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Denu RA, Dann AM, Keung EZ, Nakazawa MS, Nassif Haddad EF. The Future of Targeted Therapy for Leiomyosarcoma. Cancers (Basel) 2024; 16:938. [PMID: 38473300 PMCID: PMC10930698 DOI: 10.3390/cancers16050938] [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: 01/18/2024] [Revised: 02/19/2024] [Accepted: 02/21/2024] [Indexed: 03/14/2024] Open
Abstract
Leiomyosarcoma (LMS) is an aggressive subtype of soft tissue sarcoma that arises from smooth muscle cells, most commonly in the uterus and retroperitoneum. LMS is a heterogeneous disease with diverse clinical and molecular characteristics that have yet to be fully understood. Molecular profiling has uncovered possible targets amenable to treatment, though this has yet to translate into approved targeted therapies in LMS. This review will explore historic and recent findings from molecular profiling, highlight promising avenues of current investigation, and suggest possible future strategies to move toward the goal of molecularly matched treatment of LMS. We focus on targeting the DNA damage response, the macrophage-rich micro-environment, the PI3K/mTOR pathway, epigenetic regulators, and telomere biology.
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Affiliation(s)
- Ryan A. Denu
- Division of Cancer Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA;
| | - Amanda M. Dann
- Division of Surgical Oncology, Department of Surgery, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA;
| | - Emily Z. Keung
- Department of Surgical Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA;
| | - Michael S. Nakazawa
- Department of Sarcoma Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Elise F. Nassif Haddad
- Department of Sarcoma Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
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2
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Loe TK, Lazzerini Denchi E, Tricola GM, Azeroglu B. ALTercations at telomeres: stress, recombination and extrachromosomal affairs. Biochem Soc Trans 2023; 51:1935-1946. [PMID: 37767563 DOI: 10.1042/bst20230265] [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: 08/11/2023] [Revised: 09/21/2023] [Accepted: 09/22/2023] [Indexed: 09/29/2023]
Abstract
Approximately 15% of human cancers depend on the alternative lengthening of telomeres (ALT) pathway to maintain telomeres and proliferate. Telomeres that are elongated using ALT display unique features raising the exciting prospect of tailored cancer therapies. ALT-mediated telomere elongation shares several features with recombination-based DNA repair. Strikingly, cells that use the ALT pathway display abnormal levels of replication stress at telomeres and accumulate abundant extrachromosomal telomeric DNA. In this review, we examine recent findings that shed light on the ALT mechanisms and the strategies currently available to suppress this telomere elongation mechanism.
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Affiliation(s)
- Taylor K Loe
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA 92037, U.S.A
| | - Eros Lazzerini Denchi
- Laboratory of Genome Integrity, National Cancer Institute, NIH, Bethesda, MD 20892, U.S.A
| | - Gianna M Tricola
- Laboratory of Genome Integrity, National Cancer Institute, NIH, Bethesda, MD 20892, U.S.A
| | - Benura Azeroglu
- Laboratory of Genome Integrity, National Cancer Institute, NIH, Bethesda, MD 20892, U.S.A
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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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de Nonneville A, Salas S, Bertucci F, Sobinoff AP, Adélaïde J, Guille A, Finetti P, Noble JR, Churikov D, Chaffanet M, Lavit E, Pickett HA, Bouvier C, Birnbaum D, Reddel RR, Géli V. TOP3A amplification and ATRX inactivation are mutually exclusive events in pediatric osteosarcomas using ALT. EMBO Mol Med 2022; 14:e15859. [PMID: 35920001 PMCID: PMC9549729 DOI: 10.15252/emmm.202215859] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Revised: 07/13/2022] [Accepted: 07/14/2022] [Indexed: 02/05/2023] Open
Abstract
In some types of cancer, telomere length is maintained by the alternative lengthening of telomeres (ALT) mechanism. In many ALT cancers, the α-thalassemia/mental retardation syndrome X-linked (ATRX) gene is mutated leading to the conclusion that the ATRX complex represses ALT. Here, we report that most high-grade pediatric osteosarcomas maintain their telomeres by ALT, and that the majority of these ALT tumors are ATRX wild-type (wt) and instead carry an amplified 17p11.2 chromosomal region containing TOP3A. We found that TOP3A was overexpressed in the ALT-positive ATRX-wt tumors consistent with its amplification. We demonstrated the functional significance of these results by showing that TOP3A overexpression in ALT cancer cells countered ATRX-mediated ALT inhibition and that TOP3A knockdown disrupted the ALT phenotype in ATRX-wt cells. Moreover, we report that TOP3A is required for proper BLM localization and promotes ALT DNA synthesis in ALT cell lines. Collectively, our results identify TOP3A as a major ALT player and potential therapeutic target.
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Affiliation(s)
- Alexandre de Nonneville
- Marseille Cancer Research Centre (CRCM), Inserm U1068, CNRS UMR7258, Institut Paoli‐Calmettes, Team « Telomere and Chromatin ». Equipe labellisée Ligue Nationale Contre Le CancerAix‐Marseille UnivMarseilleFrance,Cancer Research Unit, Faculty of Medicine and Health, Children's Medical Research InstituteUniversity of SydneyWestmeadNSWAustralia,Predictive Oncology Laboratory, Marseille Cancer Research Centre (CRCM), Inserm U1068, CNRS UMR7258, Institut Paoli‐CalmettesAix‐Marseille UniversityMarseilleFrance,Department of Medical Oncology, CRCM, CNRS, INSERM, Institut Paoli‐CalmettesAix‐Marseille UnivMarseilleFrance
| | - Sébastien Salas
- Department of Medical OncologyAssistance Publique Hôpitaux de Marseille ‐ Timone HospitalMarseilleFrance
| | - François Bertucci
- Predictive Oncology Laboratory, Marseille Cancer Research Centre (CRCM), Inserm U1068, CNRS UMR7258, Institut Paoli‐CalmettesAix‐Marseille UniversityMarseilleFrance,Department of Medical Oncology, CRCM, CNRS, INSERM, Institut Paoli‐CalmettesAix‐Marseille UnivMarseilleFrance
| | - Alexander P Sobinoff
- Telomere Length Regulation Unit, Faculty of Medicine and Health, Children's Medical Research InstituteUniversity of SydneyWestmeadNSWAustralia
| | - José Adélaïde
- Predictive Oncology Laboratory, Marseille Cancer Research Centre (CRCM), Inserm U1068, CNRS UMR7258, Institut Paoli‐CalmettesAix‐Marseille UniversityMarseilleFrance
| | - Arnaud Guille
- Predictive Oncology Laboratory, Marseille Cancer Research Centre (CRCM), Inserm U1068, CNRS UMR7258, Institut Paoli‐CalmettesAix‐Marseille UniversityMarseilleFrance
| | - Pascal Finetti
- Predictive Oncology Laboratory, Marseille Cancer Research Centre (CRCM), Inserm U1068, CNRS UMR7258, Institut Paoli‐CalmettesAix‐Marseille UniversityMarseilleFrance
| | - Jane R Noble
- Cancer Research Unit, Faculty of Medicine and Health, Children's Medical Research InstituteUniversity of SydneyWestmeadNSWAustralia
| | - Dimitri Churikov
- Marseille Cancer Research Centre (CRCM), Inserm U1068, CNRS UMR7258, Institut Paoli‐Calmettes, Team « Telomere and Chromatin ». Equipe labellisée Ligue Nationale Contre Le CancerAix‐Marseille UnivMarseilleFrance
| | - Max Chaffanet
- Predictive Oncology Laboratory, Marseille Cancer Research Centre (CRCM), Inserm U1068, CNRS UMR7258, Institut Paoli‐CalmettesAix‐Marseille UniversityMarseilleFrance
| | - Elise Lavit
- Department of Medical OncologyAssistance Publique Hôpitaux de Marseille ‐ Timone HospitalMarseilleFrance
| | - Hilda A Pickett
- Telomere Length Regulation Unit, Faculty of Medicine and Health, Children's Medical Research InstituteUniversity of SydneyWestmeadNSWAustralia
| | - Corinne Bouvier
- Department of PathologyAssistance Publique Hôpitaux de Marseille ‐ Timone HospitalMarseilleFrance
| | - Daniel Birnbaum
- Predictive Oncology Laboratory, Marseille Cancer Research Centre (CRCM), Inserm U1068, CNRS UMR7258, Institut Paoli‐CalmettesAix‐Marseille UniversityMarseilleFrance
| | - Roger R Reddel
- Cancer Research Unit, Faculty of Medicine and Health, Children's Medical Research InstituteUniversity of SydneyWestmeadNSWAustralia
| | - Vincent Géli
- Marseille Cancer Research Centre (CRCM), Inserm U1068, CNRS UMR7258, Institut Paoli‐Calmettes, Team « Telomere and Chromatin ». Equipe labellisée Ligue Nationale Contre Le CancerAix‐Marseille UnivMarseilleFrance
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5
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Shi Y, Liu G, Wu R, Mack DL, Sun XS, Maxwell J, Guan X, Atala A, Zhang Y. Differentiation Capacity of Human Urine-Derived Stem Cells to Retain Telomerase Activity. Front Cell Dev Biol 2022; 10:890574. [PMID: 35693947 PMCID: PMC9186504 DOI: 10.3389/fcell.2022.890574] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2022] [Accepted: 04/29/2022] [Indexed: 12/12/2022] Open
Abstract
Telomerase activity is essential for the self-renewal and potential of embryonic, induced pluripotent, and cancer stem cells, as well as a few somatic stem cells, such as human urine-derived stem cells (USCs). However, it remains unclear how telomerase activity affects the regeneration potential of somatic stem cells. The objective of this study was to determine the regenerative significance of telomerase activity, particularly to retain cell surface marker expression, multipotent differentiation capability, chromosomal stability, and in vivo tumorigenic transformation, in each clonal population of human primary USCs. In total, 117 USC specimens from 10 healthy male adults (25–57 years of age) were obtained. Polymerase chain reaction amplification of a telomeric repeat was used to detect USCs with positive telomerase activity (USCsTA+). A total of 80 USCsTA+ (70.2%) were identified from 117 USC clones, but they were not detected in the paired normal bladder smooth muscle cell and bone marrow stromal cell specimens. In the 20–40 years age group, approximately 75% of USC clones displayed positive telomerase activity, whereas in the 50 years age group, 59.2% of the USC clones expressed positive telomerase activity. USCsTA+ extended to passage 16, underwent 62.0 ± 4.8 population doublings, produced more cells, and were superior for osteogenic, myogenic, and uroepithelial differentiation compared to USCsTA−. Importantly, USCs displayed normal chromosome and no oncological transformation after being implanted in vivo. Overall, as a safe cell source, telomerase-positive USCs have a robust regenerative potential in cell proliferation and multipotent differentiation capacity.
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Affiliation(s)
- Yingai Shi
- Institute for Regenerative Medicine, Wake Forest University, Winston-Salem, NC, United States
- Key Laboratory of Pathobiology, Ministry of Education, College of Basic Medical Sciences, Jilin University, Jilin, China
| | - Guihua Liu
- Institute for Regenerative Medicine, Wake Forest University, Winston-Salem, NC, United States
- Reproductive Medical Center, Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, China
| | - Rongpei Wu
- Institute for Regenerative Medicine, Wake Forest University, Winston-Salem, NC, United States
- Department of Urology, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, China
| | - David L. Mack
- Institute for Regenerative Medicine, Wake Forest University, Winston-Salem, NC, United States
- Department of Rehabilitation Medicine and Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, WA, United States
| | - Xiuzhi Susan Sun
- Institute for Regenerative Medicine, Wake Forest University, Winston-Salem, NC, United States
- Bio-Materials and Technology Lab, Grain Science and Industry, Bio and Agricultural Engineering, Kansas State University, Kansas, KS, United States
| | - Joshua Maxwell
- Institute for Regenerative Medicine, Wake Forest University, Winston-Salem, NC, United States
| | - Xuan Guan
- Institute for Regenerative Medicine, Wake Forest University, Winston-Salem, NC, United States
- Cardiovascular Disease AdvenHealth Orland, Orland, FL, United States
| | - Anthony Atala
- Institute for Regenerative Medicine, Wake Forest University, Winston-Salem, NC, United States
| | - Yuanyuan Zhang
- Institute for Regenerative Medicine, Wake Forest University, Winston-Salem, NC, United States
- *Correspondence: Yuanyuan Zhang,
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6
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Bhargava R, Lynskey ML, O’Sullivan RJ. New twists to the ALTernative endings at telomeres. DNA Repair (Amst) 2022; 115:103342. [DOI: 10.1016/j.dnarep.2022.103342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 05/02/2022] [Accepted: 05/05/2022] [Indexed: 11/30/2022]
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7
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Subcellular progression of mesenchymal transition identified by two discrete synchronous cell lines derived from the same glioblastoma. Cell Mol Life Sci 2022; 79:181. [PMID: 35278143 PMCID: PMC8918182 DOI: 10.1007/s00018-022-04188-3] [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: 11/16/2021] [Revised: 01/18/2022] [Accepted: 02/04/2022] [Indexed: 11/19/2022]
Abstract
Glioblastomas (GBM) exhibit intratumoral heterogeneity of various oncogenic evolutional processes. We have successfully isolated and established two distinct cancer cell lines with different morphological and biological characteristics that were derived from the same tissue sample of a GBM. When we compared their genomic and transcriptomic characteristics, each cell line harbored distinct mutation clusters while sharing core driver mutations. Transcriptomic analysis revealed that one cell line was undergoing a mesenchymal transition process, unlike the other cell line. Furthermore, we could identify four tumor samples containing our cell line-like clusters from the publicly available single-cell RNA-seq data, and in a set of paired longitudinal GBM samples, we could confirm three pairs where the recurrent sample was enriched in the genes specific to our cell line undergoing mesenchymal transition. The present study provides direct evidence and a valuable source for investigating the ongoing process of subcellular mesenchymal transition in GBM, which has prognostic and therapeutic implications.
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8
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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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9
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Park Y, Park J, Ahn JW, Sim JM, Kang SJ, Kim S, Hwang SJ, Han SH, Sung KS, Lim J. Transcriptomic Landscape of Lower Grade Glioma Based on Age-Related Non-Silent Somatic Mutations. ACTA ACUST UNITED AC 2021; 28:2281-2295. [PMID: 34205437 PMCID: PMC8293196 DOI: 10.3390/curroncol28030210] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 06/06/2021] [Accepted: 06/16/2021] [Indexed: 12/13/2022]
Abstract
Glioma accounts for 80% of all malignant brain tumours and is the most common adult primary brain tumour. Age is an important factor affecting the development of cancer, as somatic mutations accumulate with age. Here, we aimed to analyse the significance of age-dependent non-silent somatic mutations in glioma prognosis. Histological tumour grade depends on age at diagnosis in patients with IDH1, TP53, ATRX, and EGFR mutations. Age of patients with wild-type IDH1 and EGFR increased with increase in tumour grade, while the age of patients with IDH1 or EGFR mutation remained constant. However, the age of patients with EGFR mutation was higher than that of patients with IDH1 mutation. The hierarchical clustering of patients was dominantly separated by IDH1 and EGFR mutations. Furthermore, patients with IDH1 mutation were dominantly separated by TP53 and ATRX double mutation and its double wild-type counterpart. The age of patients with ATRX and TP53 mutation was lower than that of patients with wild-type ATRX and TP53. Patients with the double mutation showed poorer prognosis than those with the double wild type genotype. Unlike IDH1 mutant, IDH1 wild-type showed upregulation of expression of epithelial mesenchymal transition associated genes.
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Affiliation(s)
- YoungJoon Park
- Institute Department of Biomedical Science, College of Life Science, CHA University, Seongnam 13488, Korea; (Y.P.); (J.P.); (J.W.A.); (S.J.K.)
- Department of Neurosurgery, Bundang CHA Medical Center, CHA University College of Medicine, Seongnam 13496, Korea; (J.M.S.); (S.K.); (S.J.H.)
| | - JeongMan Park
- Institute Department of Biomedical Science, College of Life Science, CHA University, Seongnam 13488, Korea; (Y.P.); (J.P.); (J.W.A.); (S.J.K.)
- Department of Neurosurgery, Bundang CHA Medical Center, CHA University College of Medicine, Seongnam 13496, Korea; (J.M.S.); (S.K.); (S.J.H.)
| | - Ju Won Ahn
- Institute Department of Biomedical Science, College of Life Science, CHA University, Seongnam 13488, Korea; (Y.P.); (J.P.); (J.W.A.); (S.J.K.)
- Department of Neurosurgery, Bundang CHA Medical Center, CHA University College of Medicine, Seongnam 13496, Korea; (J.M.S.); (S.K.); (S.J.H.)
| | - Jeong Min Sim
- Department of Neurosurgery, Bundang CHA Medical Center, CHA University College of Medicine, Seongnam 13496, Korea; (J.M.S.); (S.K.); (S.J.H.)
| | - Su Jung Kang
- Institute Department of Biomedical Science, College of Life Science, CHA University, Seongnam 13488, Korea; (Y.P.); (J.P.); (J.W.A.); (S.J.K.)
- Department of Neurosurgery, Bundang CHA Medical Center, CHA University College of Medicine, Seongnam 13496, Korea; (J.M.S.); (S.K.); (S.J.H.)
| | - Suwan Kim
- Department of Neurosurgery, Bundang CHA Medical Center, CHA University College of Medicine, Seongnam 13496, Korea; (J.M.S.); (S.K.); (S.J.H.)
| | - So Jung Hwang
- Department of Neurosurgery, Bundang CHA Medical Center, CHA University College of Medicine, Seongnam 13496, Korea; (J.M.S.); (S.K.); (S.J.H.)
- Global Research Supporting Center, Bundang CHA Medical Center, CHA University College of Medicine, Seongnam 13496, Korea
| | - Song-Hee Han
- Department of Pathology, Dong-A University College of Medicine, Dong-A University, Busan 49201, Korea;
| | - Kyoung Su Sung
- Department of Neurosurgery, Dong-A University Hospital, Dong-A University College of Medicine, Busan 49201, Korea
- Correspondence: or (K.S.S.); or (J.L.); Tel.: +82-51-240-5241 (K.S.S.); +82-31-780-5688 (J.L.)
| | - Jaejoon Lim
- Department of Neurosurgery, Bundang CHA Medical Center, CHA University College of Medicine, Seongnam 13496, Korea; (J.M.S.); (S.K.); (S.J.H.)
- Correspondence: or (K.S.S.); or (J.L.); Tel.: +82-51-240-5241 (K.S.S.); +82-31-780-5688 (J.L.)
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Nersisyan L, Simonyan A, Binder H, Arakelyan A. Telomere Maintenance Pathway Activity Analysis Enables Tissue- and Gene-Level Inferences. Front Genet 2021; 12:662464. [PMID: 33897770 PMCID: PMC8058386 DOI: 10.3389/fgene.2021.662464] [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: 02/01/2021] [Accepted: 03/16/2021] [Indexed: 12/31/2022] Open
Abstract
Telomere maintenance is one of the mechanisms ensuring indefinite divisions of cancer and stem cells. Good understanding of telomere maintenance mechanisms (TMM) is important for studying cancers and designing therapies. However, molecular factors triggering selective activation of either the telomerase dependent (TEL) or the alternative lengthening of telomeres (ALT) pathway are poorly understood. In addition, more accurate and easy-to-use methodologies are required for TMM phenotyping. In this study, we have performed literature based reconstruction of signaling pathways for the ALT and TEL TMMs. Gene expression data were used for computational assessment of TMM pathway activities and compared with experimental assays for TEL and ALT. Explicit consideration of pathway topology makes bioinformatics analysis more informative compared to computational methods based on simple summary measures of gene expression. Application to healthy human tissues showed high ALT and TEL pathway activities in testis, and identified genes and pathways that may trigger TMM activation. Our approach offers a novel option for systematic investigation of TMM activation patterns across cancers and healthy tissues for dissecting pathway-based molecular markers with diagnostic impact.
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Affiliation(s)
- Lilit Nersisyan
- Bioinformatics Group, Institute of Molecular Biology, National Academy of Sciences, Yerevan, Armenia.,Pathverse, Yerevan, Armenia
| | - Arman Simonyan
- Bioinformatics Group, Institute of Molecular Biology, National Academy of Sciences, Yerevan, Armenia
| | - Hans Binder
- Interdisciplinary Center for Bioinformatics, University of Leipzig, Leipzig, Germany
| | - Arsen Arakelyan
- Bioinformatics Group, Institute of Molecular Biology, National Academy of Sciences, Yerevan, Armenia.,Pathverse, Yerevan, Armenia
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11
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Noureen N, Wu S, Lv Y, Yang J, Alfred Yung WK, Gelfond J, Wang X, Koul D, Ludlow A, Zheng S. Integrated analysis of telomerase enzymatic activity unravels an association with cancer stemness and proliferation. Nat Commun 2021; 12:139. [PMID: 33420056 PMCID: PMC7794223 DOI: 10.1038/s41467-020-20474-9] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 12/03/2020] [Indexed: 12/11/2022] Open
Abstract
Active telomerase is essential for stem cells and most cancers to maintain telomeres. The enzymatic activity of telomerase is related but not equivalent to the expression of TERT, the catalytic subunit of the complex. Here we show that telomerase enzymatic activity can be robustly estimated from the expression of a 13-gene signature. We demonstrate the validity of the expression-based approach, named EXTEND, using cell lines, cancer samples, and non-neoplastic samples. When applied to over 9,000 tumors and single cells, we find a strong correlation between telomerase activity and cancer stemness. This correlation is largely driven by a small population of proliferating cancer cells that exhibits both high telomerase activity and cancer stemness. This study establishes a computational framework for quantifying telomerase enzymatic activity and provides new insights into the relationships among telomerase, cancer proliferation, and stemness.
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Affiliation(s)
- Nighat Noureen
- Greehey Children's Cancer Research Institute, UT Health San Antonio, San Antonio, TX, USA
- Department of Population Health Sciences, UT Health San Antonio, San Antonio, TX, USA
| | - Shaofang Wu
- Department of Neuro-Oncology, MD Anderson Cancer Center, Houston, TX, USA
| | - Yingli Lv
- Greehey Children's Cancer Research Institute, UT Health San Antonio, San Antonio, TX, USA
| | - Juechen Yang
- Greehey Children's Cancer Research Institute, UT Health San Antonio, San Antonio, TX, USA
| | - W K Alfred Yung
- Department of Neuro-Oncology, MD Anderson Cancer Center, Houston, TX, USA
| | - Jonathan Gelfond
- Department of Population Health Sciences, UT Health San Antonio, San Antonio, TX, USA
| | - Xiaojing Wang
- Greehey Children's Cancer Research Institute, UT Health San Antonio, San Antonio, TX, USA
- Department of Population Health Sciences, UT Health San Antonio, San Antonio, TX, USA
| | - Dimpy Koul
- Department of Neuro-Oncology, MD Anderson Cancer Center, Houston, TX, USA
| | - Andrew Ludlow
- Department of Movement Science, University of Michigan, Ann Arbor, MI, USA
| | - Siyuan Zheng
- Greehey Children's Cancer Research Institute, UT Health San Antonio, San Antonio, TX, USA.
- Department of Population Health Sciences, UT Health San Antonio, San Antonio, TX, USA.
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12
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Olatz C, Patricia GG, Jon L, Iker B, Carmen DLH, Fernando U, Gaskon I, Ramon PJ. Is There Such a Thing as a Genuine Cancer Stem Cell Marker? Perspectives from the Gut, the Brain and the Dental Pulp. BIOLOGY 2020; 9:biology9120426. [PMID: 33260962 PMCID: PMC7760753 DOI: 10.3390/biology9120426] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 11/24/2020] [Accepted: 11/26/2020] [Indexed: 12/24/2022]
Abstract
The conversion of healthy stem cells into cancer stem cells (CSCs) is believed to underlie tumor relapse after surgical removal and fuel tumor growth and invasiveness. CSCs often arise from the malignant transformation of resident multipotent stem cells, which are present in most human tissues. Some organs, such as the gut and the brain, can give rise to very aggressive types of cancers, contrary to the dental pulp, which is a tissue with a very remarkable resistance to oncogenesis. In this review, we focus on the similarities and differences between gut, brain and dental pulp stem cells and their related CSCs, placing a particular emphasis on both their shared and distinctive cell markers, including the expression of pluripotency core factors. We discuss some of their similarities and differences with regard to oncogenic signaling, telomerase activity and their intrinsic propensity to degenerate to CSCs. We also explore the characteristics of the events and mutations leading to malignant transformation in each case. Importantly, healthy dental pulp stem cells (DPSCs) share a great deal of features with many of the so far reported CSC phenotypes found in malignant neoplasms. However, there exist literally no reports about the contribution of DPSCs to malignant tumors. This raises the question about the particularities of the dental pulp and what specific barriers to malignancy might be present in the case of this tissue. These notable differences warrant further research to decipher the singular properties of DPSCs that make them resistant to transformation, and to unravel new therapeutic targets to treat deadly tumors.
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Affiliation(s)
- Crende Olatz
- Department of Cell Biology and Histology, Faculty of Medicine and Nursing, University of the Basque Country (UPV/EHU), 48940 Leioa, Spain; (C.O.); (G.-G.P.); (L.J.); (B.I.); (d.l.H.C.); (U.F.)
| | - García-Gallastegui Patricia
- Department of Cell Biology and Histology, Faculty of Medicine and Nursing, University of the Basque Country (UPV/EHU), 48940 Leioa, Spain; (C.O.); (G.-G.P.); (L.J.); (B.I.); (d.l.H.C.); (U.F.)
| | - Luzuriaga Jon
- Department of Cell Biology and Histology, Faculty of Medicine and Nursing, University of the Basque Country (UPV/EHU), 48940 Leioa, Spain; (C.O.); (G.-G.P.); (L.J.); (B.I.); (d.l.H.C.); (U.F.)
| | - Badiola Iker
- Department of Cell Biology and Histology, Faculty of Medicine and Nursing, University of the Basque Country (UPV/EHU), 48940 Leioa, Spain; (C.O.); (G.-G.P.); (L.J.); (B.I.); (d.l.H.C.); (U.F.)
| | - de la Hoz Carmen
- Department of Cell Biology and Histology, Faculty of Medicine and Nursing, University of the Basque Country (UPV/EHU), 48940 Leioa, Spain; (C.O.); (G.-G.P.); (L.J.); (B.I.); (d.l.H.C.); (U.F.)
| | - Unda Fernando
- Department of Cell Biology and Histology, Faculty of Medicine and Nursing, University of the Basque Country (UPV/EHU), 48940 Leioa, Spain; (C.O.); (G.-G.P.); (L.J.); (B.I.); (d.l.H.C.); (U.F.)
| | - Ibarretxe Gaskon
- Department of Cell Biology and Histology, Faculty of Medicine and Nursing, University of the Basque Country (UPV/EHU), 48940 Leioa, Spain; (C.O.); (G.-G.P.); (L.J.); (B.I.); (d.l.H.C.); (U.F.)
- Correspondence: (I.G.); (P.J.R.); Tel.: +34-946-013-218 (I.G.); +34-946-012-426 (P.J.R.)
| | - Pineda Jose Ramon
- Department of Cell Biology and Histology, Faculty of Medicine and Nursing, University of the Basque Country (UPV/EHU), 48940 Leioa, Spain; (C.O.); (G.-G.P.); (L.J.); (B.I.); (d.l.H.C.); (U.F.)
- Achucarro Basque Center for Neuroscience Fundazioa, 48940 Leioa, Spain
- Correspondence: (I.G.); (P.J.R.); Tel.: +34-946-013-218 (I.G.); +34-946-012-426 (P.J.R.)
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13
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Lee KH, Kimmel M. Analysis of two mechanisms of telomere maintenance based on the theory of g-Networks and stochastic automata networks. BMC Genomics 2020; 21:587. [PMID: 32900359 PMCID: PMC7488072 DOI: 10.1186/s12864-020-06937-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
* Background Telomeres, which are composed of repetitive nucleotide sequences at the end of chromosomes, behave as a division clock that measures replicative senescence. Under the normal physiological condition, telomeres shorten with each cell division, and cells use the telomere lengths to sense the number of divisions. Replicative senescence has been shown to occur at approximately 50–70 cell divisions, which is termed the Hayflick’s limit. However, in cancer cells telomere lengths are stabilized, thereby allowing continual cell replication by two known mechanisms: activation of telomerase and Alternative Lengthening of Telomeres (ALT). The connections between the two mechanisms are complicated and still poorly understood. * Results In this research, we propose that two different approaches, G-Networks and Stochastic Automata Networks, which are stochastic models motivated by queueing theory, are useful to identify a set of genes that play an important role in the state of interest and to infer their previously unknown correlation by obtaining both stationary and joint transient distributions of the given system. Our analysis using G-Network detects five statistically significant genes (CEBPA, FOXM1, E2F1, c-MYC, hTERT) with either mechanism, contrasted to normal cells. A new algorithm is introduced to show how the correlation between two genes of interest varies in the transient state according not only to each mechanism but also to each cell condition. * Conclusions This study expands our existing knowledge of genes associated with mechanisms of telomere maintenance and provides a platform to understand similarities and differences between telomerase and ALT in terms of the correlation between two genes in the system. This is particularly important because telomere dynamics plays a major role in many physiological and disease processes, including hematopoiesis.
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Affiliation(s)
- Kyung Hyun Lee
- Department of Statistics, Rice University, 6100 Main Street, Houston, 77057, TX, USA
| | - Marek Kimmel
- Department of Statistics, Rice University, 6100 Main Street, Houston, 77057, TX, USA. .,Department of Systems Biology and Engineering Silesian University of Technology, Akademicka 16, Gliwice, 44-100, Poland.
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14
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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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15
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Thompson CA, Wong JM. Non-canonical Functions of Telomerase Reverse Transcriptase: Emerging Roles and Biological Relevance. Curr Top Med Chem 2020; 20:498-507. [DOI: 10.2174/1568026620666200131125110] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Revised: 01/10/2020] [Accepted: 01/21/2020] [Indexed: 12/11/2022]
Abstract
Increasing evidence from research on telomerase suggests that in addition to its catalytic telomere
repeat synthesis activity, telomerase may have other biologically important functions. The canonical
roles of telomerase are at the telomere ends where they elongate telomeres and maintain genomic
stability and cellular lifespan. The catalytic protein component Telomerase Reverse Transcriptase
(TERT) is preferentially expressed at high levels in cancer cells despite the existence of an alternative
mechanism for telomere maintenance (alternative lengthening of telomeres or ALT). TERT is also expressed
at higher levels than necessary for maintaining functional telomere length, suggesting other possible
adaptive functions. Emerging non-canonical roles of TERT include regulation of non-telomeric
DNA damage responses, promotion of cell growth and proliferation, acceleration of cell cycle kinetics,
and control of mitochondrial integrity following oxidative stress. Non-canonical activities of TERT primarily
show cellular protective effects, and nuclear TERT has been shown to protect against cell death
following double-stranded DNA damage, independent of its role in telomere length maintenance. TERT
has been suggested to act as a chromatin modulator and participate in the transcriptional regulation of
gene expression. TERT has also been reported to regulate transcript levels through an RNA-dependent
RNA Polymerase (RdRP) activity and produce siRNAs in a Dicer-dependent manner. At the mitochondria,
TERT is suggested to protect against oxidative stress-induced mtDNA damage and promote mitochondrial
integrity. These extra-telomeric functions of TERT may be advantageous in the context of increased
proliferation and metabolic stress often found in rapidly-dividing cancer cells. Understanding
the spectrum of non-canonical functions of telomerase may have important implications for the rational
design of anti-cancer chemotherapeutic drugs.
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Affiliation(s)
- Connor A.H. Thompson
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, V6T 1Z3, Canada
| | - Judy M.Y. Wong
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, V6T 1Z3, Canada
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16
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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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17
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Aschacher T, Wolf B, Aschacher O, Enzmann F, Laszlo V, Messner B, Türkcan A, Weis S, Spiegl-Kreinecker S, Holzmann K, Laufer G, Ehrlich M, Bergmann M. Long interspersed element-1 ribonucleoprotein particles protect telomeric ends in alternative lengthening of telomeres dependent cells. Neoplasia 2019; 22:61-75. [PMID: 31846834 PMCID: PMC6920197 DOI: 10.1016/j.neo.2019.11.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 11/13/2019] [Accepted: 11/14/2019] [Indexed: 12/21/2022] Open
Abstract
Malignant cells ensure telomere maintenance by the alternative lengthening of telomeres (ALT) in the absence of telomerase activity (TA). The retrotransposons "long interspersed nuclear element-1" (LINE-1, L1) are expressed in malignant cells and are primarily known to contribute to complex karyotypes. Here we demonstrate that LINE-1 ribonucleoprotein particles (L1-RNPs) expression is significantly higher in ALT+- versus in TA+-human glioma. Analyzing a role of L1-RNP in ALT, we show that L1-RNPs bind to telomeric repeat containing RNA (TERRA), which is critical for telomere stabilization and which is overexpressed in ALT+ cells. In turn, L1-RNP knockdown (KD) abrogated the nuclear retention of TERRA, resulted in increased telomeric DNA damage, decreased cell growth and reduced expression of ALT characteristics such as c-circles and PML-bodies. L1-RNP KD also decreased the expression of Shelterin- and the ALT-regulating protein Topoisomerase IIIα (TopoIIIα) indicating a more general role of L1-RNPs in supporting telomeric integrity in ALT. Our findings suggest an impact of L1-RNP on telomere stability in ALT+ dependent tumor cells. As L1-RNPs are rarely expressed in normal adult human tissue those elements might serve as a novel target for tumor ablative therapy.
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Affiliation(s)
- Thomas Aschacher
- Cardiac Surgery Research Laboratory, Department of Surgery, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna, Austria
| | - Brigitte Wolf
- Surgical Research Laboratories, Department of Surgery, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna, Austria
| | - Olivia Aschacher
- Department of Plastic and Reconstructive Surgery, Department of Surgery, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna, Austria
| | - Florian Enzmann
- Department of Vascular and Endovascular Surgery, Paracelsus Medical University Salzburg, Muellner Hauptstraße 48, 5020 Salzburg, Austria
| | - Viktoria Laszlo
- Surgical Research Laboratories, Department of Surgery, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna, Austria
| | - Barbara Messner
- Cardiac Surgery Research Laboratory, Department of Surgery, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna, Austria
| | - Adrian Türkcan
- Surgical Research Laboratories, Department of Surgery, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna, Austria
| | - Serge Weis
- Division of Neuropathology, Neuromed Campus, Kepler University Hospital, 4020 Linz, Austria
| | - Sabine Spiegl-Kreinecker
- University Clinic for Neurosurgery, Neuromed Campus, Kepler University Hospital, Johannes Kepler University, Linz, Austria
| | - Klaus Holzmann
- Department of Cancer Research, Borschkegasse 8a, 1090 Vienna, Austria; Comprehensive Cancer Centre, Medical University of Vienna, Austria
| | - Günther Laufer
- Cardiac Surgery Research Laboratory, Department of Surgery, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna, Austria
| | - Marek Ehrlich
- Cardiac Surgery Research Laboratory, Department of Surgery, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna, Austria
| | - Michael Bergmann
- Surgical Research Laboratories, Department of Surgery, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna, Austria; Comprehensive Cancer Centre, Medical University of Vienna, Austria.
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18
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Graham MK, Kim J, Da J, Brosnan-Cashman JA, Rizzo A, Baena Del Valle JA, Chia L, Rubenstein M, Davis C, Zheng Q, Cope L, Considine M, Haffner MC, De Marzo AM, Meeker AK, Heaphy CM. Functional Loss of ATRX and TERC Activates Alternative Lengthening of Telomeres (ALT) in LAPC4 Prostate Cancer Cells. Mol Cancer Res 2019; 17:2480-2491. [PMID: 31611308 DOI: 10.1158/1541-7786.mcr-19-0654] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 09/06/2019] [Accepted: 10/07/2019] [Indexed: 01/06/2023]
Abstract
A key hallmark of cancer, unlimited replication, requires cancer cells to evade both replicative senescence and potentially lethal chromosomal instability induced by telomere dysfunction. The majority of cancers overcome these critical barriers by upregulating telomerase, a telomere-specific reverse transcriptase. However, a subset of cancers maintains telomere lengths by the telomerase-independent Alternative Lengthening of Telomeres (ALT) pathway. The presence of ALT is strongly associated with recurrent cancer-specific somatic inactivating mutations in the ATRX-DAXX chromatin-remodeling complex. Here, we generate an ALT-positive adenocarcinoma cell line following functional inactivation of ATRX and telomerase in a telomerase-positive adenocarcinoma cell line. Inactivating mutations in ATRX were introduced using CRISPR-cas9 nickase into two prostate cancer cell lines, LAPC-4 (derived from a lymph node metastasis) and CWR22Rv1 (sourced from a xenograft established from a primary prostate cancer). In LAPC-4, but not CWR22Rv1, abolishing ATRX was sufficient to induce multiple ALT-associated hallmarks, including the presence of ALT-associated promyelocytic leukemia bodies (APB), extrachromosomal telomere C-circles, and dramatic telomere length heterogeneity. However, telomerase activity was still present in these ATRXKO cells. Telomerase activity was subsequently crippled in these LAPC-4 ATRXKO cells by introducing mutations in the TERC locus, the essential RNA component of telomerase. These LAPC-4 ATRXKO TERCmut cells continued to proliferate long-term and retained ALT-associated hallmarks, thereby demonstrating their reliance on the ALT mechanism for telomere maintenance. IMPLICATIONS: These prostate cancer cell line models provide a unique system to explore the distinct molecular alterations that occur upon induction of ALT, and may be useful tools to screen for ALT-specific therapies.
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Affiliation(s)
- Mindy K Graham
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Jiyoung Kim
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Joseph Da
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | | | - Anthony Rizzo
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | | | - Lionel Chia
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Michael Rubenstein
- Department of Biological Sciences, University of Maryland Baltimore County, Baltimore, Maryland
| | - Christine Davis
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Qizhi Zheng
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Leslie Cope
- Department of Oncology Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Michael Considine
- Department of Oncology Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Michael C Haffner
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Angelo M De Marzo
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland.,Department of Oncology Johns Hopkins University School of Medicine, Baltimore, Maryland.,Department of Urology, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Alan K Meeker
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland.,Department of Oncology Johns Hopkins University School of Medicine, Baltimore, Maryland.,Department of Urology, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Christopher M Heaphy
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland. .,Department of Oncology Johns Hopkins University School of Medicine, Baltimore, Maryland
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19
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Shastri S, Chatterjee B, Thakur SS. Achievements in Cancer Research and its Therapeutics in Hundred Years. Curr Top Med Chem 2019; 19:1545-1562. [PMID: 31362690 DOI: 10.2174/1568026619666190730093034] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Revised: 07/16/2019] [Accepted: 07/18/2019] [Indexed: 12/19/2022]
Abstract
Cancer research has progressed leaps and bounds over the years. This review is a brief overview of the cancer research, milestone achievements and therapeutic studies on it over the one hundred ten years which would give us an insight into how far we have come to understand and combat this fatal disease leading to millions of deaths worldwide. Modern biology has proved that cancer is a very complex disease as still we do not know precisely how it triggers. It involves several factors such as protooncogene, oncogene, kinase, tumor suppressor gene, growth factor, signalling cascade, micro RNA, immunity, environmental factors and carcinogens. However, modern technology now helps the cancer patient on the basis of acquired and established knowledge in the last hundred years to save human lives.
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Affiliation(s)
- Sravanthi Shastri
- Proteomics and Cell Signaling, Centre for Cellular and Molecular Biology, Hyderabad, India
| | - Bhaswati Chatterjee
- National Institute of Pharmaceutical Education and Research, Hyderabad, India
| | - Suman S Thakur
- Proteomics and Cell Signaling, Centre for Cellular and Molecular Biology, Hyderabad, India
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20
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Robinson NJ, Taylor DJ, Schiemann WP. Stem cells, immortality, and the evolution of metastatic properties in breast cancer: telomere maintenance mechanisms and metastatic evolution. JOURNAL OF CANCER METASTASIS AND TREATMENT 2019; 5:39. [PMID: 31440584 PMCID: PMC6706062 DOI: 10.20517/2394-4722.2019.15] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Breast cancer is the most significant cause of cancer-related death in women around the world. The vast majority of breast cancer-associated mortality stems from metastasis, which remains an incurable disease state. Metastasis results from evolution of clones that possess the insidious properties required for dissemination and colonization of distant organs. These clonal populations are descended from breast cancer stem cells (CSCs), which are also responsible for their prolonged maintenance and continued evolution. Telomeres impose a lifespan on cells that can be extended when they are actively elongated, as occurs in CSCs. Thus, changes in telomere structure serve to promote the survival of CSCs and subsequent metastatic evolution. The selection of telomere maintenance mechanism (TMM) has important consequences not only for CSC survival and evolution, but also for their coordination of various signaling pathways that choreograph the metastatic cascade. Targeting the telomere maintenance machinery may therefore provide a boon to the treatment of metastatic breast cancer. Here we review the two major TMMs and the roles they play in the development of stem and metastatic breast cancer cells. We also highlight current and future approaches to targeting these mechanisms in clinical settings to alleviate metastatic breast cancers.
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Affiliation(s)
- Nathaniel J. Robinson
- Department of Pathology, Case Western Reserve University
School of Medicine, Cleveland, OH 44106, USA
| | - Derek J. Taylor
- Department of Pharmacology, Case Western Reserve University
School of Medicine, Cleveland, OH 44106, USA
| | - William P. Schiemann
- Case Comprehensive Cancer Center, Case Western Reserve
University, Cleveland, OH 44106 USA
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21
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Romaniuk A, Paszel-Jaworska A, Totoń E, Lisiak N, Hołysz H, Królak A, Grodecka-Gazdecka S, Rubiś B. The non-canonical functions of telomerase: to turn off or not to turn off. Mol Biol Rep 2018; 46:1401-1411. [PMID: 30448892 DOI: 10.1007/s11033-018-4496-x] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Accepted: 11/12/2018] [Indexed: 12/19/2022]
Abstract
Telomerase is perceived as an immortality enzyme that enables passing the Hayflick limit. Its main function is telomere restoration but only in a limited group of cells, including cancer cells. Since it is found in a vast majority of cancer cells, it became a natural target for cancer therapy. However, it has much more functions than just altering the metabolism of telomeres-it also reveals numerous so-called non-canonical functions. Thus, a question arises whether it is always beneficial to turn it off when planning a cancer strategy and considering potential side effects? The purpose of this review is to discuss some of the recent discoveries about telomere-independent functions of telomerase in the context of cancer therapy and potential side effects.
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Affiliation(s)
- Aleksandra Romaniuk
- Department of Clinical Chemistry and Molecular Diagnostics, Poznan University of Medical Sciences, 49 Przybyszewskiego St., 60-355, Poznań, Poland
| | - Anna Paszel-Jaworska
- Department of Clinical Chemistry and Molecular Diagnostics, Poznan University of Medical Sciences, 49 Przybyszewskiego St., 60-355, Poznań, Poland
| | - Ewa Totoń
- Department of Clinical Chemistry and Molecular Diagnostics, Poznan University of Medical Sciences, 49 Przybyszewskiego St., 60-355, Poznań, Poland
| | - Natalia Lisiak
- Department of Clinical Chemistry and Molecular Diagnostics, Poznan University of Medical Sciences, 49 Przybyszewskiego St., 60-355, Poznań, Poland
| | - Hanna Hołysz
- Department of Clinical Chemistry and Molecular Diagnostics, Poznan University of Medical Sciences, 49 Przybyszewskiego St., 60-355, Poznań, Poland
| | - Anna Królak
- Department of Clinical Chemistry and Molecular Diagnostics, Poznan University of Medical Sciences, 49 Przybyszewskiego St., 60-355, Poznań, Poland
| | | | - Błażej Rubiś
- Department of Clinical Chemistry and Molecular Diagnostics, Poznan University of Medical Sciences, 49 Przybyszewskiego St., 60-355, Poznań, Poland.
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22
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Jeitany M, Bakhos-Douaihy D, Silvestre DC, Pineda JR, Ugolin N, Moussa A, Gauthier LR, Busso D, Junier MP, Chneiweiss H, Chevillard S, Desmaze C, Boussin FD. Opposite effects of GCN5 and PCAF knockdowns on the alternative mechanism of telomere maintenance. Oncotarget 2018; 8:26269-26280. [PMID: 28412741 PMCID: PMC5432255 DOI: 10.18632/oncotarget.15447] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Accepted: 02/06/2017] [Indexed: 12/22/2022] Open
Abstract
Cancer cells can use a telomerase-independent mechanism, known as alternative lengthening of telomeres (ALT), to elongate their telomeres. General control non-derepressible 5 (GCN5) and P300/CBP-associated factor (PCAF) are two homologous acetyltransferases that are mutually exclusive subunits in SAGA-like complexes. Here, we reveal that down regulation of GCN5 and PCAF had differential effects on some phenotypic characteristics of ALT cells. Our results suggest that GCN5 is present at telomeres and opposes telomere recombination, in contrast to PCAF that may indirectly favour them in ALT cells.
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Affiliation(s)
- Maya Jeitany
- Laboratoire de Radiopathologie, CEA, Institut de Radiobiologie Cellulaire et Moléculaire, Fontenay-aux-Roses, France.,INSERM UMR967, Fontenay-aux-Roses, France.,Université Paris VII, UMR967, Fontenay-aux-Roses, France.,Université Paris XI, UMR967, Fontenay-aux-Roses, France
| | - Dalal Bakhos-Douaihy
- Laboratoire de Radiopathologie, CEA, Institut de Radiobiologie Cellulaire et Moléculaire, Fontenay-aux-Roses, France.,INSERM UMR967, Fontenay-aux-Roses, France.,Université Paris VII, UMR967, Fontenay-aux-Roses, France.,Université Paris XI, UMR967, Fontenay-aux-Roses, France
| | - David C Silvestre
- Laboratoire de Radiopathologie, CEA, Institut de Radiobiologie Cellulaire et Moléculaire, Fontenay-aux-Roses, France.,INSERM UMR967, Fontenay-aux-Roses, France.,Université Paris VII, UMR967, Fontenay-aux-Roses, France.,Université Paris XI, UMR967, Fontenay-aux-Roses, France
| | - Jose R Pineda
- Laboratoire de Radiopathologie, CEA, Institut de Radiobiologie Cellulaire et Moléculaire, Fontenay-aux-Roses, France.,INSERM UMR967, Fontenay-aux-Roses, France.,Université Paris VII, UMR967, Fontenay-aux-Roses, France.,Université Paris XI, UMR967, Fontenay-aux-Roses, France
| | - Nicolas Ugolin
- Laboratoire de Cancérologie Expérimentale, iRCM, DSV, CEA, Fontenay-aux-Roses, France
| | - Angela Moussa
- Laboratoire de Radiopathologie, CEA, Institut de Radiobiologie Cellulaire et Moléculaire, Fontenay-aux-Roses, France.,INSERM UMR967, Fontenay-aux-Roses, France.,Université Paris VII, UMR967, Fontenay-aux-Roses, France.,Université Paris XI, UMR967, Fontenay-aux-Roses, France
| | - Laurent R Gauthier
- Laboratoire de Radiopathologie, CEA, Institut de Radiobiologie Cellulaire et Moléculaire, Fontenay-aux-Roses, France.,INSERM UMR967, Fontenay-aux-Roses, France.,Université Paris VII, UMR967, Fontenay-aux-Roses, France.,Université Paris XI, UMR967, Fontenay-aux-Roses, France
| | - Didier Busso
- INSERM UMR967, Fontenay-aux-Roses, France.,CIGEx, IRCM, Fontenay-aux-Roses, France
| | - Marie-Pierre Junier
- CNRS UMR8246 Neuroscience Paris Seine-IBPS, Team Glial Plasticity, Paris, France.,Inserm U1130, Neuroscience Paris Seine-IBPS, Team Glial Plasticity, Paris, France.,University Pierre and Marie Curie UMCR18, Neuroscience Paris Seine-IBPS, Team Glial Plasticity, Paris, France
| | - Hervé Chneiweiss
- CNRS UMR8246 Neuroscience Paris Seine-IBPS, Team Glial Plasticity, Paris, France.,Inserm U1130, Neuroscience Paris Seine-IBPS, Team Glial Plasticity, Paris, France.,University Pierre and Marie Curie UMCR18, Neuroscience Paris Seine-IBPS, Team Glial Plasticity, Paris, France
| | - Sylvie Chevillard
- Laboratoire de Cancérologie Expérimentale, iRCM, DSV, CEA, Fontenay-aux-Roses, France
| | - Chantal Desmaze
- Laboratoire de Radiopathologie, CEA, Institut de Radiobiologie Cellulaire et Moléculaire, Fontenay-aux-Roses, France.,INSERM UMR967, Fontenay-aux-Roses, France.,Université Paris VII, UMR967, Fontenay-aux-Roses, France.,Université Paris XI, UMR967, Fontenay-aux-Roses, France
| | - François D Boussin
- Laboratoire de Radiopathologie, CEA, Institut de Radiobiologie Cellulaire et Moléculaire, Fontenay-aux-Roses, France.,INSERM UMR967, Fontenay-aux-Roses, France.,Université Paris VII, UMR967, Fontenay-aux-Roses, France.,Université Paris XI, UMR967, Fontenay-aux-Roses, France
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23
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Integrative genomic and transcriptomic analysis of leiomyosarcoma. Nat Commun 2018; 9:144. [PMID: 29321523 PMCID: PMC5762758 DOI: 10.1038/s41467-017-02602-0] [Citation(s) in RCA: 184] [Impact Index Per Article: 30.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Accepted: 12/13/2017] [Indexed: 02/07/2023] Open
Abstract
Leiomyosarcoma (LMS) is an aggressive mesenchymal malignancy with few therapeutic options. The mechanisms underlying LMS development, including clinically actionable genetic vulnerabilities, are largely unknown. Here we show, using whole-exome and transcriptome sequencing, that LMS tumors are characterized by substantial mutational heterogeneity, near-universal inactivation of TP53 and RB1, widespread DNA copy number alterations including chromothripsis, and frequent whole-genome duplication. Furthermore, we detect alternative telomere lengthening in 78% of cases and identify recurrent alterations in telomere maintenance genes such as ATRX, RBL2, and SP100, providing insight into the genetic basis of this mechanism. Finally, most tumors display hallmarks of "BRCAness", including alterations in homologous recombination DNA repair genes, multiple structural rearrangements, and enrichment of specific mutational signatures, and cultured LMS cells are sensitive towards olaparib and cisplatin. This comprehensive study of LMS genomics has uncovered key biological features that may inform future experimental research and enable the design of novel therapies.
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24
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Lee EJ, Hwang I, Lee JY, Park JN, Kim KC, Kim GH, Kang CM, Kim I, Lee SY, Kim HS. Hepatocyte Growth Factor Improves the Therapeutic Efficacy of Human Bone Marrow Mesenchymal Stem Cells via RAD51. Mol Ther 2017; 26:845-859. [PMID: 29398486 DOI: 10.1016/j.ymthe.2017.12.015] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Revised: 11/29/2017] [Accepted: 12/14/2017] [Indexed: 02/08/2023] Open
Abstract
Human embryonic stem cell-derived mesenchymal stem cells (hE-MSCs) have greater proliferative capacity than other human mesenchymal stem cells (hMSCs), suggesting that they may have wider applications in regenerative cellular therapy. In this study, to uncover the anti-senescence mechanism in hE-MSCs, we compared hE-MSCs with adult bone marrow (hBM-MSCs) and found that hepatocyte growth factor (HGF) was more abundantly expressed in hE-MSCs than in hBM-MSCs and that it induced the transcription of RAD51 and facilitated its SUMOylation at K70. RAD51 induction/modification by HGF not only increased telomere length but also increased mtDNA replication, leading to increased ATP generation. Moreover, HGF-treated hBM-MSCs showed significantly better therapeutic efficacy than naive hBM-MSCs. Together, the data suggest that the RAD51-mediated effects of HGF prevent hMSC senescence by promoting telomere lengthening and inducing mtDNA replication and function, which opens the prospect of developing novel therapies for liver disease.
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Affiliation(s)
- Eun Ju Lee
- Biomedical Research Institute, Seoul National University Hospital, Seoul, Republic of Korea
| | - Injoo Hwang
- Molecular Medicine & Biopharmaceutical Sciences, Seoul National University, Seoul, Republic of Korea
| | - Ji Yeon Lee
- Molecular Medicine & Biopharmaceutical Sciences, Seoul National University, Seoul, Republic of Korea
| | - Jong Nam Park
- Molecular Medicine & Biopharmaceutical Sciences, Seoul National University, Seoul, Republic of Korea
| | - Keun Cheon Kim
- Molecular Medicine & Biopharmaceutical Sciences, Seoul National University, Seoul, Republic of Korea
| | - Gi-Hwan Kim
- Molecular Medicine & Biopharmaceutical Sciences, Seoul National University, Seoul, Republic of Korea
| | - Chang-Mo Kang
- Korea Institute of Radiological & Medical Sciences, Seoul, Republic of Korea
| | - Irene Kim
- Molecular Medicine & Biopharmaceutical Sciences, Seoul National University, Seoul, Republic of Korea
| | - Seo-Yeon Lee
- Biomedical Research Institute, Seoul National University Hospital, Seoul, Republic of Korea
| | - Hyo-Soo Kim
- Department of Internal Medicine, Seoul National University College of Medicine, Molecular Medicine & Biopharmaceutical Sciences, Seoul National University, Seoul, Republic of Korea.
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25
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Carneiro MC, de Castro IP, Ferreira MG. Telomeres in aging and disease: lessons from zebrafish. Dis Model Mech 2017; 9:737-48. [PMID: 27482813 PMCID: PMC4958310 DOI: 10.1242/dmm.025130] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Age is the highest risk factor for some of the most prevalent human diseases, including cancer. Telomere shortening is thought to play a central role in the aging process in humans. The link between telomeres and aging is highlighted by the fact that genetic diseases causing telomerase deficiency are associated with premature aging and increased risk of cancer. For the last two decades, this link has been mostly investigated using mice that have long telomeres. However, zebrafish has recently emerged as a powerful and complementary model system to study telomere biology. Zebrafish possess human-like short telomeres that progressively decline with age, reaching lengths in old age that are observed when telomerase is mutated. The extensive characterization of its well-conserved molecular and cellular physiology makes this vertebrate an excellent model to unravel the underlying relationship between telomere shortening, tissue regeneration, aging and disease. In this Review, we explore the advantages of using zebrafish in telomere research and discuss the primary discoveries made in this model that have contributed to expanding our knowledge of how telomere attrition contributes to cellular senescence, organ dysfunction and disease. Summary: In this Review, the authors explore the advantages of using zebrafish in telomere research and discuss the primary discoveries made in this model that have contributed to expanding our knowledge of how telomere attrition contributes to cellular senescence, organ dysfunction and disease.
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26
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Abstract
Bacteria and viruses possess circular DNA, whereas eukaryotes with typically very large DNA molecules have had to evolve into linear chromosomes to circumvent the problem of supercoiling circular DNA of that size. Consequently, such organisms possess telomeres to cap chromosome ends. Telomeres are essentially tandem repeats of any DNA sequence that are present at the ends of chromosomes. Their biology has been an enigmatic one, involving various molecules interacting dynamically in an evolutionarily well-trimmed fashion. Telomeres range from canonical hexameric repeats in most eukaryotes to unimaginably random retrotransposons, which attach to chromosome ends and reverse-transcribe to DNA in some plants and insects. Telomeres invariably associate with specialised protein complexes that envelop it, also regulating access of the ends to legitimate enzymes involved in telomere metabolism. They also transcribe into repetitive RNA which also seems to be playing significant roles in telomere maintenance. Telomeres thus form the intersection of DNA, protein, and RNA molecules acting in concert to maintain chromosome integrity. Telomere biology is emerging to appear ever more complex than previously envisaged, with the continual discovery of more molecules and interplays at the telomeres. This review also includes a section dedicated to the history of telomere biology, and intends to target the scientific audience new to the field by rendering an understanding of the phenomenon of chromosome end protection at large, with more emphasis on the biology of human telomeres. The review provides an update on the field and mentions the questions that need to be addressed.
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Affiliation(s)
- Shriram Venkatesan
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, 117597 Singapore, Singapore.
| | - Aik Kia Khaw
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, 117597 Singapore, Singapore.
- Clinical Research Unit, Khoo Teck Puat Hospital, 768828 Singapore, Singapore.
| | - Manoor Prakash Hande
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, 117597 Singapore, Singapore.
- Tembusu College, National University of Singapore, 138598 Singapore, Singapore.
- VIT University, Vellore 632014, India.
- Mangalore University, Mangalore 574199, India.
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27
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Apte MS, Cooper JP. Life and cancer without telomerase: ALT and other strategies for making sure ends (don't) meet. Crit Rev Biochem Mol Biol 2016; 52:57-73. [PMID: 27892716 DOI: 10.1080/10409238.2016.1260090] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
While most cancer cells rely on telomerase expression/re-activation for linear chromosome maintenance and sustained proliferation, a significant population of cancers (10-15%) employs telomerase-independent strategies, collectively dubbed Alternative Lengthening of Telomeres (ALT). Most ALT cells relax the usual role of telomeres as inhibitors of local homologous recombination while maintaining the ability of telomeres to prohibit local non-homologous end joining reactions. Here we review current concepts surrounding how ALT telomeres achieve this new balance via alterations in chromatin landscape, DNA damage repair processes and handling of telomeric transcription. We also discuss telomerase independent end maintenance strategies utilized by other organisms, including fruitflies and yeasts, to draw parallels and contrasts and highlight additional modes, beyond ALT, that may be available to telomerase-minus cancers. We conclude by commenting on promises and challenges in the development of effective anti-ALT cancer therapies.
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Affiliation(s)
- Manasi S Apte
- a Laboratory of Biochemistry and Molecular Biology , Center for Cancer Research, National Cancer Institute, NIH , Bethesda , MD , USA
| | - Julia Promisel Cooper
- a Laboratory of Biochemistry and Molecular Biology , Center for Cancer Research, National Cancer Institute, NIH , Bethesda , MD , USA
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28
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Druliner BR, Ruan X, Johnson R, Grill D, O'Brien D, Lai TP, Rashtak S, Felmlee-Devine D, Washechek-Aletto J, Malykh A, Smyrk T, Oberg A, Liu H, Shay JW, Ahlquist DA, Boardman LA. Time Lapse to Colorectal Cancer: Telomere Dynamics Define the Malignant Potential of Polyps. Clin Transl Gastroenterol 2016; 7:e188. [PMID: 27584834 PMCID: PMC5288594 DOI: 10.1038/ctg.2016.48] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Accepted: 07/26/2016] [Indexed: 02/07/2023] Open
Abstract
Objective: Whereas few adenomas become cancer, most colorectal cancers arise from adenomas. Telomere length is a recognized biomarker in multiple cancers, and telomere maintenance mechanisms (TMM) are exploited by malignant cells. We sought to determine whether telomere length and TMM distinguish cancer-associated adenomas from those that are cancer-free. Methods: Tissues were identified as cancer-adjacent polyp (CAP)—residual adenoma contiguous with cancer—and cancer-free polyp (CFP)—adenomas without malignancy. Telomere length, TMM, and expression were measured in 102 tissues including peripheral blood leukocytes (PBLs), normal colon epithelium, adenoma, and cancer (in CAP cases) from 31 patients. Telomere length was measured in a separate cohort of 342 PBL from CAP and CFP patients. Results: The mean differences in telomere length between normal and adenoma were greater in CAP than in CFP cases, P=0.001; telomere length in PBL was 91.7 bp greater in CAP than in CFP, P=0.007. Each 100 bp telomere increase was associated with a 1.14 (1.04–1.26) increased odds of being a CAP, P=0.0063. The polyp tissue from CAP patients had shorter telomeres and higher Telomerase reverse transcriptase (hTERT) expression compared with polyps from CFP patients, P=0.05. There was a greater degree of alternative lengthening of telomere (ALT) level difference in CFP polyps than in CAP polyps. The polyp telomere lengths of aggressive CAPs were significantly different from the polyps of non-aggressive CAPs, P=0.01. Conclusions: Adenomas that progress to cancer exhibit distinct telomere length and TMM profiles. We report for the first time that PBL telomeres differ in patients with polyps that become malignant, and therefore may have clinical value in adenoma risk assessment and management.
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Affiliation(s)
- Brooke R Druliner
- Department of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota, USA
| | - Xiaoyang Ruan
- Biomedical Statistics and Informatics, Mayo Clinic, Rochester, Minnesota, USA
| | - Ruth Johnson
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota, USA
| | - Diane Grill
- Biomedical Statistics and Informatics, Mayo Clinic, Rochester, Minnesota, USA
| | - Daniel O'Brien
- Biomedical Statistics and Informatics, Mayo Clinic, Rochester, Minnesota, USA
| | - Tsung-Po Lai
- Department of Cell Biology UT Southwestern Medical Center, Dallas, Texas, USA
| | - Shahrooz Rashtak
- Department of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota, USA
| | - Donna Felmlee-Devine
- Department of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota, USA
| | - Jill Washechek-Aletto
- Department of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota, USA
| | - Andrei Malykh
- Capital Biosciences Inc., Gaithersburg, Maryland, USA
| | - Thomas Smyrk
- Anatomic Pathology, Mayo Clinic, Rochester, Minnesota, USA
| | - Ann Oberg
- Biomedical Statistics and Informatics, Mayo Clinic, Rochester, Minnesota, USA
| | - Hongfang Liu
- Biomedical Statistics and Informatics, Mayo Clinic, Rochester, Minnesota, USA
| | - Jerry W Shay
- Department of Cell Biology UT Southwestern Medical Center, Dallas, Texas, USA
| | - David A Ahlquist
- Department of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota, USA
| | - Lisa A Boardman
- Department of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota, USA
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29
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Abstract
The unlimited proliferation of cancer cells requires a mechanism to prevent telomere shortening. Alternative Lengthening of Telomeres (ALT) is an homologous recombination-mediated mechanism of telomere elongation used in tumors, including osteosarcomas, soft tissue sarcoma subtypes, and glial brain tumors. Mutations in the ATRX/DAXX chromatin remodeling complex have been reported in tumors and cell lines that use the ALT mechanism, suggesting that ATRX may be an ALT repressor. We show here that knockout or knockdown of ATRX in mortal cells or immortal telomerase-positive cells is insufficient to activate ALT. Notably, however, in SV40-transformed mortal fibroblasts ATRX loss results in either a significant increase in the proportion of cell lines activating ALT (instead of telomerase) or in a significant decrease in the time prior to ALT activation. These data indicate that loss of ATRX function cooperates with one or more as-yet unidentified genetic or epigenetic alterations to activate ALT. Moreover, transient ATRX expression in ALT-positive/ATRX-negative cells represses ALT activity. These data provide the first direct, functional evidence that ATRX represses ALT.
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30
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Saalfrank A, Janssen KP, Ravon M, Flisikowski K, Eser S, Steiger K, Flisikowska T, Müller-Fliedner P, Schulze É, Brönner C, Gnann A, Kappe E, Böhm B, Schade B, Certa U, Saur D, Esposito I, Kind A, Schnieke A. A porcine model of osteosarcoma. Oncogenesis 2016; 5:e210. [PMID: 26974205 PMCID: PMC4815050 DOI: 10.1038/oncsis.2016.19] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Revised: 01/25/2016] [Accepted: 01/28/2016] [Indexed: 12/15/2022] Open
Abstract
We previously produced pigs with a latent oncogenic TP53 mutation. Humans with TP53 germline mutations are predisposed to a wide spectrum of early-onset cancers, predominantly breast, brain, adrenal gland cancer, soft tissue sarcomas and osteosarcomas. Loss of p53 function has been observed in >50% of human cancers. Here we demonstrate that porcine mesenchymal stem cells (MSCs) convert to a transformed phenotype after activation of latent oncogenic TP53R167H and KRASG12D, and overexpression of MYC promotes tumorigenesis. The process mimics key molecular aspects of human sarcomagenesis. Transformed porcine MSCs exhibit genomic instability, with complex karyotypes, and develop into sarcomas on transplantation into immune-deficient mice. In pigs, heterozygous knockout of TP53 was sufficient for spontaneous osteosarcoma development in older animals, whereas homozygous TP53 knockout resulted in multiple large osteosarcomas in 7–8-month-old animals. This is the first report that engineered mutation of an endogenous tumour-suppressor gene leads to invasive cancer in pigs. Unlike in Trp53 mutant mice, osteosarcoma developed in the long bones and skull, closely recapitulating the human disease. These animals thus promise a model for juvenile osteosarcoma, a relatively uncommon but devastating disease.
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Affiliation(s)
- A Saalfrank
- Chair of Livestock Biotechnology, Technische Universität München, Freising, Germany
| | - K-P Janssen
- Department of Surgery, Klinikum Rechts der Isar, Technische Universität München, Munich, Germany
| | - M Ravon
- Roche Pharma Research and Early Development, Pharmaceutical Sciences, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd., Basel, Switzerland
| | - K Flisikowski
- Chair of Livestock Biotechnology, Technische Universität München, Freising, Germany
| | - S Eser
- Department of Medicine II, Klinikum Rechts der Isar, Technische Universität München, Munich, Germany
| | - K Steiger
- Department of Pathology, Klinikum Rechts der Isar, Technische Universität München, Munich, Germany
| | - T Flisikowska
- Chair of Livestock Biotechnology, Technische Universität München, Freising, Germany
| | - P Müller-Fliedner
- Chair of Livestock Biotechnology, Technische Universität München, Freising, Germany
| | - É Schulze
- Chair of Livestock Biotechnology, Technische Universität München, Freising, Germany
| | - C Brönner
- Chair of Livestock Biotechnology, Technische Universität München, Freising, Germany
| | - A Gnann
- Department of Surgery, Klinikum Rechts der Isar, Technische Universität München, Munich, Germany
| | - E Kappe
- Department of Pathology, Bavarian Animal Health Service, Poing, Germany
| | - B Böhm
- Department of Pathology, Bavarian Animal Health Service, Poing, Germany
| | - B Schade
- Department of Pathology, Bavarian Animal Health Service, Poing, Germany
| | - U Certa
- Roche Pharma Research and Early Development, Pharmaceutical Sciences, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd., Basel, Switzerland
| | - D Saur
- Department of Medicine II, Klinikum Rechts der Isar, Technische Universität München, Munich, Germany
| | - I Esposito
- Institute of Pathology, Heinrich-Heine-University of Düsseldorf, Düsseldorf, Germany
| | - A Kind
- Chair of Livestock Biotechnology, Technische Universität München, Freising, Germany
| | - A Schnieke
- Chair of Livestock Biotechnology, Technische Universität München, Freising, Germany
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31
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Decreased proliferation ability and differentiation potential of mesenchymal stem cells of osteoporosis rat. ASIAN PAC J TROP MED 2014; 7:358-63. [DOI: 10.1016/s1995-7645(14)60055-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Revised: 01/15/2014] [Accepted: 03/15/2014] [Indexed: 11/23/2022] Open
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32
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Mathematical model of a telomerase transcriptional regulatory network developed by cell-based screening: analysis of inhibitor effects and telomerase expression mechanisms. PLoS Comput Biol 2014; 10:e1003448. [PMID: 24550717 PMCID: PMC3923661 DOI: 10.1371/journal.pcbi.1003448] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2013] [Accepted: 11/30/2013] [Indexed: 12/16/2022] Open
Abstract
Cancer cells depend on transcription of telomerase reverse transcriptase (TERT). Many transcription factors affect TERT, though regulation occurs in context of a broader network. Network effects on telomerase regulation have not been investigated, though deeper understanding of TERT transcription requires a systems view. However, control over individual interactions in complex networks is not easily achievable. Mathematical modelling provides an attractive approach for analysis of complex systems and some models may prove useful in systems pharmacology approaches to drug discovery. In this report, we used transfection screening to test interactions among 14 TERT regulatory transcription factors and their respective promoters in ovarian cancer cells. The results were used to generate a network model of TERT transcription and to implement a dynamic Boolean model whose steady states were analysed. Modelled effects of signal transduction inhibitors successfully predicted TERT repression by Src-family inhibitor SU6656 and lack of repression by ERK inhibitor FR180204, results confirmed by RT-QPCR analysis of endogenous TERT expression in treated cells. Modelled effects of GSK3 inhibitor 6-bromoindirubin-3′-oxime (BIO) predicted unstable TERT repression dependent on noise and expression of JUN, corresponding with observations from a previous study. MYC expression is critical in TERT activation in the model, consistent with its well known function in endogenous TERT regulation. Loss of MYC caused complete TERT suppression in our model, substantially rescued only by co-suppression of AR. Interestingly expression was easily rescued under modelled Ets-factor gain of function, as occurs in TERT promoter mutation. RNAi targeting AR, JUN, MXD1, SP3, or TP53, showed that AR suppression does rescue endogenous TERT expression following MYC knockdown in these cells and SP3 or TP53 siRNA also cause partial recovery. The model therefore successfully predicted several aspects of TERT regulation including previously unknown mechanisms. An extrapolation suggests that a dominant stimulatory system may programme TERT for transcriptional stability. Tumour cells acquire the ability to divide and multiply indefinitely whereas normal cells can undergo only a limited number of divisions. The switch to immortalisation of the tumour cell is dependent on maintaining the integrity of telomere DNA which forms chromosome ends and is achieved through activation of the telomerase enzyme by turning on synthesis of the TERT gene, which is usually silenced in normal cells. Suppressing telomerase is toxic to cancer cells and it is widely believed that understanding TERT regulation could lead to potential cancer therapies. Previous studies have identified many of the factors which individually contribute to activate or repress TERT levels in cancer cells. However, transcription factors do not behave in isolation in cells, but rather as a complex co-operative network displaying inter-regulation. Therefore, full understanding of TERT regulation will require a broader view of the transcriptional network. In this paper we take a computational modelling approach to study TERT regulation at the network level. We tested interactions between 14 TERT-regulatory factors in an ovarian cancer cell line using a screening approach and developed a model to analyse which network interventions were able to silence TERT.
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33
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Gocha ARS, Harris J, Groden J. Alternative mechanisms of telomere lengthening: permissive mutations, DNA repair proteins and tumorigenic progression. Mutat Res 2012; 743-744:142-150. [PMID: 23219603 DOI: 10.1016/j.mrfmmm.2012.11.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2012] [Revised: 11/22/2012] [Accepted: 11/24/2012] [Indexed: 01/05/2023]
Abstract
Telomeres protect chromosome termini to maintain genomic stability and regulate cellular lifespan. Maintenance of telomere length is required for neoplastic cells after the acquisition of mutations that deregulate cell cycle control and increase cellular proliferation, and can occur through expression of the enzyme telomerase or in a telomerase-independent manner termed alternative lengthening of telomeres (ALT). The precise mechanisms that govern the activation of ALT or telomerase in tumor cells are unknown, although cellular origin may favor one or the other mechanisms. ALT pathways are incompletely understood to date; however, recent publications have increasingly broadened our understanding of how ALT is activated, how it proceeds, and how it influences tumor growth. Specific mutational events influence ALT activation, as mutations in genes that suppress recombination and/or alterations in the regulation of telomerase expression are associated with ALT. Once engaged, ALT uses DNA repair proteins to maintain telomeres in the absence of telomerase; experiments that manipulate the expression of specific proteins in cells using ALT are illuminating some of its mechanisms. Furthermore, ALT may influence tumor growth, as experimental and clinical data suggest that telomerase expression may favor tumor progression. This review summarizes recent findings in mammalian cells and models, as well as clinical data, that identify the genetic mutations permissive to ALT, the DNA repair proteins involved in ALT mechanisms and the importance of telomere maintenance mechanisms for tumor progression. A comprehensive understanding of the mechanisms that permit tumor cell immortalization will be important for identifying novel therapeutic targets in cancer.
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Affiliation(s)
- April Renee Sandy Gocha
- Department of Molecular Virology, Immunology and Medical Genetics, The Ohio State University College of Medicine, Columbus, OH 43210, United States
| | - Julia Harris
- Department of Molecular Virology, Immunology and Medical Genetics, The Ohio State University College of Medicine, Columbus, OH 43210, United States
| | - Joanna Groden
- Department of Molecular Virology, Immunology and Medical Genetics, The Ohio State University College of Medicine, Columbus, OH 43210, United States.
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34
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Tilman G, Arnoult N, Lenglez S, Van Beneden A, Loriot A, De Smet C, Decottignies A. Cancer-linked satellite 2 DNA hypomethylation does not regulate Sat2 non-coding RNA expression and is initiated by heat shock pathway activation. Epigenetics 2012; 7:903-13. [PMID: 22722874 DOI: 10.4161/epi.21107] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Epigenetic dysfunctions, including DNA methylation alterations, play major roles in cancer initiation and progression. Although it is well established that gene promoter demethylation activates transcription, it remains unclear whether hypomethylation of repetitive heterochromatin similarly affects expression of non-coding RNA from these loci. Understanding how repetitive non-coding RNAs are transcriptionally regulated is important given that their established upregulation by the heat shock (HS) pathway suggests important functions in cellular response to stress, possibly by promoting heterochromatin reconstruction. We found that, although pericentromeric satellite 2 (Sat2) DNA hypomethylation is detected in a majority of cancer cell lines of various origins, DNA methylation loss does not constitutively hyperactivate Sat2 expression, and also does not facilitate Sat2 transcriptional induction upon heat shock. In melanoma tumor samples, our analysis revealed that the HS response, frequently upregulated in tumors, is probably the main determinant of Sat2 RNA expression in vivo. Next, we tested whether HS pathway hyperactivation may drive Sat2 demethylation. Strikingly, we found that both hyperthermia and hyperactivated RasV12 oncogene, another potent inducer of the HS pathway, reduced Sat2 methylation levels by up to 27% in human fibroblasts recovering from stress. Demethylation occurred locally on Sat2 repeats, resulting in a demethylation signature that was also detected in cancer cell lines with moderate genome-wide hypomethylation. We therefore propose that upregulation of Sat2 transcription in response to HS pathway hyperactivation during tumorigenesis may promote localized demethylation of the locus. This, in turn, may contribute to tumorigenesis, as demethylation of Sat2 was previously reported to favor chromosomal rearrangements.
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Affiliation(s)
- Gaëlle Tilman
- Genetic and Epigenetic Alterations of Genomes Research Group, de Duve Institute, Catholic University of Louvain, Brussels, Belgium
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35
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Abstract
Soft tissue sarcomas are an uncommon and diverse group of more than 50 mesenchymal malignancies. The pathogenesis of many of these is poorly understood, but others have begun to reveal the secrets of their underlying mechanisms. With considerable effort over recent years, soft tissue sarcomas have increasingly been classified on the basis of underlying molecular alterations. In turn, this has allowed the development and application of targeted agents in several specific, molecularly defined, sarcoma subtypes. This review will focus on the rationale for targeted therapy in sarcoma, with emphasis on the relevance of specific molecular factors and pathways in both translocation-associated sarcomas and in genetically complex tumors. In addition, we will address some of the early successes in sarcoma-targeted therapy as well as a few challenges and disappointments in this field. Finally, we will discuss several possible opportunities represented by poorly understood, but potentially promising new therapeutic targets, as well as several novel biological agents currently in preclinical and early phase I/II trials. This will provide the reader with the context for understanding the current state of this field and a sense of where it may be headed in the coming years.
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Affiliation(s)
- Elizabeth G Demicco
- Department of Pathology, The University of Texas M.D. Anderson Cancer Center, Houston, 77030-4009, USA
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36
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Venturini L, Daidone MG, Motta R, Cimino-Reale G, Hoare SF, Gronchi A, Folini M, Keith WN, Zaffaroni N. Telomere maintenance mechanisms in malignant peripheral nerve sheath tumors: expression and prognostic relevance. Neuro Oncol 2012; 14:736-44. [PMID: 22516689 DOI: 10.1093/neuonc/nos083] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
This study investigated the prevalence and the prognostic relevance of the 2 known telomere maintenance mechanisms (TMMs), telomerase activity (TA) and alternative lengthening of telomeres (ALT), in malignant peripheral nerve sheath tumors (MPNST). In 57 specimens from 49 patients with MPNST (35 sporadic, 14 neurofibromatosis type 1-related), TA was determined using the telomeric repeat amplification protocol, and ALT was detected by assaying ALT-associated promyelocytic leukemia bodies (APB) and terminal restriction fragment (TRF) length distribution. TA or ALT (defined on the basis of APB) alone was found in 24.6% or 26.3% of the lesions, respectively, whereas 6 cases (10.5%) were TA+/ALT+. A concordance between APB and TRF results in defining the ALT status was observed in 44 of 57 cases (77.2%; P < .0001). TA was more frequently expressed in samples from patients with neurofibromatosis type 1 than in those with sporadic disease (60% vs 29.4%, P = 0.087). In the overall series, TA proved to be prognostic for 5-year disease-specific death (hazard ratio, 3.78; 95% confidence interval [CI], 1.60-8.95; P = .002), even when adjusted for the presence of neurofibromatosis type 1 (hazard ratio, 4.22; 95% CI, 1.804-9.874; P = .001) and margin status after surgery (hazard ratio, 5.78; 95% CI, 2.19-15.26; P < .001). Conversely, ALT did not significantly affect clinical outcome of MPNST using either APB expression (hazard ratio, 1.25; 95% CI 0.54-2.89; P = 0.605) or TRF distribution (hazard ratio, 0.57; 95% CI, 0.17-1.96; P = .375) as the detection approach. Our results indicate for the first time that both TMMs, TA and ALT, are present in MPNST and differentially affect patient prognosis.
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Affiliation(s)
- Lorenza Venturini
- Department of Experimental Oncology and Molecular Medicine, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy
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Antitelomerase therapy provokes ALT and mitochondrial adaptive mechanisms in cancer. Cell 2012; 148:651-63. [PMID: 22341440 DOI: 10.1016/j.cell.2011.12.028] [Citation(s) in RCA: 216] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2011] [Revised: 11/08/2011] [Accepted: 12/30/2011] [Indexed: 11/21/2022]
Abstract
To assess telomerase as a cancer therapeutic target and determine adaptive mechanisms to telomerase inhibition, we modeled telomerase reactivation and subsequent extinction in T cell lymphomas arising in Atm(-/-) mice engineered with an inducible telomerase reverse transcriptase allele. Telomerase reactivation in the setting of telomere dysfunction enabled full malignant progression with alleviation of telomere dysfunction-induced checkpoints. These cancers possessed copy number alterations targeting key loci in human T cell lymphomagenesis. Upon telomerase extinction, tumor growth eventually slowed with reinstatement of telomere dysfunction-induced checkpoints, yet growth subsequently resumed as tumors acquired alternative lengthening of telomeres (ALT) and aberrant transcriptional networks centering on mitochondrial biology and oxidative defense. ALT+ tumors acquired amplification/overexpression of PGC-1β, a master regulator of mitochondrial biogenesis and function, and they showed marked sensitivity to PGC-1β or SOD2 knockdown. Genetic modeling of telomerase extinction reveals vulnerabilities that motivate coincidental inhibition of mitochondrial maintenance and oxidative defense mechanisms to enhance antitelomerase cancer therapy.
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Durant ST. Telomerase-independent paths to immortality in predictable cancer subtypes. J Cancer 2012; 3:67-82. [PMID: 22315652 PMCID: PMC3273709 DOI: 10.7150/jca.3965] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2011] [Accepted: 01/28/2012] [Indexed: 01/17/2023] Open
Abstract
The vast majority of cancers commandeer the activity of telomerase - the remarkable enzyme responsible for prolonging cellular lifespan by maintaining the length of telomeres at the ends of chromosomes. Telomerase is only normally active in embryonic and highly proliferative somatic cells. Thus, targeting telomerase is an attractive anti-cancer therapeutic rationale currently under investigation in various phases of clinical development. However, previous reports suggest that an average of 10-15% of all cancers lose the functional activity of telomerase and most of these turn to an Alternative Lengthening of Telomeres pathway (ALT). ALT-positive tumours will therefore not respond to anti-telomerase therapies and there is a real possibility that such drugs would be toxic to normal telomerase-utilising cells and ultimately select for resistant cells that activate an ALT mechanism. ALT exploits certain DNA damage response (DDR) components to counteract telomere shortening and rapid trimming. ALT has been reported in many cancer subtypes including sarcoma, gastric carcinoma, central nervous system malignancies, subtypes of kidney (Wilm's Tumour) and bladder carcinoma, mesothelioma, malignant melanoma and germ cell testicular cancers to name but a few. A recent heroic study that analysed ALT in over six thousand tumour samples supports this historical spread, although only reporting an approximate 4% prevalence. This review highlights the various methods of ALT detection, unravels several molecular ALT models thought to promote telomere maintenance and elongation, spotlights the DDR components known to facilitate these and explores why certain tissues are more likely to subvert DDR away from its usually protective functions, resulting in a predictive pattern of prevalence in specific cancer subsets.
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Affiliation(s)
- Stephen T Durant
- AstraZeneca - DNA Damage Response, Bioscience, Oncology iMed, Alderley Park, Cheshire, SK10 4TG, England, UK
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Keith WN, Lafferty-Whyte K, Cairney CJ, Zaffaroni N, Bilsland A. Response to ‘Validating a gene expression signature proposed to differentiate liposarcomas that use different telomere maintenance mechanisms’. Oncogene 2012. [DOI: 10.1038/onc.2011.374] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Doyle KR, Mitchell MA, Roberts CL, James S, Johnson JE, Zhou Y, von Mehren M, Lev D, Kipling D, Broccoli D. Validating a gene expression signature proposed to differentiate liposarcomas that use different telomere maintenance mechanisms. Oncogene 2012; 31:265-6; author reply 267-8. [PMID: 21706060 PMCID: PMC3602663 DOI: 10.1038/onc.2011.225] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
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Taylor BS, Barretina J, Maki RG, Antonescu CR, Singer S, Ladanyi M. Advances in sarcoma genomics and new therapeutic targets. Nat Rev Cancer 2011; 11:541-57. [PMID: 21753790 PMCID: PMC3361898 DOI: 10.1038/nrc3087] [Citation(s) in RCA: 308] [Impact Index Per Article: 23.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Increasingly, human mesenchymal malignancies are being classified by the abnormalities that drive their pathogenesis. Although many of these aberrations are highly prevalent within particular sarcoma subtypes, few are currently targeted therapeutically. Indeed, most subtypes of sarcoma are still treated with traditional therapeutic modalities, and in many cases sarcomas are resistant to adjuvant therapies. In this Review, we discuss the core molecular determinants of sarcomagenesis and emphasize the emerging genomic and functional genetic approaches that, coupled with novel therapeutic strategies, have the potential to transform the care of patients with sarcoma.
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Affiliation(s)
- Barry S Taylor
- Memorial Sloan-Kettering Cancer Center, New York, New York 10065, USA
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Au AYM, Hackl T, Yeager TR, Cohen SB, Pass HI, Harris CC, Reddel RR. Telomerase activity in pleural malignant mesotheliomas. Lung Cancer 2011; 73:283-8. [PMID: 21277646 DOI: 10.1016/j.lungcan.2010.12.023] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2010] [Accepted: 12/18/2010] [Indexed: 12/16/2022]
Abstract
New treatments are needed for malignant pleural mesothelioma (MPM), which currently has a poor prognosis. Cellular immortalisation, one of the hallmarks of cancer, depends on the activity of a telomere length maintenance mechanism (TMM) - either telomerase or alternative lengthening of telomeres (ALT). The TMMs are widely regarded as potential targets for cancer therapies and telomerase inhibitors have entered clinical trials. The aim of this study was to determine what proportion of MPMs use ALT and/or telomerase. Forty-three MPMs from 42 patients were examined for telomerase and ALT activity. Telomerase activity was detected by immunoaffinity purification followed by the telomere repeat amplification protocol (TRAP), and ALT activity was determined by the C-circle assay and by assessing telomere lengths using terminal restriction fragment analyses. We found that 43 of 43 MPMs were telomerase-positive[+] and ALT-negative[-]. Therefore, to investigate whether pleural mesothelial cells are unusually susceptible to activation of telomerase, we examined activation of the TMMs in an in vitro model of cellular immortalisation, in which normal pleural mesothelial cells were transduced with simian virus 40 (SV40) oncogenes. We found that normal mesothelial cells were TMM-negative, and that expression of the SV40 oncogenes did not directly activate telomerase or ALT. Immortalisation, which in this experimental system results from additional genetic changes that have not yet been identified, was accompanied by activation of either TMM. Therefore, pleural mesothelial cells are capable of activating either TMM in vitro, and the observation that 100% of MPMs were telomerase[+] suggests that there are factors in vivo that select for telomerase activity during oncogenesis of this tumour type. We conclude that MPM is a tumour that could be considered for anti-telomerase therapy.
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Affiliation(s)
- Amy Y M Au
- Children's Medical Research Institute, 214 Hawkesbury Road, Westmead, New South Wales 2145, Australia
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Lafferty-Whyte K, Bilsland A, Cairney CJ, Hanley L, Jamieson NB, Zaffaroni N, Oien KA, Burns S, Roffey J, Boyd SM, Keith WN. Scoring of senescence signalling in multiple human tumour gene expression datasets, identification of a correlation between senescence score and drug toxicity in the NCI60 panel and a pro-inflammatory signature correlating with survival advantage in peritoneal mesothelioma. BMC Genomics 2010; 11:532. [PMID: 20920304 PMCID: PMC3091681 DOI: 10.1186/1471-2164-11-532] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2010] [Accepted: 10/01/2010] [Indexed: 11/10/2022] Open
Abstract
Background Cellular senescence is a major barrier to tumour progression, though its role in pathogenesis of cancer and other diseases is poorly understood in vivo. Improved understanding of the degree to which latent senescence signalling persists in tumours might identify intervention strategies to provoke "accelerated senescence" responses as a therapeutic outcome. Senescence involves convergence of multiple pathways and requires ongoing dynamic signalling throughout its establishment and maintenance. Recent discovery of several new markers allows for an expression profiling approach to study specific senescence phenotypes in relevant tissue samples. We adopted a "senescence scoring" methodology based on expression profiles of multiple senescence markers to examine the degree to which signals of damage-associated or secretory senescence persist in various human tumours. Results We first show that scoring captures differential induction of damage or inflammatory pathways in a series of public datasets involving radiotherapy of colon adenocarcinoma, chemotherapy of breast cancer cells, replicative senescence of mesenchymal stem cells, and progression of melanoma. We extended these results to investigate correlations between senescence score and growth inhibition in response to ~1500 compounds in the NCI60 panel. Scoring of our own mesenchymal tumour dataset highlighted differential expression of secretory signalling pathways between distinct subgroups of MPNST, liposarcomas and peritoneal mesothelioma. Furthermore, a pro-inflammatory signature yielded by hierarchical clustering of secretory markers showed prognostic significance in mesothelioma. Conclusions We find that "senescence scoring" accurately reports senescence signalling in a variety of situations where senescence would be expected to occur and highlights differential expression of damage associated and secretory senescence pathways in a context-dependent manner.
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Affiliation(s)
- Kyle Lafferty-Whyte
- Centre for Oncology and Applied Pharmacology, University of Glasgow, Cancer Research UK Beatson Laboratories, Garscube Estate, Switchback Road, Bearsden, Glasgow G611BD, UK
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TCEAL7 inhibition of c-Myc activity in alternative lengthening of telomeres regulates hTERT expression. Neoplasia 2010; 12:405-14. [PMID: 20454512 DOI: 10.1593/neo.10180] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2010] [Revised: 03/03/2010] [Accepted: 03/05/2010] [Indexed: 11/18/2022] Open
Abstract
Replicative senescence forms a major barrier to tumor progression. Cancer cells bypass this by using one of the two known telomere maintenance mechanisms: telomerase or the recombination-based alternative lengthening of telomeres (ALT) mechanism. The molecular details of ALT are currently poorly understood. We have previously shown that telomerase is actively repressed through complex networks of kinase, gene expression, and chromatin regulation. In this study, we aimed to gain further understanding of the role of kinases in the regulation of telomerase expression in ALT cells. Using a whole human kinome small interfering RNA (siRNA) screen, we highlighted 106 kinases whose expression is linked to human telomerase reverse transcriptase (hTERT) promoter activity. Network modeling of transcriptional regulation implicated c-Myc as a key regulator of the 106 kinase hits. Given our previous observations of lower c-Myc activity in ALT cells, we further explored its potential to regulate telomerase expression in ALT. We found increased c-Myc binding at the hTERT promoter in telomerase-positive compared with ALT cells, although no expression differences in c-Myc, Mad, or Max were observed between ALT and telomerase-positive cells that could explain decreased c-Myc activity in ALT. Instead, we found increased expression of the c-Myc competitive inhibitor TCEAL7 in ALT cells and tumors and that alteration of TCEAL7 expression levels in ALT and telomerase-positive cells affects hTERT expression. Lower c-Myc activity in ALT may therefore be obtained through TCEAL7 regulation. Thus, TCEAL7 may present an interesting novel target for cancer therapy, which warrants further investigation.
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Degerman S, Siwicki JK, Osterman P, Lafferty-Whyte K, Keith WN, Roos G. Telomerase upregulation is a postcrisis event during senescence bypass and immortalization of two Nijmegen breakage syndrome T cell cultures. Aging Cell 2010; 9:220-35. [PMID: 20089118 DOI: 10.1111/j.1474-9726.2010.00550.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Our knowledge on immortalization and telomere biology is mainly based on genetically manipulated cells analyzed before and many population doublings post growth crisis. The general view is that growth crisis is telomere length (TL) dependent and that escape from crisis is coupled to increased expression of the telomerase reverse transcriptase (hTERT) gene, telomerase activity upregulation and TL stabilization. Here we have analyzed the process of spontaneous immortalization of human T cells, regarding pathways involved in senescence and telomerase regulation. Two Nijmegen breakage syndrome (NBS) T cell cultures (S3R and S4) showed gradual telomere attrition until a period of growth crisis followed by the outgrowth of immortalized cells. Whole genome expression analysis indicated differences between pre-, early post- and late postcrisis cells. Early postcrisis cells demonstrated a logarithmic growth curve, very short telomeres and, notably, no increase in hTERT or telomerase activity despite downregulation of several negative hTERT regulators (e.g. FOS, JUN D, SMAD3, RUNX2, TNF-a and TGFb-R2). Thereafter, cMYC mRNA increased in parallel with increased hTERT expression, telomerase activity and elongation of short telomeres, indicating a step-wise activation of hTERT transcription involving reduction of negative regulators followed by activation of positive regulator(s). Gene expression analysis indicated that cells escaped growth crisis by deregulated DNA damage response and senescence controlling genes, including downregulation of ATM, CDKN1B (p27), CDKN2D (p19) and ASF1A and upregulation of CDK4, TWIST1, TP73L (p63) and SYK. Telomerase upregulation was thus found to be uncoupled to escape of growth crisis but rather a later event in the immortalization process of NBS T cell cultures.
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Affiliation(s)
- Sofie Degerman
- Department of Medical Biosciences, Pathology, Umeå University, SE-90185 Umeå, Sweden
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Abstract
Unlimited cellular proliferation depends on counteracting the telomere attrition that accompanies DNA replication. In human cancers this usually occurs through upregulation of telomerase activity, but in 10-15% of cancers - including some with particularly poor outcome - it is achieved through a mechanism known as alternative lengthening of telomeres (ALT). ALT, which is dependent on homologous recombination, is therefore an important target for cancer therapy. Although dissection of the mechanism or mechanisms of ALT has been challenging, recent advances have led to the identification of several genes that are required for ALT and the elucidation of the biological significance of some phenotypic markers of ALT. This has enabled development of a rapid assay of ALT activity levels and the construction of molecular models of ALT.
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Abstract
Normal mammalian somatic cells proliferate a finite number of times in vitro before permanently withdrawing from the cell cycle into a cellular state referred to as senescence. Senescence may be triggered by excessive mitogenic stimulation or by various forms of cellular damage including excessive telomere shortening. Over the past decade, there has been continuing accumulation of evidence that senescence occurs in vivo, that it is relevant to aging and that it has a tumor suppressor function. However, the phenotype of senescence has also been found to include a number of puzzling features, including the secretion of proinflammatory factors that may foster tumorigenesis as well as the senescence of neighboring cells. On the basis of these antagonistic pro- and antitumorigenic effects, and of the observation that many viruses have developed proteins that prevent senescence of the cells they infect, it is argued that the primary function of senescence may have been as an antiviral defense mechanism. Recent progress in understanding how tumor cells evade senescence is also reviewed here.
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Affiliation(s)
- Roger R Reddel
- Cancer Research Unit, Children's Medical Research Institute, 214 Hawkesbury Road, Westmead, New South Wales 2145, Australia.
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