1
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Rafat A, Dizaji Asl K, Mazloumi Z, Talebi M, Nozad Charoudeh H. Natural killer cells in combination with the inhibition of telomerase induced apoptosis in Acute Myeloid Leukemia cells. Biochem Biophys Rep 2025; 42:102027. [PMID: 40342534 PMCID: PMC12059324 DOI: 10.1016/j.bbrep.2025.102027] [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: 11/29/2024] [Revised: 04/16/2025] [Accepted: 04/22/2025] [Indexed: 05/11/2025] Open
Abstract
Background Recent trends in developing new treatments for cancers, highlight the use of immune cells particularly Natural Killer (NK) cells, as promising therapeutic strategies. While NK cells exhibit significant anti-tumor effects, their effectiveness is often limited. This study investigated the impact of BIBR1532, a human telomerase reverse transcriptase (hTERT) inhibitor, on improving the cytotoxicity of NK cells against Acute Myeloid Leukemia (AML) cells. Methods Primary AML cells and Kg-1a cell lines were cultured and treated with the half-maximal inhibitory concentration (IC50) of BIBR1532 for 48 h. The treated cells were then co-cultured with NK cells, after which cytotoxicity, cell proliferation, and apoptosis were assessed using Annexin V/7-AAD and Ki-67 expression analysis. Finally, apoptosis-related genes and proteins, hTERT gene and caspase 3/7 activity were studied. Results The Telomerase Inhibition (TI) in primary AML and Kg-1a cells with IC50 values of 38.75 μM and 57.64 μM, respectively, sensitized the AML cells and enhanced the anti-proliferative effects of NK cells. The combination of BIBR1532 and NK cells led to increased apoptosis, as indicated by the upregulation of the Bax and Bad genes, an increased Bax/Bcl-2 ratio, caspase 3/7 activity, Bax protein and a downregulation of mRNA expression levels of Bcl-2, Bcl-xl and decreased Bcl-2 protein. Conclusion The findings of this study demonstrate that the concurrent application of BIBR1532 and NK cells promotes apoptosis and reduces proliferation by targeting apoptosis-related genes and proteins such as Bax and Bcl-2.
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Affiliation(s)
- Ali Rafat
- Student Research Committee, Tabriz University of Medical Sciences, Tabriz, Iran
- Anatomical Sciences Research Center, Institute for Basic Sciences, Kashan University of Medical Sciences, Kashan, Iran
| | - Khadijeh Dizaji Asl
- Department of Histopathology and Anatomy, Faculty of Medical Sciences, Tabriz Medical Sciences, Islamic Azad University, Tabriz, Iran
| | - Zeinab Mazloumi
- Department of Applied Cell Sciences, Faculty of Advanced Medical Sciences, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Mehdi Talebi
- Department of Applied Cell Sciences, Faculty of Advanced Medical Sciences, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Hojjatollah Nozad Charoudeh
- Stem Cell Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
- Scientific Center of Zoology and Hydroecology, NAS RA, Yerevan, Armenia
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2
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Long W, Zeng YX, Zheng BX, Li YB, Wang YK, Chan KH, She MT, Lu YJ, Cao C, Wong WL. Targeting hTERT Promoter G-Quadruplex DNA Structures with Small-Molecule Ligand to Downregulate hTERT Expression for Triple-Negative Breast Cancer Therapy. J Med Chem 2024; 67:13363-13382. [PMID: 38987863 DOI: 10.1021/acs.jmedchem.4c01255] [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: 07/12/2024]
Abstract
Human telomerase reverse transcriptase (hTERT) may have noncanonical functions in transcriptional regulation and metabolic reprogramming in cancer cells, but it is a challenging target. We thus developed small-molecule ligands targeting hTERT promoter G-quadruplex DNA structures (hTERT G4) to downregulate hTERT expression. Ligand 5 showed high affinity toward hTERT G4 (Kd = 1.1 μM) and potent activity against triple-negative breast cancer cells (MDA-MB-231, IC50 = 1 μM). In cell-based assays, 5 not only exerts markedly inhibitory activity on classical telomere functions including decreased telomerase activity, shortened telomere length, and cellular senescence but also induces DNA damage, acute cellular senescence, and apoptosis. This study reveals that hTERT G4-targeting ligand may cause mitochondrial dysfunction, disrupt iron metabolism and activate ferroptosis in cancer cells. The in vivo antitumor efficacy of 5 was also evaluated in an MDA-MB-231 xenograft mouse model and approximately 78.7% tumor weight reduction was achieved. No observable toxicity against the major organs was observed.
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Affiliation(s)
- Wei Long
- State Key Laboratory of Chemical Biology and Drug Discovery, Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong SAR 999077, China
| | - Yao-Xun Zeng
- State Key Laboratory of Chemical Biology and Drug Discovery, Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong SAR 999077, China
| | - Bo-Xin Zheng
- State Key Laboratory of Chemical Biology and Drug Discovery, Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong SAR 999077, China
| | - Yu-Bo Li
- State Key Laboratory of Chemical Biology, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, China
| | - Ya-Kun Wang
- State Key Laboratory of Chemical Biology and Drug Discovery, Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong SAR 999077, China
| | - Ka-Hin Chan
- State Key Laboratory of Chemical Biology and Drug Discovery, Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong SAR 999077, China
| | - Meng-Ting She
- State Key Laboratory of Chemical Biology and Drug Discovery, Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong SAR 999077, China
| | - Yu-Jing Lu
- School of Biomedical and Pharmaceutical Sciences, Guangdong University of Technology Guangzhou 510006, China
| | - Chunyang Cao
- State Key Laboratory of Chemical Biology, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, China
| | - Wing-Leung Wong
- State Key Laboratory of Chemical Biology and Drug Discovery, Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong SAR 999077, China
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3
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Jayaprasad AG, Chandrasekharan A, Arun Jyothi SP, John Sam SM, Santhoshkumar TR, Pillai MR. Telomerase inhibitors induce mitochondrial oxidation and DNA damage-dependent cell death rescued by Bcl-2/Bcl-xL. Int J Biol Macromol 2024; 264:130151. [PMID: 38403227 DOI: 10.1016/j.ijbiomac.2024.130151] [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: 12/18/2023] [Revised: 02/05/2024] [Accepted: 02/11/2024] [Indexed: 02/27/2024]
Abstract
BACKGROUND Reactivation of telomerase is a hallmark of cancer and the majority of cancers over-express telomerase. Telomerase-dependent telomere length maintenance confers immortality to cancer cells. However, telomere length-independent cell survival functions of telomerase also play a critical role in tumorigenesis. Multiple telomerase inhibitors have been developed as therapeutics and include anti-sense oligonucleotides, telomerase RNA component targeting agents, chemical inhibitors of telomerase, small molecule inhibitors of hTERT, and telomerase vaccine. In general, telomerase inhibitors affect cell proliferation and survival of cells depending on the telomere length reduction, culminating in replicative senescence or cell death by crisis. However, most telomerase inhibitors kill cancer cells prior to significant reduction in telomere length, suggesting telomere length independent role of telomerase in early telomere dysfunction-dependent cell death. METHODS In this study, we explored the mechanism of cell death induced by three prominent telomerase inhibitors utilizing a series of genetically encoded sensor cells including redox and DNA damage sensor cells. RESULTS We report that telomerase inhibitors induce early cell cycle inhibition, followed by redox alterations at cytosol and mitochondria. Massive mitochondrial oxidation and DNA damage induce classical cell death involving mitochondrial transmembrane potential loss and mitochondrial permeabilization. Real-time imaging of the progression of mitochondrial oxidation revealed that treated cells undergo a biphasic mitochondrial redox alteration during telomerase inhibition, emphasizing the potential role of telomerase in the redox regulation at mitochondria. Additionally, silencing of hTERT confirmed its predominant role in maintaining mitochondrial redox homeostasis. Interestingly, the study also demonstrated that anti-apoptotic Bcl-2 family proteins still confer protection against cell death induced by telomerase inhibitors. CONCLUSION The study demonstrates that redox alterations and DNA damage contribute to early cell death by telomerase inhibitors and anti-apoptotic Bcl-2 family proteins confer protection from cell death by their ability to safeguard mitochondria from oxidation damage.
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Affiliation(s)
- Aparna Geetha Jayaprasad
- Cancer Research Program, Rajiv Gandhi Centre for Biotechnology, Poojappura, Thycaud, Thiruvananthapuram 695014, Kerala, India; PhD Program, Manipal Academy of Higher Education (MAHE), Madhav Nagar, Manipal, Karnataka 576104, India
| | - Aneesh Chandrasekharan
- Cancer Research Program, Rajiv Gandhi Centre for Biotechnology, Poojappura, Thycaud, Thiruvananthapuram 695014, Kerala, India
| | - S P Arun Jyothi
- Cancer Research Program, Rajiv Gandhi Centre for Biotechnology, Poojappura, Thycaud, Thiruvananthapuram 695014, Kerala, India
| | - S M John Sam
- Cancer Research Program, Rajiv Gandhi Centre for Biotechnology, Poojappura, Thycaud, Thiruvananthapuram 695014, Kerala, India
| | - T R Santhoshkumar
- Cancer Research Program, Rajiv Gandhi Centre for Biotechnology, Poojappura, Thycaud, Thiruvananthapuram 695014, Kerala, India.
| | - M Radhakrishna Pillai
- Cancer Research Program, Rajiv Gandhi Centre for Biotechnology, Poojappura, Thycaud, Thiruvananthapuram 695014, Kerala, India.
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4
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Gala K, Jain M, Shah P, Pandey A, Garg M, Khattar E. Role of p53 transcription factor in determining the efficacy of telomerase inhibitors in cancer treatment. Life Sci 2024; 339:122416. [PMID: 38216120 DOI: 10.1016/j.lfs.2024.122416] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2023] [Revised: 12/29/2023] [Accepted: 01/05/2024] [Indexed: 01/14/2024]
Abstract
AIM Telomerase expression is unique to cancer cells, making it a promising target for therapy. However, a major drawback of telomerase inhibition is that it affects cancer cell proliferation only when telomeres shorten, creating a lag phase post-continuous drug treatment. Acute cytotoxicity of telomerase inhibitors is dependent on their ability to induce DNA damage. p53 senses DNA damage and is the primary effector required for sensitizing cells towards apoptosis. MAIN METHODS Isogenic p53+/+ and p53-/- ovarian cancer cell lines were generated using the CRISPR/Cas9 system and the anti-cancer effect of telomerase inhibitors MST-312 and BIBR1532 were determined. Flow cytometry, real-time PCR, and western blot were performed to study cell cycle, apoptosis, and gene expression. KEY FINDINGS We report that MST-312 exhibits p53-dependent cytotoxicity, while BIBR1532 exhibits p53-independent cytotoxicity. Colony-forming ability also confirms the p53-dependent effect of MST-312. Re-expression of p53 in p53-/- cells could rescue MST-312 sensitivity. In p53+/+ cells, MST-312 causes S phase arrest and activation of p53-dependent target genes like anti-apoptosis markers (Fas and Puma) and cell cycle markers (p21 and cyclinB). In p53-/- cells, MST-312 causes S/G2/M arrest. BIBR1532 induces S/G2/M phase cell cycle arrest irrespective of p53 status. This correlates with the expression of the DNA damage marker (γ-H2AX). Long-term continuous treatment with MST-312 or BIBR1532 results in p53-independent telomere shortening. SIGNIFICANCE In summary, we demonstrate that acute anti-cancer effects of MST-312 are dependent on p53 expression. Hence, it is important to consider the p53 expression status in cancer cells when selecting and administering telomerase inhibitors.
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Affiliation(s)
- Kavita Gala
- Sunandan Divatia School of Science, SVKM's NMIMS (Deemed to be) University, Vile Parle West, Mumbai 400056, India
| | - Meghna Jain
- Sunandan Divatia School of Science, SVKM's NMIMS (Deemed to be) University, Vile Parle West, Mumbai 400056, India
| | - Prachi Shah
- Sunandan Divatia School of Science, SVKM's NMIMS (Deemed to be) University, Vile Parle West, Mumbai 400056, India
| | - Amit Pandey
- Department of Biotechnology, National Institute of Pharmaceutical Education and Research (NIPER), Ahmedabad, Gandhinagar 382355, Gujarat, India
| | - Manoj Garg
- Amity Institute of Molecular Medicine & Stem Cell Research (AIMMSCR), Amity University, Sector-125, Noida 201313, India
| | - Ekta Khattar
- Sunandan Divatia School of Science, SVKM's NMIMS (Deemed to be) University, Vile Parle West, Mumbai 400056, India.
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5
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Di Nunno V, Aprile M, Bartolini S, Gatto L, Tosoni A, Ranieri L, De Biase D, Asioli S, Franceschi E. The Biological and Clinical Role of the Telomerase Reverse Transcriptase Gene in Glioblastoma: A Potential Therapeutic Target? Cells 2023; 13:44. [PMID: 38201248 PMCID: PMC10778438 DOI: 10.3390/cells13010044] [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: 10/25/2023] [Revised: 12/15/2023] [Accepted: 12/18/2023] [Indexed: 01/12/2024] Open
Abstract
Glioblastoma IDH-wildtype represents the most lethal and frequent primary tumor of the central nervous system. Thanks to important scientific efforts, we can now investigate its deep genomic assessment, elucidating mutated genes and altered biological mechanisms in addition to its clinical aggressiveness. The telomerase reverse transcriptase gene (TERT) is the most frequently altered gene in solid tumors, including brain tumors and GBM IDH-wildtype. In particular, it can be observed in approximately 80-90% of GBM IDH-wildtype cases. Its clonal distribution on almost all cancer cells makes this gene an optimal target. However, the research of effective TERT inhibitors is complicated by several biological and clinical obstacles which can be only partially surmounted. Very recently, novel immunological approaches leading to TERT inhibition have been investigated, offering the potential to develop an effective target for this altered protein. Here, we perform a narrative review investigating the biological role of TERT alterations on glioblastoma and the principal obstacles associated with TERT inhibitions in this population. Moreover, we discuss possible combination treatment strategies to overcome these limitations.
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Affiliation(s)
- Vincenzo Di Nunno
- Nervous System Medical Oncology Department, IRCCS Istituto delle Scienze Neurologiche di Bologna, 40139 Bologna, Italy (E.F.)
| | - Marta Aprile
- Department of Experimental, Diagnostic and Specialty Medicine, University of Bologna, 40138 Bologna, Italy
| | - Stefania Bartolini
- Nervous System Medical Oncology Department, IRCCS Istituto delle Scienze Neurologiche di Bologna, 40139 Bologna, Italy (E.F.)
| | - Lidia Gatto
- Department of Oncology, Azienda Unità Sanitaria Locale (AUSL) Bologna, 40139 Bologna, Italy
| | - Alicia Tosoni
- Nervous System Medical Oncology Department, IRCCS Istituto delle Scienze Neurologiche di Bologna, 40139 Bologna, Italy (E.F.)
| | - Lucia Ranieri
- Nervous System Medical Oncology Department, IRCCS Istituto delle Scienze Neurologiche di Bologna, 40139 Bologna, Italy (E.F.)
| | - Dario De Biase
- Solid Tumor Molecular Pathology Laboratory, IRCCS Azienda Ospedaliero-Universitaria di Bologna, 40138 Bologna, Italy
- Department of Pharmacy and Biotechnology (FaBit), University of Bologna, 40126 Bologna, Italy
| | - Sofia Asioli
- IRCCS Istituto delle Scienze Neurologiche di Bologna, 40139 Bologna, Italy
- Department of Biomedical and Neuromotor Sciences (DIBINEM), Surgical Pathology Section, Alma Mater Studiorum, University of Bologna, 40126 Bologna, Italy
| | - Enrico Franceschi
- Nervous System Medical Oncology Department, IRCCS Istituto delle Scienze Neurologiche di Bologna, 40139 Bologna, Italy (E.F.)
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6
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Ebata H, Shima T, Iizuka R, Uemura S. Accumulation of TERT in mitochondria exerts two opposing effects on apoptosis. FEBS Open Bio 2023; 13:1667-1682. [PMID: 37525387 PMCID: PMC10476567 DOI: 10.1002/2211-5463.13682] [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: 06/15/2022] [Revised: 07/18/2023] [Accepted: 07/31/2023] [Indexed: 08/02/2023] Open
Abstract
Telomerase reverse transcriptase (TERT) is a protein that catalyzes the reverse transcription of telomere elongation. TERT is also expected to play a non-canonical role beyond telomere lengthening since it localizes not only in the nucleus but also in mitochondria, where telomeres do not exist. Several studies have reported that mitochondrial TERT regulates apoptosis induced by oxidative stress. However, there is still some controversy as to whether mitochondrial TERT promotes or inhibits apoptosis, mainly due to the lack of information on changes in TERT distribution in individual cells over time. Here, we simultaneously detected apoptosis and TERT localization after oxidative stress in individual HeLa cells by live-cell tracking. Single-cell tracking revealed that the stress-induced accumulation of TERT in mitochondria caused apoptosis, but that accumulation increased over time until cell death. The results suggest a new model in which mitochondrial TERT has two opposing effects at different stages of apoptosis: it predetermines apoptosis at the first stage of cell-fate determination, but also delays apoptosis at the second stage. As such, our data support a model that integrates the two opposing hypotheses on mitochondrial TERT's effect on apoptosis. Furthermore, detailed statistical analysis of TERT mutations, which have been predicted to inhibit TERT transport to mitochondria, revealed that these mutations suppress apoptosis independent of mitochondrial localization of TERT. Together, these results imply that the non-canonical functions of TERT affect a wide range of mitochondria-dependent and mitochondria-independent apoptosis pathways.
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Affiliation(s)
- Hiroshi Ebata
- Department of Biological Sciences, Graduate School of ScienceThe University of TokyoJapan
- Present address:
Buck Institute for Research on AgingNovatoCAUSA
| | - Tomohiro Shima
- Department of Biological Sciences, Graduate School of ScienceThe University of TokyoJapan
| | - Ryo Iizuka
- Department of Biological Sciences, Graduate School of ScienceThe University of TokyoJapan
| | - Sotaro Uemura
- Department of Biological Sciences, Graduate School of ScienceThe University of TokyoJapan
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7
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Waksal JA, Bruedigam C, Komrokji RS, Jamieson CHM, Mascarenhas JO. Telomerase-targeted therapies in myeloid malignancies. Blood Adv 2023; 7:4302-4314. [PMID: 37216228 PMCID: PMC10424149 DOI: 10.1182/bloodadvances.2023009903] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 05/08/2023] [Accepted: 05/14/2023] [Indexed: 05/24/2023] Open
Abstract
Human telomeres are tandem arrays that are predominantly composed of 5'-TTAGGG-3' nucleotide sequences at the terminal ends of chromosomes. These sequences serve 2 primary functions: they preserve genomic integrity by protecting the ends of chromosomes, preventing inappropriate degradation by DNA repair mechanisms, and they prevent loss of genetic information during cellular division. When telomeres shorten to reach a critical length, termed the Hayflick limit, cell senescence or death is triggered. Telomerase is a key enzyme involved in synthesizing and maintaining the length of telomeres within rapidly dividing cells and is upregulated across nearly all malignant cells. Accordingly, targeting telomerase to inhibit uncontrolled cell growth has been an area of great interest for decades. In this review, we summarize telomere and telomerase biology because it relates to both physiologic and malignant cells. We discuss the development of telomere- and telomerase-targeted therapeutic candidates within the realm of myeloid malignancies. We overview all mechanisms of targeting telomerase that are currently in development, with a particular focus on imetelstat, an oligonucleotide with direct telomerase inhibitory properties that has advanced the furthest in clinical development and has demonstrated promising data in multiple myeloid malignancies.
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Affiliation(s)
- Julian A. Waksal
- Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Claudia Bruedigam
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
- School of Biomedical Sciences, The University of Queensland, Brisbane, Australia
| | | | | | - John O. Mascarenhas
- Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY
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8
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Amin A, Morello M, Petrara MR, Rizzo B, Argenton F, De Rossi A, Giunco S. Short-Term TERT Inhibition Impairs Cellular Proliferation via a Telomere Length-Independent Mechanism and Can Be Exploited as a Potential Anticancer Approach. Cancers (Basel) 2023; 15:2673. [PMID: 37345011 DOI: 10.3390/cancers15102673] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 04/21/2023] [Accepted: 05/04/2023] [Indexed: 06/23/2023] Open
Abstract
Telomerase reverse transcriptase (TERT), the catalytic component of telomerase, may also contribute to carcinogenesis via telomere-length independent mechanisms. Our previous in vitro and in vivo studies demonstrated that short-term telomerase inhibition by BIBR1532 impairs cell proliferation without affecting telomere length. Here, we show that the impaired cell cycle progression following short-term TERT inhibition by BIBR1532 in in vitro models of B-cell lymphoproliferative disorders, i.e., Epstein-Barr virus (EBV)-immortalized lymphoblastoid cell lines (LCLs), and B-cell malignancies, i.e., Burkitt's lymphoma (BL) cell lines, is characterized by a significant reduction in NF-κB p65 nuclear levels leading to the downregulation of its target gene MYC. MYC downregulation was associated with increased expression and nuclear localization of P21, thus promoting its cell cycle inhibitory function. Consistently, treatment with BIBR1532 in wild-type zebrafish embryos significantly decreased Myc and increased p21 expression. The combination of BIBR1532 with antineoplastic drugs (cyclophosphamide or fludarabine) significantly reduced xenografted cells' proliferation rate compared to monotherapy in the zebrafish xenograft model. Overall, these findings indicate that short-term inhibition of TERT impairs cell growth through the downregulation of MYC via NF-κB signalling and supports the use of TERT inhibitors in combination with antineoplastic drugs as an efficient anticancer strategy.
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Affiliation(s)
- Aamir Amin
- Department of Surgery, Oncology and Gastroenterology, Section of Oncology and Immunology, University of Padova, 35128 Padova, Italy
| | - Marzia Morello
- Immunology and Diagnostic Molecular Oncology Unit, Veneto Institute of Oncology IOV-IRCCS, 35128 Padova, Italy
| | - Maria Raffaella Petrara
- Department of Surgery, Oncology and Gastroenterology, Section of Oncology and Immunology, University of Padova, 35128 Padova, Italy
| | - Beatrice Rizzo
- Immunology and Diagnostic Molecular Oncology Unit, Veneto Institute of Oncology IOV-IRCCS, 35128 Padova, Italy
| | | | - Anita De Rossi
- Department of Surgery, Oncology and Gastroenterology, Section of Oncology and Immunology, University of Padova, 35128 Padova, Italy
- Immunology and Diagnostic Molecular Oncology Unit, Veneto Institute of Oncology IOV-IRCCS, 35128 Padova, Italy
| | - Silvia Giunco
- Department of Surgery, Oncology and Gastroenterology, Section of Oncology and Immunology, University of Padova, 35128 Padova, Italy
- Immunology and Diagnostic Molecular Oncology Unit, Veneto Institute of Oncology IOV-IRCCS, 35128 Padova, Italy
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9
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Palamarchuk AI, Kovalenko EI, Streltsova MA. Multiple Actions of Telomerase Reverse Transcriptase in Cell Death Regulation. Biomedicines 2023; 11:biomedicines11041091. [PMID: 37189709 DOI: 10.3390/biomedicines11041091] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 03/25/2023] [Accepted: 04/02/2023] [Indexed: 04/07/2023] Open
Abstract
Telomerase reverse transcriptase (TERT), a core part of telomerase, has been known for a long time only for its telomere lengthening function by reverse transcription of RNA template. Currently, TERT is considered as an intriguing link between multiple signaling pathways. The diverse intracellular localization of TERT corresponds to a wide range of functional activities. In addition to the canonical function of protecting chromosome ends, TERT by itself or as a part of the telomerase complex participates in cell stress responses, gene regulation and mitochondria functioning. Upregulation of TERT expression and increased telomerase activity in cancer and somatic cells relate to improved survival and persistence of such cells. In this review, we summarize the data for a comprehensive understanding of the role of TERT in cell death regulation, with a focus on the interaction of TERT with signaling pathways involved in cell survival and stress response.
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Affiliation(s)
- Anastasia I. Palamarchuk
- Shemyakin & Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Ul. Miklukho-Maklaya 16/10, 117997 Moscow, Russia
| | - Elena I. Kovalenko
- Shemyakin & Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Ul. Miklukho-Maklaya 16/10, 117997 Moscow, Russia
| | - Maria A. Streltsova
- Shemyakin & Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Ul. Miklukho-Maklaya 16/10, 117997 Moscow, Russia
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10
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Uno Y, Tanaka H, Miyakawa K, Akiyama N, Kamikokura Y, Yuzawa S, Kitada M, Takei H, Tanino M. Subcellular localization of hTERT in breast cancer: insights into its tumorigenesis and drug resistance mechanisms in HER2-immunopositive breast cancer. Hum Pathol 2022; 134:74-84. [PMID: 36549600 DOI: 10.1016/j.humpath.2022.12.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 12/14/2022] [Accepted: 12/15/2022] [Indexed: 12/24/2022]
Abstract
Human telomerase reverse transcriptase (hTERT) is highly expressed in various cancers, including breast cancer. Although telomere elongation is an essential role for hTERT, the nuclear export after oxdative stress has also been shown in several cancer cell lines and is associated with drug-resistance in vitro. As only a few reports focused on the subcellular localization of hTERT in clinical specimens, we performed immunohistochemistry (IHC) and analyzed the correlation between intracellular hTERT expression and the clinicopathological characteristics to identify the clinical significance of hTERT subcellular expression in breast cancers. 144 invasive breast cancers classified by IHC subtype without primary systemic therapy (PST), were selected from a surgical resection cohort and were immunostained for hTERT, p-STAT3, p-AKT and p-ERK. The nuclear and/or cytoplasmic staining intensity and proportion of hTERT were scored and compared with clinicopathological parameters. The nuclear hTERT expression was significantly correlated with HER2 expression (p = 0.00156), and the scores were significantly correlated with p-STAT3 and p-AKT expression scores (r = 0.532, p = 0.000587 and r = 0.345, p = 0.0339, respectively) in the HER2-immunopositive breast cancer including luminal-HER2 and HER2 subtypes. Furthermore, hTERT was expressed more in cytoplasm in the specimens after PST than those before PST, and the score tended to be negatively correlated with tumor shrinkage rate in HER2 subtype (r = -0.593, p = 0.0705). These results suggest that nuclear and/or cytoplasmic hTERT may play a different role before and after PST including the tumorigenesis and drug-resistance in breast cancer. Suppression of cytoplasmic hTERT expression may lead to more effective strategy for drug-resistant HER2 subtype in breast cancer.
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Affiliation(s)
- Yuji Uno
- Department of Diagnostic Pathology, Asahikawa Medical University Hospital, Midorigaoka-Higashi 2-1-1-1, Asahikawa, Hokkaido, 0788510, Japan
| | - Hiroki Tanaka
- Division of Tumor Pathology, Department of Pathology, Asahikawa Medical University, Midorigaoka-Higashi 2-1-1-1, Asahikawa, Hokkaido, 0788510, Japan
| | - Keita Miyakawa
- Department of Diagnostic Pathology, Asahikawa Medical University Hospital, Midorigaoka-Higashi 2-1-1-1, Asahikawa, Hokkaido, 0788510, Japan
| | - Naoko Akiyama
- Department of Diagnostic Pathology, Asahikawa Medical University Hospital, Midorigaoka-Higashi 2-1-1-1, Asahikawa, Hokkaido, 0788510, Japan
| | - Yuki Kamikokura
- Department of Diagnostic Pathology, Asahikawa Medical University Hospital, Midorigaoka-Higashi 2-1-1-1, Asahikawa, Hokkaido, 0788510, Japan
| | - Sayaka Yuzawa
- Department of Diagnostic Pathology, Asahikawa Medical University Hospital, Midorigaoka-Higashi 2-1-1-1, Asahikawa, Hokkaido, 0788510, Japan
| | - Masahiro Kitada
- Breast Center, Asahikawa Medical University Hospital, Midorigaoka-Higashi 2-1-1-1, Asahikawa, Hokkaido, 0788510, Japan
| | - Hidehiro Takei
- Ochsner LSU Health Shreveport-Academic Medical Center, 1541 Kings Highway Shreveport, LA, 71103, USA
| | - Mishie Tanino
- Department of Diagnostic Pathology, Asahikawa Medical University Hospital, Midorigaoka-Higashi 2-1-1-1, Asahikawa, Hokkaido, 0788510, Japan.
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11
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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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12
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Miller J, Dakic A, Spurgeon M, Saenz F, Kallakury B, Zhao B, Zhang J, Zhu J, Ma Q, Xu Y, Lambert P, Schlegel R, Riegel AT, Liu X. AIB1 is a novel target of the high-risk HPV E6 protein and a biomarker of cervical cancer progression. J Med Virol 2022; 94:3962-3977. [PMID: 35437795 PMCID: PMC9199254 DOI: 10.1002/jmv.27795] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 04/13/2022] [Accepted: 04/17/2022] [Indexed: 11/10/2022]
Abstract
The high-risk human papillomaviruses (HPV-16, -18) are critical etiologic agents in human malignancy, most importantly in cervical cancer. These oncogenic viruses encode the E6 and E7 proteins that are uniformly retained and expressed in cervical cancers and required for maintenance of the tumorigenic phenotype. The E6 and E7 proteins were first identified as targeting the p53 and pRB tumor suppressor pathways, respectively, in host cells, thereby leading to disruption of cell cycle controls. In addition to p53 degradation, a number of other functions and critical targets for E6 have been described, including telomerase, Myc, PDZ-containing proteins, Akt, Wnt, mTORC1, as well as others. In this study, we identified Amplified in Breast Cancer 1 (AIB1) as a new E6 target. We first found that E6 and hTERT altered similar profiling of gene expression in human foreskin keratinocytes (HFK), independent of telomerase activity. Importantly, AIB1 was a common transcriptional target of both E6 and hTERT. We then verified that high-risk E6 but not low-risk E6 expression led to increases in AIB1 transcript levels by real-time RT-PCR, suggesting that AIB1 upregulation may play an important role in cancer development. Western blots demonstrated that AIB1 expression increased in HPV-16 E6 and E7 expressing (E6E7) immortalized foreskin and cervical keratinocytes, and in three of four common cervical cancer cell lines as well. Then, we evaluated the expression of AIB1 in human cervical lesions and invasive carcinoma using immunohistochemical staining. Strikingly, AIB1 showed positivity in the nucleus of cells in the immediate suprabasal epithelium, while nuclei of the basal epithelium were negative, as evident in the Cervical Intraepithelial Neoplasia 1 (CIN1) samples. As the pathological grading of cervical lesions increased from CIN1, CIN2, CIN3 carcinoma in situ and invasive carcinoma, AIB1 staining increased progressively, suggesting that AIB1 may serve as a novel histological biomarker for cervical cancer development. For cases of invasive cervical carcinoma, AIB1 staining was specific to cancerous lesions. Increased expression of AIB1 was also observed in transgenic mouse cervical neoplasia and cancer models induced by E6E7 and estrogen. Knockdown of AIB1 expression in E6E7 immortalized human cervical cells significantly abolished cell proliferation. Taken together, these data support AIB1 as a novel target of HPV E6 and a biomarker of cervical cancer progression.
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Affiliation(s)
- Jonathan Miller
- Department of Pathology, Center for Cell ReprogrammingGeorgetown University Medical SchoolWashingtonDistrict of ColumbiaUSA
| | - Aleksandra Dakic
- Department of Pathology, Center for Cell ReprogrammingGeorgetown University Medical SchoolWashingtonDistrict of ColumbiaUSA
| | - Megan Spurgeon
- McArdle Laboratory for Cancer Research, Department of OncologyUniversity of Wisconsin‐Madison School of Medicine and Public HealthMadisonWisconsinUSA
| | - Francisco Saenz
- Department of Oncology, Lombardi Comprehensive Cancer CenterGeorgetown University Medical SchoolWashingtonDistrict of ColumbiaUSA
| | - Bhaskar Kallakury
- Department of Pathology, Center for Cell ReprogrammingGeorgetown University Medical SchoolWashingtonDistrict of ColumbiaUSA
| | - Bo Zhao
- Department of Medicine, Brigham and Women's HospitalHarvard Medical SchoolBostonMassachusettsUSA
| | - Junran Zhang
- Department of Radiation Oncology, Wexner Medical CenterThe Ohio State UniversityColumbusOhioUSA
- The James Comprehensive Cancer CenterThe Ohio State UniversityColumbusOhioUSA
| | - Jian Zhu
- Department of Pathology, Wexner Medical CenterThe Ohio State UniversityColumbusOhioUSA
| | - Qin Ma
- The James Comprehensive Cancer CenterThe Ohio State UniversityColumbusOhioUSA
- Department of Biomedical Informatics, College of MedicineThe Ohio State UniversityColumbusOhioUSA
| | - Ying Xu
- Computational Systems Biology Lab, Department of Biochemistry and Molecular Biology and Institute of BioinformaticsThe University of GeorgiaAthensGeorgiaUSA
| | - Paul Lambert
- McArdle Laboratory for Cancer Research, Department of OncologyUniversity of Wisconsin‐Madison School of Medicine and Public HealthMadisonWisconsinUSA
| | - Richard Schlegel
- Department of Pathology, Center for Cell ReprogrammingGeorgetown University Medical SchoolWashingtonDistrict of ColumbiaUSA
| | - Anna T. Riegel
- Department of Oncology, Lombardi Comprehensive Cancer CenterGeorgetown University Medical SchoolWashingtonDistrict of ColumbiaUSA
| | - Xuefeng Liu
- Department of Pathology, Center for Cell ReprogrammingGeorgetown University Medical SchoolWashingtonDistrict of ColumbiaUSA
- The James Comprehensive Cancer CenterThe Ohio State UniversityColumbusOhioUSA
- Department of Pathology, Wexner Medical CenterThe Ohio State UniversityColumbusOhioUSA
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13
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Umapathy D, Karthikeyan MC, Ponnuchamy K, Kannan MK, Ganeshan M, Arockiam AJV. The absence of cellular glucose triggers oncogene AEG-1 that instigates VEGFC in HCC: A possible genetic root cause of angiogenesis. Gene X 2022; 826:146446. [PMID: 35337853 DOI: 10.1016/j.gene.2022.146446] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Revised: 03/02/2022] [Accepted: 03/18/2022] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND AND OBJECTIVE Astrocyte Elevated Gene-1 (AEG-1) is the master and multi-regulator of the various transcriptional factor primarily regulating chemoresistance, angiogenesis, metastasis, and invasion under the pathological condition, including liver cancer. This study was focused on investigating the process of tumor angiogenesis in liver carcinoma by studying the role of AEG-1 under GD/2DG conditions. METHOD AND RESULTS The PCR and western blot analysis revealed that glucose depletion (GD) induces the overexpression of AEG-1. Further, it leads to the constant expression of VEGFC through the activation of HIF-1α/CCR7 via the stimulations of PI3K/Akt signaling pathways. GLUT2 is the major transporter of a glucose molecule that is highly participating under GD through the expression of AEG-1 and constantly expresses glucokinase (GCK). The obtained data suggest that AEG-1 act as an angiogenesis and glycolysis regulator by modulating the expression of GCK through HIF-1α and GLUT2. 2-deoxy-D-glucose (2DG) is a glycolysis inhibitor that induces impaired glycolysis and cellular apoptosis by cellular oxidative stress. The administration of 2DG has led to the chemoresistance of AEG-1. CONCLUSION The total findings of the study judged that disruption of cellular energy metabolism induced by the absence of glucose or the presence of mutant glucose moiety (2DG) promotes the overexpression of AEG-1. The GD/2DG activates the VEGFC by inducing the HIF-1α and CCR7. Moreover, AEG-1 induces the expression of OPN, which regulates metastasis, angiogenesis, and actively participates in protective autophagy by promoting LC3 a/b.
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Affiliation(s)
- Devan Umapathy
- Department of Biochemistry, Molecular Oncology Laboratory, School of Life Sciences, Bharathidasan University, Tiruchirappalli 620 024, Tamil Nadu, India
| | - Mano Chitra Karthikeyan
- Department of Biochemistry, Molecular Oncology Laboratory, School of Life Sciences, Bharathidasan University, Tiruchirappalli 620 024, Tamil Nadu, India
| | - Kumar Ponnuchamy
- Department of Animal Health and Management, Food Chemistry and Molecular Cancer Biology Laboratory, Alagappa University, Karaikudi 630 003, Tamil Nadu, India
| | - Mahesh Kumar Kannan
- Department of Biochemistry, Molecular Oncology Laboratory, School of Life Sciences, Bharathidasan University, Tiruchirappalli 620 024, Tamil Nadu, India
| | - Mathan Ganeshan
- Cancer Biology Laboratory, Department of Biomedical Science, School of Life Sciences, Bharathidasan University, Tiruchirappalli 620 024, Tamil Nadu, India
| | - Antony Joseph Velanganni Arockiam
- Department of Biochemistry, Molecular Oncology Laboratory, School of Life Sciences, Bharathidasan University, Tiruchirappalli 620 024, Tamil Nadu, India.
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14
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Li CL, Yeh SH, Chen PJ. Circulating Virus–Host Chimera DNAs in the Clinical Monitoring of Virus-Related Cancers. Cancers (Basel) 2022; 14:cancers14102531. [PMID: 35626135 PMCID: PMC9139492 DOI: 10.3390/cancers14102531] [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: 03/18/2022] [Revised: 05/18/2022] [Accepted: 05/18/2022] [Indexed: 11/16/2022] Open
Abstract
Simple Summary Cell-free tumor DNA (ctDNA), the DNA released into circulation from tumors, is a promising tumor marker with versatile applications. The associations of the amount, somatic mutation frequency, and epigenetic modifications of ctDNA with the tumor burden, tumor behavior, and prognosis have been widely investigated in different types of tumors. However, there are still some challenging issues to be resolved before ctDNA can complement or even replace current serum tumor markers. We propose employing exogenous viral DNA integration that produces unique virus–host chimera DNA (vh-DNA) at junction sites. Cell-free vh-DNA may become a new biomarker because it overcomes background interference detection problems, takes advantage of virus tropism to localize the tumor, and acts as a universal marker for monitoring clonal expansion or tumor loads in tumors related to oncogenic viruses. Abstract The idea of using tumor-specific cell-free DNA (ctDNA) as a tumor biomarker has been widely tested and validated in various types of human cancers and different clinical settings. ctDNA can reflect the presence or size of tumors in a real-time manner and can enable longitudinal monitoring with minimal invasiveness, allowing it to be applied in treatment response assessment and recurrence monitoring for cancer therapies. However, tumor detection by ctDNA remains a great challenge due to the difficulty in enriching ctDNA from a large amount of homologous non-tumor cell-free DNA (cfDNA). Only ctDNA with nonhuman sequences (or rearrangements) can be selected from the background of cfDNA from nontumor DNAs. This is possible for several virus-related cancers, such as hepatitis B virus (HBV)-related HCC or human papillomavirus (HPV)-related cervical or head and neck cancers, which frequently harbor randomly integrated viral DNA. The junction fragments of the integrations, namely virus–host chimera DNA (vh-DNA), can represent the signatures of individual tumors and are released into the blood. Such ctDNA can be enriched by capture with virus-specific probes and therefore exploited as a circulating biomarker to track virus-related cancers in clinical settings. Here, we review virus integrations in virus-related cancers to evaluate the feasibility of vh-DNA as a cell-free tumor marker and update studies on the development of detection and applications. vh-DNA may be a solution to the development of specific markers to manage virus-related cancers in the future.
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Affiliation(s)
- Chiao-Ling Li
- Graduate Institute of Microbiology, College of Medicine, National Taiwan University, Taipei 100, Taiwan;
| | - Shiou-Hwei Yeh
- Graduate Institute of Microbiology, College of Medicine, National Taiwan University, Taipei 100, Taiwan;
- Center for Genomic Medicine, College of Medicine, National Taiwan University, Taipei 100, Taiwan
- Department of Clinical Laboratory Sciences and Medical Biotechnology, College of Medicine, National Taiwan University, Taipei 100, Taiwan
- Correspondence: (S.-H.Y.); (P.-J.C.)
| | - Pei-Jer Chen
- Center for Genomic Medicine, College of Medicine, National Taiwan University, Taipei 100, Taiwan
- Graduate Institute of Clinical Medicine, College of Medicine, National Taiwan University, Taipei 100, Taiwan
- Division of Gastroenterology, Department of Internal Medicine, National Taiwan University Hospital, Taipei 100, Taiwan
- Correspondence: (S.-H.Y.); (P.-J.C.)
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15
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Rafat A, Dizaji Asl K, Mazloumi Z, Movassaghpour AA, Talebi M, Shanehbandi D, Farahzadi R, Nejati B, Nozad Charoudeh H. Telomerase inhibition on acute myeloid leukemia stem cell induced apoptosis with both intrinsic and extrinsic pathways. Life Sci 2022; 295:120402. [PMID: 35176279 DOI: 10.1016/j.lfs.2022.120402] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 02/07/2022] [Accepted: 02/09/2022] [Indexed: 12/24/2022]
Abstract
AIMS Acute Myeloid Leukemia (AML) is an invasive and lethal blood cancer caused by a rare population of Leukemia Stem Cells (LSCs). Telomerase activation is a limitless self-renewal process in LSCs. Apart from telomerase role in telomere lengthening, telomerase (especially hTERT subunit) inhibits intrinsic-, extrinsic-, and p53- mediated apoptosis pathways. In this study, the effect of Telomerase Inhibition (TI) on intrinsic-, extrinsic-, p53-mediated apoptosis, and DNMT3a and TET epigenetic markers in stem (CD34+) and differentiated (CD34-) AML cells is evaluated. MAIN METHODS High-purity CD34+ (primary AML and KG-1a) cells were enriched using the Magnetic-Activated Cell Sorting (MACS) system. CD34+ and CD34- (primary AML and KG-1a) cells were treated with BIBR1532 and then, MTT assay, Annexin V/7AAD, Ki-67 assay, Telomere Length (TL) measurement, and transcriptional alterations of p53, hTERT, TET2, DNMT3a were analyzed. Finally, apoptosis-related genes and proteins were studied. KEY FINDINGS TI with the IC50 values of 83.5, 33.2, 54.3, and 24.6 μM in CD34+ and CD34- (primary AML and KG-1a) cells significantly inhibited cell proliferation and induced apoptosis. However, TI had no significant effect on TL. The results also suggested TI induced intrinsic-, extrinsic-, and p53-mediated apoptosis. It was shown that the expression levels of DNMT3a and TET2 epigenetic markers were highly increased following TI. SIGNIFICANCE In total, it was revealed that TI induced apoptosis through intrinsic, extrinsic, and p53 pathways and increased the expression of DNMT3a and TET2 epigenetic markers.
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Affiliation(s)
- Ali Rafat
- Stem Cell Research Center, Tabriz University of Medical Sciences, Tabriz, Iran; Department of Anatomical Sciences, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran; Student Research Committee, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Khadijeh Dizaji Asl
- Stem Cell Research Center, Tabriz University of Medical Sciences, Tabriz, Iran; Department of Anatomical Sciences, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran; Student Research Committee, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Zeinab Mazloumi
- Stem Cell Research Center, Tabriz University of Medical Sciences, Tabriz, Iran; Student Research Committee, Tabriz University of Medical Sciences, Tabriz, Iran; Department of Applied Cell Sciences, Faculty of Advanced Medical Sciences, Tabriz University of Medical Sciences, Tabriz, Iran
| | | | - Mehdi Talebi
- Department of Applied Sciences, School of Advanced Medical Sciences, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Dariush Shanehbandi
- Immunology research center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Raheleh Farahzadi
- Hematology and Oncology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Babak Nejati
- Hematology and Oncology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
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16
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Exposure to Microbial Metabolite Butyrate Prolongs the Survival Time and Changes the Growth Pattern of Human Papillomavirus 16 E6/E7-Immortalized Keratinocytes in Vivo. THE AMERICAN JOURNAL OF PATHOLOGY 2021; 191:1822-1836. [PMID: 34214507 PMCID: PMC8579241 DOI: 10.1016/j.ajpath.2021.06.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 06/09/2021] [Accepted: 06/15/2021] [Indexed: 11/22/2022]
Abstract
Human papillomavirus (HPV) is a ubiquitous human pathogen that can be cleared by host immunity. Nonetheless, a small percentage of the patients develop persistent infection with oncogenic HPV, which poses an increased risk of developing HPV-associated malignancy. Although cell-mediated immunity is a known systemic factor, local factors that influence persistent HPV infection have not been fully investigated. HPV-related head/neck cancers have a strong site preference for the oropharynx, suggesting the existence of unique local factors that promote HPV-induced oncogenesis. The human oropharynx often harbors anaerobic bacteria that produce a variety of byproducts, including butyrate. Because butyrate is a potent epigenetic modulator, it could be an environmental factor influencing the development of HPV-positive oropharyngeal malignancy. In this study, we showed that butyrate treatment changed the property of HPV16 E6/E7-immortalized keratinocytes. In vitro, the treatment increased the cells' migration ability, slowed the growth, and increased the genotoxic resistance. When implanted in the syngeneic mice, the treated keratinocytes survived longer and exhibited a different growth pattern. The survival advantage obtained after butyrate exposure may increase the susceptibility of HPV-infected oropharyngeal keratinocytes to further malignant transformation. These results suggest that fermentation products of tonsillar bacteria may play an important role in the long-term persistence of high-risk HPV infection, which is a critical risk factor for developing HPV-positive oropharyngeal malignancy.
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17
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Diao C, Guo P, Yang W, Sun Y, Liao Y, Yan Y, Zhao A, Cai X, Hao J, Hu S, Yu W, Chen M, Wang R, Li W, Zuo Y, Pan J, Hua C, Lu X, Fan W, Zheng Z, Deng W, Luo G, Guo W. SPT6 recruits SND1 to co-activate human telomerase reverse transcriptase to promote colon cancer progression. Mol Oncol 2021; 15:1180-1202. [PMID: 33305480 PMCID: PMC8024721 DOI: 10.1002/1878-0261.12878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 10/06/2020] [Accepted: 12/09/2020] [Indexed: 12/24/2022] Open
Abstract
Human telomerase reverse transcriptase (hTERT) plays an extremely important role in cancer initiation and development, including colorectal cancer (CRC). However, the precise upstream regulatory mechanisms of hTERT in different cancer types remain poorly understood. Here, we uncovered the candidate transcriptional factor of hTERT in CRC and explored its role and the corresponding molecular mechanisms in regulating hTERT expression and CRC survival with an aim of developing mechanism-based combinational targeting therapy. The possible binding proteins at the hTERT promoter were uncovered using pull-down/mass spectrometry analysis. The regulation of SPT6 on hTERT expression and CRC survival was evaluated in human CRC cell lines and mouse models. Mechanistic studies focusing on the synergy between SPT6 and staphylococcal nuclease and Tudor domain containing 1 (SND1) in controlling hTERT expression and CRC progression were conducted also in the above two levels. The expression correlation and clinical significance of SPT6, SND1, and hTERT were investigated in tumor tissues from murine models and patients with CRC in situ. SPT6 was identified as a possible transcriptional factor to bind to the hTERT promoter. SPT6 knockdown decreased the activity of hTERT promoter, downregulated the protein expression level of hTERT, suppressed proliferation, invasion, and stem-like properties, promoted apoptosis induction, and enhanced chemotherapeutic drug sensitivity in vitro. SPT6 silencing also led to the delay of tumor growth and metastasis in mice carrying xenografts of human-derived colon cancer cells. Mechanistically, SND1 interacted with SPT6 to co-control hTERT expression and CRC cell proliferation, stemness, and growth in vitro and in vivo. SPT6, SND1, and hTERT were highly expressed simultaneously in CRC tissues, both from the murine model and patients with CRC in situ, and pairwise expression among these three factors showed a significant positive correlation. In brief, our research demonstrated that SPT6 synergized with SND1 to promote CRC development by targeting hTERT and put forward that inhibiting the SPT6-SND1-hTERT axis may create a therapeutic vulnerability in CRC.
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Affiliation(s)
- Chaoliang Diao
- Institute of Cancer Stem Cells and the First Affiliated HospitalDalian Medical UniversityChina
| | - Ping Guo
- Institute of Cancer Stem Cells and the First Affiliated HospitalDalian Medical UniversityChina
| | - Wenjing Yang
- Institute of Cancer Stem Cells and the First Affiliated HospitalDalian Medical UniversityChina
| | - Yao Sun
- Institute of Cancer Stem Cells and the First Affiliated HospitalDalian Medical UniversityChina
| | - Yina Liao
- Institute of Cancer Stem Cells and the First Affiliated HospitalDalian Medical UniversityChina
| | - Yue Yan
- State Key Laboratory of Oncology in South ChinaCollaborative Innovation Center of Cancer MedicineSun Yat‐sen University Cancer CenterGuangzhouChina
| | - Anshi Zhao
- State Key Laboratory of Oncology in South ChinaCollaborative Innovation Center of Cancer MedicineSun Yat‐sen University Cancer CenterGuangzhouChina
| | - Xin Cai
- Institute of Cancer Stem Cells and the First Affiliated HospitalDalian Medical UniversityChina
| | - Jiaojiao Hao
- Institute of Cancer Stem Cells and the First Affiliated HospitalDalian Medical UniversityChina
| | - Sheng Hu
- Institute of Cancer Stem Cells and the First Affiliated HospitalDalian Medical UniversityChina
| | - Wendan Yu
- Institute of Cancer Stem Cells and the First Affiliated HospitalDalian Medical UniversityChina
| | - Manyu Chen
- Institute of Cancer Stem Cells and the First Affiliated HospitalDalian Medical UniversityChina
| | - Ruozhu Wang
- Institute of Cancer Stem Cells and the First Affiliated HospitalDalian Medical UniversityChina
| | - Wenyang Li
- Institute of Cancer Stem Cells and the First Affiliated HospitalDalian Medical UniversityChina
| | - Yan Zuo
- Institute of Cancer Stem Cells and the First Affiliated HospitalDalian Medical UniversityChina
| | - Jinjin Pan
- Institute of Cancer Stem Cells and the First Affiliated HospitalDalian Medical UniversityChina
| | - Chunyu Hua
- Institute of Cancer Stem Cells and the First Affiliated HospitalDalian Medical UniversityChina
| | - Xiaona Lu
- Institute of Cancer Stem Cells and the First Affiliated HospitalDalian Medical UniversityChina
| | - Wenhua Fan
- State Key Laboratory of Oncology in South ChinaCollaborative Innovation Center of Cancer MedicineSun Yat‐sen University Cancer CenterGuangzhouChina
| | - Zongheng Zheng
- The Third Affiliated HospitalSun Yat‐sen UniversityGuangzhouChina
| | - Wuguo Deng
- State Key Laboratory of Oncology in South ChinaCollaborative Innovation Center of Cancer MedicineSun Yat‐sen University Cancer CenterGuangzhouChina
| | - Guangyu Luo
- State Key Laboratory of Oncology in South ChinaCollaborative Innovation Center of Cancer MedicineSun Yat‐sen University Cancer CenterGuangzhouChina
| | - Wei Guo
- Institute of Cancer Stem Cells and the First Affiliated HospitalDalian Medical UniversityChina
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18
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Goel Y, Yadav S, Pandey SK, Temre MK, Maurya BN, Verma A, Kumar A, Singh SM. Tumor Decelerating and Chemo-Potentiating Action of Methyl Jasmonate on a T Cell Lymphoma In Vivo: Role of Altered Regulation of Metabolism, Cell Survival, Drug Resistance, and Intratumoral Blood Flow. Front Oncol 2021; 11:619351. [PMID: 33718176 PMCID: PMC7947686 DOI: 10.3389/fonc.2021.619351] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Accepted: 01/18/2021] [Indexed: 12/19/2022] Open
Abstract
Methyl jasmonate (MJ), a natural oxylipin, possesses a broad spectrum of antineoplastic potential in vitro. However, its tumor growth impeding and chemo-potentiating action has not been adequately investigated in vivo. Using a murine thymus-derived tumor named Dalton’s Lymphoma (DL), in the present study, we examined if intra-tumoral administration of MJ can cause tumor growth impedance. We also explored the associated molecular mechanisms governing cell survival, carbohydrate & lipid metabolism, chemo-potentiation, and angiogenesis. MJ administration to tumor-transplanted mice caused deceleration of tumor growth accompanying prolonged survival of the tumor-bearing mice. MJ-dependent tumor growth retardation was associated with the declined blood supply in tumor milieu, cell cycle arrest, augmented induction of apoptosis and necrosis, deregulated glucose and lipid metabolism, enhanced membrane fragility of tumor cells, and altered cytokine repertoire in the tumor microenvironment. MJ administration modulated molecular network implicating Hsp70, Bcl-2, TERT, p53, Cyt c, BAX, GLUT-1, HK 2, LDH A, PDK-1, HIF-1α, ROS, MCT-1, FASN, ACSS2, SREBP1c, VEGF, cytokine repertoire, and MDR1, involved in the regulation of cell survival, carbohydrate and fatty acid metabolism, pH homeostasis, and drug resistance. Thus, the present study unveils novel molecular mechanisms of the tumor growth decelerating action of MJ. Besides, this preclinical study also establishes the adjunct therapeutic potential of MJ. Hence, the present investigation will help to design novel anti-cancer therapeutic regimens for the treatment of hematological malignancies.
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Affiliation(s)
- Yugal Goel
- School of Biotechnology, Institute of Science, Banaras Hindu University, Varanasi, India
| | - Saveg Yadav
- School of Biotechnology, Institute of Science, Banaras Hindu University, Varanasi, India
| | - Shrish Kumar Pandey
- School of Biotechnology, Institute of Science, Banaras Hindu University, Varanasi, India
| | - Mithlesh Kumar Temre
- School of Biotechnology, Institute of Science, Banaras Hindu University, Varanasi, India
| | - Babu Nandan Maurya
- Department of Radiodiagnosis and Imaging, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India
| | - Ashish Verma
- Department of Radiodiagnosis and Imaging, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India
| | - Ajay Kumar
- Department of Zoology, Institute of Science, Banaras Hindu University, Varanasi, India
| | - Sukh Mahendra Singh
- School of Biotechnology, Institute of Science, Banaras Hindu University, Varanasi, India
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19
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Sanchez-Martin V, Lopez-Pujante C, Soriano-Rodriguez M, Garcia-Salcedo JA. An Updated Focus on Quadruplex Structures as Potential Therapeutic Targets in Cancer. Int J Mol Sci 2020; 21:ijms21238900. [PMID: 33255335 PMCID: PMC7734589 DOI: 10.3390/ijms21238900] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 11/13/2020] [Accepted: 11/20/2020] [Indexed: 02/06/2023] Open
Abstract
Non-canonical, four-stranded nucleic acids secondary structures are present within regulatory regions in the human genome and transcriptome. To date, these quadruplex structures include both DNA and RNA G-quadruplexes, formed in guanine-rich sequences, and i-Motifs, found in cytosine-rich sequences, as their counterparts. Quadruplexes have been extensively associated with cancer, playing an important role in telomere maintenance and control of genetic expression of several oncogenes and tumor suppressors. Therefore, quadruplex structures are considered attractive molecular targets for cancer therapeutics with novel mechanisms of action. In this review, we provide a general overview about recent research on the implications of quadruplex structures in cancer, firstly gathering together DNA G-quadruplexes, RNA G-quadruplexes as well as DNA i-Motifs.
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Affiliation(s)
- Victoria Sanchez-Martin
- GENYO, Centre for Genomics and Oncological Research, Pfizer/University of Granada/Andalusian Regional Government, PTS Granada, 18016 Granada, Spain; (V.S.-M.); (C.L.-P.)
- Microbiology Unit, University Hospital Virgen de las Nieves, Biosanitary Research Institute IBS, Granada, 18014 Granada, Spain
- Department of Biochemistry, Molecular Biology III and Immunology, University of Granada, 18016 Granada, Spain
| | - Carmen Lopez-Pujante
- GENYO, Centre for Genomics and Oncological Research, Pfizer/University of Granada/Andalusian Regional Government, PTS Granada, 18016 Granada, Spain; (V.S.-M.); (C.L.-P.)
| | - Miguel Soriano-Rodriguez
- GENYO, Centre for Genomics and Oncological Research, Pfizer/University of Granada/Andalusian Regional Government, PTS Granada, 18016 Granada, Spain; (V.S.-M.); (C.L.-P.)
- Centre for Intensive Mediterranean Agrosystems and Agri-food Biotechnology (CIAMBITAL), University of Almeria, 04001 Almeria, Spain
- Correspondence: (M.S.-R.); (J.A.G.-S.); Tel.: +34-958715500 (M.S.-R.); +34-958715500 (J.A.G.-S.)
| | - Jose A. Garcia-Salcedo
- GENYO, Centre for Genomics and Oncological Research, Pfizer/University of Granada/Andalusian Regional Government, PTS Granada, 18016 Granada, Spain; (V.S.-M.); (C.L.-P.)
- Microbiology Unit, University Hospital Virgen de las Nieves, Biosanitary Research Institute IBS, Granada, 18014 Granada, Spain
- Correspondence: (M.S.-R.); (J.A.G.-S.); Tel.: +34-958715500 (M.S.-R.); +34-958715500 (J.A.G.-S.)
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Eslami SS, Jafari D, Montazeri H, Sadeghizadeh M, Tarighi P. Combination of Curcumin and Metformin Inhibits Cell Growth and Induces Apoptosis without Affecting the Cell Cycle in LNCaP Prostate Cancer Cell Line. Nutr Cancer 2020; 73:1026-1039. [PMID: 32657143 DOI: 10.1080/01635581.2020.1783327] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Side effects and chemotherapy resistance, demand new therapeutics with minimal side effects. Here, we investigated the combined effect of curcumin and metformin on the LNCaP prostate cancer cell line. LNCaP cells were treated with curcumin, metformin, and their combination at different concentrations. Cell viability was assessed by MTT assay and expression of Bax, Bcl-2, mTOR, hTERT, PUMA, p53 and p21 genes was analyzed by real-time PCR. Apoptosis and cell cycle were assessed by flow cytometry. Our results revealed that the viability of cells treated with curcumin, metformin, and their combination was significantly (P < 0.05) reduced with increasing the concentration and prolonging the treatment time. Meanwhile, the combination showed a synergistic effect within 48 h. In the curcumin treated group, the expression of Bcl-2 and hTERT genes diminished. In the metformin treated group, the expression of Bax and PUMA genes was enhanced while the expression of Bcl-2, hTERT, mTOR, and p53 genes declined. Although all treatments induced apoptosis, the combination of curcumin and metformin showed the maximum level of apoptosis, cytotoxicity, and expression of Bax gene. The combination of curcumin and metformin showed synergistic effects within 48 h. This combination could be a potential therapeutic candidate for prostate cancer to be further investigated.
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Affiliation(s)
- Seyed Sadegh Eslami
- Department of Medical Biotechnology, Faculty of Allied Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Davod Jafari
- Department of Medical Biotechnology, Faculty of Allied Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Hamed Montazeri
- School of Pharmacy-International Campus, Iran University of Medical Sciences, Tehran, Iran
| | - Majid Sadeghizadeh
- Department of Molecular Genetics, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran
| | - Parastoo Tarighi
- Department of Medical Biotechnology, Faculty of Allied Medicine, Iran University of Medical Sciences, Tehran, Iran
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21
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Rosen J, Jakobs P, Ale-Agha N, Altschmied J, Haendeler J. Non-canonical functions of Telomerase Reverse Transcriptase - Impact on redox homeostasis. Redox Biol 2020; 34:101543. [PMID: 32502898 PMCID: PMC7267725 DOI: 10.1016/j.redox.2020.101543] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 04/11/2020] [Accepted: 04/13/2020] [Indexed: 02/08/2023] Open
Abstract
Telomerase consists of the catalytic subunit Telomerase Reverse Transcriptase (TERT) and the Telomerase RNA Component. Its canonical function is the prevention of telomere erosion. Over the last years it became evident that TERT is also present in tissues with low replicative potential. Important non-canonical functions of TERT are protection against apoptosis and maintenance of the cellular redox homeostasis in cancer as well as in somatic tissues. Intriguingly, TERT and reactive oxygen species (ROS) are interdependent on each other, with TERT being regulated by changes in the redox balance and itself controlling ROS levels in the cytosol and in the mitochondria. The latter is achieved because TERT is present in the mitochondria, where it protects mitochondrial DNA and maintains levels of anti-oxidative enzymes. Since numerous diseases are associated with oxidative stress, increasing the mitochondrial TERT level could be of therapeutic value.
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Affiliation(s)
- Julia Rosen
- Environmentally-induced Cardiovascular Degeneration, Institute of Clinical Chemistry and Laboratory Diagnostics, Medical Faculty, Heinrich-Heine University Düsseldorf, Germany; IUF-Leibniz Research Institute for Environmental Medicine, Düsseldorf, Germany
| | - Philipp Jakobs
- Environmentally-induced Cardiovascular Degeneration, Institute of Clinical Chemistry and Laboratory Diagnostics, Medical Faculty, Heinrich-Heine University Düsseldorf, Germany; IUF-Leibniz Research Institute for Environmental Medicine, Düsseldorf, Germany
| | - Niloofar Ale-Agha
- Environmentally-induced Cardiovascular Degeneration, Institute of Clinical Chemistry and Laboratory Diagnostics, Medical Faculty, Heinrich-Heine University Düsseldorf, Germany; IUF-Leibniz Research Institute for Environmental Medicine, Düsseldorf, Germany
| | - Joachim Altschmied
- IUF-Leibniz Research Institute for Environmental Medicine, Düsseldorf, Germany.
| | - Judith Haendeler
- Environmentally-induced Cardiovascular Degeneration, Institute of Clinical Chemistry and Laboratory Diagnostics, Medical Faculty, Heinrich-Heine University Düsseldorf, Germany; IUF-Leibniz Research Institute for Environmental Medicine, Düsseldorf, Germany.
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22
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D’Aguanno S, Del Bufalo D. Inhibition of Anti-Apoptotic Bcl-2 Proteins in Preclinical and Clinical Studies: Current Overview in Cancer. Cells 2020; 9:cells9051287. [PMID: 32455818 PMCID: PMC7291206 DOI: 10.3390/cells9051287] [Citation(s) in RCA: 77] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 05/18/2020] [Accepted: 05/19/2020] [Indexed: 12/30/2022] Open
Abstract
The dynamic interplay between pro-death and pro-survival Bcl-2 family proteins is responsible for a cell’s fate. Due to the recognized relevance of this family in cancer progression and response to therapy, different efforts have made in recent years in order to develop small molecules able to target anti-apoptotic proteins such as Bcl-2, Bcl-xL and Mcl-1. The limitations of the first Bcl-2 family targeted drugs, regarding on-target and off-target toxicities, have been overcome with the development of venetoclax (ABT-199), the first BH3 mimetic inhibitor approved by the FDA. The purpose of this review is to discuss the state-of-the-art in the development of drugs targeting Bcl-2 anti-apoptotic proteins and to highlight the potential of their application as single agents or in combination for improving anti-cancer therapy, focusing in particular on solid tumors.
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23
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Asamitsu S, Shioda N, Sugiyama H. Switching Off Cancer-Causing Telomerase Using Small Molecules. Cell Chem Biol 2020; 26:1045-1047. [PMID: 31419416 DOI: 10.1016/j.chembiol.2019.08.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Aberrant telomerase activity via the expression of its catalytic subunit hTERT is a hallmark of some malignant cancers. In this issue of Cell Chemical Biology, Song et al. (2019) demonstrate that hTERT downregulation by targeting a repressive DNA motif on the gene promoter using small molecules effectively kills cancer cells.
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Affiliation(s)
- Sefan Asamitsu
- Department of Genomic Neurology, Institute of Molecular Embryology and Genetics (IMEG), Kumamoto University, Kumamoto 8600811, Japan
| | - Norifumi Shioda
- Department of Genomic Neurology, Institute of Molecular Embryology and Genetics (IMEG), Kumamoto University, Kumamoto 8600811, Japan
| | - Hiroshi Sugiyama
- Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto 6068502, Japan; Institute for Integrated Cell-Material Sciences (iCeMS), Kyoto University, Kyoto 6068501, Japan.
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Thompson CA, Wong JM. Non-canonical Functions of Telomerase Reverse Transcriptase: Emerging Roles and Biological Relevance. Curr Top Med Chem 2020; 20:498-507. [DOI: 10.2174/1568026620666200131125110] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Revised: 01/10/2020] [Accepted: 01/21/2020] [Indexed: 12/11/2022]
Abstract
Increasing evidence from research on telomerase suggests that in addition to its catalytic telomere
repeat synthesis activity, telomerase may have other biologically important functions. The canonical
roles of telomerase are at the telomere ends where they elongate telomeres and maintain genomic
stability and cellular lifespan. The catalytic protein component Telomerase Reverse Transcriptase
(TERT) is preferentially expressed at high levels in cancer cells despite the existence of an alternative
mechanism for telomere maintenance (alternative lengthening of telomeres or ALT). TERT is also expressed
at higher levels than necessary for maintaining functional telomere length, suggesting other possible
adaptive functions. Emerging non-canonical roles of TERT include regulation of non-telomeric
DNA damage responses, promotion of cell growth and proliferation, acceleration of cell cycle kinetics,
and control of mitochondrial integrity following oxidative stress. Non-canonical activities of TERT primarily
show cellular protective effects, and nuclear TERT has been shown to protect against cell death
following double-stranded DNA damage, independent of its role in telomere length maintenance. TERT
has been suggested to act as a chromatin modulator and participate in the transcriptional regulation of
gene expression. TERT has also been reported to regulate transcript levels through an RNA-dependent
RNA Polymerase (RdRP) activity and produce siRNAs in a Dicer-dependent manner. At the mitochondria,
TERT is suggested to protect against oxidative stress-induced mtDNA damage and promote mitochondrial
integrity. These extra-telomeric functions of TERT may be advantageous in the context of increased
proliferation and metabolic stress often found in rapidly-dividing cancer cells. Understanding
the spectrum of non-canonical functions of telomerase may have important implications for the rational
design of anti-cancer chemotherapeutic drugs.
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Affiliation(s)
- Connor A.H. Thompson
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, V6T 1Z3, Canada
| | - Judy M.Y. Wong
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, V6T 1Z3, Canada
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25
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Ding X, Liu X, Wang F, Wang F, Geng X. Role of Senescence and Neuroprotective Effects of Telomerase in Neurodegenerative Diseases. Rejuvenation Res 2020; 23:150-158. [DOI: 10.1089/rej.2018.2115] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Affiliation(s)
- Xuelu Ding
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Tianjin Medical University, Tianjin, China
- Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), Tianjin Medical University, Tianjin, China
| | - Xuewen Liu
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Tianjin Medical University, Tianjin, China
- Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), Tianjin Medical University, Tianjin, China
| | - Feng Wang
- Department of Genetics, School of Basic Medical Sciences, Tianjin Medical University, Tianjin, China
| | - Fei Wang
- Department of Neurology, General Hospital, Tianjin Medical University, Tianjin, China
| | - Xin Geng
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Tianjin Medical University, Tianjin, China
- Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), Tianjin Medical University, Tianjin, China
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26
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Smith-Sonneborn J. Telomerase Biology Associations Offer Keys to Cancer and Aging Therapeutics. Curr Aging Sci 2020; 13:11-21. [PMID: 31544708 PMCID: PMC7403649 DOI: 10.2174/1874609812666190620124324] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Revised: 05/07/2019] [Accepted: 05/24/2019] [Indexed: 02/07/2023]
Abstract
BACKGROUND Although telomerase has potential for age-related disease intervention, the overexpression of telomerase in about 90% of cancers, and in HIV virus reservoirs, cautions against se in anti-aging telomerase therapeutics. While multiple reviews document the canonical function of telomerase for maintenance of telomeres, as well as an increasing numbers of reviews that reveal new non-canonical functions of telomerase, there was no systematic review that focuses on the array of associates of the subunit of Telomerase Reverse transcriptase protein (TERT) as pieces of the puzzle to assemble a picture of the how specific TERT complexes uniquely impact aging and age-related diseases and more can be expected. METHODS A structured search of bibliographic data on TERT complexes was undertaken using databases from the National Center for Biotechnology Information Pubmed with extensive access to biomedical and genomic information in order to obtain a unique documented and cited overview of TERT complexes that may uniquely impact aging and age-related diseases. RESULTS The TERT associations include proper folding, intracellular TERT transport, metabolism, mitochondrial ROS (Reactive Oxygen Species) regulation, inflammation, cell division, cell death, and gene expression, in addition to the well-known telomere maintenance. While increase of cell cycle inhibitors promote aging, in cancer, the cell cycle check-point regulators are ambushed in favor of cell proliferation, while cytoplasmic TERT protects a cell cycle inhibitor in oxidative stress. The oncogene cMyc regulates gene expression for overexpression of TERT, and reduction of cell cycle inhibitors-the perfect storm for cancer promotion. TERT binds with the oncogene RMRP RNA, and TERT-RMRP function can regulate levels of that oncogene RNA, and TERT in a TBN complex can regulate heterochromatin. Telomerase benefit and novel function in neurology and cardiology studies open new anti- aging hope. GV1001, a 16 amino acid peptide of TERT that associates with Heat Shock Proteins (HSP's), bypasses the cell membrane with remarkable anti disease potential. CONCLUSIONS TERT "associates" are anti-cancer targets for downregulation, but upregulation in antiaging therapy. The overview revealed that unique TERT associations that impact all seven pillars of aging identified by the Trans-NIH Geroscience Initiative that influence aging and urge research for appropriate targeted telomerase supplements/ stimulation, and inclusion in National Institute on Aging Intervention Testing Program. The preference for use of available "smart drugs", targeted to only cancer, not off-target anti- aging telomerase is implied by the multiplicity of TERT associates functions.
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Affiliation(s)
- Joan Smith-Sonneborn
- Department Zoology and Physiology, University of Wyoming, Laramie, Wyoming, WY, USA
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27
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Platella C, Raucci U, Rega N, D'Atri S, Levati L, Roviello GN, Fuggetta MP, Musumeci D, Montesarchio D. Shedding light on the interaction of polydatin and resveratrol with G-quadruplex and duplex DNA: a biophysical, computational and biological approach. Int J Biol Macromol 2019; 151:1163-1172. [PMID: 31747572 DOI: 10.1016/j.ijbiomac.2019.10.160] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Revised: 10/09/2019] [Accepted: 10/18/2019] [Indexed: 12/17/2022]
Abstract
Among polyphenols, trans-resveratrol (tRES) and trans-polydatin (tPD) exert multiple biological effects, particularly antioxidant and antiproliferative. In this work, we have investigated the interaction of tPD with three cancer-related DNA sequences able to form G-quadruplex (G4) structures, as well as with a model duplex, and compared its behaviour with tRES. Interestingly, fluorescence analysis evidenced the ability of tPD to bind all the studied DNA systems, similarly to tRES, with tRES displaying a higher ability to discriminate G4 over duplex with respect to tPD. However, neither tRES nor tPD produced significant conformational changes of the analyzed DNA upon binding, as determined by CD-titration analysis. Computational analysis and biological data confirmed the biophysical results: indeed, molecular docking evidenced the stronger interaction of tRES with the promoter of c-myc oncogene, and immunoblotting assays revealed a reduction of c-myc expression, more effective for tRES than tPD. Furthermore, in vitro assays on melanoma cells proved that tPD was able to significantly reduce telomerase activity, and inhibit cell proliferation, with tRES producing higher effects than tPD.
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Affiliation(s)
- Chiara Platella
- Department of Chemical Sciences, University of Naples Federico II, Via Cintia 21, Naples I-80126, Italy
| | - Umberto Raucci
- Department of Chemical Sciences, University of Naples Federico II, Via Cintia 21, Naples I-80126, Italy
| | - Nadia Rega
- Department of Chemical Sciences, University of Naples Federico II, Via Cintia 21, Naples I-80126, Italy; Interdisciplinary Research Centre on Biomaterials (CRIB), University of Naples Federico II, Piazzale Tecchio 80, Naples I-80125, Italy
| | - Stefania D'Atri
- Laboratory of Molecular Oncology, IDI-IRCCS, Via dei Monti di Creta 104, Rome I-00167, Italy
| | - Lauretta Levati
- Laboratory of Molecular Oncology, IDI-IRCCS, Via dei Monti di Creta 104, Rome I-00167, Italy
| | - Giovanni N Roviello
- Institute of Biostructures and Bioimages, CNR, Via Mezzocannone 16, Naples I-80134, Italy
| | - Maria Pia Fuggetta
- Institute of Translational Pharmacology, CNR, Via Fosso del Cavaliere 100, Rome I-00133, Italy.
| | - Domenica Musumeci
- Department of Chemical Sciences, University of Naples Federico II, Via Cintia 21, Naples I-80126, Italy; Institute of Biostructures and Bioimages, CNR, Via Mezzocannone 16, Naples I-80134, Italy.
| | - Daniela Montesarchio
- Department of Chemical Sciences, University of Naples Federico II, Via Cintia 21, Naples I-80126, Italy
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Inhibition of PI3K pathway using BKM120 intensified the chemo-sensitivity of breast cancer cells to arsenic trioxide (ATO). Int J Biochem Cell Biol 2019; 116:105615. [DOI: 10.1016/j.biocel.2019.105615] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2019] [Revised: 09/05/2019] [Accepted: 09/16/2019] [Indexed: 12/12/2022]
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Perera ON, Sobinoff AP, Teber ET, Harman A, Maritz MF, Yang SF, Pickett HA, Cesare AJ, Arthur JW, MacKenzie KL, Bryan TM. Telomerase promotes formation of a telomere protective complex in cancer cells. SCIENCE ADVANCES 2019; 5:eaav4409. [PMID: 31616780 PMCID: PMC6774720 DOI: 10.1126/sciadv.aav4409] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2018] [Accepted: 09/09/2019] [Indexed: 05/04/2023]
Abstract
Telomerase is a ribonucleoprotein complex that catalyzes addition of telomeric DNA repeats to maintain telomeres in replicating cells. Here, we demonstrate that the telomerase protein hTERT performs an additional role at telomeres that is independent of telomerase catalytic activity yet essential for telomere integrity and cell proliferation. Short-term depletion of endogenous hTERT reduced the levels of heat shock protein 70 (Hsp70-1) and the telomere protective protein Apollo at telomeres, and induced telomere deprotection and cell cycle arrest, in the absence of telomere shortening. Short-term expression of hTERT promoted colocalization of Hsp70-1 with telomeres and Apollo and reduced numbers of deprotected telomeres, in a manner independent of telomerase catalytic activity. These data reveal a previously unidentified noncanonical function of hTERT that promotes formation of a telomere protective complex containing Hsp70-1 and Apollo and is essential for sustained proliferation of telomerase-positive cancer cells, likely contributing to the known cancer-promoting effects of both hTERT and Hsp70-1.
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Affiliation(s)
- Omesha N. Perera
- Cell Biology Unit, Children’s Medical Research Institute, Faculty of Medicine and Health, University of Sydney, Westmead, NSW 2145, Australia
| | - Alexander P. Sobinoff
- Telomere Length Regulation Unit, Children’s Medical Research Institute, Faculty of Medicine and Health, University of Sydney, Westmead, NSW 2145, Australia
| | - Erdahl T. Teber
- Bioinformatics Unit, Children’s Medical Research Institute, Faculty of Medicine and Health, University of Sydney, Westmead, NSW 2145, Australia
| | - Ashley Harman
- Cell Biology Unit, Children’s Medical Research Institute, Faculty of Medicine and Health, University of Sydney, Westmead, NSW 2145, Australia
| | - Michelle F. Maritz
- Children’s Cancer Institute, School of Women’s and Children’s Health, University of NSW, NSW 2052, Australia
| | - Sile F. Yang
- Telomere Length Regulation Unit, Children’s Medical Research Institute, Faculty of Medicine and Health, University of Sydney, Westmead, NSW 2145, Australia
| | - Hilda A. Pickett
- Telomere Length Regulation Unit, Children’s Medical Research Institute, Faculty of Medicine and Health, University of Sydney, Westmead, NSW 2145, Australia
| | - Anthony J. Cesare
- Genome Integrity Unit, Children’s Medical Research Institute, Faculty of Medicine and Health, University of Sydney, Westmead, NSW 2145, Australia
| | - Jonathan W. Arthur
- Bioinformatics Unit, Children’s Medical Research Institute, Faculty of Medicine and Health, University of Sydney, Westmead, NSW 2145, Australia
| | - Karen L. MacKenzie
- Children’s Cancer Institute, School of Women’s and Children’s Health, University of NSW, NSW 2052, Australia
| | - Tracy M. Bryan
- Cell Biology Unit, Children’s Medical Research Institute, Faculty of Medicine and Health, University of Sydney, Westmead, NSW 2145, Australia
- Corresponding author.
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Song JH, Kang HJ, Luevano LA, Gokhale V, Wu K, Pandey R, Sherry Chow HH, Hurley LH, Kraft AS. Small-Molecule-Targeting Hairpin Loop of hTERT Promoter G-Quadruplex Induces Cancer Cell Death. Cell Chem Biol 2019; 26:1110-1121.e4. [PMID: 31155510 PMCID: PMC6713458 DOI: 10.1016/j.chembiol.2019.04.009] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 01/28/2019] [Accepted: 04/16/2019] [Indexed: 12/23/2022]
Abstract
Increased telomerase activity is associated with malignancy and poor prognosis in human cancer, but the development of targeted agents has not yet provided clinical benefit. Here we report that, instead of targeting the telomerase enzyme directly, small molecules that bind to the G-hairpin of the hTERT G-quadruplex-forming sequence kill selectively malignant cells without altering the function of normal cells. RG260 targets the hTERT G-quadruplex stem-loop folding but not tetrad DNAs, leading to downregulation of hTERT expression. To improve physicochemical and pharmacokinetic properties, we derived a small-molecule analog, RG1603, from the parent compound. RG1603 induces mitochondrial defects including PGC1α and NRF2 inhibition and increases oxidative stress, followed by DNA damage and apoptosis. RG1603 injected as a single agent has tolerable toxicity while achieving strong anticancer efficacy in a tumor xenograft mouse model. These results demonstrate a unique approach to inhibiting the hTERT that functions by impairing mitochondrial activity, inducing cell death.
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Affiliation(s)
- Jin H Song
- Department of Cellular and Molecular Medicine, University of Arizona, 1515 North Campbell Avenue, Tucson, AZ 85724, USA; University of Arizona Cancer Center, 1515 North Campbell Avenue, Tucson, AZ 85724, USA.
| | - Hyun-Jin Kang
- College of Pharmacy, University of Arizona, 1703 East Mabel Street, Tucson, AZ 85721, USA; Reglagene LLC, 1703 East Mabel Street, Tucson, AZ 85721, USA
| | - Libia A Luevano
- University of Arizona Cancer Center, 1515 North Campbell Avenue, Tucson, AZ 85724, USA
| | - Vijay Gokhale
- Reglagene LLC, 1703 East Mabel Street, Tucson, AZ 85721, USA; BIO5 Institute, University of Arizona, 1657 East Helen Street, Tucson, AZ 85721, USA
| | - Kui Wu
- College of Pharmacy, University of Arizona, 1703 East Mabel Street, Tucson, AZ 85721, USA
| | - Ritu Pandey
- Department of Cellular and Molecular Medicine, University of Arizona, 1515 North Campbell Avenue, Tucson, AZ 85724, USA; University of Arizona Cancer Center, 1515 North Campbell Avenue, Tucson, AZ 85724, USA
| | - H-H Sherry Chow
- University of Arizona Cancer Center, 1515 North Campbell Avenue, Tucson, AZ 85724, USA
| | - Laurence H Hurley
- College of Pharmacy, University of Arizona, 1703 East Mabel Street, Tucson, AZ 85721, USA; Reglagene LLC, 1703 East Mabel Street, Tucson, AZ 85721, USA.
| | - Andrew S Kraft
- University of Arizona Cancer Center, 1515 North Campbell Avenue, Tucson, AZ 85724, USA.
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Fuggetta MP, Spanu P, Ulgheri F, Deligia F, Carta P, Mannu A, Trotta V, De Cicco R, Barra A, Zona E, Morelli F. A New Synthetic Spiroketal: Studies on Antitumor Activity on Murine Melanoma Model In Vivo and Mechanism of Action In Vitro. Anticancer Agents Med Chem 2019; 19:567-578. [PMID: 30706794 DOI: 10.2174/1871520619666190131141400] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Revised: 11/05/2018] [Accepted: 01/19/2019] [Indexed: 11/22/2022]
Abstract
BACKGROUND In a previous study, we synthesised a new spiroketal derivative, inspired to natural products, that has shown high antiproliferative activity, potent telomerase inhibition and proapoptotic activity on several human cell lines. OBJECTIVE This work focused on the study of in vivo antitumor effect of this synthetic spiroketal on a murine melanoma model. In order to shed additional light on the origin of the antitumor effect, in vitro studies were performed. METHODS Spiroketal was administered to B16F10 melanoma mice at a dose of 5 mg/Kg body weight via intraperitoneum at alternate days for 15 days. Tumor volume measures were made every 2 days starting after 12 days from cells injection. The effects of the spiroketal on tumor growth inhibition, apoptosis induction, and cell cycle modification were investigated in vitro on B16 cells. HIF1α gene expression, the inhibition of cells migration and the changes induced in cytoskeleton conformation were evaluated. RESULTS Spiroketal displayed proapoptotic activity and high antitumor activity in B16 cells with nanomolar IC50. Moreover it has shown to inhibit cell migration, to strongly reduce the HIF1α expression and to induce strongly deterioration of cytoskeleton structure. A potent dose-dependent antitumor efficacy in syngenic B16/C57BL/6J murine model of melanoma was observed with the suppression of tumor growth by an average of 90% at a dose of 5 mg/kg. CONCLUSION The synthesized spiroketal shows high antitumor activity in the B16 cells in vitro at nM concentration and a dose-dependent antitumor efficacy in syngenic B16/C57BL/6J mice. The results suggest that this natural product inspired spiroketal may have a potential application in melanoma therapy.
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Affiliation(s)
- Maria P Fuggetta
- Istituto di Farmacologia Traslazionale-Consiglio Nazionale delle Ricerche, Roma, Italy
| | - Pietro Spanu
- Istituto di Chimica Biomolecolare- Consiglio Nazionale delle Ricerche, Sassari, Italy
| | - Fausta Ulgheri
- Istituto di Chimica Biomolecolare- Consiglio Nazionale delle Ricerche, Sassari, Italy
| | - Francesco Deligia
- Istituto di Chimica Biomolecolare- Consiglio Nazionale delle Ricerche, Sassari, Italy
| | - Paola Carta
- Istituto di Chimica Biomolecolare- Consiglio Nazionale delle Ricerche, Sassari, Italy
| | - Alberto Mannu
- Istituto di Chimica Biomolecolare- Consiglio Nazionale delle Ricerche, Sassari, Italy
| | - Veronica Trotta
- Istituto di Genetica e Biofisica A. Buzzati Traverso-Consiglio Nazionale delle Ricerche, Napoli, Italy
| | - Rosanna De Cicco
- Istituto di Genetica e Biofisica A. Buzzati Traverso-Consiglio Nazionale delle Ricerche, Napoli, Italy
| | - Adriano Barra
- Istituto di Genetica e Biofisica A. Buzzati Traverso-Consiglio Nazionale delle Ricerche, Napoli, Italy
| | - Enrica Zona
- Istituto di Genetica e Biofisica A. Buzzati Traverso-Consiglio Nazionale delle Ricerche, Napoli, Italy
| | - Franco Morelli
- Istituto di Genetica e Biofisica A. Buzzati Traverso-Consiglio Nazionale delle Ricerche, Napoli, Italy
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32
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Asamitsu S, Obata S, Yu Z, Bando T, Sugiyama H. Recent Progress of Targeted G-Quadruplex-Preferred Ligands Toward Cancer Therapy. Molecules 2019; 24:E429. [PMID: 30682877 PMCID: PMC6384606 DOI: 10.3390/molecules24030429] [Citation(s) in RCA: 208] [Impact Index Per Article: 34.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Revised: 01/22/2019] [Accepted: 01/23/2019] [Indexed: 02/07/2023] Open
Abstract
A G-quadruplex (G4) is a well-known nucleic acid secondary structure comprising guanine-rich sequences, and has profound implications for various pharmacological and biological events, including cancers. Therefore, ligands interacting with G4s have attracted great attention as potential anticancer therapies or in molecular probe applications. To date, a large variety of DNA/RNA G4 ligands have been developed by a number of laboratories. As protein-targeting drugs face similar situations, G-quadruplex-interacting drugs displayed low selectivity to the targeted G-quadruplex structure. This low selectivity could cause unexpected effects that are usually reasons to halt the drug development process. In this review, we address the recent research on synthetic G4 DNA-interacting ligands that allow targeting of selected G4s as an approach toward the discovery of highly effective anticancer drugs.
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Affiliation(s)
- Sefan Asamitsu
- Department of Chemistry, Graduate School of Science Kyoto University, Kitashirakawa-Oiwakecho, Sakyo, Kyoto, 606-8502, Japan.
| | - Shunsuke Obata
- Department of Chemistry, Graduate School of Science Kyoto University, Kitashirakawa-Oiwakecho, Sakyo, Kyoto, 606-8502, Japan.
| | - Zutao Yu
- Department of Chemistry, Graduate School of Science Kyoto University, Kitashirakawa-Oiwakecho, Sakyo, Kyoto, 606-8502, Japan.
| | - Toshikazu Bando
- Department of Chemistry, Graduate School of Science Kyoto University, Kitashirakawa-Oiwakecho, Sakyo, Kyoto, 606-8502, Japan.
| | - Hiroshi Sugiyama
- Department of Chemistry, Graduate School of Science Kyoto University, Kitashirakawa-Oiwakecho, Sakyo, Kyoto, 606-8502, Japan.
- Institute for Integrated Cell-Material Science (WPI-iCeMS) Kyoto University, Yoshida-Ushinomiyacho, Sakyo, Kyoto, 606-8501, Japan.
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33
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Jin Y, You L, Kim HJ, Lee HW. Telomerase Reverse Transcriptase Contains a BH3-Like Motif and Interacts with BCL-2 Family Members. Mol Cells 2018; 41:684-694. [PMID: 29937479 PMCID: PMC6078858 DOI: 10.14348/molcells.2018.0206] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2018] [Accepted: 05/21/2018] [Indexed: 12/12/2022] Open
Abstract
Upregulation of human telomerase reverse transcriptase (hTERT) expression is an important factor in the cellular survival and cancer. Although growing evidence suggests that hTERT inhibits cellular apoptosis by telomere-independent functions, the mechanisms involved are not fully understood. Here, we show that hTERT contains a BH3-like motif, a short peptide sequence found in BCL-2 family proteins, and interacts with anti-apoptotic BCL-2 family proteins MCL-1 and BCL-xL, suggesting a functional link between hTERT and the mitochondrial pathway of apoptosis. Additionally, we propose that hTERT can be categorized into the atypical BH3-only proteins that promote cellular survival, possibly due to the non-canonical interaction between hTERT and antiapoptotic proteins. Although the detailed mechanisms underlying the hTERT BH3-like motif functions and interactions between hTERT and BCL-2 family proteins have not been elucidated, this work proposes a possible connection between hTERT and BCL-2 family members and reconsiders the role of the BH3-like motif as an interaction motif.
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Affiliation(s)
- Young Jin
- Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, Seoul 03722,
Korea
| | - Long You
- Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, Seoul 03722,
Korea
| | - Hye Jeong Kim
- Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, Seoul 03722,
Korea
| | - Han-Woong Lee
- Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, Seoul 03722,
Korea
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34
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Wang J, Zhang MY, Xu SQ, Cheng J, Yu ZJ, Hu XM. Down-regulation of telomerase reverse transcriptase-related anti-apoptotic function in a rat model of acrylamide induced neurobehavioral deficits. Biotech Histochem 2018; 93:512-518. [PMID: 29926741 DOI: 10.1080/10520295.2018.1471523] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
Abstract
Although the precise mechanism is unknown, neuron apoptosis is believed to participate in neuropathy caused by acrylamide (ACR). Telomerase reverse transcriptase (TERT) exhibits an anti-apoptotic function, but its contribution to the pathogenesis of ACR neurotoxicity is unclear. We investigated adult male rats that were given 30, 40 and 50 mg/kg ACR three times/week for 4 weeks. We found that ACR treatment caused significant deficits in sensory/motor function as measured by gait score, landing foot spread distance, movement initiation test and tail immersion test. Histological examination showed that the cerebral cortex in all ACR treated animals exhibited fewer neurons and more condensed nuclei than normal cortex. A significant increase in apoptosis was found in the cerebral cortex of rat brains subjected to ACR treatment in a dose-dependent manner. The expression of TERT in the brain was significantly reduced by ACR treatment. The pro-apoptotic cleaved caspase-3 protein level was increased, while the anti-apoptotic Bcl-2 protein level was decreased by 30 - 50 mg/kg ACR. Our findings indicate that TERT and its downstream regulators of neuron apoptosis, including Bcl-2 and cleaved caspase-3, were involved in ACR neurotoxicity.
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Affiliation(s)
- J Wang
- a Department of Pharmacy , College of Medicine, Wuhan University of Science and Technology , Wuhan.,b Hubei Province Key Laboratory of Occupational Hazard Identification and Control , Wuhan University of Science and Technology , Wuhan
| | - M Y Zhang
- a Department of Pharmacy , College of Medicine, Wuhan University of Science and Technology , Wuhan.,b Hubei Province Key Laboratory of Occupational Hazard Identification and Control , Wuhan University of Science and Technology , Wuhan
| | - S Q Xu
- a Department of Pharmacy , College of Medicine, Wuhan University of Science and Technology , Wuhan.,b Hubei Province Key Laboratory of Occupational Hazard Identification and Control , Wuhan University of Science and Technology , Wuhan
| | - J Cheng
- a Department of Pharmacy , College of Medicine, Wuhan University of Science and Technology , Wuhan.,b Hubei Province Key Laboratory of Occupational Hazard Identification and Control , Wuhan University of Science and Technology , Wuhan
| | - Z J Yu
- a Department of Pharmacy , College of Medicine, Wuhan University of Science and Technology , Wuhan.,b Hubei Province Key Laboratory of Occupational Hazard Identification and Control , Wuhan University of Science and Technology , Wuhan
| | - X M Hu
- a Department of Pharmacy , College of Medicine, Wuhan University of Science and Technology , Wuhan.,b Hubei Province Key Laboratory of Occupational Hazard Identification and Control , Wuhan University of Science and Technology , Wuhan.,c College of Pharmacy , Shanghai University of Medicine & Health Sciences , Shanghai , China
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Dinami R, Buemi V, Sestito R, Zappone A, Ciani Y, Mano M, Petti E, Sacconi A, Blandino G, Giacca M, Piazza S, Benetti R, Schoeftner S. Epigenetic silencing of miR-296 and miR-512 ensures hTERT dependent apoptosis protection and telomere maintenance in basal-type breast cancer cells. Oncotarget 2017; 8:95674-95691. [PMID: 29221158 PMCID: PMC5707052 DOI: 10.18632/oncotarget.21180] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Accepted: 08/27/2017] [Indexed: 12/31/2022] Open
Abstract
The catalytic subunit of the telomerase complex, hTERT, ensures unlimited proliferative potential of cancer cells by maintaining telomere function and protecting from apoptosis. Using a miRNA screening approach we identified miR-296-5p and miR-512-5p as miRNAs that target hTERT in breast cancer cells. Ectopic miR-296-5p and miR-512-5p reduce telomerase activity, drive telomere shortening and cause proliferation defects by enhancing senescence and apoptosis in breast cancer cells. In line with the relevance of hTERT expression for human cancer we found that miR-296-5p and miR-512-5p expression is reduced in human breast cancer. Accordingly, high expression of miR-296-5p and miR-512-5p target genes including hTERT is linked with significantly reduced distant metastasis free survival and relapse free survival of basal type breast cancer patients. This suggests relevance of the identified miRNAs in basal type breast cancer. Epigenetic silencing of miR-296 and miR-512 encoding genes is responsible for low levels of miR-296-5p and miR-512-5p expression in basal type breast cancer cells. Disrupting gene silencing results in a dramatic upregulation of miR-296-5p and miR-512-5p levels leading to reduced hTERT expression and increased sensitivity to the induction of apoptosis. Altogether, our data suggest that epigenetic regulatory circuits in basal type breast cancer may contribute to high hTERT levels by silencing miR-296-5p and miR-512-5p expression, thereby contributing to the aggressiveness of basal type breast cancer.
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Affiliation(s)
- Roberto Dinami
- Laboratorio Nazionale Consorzio Interuniversitario Biotecnologie (LNCIB), Genomic Stability Unit, Trieste 34149, Italy.,Italian National Cancer Institute, Regina Elena, Rome 00144, Italy
| | - Valentina Buemi
- Laboratorio Nazionale Consorzio Interuniversitario Biotecnologie (LNCIB), Genomic Stability Unit, Trieste 34149, Italy.,Department of Life Sciences, Università degli Studi di Trieste, Trieste 34127, Italy
| | - Rosanna Sestito
- Italian National Cancer Institute, Regina Elena, Rome 00144, Italy
| | - Antonina Zappone
- Laboratorio Nazionale Consorzio Interuniversitario Biotecnologie (LNCIB), Genomic Stability Unit, Trieste 34149, Italy.,Department of Life Sciences, Università degli Studi di Trieste, Trieste 34127, Italy
| | - Yari Ciani
- Laboratorio Nazionale Consorzio Interuniversitario Biotecnologie (LNCIB), Bioinformatics and Functional Genomics Unit (BFGU), Trieste 34149, Italy
| | - Miguel Mano
- International Centre for Genetic Engineering and Biotechnology (ICGEB), Molecular Medicine Laboratory, Trieste 34149, Italy
| | - Eleonora Petti
- Laboratorio Nazionale Consorzio Interuniversitario Biotecnologie (LNCIB), Genomic Stability Unit, Trieste 34149, Italy.,Italian National Cancer Institute, Regina Elena, Rome 00144, Italy.,Department of Life Sciences, Università degli Studi di Trieste, Trieste 34127, Italy
| | - Andrea Sacconi
- Italian National Cancer Institute, Regina Elena, Translational Oncogenomics Group, Rome 00144, Italy
| | - Giovanni Blandino
- Italian National Cancer Institute, Regina Elena, Translational Oncogenomics Group, Rome 00144, Italy
| | - Mauro Giacca
- International Centre for Genetic Engineering and Biotechnology (ICGEB), Molecular Medicine Laboratory, Trieste 34149, Italy
| | - Silvano Piazza
- Laboratorio Nazionale Consorzio Interuniversitario Biotecnologie (LNCIB), Bioinformatics and Functional Genomics Unit (BFGU), Trieste 34149, Italy
| | - Roberta Benetti
- Laboratorio Nazionale Consorzio Interuniversitario Biotecnologie (LNCIB), Cancer Epigenetics Unit, Trieste 34149, Italy.,Department of Medical and Biological Sciences, Università degli Studi di Udine, Udine 33100, Italy
| | - Stefan Schoeftner
- Laboratorio Nazionale Consorzio Interuniversitario Biotecnologie (LNCIB), Genomic Stability Unit, Trieste 34149, Italy.,Italian National Cancer Institute, Regina Elena, Rome 00144, Italy.,Department of Life Sciences, Università degli Studi di Trieste, Trieste 34127, Italy
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Hapangama DK, Kamal A, Saretzki G. Implications of telomeres and telomerase in endometrial pathology. Hum Reprod Update 2017; 23:166-187. [PMID: 27979878 PMCID: PMC5850744 DOI: 10.1093/humupd/dmw044] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Accepted: 12/02/2016] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Eukaryotic chromosomal ends are linear and are protected by nucleoprotein complexes known as telomeres. The complex structural anatomy and the diverse functions of telomeres as well as the unique reverse transcriptase enzyme, telomerase that maintains telomeres are under intensive scientific scrutiny. Both are involved in many human diseases including cancer, but also in ageing and chronic disease such as diabetes. Their intricate involvement in many cellular processes and pathways is being dynamically deciphered in many organs including the endometrium. This review summarizes our current knowledge on the topic of telomeres and telomerase and their potential role in providing plausible explanations for endometrial aberrations related to common gynaecological pathologies. OBJECTIVE AND RATIONALE This review outlines the recent major findings in telomere and telomerase functions in the context of endometrial biology. It highlights the contemporary discoveries in hormonal regulation, normal endometrial regeneration, stem cells and common gynaecological diseases such as endometriosis, infertility, recurrent reproductive failure and endometrial cancer (EC). SEARCH METHODS The authors carried out systematic PubMed (Medline) and Ovid searches using the key words: telomerase, telomeres, telomere length, human telomerase reverse transcriptase, telomeric RNA component, with endometrium, hormonal regulation, endometrial stem/progenitor cells, endometrial regeneration, endometriosis, recurrent miscarriage, infertility, endometrial hyperplasia, EC and uterine cancer. Publications used in this review date from 1995 until 31st June 2016. OUTCOMES The human endometrium is a unique somatic organ, which displays dynamic telomerase activity (TA) related to the menstrual cycle. Telomerase is implicated in almost all endometrial pathologies and appears to be crucial to endometrial stem cells. In particular, it is vital for normal endometrial regeneration, providing a distinct route to formulate possible curative, non-hormonal therapies to treat chronic endometrial conditions. Furthermore, our current understanding of telomere maintenance in EC is incomplete. Data derived from other malignancies on the role of telomerase in carcinogenesis cannot be extrapolated to EC because unlike in other cancers, TA is already present in proliferating healthy endometrial cells. WIDER IMPLICATIONS Since telomerase is pivotal to endometrial regeneration, further studies elucidating the role of telomeres, telomerase, their associated proteins and their regulation in normal endometrial regeneration as well as their role in endometrial pathologies are essential. This approach may allow future development of novel treatment strategies that are not only non-hormonal but also potentially curative.
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Affiliation(s)
- D K Hapangama
- Department of Women's and Children's Health, Institute of Translational Medicine, University of Liverpool, Liverpool, L8 7SS, UK.,Liverpool Women's Hospital NHS Foundation Trust, Crown Street, Liverpool L8 7SS, UK
| | - A Kamal
- Department of Women's and Children's Health, Institute of Translational Medicine, University of Liverpool, Liverpool, L8 7SS, UK.,The National Center for Early Detection of Cancer, Oncology Teaching Hospital, Baghdad Medical City, Baghdad, Iraq
| | - G Saretzki
- Institute for Ageing and Institute for Cell and Molecular Biosciences, Campus for Ageing and Vitality, Newcastle University, Newcastle upon Tyne, NE4 5PL, UK
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37
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Telomerase reverse transcriptase promotes chemoresistance by suppressing cisplatin-dependent apoptosis in osteosarcoma cells. Sci Rep 2017; 7:7070. [PMID: 28765565 PMCID: PMC5539325 DOI: 10.1038/s41598-017-07204-w] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Accepted: 06/23/2017] [Indexed: 11/18/2022] Open
Abstract
Cisplatin is one of the most efficacious antimitotic drugs used in the treatment of a range of malignant tumors. However, treatment failures are common due to the development of chemoresistance. In addition to its telomere maintenance function, telomerase plays a pro-survival role, inducing decreased apoptosis and increased resistance against DNA damage. Elucidation of the molecular mechanisms underlying this effect is critical to improve treatment outcomes. Previously, our group showed higher telomerase reverse transcriptase(TERT) expression in cisplatin resistant osteosarcoma cells. In this study, confocal fluorescence microscopy experiments revealed that TERT translocates from the nucleus to mitochondria in cisplatin treated osteosarcoma cells. We observed decreased apoptosis rate and improved mitochondrial function in TERT-overexpressing cells following cisplatin treatment. Based on these results, we further established that TERT inhibits cisplatin-induced apoptosis independently of telomerase reverse transcriptase activity. Moreover, TERT suppressed cisplatin-induced apoptosis and improved mitochondrial function via alleviating intracellular ROS in osteosarcoma cells. Our finding that TERT shuttles from the nucleus to the mitochondrion in response to cisplatin treatment and inhibits cisplatin-induced apoptosis in osteosarcoma cells may be especially important to overcome drug resistance.
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38
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G-Quadruplex surveillance in BCL-2 gene: a promising therapeutic intervention in cancer treatment. Drug Discov Today 2017; 22:1165-1186. [PMID: 28506718 DOI: 10.1016/j.drudis.2017.05.001] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Revised: 03/20/2017] [Accepted: 05/05/2017] [Indexed: 02/07/2023]
Abstract
Recently, therapeutic implications of BCL-2 quadruplex invigorated the field of clinical oncology. This Keynote review discusses how a BCL-2 quadruplex-selective approach circumvents the limitations of existing therapeutics; and which improvisations might ameliorate the recent trends of quadruplex-based treatment.
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39
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Li C, Zheng L, Xin Y, Tan Z, Zhang Y, Meng X, Wang Z, Xi T. The competing endogenous RNA network of CYP4Z1 and pseudogene CYP4Z2P exerts an anti-apoptotic function in breast cancer. FEBS Lett 2017; 591:991-1000. [PMID: 28236635 DOI: 10.1002/1873-3468.12608] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Revised: 02/13/2017] [Accepted: 02/20/2017] [Indexed: 12/26/2022]
Abstract
The competing endogenous RNA network (ceRNET) is involved in tumorigenesis and has become a hot spot of research. The ceRNET between CYP4Z1 and the pseudogene CYP4Z2P promotes angiogenesis and mediates tamoxifen resistance in breast cancer. Nevertheless, the effects of this ceRNET on cell apoptosis and related mechanisms remain unclear. In the present study, we found that downregulation of CYP4Z1 or the CYP4Z2P 3'-UTR promotes cell apoptosis, mirroring the functions of human telomerase reverse transcriptase (hTERT). Furthermore, the ceRNET between CYP4Z1 and pseudogene CYP4Z2P modulates hTERT expression by operating as a sub-ceRNET for hTERT. Our data demonstrate that the ceRNET between CYP4Z1 and pseudogene CYP4Z2P acts as a sub-ceRNET for hTERT and, thus, inhibits breast cancer apoptosis.
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Affiliation(s)
- Cheng Li
- School of Life Science and Technology, China Pharmaceutical University, Nanjing, China
- Jiangsu Key Laboratory of Carcinogenesis and Intervention, China Pharmaceutical University, Nanjing, China
| | - Lufeng Zheng
- School of Life Science and Technology, China Pharmaceutical University, Nanjing, China
- Jiangsu Key Laboratory of Carcinogenesis and Intervention, China Pharmaceutical University, Nanjing, China
| | - Yu Xin
- School of Life Science and Technology, China Pharmaceutical University, Nanjing, China
- Jiangsu Key Laboratory of Carcinogenesis and Intervention, China Pharmaceutical University, Nanjing, China
| | - Zhoulin Tan
- School of Life Science and Technology, China Pharmaceutical University, Nanjing, China
- Jiangsu Key Laboratory of Carcinogenesis and Intervention, China Pharmaceutical University, Nanjing, China
| | - Yan Zhang
- School of Life Science and Technology, China Pharmaceutical University, Nanjing, China
- Jiangsu Key Laboratory of Carcinogenesis and Intervention, China Pharmaceutical University, Nanjing, China
| | - Xia Meng
- School of Life Science and Technology, China Pharmaceutical University, Nanjing, China
- Jiangsu Key Laboratory of Carcinogenesis and Intervention, China Pharmaceutical University, Nanjing, China
| | - Zhigang Wang
- College of Pharmacy, China Pharmaceutical University, Nanjing, China
| | - Tao Xi
- School of Life Science and Technology, China Pharmaceutical University, Nanjing, China
- Jiangsu Key Laboratory of Carcinogenesis and Intervention, China Pharmaceutical University, Nanjing, China
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40
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Im E, Yoon JB, Lee HW, Chung KC. Human Telomerase Reverse Transcriptase (hTERT) Positively Regulates 26S Proteasome Activity. J Cell Physiol 2017; 232:2083-2093. [PMID: 27648923 DOI: 10.1002/jcp.25607] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Accepted: 09/19/2016] [Indexed: 02/02/2023]
Abstract
Human telomerase reverse transcriptase (hTERT) is the catalytic subunit of telomerase, an RNA-dependent DNA polymerase that elongates telomeric DNA. hTERT displays several extra-telomeric functions that are independent of its telomere-regulatory function, including tumor progression, and neuronal cell death regulation. In this study, we evaluated these additional hTERT non-telomeric functions. We determined that hTERT interacts with several 19S and 20S proteasome subunits. The 19S regulatory particle and 20S core particle are part of 26S proteasome complex, which plays a central role in ubiquitin-dependent proteolysis. In addition, hTERT positively regulated 26S proteasome activity independent of its enzymatic activity. Moreover, hTERT enhanced subunit interactions, which may underlie hTERT's ability of hTERT to stimulate the 26S proteasome. Furthermore, hTERT displayed cytoprotective effect against ER stress via the activation of 26S proteasome in acute myeloid leukemia cells. Our data suggest that hTERT acts as a novel chaperone to promote 26S proteasome assembly and maintenance. J. Cell. Physiol. 232: 2083-2093, 2017. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Eunju Im
- Department of Systems Biology, College of Life Science and Biotechnology, Yonsei University, Seoul, Korea
| | - Jong Bok Yoon
- Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, Seoul, Korea
| | - Han-Woong Lee
- Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, Seoul, Korea
| | - Kwang Chul Chung
- Department of Systems Biology, College of Life Science and Biotechnology, Yonsei University, Seoul, Korea
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41
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Kang HJ, Cui Y, Yin H, Scheid A, Hendricks WPD, Schmidt J, Sekulic A, Kong D, Trent JM, Gokhale V, Mao H, Hurley LH. A Pharmacological Chaperone Molecule Induces Cancer Cell Death by Restoring Tertiary DNA Structures in Mutant hTERT Promoters. J Am Chem Soc 2016; 138:13673-13692. [PMID: 27643954 DOI: 10.1021/jacs.6b07598] [Citation(s) in RCA: 76] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Activation of human telomerase reverse transcriptase (hTERT) is necessary for limitless replication in tumorigenesis. Whereas hTERT is transcriptionally silenced in normal cells, most tumor cells reactivate hTERT expression by alleviating transcriptional repression through diverse genetic and epigenetic mechanisms. Transcription-activating hTERT promoter mutations have been found to occur at high frequencies in multiple cancer types. These mutations have been shown to form new transcription factor binding sites that drive hTERT expression, but this model cannot fully account for differences in wild-type (WT) and mutant promoter activation and has not yet enabled a selective therapeutic strategy. Here, we demonstrate a novel mechanism by which promoter mutations activate hTERT transcription, which also sheds light on a unique therapeutic opportunity. Promoter mutations occur in a core promoter region that forms tertiary structures consisting of a pair of G-quadruplexes involved in transcriptional silencing. We show that promoter mutations exert a detrimental effect on the folding of one of these G-quadruplexes, resulting in a nonfunctional silencer element that alleviates transcriptional repression. We have also identified a small drug-like pharmacological chaperone (pharmacoperone) molecule, GTC365, that acts at an early step in the G-quadruplex folding pathway to redirect mutant promoter G-quadruplex misfolding, partially reinstate the correct folding pathway, and reduce hTERT activity through transcriptional repression. This transcription-mediated repression produces cancer cell death through multiple routes including both induction of apoptosis through inhibition of hTERT's role in regulating apoptosis-related proteins and induction of senescence by decreasing telomerase activity and telomere length. We demonstrate the selective therapeutic potential of this strategy in melanoma cells that overexpress hTERT.
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Affiliation(s)
- Hyun-Jin Kang
- University of Arizona , College of Pharmacy, 1703 East Mabel Street, Tucson, Arizona 85721, United States
| | - Yunxi Cui
- Department of Chemistry and Biochemistry and School of Biomedical Sciences, Kent State University , Kent, Ohio 44242, United States
| | - Holly Yin
- Translational Genomics Research Institute , 445 North Fifth Street, Phoenix, Arizona 85004, United States
| | - Amy Scheid
- College of Science, University of Arizona , 1040 East Fourth Street, Tucson, Arizona 85721, United States
| | - William P D Hendricks
- Translational Genomics Research Institute , 445 North Fifth Street, Phoenix, Arizona 85004, United States
| | - Jessica Schmidt
- Department of Dermatology, Mayo Clinic , 13400 East Shea Boulevard, Scottsdale, Arizona 85259, United States
| | - Aleksandar Sekulic
- Department of Dermatology, Mayo Clinic , 13400 East Shea Boulevard, Scottsdale, Arizona 85259, United States
| | - Deming Kong
- State Key Laboratory of Medicinal Chemical Biology, College of Chemistry, Nankai University , Tianjin 300071, People's Republic of China
| | - Jeffrey M Trent
- Translational Genomics Research Institute , 445 North Fifth Street, Phoenix, Arizona 85004, United States
| | - Vijay Gokhale
- BIO5 Institute , 1657 East Helen Street, Tucson, Arizona 85721, United States
| | - Hanbin Mao
- Department of Chemistry and Biochemistry and School of Biomedical Sciences, Kent State University , Kent, Ohio 44242, United States
| | - Laurence H Hurley
- University of Arizona , College of Pharmacy, 1703 East Mabel Street, Tucson, Arizona 85721, United States.,BIO5 Institute , 1657 East Helen Street, Tucson, Arizona 85721, United States.,Arizona Cancer Center , 1515 North Campbell Avenue, Tucson, Arizona 85724, United States
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42
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Ropio J, Merlio JP, Soares P, Chevret E. Telomerase Activation in Hematological Malignancies. Genes (Basel) 2016; 7:genes7090061. [PMID: 27618103 PMCID: PMC5039560 DOI: 10.3390/genes7090061] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Revised: 07/15/2016] [Accepted: 07/29/2016] [Indexed: 12/18/2022] Open
Abstract
Telomerase expression and telomere maintenance are critical for cell proliferation and survival, and they play important roles in development and cancer, including hematological malignancies. Transcriptional regulation of the rate-limiting subunit of human telomerase reverse transcriptase gen (hTERT) is a complex process, and unveiling the mechanisms behind its reactivation is an important step for the development of diagnostic and therapeutic applications. Here, we review the main mechanisms of telomerase activation and the associated hematologic malignancies.
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Affiliation(s)
- Joana Ropio
- Cutaneous Lymphoma Oncogenesis Team INSERM U1053 Bordeaux Research in Translational Oncology, Bordeaux University, Bordeaux 33076, France.
- Institute of Biomedical Sciences of Abel Salazar, University of Porto, Porto 4050-313, Portugal.
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto 4200-135, Portugal.
- Institute of Molecular Pathology and Immunology of the University of Porto (Ipatimup)-Cancer Biology, Rua Dr. Roberto Frias, s/n, Porto 4200-465, Portugal.
| | - Jean-Philippe Merlio
- Cutaneous Lymphoma Oncogenesis Team INSERM U1053 Bordeaux Research in Translational Oncology, Bordeaux University, Bordeaux 33076, France.
- Tumor Bank and Tumor Biology Laboratory, University Hospital Center Bordeaux, Pessac 33604, France.
| | - Paula Soares
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto 4200-135, Portugal.
- Institute of Molecular Pathology and Immunology of the University of Porto (Ipatimup)-Cancer Biology, Rua Dr. Roberto Frias, s/n, Porto 4200-465, Portugal.
- Department of Pathology and Oncology, Medical Faculty of Porto University, Porto 4200-319, Portugal.
| | - Edith Chevret
- Cutaneous Lymphoma Oncogenesis Team INSERM U1053 Bordeaux Research in Translational Oncology, Bordeaux University, Bordeaux 33076, France.
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Ci X, Li B, Ma X, Kong F, Zheng C, Björkholm M, Jia J, Xu D. Bortezomib-mediated down-regulation of telomerase and disruption of telomere homeostasis contributes to apoptosis of malignant cells. Oncotarget 2016; 6:38079-92. [PMID: 26472030 PMCID: PMC4741985 DOI: 10.18632/oncotarget.5752] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2015] [Accepted: 09/30/2015] [Indexed: 12/17/2022] Open
Abstract
Bortezomib inhibits the ubiquitin/proteasome pathway to achieve its anti-cancer effect and its well characterized activity is the NF-κB inhibition through which the anti-apoptotic bcl-2 expression is down-regulated and apoptosis is subsequently induced. However, the downstream molecular targets of bortezomib are still incompletely defined. Because telomere stabilization via activation of telomerase, induction of telomerase reverse transcriptase (hTERT) and appropriate expression of shelterin proteins is essential to cancer development and progression, we investigated the effect of bortezomib on telomere homeostasis/function in malignant cells. The bortezomib treatment of leukemic (HEL) and gastric cancer cells (BGC-823) led to significant inhibition of hTERT and telomerase expression, widespread dysregulation of shelterin protein expression, and telomere shortening, thereby triggering telomere dysfunction and DNA damage. hTERT over-expression attenuated bortezomib-induced telomere shortening, abnormal shelterin expression and telomere dysfunction. Importantly, bortezomib-mediated apoptosis of malignant cells was partially prevented by hTERT over-expression. Mechanistically, hTERT first robustly enhances bcl2 expression and maintains significantly high residual levels of bcl2 even in bortezomib-treated HEL cells. Second, hTERT protects against bortezomib-induced DNA damage. Our findings collectively reveal a profound impact of bortezomib on telomere homeostasis/function. Down-regulation of hTERT expression and telomere dysfunction induced by bortezomib both contribute to its cancer cell killing actions. It is evident from the present study that hTERT can confer resistance of malignant cells to bortezomib-based target cancer therapy, which may have important clinical implications.
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Affiliation(s)
- Xinyu Ci
- Central Research Laboratory, Shandong University Second Hospital, Jinan, PR China.,Department of Microbiology, School of Medicine, Shandong University, Jinan, PR China.,Division of Hematology, Department of Medicine and Center for Molecular Medicine, Karolinska Institutet and Karolinska University Hospital Solna, Stockholm, Sweden.,Karolinska Institutet-Shandong University Collaborative Laboratories for Cancer and Stem Cell Research, Jinan, PR China
| | - Bingnan Li
- Division of Hematology, Department of Medicine and Center for Molecular Medicine, Karolinska Institutet and Karolinska University Hospital Solna, Stockholm, Sweden
| | - Xueping Ma
- Central Research Laboratory, Shandong University Second Hospital, Jinan, PR China.,Department of Microbiology, School of Medicine, Shandong University, Jinan, PR China.,Karolinska Institutet-Shandong University Collaborative Laboratories for Cancer and Stem Cell Research, Jinan, PR China
| | - Feng Kong
- Central Research Laboratory, Shandong University Second Hospital, Jinan, PR China.,Karolinska Institutet-Shandong University Collaborative Laboratories for Cancer and Stem Cell Research, Jinan, PR China
| | - Chengyun Zheng
- Karolinska Institutet-Shandong University Collaborative Laboratories for Cancer and Stem Cell Research, Jinan, PR China.,Department of Hematology, Shandong University Second Hospital, Jinan, PR China
| | - Magnus Björkholm
- Division of Hematology, Department of Medicine and Center for Molecular Medicine, Karolinska Institutet and Karolinska University Hospital Solna, Stockholm, Sweden.,Karolinska Institutet-Shandong University Collaborative Laboratories for Cancer and Stem Cell Research, Jinan, PR China
| | - Jihui Jia
- Department of Microbiology, School of Medicine, Shandong University, Jinan, PR China.,Karolinska Institutet-Shandong University Collaborative Laboratories for Cancer and Stem Cell Research, Jinan, PR China
| | - Dawei Xu
- Division of Hematology, Department of Medicine and Center for Molecular Medicine, Karolinska Institutet and Karolinska University Hospital Solna, Stockholm, Sweden.,Karolinska Institutet-Shandong University Collaborative Laboratories for Cancer and Stem Cell Research, Jinan, PR China
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Zhang X, Li B, de Jonge N, Björkholm M, Xu D. The DNA methylation inhibitor induces telomere dysfunction and apoptosis of leukemia cells that is attenuated by telomerase over-expression. Oncotarget 2016; 6:4888-900. [PMID: 25682873 PMCID: PMC4467122 DOI: 10.18632/oncotarget.2917] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2014] [Accepted: 12/14/2014] [Indexed: 01/27/2023] Open
Abstract
DNA methyltransferase inhibitors (DNMTIs) such as 5-azacytidine (5-AZA) have been used for treatment of acute myeloid leukemia (AML) and other malignancies. Although inhibiting global/gene-specific DNA methylation is widely accepted as a key mechanism behind DNMTI anti-tumor activity, other mechanisms are likely involved in DNMTI's action. Because telomerase reverse transcriptase (TERT) plays key roles in cancer through telomere elongation and telomere lengthening-independent activities, and TERT has been shown to confer chemo- or radio-resistance to cancer cells, we determine whether DNMTIs affect telomere function and whether TERT/telomerase interferes with their anti-cancer efficacy. We showed that 5-AZA induced DNA damage and telomere dysfunction in AML cell lines by demonstrating the presence of 53-BP1 foci and the co-localization of 53-BP1 foci with telomere signals, respectively. Telomere dysfunction was coupled with diminished TERT expression, shorter telomere and apoptosis in 5-AZA-treated cells. However, 5-AZA treatment did not lead to changes in the methylation status of subtelomere regions. Down-regulation of TERT expression similarly occurred in primary leukemic cells derived from AML patients exposed to 5-AZA. TERT over-expression significantly attenuated 5-AZA-mediated DNA damage, telomere dysfunction and apoptosis of AML cells. Collectively, 5-AZA mediates the down-regulation of TERT expression, and induces telomere dysfunction, which consequently exerts an anti-tumor activity.
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Affiliation(s)
- Xiaolu Zhang
- Department of Medicine, Division of Hematology and Center for Molecular Medicine, Karolinska Institutet and Karolinska University Hospital Solna, Stockholm, Sweden
| | - Bingnan Li
- Department of Medicine, Division of Hematology and Center for Molecular Medicine, Karolinska Institutet and Karolinska University Hospital Solna, Stockholm, Sweden
| | - Nick de Jonge
- Department of Medicine, Division of Hematology and Center for Molecular Medicine, Karolinska Institutet and Karolinska University Hospital Solna, Stockholm, Sweden
| | - Magnus Björkholm
- Department of Medicine, Division of Hematology and Center for Molecular Medicine, Karolinska Institutet and Karolinska University Hospital Solna, Stockholm, Sweden
| | - Dawei Xu
- Department of Medicine, Division of Hematology and Center for Molecular Medicine, Karolinska Institutet and Karolinska University Hospital Solna, Stockholm, Sweden
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New surprises from an old favourite: The emergence of telomerase as a key player in the regulation of cancer stemness. Biochimie 2016; 121:170-8. [DOI: 10.1016/j.biochi.2015.12.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2015] [Accepted: 12/09/2015] [Indexed: 12/30/2022]
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46
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Lee JS, Jeong SW, Cho SW, Juhn JP, Kim KW. Relationship between Initial Telomere Length, Initial Telomerase Activity, Age, and Replicative Capacity of Nucleus Pulposus Chondrocytes in Human Intervertebral Discs: What Is a Predictor of Replicative Potential? PLoS One 2015; 10:e0144177. [PMID: 26633809 PMCID: PMC4669191 DOI: 10.1371/journal.pone.0144177] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Accepted: 11/13/2015] [Indexed: 02/06/2023] Open
Abstract
There is evidence that telomere length (TL), telomerase activity (TA), and age are related to the replicative potential of human nucleus pulposus chondrocytes (NPCs). However, it has not yet been established if any of these factors can serve as predictors of the replicative potential of NPCs. To establish predictors of the replicative potential of NPCs, we evaluated potential relationships between replicative capacity of NPCs, initial TL (telomere length at the first passage), initial TA (telomerase activity at the first passage), and age. Nucleus pulposus specimens were obtained from 14 patients of various ages undergoing discectomy. NPCs were serially cultivated until the end of their replicative lifespans. Relationships among cumulative population doubling level (PDL), initial TL, initial TA, and age were analyzed. Initial TA was negatively correlated with age (r = -0.674, P = 0.008). However, no correlation between initial TL and age was observed. Cumulative PDL was also negatively correlated with age (r = -0.585, P = 0.028). Although the cumulative PDL appeared to increase with initial TL or initial TA, this trend was not statistically significant. In conclusion, age is the sole predictor of the replicative potential of human NPCs, and replicative potential decreases with age. Initial TL and initial TA are not predictors of replicative potential, and can serve only as reference values.
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Affiliation(s)
- Jun-Seok Lee
- Department of Orthopedic Surgery, Yeouido St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea
- Department of Orthopedic Research, Medical Research Institute, Yeouido St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea
- * E-mail:
| | - Seo-Won Jeong
- Department of Orthopedic Research, Medical Research Institute, Yeouido St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Sung-Wook Cho
- Department of Orthopedic Surgery, Yeouido St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Joon-Pyo Juhn
- Department of Orthopedic Surgery, Yeouido St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Ki-Won Kim
- Department of Orthopedic Surgery, Yeouido St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea
- Department of Orthopedic Research, Medical Research Institute, Yeouido St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea
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Babizhayev MA, Yegorov YE. Tissue formation and tissue engineering through host cell recruitment or a potential injectable cell-based biocomposite with replicative potential: Molecular mechanisms controlling cellular senescence and the involvement of controlled transient telomerase activation therapies. J Biomed Mater Res A 2015; 103:3993-4023. [PMID: 26034007 DOI: 10.1002/jbm.a.35515] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2015] [Accepted: 05/18/2015] [Indexed: 01/04/2023]
Abstract
Accumulated data indicate that wound-care products should have a composition equivalent to that of the skin: a combination of particular growth factors and extracellular matrix (ECM) proteins endogenous to the skin, together with viable epithelial cells, fibroblasts, and mesenchymal stem cells (MSCs). Strategies consisting of bioengineered dressings and cell-based products have emerged for widespread clinical use; however, their performance is not optimal because chronic wounds persist as a serious unmet medical need. Telomerase, the ribonucleoprotein complex that adds telomeric repeats to the ends of chromosomes, is responsible for telomere maintenance, and its expression is associated with cell immortalization and, in certain cases, cancerogenesis. Telomerase contains a catalytic subunit, the telomerase reverse transcriptase (hTERT). Introduction of TERT into human cells extends both their lifespan and their telomeres to lengths typical of young cells. The regulation of TERT involves transcriptional and posttranscriptional molecular biology mechanisms. The manipulation, regulation of telomerase is multifactorial in mammalian cells, involving overall telomerase gene expression, post-translational protein-protein interactions, and protein phosphorylation. Reactive oxygen species (ROS) have been implicated in aging, apoptosis, and necrosis of cells in numerous diseases. Upon production of high levels of ROS from exogenous or endogenous generators, the redox balance is perturbed and cells are shifted into a state of oxidative stress, which subsequently leads to modifications of intracellular proteins and membrane lipid peroxidation and to direct DNA damage. When the oxidative stress is severe, survival of the cell is dependent on the repair or replacement of damaged molecules, which can result in induction of apoptosis in the injured with ROS cells. ROS-mediated oxidative stress induces the depletion of hTERT from the nucleus via export through the nuclear pores. Nuclear export is initiated by ROS-induced phosphorylation of tyrosine 707 within hTERT by the Src kinase family. It might be presumed that protection of mitochondria against oxidative stress is an important telomere length-independent function for telomerase in cell survival. Biotechnology companies are focused on development of therapeutic telomerase vaccines, telomerase inhibitors, and telomerase promoter-driven cell killing in oncology, have a telomerase antagonist in late preclinical studies. Anti-aging medicine-oriented groups have intervened on the market with products working on telomerase activation for a broad range of degenerative diseases in which replicative senescence or telomere dysfunction may play an important role. Since oxidative damage has been shown to shorten telomeres in tissue culture models, the adequate topical, transdermal, or systemic administration of antioxidants (such as, patented ocular administration of 1% N-acetylcarnosine lubricant eye drops in the treatment of cataracts) may be beneficial at preserving telomere lengths and delaying the onset or in treatment of disease in susceptible individuals. Therapeutic strategies toward controlled transient activation of telomerase are targeted to cells and replicative potential in cell-based therapies, tissue engineering and regenerative medicine.
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Affiliation(s)
- Mark A Babizhayev
- Innovative Vision Products, Inc., 3511 Silverside Road, Suite 105, County of New Castle, Delaware, 19810
| | - Yegor E Yegorov
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 32 Vavilov Street, Moscow, 119991, Russian Federation
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Gandolfi G, Ragazzi M, Frasoldati A, Piana S, Ciarrocchi A, Sancisi V. TERT promoter mutations are associated with distant metastases in papillary thyroid carcinoma. Eur J Endocrinol 2015; 172:403-13. [PMID: 25583906 DOI: 10.1530/eje-14-0837] [Citation(s) in RCA: 90] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
OBJECTIVE Transcriptional activating mutations in the promoter of the telomerase reverse transcriptase (TERT) gene were reported at high frequency in aggressive poorly differentiated and anaplastic thyroid cancers. By contrast, the relevance of these mutations in the metastatic behavior of well-differentiated thyroid cancer is still to be defined. The aim of this work was to investigate the frequency of TERT promoter mutations in a remarkable cohort of well-differentiated papillary thyroid carcinoma that developed distant metastases (DM-PTCs) and to establish whether these mutations may be predictive of metastatic behavior. DESIGN We analyzed the frequency of TERT promoter mutations in a group of 43 highly aggressive DM-PTCs. As controls, we analyzed these mutations in a group of 78 PTCs without distant metastases (control-PTCs). The possible correlation between TERT promoter mutations and BRAF V600E mutation was also investigated. METHODS TERT promoter mutational status was evaluated by direct sequencing of the hotspot harboring the C228T and the C250T mutations. RESULTS In the overall cohort of 121 PTCs analyzed, 17% of cases (21/121) carried a mutation in the TERT promoter. Noticeably, 33% of DM-PTCs were mutated in the TERT promoter while only 9% of the control-PTCs showed a mutation in this locus. We also observed a positive association between BRAF V600E and TERT C228T mutations in the cohort of DM-PTCs. CONCLUSIONS These results indicate that TERT promoter mutations are associated with the development of distant metastases in PTCs and may help in predicting aggressive behavior in this type of tumor.
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Affiliation(s)
- Greta Gandolfi
- Laboratory of Translational ResearchPathology UnitEndocrinology UnitArcispedale S. Maria Nuova-IRCCS, Viale Risorgimento 80, 42123 Reggio Emilia, Italy
| | - Moira Ragazzi
- Laboratory of Translational ResearchPathology UnitEndocrinology UnitArcispedale S. Maria Nuova-IRCCS, Viale Risorgimento 80, 42123 Reggio Emilia, Italy
| | - Andrea Frasoldati
- Laboratory of Translational ResearchPathology UnitEndocrinology UnitArcispedale S. Maria Nuova-IRCCS, Viale Risorgimento 80, 42123 Reggio Emilia, Italy
| | - Simonetta Piana
- Laboratory of Translational ResearchPathology UnitEndocrinology UnitArcispedale S. Maria Nuova-IRCCS, Viale Risorgimento 80, 42123 Reggio Emilia, Italy
| | - Alessia Ciarrocchi
- Laboratory of Translational ResearchPathology UnitEndocrinology UnitArcispedale S. Maria Nuova-IRCCS, Viale Risorgimento 80, 42123 Reggio Emilia, Italy
| | - Valentina Sancisi
- Laboratory of Translational ResearchPathology UnitEndocrinology UnitArcispedale S. Maria Nuova-IRCCS, Viale Risorgimento 80, 42123 Reggio Emilia, Italy
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Qin Y, Guo H, Tang B, Yang SM. The non-reverse transcriptase activity of the human telomerase reverse transcriptase promotes tumor progression (review). Int J Oncol 2014; 45:525-31. [PMID: 24888567 DOI: 10.3892/ijo.2014.2470] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Accepted: 04/17/2014] [Indexed: 11/05/2022] Open
Abstract
In human cancer, high expression of telomerase is correlated with tumor aggressiveness and metastatic potential. Human telomerase reverse transcriptase (hTERT), which regulates telomere length, can promote tumor development. Most research on hTERT has been focused on its crucial function of telomere maintenance. However, there are many phenomena that cannot be explained by its reverse transcriptase activity. Accumulating evidence suggests that hTERT has functions independent of its protective function at the telomere ends, such as increasing the anti-apoptotic capacity of cells, enhancing DNA repair, maintaining stem cells and regulating gene expression. This review will provide an update on the non-reverse transcriptase activity of hTERT and its contribution to tumor formation, metastasis and cancer stem cell maintenance. Repression of the non-reverse transcriptase activity of hTERT may be a new strategy for tumor therapy.
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Affiliation(s)
- Yong Qin
- Department of Gastroenterology, Xinqiao Hospital, Third Military Medical University, Chongqing 400037, P.R. China
| | - Hong Guo
- Department of Gastroenterology, Xinqiao Hospital, Third Military Medical University, Chongqing 400037, P.R. China
| | - Bo Tang
- Department of Gastroenterology, Xinqiao Hospital, Third Military Medical University, Chongqing 400037, P.R. China
| | - Shi-Ming Yang
- Department of Gastroenterology, Xinqiao Hospital, Third Military Medical University, Chongqing 400037, P.R. China
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Dolcetti R, Giunco S, Dal Col J, Celeghin A, Mastorci K, De Rossi A. Epstein-Barr virus and telomerase: from cell immortalization to therapy. Infect Agent Cancer 2014; 9:8. [PMID: 24572088 PMCID: PMC3943417 DOI: 10.1186/1750-9378-9-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Accepted: 02/24/2014] [Indexed: 12/18/2022] Open
Abstract
Overcoming cellular senescence is strictly required for virus-driven tumors, including those associated with Epstein-Barr virus (EBV). This critical step is successfully accomplished by EBV through TERT expression and telomerase activation in infected cells. We herein review the complex interplay between EBV and TERT/telomerase in EBV-driven tumorigenesis. Evidence accumulated so far clearly indicates that elucidation of this issue may offer promising opportunities for the design of innovative treatment modalities for EBV-associated malignancies. Indeed, several therapeutic strategies for telomerase inhibition have been developed and are being investigated in clinical trials. In this respect, our recent finding that TERT inhibition sensitizes EBV+ lymphoma cells to antivirals through activation of EBV lytic replication is particularly promising and provides a rationale for the activation of clinical studies aimed at assessing the effects of combination therapies with TERT inhibitors and antivirals for the treatment of EBV-associated malignancies.
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Affiliation(s)
- Riccardo Dolcetti
- Cancer Bio-Immunotherapy Unit, CRO Aviano, National Cancer Institute, Aviano, PN, Italy.
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