxicities, most commonly grade 2 (n = 2) or 3 (n = 8) anemia. No persistent effects on blood immune cell populations were observed. The RDE was 180 mg tuvusertib QD (once daily), 2 weeks on/1 week off treatment, which was better tolerated than the MTD (180 mg QD continuously). Tuvusertib median time to peak plasma concentration ranged from 0.5 to 3.5 hours and mean elimination half-life from 1.2 to 5.6 hours. Exposure-related PD analysis suggested maximum target engagement at ≥130 mg tuvusertib QD. Tuvusertib induced frequent MRs in the predicted efficacious dose range; MRs were enriched in patients with radiological disease stabilization, and complete MRs were detected for mutations in ARID1A, ATRX, and DAXX. One patient with platinum- and PARP inhibitor-resistant BRCA wild-type ovarian cancer achieved an unconfirmed RECIST v1.1 partial response. CONCLUSIONS Tuvusertib demonstrated manageable safety and exposure-related target engagement. Further clinical evaluation of tuvusertib is ongoing.
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Affiliation(s)
- Timothy A. Yap
- University of Texas MD Anderson Cancer Center, Houston, Texas
| | | | - Ruth Plummer
- Newcastle University and Northern Centre for Cancer Care, Newcastle Hospitals NHS Trust, Newcastle Upon Tyne, United Kingdom
| | | | - Marta Enderlin
- The Healthcare Business of Merck KGaA, Darmstadt, Germany
| | | | | | | | - Zoltan Szucs
- Merck Serono Ltd., Feltham, UK, an affiliate of Merck KGaA, Darmstadt, Germany
| | - Ioannis Gounaris
- Merck Serono Ltd., Feltham, UK, an affiliate of Merck KGaA, Darmstadt, Germany
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Ali JH, Walter M. Combining old and new concepts in targeting telomerase for cancer therapy: transient, immediate, complete and combinatory attack (TICCA). Cancer Cell Int 2023; 23:197. [PMID: 37679807 PMCID: PMC10483736 DOI: 10.1186/s12935-023-03041-2] [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: 02/21/2023] [Accepted: 08/25/2023] [Indexed: 09/09/2023] Open
Abstract
Telomerase can overcome replicative senescence by elongation of telomeres but is also a specific element in most cancer cells. It is expressed more vastly than any other tumor marker. Telomerase as a tumor target inducing replicative immortality can be overcome by only one other mechanism: alternative lengthening of telomeres (ALT). This limits the probability to develop resistance to treatments. Moreover, telomerase inhibition offers some degree of specificity with a low risk of toxicity in normal cells. Nevertheless, only one telomerase antagonist reached late preclinical studies. The underlying causes, the pitfalls of telomerase-based therapies, and future chances based on recent technical advancements are summarized in this review. Based on new findings and approaches, we propose a concept how long-term survival in telomerase-based cancer therapies can be significantly improved: the TICCA (Transient Immediate Complete and Combinatory Attack) strategy.
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Affiliation(s)
- Jaber Haj Ali
- Institute of Laboratory Medicine, Clinical Chemistry and Pathobiochemistry, Charité Universitätsmedizin Berlin, Augustenburger Platz 1, 13353, Berlin, Germany
- Institute of Clinical Chemistry and Laboratory Medicine, Universitätsmedizin Rostock, Ernst-Heydemann-Straße 6, 18057, Rostock, Germany
| | - Michael Walter
- Institute of Clinical Chemistry and Laboratory Medicine, Universitätsmedizin Rostock, Ernst-Heydemann-Straße 6, 18057, Rostock, Germany.
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3
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Sohn EJ, Goralsky JA, Shay JW, Min J. The Molecular Mechanisms and Therapeutic Prospects of Alternative Lengthening of Telomeres (ALT). Cancers (Basel) 2023; 15:cancers15071945. [PMID: 37046606 PMCID: PMC10093677 DOI: 10.3390/cancers15071945] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 03/14/2023] [Accepted: 03/15/2023] [Indexed: 04/14/2023] Open
Abstract
As detailed by the end replication problem, the linear ends of a cell's chromosomes, known as telomeres, shorten with each successive round of replication until a cell enters into a state of growth arrest referred to as senescence. To maintain their immortal proliferation capacity, cancer cells must employ a telomere maintenance mechanism, such as telomerase activation or the Alternative Lengthening of Telomeres pathway (ALT). With only 10-15% of cancers utilizing the ALT mechanism, progress towards understanding its molecular components and associated hallmarks has only recently been made. This review analyzes the advances towards understanding the ALT pathway by: (1) detailing the mechanisms associated with engaging the ALT pathway as well as (2) identifying potential therapeutic targets of ALT that may lead to novel cancer therapeutic treatments. Collectively, these studies indicate that the ALT molecular mechanisms involve at least two distinct pathways induced by replication stress and damage at telomeres. We suggest exploiting tumor dependency on ALT is a promising field of study because it suggests new approaches to ALT-specific therapies for cancers with poorer prognosis. While substantial progress has been made in the ALT research field, additional progress will be required to realize these advances into clinical practices to treat ALT cancers and improve patient prognoses.
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Affiliation(s)
- Eric J Sohn
- Institute for Cancer Genetics, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Julia A Goralsky
- Institute for Cancer Genetics, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Jerry W Shay
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9039, USA
| | - Jaewon Min
- Institute for Cancer Genetics, Columbia University Irving Medical Center, New York, NY 10032, USA
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, NY 10032, USA
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4
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Sun H, Chen G, Guo B, Lv S, Yuan G. Potential clinical treatment prospects behind the molecular mechanism of alternative lengthening of telomeres (ALT). J Cancer 2023; 14:417-433. [PMID: 36860927 PMCID: PMC9969575 DOI: 10.7150/jca.80097] [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: 10/22/2022] [Accepted: 12/25/2022] [Indexed: 02/04/2023] Open
Abstract
Normal somatic cells inevitably experience replicative stress and senescence during proliferation. Somatic cell carcinogenesis can be prevented in part by limiting the reproduction of damaged or old cells and removing them from the cell cycle [1, 2]. However, Cancer cells must overcome the issues of replication pressure and senescence as well as preserve telomere length in order to achieve immortality, in contrast to normal somatic cells [1, 2]. Although telomerase accounts for the bulk of telomere lengthening methods in human cancer cells, there is a non-negligible portion of telomere lengthening pathways that depend on alternative lengthening of telomeres (ALT) [3]. For the selection of novel possible therapeutic targets for ALT-related disorders, a thorough understanding of the molecular biology of these diseases is crucial [4]. The roles of ALT, typical ALT tumor cell traits, the pathophysiology and molecular mechanisms of ALT tumor disorders, such as adrenocortical carcinoma (ACC), are all summarized in this work. Additionally, this research compiles as many of its hypothetically viable but unproven treatment targets as it can (ALT-associated PML bodies (APB), etc.). This review is intended to contribute as much as possible to the development of research, while also trying to provide a partial information for prospective investigations on ALT pathways and associated diseases.
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Affiliation(s)
- Haolu Sun
- Department of Pathophysiology, School of Basic Medical Sciences, Anhui Medical University, Hefei, 230011, China
| | - Guijuan Chen
- School of Environment and Chemical Engineering, Anhui Vocational and Technical College, Hefei, 230011, China
| | - Baochang Guo
- Rehabilitation Department of Traditional Chinese Medicine, 969 Hospital of the Joint Support Force of the Chinese People's Liberation Army, Hohhot, 010000, China
| | - Shushu Lv
- Department of Pathology, The First Affiliated Hospital of Huzhou University, Huzhou 313000, China
| | - Guojun Yuan
- School of Environment and Chemical Engineering, Anhui Vocational and Technical College, Hefei, 230011, China
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5
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de Lima MF, Freitas MO, Hamedani MK, Rangel-Pozzo A, Zhu XD, Mai S. Consecutive Inhibition of Telomerase and Alternative Lengthening Pathway Promotes Hodgkin's Lymphoma Cell Death. Biomedicines 2022; 10:2299. [PMID: 36140400 PMCID: PMC9496562 DOI: 10.3390/biomedicines10092299] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 08/19/2022] [Accepted: 09/12/2022] [Indexed: 11/16/2022] Open
Abstract
Telomere maintenance is key during cancer development. Malignant cells can either use telomerase or an alternative lengthening of telomere (ALT) pathway to maintain their telomere length. In Hodgkin's Lymphoma (HL), the presence of telomerase activation is established. The activation of ALT has been reported recently. Our data confirm this notion describing co-localization of the phosphorylated form of telomeric repeat-binding factor 1 (pT371-TRF1) with ALT-associated promyelocytic leukemia bodies. Surprisingly, to our knowledge, there are no published studies targeting both telomere maintenance pathways in HL. Consequently, we investigated, for the first time, the effects of both telomerase and ALT inhibition on HL cell viability: We inhibited telomerase and/or ALT, given either individually, simultaneously, or consecutively. We report that the inhibition of telomerase using BIBR1532 followed by ALT inhibition, using trabectedin, caused a decrease of greater than 90% in cell viability in three patient-derived HL cell lines. Our results suggest that HL cells are most vulnerable to the consecutive inhibition of telomerase followed by ALT inhibition.
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Affiliation(s)
- Matheus Fabiao de Lima
- Department of Physiology and Pathophysiology, CancerCare Manitoba Research Institute, University of Manitoba, Winnipeg, MB R3E 0V9, Canada
| | - Monique Oliveira Freitas
- Genetic Service, Institute of Paediatrics and Puericulture Martagão Gesteira (IPPMG), Federal University of Rio de Janeiro (UFRJ), Rio de Janeiro 21941-912, Brazil
| | - Mohammad K. Hamedani
- Department of Physiology and Pathophysiology, CancerCare Manitoba Research Institute, University of Manitoba, Winnipeg, MB R3E 0V9, Canada
| | - Aline Rangel-Pozzo
- Department of Physiology and Pathophysiology, CancerCare Manitoba Research Institute, University of Manitoba, Winnipeg, MB R3E 0V9, Canada
| | - Xu-Dong Zhu
- Department of Biology, Faculty of Science, McMaster University, Hamilton, ON L8S 4K1, Canada
| | - Sabine Mai
- Department of Physiology and Pathophysiology, CancerCare Manitoba Research Institute, University of Manitoba, Winnipeg, MB R3E 0V9, Canada
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Insights into Epigenetic Changes Related to Genetic Variants and Cells-of-Origin of Pancreatic Neuroendocrine Tumors: An Algorithm for Practical Workup. Cancers (Basel) 2022; 14:cancers14184444. [PMID: 36139607 PMCID: PMC9496769 DOI: 10.3390/cancers14184444] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 09/04/2022] [Accepted: 09/05/2022] [Indexed: 11/16/2022] Open
Abstract
Simple Summary Pancreatic neuroendocrine tumors are composite entities due to their heterogeneity illustrated in clinical behavior, mutational pattern, and site of origin. Pancreatic neuroendocrine tumors display a low mutation burden with frequently epigenetic alterations, such as histone modifications, chromatin remodeling, or DNA methylation status. Using the epigenomic data of the pancreatic neuroendocrine tumors converged to the identification of molecularly distinct subgroups. Furthermore, epigenetic signatures could be used as biomarkers due to their link to cell lineages and genetic driver mutations. We integrated the current knowledge on genetic and epigenetic alterations involved in endocrine lineage associated with these neoplasms to present a pathway-based overview. In this review, we suggest a simplified algorithm on how to manage pancreatic neuroendocrine tumors from a practical perspective based on pathologist ’analysis. Abstract Current knowledge on the molecular landscape of pancreatic neuroendocrine tumors (PanNETs) has advanced significantly. Still, the cellular origin of PanNETs is uncertain and the associated mechanisms remain largely unknown. DAXX/ATRX and MEN1 are the three most frequently altered genes that drive PanNETs. They are recognized as a link between genetics and epigenetics. Moreover, the acknowledged impact on DNA methylation by somatic mutations in MEN1 is a valid hallmark of epigenetic mechanism. DAXX/ATRX and MEN1 can be studied at the immunohistochemical level as a reliable surrogate for sequencing. DAXX/ATRX mutations promote alternative lengthening of telomeres (ALT) activation, determined by specific fluorescence in situ hybridization (FISH) analysis. ALT phenotype is considered a significant predictor of worse prognosis and a marker of pancreatic origin. Additionally, ARX/PDX1 expression is linked to important epigenomic alterations and can be used as lineage associated immunohistochemical marker. Herein, ARX/PDX1 association with DAXX/ATRX/MEN1 and ALT can be studied through pathological assessment, as these biomarkers may provide important clues to the mechanism underlying disease pathogenesis. In this review, we present an overview of a new approach to tumor stratification based on genetic and epigenetic characteristics as well as cellular origin, with prognostic consequences.
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7
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Hou K, Yu Y, Li D, Zhang Y, Zhang K, Tong J, Yang K, Jia S. Alternative Lengthening of Telomeres and Mediated Telomere Synthesis. Cancers (Basel) 2022; 14:cancers14092194. [PMID: 35565323 PMCID: PMC9105334 DOI: 10.3390/cancers14092194] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 04/24/2022] [Accepted: 04/25/2022] [Indexed: 12/01/2022] Open
Abstract
Simple Summary Alternative lengthing of telomere (ALT) is an important mechanism for maintaining telomere length and cell proliferation in telomerase-negative tumor cells. However, the molecular mechanism of ALT is still poorly understood. ALT occurs in a wide range of tumor types and usually associated with a worse clinical consequence. Here, we review the recent findings of ALT mechanisms, which promise ALT could be a valuable drug target for clinical telomerase-negative tumor treatment. Abstract Telomeres are DNA–protein complexes that protect eukaryotic chromosome ends from being erroneously repaired by the DNA damage repair system, and the length of telomeres indicates the replicative potential of the cell. Telomeres shorten during each division of the cell, resulting in telomeric damage and replicative senescence. Tumor cells tend to ensure cell proliferation potential and genomic stability by activating telomere maintenance mechanisms (TMMs) for telomere lengthening. The alternative lengthening of telomeres (ALT) pathway is the most frequently activated TMM in tumors of mesenchymal and neuroepithelial origin, and ALT also frequently occurs during experimental cellular immortalization of mesenchymal cells. ALT is a process that relies on homologous recombination (HR) to elongate telomeres. However, some processes in the ALT mechanism remain poorly understood. Here, we review the most recent understanding of ALT mechanisms and processes, which may help us to better understand how the ALT pathway is activated in cancer cells and determine the potential therapeutic targets in ALT pathway-stabilized tumors.
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Affiliation(s)
- Kailong Hou
- Faculty of Life Science and Technology, Kunming University of Science and Technology, 727 Jing Ming Nan Road, Kunming 650500, China;
- Laboratory of Molecular Genetics of Aging and Tumor, Medical School, Kunming University of Science and Technology, 727 Jing Ming Nan Road, Kunming 650500, China; (Y.Y.); (D.L.); (Y.Z.); (K.Z.); (J.T.)
- First People’s Hospital of Yunnan Province, 157 Jinbi Road, Kunming 650032, China
| | - Yuyang Yu
- Laboratory of Molecular Genetics of Aging and Tumor, Medical School, Kunming University of Science and Technology, 727 Jing Ming Nan Road, Kunming 650500, China; (Y.Y.); (D.L.); (Y.Z.); (K.Z.); (J.T.)
| | - Duda Li
- Laboratory of Molecular Genetics of Aging and Tumor, Medical School, Kunming University of Science and Technology, 727 Jing Ming Nan Road, Kunming 650500, China; (Y.Y.); (D.L.); (Y.Z.); (K.Z.); (J.T.)
| | - Yanduo Zhang
- Laboratory of Molecular Genetics of Aging and Tumor, Medical School, Kunming University of Science and Technology, 727 Jing Ming Nan Road, Kunming 650500, China; (Y.Y.); (D.L.); (Y.Z.); (K.Z.); (J.T.)
| | - Ke Zhang
- Laboratory of Molecular Genetics of Aging and Tumor, Medical School, Kunming University of Science and Technology, 727 Jing Ming Nan Road, Kunming 650500, China; (Y.Y.); (D.L.); (Y.Z.); (K.Z.); (J.T.)
| | - Jinkai Tong
- Laboratory of Molecular Genetics of Aging and Tumor, Medical School, Kunming University of Science and Technology, 727 Jing Ming Nan Road, Kunming 650500, China; (Y.Y.); (D.L.); (Y.Z.); (K.Z.); (J.T.)
| | - Kunxian Yang
- First People’s Hospital of Yunnan Province, 157 Jinbi Road, Kunming 650032, China
- Correspondence: (K.Y.); (S.J.)
| | - Shuting Jia
- Laboratory of Molecular Genetics of Aging and Tumor, Medical School, Kunming University of Science and Technology, 727 Jing Ming Nan Road, Kunming 650500, China; (Y.Y.); (D.L.); (Y.Z.); (K.Z.); (J.T.)
- Correspondence: (K.Y.); (S.J.)
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8
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Vertecchi E, Rizzo A, Salvati E. Telomere Targeting Approaches in Cancer: Beyond Length Maintenance. Int J Mol Sci 2022; 23:ijms23073784. [PMID: 35409143 PMCID: PMC8998427 DOI: 10.3390/ijms23073784] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 03/25/2022] [Accepted: 03/26/2022] [Indexed: 12/19/2022] Open
Abstract
Telomeres are crucial structures that preserve genome stability. Their progressive erosion over numerous DNA duplications determines the senescence of cells and organisms. As telomere length homeostasis is critical for cancer development, nowadays, telomere maintenance mechanisms are established targets in cancer treatment. Besides telomere elongation, telomere dysfunction impinges on intracellular signaling pathways, in particular DNA damage signaling and repair, affecting cancer cell survival and proliferation. This review summarizes and discusses recent findings in anticancer drug development targeting different “telosome” components.
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Affiliation(s)
- Eleonora Vertecchi
- Institute of Molecular Biology and Pathology, National Research Council, Rome, Italy, c/o Department of Biology and Biotechnology, Sapienza University of Rome, Via degli Apuli 4, 00185 Rome, Italy;
| | - Angela Rizzo
- Oncogenomic and Epigenetic Unit, IRCCS Regina Elena National Cancer Institute, Via Elio Chianesi 53, 00144 Rome, Italy;
| | - Erica Salvati
- Institute of Molecular Biology and Pathology, National Research Council, Rome, Italy, c/o Department of Biology and Biotechnology, Sapienza University of Rome, Via degli Apuli 4, 00185 Rome, Italy;
- Correspondence:
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9
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Hames-Fathi S, Nottley SWG, Pillay N. Unravelling undifferentiated soft tissue sarcomas: insights from genomics. Histopathology 2021; 80:109-121. [DOI: 10.1111/his.14446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Accepted: 07/08/2021] [Indexed: 11/28/2022]
Affiliation(s)
- Shadi Hames-Fathi
- Research Department of Pathology University College London UCL Cancer Institute LondonUK
| | - Steven W G Nottley
- Research Department of Pathology University College London UCL Cancer Institute LondonUK
| | - Nischalan Pillay
- Research Department of Pathology University College London UCL Cancer Institute LondonUK
- Department of Cellular and Molecular Pathology Royal National Orthopaedic Hospital NHS Trust Stanmore UK
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10
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Stainczyk SA, Westermann F. Neuroblastoma-Telomere maintenance, deregulated signaling transduction and beyond. Int J Cancer 2021; 150:903-915. [PMID: 34636058 DOI: 10.1002/ijc.33839] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 09/06/2021] [Accepted: 09/27/2021] [Indexed: 11/11/2022]
Abstract
The childhood malignancy neuroblastoma belongs to the group of embryonal tumors and originates from progenitor cells of the sympathoadrenal lineage. Treatment options for children with high-risk and relapsed disease are still very limited. In recent years, an ever-growing molecular diversity was identified using (epi)-genetic profiling of neuroblastoma tumors, indicating that molecularly targeted therapies could be a promising therapeutic option. In this review article, we summarize the various molecular subtypes and genetic events associated with neuroblastoma and describe recent advances in targeted therapies. We lay a strong emphasis on the importance of telomere maintenance mechanisms for understanding tumor progression and risk classification of neuroblastoma.
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Affiliation(s)
- Sabine A Stainczyk
- Hopp Children's Cancer Center (KiTZ), Heidelberg, Germany.,Neuroblastoma Genomics, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Frank Westermann
- Hopp Children's Cancer Center (KiTZ), Heidelberg, Germany.,Neuroblastoma Genomics, German Cancer Research Center (DKFZ), Heidelberg, Germany
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11
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Targeting of Telomeric Repeat-Containing RNA G-Quadruplexes: From Screening to Biophysical and Biological Characterization of a New Hit Compound. Int J Mol Sci 2021; 22:ijms221910315. [PMID: 34638655 PMCID: PMC8508872 DOI: 10.3390/ijms221910315] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 09/10/2021] [Accepted: 09/22/2021] [Indexed: 12/19/2022] Open
Abstract
DNA G-quadruplex (G4) structures, either within gene promoter sequences or at telomeres, have been extensively investigated as potential small-molecule therapeutic targets. However, although G4s forming at the telomeric DNA have been extensively investigated as anticancer targets, few studies focus on the telomeric repeat-containing RNA (TERRA), transcribed from telomeres, as potential pharmacological targets. Here, a virtual screening approach to identify a library of drug-like putative TERRA G4 binders, in tandem with circular dichroism melting assay to study their TERRA G4-stabilizing properties, led to the identification of a new hit compound. The affinity of this compound for TERRA RNA and some DNA G4s was analyzed through several biophysical techniques and its biological activity investigated in terms of antiproliferative effect, DNA damage response (DDR) activation, and TERRA RNA expression in high vs. low TERRA-expressing human cancer cells. The selected hit showed good affinity for TERRA G4 and no binding to double-stranded DNA. In addition, biological assays showed that this compound is endowed with a preferential cytotoxic effect on high TERRA-expressing cells, where it induces a DDR at telomeres, probably by displacing TERRA from telomeres. Our studies demonstrate that the identification of TERRA G4-targeting drugs with potential pharmacological effects is achievable, shedding light on new perspectives aimed at discovering new anticancer agents targeting these G4 structures.
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12
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Functional characterization of miR-708 microRNA in telomerase positive and negative human cancer cells. Sci Rep 2021; 11:17052. [PMID: 34426596 PMCID: PMC8382839 DOI: 10.1038/s41598-021-96096-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Accepted: 07/29/2021] [Indexed: 02/07/2023] Open
Abstract
Activation of a telomere length maintenance mechanism (TMM), including telomerase and alternative lengthening of telomeres (ALT), is essential for replicative immortality of tumor cells, although its regulatory mechanisms are incompletely understood. We conducted a microRNA (miRNA) microarray analysis on isogenic telomerase positive (TEP) and ALT cancer cell lines. Amongst nine miRNAs that showed difference in their expression in TEP and ALT cancer cells in array analysis, miR-708 was selected for further analysis since it was consistently highly expressed in a large panel of ALT cells. miR-708 in TEP and ALT cancer cells was not correlated with C-circle levels, an established feature of ALT cells. Its overexpression induced suppression of cell migration, invasion, and angiogenesis in both TEP and ALT cells, although cell proliferation was inhibited only in TEP cells suggesting that ALT cells may have acquired the ability to escape inhibition of cell proliferation by sustained miR-708 overexpression. Further, cell proliferation regulation in TEP cells by miR708 appears to be through the CARF-p53 pathway. We demonstrate here that miR-708 (i) is the first miRNA shown to be differentially regulated in TEP and ALT cancer cells, (ii) possesses tumor suppressor function, and (iii) deregulates CARF and p21WAF1-mediated signaling to limit proliferation in TEP cells.
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13
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Yang SY, Chang EYC, Lim J, Kwan HH, Monchaud D, Yip S, Stirling PC, Wong JMY. G-quadruplexes mark alternative lengthening of telomeres. NAR Cancer 2021; 3:zcab031. [PMID: 34316718 PMCID: PMC8294677 DOI: 10.1093/narcan/zcab031] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Revised: 06/29/2021] [Accepted: 07/05/2021] [Indexed: 11/12/2022] Open
Abstract
About 10-15% of all human cancer cells employ a telomerase-independent recombination-based telomere maintenance method, known as alternative lengthening of telomere (ALT), of which the full mechanism remains incompletely understood. While implicated in previous studies as the initiating signals for ALT telomere repair, the prevalence of non-canonical nucleic acid structures in ALT cancers remains unclear. Extending earlier reports, we observe higher levels of DNA/RNA hybrids (R-loops) in ALT-positive (ALT+) compared to telomerase-positive (TERT+) cells. Strikingly, we observe even more pronounced differences for an associated four-stranded nucleic acid structure, G-quadruplex (G4). G4 signals are found at the telomere and are broadly associated with telomere length and accompanied by DNA damage markers. We establish an interdependent relationship between ALT-associated G4s and R-loops and confirm that these two structures can be spatially linked into unique structures, G-loops, at the telomere. Additionally, stabilization of G4s and R-loops cooperatively enhances ALT-activity. However, co-stabilization at higher doses resulted in cytotoxicity in a synergistic manner. Nuclear G4 signals are significantly and reproducibly different between ALT+ and TERT+ low-grade glioma tumours. Together, we present G4 as a novel hallmark of ALT cancers with potential future applications as a convenient biomarker for identifying ALT+ tumours and as therapeutic targets.
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Affiliation(s)
- Sunny Y Yang
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, V6T 1Z3, Canada
| | | | - Joanne Lim
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, V6T 1Z3, Canada
| | - Harwood H Kwan
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, V6T 1Z3, Canada
| | - David Monchaud
- Institut de Chimie Moléculaire, ICMUB CNRS UMR 6302, UBFC Dijon, 21078 Dijon, France
| | - Stephen Yip
- Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, V6T 2B5 Canada
| | | | - Judy M Y Wong
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, V6T 1Z3, Canada
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da Silva GG, Morais KS, Arcanjo DS, de Oliveira DM. Clinical Relevance of Alternative Lengthening of Telomeres in Cancer. Curr Top Med Chem 2020; 20:485-497. [PMID: 31924155 DOI: 10.2174/1568026620666200110112854] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2019] [Revised: 12/11/2019] [Accepted: 12/16/2019] [Indexed: 11/22/2022]
Abstract
The alternative lengthening of telomere (ALT) is a pathway responsible for cell immortalization in some kinds of tumors. Since the first description of ALT is relatively recent in the oncology field, its mechanism remains elusive, but recent works address ALT-related proteins or cellular structures as potential druggable targets for more specific and efficient antitumor therapies. Moreover, some new generation compounds for antitelomerase therapy in cancer were able to provoke acquisition of ALT phenotype in treated tumors, enhancing the importance of studies on this alternative lengthening of the telomere. However, ALT has been implicated in different - sometimes opposite - outcomes, according to the tumor type studied. Then, in order to design and develop new drugs for ALT+ cancer in an effective way, it is crucial to understand its clinical implications. In this review, we gathered works published in the last two decades to highlight the clinical relevance of ALT on oncology.
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Affiliation(s)
- Guilherme G da Silva
- Department of Biological Basis of Health Sciences, University of Brasilia, Ceilandia Campus, Federal District, Brazil
| | - Karollyne S Morais
- Laboratory of Molecular Pathology of Cancer, University of Brasilia, Federal District, Brazil
| | - Daniel S Arcanjo
- Department of Biological Basis of Health Sciences, University of Brasilia, Ceilandia Campus, Federal District, Brazil
| | - Diêgo M de Oliveira
- Department of Biological Basis of Health Sciences, University of Brasilia, Ceilandia Campus, Federal District, Brazil.,Laboratory of Molecular Pathology of Cancer, University of Brasilia, Federal District, Brazil
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15
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TCGA Pan-Cancer Genomic Analysis of Alternative Lengthening of Telomeres (ALT) Related Genes. Genes (Basel) 2020; 11:genes11070834. [PMID: 32708340 PMCID: PMC7397314 DOI: 10.3390/genes11070834] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 07/15/2020] [Accepted: 07/15/2020] [Indexed: 02/06/2023] Open
Abstract
Telomere maintenance mechanisms (TMM) are used by cancer cells to avoid apoptosis, 85–90% reactivate telomerase, while 10–15% use the alternative lengthening of telomeres (ALT). Due to anti-telomerase-based treatments, some tumors switch from a telomerase-dependent mechanism to ALT; in fact, the co-existence between both mechanisms has been observed in some cancers. Although different elements in the ALT pathway are uncovered, some molecular mechanisms are still poorly understood. Therefore, with the aim to identify potential molecular markers for the study of ALT, we combined in silico approaches in a 411 telomere maintenance gene set. As a consequence, we conducted a genomic analysis of these genes in 31 Pan-Cancer Atlas studies from The Cancer Genome Atlas and found 325,936 genomic alterations; from which, we identified 20 genes highly mutated in the cancer studies. Finally, we made a protein-protein interaction network and enrichment analysis to observe the main pathways of these genes and discuss their role in ALT-related processes, like homologous recombination and homology directed repair. Overall, due to the lack of understanding of the molecular mechanisms of ALT cancers, we proposed a group of genes, which after ex vivo validations, could represent new potential therapeutic markers in the study of ALT.
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16
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George SL, Parmar V, Lorenzi F, Marshall LV, Jamin Y, Poon E, Angelini P, Chesler L. Novel therapeutic strategies targeting telomere maintenance mechanisms in high-risk neuroblastoma. J Exp Clin Cancer Res 2020; 39:78. [PMID: 32375866 PMCID: PMC7201617 DOI: 10.1186/s13046-020-01582-2] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Accepted: 04/22/2020] [Indexed: 12/13/2022] Open
Abstract
The majority of high-risk neuroblastomas can be divided into three distinct molecular subgroups defined by the presence of MYCN amplification, upstream TERT rearrangements or alternative lengthening of telomeres (ALT). The common defining feature of all three subgroups is altered telomere maintenance; MYCN amplification and upstream TERT rearrangements drive high levels of telomerase expression whereas ALT is a telomerase independent telomere maintenance mechanism. As all three telomere maintenance mechanisms are independently associated with poor outcomes, the development of strategies to selectively target either telomerase expressing or ALT cells holds great promise as a therapeutic approach that is applicable to the majority of children with aggressive disease.Here we summarise the biology of telomere maintenance and the molecular drivers of aggressive neuroblastoma before describing the most promising therapeutic strategies to target both telomerase expressing and ALT cancers. For telomerase-expressing neuroblastoma the most promising targeted agent to date is 6-thio-2'-deoxyguanosine, however clinical development of this agent is required. In osteosarcoma cell lines with ALT, selective sensitivity to ATR inhibition has been reported. However, we present data showing that in fact ALT neuroblastoma cells are more resistant to the clinical ATR inhibitor AZD6738 compared to other neuroblastoma subtypes. More recently a number of additional candidate compounds have been shown to show selectivity for ALT cancers, such as Tetra-Pt (bpy), a compound targeting the telomeric G-quadruplex and pifithrin-α, a putative p53 inhibitor. Further pre-clinical evaluation of these compounds in neuroblastoma models is warranted.In summary, telomere maintenance targeting strategies offer a significant opportunity to develop effective new therapies, applicable to a large proportion of children with high-risk neuroblastoma. In parallel to clinical development, more pre-clinical research specifically for neuroblastoma is urgently needed, if we are to improve survival for this common poor outcome tumour of childhood.
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Affiliation(s)
- S L George
- Paediatric Tumour Biology, Division of Clinical Studies, The Institute of Cancer Research, London, UK.
- Children and Young People's Unit, Royal Marsden NHS Foundation Trust, London, UK.
| | - V Parmar
- Children and Young People's Unit, Royal Marsden NHS Foundation Trust, London, UK
| | - F Lorenzi
- Paediatric Tumour Biology, Division of Clinical Studies, The Institute of Cancer Research, London, UK
| | - L V Marshall
- Paediatric Tumour Biology, Division of Clinical Studies, The Institute of Cancer Research, London, UK
- Children and Young People's Unit, Royal Marsden NHS Foundation Trust, London, UK
| | - Y Jamin
- Division of Radiotherapy and Imaging, The Institute of Cancer Research, London, UK
| | - E Poon
- Paediatric Tumour Biology, Division of Clinical Studies, The Institute of Cancer Research, London, UK
| | - P Angelini
- Children and Young People's Unit, Royal Marsden NHS Foundation Trust, London, UK
| | - L Chesler
- Paediatric Tumour Biology, Division of Clinical Studies, The Institute of Cancer Research, London, UK
- Children and Young People's Unit, Royal Marsden NHS Foundation Trust, London, UK
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17
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The Role of Alternative Lengthening of Telomeres Mechanism in Cancer: Translational and Therapeutic Implications. Cancers (Basel) 2020; 12:cancers12040949. [PMID: 32290440 PMCID: PMC7226354 DOI: 10.3390/cancers12040949] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Revised: 04/09/2020] [Accepted: 04/10/2020] [Indexed: 12/17/2022] Open
Abstract
Telomere maintenance mechanisms (i.e., telomerase activity (TA) and the alternative lengthening of telomere (ALT) mechanism) contribute to tumorigenesis by providing unlimited proliferative capacity to cancer cells. Although the role of either telomere maintenance mechanisms seems to be equivalent in providing a limitless proliferative ability to tumor cells, the contribution of TA and ALT to the clinical outcome of patients may differ prominently. In addition, several strategies have been developed to interfere with TA in cancer, including Imetelstat that has been the first telomerase inhibitor tested in clinical trials. Conversely, the limited information available on the molecular underpinnings of ALT has hindered thus far the development of genuine ALT-targeting agents. Moreover, whether anti-telomerase therapies may be hampered or not by possible adaptive responses is still debatable. Nonetheless, it is plausible hypothesizing that treatment with telomerase inhibitors may exert selective pressure for the emergence of cancer cells that become resistant to treatment by activating the ALT mechanism. This notion, together with the evidence that both telomere maintenance mechanisms may coexist within the same tumor and may distinctly impinge on patients' outcomes, suggests that ALT may exert an unexpected role in tumor biology that still needs to be fully elucidated.
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18
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Abstract
Neuroblastoma is the most common extracranial solid tumor of childhood with a median age of presentation of 17 months. A common theme in high-risk neuroblastoma is maintenance of telomeres, one mechanism for which involves alternate lengthening of telomeres (ALT) associated with ATRX gene mutations. Mutations are believed to result in loss of ATRX protein, and therefore immunohistochemistry is used to detect mutations. We screened 133 cases of neuroblastoma by ATRX immunohistochemistry, and found 9 cases with partial to total absence of ATRX. Sequencing for ATRX mutations detected a mutation in 1 of 9 cases, suggesting immunostaining was not reliable for detecting mutations. To correlate immunostaining with ALT, fluorescence in situ hybridization (FISH) for ALT was performed in 6 of these cases and 5 (from 4 patients) showed ALT, implying impaired ATRX protein function, despite the failure to identify a mutation. Two other cases with large deletions in the ATRX gene showed diffusely positive staining for ATRX protein but showed ALT by FISH. Four of the 6 patients with ALT-positive tumors were over 5 years old. Therefore, 29 additional patients 5 years old and above with ATRX-positive tumors were screened for ALT by FISH and 6 additional cases with ALT were detected, bringing the total to 29% (10/34) of children 5 years old and above, 70% of which showed positive ATRX immunohistochemistry. Patients with ATRX mutations in neuroblastoma tend to have a more chronic and progressive course of disease. Screening neuroblastoma tumors at diagnosis for ATRX mutations may help identify patients who might benefit from personalized therapy directed against ALT. However, relaying on negative immunohistochemistry for ATRX protein to identify ALT in neuroblastoma may miss a significant proportion of patients. The addition of FISH for ALT as part of the diagnostic workup, especially for older children (5 y old and above), would help ensure that patients are correctly identified for anti-ALT therapy.
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19
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Idilli AI, Cusanelli E, Pagani F, Berardinelli F, Bernabé M, Cayuela ML, Poliani PL, Mione MC. Expression of tert Prevents ALT in Zebrafish Brain Tumors. Front Cell Dev Biol 2020; 8:65. [PMID: 32117990 PMCID: PMC7026139 DOI: 10.3389/fcell.2020.00065] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Accepted: 01/23/2020] [Indexed: 12/15/2022] Open
Abstract
The activation of a telomere maintenance mechanism (TMM) is an essential step in cancer progression to escape replicative senescence and apoptosis. Alternative lengthening of telomeres (ALT) is found in a subset of malignant brain tumors with poor outcomes. Here, we describe a model of juvenile zebrafish brain tumor that progressively develops ALT. We discovered that reduced expression of tert, linked to a widespread hypomethylation of the tert promoter and increase in Terra expression precedes ALT development. Surprisingly, expression of tert during juvenile brain tumor development led to reduced proliferation of tumor cells and prolonged survival. Most importantly, expression of tert reverted all ALT features and normalizes TERRA expression, promoted heterochromatin formation at telomeres, and attenuated telomeric DNA damage. These data suggest that the activity of telomerase goes beyond telomere maintenance and has profound consequences on genome stability.
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Affiliation(s)
- Aurora Irene Idilli
- Department of Cellular, Computational and Integrative Biology - CIBIO, University of Trento, Trento, Italy
| | - Emilio Cusanelli
- Department of Cellular, Computational and Integrative Biology - CIBIO, University of Trento, Trento, Italy
| | - Francesca Pagani
- Pathology, Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy
| | | | - Manuel Bernabé
- Telomerase, Cancer and Aging, Department of Surgery, Instituto Murciano de Investigación Biosanitaria-Arrixaca, Murcia, Spain
| | - María Luisa Cayuela
- Telomerase, Cancer and Aging, Department of Surgery, Instituto Murciano de Investigación Biosanitaria-Arrixaca, Murcia, Spain
| | - Pietro Luigi Poliani
- Pathology, Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy
| | - Maria Caterina Mione
- Department of Cellular, Computational and Integrative Biology - CIBIO, University of Trento, Trento, Italy
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20
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Sommer A, Royle NJ. ALT: A Multi-Faceted Phenomenon. Genes (Basel) 2020; 11:E133. [PMID: 32012790 PMCID: PMC7073516 DOI: 10.3390/genes11020133] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 01/17/2020] [Accepted: 01/22/2020] [Indexed: 01/13/2023] Open
Abstract
One of the hallmarks of cancer cells is their indefinite replicative potential, made possible by the activation of a telomere maintenance mechanism (TMM). The majority of cancers reactivate the reverse transcriptase, telomerase, to maintain their telomere length but a minority (10% to 15%) utilize an alternative lengthening of telomeres (ALT) pathway. Here, we review the phenotypes and molecular markers specific to ALT, and investigate the significance of telomere mutations and sequence variation in ALT cell lines. We also look at the recent advancements in understanding the different mechanisms behind ALT telomere elongation and finally, the progress made in identifying potential ALT-targeted therapies, including those already in use for the treatment of both hematological and solid tumors.
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Affiliation(s)
| | - Nicola J. Royle
- Department of Genetics and Genome Biology, University of Leicester, Leicester LE1 7RH, UK;
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21
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Giangaspero F, Minasi S, Gianno F, Alzoubi H, Antonelli M, Buttarelli F. Mechanisms of telomere maintenance in pediatric brain tumors: Promising targets for therapy – A narrative review. GLIOMA 2020. [DOI: 10.4103/glioma.glioma_20_20] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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22
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Jimenez PC, Wilke DV, Branco PC, Bauermeister A, Rezende‐Teixeira P, Gaudêncio SP, Costa‐Lotufo LV. Enriching cancer pharmacology with drugs of marine origin. Br J Pharmacol 2020; 177:3-27. [PMID: 31621891 PMCID: PMC6976878 DOI: 10.1111/bph.14876] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 08/13/2019] [Accepted: 09/05/2019] [Indexed: 12/29/2022] Open
Abstract
Marine natural products have proven, over the last half-century, to be effective biological modulators. These molecules have revealed new targets for cancer therapy as well as dissimilar modes of action within typical classes of drugs. In this scenario, innovation from marine-based pharmaceuticals has helped advance cancer chemotherapy in many aspects, as most of these are designated as first-in-class drugs. Here, by examining the path from discovery to development of clinically approved drugs of marine origin for cancer treatment-cytarabine (Cytosar-U®), trabectedin (Yondelis®), eribulin (Halaven®), brentuximab vedotin (Adcetris®), and plitidepsin (Aplidin®)- together with those in late clinical trial phases-lurbinectedin, plinabulin, marizomib, and plocabulin-the present review offers a critical analysis of the contributions given by these new compounds to cancer pharmacotherapy.
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Affiliation(s)
- Paula C. Jimenez
- Departamento de Ciências do MarUniversidade Federal de São PauloSantosSPBrasil
| | - Diego V. Wilke
- Núcleo de Pesquisa e Desenvolvimento de Medicamentos (NPDM), Departamento de Fisiologia e Farmacologia, Faculdade de MedicinaUniversidade Federal do CearáFortalezaCEBrasil
| | - Paola C. Branco
- Departamento de Farmacologia, Instituto de Ciências BiomédicasUniversidade de São PauloSão PauloSPBrasil
| | - Anelize Bauermeister
- Departamento de Farmacologia, Instituto de Ciências BiomédicasUniversidade de São PauloSão PauloSPBrasil
| | - Paula Rezende‐Teixeira
- Departamento de Farmacologia, Instituto de Ciências BiomédicasUniversidade de São PauloSão PauloSPBrasil
| | - Susana P. Gaudêncio
- UCIBIO, Department of Chemistry, Blue Biotechnology and Biomedicine Lab, Faculty of Science and TechnologyNOVA University of LisbonCaparicaPortugal
| | - Leticia V. Costa‐Lotufo
- Departamento de Farmacologia, Instituto de Ciências BiomédicasUniversidade de São PauloSão PauloSPBrasil
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23
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Zhao S, Wang F, Liu L. Alternative Lengthening of Telomeres (ALT) in Tumors and Pluripotent Stem Cells. Genes (Basel) 2019; 10:genes10121030. [PMID: 31835618 PMCID: PMC6947546 DOI: 10.3390/genes10121030] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 11/28/2019] [Accepted: 12/02/2019] [Indexed: 12/22/2022] Open
Abstract
A telomere consists of repeated DNA sequences (TTAGGG)n as part of a nucleoprotein structure at the end of the linear chromosome, and their progressive shortening induces DNA damage response (DDR) that triggers cellular senescence. The telomere can be maintained by telomerase activity (TA) in the majority of cancer cells (particularly cancer stem cells) and pluripotent stem cells (PSCs), which exhibit unlimited self-proliferation. However, some cells, such as telomerase-deficient cancer cells, can add telomeric repeats by an alternative lengthening of the telomeres (ALT) pathway, showing telomere length heterogeneity. In this review, we focus on the mechanisms of the ALT pathway and potential clinical implications. We also discuss the characteristics of telomeres in PSCs, thereby shedding light on the therapeutic significance of telomere length regulation in age-related diseases and regenerative medicine.
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Affiliation(s)
- Shuang Zhao
- College of Life Sciences, Nankai University, Tianjin 300071, China;
- State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin 300071, China
| | - Feng Wang
- Department of Genetics, School of Basic Medical Sciences, Tianjin Medical University, Tianjin 300070, China;
| | - Lin Liu
- College of Life Sciences, Nankai University, Tianjin 300071, China;
- State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin 300071, China
- Correspondence:
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24
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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: 6] [Impact Index Per Article: 1.2] [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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25
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Vaquero-Sedas MI, Vega-Palas MA. Assessing the Epigenetic Status of Human Telomeres. Cells 2019; 8:cells8091050. [PMID: 31500249 PMCID: PMC6770363 DOI: 10.3390/cells8091050] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 08/29/2019] [Accepted: 09/05/2019] [Indexed: 12/21/2022] Open
Abstract
The epigenetic modifications of human telomeres play a relevant role in telomere functions and cell proliferation. Therefore, their study is becoming an issue of major interest. These epigenetic modifications are usually analyzed by microscopy or by chromatin immunoprecipitation (ChIP). However, these analyses could be challenged by subtelomeres and/or interstitial telomeric sequences (ITSs). Whereas telomeres and subtelomeres cannot be differentiated by microscopy techniques, telomeres and ITSs might not be differentiated in ChIP analyses. In addition, ChIP analyses of telomeres should be properly controlled. Hence, studies focusing on the epigenetic features of human telomeres have to be carefully designed and interpreted. Here, we present a comprehensive discussion on how subtelomeres and ITSs might influence studies of human telomere epigenetics. We specially focus on the influence of ITSs and some experimental aspects of the ChIP technique on ChIP analyses. In addition, we propose a specific pipeline to accurately perform these studies. This pipeline is very simple and can be applied to a wide variety of cells, including cancer cells. Since the epigenetic status of telomeres could influence cancer cells proliferation, this pipeline might help design precise epigenetic treatments for specific cancer types.
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Affiliation(s)
- María I Vaquero-Sedas
- Instituto de Bioquímica Vegetal y Fotosíntesis, CSIC-Universidad de Sevilla, 41092 Seville, Spain.
| | - Miguel A Vega-Palas
- Instituto de Bioquímica Vegetal y Fotosíntesis, CSIC-Universidad de Sevilla, 41092 Seville, Spain.
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26
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Cacchione S, Biroccio A, Rizzo A. Emerging roles of telomeric chromatin alterations in cancer. J Exp Clin Cancer Res 2019; 38:21. [PMID: 30654820 PMCID: PMC6337846 DOI: 10.1186/s13046-019-1030-5] [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: 11/22/2018] [Accepted: 01/07/2019] [Indexed: 12/26/2022] Open
Abstract
Telomeres, the nucleoprotein structures that cap the ends of eukaryotic chromosomes, play important and multiple roles in tumorigenesis. Functional telomeres need the establishment of a protective chromatin structure based on the interplay between the specific complex named shelterin and a tight nucleosomal organization. Telomere shortening in duplicating somatic cells leads eventually to the destabilization of the telomere capping structure and to the activation of a DNA damage response (DDR) signaling. The final outcome of this process is cell replicative senescence, which constitute a protective barrier against unlimited proliferation. Cells that can bypass senescence checkpoint continue to divide until a second replicative checkpoint, crisis, characterized by chromosome fusions and rearrangements leading to massive cell death by apoptosis. During crisis telomere dysfunctions can either inhibit cell replication or favor tumorigenesis by the accumulation of chromosomal rearrangements and neoplastic mutations. The acquirement of a telomere maintenance mechanism allows fixing the aberrant phenotype, and gives the neoplastic cell unlimited replicative potential, one of the main hallmarks of cancer.Despite the crucial role that telomeres play in cancer development, little is known about the epigenetic alterations of telomeric chromatin that affect telomere protection and are associated with tumorigenesis. Here we discuss the current knowledge on the role of telomeric chromatin in neoplastic transformation, with a particular focus on H3.3 mutations in alternative lengthening of telomeres (ALT) cancers and sirtuin deacetylases dysfunctions.
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Affiliation(s)
- Stefano Cacchione
- Department of Biology and Biotechnology "Charles Darwin", Sapienza University of Roma, Piazzale Aldo Moro 5, 00185, Rome, Italy.
| | - Annamaria Biroccio
- Oncogenomic and Epigenetic Unit, IRCCS-Regina Elena National Cancer Institute, Via Elio Chianesi 53, 00144, Rome, Italy
| | - Angela Rizzo
- Oncogenomic and Epigenetic Unit, IRCCS-Regina Elena National Cancer Institute, Via Elio Chianesi 53, 00144, Rome, Italy.
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27
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Targeting Cancer through the Epigenetic Features of Telomeric Regions. Trends Cell Biol 2019; 29:281-290. [PMID: 30660503 DOI: 10.1016/j.tcb.2018.12.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Revised: 12/18/2018] [Accepted: 12/20/2018] [Indexed: 12/16/2022]
Abstract
The integrity of the chromatin associated with telomeric regions, which include telomeres and subtelomeres, is essential for telomeres function and cell viability. Whereas human subtelomeres are heterochromatic, telomeres are labeled with euchromatic marks like H4K20me1 and H3K27ac in most commonly studied human cell lines. The epigenetic marks of human telomeric regions influence oncogenic processes. Indeed, different drugs that decrease their genome-wide levels are currently being used or tested in specific cancer therapies. These drugs can challenge cancer by altering the function of key cellular proteins. However, they should also compromise oncogenic processes by modifying the epigenetic landscape of telomeric regions. We believe that studies of telomeric chromatin structure and telomeres dysfunction should help to design epigenetic therapies for cancer treatment.
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28
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Amato J, Platella C, Iachettini S, Zizza P, Musumeci D, Cosconati S, Pagano A, Novellino E, Biroccio A, Randazzo A, Pagano B, Montesarchio D. Tailoring a lead-like compound targeting multiple G-quadruplex structures. Eur J Med Chem 2018; 163:295-306. [PMID: 30529547 DOI: 10.1016/j.ejmech.2018.11.058] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Revised: 10/30/2018] [Accepted: 11/23/2018] [Indexed: 11/27/2022]
Abstract
A focused library of analogs of a lead-like G-quadruplex (G4) targeting compound (4), sharing a furobenzoxazine naphthoquinone core and differing for the pendant groups on the N-atom of the oxazine ring, has been here analyzed with the aim of developing more potent and selective ligands. These molecules have been tested vs. topologically different G4s by the G4-CPG assay, an affinity chromatography-based method for screening putative G4 ligands. The obtained results showed that all these compounds were able to bind several G4 structures, both telomeric and extra-telomeric, thus behaving as multi-target ligands, and two of them fully discriminated G4 vs. duplex DNA. Biological assays proved that almost all the compounds produced effective DNA damage, showing marked antiproliferative effects on tumor cells in the low μM range. Combined analysis of the G4-CPG binding assays and biological data led us to focus on compound S4-5, proved to be less cytotoxic than the parent compound 4 on normal cells. An in-depth biophysical characterization of the binding of S4-5 to different G4s showed that the here identified ligand has higher affinity for the G4s and higher ability to discriminate G4 vs. duplex DNA than 4. Molecular docking studies, in agreement with the NMR data, suggest that S4-5 interacts with the accessible grooves of the target G4 structures, giving clues for its increased G4 vs. duplex selectivity.
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Affiliation(s)
- Jussara Amato
- Department of Pharmacy, University of Naples Federico II, 80131, Naples, Italy
| | - Chiara Platella
- Department of Chemical Sciences, University of Naples Federico II, 80126, Naples, Italy
| | - Sara Iachettini
- Oncogenomic and Epigenetic Unit, IRCCS - Regina Elena National Cancer Institute, 00144 Rome, Italy
| | - Pasquale Zizza
- Oncogenomic and Epigenetic Unit, IRCCS - Regina Elena National Cancer Institute, 00144 Rome, Italy
| | - Domenica Musumeci
- Department of Chemical Sciences, University of Naples Federico II, 80126, Naples, Italy
| | - Sandro Cosconati
- DiSTABiF, Università della Campania Luigi Vanvitelli, 81100, Caserta, Italy
| | - Alessia Pagano
- Department of Pharmacy, University of Naples Federico II, 80131, Naples, Italy
| | - Ettore Novellino
- Department of Pharmacy, University of Naples Federico II, 80131, Naples, Italy
| | - Annamaria Biroccio
- Oncogenomic and Epigenetic Unit, IRCCS - Regina Elena National Cancer Institute, 00144 Rome, Italy
| | - Antonio Randazzo
- Department of Pharmacy, University of Naples Federico II, 80131, Naples, Italy
| | - Bruno Pagano
- Department of Pharmacy, University of Naples Federico II, 80131, Naples, Italy.
| | - Daniela Montesarchio
- Department of Chemical Sciences, University of Naples Federico II, 80126, Naples, Italy.
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