1
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Rosenberger LH, Riedel RF, Diego EJ, Nash AL, Grilley-Olson JE, Danziger NA, Sokol ES, Ross JS, Sammons SL. Genomic landscape of malignant phyllodes tumors reveals multiple targetable opportunities. Oncologist 2024:oyae218. [PMID: 39191445 DOI: 10.1093/oncolo/oyae218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2024] [Accepted: 07/19/2024] [Indexed: 08/29/2024] Open
Abstract
BACKGROUND Malignant phyllodes tumors (MPT) are rare fibroepithelial breast cancers with no known effective systemic therapy; metastatic progression portends a dismal prognosis. We sought to describe the genomic landscape of MPTs through genomic profiling and immunotherapeutic biomarker analysis. MATERIALS AND METHODS Cases of sequenced MPT were identified from a Clinical Laboratory Improvement Amendments-certified, College of American Pathologists-accredited laboratory (Foundation Medicine). All cases underwent genomic profiling using adaptor ligation-based, next-generation sequencing assay of 324 genes. Tumor agnostic immunotherapy biomarkers, microsatellite instability, tumor mutational burden (TMB), and programmed death-ligand 1 (PD-L1) expression were evaluated. Fisher's Exact Tests and analysis of variance were used to test for differences between groups and for continuous variables as appropriate. RESULTS Of 135 MPT cases identified; 94 (69.6%) were localized/locally recurrent and 41 (30.4%) were metastatic. Median age was 54 years (range 14-86). The median TMB was 2.5 mut/Mb and 3 were TMB-high (≥10 mut/Mb). 21.4% were PD-L1+ via Dako 22C3 assay (CPS ≥1). Most commonly altered genes included TERT-promoter (69.7%), CDKN2A (45.9%), TP53 (37.8%), NF1 (35.6%), CDKN2B (33.3%), MED12 (28.9%), MTAP (27.7%), KMT2D (22.2%), PIK3CA (20.0%), PTEN (18.5%), and RB1 (18.5%). Several tumors harboring genomic alterations with US Food and Drug Administration-approved indications in other tumor types were found including NF1, PIK3CA, EGFR Exon 19/20 insertions, and BRAF V600E mutations. CONCLUSIONS In the largest genomic evaluation of MPT to date, multiple clinically actionable mutations were found. Routine sequencing of metastatic MPT may provide additional information to guide treatment decisions and clinical trial enrollment.
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Affiliation(s)
- Laura H Rosenberger
- Department of Surgery, Duke University Medical Center, Durham, NC 27710, United States
- Duke Cancer Institute, Duke University, Durham, NC 27710, United States
| | - Richard F Riedel
- Duke Cancer Institute, Duke University, Durham, NC 27710, United States
- Department of Medicine, Duke University Medical Center, Durham, NC 27710, United States
| | - Emilia J Diego
- Department of Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA 15213, United States
| | - Amanda L Nash
- Department of Surgery, Duke University Medical Center, Durham, NC 27710, United States
| | - Juneko E Grilley-Olson
- Duke Cancer Institute, Duke University, Durham, NC 27710, United States
- Department of Medicine, Duke University Medical Center, Durham, NC 27710, United States
| | | | - Ethan S Sokol
- Foundation Medicine, Inc., Cambridge, MA 02141, United States
| | - Jeffrey S Ross
- Foundation Medicine, Inc., Cambridge, MA 02141, United States
- Department of Pathology, Urology, and Oncology, Upstate Medical University, Syracuse, NY 13210, United States
| | - Sarah L Sammons
- Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02215, United States
- Breast Oncology Program, Dana-Farber Brigham Cancer Center, Boston, MA 02215, United States
- Harvard Medical School, Boston, MA 02115, United States
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2
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Sanchez SE, Gu Y, Wang Y, Golla A, Martin A, Shomali W, Hockemeyer D, Savage SA, Artandi SE. Digital telomere measurement by long-read sequencing distinguishes healthy aging from disease. Nat Commun 2024; 15:5148. [PMID: 38890274 PMCID: PMC11189511 DOI: 10.1038/s41467-024-49007-4] [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: 10/25/2023] [Accepted: 05/21/2024] [Indexed: 06/20/2024] Open
Abstract
Telomere length is an important biomarker of organismal aging and cellular replicative potential, but existing measurement methods are limited in resolution and accuracy. Here, we deploy digital telomere measurement (DTM) by nanopore sequencing to understand how distributions of human telomere length change with age and disease. We measure telomere attrition and de novo elongation with up to 30 bp resolution in genetically defined populations of human cells, in blood cells from healthy donors and in blood cells from patients with genetic defects in telomere maintenance. We find that human aging is accompanied by a progressive loss of long telomeres and an accumulation of shorter telomeres. In patients with defects in telomere maintenance, the accumulation of short telomeres is more pronounced and correlates with phenotypic severity. We apply machine learning to train a binary classification model that distinguishes healthy individuals from those with telomere biology disorders. This sequencing and bioinformatic pipeline will advance our understanding of telomere maintenance mechanisms and the use of telomere length as a clinical biomarker of aging and disease.
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Affiliation(s)
- Santiago E Sanchez
- Stanford Cancer Institute, Stanford University School of Medicine, Stanford, CA, USA
- Cancer Biology Program, Stanford University School of Medicine, Stanford, CA, USA
- Medical Scientist Training Program, Stanford University, Stanford, CA, USA
- Department of Medicine, Stanford University School of Medicine, Stanford, CA, USA
- Department of Biochemistry, Stanford University School of Medicine, Stanford, CA, USA
| | - Yuchao Gu
- Stanford Cancer Institute, Stanford University School of Medicine, Stanford, CA, USA
- Department of Medicine, Stanford University School of Medicine, Stanford, CA, USA
- Department of Biochemistry, Stanford University School of Medicine, Stanford, CA, USA
| | - Yan Wang
- Stanford Cancer Institute, Stanford University School of Medicine, Stanford, CA, USA
- Department of Medicine, Stanford University School of Medicine, Stanford, CA, USA
- Department of Biochemistry, Stanford University School of Medicine, Stanford, CA, USA
| | - Anudeep Golla
- Stanford Cancer Institute, Stanford University School of Medicine, Stanford, CA, USA
| | - Annika Martin
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA
| | - William Shomali
- Department of Medicine, Stanford University School of Medicine, Stanford, CA, USA
| | - Dirk Hockemeyer
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA
- Chan Zuckerberg Biohub, San Francisco, CA, USA
- Innovative Genomics Institute, University of California, Berkeley, Berkeley, CA, USA
| | - Sharon A Savage
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, MD, USA
| | - Steven E Artandi
- Stanford Cancer Institute, Stanford University School of Medicine, Stanford, CA, USA.
- Department of Medicine, Stanford University School of Medicine, Stanford, CA, USA.
- Department of Biochemistry, Stanford University School of Medicine, Stanford, CA, USA.
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3
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Machitani M, Nomura A, Yamashita T, Yasukawa M, Ueki S, Fujita KI, Ueno T, Yamashita A, Tanzawa Y, Watanabe M, Taniguchi T, Saitoh N, Kaneko S, Kato Y, Mano H, Masutomi K. Maintenance of R-loop structures by phosphorylated hTERT preserves genome integrity. Nat Cell Biol 2024; 26:932-945. [PMID: 38806647 DOI: 10.1038/s41556-024-01427-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Accepted: 04/23/2024] [Indexed: 05/30/2024]
Abstract
As aberrant accumulation of RNA-DNA hybrids (R-loops) causes DNA damage and genome instability, cells express regulators of R-loop structures. Here we report that RNA-dependent RNA polymerase (RdRP) activity of human telomerase reverse transcriptase (hTERT) regulates R-loop formation. We found that the phosphorylated form of hTERT (p-hTERT) exhibits RdRP activity in nuclear speckles both in telomerase-positive cells and telomerase-negative cells with alternative lengthening of telomeres (ALT) activity. The p-hTERT did not associate with telomerase RNA component in nuclear speckles but, instead, with TERRA RNAs to resolve R-loops. Targeting of the TERT gene in ALT cells ablated RdRP activity and impaired tumour growth. Using a genome-scale CRISPR loss-of-function screen, we identified Fanconi anaemia/BRCA genes as synthetic lethal partners of hTERT RdRP. Inactivation of RdRP and Fanconi anaemia/BRCA genes caused accumulation of R-loop structures and DNA damage. These findings indicate that RdRP activity of p-hTERT guards against genome instability by removing R-loop structures.
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Affiliation(s)
- Mitsuhiro Machitani
- Division of Cancer Stem Cell, National Cancer Center Research Institute, Tokyo, Japan
| | - Akira Nomura
- Division of Cancer Stem Cell, National Cancer Center Research Institute, Tokyo, Japan
- Department of Orthopaedic Surgery, Surgical Science, Tokai University School of Medicine, Isehara, Japan
| | - Taro Yamashita
- Department of Gastroenterology, Kanazawa University Graduate School of Medical Sciences, Kanazawa, Japan
| | - Mami Yasukawa
- Division of Cancer Stem Cell, National Cancer Center Research Institute, Tokyo, Japan
| | - Saori Ueki
- Division of Cancer Stem Cell, National Cancer Center Research Institute, Tokyo, Japan
| | - Ken-Ichi Fujita
- Division of Cancer Stem Cell, National Cancer Center Research Institute, Tokyo, Japan
| | - Toshihide Ueno
- Division of Cellular Signaling, National Cancer Center Research Institute, Tokyo, Japan
| | - Akio Yamashita
- Department of Investigative Medicine, University of the Ryukyus Graduate School of Medicine, Nakagami, Japan
| | - Yoshikazu Tanzawa
- Department of Orthopaedic Surgery, Surgical Science, Tokai University School of Medicine, Isehara, Japan
| | - Masahiko Watanabe
- Department of Orthopaedic Surgery, Surgical Science, Tokai University School of Medicine, Isehara, Japan
| | - Toshiyasu Taniguchi
- Department of Molecular Life Science, Tokai University School of Medicine, Isehara, Japan
| | - Noriko Saitoh
- Division of Cancer Biology, The Cancer Institute of JFCR, Tokyo, Japan
| | - Shuichi Kaneko
- Department of Gastroenterology, Kanazawa University Graduate School of Medical Sciences, Kanazawa, Japan
| | - Yukinari Kato
- Department of Antibody Drug Development, Tohoku University Graduate School of Medicine, Sendai, Japan
- Department of Molecular Pharmacology, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Hiroyuki Mano
- Division of Cellular Signaling, National Cancer Center Research Institute, Tokyo, Japan
| | - Kenkichi Masutomi
- Division of Cancer Stem Cell, National Cancer Center Research Institute, Tokyo, Japan.
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4
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Ghosh PK, Rao MJ, Putta CL, Ray S, Rengan AK. Telomerase: a nexus between cancer nanotherapy and circadian rhythm. Biomater Sci 2024; 12:2259-2281. [PMID: 38596876 DOI: 10.1039/d4bm00024b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/11/2024]
Abstract
Cancer represents a complex disease category defined by the unregulated proliferation and dissemination of anomalous cells within the human body. According to the GLOBOCAN 2020 report, the year 2020 witnessed the diagnosis of approximately 19.3 million new cases of cancer and 10.0 million individuals succumbed to the disease. A typical cell eventually becomes cancerous because of a long-term buildup of genetic instability and replicative immortality. Telomerase is a crucial regulator of cancer progression as it induces replicative immortality. In cancer cells, telomerase inhibits apoptosis by elongating the length of the telomeric region, which usually protects the genome from shortening. Many nanoparticles are documented as being available for detecting the presence of telomerase, and many were used as delivery systems to transport drugs. Furthermore, telomere homeostasis is regulated by the circadian time-keeping machinery, leading to 24-hour rhythms in telomerase activity and TERT mRNA expression in mammals. This review provides a comprehensive discussion of various kinds of nanoparticles used in telomerase detection, inhibition, and multiple drug-related pathways, as well as enlightens an imperative association between circadian rhythm and telomerase activity from the perspective of nanoparticle-based anticancer therapeutics.
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Affiliation(s)
- Pramit Kumar Ghosh
- Department of Biomedical Engineering, Indian Institute of Technology (IIT), Hyderabad, India.
| | - Maddila Jagapathi Rao
- Department of Biomedical Engineering, Indian Institute of Technology (IIT), Hyderabad, India.
| | - Chandra Lekha Putta
- Department of Biomedical Engineering, Indian Institute of Technology (IIT), Hyderabad, India.
| | - Sandipan Ray
- Department of Biotechnology, Indian Institute of Technology (IIT), Hyderabad, India.
| | - Aravind Kumar Rengan
- Department of Biomedical Engineering, Indian Institute of Technology (IIT), Hyderabad, India.
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5
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Olovnikov IA. Alexey Olovnikov: theoretical biology beyond the margins. Biogerontology 2024; 25:195-203. [PMID: 37676438 DOI: 10.1007/s10522-023-10061-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Accepted: 08/03/2023] [Indexed: 09/08/2023]
Abstract
Alexey Olovnikov (1936-2022) is an author of the famous marginotomy hypothesis, where he recognized the DNA end replication problem and its role in cell aging. In this biographical note we celebrate the 50th anniversary of this theoretical discovery that later enjoyed a brilliant confirmation and gave rise to a new thriving field of molecular biology and gerontology. We also take a look at the evolution of ideas in Alexey Olovnikov's lifelong quest to uncover the molecular mechanisms of aging, exploring the reasons why he walked away from his initial conclusion about the key role of telomeres in aging, and built a new vast theoretical landscape that linked all stages of ontogenesis.
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6
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Bartle L, Wellinger RJ. Methods that shaped telomerase research. Biogerontology 2024; 25:249-263. [PMID: 37903970 PMCID: PMC10998806 DOI: 10.1007/s10522-023-10073-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Accepted: 09/30/2023] [Indexed: 11/01/2023]
Abstract
Telomerase, the ribonucleoprotein (RNP) responsible for telomere maintenance, has a complex life. Complex in that it is made of multiple proteins and an RNA, and complex because it undergoes many changes, and passes through different cell compartments. As such, many methods have been developed to discover telomerase components, delve deep into understanding its structure and function and to figure out how telomerase biology ultimately relates to human health and disease. While some old gold-standard methods are still key for determining telomere length and measuring telomerase activity, new technologies are providing promising new ways to gain detailed information that we have never had access to before. Therefore, we thought it timely to briefly review the methods that have revealed information about the telomerase RNP and outline some of the remaining questions that could be answered using new methodology.
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Affiliation(s)
- Louise Bartle
- Department of Microbiology and Infectious Diseases, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Applied Cancer Research Pavilion, 3201 rue Jean-Mignault, Sherbrooke, QC, J1E 4K8, Canada
| | - Raymund J Wellinger
- Department of Microbiology and Infectious Diseases, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Applied Cancer Research Pavilion, 3201 rue Jean-Mignault, Sherbrooke, QC, J1E 4K8, Canada.
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7
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Zhang J, Zhang F, Porter KI, Dakup PP, Wang S, Robertson GP, Gaddameedhi S, Zhu J. Telomere dysfunction in Tert knockout mice delays Braf V600E -induced melanoma development. Int J Cancer 2024; 154:548-560. [PMID: 37727982 PMCID: PMC10840707 DOI: 10.1002/ijc.34713] [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: 01/13/2023] [Revised: 07/27/2023] [Accepted: 07/31/2023] [Indexed: 09/21/2023]
Abstract
Telomerase activation is a crucial step in melanomagenesis, often occurring because of ultraviolet radiation (UVR)-induced mutations at the telomerase gene (TERT) promoter and rendering TERT transcription in response to the activated Raf-MAP kinase pathway by BRAFV600E mutation. Due to the excessively long telomeres in mice, this process does not occur during melanomagenesis in mouse models. To investigate the impact of telomere dysfunction on melanomagenesis, BrafV600E was induced in generations 1 and 4 (G1 and G4) of Tert-/- mice. Our findings revealed that, regardless of UVR exposure, melanoma development was delayed in G4 mice, which had shorter telomeres compared to G1 and wild-type C57BL/6J (G0) mice. Moreover, many G4 tumors displayed an accumulation of excessive DNA damage, as evidenced by increased γH2A.X staining. Tumors from UVR-exposed mice exhibited elevated p53 protein expression. Cultured tumor cells isolated from G4 mice displayed abundant chromosomal fusions and rearrangements, indicative of telomere dysfunction in these cells. Additionally, tumor cells derived from UVB-exposed mice exhibited constitutively elevated expression of mutant p53 proteins, suggesting that p53 was a target of UVB-induced mutagenesis. Taken together, our findings suggest that telomere dysfunction hampers melanomagenesis, and targeting telomere crisis-mediated genomic instability may hold promise for the prevention and treatment of melanoma.
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Affiliation(s)
- Jinglong Zhang
- Department of Pharmaceutical Sciences, Washington State University, Spokane, WA 99210, USA
| | - Fan Zhang
- Department of Pharmaceutical Sciences, Washington State University, Spokane, WA 99210, USA
| | - Kenneth I. Porter
- Department of Pharmaceutical Sciences, Washington State University, Spokane, WA 99210, USA
| | - Panshak P. Dakup
- Department of Pharmaceutical Sciences, Washington State University, Spokane, WA 99210, USA
- Department of Biological Sciences, Center for Human Health and the Environment, North Carolina State University, Raleigh, NC 27606, USA
| | - Shuwen Wang
- Department of Pharmaceutical Sciences, Washington State University, Spokane, WA 99210, USA
| | - Gavin P. Robertson
- Department of Pharmacology, Pennsylvania State University College of Medicine, Hershey, PA 17033, USA
| | - Shobhan Gaddameedhi
- Department of Biological Sciences, Center for Human Health and the Environment, North Carolina State University, Raleigh, NC 27606, USA
| | - Jiyue Zhu
- Department of Pharmaceutical Sciences, Washington State University, Spokane, WA 99210, USA
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8
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Liu M, Zhang Y, Jian Y, Gu L, Zhang D, Zhou H, Wang Y, Xu ZX. The regulations of telomerase reverse transcriptase (TERT) in cancer. Cell Death Dis 2024; 15:90. [PMID: 38278800 PMCID: PMC10817947 DOI: 10.1038/s41419-024-06454-7] [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: 09/22/2023] [Revised: 01/04/2024] [Accepted: 01/08/2024] [Indexed: 01/28/2024]
Abstract
Abnormal activation of telomerase occurs in most cancer types, which facilitates escaping from cell senescence. As the key component of telomerase, telomerase reverse transcriptase (TERT) is regulated by various regulation pathways. TERT gene changing in its promoter and phosphorylation respectively leads to TERT ectopic expression at the transcription and protein levels. The co-interacting factors play an important role in the regulation of TERT in different cancer types. In this review, we focus on the regulators of TERT and these downstream functions in cancer regulation. Determining the specific regulatory mechanism will help to facilitate the development of a cancer treatment strategy that targets telomerase and cancer cell senescence. As the most important catalytic subunit component of telomerase, TERT is rapidly regulated by transcriptional factors and PTM-related activation. These changes directly influence TERT-related telomere maintenance by regulating telomerase activity in telomerase-positive cancer cells, telomerase assembly with telomere-binding proteins, and recruiting telomerase to the telomere. Besides, there are also non-canonical functions that are influenced by TERT, including the basic biological functions of cancer cells, such as proliferation, apoptosis, cell cycle regulation, initiating cell formation, EMT, and cell invasion. Other downstream effects are the results of the influence of transcriptional factors by TERT. Currently, some small molecular inhibitors of TERT and TERT vaccine are under research as a clinical therapeutic target. Purposeful work is in progress.
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Affiliation(s)
- Mingdi Liu
- Key Laboratory of Pathobiology, Ministry of Education, Jilin University, Changchun, 130021, Jilin, China
| | - Yuning Zhang
- Key Laboratory of Pathobiology, Ministry of Education, Jilin University, Changchun, 130021, Jilin, China
| | - Yongping Jian
- Key Laboratory of Pathobiology, Ministry of Education, Jilin University, Changchun, 130021, Jilin, China
| | - Liting Gu
- Key Laboratory of Pathobiology, Ministry of Education, Jilin University, Changchun, 130021, Jilin, China
| | - Dan Zhang
- Key Laboratory of Pathobiology, Ministry of Education, Jilin University, Changchun, 130021, Jilin, China
| | - Honglan Zhou
- Department of Urology, The First Hospital of Jilin University, Changchun, 130021, Jilin, China.
| | - Yishu Wang
- Key Laboratory of Pathobiology, Ministry of Education, Jilin University, Changchun, 130021, Jilin, China.
| | - Zhi-Xiang Xu
- Key Laboratory of Pathobiology, Ministry of Education, Jilin University, Changchun, 130021, Jilin, China.
- Department of Urology, The First Hospital of Jilin University, Changchun, 130021, Jilin, China.
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9
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Ghanim GE, Sekne Z, Balch S, van Roon AMM, Nguyen THD. 2.7 Å cryo-EM structure of human telomerase H/ACA ribonucleoprotein. Nat Commun 2024; 15:746. [PMID: 38272871 PMCID: PMC10811338 DOI: 10.1038/s41467-024-45002-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Accepted: 01/03/2024] [Indexed: 01/27/2024] Open
Abstract
Telomerase is a ribonucleoprotein (RNP) enzyme that extends telomeric repeats at eukaryotic chromosome ends to counterbalance telomere loss caused by incomplete genome replication. Human telomerase is comprised of two distinct functional lobes tethered by telomerase RNA (hTR): a catalytic core, responsible for DNA extension; and a Hinge and ACA (H/ACA) box RNP, responsible for telomerase biogenesis. H/ACA RNPs also have a general role in pseudouridylation of spliceosomal and ribosomal RNAs, which is critical for the biogenesis of the spliceosome and ribosome. Much of our structural understanding of eukaryotic H/ACA RNPs comes from structures of the human telomerase H/ACA RNP. Here we report a 2.7 Å cryo-electron microscopy structure of the telomerase H/ACA RNP. The significant improvement in resolution over previous 3.3 Å to 8.2 Å structures allows us to uncover new molecular interactions within the H/ACA RNP. Many disease mutations are mapped to these interaction sites. The structure also reveals unprecedented insights into a region critical for pseudouridylation in canonical H/ACA RNPs. Together, our work advances understanding of telomerase-related disease mutations and the mechanism of pseudouridylation by eukaryotic H/ACA RNPs.
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Affiliation(s)
| | - Zala Sekne
- MRC Laboratory of Molecular Biology, Cambridge, CB2 0QH, UK
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10
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Yang R, Hu J, Zhang L, Liu X, Huang Y, Zhang L, Fan Q. Recent advances in optical biosensing and imaging of telomerase activity and relevant signal amplification strategies. Analyst 2024; 149:290-303. [PMID: 38099470 DOI: 10.1039/d3an01900d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
Telomerase as a new valuable biomarker for early diagnosis and prognosis evaluation of cancer has attracted much interest in the field of biosensors, cell imaging, and drug screening. In this review, we mainly focus on different optical techniques and various signal amplification strategies for telomerase activity determination. Fluorometric, colorimetry, chemiluminescence, surface-enhanced Raman scattering (SERS), and dual-mode techniques for telomerase sensing and imaging are summarized. Signal amplification strategies include two categories: one is nucleic acid-based amplification, such as rolling circle amplification (RCA), the hybridization chain reaction (HCR), and catalytic hairpin assembly (CHA); the other is nanomaterial-assisted amplification, including metal nanoclusters, quantum dots, transition metal compounds, graphene oxide, and DNA nanomaterials. Challenges and prospects are also discussed to provide new insights for future development of multifunctional strategies and techniques for in situ and in vivo analysis of biomarkers for accurate cancer diagnosis.
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Affiliation(s)
- Ruining Yang
- The State Key Laboratory of Organic Electronics and Information Displays & Jiangsu Key Laboratory for Biosensors, Institute of Advanced Materials (IAM), Nanjing University of Posts & Telecommunications, 9 Wenyuan Road, Nanjing 210023, China.
| | - Junbo Hu
- The State Key Laboratory of Organic Electronics and Information Displays & Jiangsu Key Laboratory for Biosensors, Institute of Advanced Materials (IAM), Nanjing University of Posts & Telecommunications, 9 Wenyuan Road, Nanjing 210023, China.
| | - Longsheng Zhang
- The State Key Laboratory of Organic Electronics and Information Displays & Jiangsu Key Laboratory for Biosensors, Institute of Advanced Materials (IAM), Nanjing University of Posts & Telecommunications, 9 Wenyuan Road, Nanjing 210023, China.
| | - Xingfen Liu
- The State Key Laboratory of Organic Electronics and Information Displays & Jiangsu Key Laboratory for Biosensors, Institute of Advanced Materials (IAM), Nanjing University of Posts & Telecommunications, 9 Wenyuan Road, Nanjing 210023, China.
| | - Yanqin Huang
- The State Key Laboratory of Organic Electronics and Information Displays & Jiangsu Key Laboratory for Biosensors, Institute of Advanced Materials (IAM), Nanjing University of Posts & Telecommunications, 9 Wenyuan Road, Nanjing 210023, China.
| | - Lei Zhang
- The State Key Laboratory of Organic Electronics and Information Displays & Jiangsu Key Laboratory for Biosensors, Institute of Advanced Materials (IAM), Nanjing University of Posts & Telecommunications, 9 Wenyuan Road, Nanjing 210023, China.
| | - Quli Fan
- The State Key Laboratory of Organic Electronics and Information Displays & Jiangsu Key Laboratory for Biosensors, Institute of Advanced Materials (IAM), Nanjing University of Posts & Telecommunications, 9 Wenyuan Road, Nanjing 210023, China.
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11
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Lim CJ. Telomere C-Strand Fill-In Machinery: New Insights into the Human CST-DNA Polymerase Alpha-Primase Structures and Functions. Subcell Biochem 2024; 104:73-100. [PMID: 38963484 DOI: 10.1007/978-3-031-58843-3_5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/05/2024]
Abstract
Telomeres at the end of eukaryotic chromosomes are extended by a specialized set of enzymes and telomere-associated proteins, collectively termed here the telomere "replisome." The telomere replisome acts on a unique replicon at each chromosomal end of the telomeres, the 3' DNA overhang. This telomere replication process is distinct from the replisome mechanism deployed to duplicate the human genome. The G-rich overhang is first extended before the complementary C-strand is filled in. This overhang is extended by telomerase, a specialized ribonucleoprotein and reverse transcriptase. The overhang extension process is terminated when telomerase is displaced by CTC1-STN1-TEN1 (CST), a single-stranded DNA-binding protein complex. CST then recruits DNA polymerase α-primase to complete the telomere replication process by filling in the complementary C-strand. In this chapter, the recent structure-function insights into the human telomere C-strand fill-in machinery (DNA polymerase α-primase and CST) will be discussed.
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Affiliation(s)
- Ci Ji Lim
- Department of Biochemistry, College of Agricultural and Life Sciences, University of Wisconsin-Madison, Madison, WI, USA.
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12
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Sanchez SE, Gu J, Golla A, Martin A, Shomali W, Hockemeyer D, Savage SA, Artandi SE. Digital telomere measurement by long-read sequencing distinguishes healthy aging from disease. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.29.569263. [PMID: 38077053 PMCID: PMC10705489 DOI: 10.1101/2023.11.29.569263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/23/2023]
Abstract
Telomere length is an important biomarker of organismal aging and cellular replicative potential, but existing measurement methods are limited in resolution and accuracy. Here, we deploy digital telomere measurement by nanopore sequencing to understand how distributions of human telomere length change with age and disease. We measure telomere attrition and de novo elongation with unprecedented resolution in genetically defined populations of human cells, in blood cells from healthy donors and in blood cells from patients with genetic defects in telomere maintenance. We find that human aging is accompanied by a progressive loss of long telomeres and an accumulation of shorter telomeres. In patients with defects in telomere maintenance, the accumulation of short telomeres is more pronounced and correlates with phenotypic severity. We apply machine learning to train a binary classification model that distinguishes healthy individuals from those with telomere biology disorders. This sequencing and bioinformatic pipeline will advance our understanding of telomere maintenance mechanisms and the use of telomere length as a clinical biomarker of aging and disease.
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Affiliation(s)
- Santiago E. Sanchez
- Stanford Cancer Institute, Stanford University School of Medicine; Stanford, CA, USA
- Cancer Biology Program, Stanford University School of Medicine; Stanford, CA, USA
- Medical Scientist Training Program, Stanford University; Stanford CA, USA
| | - Jessica Gu
- Stanford Cancer Institute, Stanford University School of Medicine; Stanford, CA, USA
- Department of Medicine, Stanford University School of Medicine; Stanford, CA, USA
- Department of Biochemistry, Stanford University School of Medicine; Stanford, CA, USA
| | - Anudeep Golla
- Stanford Cancer Institute, Stanford University School of Medicine; Stanford, CA, USA
| | - Annika Martin
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA
| | - William Shomali
- Department of Medicine, Stanford University School of Medicine; Stanford, CA, USA
| | - Dirk Hockemeyer
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA
- Chan Zuckerberg Biohub, San Francisco, CA
- Innovative Genomics Institute, University of California, Berkeley, Berkeley, CA
| | - Sharon A. Savage
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, Maryland, USA
| | - Steven E. Artandi
- Stanford Cancer Institute, Stanford University School of Medicine; Stanford, CA, USA
- Department of Medicine, Stanford University School of Medicine; Stanford, CA, USA
- Department of Biochemistry, Stanford University School of Medicine; Stanford, CA, USA
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13
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Han H, Park C, Lee CY, Ahn JK. Background-filtered telomerase activity assay with cyclic DNA cleavage amplification. NANOSCALE 2023; 15:16669-16674. [PMID: 37801026 DOI: 10.1039/d3nr04132h] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/07/2023]
Abstract
Overexpression of telomerase incites the abnormal proliferation of cancer cells. Thus, it has been regarded as a cancer biomarker and a potential therapeutic target. Existing assays suggest a promising sensing scheme to detect telomerase activity. However, they are complicated in terms of assay preparation and implementation. We herein report a Quenching-Exempt invader Signal Amplification Test, termed 'QUEST'. The assay leverages on a high turnover, specific cleaving enzyme, flap endonuclease I (FEN1), and graphene oxide (GO) for background (BG) filtering. In response to the target, FEN1 significantly boosts the signal with invader signal amplification. To distinguish the target signal, GO filters out the BG. It captures residual reporter invader probes (RP) to quench undesired signals. QUEST is straightforward without any pre-preparatory steps and washing/separation. Its probe design is simple and cost-effective. With QUEST, we investigated telomerase activities in various cell lines. Notably, we discriminated cancer cell lines from normal cell lines. In addition, a candidate inhibitor for telomerase was screened, which showed the promising potential of QUEST in real applications.
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Affiliation(s)
- Hyogu Han
- Material & Component Convergence R&D Department, Korea Institute of Industrial Technology (KITECH), Ansan 15588, Korea
- Department of Chemistry, Gangneung-Wonju National University, Gangneung 25457, Korea
| | - Chihyun Park
- Daejeon District Office, National Forensic Service, Daejeon 34054, Korea
| | - Chang Yeol Lee
- Bionanotechnology Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, Korea
| | - Jun Ki Ahn
- Material & Component Convergence R&D Department, Korea Institute of Industrial Technology (KITECH), Ansan 15588, Korea
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14
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Sharaf R, Jin DX, Grady J, Napier C, Ebot E, Frampton GM, Albacker LA, Thomas DM, Montesion M. A pan-sarcoma landscape of telomeric content shows that alterations in RAD51B and GID4 are associated with higher telomeric content. NPJ Genom Med 2023; 8:26. [PMID: 37709802 PMCID: PMC10502097 DOI: 10.1038/s41525-023-00369-6] [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: 05/17/2023] [Accepted: 08/18/2023] [Indexed: 09/16/2023] Open
Abstract
Tumor cells need to activate a telomere maintenance mechanism, enabling limitless replication. The bulk of evidence supports that sarcomas predominantly use alternative lengthening of telomeres (ALT) mechanism, commonly associated with alterations in ATRX and DAXX. In our dataset, only 12.3% of sarcomas harbored alterations in these genes. Thus, we checked for the presence of other genomic determinants of high telomeric content in sarcomas. Our dataset consisted of 13555 sarcoma samples, sequenced as a part of routine clinical care on the FoundationOne®Heme platform. We observed a median telomeric content of 622.3 telomeric reads per GC-matched million reads (TRPM) across all samples. In agreement with previous studies, telomeric content was significantly higher in ATRX altered and POT1 altered sarcomas. We further observed that sarcomas with alterations in RAD51B or GID4 were enriched in samples with high telomeric content, specifically within uterus leiomyosarcoma for RAD51B and soft tissue sarcoma (not otherwise specified, nos) for GID4, Furthermore, RAD51B and POT1 alterations were mutually exclusive with ATRX and DAXX alterations, suggestive of functional redundancy. Our results propose a role played by RAD51B and GID4 in telomere elongation in sarcomas and open research opportunities for agents aimed at targeting this critical pathway in tumorigenesis.
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Affiliation(s)
| | | | - John Grady
- Omico Australian Genomic Cancer Medicine, Sydney, Australia
- Garvan Institute of Medical Research, Sydney, Australia
- St Vincent's Clinical School, University of New South Wales, Sydney, Australia
| | - Christine Napier
- Omico Australian Genomic Cancer Medicine, Sydney, Australia
- Garvan Institute of Medical Research, Sydney, Australia
- St Vincent's Clinical School, University of New South Wales, Sydney, Australia
| | - Ericka Ebot
- Foundation Medicine Inc., Cambridge, MA, USA
| | | | | | - David M Thomas
- Omico Australian Genomic Cancer Medicine, Sydney, Australia
- Garvan Institute of Medical Research, Sydney, Australia
- St Vincent's Clinical School, University of New South Wales, Sydney, Australia
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15
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Ali JH, Walter M. Combining old and new concepts in targeting telomerase for cancer therapy: transient, immediate, complete and combinatory attack (TICCA). Cancer Cell Int 2023; 23:197. [PMID: 37679807 PMCID: PMC10483736 DOI: 10.1186/s12935-023-03041-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Accepted: 08/25/2023] [Indexed: 09/09/2023] Open
Abstract
Telomerase can overcome replicative senescence by elongation of telomeres but is also a specific element in most cancer cells. It is expressed more vastly than any other tumor marker. Telomerase as a tumor target inducing replicative immortality can be overcome by only one other mechanism: alternative lengthening of telomeres (ALT). This limits the probability to develop resistance to treatments. Moreover, telomerase inhibition offers some degree of specificity with a low risk of toxicity in normal cells. Nevertheless, only one telomerase antagonist reached late preclinical studies. The underlying causes, the pitfalls of telomerase-based therapies, and future chances based on recent technical advancements are summarized in this review. Based on new findings and approaches, we propose a concept how long-term survival in telomerase-based cancer therapies can be significantly improved: the TICCA (Transient Immediate Complete and Combinatory Attack) strategy.
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Affiliation(s)
- Jaber Haj Ali
- Institute of Laboratory Medicine, Clinical Chemistry and Pathobiochemistry, Charité Universitätsmedizin Berlin, Augustenburger Platz 1, 13353, Berlin, Germany
- Institute of Clinical Chemistry and Laboratory Medicine, Universitätsmedizin Rostock, Ernst-Heydemann-Straße 6, 18057, Rostock, Germany
| | - Michael Walter
- Institute of Clinical Chemistry and Laboratory Medicine, Universitätsmedizin Rostock, Ernst-Heydemann-Straße 6, 18057, Rostock, Germany.
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16
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Kim JJ, Sayed ME, Ahn A, Slusher AL, Ying JY, Ludlow AT. Dynamics of TERT regulation via alternative splicing in stem cells and cancer cells. PLoS One 2023; 18:e0289327. [PMID: 37531400 PMCID: PMC10395990 DOI: 10.1371/journal.pone.0289327] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 07/17/2023] [Indexed: 08/04/2023] Open
Abstract
Part of the regulation of telomerase activity includes the alternative splicing (AS) of the catalytic subunit telomerase reverse transcriptase (TERT). Although a therapeutic window for telomerase/TERT inhibition exists between cancer cells and somatic cells, stem cells express TERT and rely on telomerase activity for physiological replacement of cells. Therefore, identifying differences in TERT regulation between stem cells and cancer cells is essential for developing telomerase inhibition-based cancer therapies that reduce damage to stem cells. In this study, we measured TERT splice variant expression and telomerase activity in induced pluripotent stem cells (iPSCs), neural progenitor cells (NPCs), and non-small cell lung cancer cells (NSCLC, Calu-6 cells). We observed that a NOVA1-PTBP1-PTBP2 axis regulates TERT alternative splicing (AS) in iPSCs and their differentiation into NPCs. We also found that splice-switching of TERT, which regulates telomerase activity, is induced by different cell densities in stem cells but not cancer cells. Lastly, we identified cell type-specific splicing factors that regulate TERT AS. Overall, our findings represent an important step forward in understanding the regulation of TERT AS in stem cells and cancer cells.
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Affiliation(s)
- Jeongjin J. Kim
- School of Kinesiology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Mohammed E. Sayed
- School of Kinesiology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Alexander Ahn
- School of Kinesiology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Aaron L. Slusher
- School of Kinesiology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Jeffrey Y. Ying
- School of Kinesiology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Andrew T. Ludlow
- School of Kinesiology, University of Michigan, Ann Arbor, Michigan, United States of America
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17
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Lue NF, Autexier C. Orchestrating nucleic acid-protein interactions at chromosome ends: telomerase mechanisms come into focus. Nat Struct Mol Biol 2023; 30:878-890. [PMID: 37400652 PMCID: PMC10539978 DOI: 10.1038/s41594-023-01022-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Accepted: 05/16/2023] [Indexed: 07/05/2023]
Abstract
Telomerase is a special reverse transcriptase ribonucleoprotein dedicated to the synthesis of telomere repeats that protect chromosome ends. Among reverse transcriptases, telomerase is unique in using a stably associated RNA with an embedded template to synthesize a specified sequence. Moreover, it is capable of iteratively copying the same template region (repeat addition processivity) through multiple rounds of RNA-DNA unpairing and reannealing, that is, the translocation reaction. Biochemical analyses of telomerase over the past 3 decades in protozoa, fungi and mammals have identified structural elements that underpin telomerase mechanisms and have led to models that account for the special attributes of telomerase. Notably, these findings and models can now be interpreted and adjudicated through recent cryo-EM structures of Tetrahymena and human telomerase holoenzyme complexes in association with substrates and regulatory proteins. Collectively, these structures reveal the intricate protein-nucleic acid interactions that potentiate telomerase's unique translocation reaction and clarify how this enzyme reconfigures the basic reverse transcriptase scaffold to craft a polymerase dedicated to the synthesis of telomere DNA. Among the many new insights is the resolution of the telomerase 'anchor site' proposed more than 3 decades ago. The structures also highlight the nearly universal conservation of a protein-protein interface between an oligonucleotide/oligosaccharide-binding (OB)-fold regulatory protein and the telomerase catalytic subunit, which enables spatial and temporal regulation of telomerase function in vivo. In this Review, we discuss key features of the structures in combination with relevant functional analyses. We also examine conserved and divergent aspects of telomerase mechanisms as gleaned from studies in different model organisms.
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Affiliation(s)
- Neal F Lue
- Department of Microbiology and Immunology, Weill Cornell Medicine, New York, NY, USA.
| | - Chantal Autexier
- Lady Davis Institute for Medical Research, Jewish General Hospital and Department of Anatomy and Cell Biology and Department of Medicine, McGill University, Montreal, Quebec, Canada.
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18
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Rubiano EGO, Baldoncini M, Cómbita AL, Payán-Gómez C, Gómez-Amarillo DF, Hakim F, Figueredo LF, Forlizzi V, Rangel CC, Luzzi S, Campero A, Parra-Medina R. Understanding the molecular profiling of diffuse gliomas classification: A brief overview. Surg Neurol Int 2023; 14:225. [PMID: 37404501 PMCID: PMC10316154 DOI: 10.25259/sni_209_2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2023] [Accepted: 06/04/2023] [Indexed: 07/06/2023] Open
Abstract
Background Gliomas represent almost 30% of all primary brain tumors and account for 80% of malignant primary ones. In the last two decades, significant progress has been made in understanding gliomas' molecular origin and development. These advancements have demonstrated a remarkable improvement in classification systems based on mutational markers, which contribute paramount information in addition to traditional histology-based classification. Methods We performed a narrative review of the literature including each molecular marker described for adult diffuse gliomas used in the World Health Organization (WHO) central nervous system 5. Results The 2021 WHO classification of diffuse gliomas encompasses many molecular aspects considered in the latest proposed hallmarks of cancer. The outcome of patients with diffuse gliomas relies on their molecular behavior and consequently, to determine clinical outcomes for these patients, molecular profiling should be mandatory. At least, the following molecular markers are necessary for the current most accurate classification of these tumors: (1) isocitrate dehydrogenase (IDH) IDH-1 mutation, (2) 1p/19q codeletion, (3) cyclin-dependent kinase inhibitor 2A/B deletion, (4) telomerase reverse transcriptase promoter mutation, (5) α-thalassemia/ mental retardation syndrome X-linked loss, (6) epidermal growth factor receptor amplification, and (7) tumor protein P53 mutation. These molecular markers have allowed the differentiation of multiple variations of the same disease, including the differentiation of distinct molecular Grade 4 gliomas. This could imply different clinical outcomes and possibly impact targeted therapies in the years to come. Conclusion Physicians face different challenging scenarios according to the clinical features of patients with gliomas. In addition to the current advances in clinical decision-making, including radiological and surgical techniques, understanding the disease's molecular pathogenesis is paramount to improving the benefits of its clinical treatments. This review aims to describe straightforwardly the most remarkable aspects of the molecular pathogenesis of diffuse gliomas.
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Affiliation(s)
- Edgar G. Ordóñez Rubiano
- Department of Neurological Surgery, Fundación Universitaria de Ciencias de la Salud, Hospital de San José - Sociedad de Cirugía de Bogotá, Bogotá, Colombia
- School of Medicine, Universidad Nacional de Colombia, Bogotá, Colombia
- Research Institute, Fundación Universitaria de Ciencias de la Salud, Bogotá, Colombia
| | - Matías Baldoncini
- Department of Neurosurgery, San Fernando Hospital, San Fernando, Argentina
| | - Alba Lucía Cómbita
- Departament of Microbiology, Universidad Nacional de Colombia, Bogotá, Colombia
- Translational Research Group in Oncology, Instituto Nacional de Cancerología, Bogotá, Colombia
| | - César Payán-Gómez
- Academic direction, Universidad Nacional de Colombia - Sede de La Paz, La Paz, Colombia
| | - Diego F. Gómez-Amarillo
- Department of Neurosurgery, Hospital Universitario Fundación Santa Fé de Bogotá, Bogotá, Colombia
| | - Fernando Hakim
- Department of Neurosurgery, Hospital Universitario Fundación Santa Fé de Bogotá, Bogotá, Colombia
| | | | - Valeria Forlizzi
- Department of Anatomy, University of Buenos Aires, Buenos Aires, Argentina
| | - Carlos Castillo Rangel
- Department of Neurosurgery, Instituto de Seguridad y Servicios Sociales de los Trabajadores del Estado, Mexico City, Mexico
| | - Sabino Luzzi
- Department of Neurosurgery, University of Pavia, Polo Didattico “Cesare Brusotti”, Pavia, Italy
| | | | - Rafael Parra-Medina
- Research Institute, Fundación Universitaria de Ciencias de la Salud, Bogotá, Colombia
- Department of Pathology, Instituto Nacional de Cancerología Bogotá, Bogotá, Colombia
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19
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Zhao Y, Ye X, Xiong Z, Ihsan A, Ares I, Martínez M, Lopez-Torres B, Martínez-Larrañaga MR, Anadón A, Wang X, Martínez MA. Cancer Metabolism: The Role of ROS in DNA Damage and Induction of Apoptosis in Cancer Cells. Metabolites 2023; 13:796. [PMID: 37512503 PMCID: PMC10383295 DOI: 10.3390/metabo13070796] [Citation(s) in RCA: 21] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 06/21/2023] [Accepted: 06/23/2023] [Indexed: 07/30/2023] Open
Abstract
Cancer is a huge challenge for people worldwide. High reactive oxygen species (ROS) levels are a recognized hallmark of cancer and an important aspect of cancer treatment research. Abnormally elevated ROS levels are often attributable to alterations in cellular metabolic activities and increased oxidative stress, which affects both the development and maintenance of cancer. Moderately high levels of ROS are beneficial to maintain tumor cell genesis and development, while toxic levels of ROS have been shown to be an important force in destroying cancer cells. ROS has become an important anticancer target based on the proapoptotic effect of toxic levels of ROS. Therefore, this review summarizes the role of increased ROS in DNA damage and the apoptosis of cancer cells caused by changes in cancer cell metabolism, as well as various anticancer therapies targeting ROS generation, in order to provide references for cancer therapies based on ROS generation.
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Affiliation(s)
- Yongxia Zhao
- National Reference Laboratory of Veterinary Drug Residues (HZAU) and MAO Key Laboratory for Detection of Veterinary Drug Residues, Huazhong Agricultural University, Wuhan 430070, China
| | - Xiaochun Ye
- National Reference Laboratory of Veterinary Drug Residues (HZAU) and MAO Key Laboratory for Detection of Veterinary Drug Residues, Huazhong Agricultural University, Wuhan 430070, China
| | - Zhifeng Xiong
- Department of Animal Nutrition and Feed Science, Huazhong Agricultural University, Wuhan 430070, China
| | - Awais Ihsan
- Department of Biosciences, COMSATS University Islamabad, Sahiwal Campus, Sahiwal 57000, Pakistan
| | - Irma Ares
- Department of Pharmacology and Toxicology, Faculty of Veterinary Medicine, Universidad Complutense de Madrid (UCM), and Research Institute Hospital 12 de Octubre (i+12), 28040 Madrid, Spain
| | - Marta Martínez
- Department of Pharmacology and Toxicology, Faculty of Veterinary Medicine, Universidad Complutense de Madrid (UCM), and Research Institute Hospital 12 de Octubre (i+12), 28040 Madrid, Spain
| | - Bernardo Lopez-Torres
- Department of Pharmacology and Toxicology, Faculty of Veterinary Medicine, Universidad Complutense de Madrid (UCM), and Research Institute Hospital 12 de Octubre (i+12), 28040 Madrid, Spain
| | - María-Rosa Martínez-Larrañaga
- Department of Pharmacology and Toxicology, Faculty of Veterinary Medicine, Universidad Complutense de Madrid (UCM), and Research Institute Hospital 12 de Octubre (i+12), 28040 Madrid, Spain
| | - Arturo Anadón
- Department of Pharmacology and Toxicology, Faculty of Veterinary Medicine, Universidad Complutense de Madrid (UCM), and Research Institute Hospital 12 de Octubre (i+12), 28040 Madrid, Spain
| | - Xu Wang
- National Reference Laboratory of Veterinary Drug Residues (HZAU) and MAO Key Laboratory for Detection of Veterinary Drug Residues, Huazhong Agricultural University, Wuhan 430070, China
- Department of Pharmacology and Toxicology, Faculty of Veterinary Medicine, Universidad Complutense de Madrid (UCM), and Research Institute Hospital 12 de Octubre (i+12), 28040 Madrid, Spain
| | - María-Aránzazu Martínez
- Department of Pharmacology and Toxicology, Faculty of Veterinary Medicine, Universidad Complutense de Madrid (UCM), and Research Institute Hospital 12 de Octubre (i+12), 28040 Madrid, Spain
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20
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Mannherz W, Agarwal S. Thymidine nucleotide metabolism controls human telomere length. Nat Genet 2023; 55:568-580. [PMID: 36959362 PMCID: PMC11000509 DOI: 10.1038/s41588-023-01339-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Accepted: 02/21/2023] [Indexed: 03/25/2023]
Abstract
Telomere length in humans is associated with lifespan and severe diseases, yet the genetic determinants of telomere length remain incompletely defined. Here we performed genome-wide CRISPR-Cas9 functional telomere length screening and identified thymidine (dT) nucleotide metabolism as a limiting factor in human telomere maintenance. Targeted genetic disruption using CRISPR-Cas9 revealed multiple telomere length control points across the thymidine nucleotide metabolism pathway: decreasing dT nucleotide salvage via deletion of the gene encoding nuclear thymidine kinase (TK1) or de novo production by knockout of the thymidylate synthase gene (TYMS) decreased telomere length, whereas inactivation of the deoxynucleoside triphosphohydrolase-encoding gene SAMHD1 lengthened telomeres. Remarkably, supplementation with dT alone drove robust telomere elongation by telomerase in cells, and thymidine triphosphate stimulated telomerase activity in a substrate-independent manner in vitro. In induced pluripotent stem cells derived from patients with genetic telomere biology disorders, dT supplementation or inhibition of SAMHD1 promoted telomere restoration. Our results demonstrate a critical role of thymidine metabolism in controlling human telomerase and telomere length, which may be therapeutically actionable in patients with fatal degenerative diseases.
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Affiliation(s)
- William Mannherz
- Division of Hematology/Oncology and Stem Cell Program, Boston Children's Hospital, Boston, MA, USA
- Pediatric Oncology, Dana-Farber Cancer Institute, Boston, MA, USA
- Biological and Biomedical Sciences Program, Harvard/MIT MD-PhD Program, Harvard Stem Cell Institute, Harvard Initiative for RNA Medicine, and Department of Pediatrics, Harvard Medical School, Boston, MA, USA
| | - Suneet Agarwal
- Division of Hematology/Oncology and Stem Cell Program, Boston Children's Hospital, Boston, MA, USA.
- Pediatric Oncology, Dana-Farber Cancer Institute, Boston, MA, USA.
- Biological and Biomedical Sciences Program, Harvard/MIT MD-PhD Program, Harvard Stem Cell Institute, Harvard Initiative for RNA Medicine, and Department of Pediatrics, Harvard Medical School, Boston, MA, USA.
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21
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Post-Transcriptional and Post-Translational Modifications in Telomerase Biogenesis and Recruitment to Telomeres. Int J Mol Sci 2023; 24:ijms24055027. [PMID: 36902458 PMCID: PMC10003056 DOI: 10.3390/ijms24055027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 03/02/2023] [Accepted: 03/03/2023] [Indexed: 03/08/2023] Open
Abstract
Telomere length is associated with the proliferative potential of cells. Telomerase is an enzyme that elongates telomeres throughout the entire lifespan of an organism in stem cells, germ cells, and cells of constantly renewed tissues. It is activated during cellular division, including regeneration and immune responses. The biogenesis of telomerase components and their assembly and functional localization to the telomere is a complex system regulated at multiple levels, where each step must be tuned to the cellular requirements. Any defect in the function or localization of the components of the telomerase biogenesis and functional system will affect the maintenance of telomere length, which is critical to the processes of regeneration, immune response, embryonic development, and cancer progression. An understanding of the regulatory mechanisms of telomerase biogenesis and activity is necessary for the development of approaches toward manipulating telomerase to influence these processes. The present review focuses on the molecular mechanisms involved in the major steps of telomerase regulation and the role of post-transcriptional and post-translational modifications in telomerase biogenesis and function in yeast and vertebrates.
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22
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Nelson N, Feurstein S, Niaz A, Truong J, Holien JK, Lucas S, Fairfax K, Dickinson J, Bryan TM. Functional genomics for curation of variants in telomere biology disorder associated genes: A systematic review. Genet Med 2023; 25:100354. [PMID: 36496180 DOI: 10.1016/j.gim.2022.11.021] [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: 06/28/2022] [Revised: 11/28/2022] [Accepted: 11/30/2022] [Indexed: 12/12/2022] Open
Abstract
PURPOSE Patients with an underlying telomere biology disorder (TBD) have variable clinical presentations, and they can be challenging to diagnose clinically. A genomic diagnosis for patients presenting with TBD is vital for optimal treatment. Unfortunately, many variants identified during diagnostic testing are variants of uncertain significance. This complicates management decisions, delays treatment, and risks nonuptake of potentially curative therapies. Improved application of functional genomic evidence may reduce variants of uncertain significance classifications. METHODS We systematically searched the literature for published functional assays interrogating TBD gene variants. When possible, established likely benign/benign and likely pathogenic/pathogenic variants were used to estimate the assay sensitivity, specificity, positive predictive value, negative predictive value, and odds of pathogenicity. RESULTS In total, 3131 articles were screened and 151 met inclusion criteria. Sufficient data to enable a PS3/BS3 recommendation were available for TERT variants only. We recommend that PS3 and BS3 can be applied at a moderate and supportive level, respectively. PS3/BS3 application was limited by a lack of assay standardization and limited inclusion of benign variants. CONCLUSION Further assay standardization and assessment of benign variants are required for optimal use of the PS3/BS3 criterion for TBD gene variant classification.
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Affiliation(s)
- Niles Nelson
- The Menzies Institute for Medical Research, College of Health and Medicine, The University of Tasmania, Hobart, Tasmania, Australia; Department of Molecular Medicine, The Royal Hobart Hospital, Hobart, Tasmania, Australia; Department of Molecular Haematology, The Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia.
| | - Simone Feurstein
- Section of Hematology, Oncology, and Rheumatology, Department of Internal Medicine, Heidelberg University Hospital, Heidelberg, Germany
| | - Aram Niaz
- Children's Medical Research Institute, Faculty of Medicine and Health, University of Sydney, Westmead, New South Wales, Australia
| | - Jia Truong
- School of Science, STEM College, RMIT University, Bundoora, Victoria, Australia
| | - Jessica K Holien
- School of Science, STEM College, RMIT University, Bundoora, Victoria, Australia
| | - Sionne Lucas
- The Menzies Institute for Medical Research, College of Health and Medicine, The University of Tasmania, Hobart, Tasmania, Australia
| | - Kirsten Fairfax
- The Menzies Institute for Medical Research, College of Health and Medicine, The University of Tasmania, Hobart, Tasmania, Australia
| | - Joanne Dickinson
- The Menzies Institute for Medical Research, College of Health and Medicine, The University of Tasmania, Hobart, Tasmania, Australia
| | - Tracy M Bryan
- Children's Medical Research Institute, Faculty of Medicine and Health, University of Sydney, Westmead, New South Wales, Australia
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23
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Vulsteke JB, Smith V, Bonroy C, Derua R, Blockmans D, De Haes P, Vanderschueren S, Lenaerts JL, Claeys KG, Wuyts WA, Verschueren P, Vanhandsaeme G, Piette Y, De Langhe E, Bossuyt X. Identification of new telomere- and telomerase-associated autoantigens in systemic sclerosis. J Autoimmun 2023; 135:102988. [PMID: 36634459 DOI: 10.1016/j.jaut.2022.102988] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Accepted: 12/16/2022] [Indexed: 01/12/2023]
Abstract
PURPOSE In up to 20% of patients with systemic sclerosis (SSc) no known autoantibody specificity can be identified. Recently discovered autoantigens, such as telomeric repeat binding factor 1 (TERF1), as well as established autoantigens, like RuvBL1/2, are associated with telomere and telomerase biology. We aimed to identify new telomere- and telomerase-associated autoantigens in patients with SSc without known autoantibody specificity. METHODS Unlabelled protein immunoprecipitation combined with gel-free liquid chromatography-tandem mass spectrometry (IP-MS) was performed with sera of 106 patients with SSc from two tertiary referral centres that had a nuclear pattern on HEp-2 indirect immunofluorescence without previously identified autoantibody. Telomere- or telomerase-associated proteins or protein complexes precipitated by individual sera were identified. Candidate autoantigens were confirmed through immunoprecipitation-western blot (IP-WB). A custom Luminex xMAP assay for 5 proteins was evaluated with sera from persons with SSc (n = 467), other systemic autoimmune rheumatic diseases (n = 923), non-rheumatic disease controls (n = 187) and healthy controls (n = 199). RESULTS Eight telomere- and telomerase-associated autoantigens were identified in a total of 11 index patients, including the THO complex (n = 3, all with interstitial lung disease and two with cardiac involvement), telomeric repeat-binding factor 2 (TERF2, n = 1), homeobox-containing protein 1 (HMBOX1, n = 2), regulator of chromosome condensation 1 (RCC1, n = 1), nucleolar and coiled-body phosphoprotein 1 (NOLC1, n = 1), dyskerin (DKC1, n = 1), probable 28S rRNA (cytosine(4447)-C(5))-methyltransferase (NOP2, n = 1) and nuclear valosin-containing protein-like (NVL, n = 2). A Luminex xMAP assay for THO complex subunit 1 (THOC1), TERF2, NOLC1, NOP2 and NVL revealed high reactivity in all index patients, but also in other patients with SSc and disease controls. However, the reactivity by xMAP assay in these other patients was not confirmed by IP-WB. CONCLUSION IP-MS revealed key telomere- and telomerase-associated proteins and protein complexes as autoantigens in patients with SSc.
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Affiliation(s)
- Jean-Baptiste Vulsteke
- KU Leuven, Department of Development and Regeneration, Skeletal Biology and Engineering Research Center, Leuven, Belgium; Rheumatology, University Hospitals Leuven, Leuven, Belgium
| | - Vanessa Smith
- Ghent University, Department of Internal Medicine, Ghent, Belgium; Unit for Molecular Immunology and Inflammation, VIB Inflammation Research Center (IRC), Ghent, Belgium; Rheumatology, Ghent University Hospital, Ghent, Belgium; European Reference Network on Rare and Complex Connective Tissue and Musculoskeletal Diseases (ERN ReCONNET), Belgium
| | - Carolien Bonroy
- Ghent University, Department of Diagnostic Sciences, Ghent, Belgium; Laboratory Medicine, Ghent University Hospital, Ghent, Belgium
| | - Rita Derua
- KU Leuven, Department of Cellular and Molecular Medicine, Laboratory of Protein Phosphorylation and Proteomics, Leuven, Belgium; KU Leuven, SyBioMa, Leuven, Belgium
| | - Daniel Blockmans
- KU Leuven, Department of Microbiology, Immunology and Transplantation, Laboratory for Clinical Infectious and Inflammatory Disorders, Leuven, Belgium; General Internal Medicine, University Hospitals Leuven, Leuven, Belgium
| | - Petra De Haes
- KU Leuven, Department of Microbiology, Immunology and Transplantation, Leuven, Belgium; Dermatology, University Hospitals Leuven, Leuven, Belgium
| | - Steven Vanderschueren
- KU Leuven, Department of Microbiology, Immunology and Transplantation, Laboratory for Clinical Infectious and Inflammatory Disorders, Leuven, Belgium; General Internal Medicine, University Hospitals Leuven, Leuven, Belgium; European Reference Network on Rare Immunodeficiency, Autoinflammatory and Autoimmune Diseases (ERN RITA), Belgium
| | - Jan L Lenaerts
- Rheumatology, University Hospitals Leuven, Leuven, Belgium
| | - Kristl G Claeys
- KU Leuven, Department of Neurosciences, Laboratory for Muscle Diseases and Neuropathies, Neurology, University Hospitals Leuven, Leuven, Belgium; European Reference Network on Rare Neuromuscular Diseases (ERN EURO-NMD), Belgium
| | - Wim A Wuyts
- KU Leuven, Department of Chronic Diseases and Metabolism, Laboratory of Respiratory Diseases and Thoracic Surgery, Unit for Interstitial Lung Diseases, Respiratory Medicine, University Hospitals Leuven, Leuven, Belgium; European Reference Network on Rare Respiratory Diseases (ERN LUNG), Belgium
| | - Patrick Verschueren
- KU Leuven, Department of Development and Regeneration, Skeletal Biology and Engineering Research Center, Leuven, Belgium; Rheumatology, University Hospitals Leuven, Leuven, Belgium
| | | | - Yves Piette
- Ghent University, Department of Internal Medicine, Ghent, Belgium; Rheumatology, Ghent University Hospital, Ghent, Belgium
| | - Ellen De Langhe
- KU Leuven, Department of Development and Regeneration, Skeletal Biology and Engineering Research Center, Leuven, Belgium; Rheumatology, University Hospitals Leuven, Leuven, Belgium; European Reference Network on Rare and Complex Connective Tissue and Musculoskeletal Diseases (ERN ReCONNET), Belgium; European Reference Network on Rare Immunodeficiency, Autoinflammatory and Autoimmune Diseases (ERN RITA), Belgium
| | - Xavier Bossuyt
- KU Leuven, Department of Microbiology, Immunology and Transplantation, Clinical and Diagnostic Immunology, Leuven, Belgium; Laboratory Medicine, University Hospitals Leuven, Leuven, Belgium.
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Abstract
OPINION STATEMENT Currently approved therapies for myelofibrosis (MF) consist of JAK inhibitors, which produce meaningful improvements in spleen size and symptom burden but do not significantly impact leukemic progression. In addition, many patients develop resistance or intolerance to existing therapies and are left without meaningful therapeutic options. There has been recent rapid development of agents in MF that may be able to fill these unmet needs. Importantly, most treatments currently in clinical development have targets outside the JAK-STAT pathway, including BET, BCL-2/BCL-xL, PI3k, HDM2, PIM-1, SINE, telomerase, LSD1, and CD123. These therapies are being tested in combination with JAK inhibitors in the front-line setting and in patients with a suboptimal response, as well as a single agent after JAK inhibitor failure. This next generation of agents is likely to produce a paradigm shift in MF treatment with a focus on combination treatment targeting multiple areas of MF pathophysiology.
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Affiliation(s)
- Douglas Tremblay
- Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Ruben Mesa
- UT Health San Antonio Cancer Center, San Antonio, TX, USA.
- Mays Cancer Center at UT Health San Antonio MD Anderson, San Antonio, TX, USA.
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25
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Ren Y, Jin L, Zeng H, Busquets R, He G, Deng S, He Q, Khan MR, Deng R, Chi Y. Primer-Engineered Transferase Enzyme for One-Pot and Amplified Detection of Cobalt Pollution and Peptide Remover Screening. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2023; 71:877-883. [PMID: 36563311 DOI: 10.1021/acs.jafc.2c07223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Extensive consumption of cobalt in the chemical field such as for battery materials, alloy, pigments, and dyes has aggravated the pollution of cobalt both in food and the environment, and assays for its on-site monitoring are urgently demanded. Herein, we utilized enzyme dependence on metal cofactors to develop terminal transferase (TdT) as a recognition element, achieving a one-pot sensitive and specific assay for detecting cobalt pollution. We engineered a 3'-OH terminus primer to improve the discrimination capacity of TdT for Co2+ from other bivalent cations. The TdT extension reaction amplified the recognition of Co2+ and yielded a limit of detection of 0.99 μM for Co2+ detection. Then, the TdT-based assay was designed to precisely detect cobalt in food and agricultural soil samples. By end-measurement of fluorescence using a microplate reader, the multiplexing assay enabled the rapid screening of the peptide remover for cobalt pollution. The TdT-based assay can be a promising tool for cobalt pollution monitoring and control.
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Affiliation(s)
- Yao Ren
- College of Biomass Science and Engineering, Healthy Food Evaluation Research Center, Sichuan University, Chengdu, Sichuan 610065, China
| | - Lulu Jin
- College of Biomass Science and Engineering, Healthy Food Evaluation Research Center, Sichuan University, Chengdu, Sichuan 610065, China
| | - Hongling Zeng
- College of Biomass Science and Engineering, Healthy Food Evaluation Research Center, Sichuan University, Chengdu, Sichuan 610065, China
| | - Rosa Busquets
- School of Life Sciences, Pharmacy and Chemistry, Kingston University London, Penrhyn Road, KT1 2EE Kingston Upon Thames, United Kingdom
| | - Guiping He
- College of Biomass Science and Engineering, Healthy Food Evaluation Research Center, Sichuan University, Chengdu, Sichuan 610065, China
| | - Sha Deng
- College of Biomass Science and Engineering, Healthy Food Evaluation Research Center, Sichuan University, Chengdu, Sichuan 610065, China
| | - Qiang He
- College of Biomass Science and Engineering, Healthy Food Evaluation Research Center, Sichuan University, Chengdu, Sichuan 610065, China
| | - Mohammad Rizwan Khan
- Department of Chemistry, College of Science, King Saud University, Riyadh 11451, Saudi Arabia
| | - Ruijie Deng
- College of Biomass Science and Engineering, Healthy Food Evaluation Research Center, Sichuan University, Chengdu, Sichuan 610065, China
| | - Yuanlong Chi
- College of Biomass Science and Engineering, Healthy Food Evaluation Research Center, Sichuan University, Chengdu, Sichuan 610065, China
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26
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Chen Z, Wang Y. A label- and enzyme-free fluorescence assay based on thioflavin T–induced G-quadruplexes for the detection of telomerase activity. JOURNAL OF CHEMICAL RESEARCH 2023. [DOI: 10.1177/17475198221139085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
A label- and enzyme-free fluorescence assay based on thioflavin T–induced G-quadruplexes is developed to sensitively and specifically detect telomerase activity. Thioflavin T has a dual role as an efficient inducer and fluorescent probe, and the incorporation of thioflavin T into the thioflavin T–induced G-quadruplexes results in an intense fluorescence enhancement. In the presence of thioflavin T and K+, G-quadruplexes are formed by elongation of the telomerase substrate primer that is catalyzed by telomerase extracted from cancer cells. Thus, the telomerase activity in cancer cell extracts can be evaluated by measuring the thioflavin T fluorescence. More importantly, thioflavin T can specifically recognize and bind to G-quadruplexes, whereas it cannot recognize single- and double-stranded DNAs, which leads to the thioflavin T–based fluorescence assay exhibiting a reduced background and improved signal-to-noise ratio. As a result, the proposed assay has the linear range from 5 to 200 HeLa cells and the detection limit is 34 HeLa cells, which holds great potential for use in the detection of telomerase activity and the diagnosis of cancer.
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Affiliation(s)
- Zhe Chen
- School of Forensic Medicine, Shanxi Medical University, Jinzhong, P.R. China
- Key Laboratory of Forensic Toxicology of Ministry of Public Security, Jinzhong, P.R. China
| | - Yunxia Wang
- Department of Laboratory Science, Shanxi Medical University, Taiyuan, P.R. China
- The Sixth Hospital of Shanxi Medical University (General Hospital of Tisco), Taiyuan, P.R. China
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27
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Udroiu I, Marinaccio J, Sgura A. Many Functions of Telomerase Components: Certainties, Doubts, and Inconsistencies. Int J Mol Sci 2022; 23:ijms232315189. [PMID: 36499514 PMCID: PMC9736166 DOI: 10.3390/ijms232315189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 11/23/2022] [Accepted: 11/29/2022] [Indexed: 12/12/2022] Open
Abstract
A growing number of studies have evidenced non-telomeric functions of "telomerase". Almost all of them, however, investigated the non-canonical effects of the catalytic subunit TERT, and not the telomerase ribonucleoprotein holoenzyme. These functions mainly comprise signal transduction, gene regulation and the increase of anti-oxidative systems. Although less studied, TERC (the RNA component of telomerase) has also been shown to be involved in gene regulation, as well as other functions. All this has led to the publication of many reviews on the subject, which, however, are often disseminating personal interpretations of experimental studies of other researchers as original proofs. Indeed, while some functions such as gene regulation seem ascertained, especially because mechanistic findings have been provided, other ones remain dubious and/or are contradicted by other direct or indirect evidence (e.g., telomerase activity at double-strand break site, RNA polymerase activity of TERT, translation of TERC, mitochondrion-processed TERC). In a critical study of the primary evidence so far obtained, we show those functions for which there is consensus, those showing contradictory results and those needing confirmation. The resulting picture, together with some usually neglected aspects, seems to indicate a link between TERT and TERC functions and cellular stemness and gives possible directions for future research.
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28
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Mishra R, Haldar S, Biondi S, Bhari VK, Singh G, Bhowmick NA. TGF-β controls stromal telomere length through epigenetic modifications. 3 Biotech 2022; 12:290. [PMID: 36276465 PMCID: PMC9512944 DOI: 10.1007/s13205-022-03346-5] [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: 06/16/2022] [Accepted: 09/01/2022] [Indexed: 11/01/2022] Open
Abstract
Telomere length is primarily controlled by the enzyme telomerase, but being chromatin structures, telomeres undergo epigenetic regulation for their maintenance and function. Altered telomere length among cancer cells combined with shorter telomere length in cancer-associated stromal cells, strongly implicated with progression to prostate cancer metastasis and cancer death and providing a novel target for therapeutics. Transforming growth factor-β (TGF-β) signaling pathways are well-recognized for their role in stromal-epithelial interactions responsible for prostate androgen responsiveness, promoting tumorigenesis. However, the underlying mechanism remains unclear. We sought to establish a role for TGF-β in the regulation of telomere length in mouse and human prostate fibroblast. Polymerase chain reaction (PCR)-based telomere length measuring methods are widely used due to their repeatability and reproducibility. Using real-time RT-PCR-based telomere length measuring method, we identified that TGF-beta regulates telomere length via increased expression of histone methyltransferase, Suv39h1, which in turn affected histone methylation levels at the telomeric ends. Moreover, treatment of DAPT and non-steroidal antiandrogen bicalutamide demonstrated that notch and androgen signaling co-operated with TGF-ß in regulating stromal telomere length. Telomere variation in tumor cells and non-tumor cells within the tumor microenvironment greatly facilitates the clinical assessment of prostate cancer; therefore, understanding stromal telomere length regulation mechanism will hold significant prospects for cancer treatment, diagnosis, and prognosis. Supplementary Information The online version contains supplementary material available at 10.1007/s13205-022-03346-5.
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Affiliation(s)
- Rajeev Mishra
- Department of Life Sciences and Biotechnology, Chhatrapati Shahu Ji Maharaj University, Kalyanpur, Kanpur, UP 208024 India
- Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, CA 90048 USA
| | - Subhash Haldar
- Department of Food and Nutrition, University of Gour Banga, Mokdumpur, West Bengal 732101 India
| | - Shea Biondi
- Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, CA 90048 USA
| | - Vikash Kumar Bhari
- Department of Biosciences, Manipal University Jaipur, Jaipur, Rajasthan 303007 India
| | - Gyanendra Singh
- Toxicology Department, ICMR-National Institute of Occupational Health, Ahmedabad, 380016 India
| | - Neil A Bhowmick
- Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, CA 90048 USA
- Department of Research, Greater Los Angeles Veterans Administration, Los Angeles, CA 90073 USA
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29
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Slusher AL, Kim JJJ, Ribick M, Pollens-Voigt J, Bankhead A, Palmbos PL, Ludlow AT. Intronic Cis-Element DR8 in hTERT Is Bound by Splicing Factor SF3B4 and Regulates hTERT Splicing in Non-Small Cell Lung Cancer. Mol Cancer Res 2022; 20:1574-1588. [PMID: 35852380 PMCID: PMC9532359 DOI: 10.1158/1541-7786.mcr-21-0058] [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: 01/22/2021] [Revised: 11/14/2021] [Accepted: 06/14/2022] [Indexed: 11/16/2022]
Abstract
Splicing of the hTERT gene to produce the full-length (FL) transcript is necessary for telomerase enzyme activity and telomere-dependent cellular immortality in the majority of human tumors, including non-small cell lung cancer (NSCLC) cells. The molecular machinery to splice hTERT to the FL isoform remains mostly unknown. Previously, we reported that an intron 8 cis-element termed "direct repeat 8" (DR8) promotes FL hTERT splicing, telomerase, and telomere length maintenance when bound by NOVA1 and PTBP1 in NSCLC cells. However, some NSCLC cells and patient tumor samples lack NOVA1 expression. This leaves a gap in knowledge about the splicing factors and cis-elements that promote telomerase in the NOVA1-negative context. We report that DR8 regulates FL hTERT splicing in the NOVA1-negative and -positive lung cancer contexts. We identified splicing factor 3b subunit 4 (SF3B4) as an RNA trans-factor whose expression is increased in lung adenocarcinoma (LUAD) tumors compared with adjacent normal tissue and predicts poor LUAD patient survival. In contrast to normal lung epithelial cells, which continued to grow with partial reductions of SF3B4 protein, SF3B4 knockdown reduced hTERT splicing, telomerase activity, telomere length, and cell growth in lung cancer cells. SF3B4 was also demonstrated to bind the DR8 region of hTERT pre-mRNA in both NOVA1-negative and -positive NSCLC cells. These findings provide evidence that DR8 is a critical binding hub for trans-factors to regulate FL hTERT splicing in NSCLC cells. These studies help define mechanisms of gene regulation important to the generation of telomerase activity during carcinogenesis. IMPLICATIONS Manipulation of a core spliceosome protein reduces telomerase/hTERT splicing in lung cancer cells and results in slowed cancer cell growth and cell death, revealing a potential therapeutic strategy.
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Affiliation(s)
- Aaron L. Slusher
- School of Kinesiology, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Jeongjin JJ Kim
- School of Kinesiology, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Mark Ribick
- School of Kinesiology, University of Michigan, Ann Arbor, MI, 48109, USA
| | | | - Armand Bankhead
- Biostatistics Department and School of Public Health, University of Michigan, Ann Arbor, MI, 48109, USA
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Phillip L. Palmbos
- Department of Internal Medicine, University of Michigan Medical Center, Ann Arbor, MI, 48109, USA
| | - Andrew T. Ludlow
- School of Kinesiology, University of Michigan, Ann Arbor, MI, 48109, USA
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30
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Telomeres and Their Neighbors. Genes (Basel) 2022; 13:genes13091663. [PMID: 36140830 PMCID: PMC9498494 DOI: 10.3390/genes13091663] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 09/08/2022] [Accepted: 09/09/2022] [Indexed: 11/21/2022] Open
Abstract
Telomeres are essential structures formed from satellite DNA repeats at the ends of chromosomes in most eukaryotes. Satellite DNA repeat sequences are useful markers for karyotyping, but have a more enigmatic role in the eukaryotic cell. Much work has been done to investigate the structure and arrangement of repetitive DNA elements in classical models with implications for species evolution. Still more is needed until there is a complete picture of the biological function of DNA satellite sequences, particularly when considering non-model organisms. Celebrating Gregor Mendel’s anniversary by going to the roots, this review is designed to inspire and aid new research into telomeres and satellites with a particular focus on non-model organisms and accessible experimental and in silico methods that do not require specialized equipment or expensive materials. We describe how to identify telomere (and satellite) repeats giving many examples of published (and some unpublished) data from these techniques to illustrate the principles behind the experiments. We also present advice on how to perform and analyse such experiments, including details of common pitfalls. Our examples are a selection of recent developments and underexplored areas of research from the past. As a nod to Mendel’s early work, we use many examples from plants and insects, especially as much recent work has expanded beyond the human and yeast models traditional in telomere research. We give a general introduction to the accepted knowledge of telomere and satellite systems and include references to specialized reviews for the interested reader.
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31
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Borges G, Criqui M, Harrington L. Tieing together loose ends: telomere instability in cancer and aging. Mol Oncol 2022; 16:3380-3396. [PMID: 35920280 PMCID: PMC9490142 DOI: 10.1002/1878-0261.13299] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Revised: 07/27/2022] [Accepted: 08/02/2022] [Indexed: 11/29/2022] Open
Abstract
Telomere maintenance is essential for maintaining genome integrity in both normal and cancer cells. Without functional telomeres, chromosomes lose their protective structure and undergo fusion and breakage events that drive further genome instability, including cell arrest or death. One means by which this loss can be overcome in stem cells and cancer cells is via re-addition of G-rich telomeric repeats by the telomerase reverse transcriptase (TERT). During aging of somatic tissues, however, insufficient telomerase expression leads to a proliferative arrest called replicative senescence, which is triggered when telomeres reach a critically short threshold that induces a DNA damage response. Cancer cells express telomerase but do not entirely escape telomere instability as they often possess short telomeres; hence there is often selection for genetic alterations in the TERT promoter that result in increased telomerase expression. In this review, we discuss our current understanding of the consequences of telomere instability in cancer and aging, and outline the opportunities and challenges that lie ahead in exploiting the reliance of cells on telomere maintenance for preserving genome stability.
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Affiliation(s)
- Gustavo Borges
- Molecular Biology Programme, Institute for Research in Immunology and CancerUniversity of MontrealQCCanada
| | - Mélanie Criqui
- Molecular Biology Programme, Institute for Research in Immunology and CancerUniversity of MontrealQCCanada
| | - Lea Harrington
- Molecular Biology Programme, Institute for Research in Immunology and CancerUniversity of MontrealQCCanada
- Departments of Medicine and Biochemistry and Molecular MedicineUniversity of MontrealQCCanada
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32
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Sharaf R, Frampton GM, Albacker LA. Mutations in the TERC template sequence can be incorporated into the telomeres of human tumors. PLoS One 2022; 17:e0272707. [PMID: 36006930 PMCID: PMC9409504 DOI: 10.1371/journal.pone.0272707] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Accepted: 07/25/2022] [Indexed: 11/29/2022] Open
Abstract
Telomerase-mediated lengthening is a mechanism by which some cancer cells avoid senescence-mediated cell cycle arrest due to shortened telomeres. By reverse transcribing an RNA template, encoded by TERC, the enzyme telomerase synthesizes the elongation of telomeric DNA using the 3’ end of the chromosome as a primer. TERC harbors a highly conserved template region consisting of 11 nucleotides spanning hg19 coordinates chr3:169482793–169482803. In human cell lines, when TERC was mutated to alter its template region, telomerase generated the predicted mutant telomeric repeats. However, it is unknown if this can occur in human clinical samples. Here, we report on the rare occurrence of two tumor samples where TERC template mutations were reflected in telomeric repeats.
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Affiliation(s)
- Radwa Sharaf
- Foundation Medicine Inc., Cambridge, MA, United States of America
| | | | - Lee A. Albacker
- Foundation Medicine Inc., Cambridge, MA, United States of America
- * E-mail:
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33
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Impact of Host Telomere Length on HHV-6 Integration. Viruses 2022; 14:v14091864. [PMID: 36146670 PMCID: PMC9505050 DOI: 10.3390/v14091864] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 08/15/2022] [Accepted: 08/21/2022] [Indexed: 12/04/2022] Open
Abstract
Human herpesvirus 6A and 6B are two closely related viruses that infect almost all humans. In contrast to most herpesviruses, HHV-6A/B can integrate their genomes into the telomeres during the infection process. Both viruses can also integrate in germ cells and subsequently be inherited in children. How HHV-6A/B integrate into host telomeres and the consequences of this remain a subject of active research. Here, we developed a method to measure telomere length by quantitative fluorescence in situ hybridization, confocal microscopy, and computational processing. This method was validated using a panel of HeLa cells having short or long telomeres. These cell lines were infected with HHV-6A, revealing that the virus could efficiently integrate into telomeres independent of their length. Furthermore, we assessed the telomere lengths after HHV-6A integration and found that the virus-containing telomeres display a variety of lengths, suggesting that either telomere length is restored after integration or telomeres are not shortened by integration. Our results highlight new aspects of HHV-6A/B biology and the role of telomere length on virus integration.
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34
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The Role of Hsp90-R2TP in Macromolecular Complex Assembly and Stabilization. Biomolecules 2022; 12:biom12081045. [PMID: 36008939 PMCID: PMC9406135 DOI: 10.3390/biom12081045] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 07/19/2022] [Accepted: 07/25/2022] [Indexed: 01/27/2023] Open
Abstract
Hsp90 is a ubiquitous molecular chaperone involved in many cell signaling pathways, and its interactions with specific chaperones and cochaperones determines which client proteins to fold. Hsp90 has been shown to be involved in the promotion and maintenance of proper protein complex assembly either alone or in association with other chaperones such as the R2TP chaperone complex. Hsp90-R2TP acts through several mechanisms, such as by controlling the transcription of protein complex subunits, stabilizing protein subcomplexes before their incorporation into the entire complex, and by recruiting adaptors that facilitate complex assembly. Despite its many roles in protein complex assembly, detailed mechanisms of how Hsp90-R2TP assembles protein complexes have yet to be determined, with most findings restricted to proteomic analyses and in vitro interactions. This review will discuss our current understanding of the function of Hsp90-R2TP in the assembly, stabilization, and activity of the following seven classes of protein complexes: L7Ae snoRNPs, spliceosome snRNPs, RNA polymerases, PIKKs, MRN, TSC, and axonemal dynein arms.
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35
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Zaug AJ, Goodrich KJ, Song JJ, Sullivan AE, Cech TR. Reconstitution of a telomeric replicon organized by CST. Nature 2022; 608:819-825. [PMID: 35831508 PMCID: PMC9402439 DOI: 10.1038/s41586-022-04930-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Accepted: 06/06/2022] [Indexed: 11/20/2022]
Abstract
Telomeres, the natural ends of linear chromosomes, comprise repeat-sequence DNA and associated proteins1. Replication of telomeres allows continued proliferation of human stem cells and immortality of cancer cells2. This replication requires telomerase3 extension of the single-stranded DNA (ssDNA) of the telomeric G-strand ((TTAGGG)n); the synthesis of the complementary C-strand ((CCCTAA)n) is much less well characterized. The CST (CTC1–STN1–TEN1) protein complex, a DNA polymerase α-primase accessory factor4,5, is known to be required for telomere replication in vivo6–9, and the molecular analysis presented here reveals key features of its mechanism. We find that human CST uses its ssDNA-binding activity to specify the origins for telomeric C-strand synthesis by bound Polα-primase. CST-organized DNA polymerization can copy a telomeric DNA template that folds into G-quadruplex structures, but the challenges presented by this template probably contribute to telomere replication problems observed in vivo. Combining telomerase, a short telomeric ssDNA primer and CST–Polα–primase gives complete telomeric DNA replication, resulting in the same sort of ssDNA 3′ overhang found naturally on human telomeres. We conclude that the CST complex not only terminates telomerase extension10,11 and recruits Polα–primase to telomeric ssDNA4,12,13 but also orchestrates C-strand synthesis. Because replication of the telomere has features distinct from replication of the rest of the genome, targeting telomere-replication components including CST holds promise for cancer therapeutics. The Polα–primase-associated CST complex organizes telomeric C-strand DNA synthesis, and, in combination with telomerase, it carries out complete replication of the single-stranded DNA overhang found at human telomeres.
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Affiliation(s)
- Arthur J Zaug
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO, USA.,BioFrontiers Institute, University of Colorado Boulder, Boulder, CO, USA.,Howard Hughes Medical Institute, University of Colorado Boulder, Boulder, CO, USA
| | - Karen J Goodrich
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO, USA.,BioFrontiers Institute, University of Colorado Boulder, Boulder, CO, USA.,Howard Hughes Medical Institute, University of Colorado Boulder, Boulder, CO, USA
| | - Jessica J Song
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO, USA
| | - Ashley E Sullivan
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO, USA
| | - Thomas R Cech
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO, USA. .,BioFrontiers Institute, University of Colorado Boulder, Boulder, CO, USA. .,Howard Hughes Medical Institute, University of Colorado Boulder, Boulder, CO, USA.
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Rubtsova M, Dontsova O. How Structural Features Define Biogenesis and Function of Human Telomerase RNA Primary Transcript. Biomedicines 2022; 10:biomedicines10071650. [PMID: 35884955 PMCID: PMC9313293 DOI: 10.3390/biomedicines10071650] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 07/06/2022] [Accepted: 07/06/2022] [Indexed: 11/16/2022] Open
Abstract
Telomerase RNA has been uncovered as a component of the telomerase enzyme, which acts as a reverse transcriptase and maintains the length of telomeres in proliferated eukaryotic cells. Telomerase RNA is considered to have major functions as a template for telomeric repeat synthesis and as a structural scaffold for telomerase. However, investigations of its biogenesis and turnover, as well as structural data, have provided evidence of functions of telomerase RNA that are not associated with telomerase activity. The primary transcript produced from the human telomerase RNA gene encodes for the hTERP protein, which presents regulatory functions related to autophagy, cellular proliferation, and metabolism. This review focuses on the specific features relating to the biogenesis and structure of human telomerase RNA that support the existence of an isoform suitable for functioning as an mRNA. We believe that further investigation into human telomerase RNA biogenesis mechanisms will provide more levels for manipulating cellular homeostasis, survival, and transformation mechanisms, and may contribute to a deeper understanding of the mechanisms of aging.
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Affiliation(s)
- Maria Rubtsova
- Department of Chemistry, A.N. Belozersky Institute of Physico Chemical Biology, Lomonosov Moscow State University, 119991 Moscow, Russia;
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry of the Russian Academy of Sciences, 117997 Moscow, Russia
- Correspondence:
| | - Olga Dontsova
- Department of Chemistry, A.N. Belozersky Institute of Physico Chemical Biology, Lomonosov Moscow State University, 119991 Moscow, Russia;
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry of the Russian Academy of Sciences, 117997 Moscow, Russia
- Center of Life Sciences, Skolkovo Institute of Science and Technology, Skolkovo, 121205 Moscow, Russia
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Ebata H, Loo TM, Takahashi A. Telomere Maintenance and the cGAS-STING Pathway in Cancer. Cells 2022; 11:1958. [PMID: 35741087 PMCID: PMC9221635 DOI: 10.3390/cells11121958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2022] [Revised: 06/15/2022] [Accepted: 06/16/2022] [Indexed: 11/17/2022] Open
Abstract
Cancer cells exhibit the unique characteristics of high proliferation and aberrant DNA damage response, which prevents cancer therapy from effectively eliminating them. The machinery required for telomere maintenance, such as telomerase and the alternative lengthening of telomeres (ALT), enables cancer cells to proliferate indefinitely. In addition, the molecules in this system are involved in noncanonical pro-tumorigenic functions. Of these, the function of the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway, which contains telomere-related molecules, is a well-known contributor to the tumor microenvironment (TME). This review summarizes the current knowledge of the role of telomerase and ALT in cancer regulation, with emphasis on their noncanonical roles beyond telomere maintenance. The components of the cGAS-STING pathway are summarized with respect to intercell communication in the TME. Elucidating the underlying functional connection between telomere-related molecules and TME regulation is important for the development of cancer therapeutics that target cancer-specific pathways in different contexts. Finally, strategies for designing new cancer therapies that target cancer cells and the TME are discussed.
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Affiliation(s)
- Hiroshi Ebata
- Department of Biological Sciences, Faculty of Science, The University of Tokyo, Tokyo 113-0033, Japan;
- Project for Cellular Senescence, Cancer Institute, Japanese Foundation for Cancer Research, Tokyo 135-8550, Japan;
| | - Tze Mun Loo
- Project for Cellular Senescence, Cancer Institute, Japanese Foundation for Cancer Research, Tokyo 135-8550, Japan;
| | - Akiko Takahashi
- Project for Cellular Senescence, Cancer Institute, Japanese Foundation for Cancer Research, Tokyo 135-8550, Japan;
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Paul T, Opresko PL, Ha T, Myong S. Vectorial folding of telomere overhang promotes higher accessibility. Nucleic Acids Res 2022; 50:6271-6283. [PMID: 35687089 PMCID: PMC9226509 DOI: 10.1093/nar/gkac401] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 04/20/2022] [Accepted: 06/08/2022] [Indexed: 11/13/2022] Open
Abstract
Human telomere overhang composed of tandem repeats of TTAGGG folds into G-quadruplex (G4). Unlike in an experimental setting in the test tube in which the entire length is allowed to fold at once, inside the cell, the overhang is expected to fold as it is synthesized directionally (5' to 3') and released segmentally by a specialized enzyme, the telomerase. To mimic such vectorial G4 folding process, we employed a superhelicase, Rep-X which can unwind DNA to release the TTAGGG repeats in 5' to 3' direction. We demonstrate that the folded conformation achieved by the refolding of full sequence is significantly different from that of the vectorial folding for two to eight TTAGGG repeats. Strikingly, the vectorially folded state leads to a remarkably higher accessibility to complementary C-rich strand and the telomere binding protein POT1, reflecting a less stably folded state resulting from the vectorial folding. Importantly, our study points to an inherent difference between the co-polymerizing and post-polymerized folding of telomere overhang that can impact telomere architecture and downstream processes.
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Affiliation(s)
- Tapas Paul
- Department of Biophysics, Johns Hopkins University, Baltimore, MD21218, USA
| | - Patricia L Opresko
- Department of Environmental and Occupational Health, University of Pittsburgh Graduate School of Public Health, and UPMC Hillman Cancer Center, Pittsburgh, PA15213, USA
| | - Taekjip Ha
- Department of Biophysics, Johns Hopkins University, Baltimore, MD21218, USA.,Physics Frontier Center (Center for Physics of Living Cells), University of Illinois, 1110 W. Green St., Urbana, IL 61801, USA.,Howard Hughes Medical Institute, Johns Hopkins University, Baltimore, MD, USA
| | - Sua Myong
- Department of Biophysics, Johns Hopkins University, Baltimore, MD21218, USA.,Physics Frontier Center (Center for Physics of Living Cells), University of Illinois, 1110 W. Green St., Urbana, IL 61801, USA
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Song Y, Ma Z, Zhang W. Manipulation of a Single Polymer Chain: From the Nanomechanical Properties to Dynamic Structure Evolution. Macromolecules 2022. [DOI: 10.1021/acs.macromol.2c00076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Yu Song
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun 130012, P. R. China
| | - Ziwen Ma
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun 130012, P. R. China
| | - Wenke Zhang
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun 130012, P. R. China
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Slusher AL, Kim JJJ, Ribick M, Ludlow AT. Acute Exercise Regulates hTERT Gene Expression and Alternative Splicing in the hTERT-BAC Transgenic Mouse Model. Med Sci Sports Exerc 2022; 54:931-943. [PMID: 35135999 PMCID: PMC9117413 DOI: 10.1249/mss.0000000000002868] [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] [Indexed: 11/21/2022]
Abstract
INTRODUCTION Aerobic exercise maintains telomere length through increased human telomerase reverse transcriptase (hTERT) expression and telomerase enzyme activity. The impact of acute exercise on hTERT alternative splicing (AS) is unknown. PURPOSE This study aimed to examine hTERT AS in response to acute treadmill running. METHODS A bacterial artificial chromosome mouse model containing the 54-kilobase hTERT gene locus inserted into its genome (hTERT-BAC) was utilized. The gastrocnemius, left ventricle, and brain were excised before (Pre), upon cessation (Post), and during recovery (1, 24, 48, and 72 h; n = 5/time point) from treadmill running (30 min at 60% maximum speed). Full-length (FL) hTERT and the "minus beta" (-β) AS variant (skips exons 7 and 8 and does not code for active telomerase) were measured by gel-based and droplet digital reverse transcription-polymerase chain reaction methods. SF3B4 and SRSF2 protein expression were measured by Western blotting. RESULTS Compared with Pre, FL hTERT increased at Post before decreasing during recovery in the gastrocnemius (48 and 72 h; P ≤ 0.001) and left ventricle (24 h; P = 0.004). The percentage of FL hTERT in the gastrocnemius also increased during recovery (1 and 72 h; P ≤ 0.017), whereas a decrease was observed in the left ventricle (1, 24, and 48 h; P ≤ 0.041). hTERT decreased in the brain (48 h), whereas FL hTERT percentage remained unaltered. SF3B4 protein expression decreased throughout recovery in the gastrocnemius and tended to be associated with FL hTERT (r = -0.348, P = 0.075) and -β in opposite directions (r = 0.345, P = 0.067). CONCLUSIONS Endurance exercise increased hTERT gene expression, and altered FL hTERT splicing in contractile tissues and may maintain telomere length necessary to improve the function and health of the organism.
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Affiliation(s)
| | - Jeongjin JJ Kim
- School of Kinesiology, University of Michigan, Ann Arbor, MI
| | - Mark Ribick
- School of Kinesiology, University of Michigan, Ann Arbor, MI
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Knockdown of the stem cell marker Musashi-1 inhibits endometrial cancer growth and sensitizes cells to radiation. Stem Cell Res Ther 2022; 13:212. [PMID: 35619161 PMCID: PMC9137084 DOI: 10.1186/s13287-022-02891-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Accepted: 04/02/2022] [Indexed: 11/22/2022] Open
Abstract
Background Endometrial carcinoma is the most common gynecological cancer in Europe. Musashi-1 is known to be a key regulator of endometrial cancer stem cells and a negative prognostic marker. In the present study, we aimed to understand growth and gene expression patterns in endometrial carcinoma after Musashi-1 knockdown in vitro and in vivo. Changes in therapeutic resistance were also assessed.
Methods First, we performed analyses to understand Musashi-1 expression patterns using The Cancer Genome Atlas database. We then proceeded to assess effects of small interfering RNA-based Musashi-1 targeting in two endometrial carcinoma cell lines, Ishikawa and KLE. After quantifying baseline changes in cell metabolism, we used MTT tests to assess chemotherapy effects and colony formation assays to understand changes in radioresistance. For mechanistic study, we used quantitative polymerase chain reaction (qPCR) and western blotting of key Musashi-1 target genes and compared results to primary tissue database studies. Finally, xenograft experiments in a mouse model helped understand in vivo effects of Musashi-1 knockdown. Results Musashi-1 is aberrantly expressed in primary tumor tissues. In vitro, silencing of Musashi-1 resulted in a strong decline in cell proliferation and radioresistance, while chemoresistance remained unchanged. Loss of Musashi-1 led to downregulation of telomerase, DNA-dependent protein kinase, the Notch pathway and overexpression of cyclin-dependent kinase inhibitor p21, the latter of which we identified as a key mediator of Msi-1 knockdown-related anti-proliferative signaling. In vivo, the anti-proliferative effect was confirmed, with Msi-1 knockdown tumors being about 40% reduced in size. Conclusions Musashi-1 knockdown resulted in a strong decrease in endometrial cancer proliferation and a loss of radioresistance, suggesting therapeutic potential. Supplementary Information The online version contains supplementary material available at 10.1186/s13287-022-02891-3.
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Liu X, Zhang L, Lu L, Jiang W, Zhang N. A primer extension activating 3D DNAzyme walker for in situ imaging and sensitive detection of telomerase activity. Analyst 2022; 147:1968-1975. [PMID: 35416808 DOI: 10.1039/d2an00142j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Acquiring information on telomerase activity at multiple levels contributes to a better understanding of its role in various physiological and pathological processes. Herein, a primer extension activating 3D DNAzyme walker is developed for in situ imaging and sensitive detection of telomerase activity. This walker is constructed via co-modifying specially designed hairpin structured walking strands and track strands on a gold nanoparticle (AuNP). The walking strand contains a pre-blocked DNAzyme sequence and a telomerase primer hybridized to its root. The track strand embeds at an RNA cleavage site and is labeled with the FAM group. After this walker is taken up by cells, the telomerase primer is extended under the action of endogenous telomerase to liberate DNAzyme. The liberated DNAzyme cuts track strands in the presence of the cofactor Mn2+ to drive the walker's processive operation, resulting in an enhanced fluorescence recovery of the AuNP-quenched FAM fluorophore. In situ imaging of telomerase activity in three different cell lines (MCF-7 cells, HeLa cells and HL-7702 cells) was well implemented. The discrimination of cancer cells from normal cells and the screening of telomerase inhibitors have been achieved. The sensitive detection of telomerase activity in HeLa cell lysate has also been realized with a detection limit of 10 cells. This walker performed a new approach for monitoring telomerase activity from different levels, providing a potential tool for clinical diagnosis, prognostic evaluation and drug screening.
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Affiliation(s)
- Xiaoting Liu
- Research Center of Basic Medicine, Breast Center, Jinan Central Hospital, Cheeloo College of Medicine, Shandong University, 250013, Jinan, PR China. .,School of Chemistry and Chemical Engineering, Shandong University, 250100, Jinan, PR China
| | - Liyan Zhang
- School of Chemistry and Chemical Engineering, Shandong University, 250100, Jinan, PR China
| | - Ling Lu
- Research Center of Basic Medicine, Breast Center, Jinan Central Hospital, Cheeloo College of Medicine, Shandong University, 250013, Jinan, PR China.
| | - Wei Jiang
- School of Chemistry and Chemical Engineering, Shandong University, 250100, Jinan, PR China
| | - Nan Zhang
- Research Center of Basic Medicine, Breast Center, Jinan Central Hospital, Cheeloo College of Medicine, Shandong University, 250013, Jinan, PR China.
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43
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Functional interaction between compound heterozygous TERT mutations causes severe telomere biology disorder. Blood Adv 2022; 6:3779-3791. [PMID: 35477117 DOI: 10.1182/bloodadvances.2022007029] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Accepted: 04/07/2022] [Indexed: 11/20/2022] Open
Abstract
Telomere biology disorders (TBDs) are a spectrum of multisystem inherited disorders characterized by bone marrow failure, resulting from mutations in genes encoding telomerase or other proteins involved in maintaining telomere length and integrity. Pathogenicity of variants in these genes can be hard to evaluate, since TBD mutations show highly variable penetrance and genetic anticipation due to inheritance of shorter telomeres with each generation. Thus, detailed functional analysis of newly identified variants is often essential. Here we describe a patient with compound heterozygous variants in the TERT gene, which encodes the catalytic subunit of telomerase, hTERT; this patient has the extremely severe Hoyeraal-Hreidarsson form of TBD, although his heterozygous parents are clinically unaffected. Molecular dynamic modeling and detailed biochemical analyses demonstrate that 1 allele (L557P) affects association of hTERT with its cognate RNA component hTR, while the other (K1050E) affects the binding of telomerase to its DNA substrate and enzyme processivity. Unexpectedly, the data demonstrate a functional interaction between the proteins encoded by the 2 alleles, with WT hTERT able to rescue the effect of K1050E on processivity, whereas L557P hTERT cannot. These data contribute to the mechanistic understanding of telomerase, indicating that RNA binding in 1 hTERT molecule affects the processivity of telomere addition by the other molecule. This work emphasizes the importance of functional characterization of TERT variants to reach a definitive molecular diagnosis for TBD patients, and in particular it illustrates the importance of analyzing the effects of compound heterozygous variants in combination to reveal interallelic effects.
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Tazawa H, Shigeyasu K, Noma K, Kagawa S, Sakurai F, Mizuguchi H, Kobayashi H, Imamura T, Fujiwara T. Tumor‐targeted fluorescence labeling systems for cancer diagnosis and treatment. Cancer Sci 2022; 113:1919-1929. [PMID: 35398956 PMCID: PMC9207361 DOI: 10.1111/cas.15369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Revised: 03/25/2022] [Accepted: 04/02/2022] [Indexed: 11/28/2022] Open
Abstract
Conventional imaging techniques are available for clinical identification of tumor sites. However, detecting metastatic tumor cells that are spreading from primary tumor sites using conventional imaging techniques remains difficult. In contrast, fluorescence‐based labeling systems are useful tools for detecting tumor cells at the single‐cell level in cancer research. The ability to detect fluorescent‐labeled tumor cells enables investigations of the biodistribution of tumor cells for the diagnosis and treatment of cancer. For example, the presence of fluorescent tumor cells in the peripheral blood of cancer patients is a predictive biomarker for early diagnosis of distant metastasis. The elimination of fluorescent tumor cells without damaging normal tissues is ideal for minimally invasive treatment of cancer. To capture fluorescent tumor cells within normal tissues, however, tumor‐specific activated target molecules are needed. This review focuses on recent advances in tumor‐targeted fluorescence labeling systems, in which indirect reporter labeling using tumor‐specific promoters is applied to fluorescence labeling of tumor cells for the diagnosis and treatment of cancer. Telomerase promoter‐dependent fluorescence labeling using replication‐competent viral vectors produces fluorescent proteins that can be used to detect and eliminate telomerase‐positive tumor cells. Tissue‐specific promoter‐dependent fluorescence labeling enables identification of specific tumor cells. Vimentin promoter‐dependent fluorescence labeling is a useful tool for identifying tumor cells that undergo epithelial–mesenchymal transition (EMT). The evaluation of tumor cells undergoing EMT is important for accurately assessing metastatic potential. Thus, tumor‐targeted fluorescence labeling systems represent novel platforms that enable the capture of tumor cells for the diagnosis and treatment of cancer.
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Affiliation(s)
- Hiroshi Tazawa
- Department of Gastroenterological Surgery Okayama University Graduate School of Medicine Dentistry and Pharmaceutical Sciences Okayama Japan
- Center for Innovative Clinical Medicine Okayama University Hospital Okayama Japan
| | - Kunitoshi Shigeyasu
- Department of Gastroenterological Surgery Okayama University Graduate School of Medicine Dentistry and Pharmaceutical Sciences Okayama Japan
| | - Kazuhiro Noma
- Department of Gastroenterological Surgery Okayama University Graduate School of Medicine Dentistry and Pharmaceutical Sciences Okayama Japan
| | - Shunsuke Kagawa
- Department of Gastroenterological Surgery Okayama University Graduate School of Medicine Dentistry and Pharmaceutical Sciences Okayama Japan
- Minimally Invasive Therapy Center Okayama University Hospital Okayama Japan
| | - Fuminori Sakurai
- Laboratory of Biochemistry and Molecular Biology Graduate School of Pharmaceutical Sciences Osaka University Osaka Japan
| | - Hiroyuki Mizuguchi
- Laboratory of Biochemistry and Molecular Biology Graduate School of Pharmaceutical Sciences Osaka University Osaka Japan
| | - Hisataka Kobayashi
- Molecular Imaging Branch Center for Cancer Research National Cancer Institute National Institutes of Health Bethesda MD USA
| | - Takeshi Imamura
- Department of Molecular Medicine for Pathogenesis Ehime University Graduate School of Medicine Ehime Japan
| | - Toshiyoshi Fujiwara
- Department of Gastroenterological Surgery Okayama University Graduate School of Medicine Dentistry and Pharmaceutical Sciences Okayama Japan
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Wu S, Ge Y, Lin K, Liu Q, Zhou H, Hu Q, Zhao Y, He W, Ju Z. Telomerase RNA TERC and the PI3K-AKT pathway form a positive feedback loop to regulate cell proliferation independent of telomerase activity. Nucleic Acids Res 2022; 50:3764-3776. [PMID: 35323972 PMCID: PMC9023280 DOI: 10.1093/nar/gkac179] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 02/11/2022] [Accepted: 03/16/2022] [Indexed: 02/06/2023] Open
Abstract
The core catalytic unit of telomerase comprises telomerase reverse transcriptase (TERT) and telomerase RNA (TERC). Unlike TERT, which is predominantly expressed in cancer and stem cells, TERC is ubiquitously expressed in normal somatic cells without telomerase activity. However, the functions of TERC in these telomerase-negative cells remain elusive. Here, we reported positive feedback regulation between TERC and the PI3K-AKT pathway that controlled cell proliferation independent of telomerase activity in human fibroblasts. Mechanistically, we revealed that TERC activated the transcription of target genes from the PI3K-AKT pathway, such as PDPK1, by targeting their promoters. Overexpression of PDPK1 partially rescued the deficiency of AKT activation caused by TERC depletion. Furthermore, we found that FOXO1, a transcription factor negatively regulated by the PI3K-AKT pathway, bound to TERC promoter and suppressed its expression. Intriguingly, TERC-induced activation of the PI3K-AKT pathway also played a critical role in the proliferation of activated CD4+ T cells. Collectively, our findings identify a novel function of TERC that regulates the PI3K-AKT pathway via positive feedback to elevate cell proliferation independent of telomerase activity and provide a potential strategy to promote CD4+ T cells expansion that is responsible for enhancing adaptive immune reactions to defend against pathogens and tumor cells.
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Affiliation(s)
- Shu Wu
- Key Laboratory of Regenerative Medicine of Ministry of Education, Institute of Aging and Regenerative Medicine, Jinan University, Guangzhou 510632, China
| | - Yuanlong Ge
- Key Laboratory of Regenerative Medicine of Ministry of Education, Institute of Aging and Regenerative Medicine, Jinan University, Guangzhou 510632, China.,GCH Regenerative Medicine Group-Jinan University Joint Research and Development Center, Jinan University, Guangzhou 510632, China
| | - Kaixuan Lin
- Department of Genetics and Yale Stem Cell Center, Yale School of Medicine, New Haven, CT 06520, USA
| | - Qianqian Liu
- First Affiliated Hospital, School of Medicine, Jinan University, Guangzhou 510632, China
| | - Haoxian Zhou
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Qian Hu
- Key Laboratory of Regenerative Medicine of Ministry of Education, Institute of Aging and Regenerative Medicine, Jinan University, Guangzhou 510632, China
| | - Yong Zhao
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Weifeng He
- Institute of Burn Research, Southwest Hospital, State Key Laboratory of Trauma, Burn and Combined Injury, Chongqing Key Laboratory for Disease Proteomics, Army Military Medical University, Chongqing 400038, China
| | - Zhenyu Ju
- Key Laboratory of Regenerative Medicine of Ministry of Education, Institute of Aging and Regenerative Medicine, Jinan University, Guangzhou 510632, China
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Sharaf R, Montesion M, Hopkins JF, Song J, Frampton GM, Albacker LA. A pan-cancer landscape of telomeric content shows that RAD21 and HGF alterations are associated with longer telomeres. Genome Med 2022; 14:25. [PMID: 35227290 PMCID: PMC8883689 DOI: 10.1186/s13073-022-01029-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Accepted: 02/11/2022] [Indexed: 01/02/2023] Open
Abstract
Background Cancer cells can proliferate indefinitely through telomere maintenance mechanisms. These mechanisms include telomerase-dependent elongation, mediated by TERT activation, and alternative lengthening of telomeres (ALT), linked to loss of ATRX or DAXX. Methods We analyzed the telomeric content of 89,959 tumor samples within the Foundation Medicine dataset and investigated the genomic determinants of high telomeric content, linking them to clinical outcomes, when available. Results Telomeric content varied widely by disease type with leiomyosarcoma having the highest and Merkel cell carcinoma having the lowest telomeric content. In agreement with previous studies, telomeric content was significantly higher in samples with alterations in TERC, ATRX, and DAXX. We further identified that amplifications in two genes, RAD21 and HGF, were enriched in samples with high telomeric content, which was confirmed using the PCAWG/ICGC dataset. We identified the minimal amplified region associated with high telomeric content for RAD21 (8q23.1–8q24.12), which excludes MYC, and for HGF (7q21.11). Our results demonstrated that RAD21 and HGF exerted an additive telomere lengthening effect on samples with existing alterations in canonical genes previously associated with telomere elongation. Furthermore, patients with breast cancer who harbor RAD21 alterations had poor median overall survival and trended towards higher levels of Ki-67 staining. Conclusions This study highlights the importance of the role played by RAD21 (8q23.1–8q24.12) and HGF (7q21.11) in the lengthening of telomeres, supporting unlimited replication in tumors. These findings open avenues for work aimed at targeting this crucial pathway in tumorigenesis. Supplementary Information The online version contains supplementary material available at 10.1186/s13073-022-01029-7.
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Affiliation(s)
- Radwa Sharaf
- Foundation Medicine Inc, 150 Second Street, Cambridge, MA, 02141, USA
| | - Meagan Montesion
- Foundation Medicine Inc, 150 Second Street, Cambridge, MA, 02141, USA
| | - Julia F Hopkins
- Foundation Medicine Inc, 150 Second Street, Cambridge, MA, 02141, USA
| | - Jiarong Song
- Foundation Medicine Inc, 150 Second Street, Cambridge, MA, 02141, USA
| | | | - Lee A Albacker
- Foundation Medicine Inc, 150 Second Street, Cambridge, MA, 02141, USA.
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47
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Novel treatments for myelofibrosis: beyond JAK inhibitors. Int J Hematol 2022; 115:645-658. [PMID: 35182376 DOI: 10.1007/s12185-022-03299-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Revised: 01/24/2022] [Accepted: 01/24/2022] [Indexed: 10/19/2022]
Abstract
Myelofibrosis is a chronic hematologic malignancy characterized by constitutional symptoms, bone marrow fibrosis, extramedullary hematopoiesis resulting in splenomegaly and a propensity toward leukemic progression. Given the central role of the JAK-STAT pathway in the pathobiology of myelofibrosis, JAK inhibitors are the mainstay of current pharmacologic management. Although these therapies have produced meaningful improvements in splenomegaly and symptom burden, JAK inhibitors do not significantly impact disease progression. In addition, many patients are ineligible because of disease-related cytopenias, which are exacerbated by JAK inhibitors. Therefore, there is a continued effort to identify targets outside the JAK-STAT pathway. In this review, we discuss novel therapies in development for myelofibrosis. We focus on the preclinical rationale, efficacy and safety data for non-JAK inhibitor therapies that have published or presented clinical data. Specifically, we discuss agents that target epigenetic modification (pelabresib, bomedemstat), apoptosis (navitoclax, navtemdalin), signaling pathways (parsaclisib), bone marrow fibrosis (AVID200, PRM-151), in addition to other targets including telomerase (imetelstat), selective inhibitor of nuclear transport (selinexor), CD123 (tagraxofusp) and erythroid maturation (luspatercept). We end by providing commentary on the ongoing and future therapeutic development in myelofibrosis.
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Ruiz A, Flores-Gonzalez J, Buendia-Roldan I, Chavez-Galan L. Telomere Shortening and Its Association with Cell Dysfunction in Lung Diseases. Int J Mol Sci 2021; 23:425. [PMID: 35008850 PMCID: PMC8745057 DOI: 10.3390/ijms23010425] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 12/22/2021] [Accepted: 12/29/2021] [Indexed: 01/10/2023] Open
Abstract
Telomeres are localized at the end of chromosomes to provide genome stability; however, the telomere length tends to be shortened with each cell division inducing a progressive telomere shortening (TS). In addition to age, other factors, such as exposure to pollutants, diet, stress, and disruptions in the shelterin protein complex or genes associated with telomerase induce TS. This phenomenon favors cellular senescence and genotoxic stress, which increases the risk of the development and progression of lung diseases such as idiopathic pulmonary fibrosis, chronic obstructive pulmonary disease, SARS-CoV-2 infection, and lung cancer. In an infectious environment, immune cells that exhibit TS are associated with severe lymphopenia and death, whereas in a noninfectious context, naïve T cells that exhibit TS are related to cancer progression and enhanced inflammatory processes. In this review, we discuss how TS modifies the function of the immune system cells, making them inefficient in maintaining homeostasis in the lung. Finally, we discuss the advances in drug and gene therapy for lung diseases where TS could be used as a target for future treatments.
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Affiliation(s)
| | | | | | - Leslie Chavez-Galan
- Instituto Nacional de Enfermedades Respiratorias Ismael Cosío Villegas, Mexico City 14080, Mexico; (A.R.); (J.F.-G.); (I.B.-R.)
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Tremblay D, Hoffman R. Emerging drugs for the treatment of myelofibrosis: phase II & III clinical trials. Expert Opin Emerg Drugs 2021; 26:351-362. [PMID: 34875179 DOI: 10.1080/14728214.2021.2015320] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
INTRODUCTION Myelofibrosis is a clonal hematologic malignancy with clinical manifestations that include cytopenias, debilitating constitutional symptoms, splenomegaly, bone marrow fibrosis and a propensity toward leukemic progression. While allogeneic hematopoietic stem cell transplantation can be curative, this therapy is not available for the majority of patients. Ruxolitinib and fedratinib are approved JAK2 inhibitors that have produced meaningful benefits in terms of spleen reduction and symptom improvement, but there remain several unmet needs. AREAS COVERED We discuss novel therapies based upon published data from phase II or III clinical trials. Specifically, we cover novel JAK inhibitors (momelotinib and pacritinib), and agents that target bromodomain and extra-terminal domain (pelabresib), the antiapoptotic proteins BCL-2/BCL-xL (navitoclax), MDM2 (navtemadlin), phosphatidylinositol 3-kinase (parsaclisib), or telomerase (imetelstat). EXPERT OPINION Patients with disease related cytopenias are ineligible for currently approved JAK2 inhibitors. However, momelotinib and pacritinib may be able to fill this void. Novel therapies are being evaluated in the upfront setting to improve the depth and duration of responses with ruxolitinib. Future evaluation of agents must be judged on their potential to modify disease progression, which current JAK2 inhibitors lack. Combination therapy, possibly with an immunotherapeutic agent might serve as key components of future myelofibrosis treatment options.
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Affiliation(s)
- Douglas Tremblay
- Division of Hematology and Medical Oncology, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA10029
| | - Ronald Hoffman
- Division of Hematology and Medical Oncology, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA10029
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Nguyen THD. Structural biology of human telomerase: progress and prospects. Biochem Soc Trans 2021; 49:1927-1939. [PMID: 34623385 PMCID: PMC8589416 DOI: 10.1042/bst20200042] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 09/08/2021] [Accepted: 09/10/2021] [Indexed: 12/28/2022]
Abstract
Telomerase ribonucleoprotein was discovered over three decades ago as a specialized reverse transcriptase that adds telomeric repeats to the ends of linear eukaryotic chromosomes. Telomerase plays key roles in maintaining genome stability; and its dysfunction and misregulation have been linked to different types of cancers and a spectrum of human genetic disorders. Over the years, a wealth of genetic and biochemical studies of human telomerase have illuminated its numerous fascinating features. Yet, structural studies of human telomerase have lagged behind due to various challenges. Recent technical developments in cryo-electron microscopy have allowed for the first detailed visualization of the human telomerase holoenzyme, revealing unprecedented insights into its active site and assembly. This review summarizes the cumulative work leading to the recent structural advances, as well as highlights how the future structural work will further advance our understanding of this enzyme.
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Affiliation(s)
- Thi Hoang Duong Nguyen
- Structural Studies Division, Medical Research Council Laboratory of Molecular Biology, Cambridge, U.K
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