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Kageler L, Aquilanti E. Discovery of telomerase inhibitors: existing strategies and emerging innovations. Biochem Soc Trans 2024; 52:1957-1968. [PMID: 39194999 DOI: 10.1042/bst20230264] [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: 02/08/2024] [Revised: 08/05/2024] [Accepted: 08/06/2024] [Indexed: 08/29/2024]
Abstract
Telomerase, crucial for maintaining telomere length, is an attractive target for cancer therapy due to its role in cellular immortality. Despite three decades of research efforts, no small-molecule telomerase inhibitors have been clinically approved, highlighting the extensive challenges in developing effective telomerase-based therapeutics. This review examines conventional and emerging methods to measure telomerase activity and discusses existing inhibitors, including oligonucleotides and small molecules. Furthermore, this review highlights recent breakthroughs in structural studies of telomerase using cryo-electron microscopy, which can facilitate improved structure-based drug design. Altogether, advancements in structural methodologies and high-throughput screening offer promising prospects for telomerase-based cancer therapeutic development.
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Affiliation(s)
- Lauren Kageler
- Stem Cell Program and Division of Hematology/Oncology, Boston Children's Hospital, Boston, MA, U.S.A
| | - Elisa Aquilanti
- Division of Neuro Oncology, Dana Farber Cancer Institute, Boston, MA, U.S.A
- Department of Medical Oncology, Dana Farber Cancer Institute, Boston, MA, U.S.A
- Cancer Program, Broad Institute of MIT and Harvard, Cambridge, MA, U.S.A
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González‐Sales M, Lennox AL, Huang F, Pamulapati C, Wan Y, Sun L, Berry T, Kelly Behrs M, Feller F, Morcos PN. Population pharmacokinetics of imetelstat, a first-in-class oligonucleotide telomerase inhibitor. CPT Pharmacometrics Syst Pharmacol 2024; 13:1264-1277. [PMID: 38771074 PMCID: PMC11247122 DOI: 10.1002/psp4.13160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Revised: 04/30/2024] [Accepted: 05/07/2024] [Indexed: 05/22/2024] Open
Abstract
Imetelstat is a novel, first-in-class, oligonucleotide telomerase inhibitor in development for the treatment of hematologic malignancies including lower-risk myelodysplastic syndromes and myelofibrosis. A nonlinear mixed-effects model was developed to characterize the population pharmacokinetics of imetelstat and identify and quantify covariates that contribute to its pharmacokinetic variability. The model was developed using plasma concentrations from 7 clinical studies including 424 patients with solid tumors or hematologic malignancies who received single-agent imetelstat via intravenous infusion at various dose levels (0.4-11.7 mg/kg) and schedules (every week to every 4 weeks). Covariate analysis included factors related to demographics, disease, laboratory results, renal and hepatic function, and antidrug antibodies. Imetelstat was described by a two-compartment, nonlinear disposition model with saturable binding/distribution and dose- and time-dependent elimination from the central compartment. Theory-based allometric scaling for body weight was included in disposition parameters. The final covariates included sex, time, malignancy, and dose on clearance; malignancy and sex on volume of the central compartment; and malignancy and spleen volume on concentration of target. Clearance in females was modestly lower, resulting in nonclinically relevant increases in predicted exposure relative to males. No effects on imetelstat pharmacokinetics were identified for mild-to-moderate hepatic or renal impairment, age, race, and antidrug antibody status. All model parameters were estimated with adequate precision (relative standard error < 29%). Visual predictive checks confirmed the capacity of the model to describe the data. The analysis supports the imetelstat body-weight-based dosing approach and lack of need for dose individualizations for imetelstat-treated patients.
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Affiliation(s)
- Mario González‐Sales
- Modeling Great Solutions Pharmaceutical Research & StudiesFZEDubaiUnited Arab Emirates
| | - Ashley L. Lennox
- Geron CorporationParsippanyNew JerseyUSA
- AllucentCaryNorth CarolinaUSA
| | - Fei Huang
- Geron CorporationParsippanyNew JerseyUSA
| | | | - Ying Wan
- Geron CorporationParsippanyNew JerseyUSA
| | - Libo Sun
- Geron CorporationParsippanyNew JerseyUSA
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3
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Gu L, Liu M, Zhang Y, Zhou H, Wang Y, Xu ZX. Telomere-related DNA damage response pathways in cancer therapy: prospective targets. Front Pharmacol 2024; 15:1379166. [PMID: 38910895 PMCID: PMC11190371 DOI: 10.3389/fphar.2024.1379166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Accepted: 05/23/2024] [Indexed: 06/25/2024] Open
Abstract
Maintaining the structural integrity of genomic chromosomal DNA is an essential role of cellular life and requires two important biological mechanisms: the DNA damage response (DDR) mechanism and telomere protection mechanism at chromosome ends. Because abnormalities in telomeres and cellular DDR regulation are strongly associated with human aging and cancer, there is a reciprocal regulation of telomeres and cellular DDR. Moreover, several drug treatments for DDR are currently available. This paper reviews the progress in research on the interaction between telomeres and cellular DNA damage repair pathways. The research on the crosstalk between telomere damage and DDR is important for improving the efficacy of tumor treatment. However, further studies are required to confirm this hypothesis.
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Affiliation(s)
- Liting Gu
- Key Laboratory of Pathobiology, Ministry of Education, Jilin University, Changchun, Jilin, China
| | - Mingdi Liu
- Key Laboratory of Pathobiology, Ministry of Education, Jilin University, Changchun, Jilin, China
| | - Yuning Zhang
- Key Laboratory of Pathobiology, Ministry of Education, Jilin University, Changchun, Jilin, China
| | - Honglan Zhou
- Department of Urology, The First Hospital of Jilin University, Changchun, Jilin, China
| | - Yishu Wang
- Key Laboratory of Pathobiology, Ministry of Education, Jilin University, Changchun, Jilin, China
| | - Zhi-Xiang Xu
- Key Laboratory of Pathobiology, Ministry of Education, Jilin University, Changchun, Jilin, China
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Yan S, Lin S, Qiu H, Wang X, He Y, Wang C, Huang Y. Regulation of telomerase towards tumor therapy. Cell Biosci 2023; 13:228. [PMID: 38111043 PMCID: PMC10726632 DOI: 10.1186/s13578-023-01181-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Accepted: 12/02/2023] [Indexed: 12/20/2023] Open
Abstract
Cancer is an aging-related disease, while aging plays an important role in the development process of tumor, thus the two are inextricably associated. Telomere attrition is one of the recognized hallmark events of senescence. Hence, targeting telomerase which could extends telomere sequences to treat tumors is widely favored. Cancer cells rely on high activity of telomerase to maintain a strong proliferative potential. By inhibiting the expression or protein function of telomerase, the growth of cancer cells can be significantly suppressed. In addition, the human immune system itself has a defense system against malignant tumors. However, excessive cell division results in dramatic shortening on telomeres and decline in the function of immune organs that facilitates cancer cell evasion. It has been shown that increasing telomerase activity or telomere length of these immune cells can attenuate senescence, improve cellular viability, and enhance the immunosuppressive microenvironment of tumor. In this paper, we review the telomerase-targeting progress using different anti-tumor strategies from the perspectives of cancer cells and immune cells, respectively, as well as tracking the preclinical and clinical studies of some representative drugs for the prevention or treatment of tumors.
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Affiliation(s)
- Siyu Yan
- MOE Key Laboratory of Gene Function and Regulation and Guangzhou Key Laboratory of Healthy Aging, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510275, China
- Lumiere Therapeutics Co., Ltd., Suzhou, 215000, China
| | - Song Lin
- MOE Key Laboratory of Gene Function and Regulation and Guangzhou Key Laboratory of Healthy Aging, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510275, China
| | - Hongxin Qiu
- MOE Key Laboratory of Gene Function and Regulation and Guangzhou Key Laboratory of Healthy Aging, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510275, China
| | - Xining Wang
- MOE Key Laboratory of Gene Function and Regulation and Guangzhou Key Laboratory of Healthy Aging, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510275, China
| | - Yijun He
- MOE Key Laboratory of Gene Function and Regulation and Guangzhou Key Laboratory of Healthy Aging, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510275, China
| | - Chuanle Wang
- MOE Key Laboratory of Gene Function and Regulation and Guangzhou Key Laboratory of Healthy Aging, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510275, China
- Department of Oncology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, 510275, China
| | - Yan Huang
- MOE Key Laboratory of Gene Function and Regulation and Guangzhou Key Laboratory of Healthy Aging, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510275, China.
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Olschok K, Altenburg B, de Toledo MAS, Maurer A, Abels A, Beier F, Gezer D, Isfort S, Paeschke K, Brümmendorf TH, Zenke M, Chatain N, Koschmieder S. The telomerase inhibitor imetelstat differentially targets JAK2V617F versus CALR mutant myeloproliferative neoplasm cells and inhibits JAK-STAT signaling. Front Oncol 2023; 13:1277453. [PMID: 37941547 PMCID: PMC10628476 DOI: 10.3389/fonc.2023.1277453] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Accepted: 10/09/2023] [Indexed: 11/10/2023] Open
Abstract
Imetelstat shows activity in patients with myeloproliferative neoplasms, including primary myelofibrosis (PMF) and essential thrombocythemia. Here, we describe a case of prolonged disease stabilization by imetelstat treatment of a high-risk PMF patient enrolled into the clinical study MYF2001. We confirmed continuous shortening of telomere length (TL) by imetelstat treatment but observed emergence and expansion of a KRAST58I mutated clone during the patient's clinical course. In order to investigate the molecular mechanisms involved in the imetelstat treatment response, we generated induced pluripotent stem cells (iPSC) from this patient. TL of iPSC-derived hematopoietic stem and progenitor cells, which was increased after reprogramming, was reduced upon imetelstat treatment for 14 days. However, while imetelstat reduced clonogenic growth of the patient's primary CD34+ cells, clonogenic growth of iPSC-derived CD34+ cells was not affected, suggesting that TL was not critically short in these cells. Also, the propensity of iPSC differentiation toward megakaryocytes and granulocytes was not altered. Using human TF-1MPL and murine 32DMPL cell lines stably expressing JAK2V617F or CALRdel52, imetelstat-induced reduction of viability was significantly more pronounced in CALRdel52 than in JAK2V617F cells. This was associated with an immediate downregulation of JAK2 phosphorylation and downstream signaling as well as a reduction of hTERT and STAT3 mRNA expression. Hence, our data demonstrate that imetelstat reduces TL and targets JAK/STAT signaling, particularly in CALR-mutated cells. Although the exact patient subpopulation who will benefit most from imetelstat needs to be defined, our data propose that CALR-mutated clones are highly vulnerable.
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Affiliation(s)
- Kathrin Olschok
- Department of Hematology, Oncology, Hemostaseology, and Stem Cell Transplantation, Faculty of Medicine, RWTH Aachen University, Aachen, Germany
- Center for Integrated Oncology Aachen Bonn Cologne Düsseldorf (CIO ABCD), Aachen, Germany
| | - Bianca Altenburg
- Department of Hematology, Oncology, Hemostaseology, and Stem Cell Transplantation, Faculty of Medicine, RWTH Aachen University, Aachen, Germany
- Center for Integrated Oncology Aachen Bonn Cologne Düsseldorf (CIO ABCD), Aachen, Germany
| | - Marcelo A. S. de Toledo
- Department of Hematology, Oncology, Hemostaseology, and Stem Cell Transplantation, Faculty of Medicine, RWTH Aachen University, Aachen, Germany
- Center for Integrated Oncology Aachen Bonn Cologne Düsseldorf (CIO ABCD), Aachen, Germany
| | - Angela Maurer
- Department of Hematology, Oncology, Hemostaseology, and Stem Cell Transplantation, Faculty of Medicine, RWTH Aachen University, Aachen, Germany
- Center for Integrated Oncology Aachen Bonn Cologne Düsseldorf (CIO ABCD), Aachen, Germany
| | - Anne Abels
- Department of Hematology, Oncology, Hemostaseology, and Stem Cell Transplantation, Faculty of Medicine, RWTH Aachen University, Aachen, Germany
- Center for Integrated Oncology Aachen Bonn Cologne Düsseldorf (CIO ABCD), Aachen, Germany
| | - Fabian Beier
- Department of Hematology, Oncology, Hemostaseology, and Stem Cell Transplantation, Faculty of Medicine, RWTH Aachen University, Aachen, Germany
- Center for Integrated Oncology Aachen Bonn Cologne Düsseldorf (CIO ABCD), Aachen, Germany
| | - Deniz Gezer
- Department of Hematology, Oncology, Hemostaseology, and Stem Cell Transplantation, Faculty of Medicine, RWTH Aachen University, Aachen, Germany
- Center for Integrated Oncology Aachen Bonn Cologne Düsseldorf (CIO ABCD), Aachen, Germany
| | - Susanne Isfort
- Department of Hematology, Oncology, Hemostaseology, and Stem Cell Transplantation, Faculty of Medicine, RWTH Aachen University, Aachen, Germany
- Center for Integrated Oncology Aachen Bonn Cologne Düsseldorf (CIO ABCD), Aachen, Germany
| | - Katrin Paeschke
- Center for Integrated Oncology Aachen Bonn Cologne Düsseldorf (CIO ABCD), Aachen, Germany
- Institute of Clinical Chemistry and Clinical Pharmacology, University Hospital Bonn, Bonn, Germany
| | - Tim H. Brümmendorf
- Department of Hematology, Oncology, Hemostaseology, and Stem Cell Transplantation, Faculty of Medicine, RWTH Aachen University, Aachen, Germany
- Center for Integrated Oncology Aachen Bonn Cologne Düsseldorf (CIO ABCD), Aachen, Germany
| | - Martin Zenke
- Department of Hematology, Oncology, Hemostaseology, and Stem Cell Transplantation, Faculty of Medicine, RWTH Aachen University, Aachen, Germany
- Center for Integrated Oncology Aachen Bonn Cologne Düsseldorf (CIO ABCD), Aachen, Germany
| | - Nicolas Chatain
- Department of Hematology, Oncology, Hemostaseology, and Stem Cell Transplantation, Faculty of Medicine, RWTH Aachen University, Aachen, Germany
- Center for Integrated Oncology Aachen Bonn Cologne Düsseldorf (CIO ABCD), Aachen, Germany
| | - Steffen Koschmieder
- Department of Hematology, Oncology, Hemostaseology, and Stem Cell Transplantation, Faculty of Medicine, RWTH Aachen University, Aachen, Germany
- Center for Integrated Oncology Aachen Bonn Cologne Düsseldorf (CIO ABCD), Aachen, Germany
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Martínez-Montero S, Rajwanshi VK, Pandey RK, De Costa NTS, Hong J, Beigelman L, Gryaznov SM, Pourshahian S. New Oligonucleotide 2'-O-Alkyl N3'→P5' (Thio)-Phosphoramidates as Potent Antisense Agents: Physicochemical Properties and Biological Activity. Nucleic Acid Ther 2023; 33:319-328. [PMID: 37638793 DOI: 10.1089/nat.2023.0014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/29/2023] Open
Abstract
We describe here the design, synthesis, physicochemical properties, and hepatitis B antiviral activity of new 2'-O-alkyl ribonucleotide N3'→P5' phosphoramidate (2'-O-alkyl-NPO) and (thio)-phosphoramidite (2'-O-alkyl-NPS) oligonucleotide analogs. Oligonucleotides with different 2'-O-alkyl modifications such as 2'-O-methyl, -O-ethyl, -O-allyl, and -O-methoxyethyl combined with 3'-amino sugar-phosphate backbone were synthesized and evaluated. These molecules form stable duplexes with complementary DNA and RNA strands. They show an increase in duplex melting temperatures of up to 2.5°C and 4°C per linkage, respectively, compared to unmodified DNA. The results agree with predominantly C3'-endo sugar pucker conformation. Moreover, 2'-O-alkyl phosphoramidites demonstrate higher hydrolytic stability at pH 5.5 than 2'-deoxy NPOs. In addition, the relative lipophilicity of the 2'-O-alkyl-NPO and NPS oligonucleotides is higher than that of their 3'-O- counterparts. The 2'-O-alkyl-NPS oligonucleotides were evaluated as antisense (ASO) compounds in vitro and in vivo using Hepatitis B virus as a model system. Subcutaneous delivery of GalNAc conjugated 2'-O-MOE-NPS gapmers demonstrated higher activity than the 3'-O-containing 2'-O-MOE counterpart. The properties of 2'-O-alkyl-NPS constructs make them attractive candidates as ASO suitable for further evaluation and development.
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Affiliation(s)
- Saúl Martínez-Montero
- Janssen Pharmaceutical Companies of Johnson and Johnson, South San Francisco, California, USA
| | - Vivek K Rajwanshi
- Janssen Pharmaceutical Companies of Johnson and Johnson, South San Francisco, California, USA
| | - Rajendra K Pandey
- Janssen Pharmaceutical Companies of Johnson and Johnson, South San Francisco, California, USA
| | - N Tilani S De Costa
- Janssen Pharmaceutical Companies of Johnson and Johnson, South San Francisco, California, USA
| | - Jin Hong
- Janssen Pharmaceutical Companies of Johnson and Johnson, South San Francisco, California, USA
| | - Leonid Beigelman
- Janssen Pharmaceutical Companies of Johnson and Johnson, South San Francisco, California, USA
| | - Sergei M Gryaznov
- Janssen Pharmaceutical Companies of Johnson and Johnson, South San Francisco, California, USA
| | - Soheil Pourshahian
- Janssen Pharmaceutical Companies of Johnson and Johnson, South San Francisco, California, USA
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7
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Tornesello ML, Tornesello AL, Starita N, Cerasuolo A, Izzo F, Buonaguro L, Buonaguro FM. Telomerase: a good target in hepatocellular carcinoma? An overview of relevant preclinical data. Expert Opin Ther Targets 2022; 26:767-780. [PMID: 36369706 DOI: 10.1080/14728222.2022.2147062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- Maria Lina Tornesello
- Molecular Biology and Viral Oncology Unit, Istituto Nazionale Tumori IRCCS “Fondazione G. Pascale”, 80131 Napoli, Italy
| | - Anna Lucia Tornesello
- Molecular Biology and Viral Oncology Unit, Istituto Nazionale Tumori IRCCS “Fondazione G. Pascale”, 80131 Napoli, Italy
| | - Noemy Starita
- Molecular Biology and Viral Oncology Unit, Istituto Nazionale Tumori IRCCS “Fondazione G. Pascale”, 80131 Napoli, Italy
| | - Andrea Cerasuolo
- Molecular Biology and Viral Oncology Unit, Istituto Nazionale Tumori IRCCS “Fondazione G. Pascale”, 80131 Napoli, Italy
| | - Francesco Izzo
- Hepatobiliary Surgical Oncology Unit, Istituto Nazionale Tumori IRCCS Fondazione Pascale-IRCCS di Napoli, 80131 Naples, Italy
| | - Luigi Buonaguro
- Laboratory of Cancer Immunoregulation, Istituto Nazionale Tumori IRCCS “Fondazione G. Pascale”, 80131 Napoli, Italy
| | - Franco Maria Buonaguro
- Molecular Biology and Viral Oncology Unit, Istituto Nazionale Tumori IRCCS “Fondazione G. Pascale”, 80131 Napoli, Italy
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Piskorz WM, Cechowska-Pasko M. Senescence of Tumor Cells in Anticancer Therapy—Beneficial and Detrimental Effects. Int J Mol Sci 2022; 23:ijms231911082. [PMID: 36232388 PMCID: PMC9570404 DOI: 10.3390/ijms231911082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 09/16/2022] [Accepted: 09/18/2022] [Indexed: 01/10/2023] Open
Abstract
Cellular senescence process results in stable cell cycle arrest, which prevents cell proliferation. It can be induced by a variety of stimuli including metabolic stress, DNA damage, telomeres shortening, and oncogenes activation. Senescence is generally considered as a process of tumor suppression, both by preventing cancer cells proliferation and inhibiting cancer progression. It can also be a key effector mechanism for many types of anticancer therapies such as chemotherapy and radiotherapy, both directly and through bioactive molecules released by senescent cells that can stimulate an immune response. Senescence is characterized by a senescence-associated secretory phenotype (SASP) that can have both beneficial and detrimental impact on cancer progression. Despite the negatives, attempts are still being made to use senescence to fight cancer, especially when it comes to senolytics. There is a possibility that a combination of prosenescence therapy—which targets tumor cells and causes their senescence—with senotherapy—which targets senescent cells, can be promising in cancer treatment. This review provides information on cellular senescence, its connection with carcinogenesis and therapeutic possibilities linked to this process.
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Delivery of Oligonucleotides: Efficiency with Lipid Conjugation and Clinical Outcome. Pharmaceutics 2022; 14:pharmaceutics14020342. [PMID: 35214074 PMCID: PMC8879684 DOI: 10.3390/pharmaceutics14020342] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Revised: 01/24/2022] [Accepted: 01/27/2022] [Indexed: 11/21/2022] Open
Abstract
Oligonucleotides have shifted drug discovery into a new paradigm due to their ability to silence the genes and inhibit protein translation. Importantly, they can drug the un-druggable targets from the conventional small-molecule perspective. Unfortunately, poor cellular permeability and susceptibility to nuclease degradation remain as major hurdles for the development of oligonucleotide therapeutic agents. Studies of safe and effective delivery technique with lipid bioconjugates gains attention to resolve these issues. Our review article summarizes the physicochemical effect of well-studied hydrophobic moieties to enhance the cellular entry of oligonucleotides. The structural impacts of fatty acids, cholesterol, tocopherol, and squalene on cellular internalization and membrane penetration in vitro and in vivo were discussed first. The crucial assays for delivery evaluation within this section were analyzed sequentially. Next, we provided a few successful examples of lipid-conjugated oligonucleotides advanced into clinical studies for treating patients with different medical backgrounds. Finally, we pinpointed current limitations and outlooks in this research field along with opportunities to explore new modifications and efficacy studies.
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Zhu Z, Tran H, Mathahs MM, Fink BD, Albert JA, Moninger TO, Meier JL, Li M, Schmidt WN. Zinc protoporphyrin binding to telomerase complexes and inhibition of telomerase activity. Pharmacol Res Perspect 2021; 9:e00882. [PMID: 34747573 PMCID: PMC8573827 DOI: 10.1002/prp2.882] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Accepted: 09/23/2021] [Indexed: 12/16/2022] Open
Abstract
Zinc protoporphyrin (ZnPP), a naturally occurring metalloprotoporphyrin (MPP), is currently under development as a chemotherapeutic agent although its mechanism is unclear. When tested against other MPPs, ZnPP was the most effective DNA synthesis and cellular proliferation inhibitor while promoting apoptosis in telomerase positive but not telomerase negative cells. Concurrently, ZnPP down-regulated telomerase expression and was the best overall inhibitor of telomerase activity in intact cells and cellular extracts with IC50 and EC50 values of ca 2.5 and 6 µM, respectively. The natural fluorescence properties of ZnPP enabled direct imaging in cellular fractions using non-denaturing agarose gel electrophoresis, western blots, and confocal fluorescence microscopy. ZnPP localized to large cellular complexes (>600 kD) that contained telomerase and dysskerin as confirmed with immunocomplex mobility shift, immunoprecipitation, and immunoblot analyses. Confocal fluorescence studies showed that ZnPP co-localized with telomerase reverse transcriptase (TERT) and telomeres in the nucleus of synchronized S-phase cells. ZnPP also co-localized with TERT in the perinuclear regions of log phase cells but did not co-localize with telomeres on the ends of metaphase chromosomes, a site known to be devoid of telomerase complexes. Overall, these results suggest that ZnPP does not bind to telomeric sequences per se, but alternatively, interacts with other structural components of the telomerase complex to inhibit telomerase activity. In conclusion, ZnPP actively interferes with telomerase activity in neoplastic cells, thus promoting pro-apoptotic and anti-proliferative properties. These data support further development of natural or synthetic protoporphyrins for use as chemotherapeutic agents to augment current treatment protocols for neoplastic disease.
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Affiliation(s)
- Zhaowen Zhu
- Department of Internal Medicine and Research ServiceVeterans Affairs Medical CenterIowa CityIowaUSA
- Department of Internal MedicineRoy G. and Lucille A. Carver College of MedicineUniversity of IowaIowa CityIowaUSA
| | - Huy Tran
- Department of Internal MedicineRoy G. and Lucille A. Carver College of MedicineUniversity of IowaIowa CityIowaUSA
| | - Meleah M. Mathahs
- Department of Internal Medicine and Research ServiceVeterans Affairs Medical CenterIowa CityIowaUSA
| | - Brian D. Fink
- Department of Internal Medicine and Research ServiceVeterans Affairs Medical CenterIowa CityIowaUSA
| | - John A. Albert
- Department of Internal Medicine and Research ServiceVeterans Affairs Medical CenterIowa CityIowaUSA
| | - Thomas O. Moninger
- Central Microscopy Research Facility Roy G. and Lucille A. Carver College of MedicineUniversity of IowaIowa CityIowaUSA
| | - Jeffery L. Meier
- Department of Internal Medicine and Research ServiceVeterans Affairs Medical CenterIowa CityIowaUSA
- Department of Internal MedicineRoy G. and Lucille A. Carver College of MedicineUniversity of IowaIowa CityIowaUSA
| | - Ming Li
- Department of Internal Medicine and Research ServiceVeterans Affairs Medical CenterIowa CityIowaUSA
| | - Warren N. Schmidt
- Department of Internal Medicine and Research ServiceVeterans Affairs Medical CenterIowa CityIowaUSA
- Department of Internal MedicineRoy G. and Lucille A. Carver College of MedicineUniversity of IowaIowa CityIowaUSA
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11
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Ningarhari M, Caruso S, Hirsch TZ, Bayard Q, Franconi A, Védie AL, Noblet B, Blanc JF, Amaddeo G, Ganne N, Ziol M, Paradis V, Guettier C, Calderaro J, Morcrette G, Kim Y, MacLeod AR, Nault JC, Rebouissou S, Zucman-Rossi J. Telomere length is key to hepatocellular carcinoma diversity and telomerase addiction is an actionable therapeutic target. J Hepatol 2021; 74:1155-1166. [PMID: 33338512 DOI: 10.1016/j.jhep.2020.11.052] [Citation(s) in RCA: 52] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Revised: 11/17/2020] [Accepted: 11/20/2020] [Indexed: 12/24/2022]
Abstract
BACKGROUND & AIMS Telomerase activation is the earliest event in hepatocellular carcinoma (HCC) development. Thus, we aimed to elucidate the role of telomere length maintenance during liver carcinogenesis. METHODS Telomere length was measured in the tumor and non-tumor liver tissues of 1,502 patients (978 with HCC) and integrated with TERT alterations and expression, as well as clinical and molecular (analyzed by genome, exome, targeted and/or RNA-sequencing) features of HCC. The preclinical efficacy of anti-TERT antisense oligonucleotides (ASO) was assessed in vitro in 26 cell lines and in vivo in a xenograft mouse model. RESULTS Aging, liver fibrosis, male sex and excessive alcohol consumption were independent determinants of liver telomere attrition. HCC that developed in livers with long telomeres frequently had wild-type TERT with progenitor features and BAP1 mutations. In contrast, HCC that developed on livers with short telomeres were enriched in the non-proliferative HCC class and frequently had somatic TERT promoter mutations. In HCCs, telomere length is stabilized in a narrow biological range around 5.7 kb, similar to non-tumor livers, by various mechanisms that activate TERT expression. Long telomeres are characteristic of very aggressive HCCs, associated with the G3 transcriptomic subclass, TP53 alterations and poor prognosis. In HCC cell lines, TERT silencing with ASO was efficient in highly proliferative and poorly differentiated cells. Treatment for 3 to 16 weeks induced cell proliferation arrest in 12 cell lines through telomere shortening, DNA damage and activation of apoptosis. The therapeutic effect was also obtained in a xenograft mouse model. CONCLUSIONS Telomere maintenance in HCC carcinogenesis is diverse, and is associated with tumor progression and aggressiveness. The efficacy of anti-TERT ASO treatment in cell lines revealed the oncogenic addiction to TERT in HCC, providing a preclinical rationale for anti-TERT ASO treatment in HCC clinical trials. LAY SUMMARY Telomeres are repeated DNA sequences that protect chromosomes and naturally shorten in most adult cells because of the inactivation of the TERT gene, coding for the telomerase enzyme. Here we show that telomere attrition in the liver, modulated by aging, sex, fibrosis and alcohol, associates with specific clinical and molecular features of hepatocellular carcinoma, the most frequent primary liver cancer. We also show that liver cancer is dependent on TERT reactivation and telomere maintenance, which could be targeted through a novel therapeutic approach called antisense oligonucleotides.
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Affiliation(s)
- Massih Ningarhari
- Centre de Recherche des Cordeliers, Sorbonne Université, Inserm, Université de Paris, F-75006, Paris, France; Functional Genomics of Solid Tumors laboratory, Équipe labellisée Ligue Nationale contre le Cancer, Labex OncoImmunology, F-75006, Paris, France
| | - Stefano Caruso
- Centre de Recherche des Cordeliers, Sorbonne Université, Inserm, Université de Paris, F-75006, Paris, France; Functional Genomics of Solid Tumors laboratory, Équipe labellisée Ligue Nationale contre le Cancer, Labex OncoImmunology, F-75006, Paris, France
| | - Théo Z Hirsch
- Centre de Recherche des Cordeliers, Sorbonne Université, Inserm, Université de Paris, F-75006, Paris, France; Functional Genomics of Solid Tumors laboratory, Équipe labellisée Ligue Nationale contre le Cancer, Labex OncoImmunology, F-75006, Paris, France
| | - Quentin Bayard
- Centre de Recherche des Cordeliers, Sorbonne Université, Inserm, Université de Paris, F-75006, Paris, France; Functional Genomics of Solid Tumors laboratory, Équipe labellisée Ligue Nationale contre le Cancer, Labex OncoImmunology, F-75006, Paris, France
| | - Andrea Franconi
- Centre de Recherche des Cordeliers, Sorbonne Université, Inserm, Université de Paris, F-75006, Paris, France; Functional Genomics of Solid Tumors laboratory, Équipe labellisée Ligue Nationale contre le Cancer, Labex OncoImmunology, F-75006, Paris, France
| | - Anne-Laure Védie
- Centre de Recherche des Cordeliers, Sorbonne Université, Inserm, Université de Paris, F-75006, Paris, France; Functional Genomics of Solid Tumors laboratory, Équipe labellisée Ligue Nationale contre le Cancer, Labex OncoImmunology, F-75006, Paris, France
| | - Bénédicte Noblet
- Centre de Recherche des Cordeliers, Sorbonne Université, Inserm, Université de Paris, F-75006, Paris, France; Functional Genomics of Solid Tumors laboratory, Équipe labellisée Ligue Nationale contre le Cancer, Labex OncoImmunology, F-75006, Paris, France
| | - Jean-Frédéric Blanc
- Service Hépato-Gastroentérologie et Oncologie Digestive, Hôpital Haut-Lévêque, CHU de Bordeaux, F-33000, Bordeaux, France; Service de Pathologie, Hôpital Pellegrin, CHU de Bordeaux, F-33076, Bordeaux, France; Université Bordeaux, Inserm, Research in Translational Oncology, BaRITOn, F-33076, Bordeaux, France
| | - Giuliana Amaddeo
- Service d'Hépato-Gastro-Entérologie, Hôpital Henri Mondor, APHP, Université Paris Est Créteil, Inserm U955, Institut Mondor de Recherche Biomédicale, F-94010, Créteil, France
| | - Nathalie Ganne
- Centre de Recherche des Cordeliers, Sorbonne Université, Inserm, Université de Paris, F-75006, Paris, France; Functional Genomics of Solid Tumors laboratory, Équipe labellisée Ligue Nationale contre le Cancer, Labex OncoImmunology, F-75006, Paris, France; Service d'Hépatologie, Hôpital Jean Verdier, Hôpitaux Universitaires Paris-Seine-Saint-Denis, APHP, F-93140, Bondy, France
| | - Marianne Ziol
- Centre de Recherche des Cordeliers, Sorbonne Université, Inserm, Université de Paris, F-75006, Paris, France; Functional Genomics of Solid Tumors laboratory, Équipe labellisée Ligue Nationale contre le Cancer, Labex OncoImmunology, F-75006, Paris, France; Service d'Anatomo-Pathologie, Hôpital Jean Verdier, Hôpitaux Universitaires Paris-Seine-Saint-Denis, APHP, F-93140, Bondy, France
| | - Valérie Paradis
- Service de Pathologie, Hôpital Beaujon, APHP, F-92110, Clichy, France; Université Paris Diderot, CNRS, Centre de Recherche sur l'Inflammation (CRI), Paris, F-75890, France
| | - Catherine Guettier
- Service d'Anatomie Pathologique, CHU Bicêtre, APHP, F-94270, Le Kremlin-Bicêtre, France
| | - Julien Calderaro
- Service d'Anatomopathologie, Hôpital Henri Mondor, APHP, Institut Mondor de Recherche Biomédicale, F-94010, Créteil, France
| | - Guillaume Morcrette
- Service de Pathologie Pédiatrique, Assistance Publique Hôpitaux de Paris, Hôpital Robert Debré, F-75019, Paris, France
| | | | | | - Jean-Charles Nault
- Centre de Recherche des Cordeliers, Sorbonne Université, Inserm, Université de Paris, F-75006, Paris, France; Functional Genomics of Solid Tumors laboratory, Équipe labellisée Ligue Nationale contre le Cancer, Labex OncoImmunology, F-75006, Paris, France; Service d'Hépatologie, Hôpital Jean Verdier, Hôpitaux Universitaires Paris-Seine-Saint-Denis, APHP, F-93140, Bondy, France.
| | - Sandra Rebouissou
- Centre de Recherche des Cordeliers, Sorbonne Université, Inserm, Université de Paris, F-75006, Paris, France; Functional Genomics of Solid Tumors laboratory, Équipe labellisée Ligue Nationale contre le Cancer, Labex OncoImmunology, F-75006, Paris, France.
| | - Jessica Zucman-Rossi
- Centre de Recherche des Cordeliers, Sorbonne Université, Inserm, Université de Paris, F-75006, Paris, France; Functional Genomics of Solid Tumors laboratory, Équipe labellisée Ligue Nationale contre le Cancer, Labex OncoImmunology, F-75006, Paris, France; Hôpital Européen Georges Pompidou, APHP, F-75015, Paris, France.
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12
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Relitti N, Saraswati AP, Federico S, Khan T, Brindisi M, Zisterer D, Brogi S, Gemma S, Butini S, Campiani G. Telomerase-based Cancer Therapeutics: A Review on their Clinical Trials. Curr Top Med Chem 2020; 20:433-457. [PMID: 31894749 DOI: 10.2174/1568026620666200102104930] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Revised: 12/02/2019] [Accepted: 12/03/2019] [Indexed: 12/11/2022]
Abstract
Telomeres are protective chromosomal ends that shield the chromosomes from DNA damage, exonucleolytic degradation, recombination, and end-to-end fusion. Telomerase is a ribonucleoprotein that adds TTAGGG tandem repeats to the telomeric ends. It has been observed that 85 to 90% of human tumors express high levels of telomerase, playing a crucial role in the development of cancers. Interestingly, the telomerase activity is generally absent in normal somatic cells. This selective telomerase expression has driven scientists to develop novel anti-cancer therapeutics with high specificity and potency. Several advancements have been made in this area, which is reflected by the enormous success of the anticancer agent Imetelstat. Since the discovery of Imetelstat, several research groups have contributed to enrich the therapeutic arsenal against cancer. Such contributions include the application of new classes of small molecules, peptides, and hTERT-based immunotherapeutic agents (p540, GV1001, GRNVAC1 or combinations of these such as Vx-001). Many of these therapeutic tools are under different stages of clinical trials and have shown promising outcomes. In this review, we highlight the current status of telomerase-based cancer therapeutics and the outcome of these investigations.
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Affiliation(s)
- Nicola Relitti
- Department of Biotechnology, Chemistry and Pharmacy, Department of Excellence 2018-2022, via Aldo Moro 2, I- 53100 Siena, University of Siena, Siena, Italy
| | - Akella P Saraswati
- Department of Biotechnology, Chemistry and Pharmacy, Department of Excellence 2018-2022, via Aldo Moro 2, I- 53100 Siena, University of Siena, Siena, Italy
| | - Stefano Federico
- Department of Biotechnology, Chemistry and Pharmacy, Department of Excellence 2018-2022, via Aldo Moro 2, I- 53100 Siena, University of Siena, Siena, Italy
| | - Tuhina Khan
- Department of Biotechnology, Chemistry and Pharmacy, Department of Excellence 2018-2022, via Aldo Moro 2, I- 53100 Siena, University of Siena, Siena, Italy
| | - Margherita Brindisi
- Department of Pharmacy, Department of Excellence 2018-2022, University of Napoli Federico II, via D. Montesano 49, I-80131 Napoli, Italy
| | - Daniela Zisterer
- School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, 152-160, Pearse Street, Dublin 2, Ireland
| | - Simone Brogi
- Department of Pharmacy, University of Pisa, via Bonanno Pisano 6, I-56126 Pisa, Italy
| | - Sandra Gemma
- Department of Biotechnology, Chemistry and Pharmacy, Department of Excellence 2018-2022, via Aldo Moro 2, I- 53100 Siena, University of Siena, Siena, Italy
| | - Stefania Butini
- Department of Biotechnology, Chemistry and Pharmacy, Department of Excellence 2018-2022, via Aldo Moro 2, I- 53100 Siena, University of Siena, Siena, Italy
| | - Giuseppe Campiani
- Department of Biotechnology, Chemistry and Pharmacy, Department of Excellence 2018-2022, via Aldo Moro 2, I- 53100 Siena, University of Siena, Siena, Italy
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13
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Garcia-Lezana T, Lopez-Canovas JL, Villanueva A. Signaling pathways in hepatocellular carcinoma. Adv Cancer Res 2020; 149:63-101. [PMID: 33579428 DOI: 10.1016/bs.acr.2020.10.002] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Despite the recent introduction of new effective systemic agents, the survival of patients with hepatocellular carcinoma (HCC) at advanced stages remains dismal. This underscores the need for new therapies, which has spurred extensive research on the identification of the main drivers of pathway de-regulation as a source of novel therapeutic targets. Frequently altered pathways in HCC involve growth factor receptors (e.g., VEGFR, FGFR, TGFA, EGFR, IGFR) and/or its cytoplasmic intermediates (e.g., PI3K-AKT-mTOR, RAF/ERK/MAPK) as well as key pathways in cell differentiation (e.g., Wnt/β-catenin, JAK/STAT, Hippo, Hedgehog, Notch). Somatic mutations, chromosomal aberrations and epigenetic changes are common mechanisms for pathway deregulation in HCC. Aberrant pathway activation has also been explored as a biomarker to predict response to specific therapies, but currently, these strategies are not implemented when deciding systemic therapies in HCC patients. Beyond the well-established molecular cascades, there are numerous emerging signaling pathways also deregulated in HCC (e.g., tumor microenvironment, non-coding RNA, intestinal microbiota), which have opened new avenues for therapeutic exploration.
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Affiliation(s)
- Teresa Garcia-Lezana
- Division of Liver Diseases, Liver Cancer Program, Department of Medicine, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Juan Luis Lopez-Canovas
- Department of Cell Biology, Physiology and Immunology, Maimonides Institute of Biomedical Research of Córdoba (IMIBIC), University of Córdoba, Córdoba, Spain
| | - Augusto Villanueva
- Division of Liver Diseases, Liver Cancer Program, Department of Medicine, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY, United States; Division of Hematology and Medical Oncology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, United States.
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14
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Hidaka D, Onozawa M, Miyashita N, Yokoyama S, Nakagawa M, Hashimoto D, Teshima T. Short-term treatment with imetelstat sensitizes hematopoietic malignant cells to a genotoxic agent via suppression of the telomerase-mediated DNA repair process. Leuk Lymphoma 2020; 61:2722-2732. [PMID: 32571117 DOI: 10.1080/10428194.2020.1779256] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Imetelstat is a specific and competitive inhibitor of telomerase enzymatic activity. We demonstrated that imetelstat could interfere with the DNA repair process and enhance the effect of DNA damaging agents using hematological tumor cell lines. Short-term administration of imetelstat enhanced growth suppression by anticancer agents and radiation. It also upregulated γH2AX expression induced by irradiation. Immunofluorescence staining showed that both human telomerase reverse transcriptase (hTERT) and γH2AX were upregulated and co-localized in the nucleus of peripheral blood mononuclear cells after irradiation, suggesting that hTERT was involved in the DNA-DSB repair process. Imetelstat enhanced growth inhibitory effect of cytotoxic agents in short-term culture without shortening of telomeres, indicating that this effect was attributed by telomere length independent mechanism. Our results suggest that the combination of short-term treatment with imetelstat and cytotoxic agent is a promising strategy to treat a wide variety of hematopoietic malignancies.
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Affiliation(s)
- Daisuke Hidaka
- Department of Hematology, Hokkaido University Faculty of Medicine, Graduate School of Medicine, Sapporo, Japan
| | - Masahiro Onozawa
- Department of Hematology, Hokkaido University Faculty of Medicine, Graduate School of Medicine, Sapporo, Japan
| | - Naohiro Miyashita
- Department of Hematology, Hokkaido University Faculty of Medicine, Graduate School of Medicine, Sapporo, Japan
| | - Shota Yokoyama
- Department of Hematology, Hokkaido University Faculty of Medicine, Graduate School of Medicine, Sapporo, Japan
| | - Masao Nakagawa
- Department of Hematology, Hokkaido University Faculty of Medicine, Graduate School of Medicine, Sapporo, Japan
| | - Daigo Hashimoto
- Department of Hematology, Hokkaido University Faculty of Medicine, Graduate School of Medicine, Sapporo, Japan
| | - Takanori Teshima
- Department of Hematology, Hokkaido University Faculty of Medicine, Graduate School of Medicine, Sapporo, Japan
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15
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Ozcan M, Altay O, Lam S, Turkez H, Aksoy Y, Nielsen J, Uhlen M, Boren J, Mardinoglu A. Improvement in the Current Therapies for Hepatocellular Carcinoma Using a Systems Medicine Approach. ACTA ACUST UNITED AC 2020; 4:e2000030. [PMID: 32529800 DOI: 10.1002/adbi.202000030] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Revised: 03/02/2020] [Accepted: 03/09/2020] [Indexed: 12/24/2022]
Abstract
Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related death primarily due to the lack of effective targeted therapies. Despite the distinct morphological and phenotypic patterns of HCC, treatment strategies are restricted to relatively homogeneous therapies, including multitargeted tyrosine kinase inhibitors and immune checkpoint inhibitors. Therefore, more effective therapy options are needed to target dysregulated metabolic and molecular pathways in HCC. Integrative genomic profiling of HCC patients provides insight into the most frequently mutated genes and molecular targets, including telomerase reverse transcriptase, the TP53 gene, and the Wnt/β-catenin signaling pathway oncogene (CTNNB1). Moreover, emerging techniques, such as genome-scale metabolic models may elucidate the underlying cancer-specific metabolism, which allows for the discovery of potential drug targets and identification of biomarkers. De novo lipogenesis has been revealed as consistently upregulated since it is required for cell proliferation in all HCC patients. The metabolic network-driven stratification of HCC patients in terms of redox responses, utilization of metabolites, and subtype-specific pathways may have clinical implications to drive the development of personalized medicine. In this review, the current and emerging therapeutic targets in light of molecular approaches and metabolic network-based strategies are summarized, prompting effective treatment of HCC patients.
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Affiliation(s)
- Mehmet Ozcan
- Science for Life Laboratory, KTH - Royal Institute of Technology, Stockholm, SE 17121, Sweden.,Department of Medical Biochemistry, Faculty of Medicine, Hacettepe University, Ankara, 06100, Turkey
| | - Ozlem Altay
- Science for Life Laboratory, KTH - Royal Institute of Technology, Stockholm, SE 17121, Sweden
| | - Simon Lam
- Centre for Host-Microbiome Interactions, Faculty of Dentistry, Oral & Craniofacial Sciences, King's College London, London, SE1 9RT, UK
| | - Hasan Turkez
- Department of Medical Biology, Faculty of Medicine, Atatürk University, Erzurum, 25240, Turkey
| | - Yasemin Aksoy
- Department of Medical Biochemistry, Faculty of Medicine, Hacettepe University, Ankara, 06100, Turkey
| | - Jens Nielsen
- Prof. J. Nielsen, Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, SE-41296, Sweden
| | - Mathias Uhlen
- Science for Life Laboratory, KTH - Royal Institute of Technology, Stockholm, SE 17121, Sweden
| | - Jan Boren
- Department of Molecular and Clinical Medicine, University of Gothenburg, The Wallenberg Laboratory, Sahlgrenska University Hospital, Gothenburg, SE-413 45, Sweden
| | - Adil Mardinoglu
- Science for Life Laboratory, KTH - Royal Institute of Technology, Stockholm, SE 17121, Sweden.,Centre for Host-Microbiome Interactions, Faculty of Dentistry, Oral & Craniofacial Sciences, King's College London, London, SE1 9RT, UK
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16
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Wu Y, Zhong D, Li Y, Wu H, Xu X, Yang J, Gu Z. Tumor-Oriented Telomerase-Terminated Nanoplatform as Versatile Strategy for Multidrug Resistance Reversal in Cancer Treatment. Adv Healthc Mater 2020; 9:e1901739. [PMID: 32125789 DOI: 10.1002/adhm.201901739] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 02/08/2020] [Accepted: 02/10/2020] [Indexed: 02/05/2023]
Abstract
Multidrug resistance is one of the major problems in chemotherapy, and exploiting impactful targets to reverse drug resistance of most tumors remains a difficult problem. In this study, the tumor-oriented nanoparticle, BIBR1532-loaded peptide dendrimeric prodrug nanoassembly (B-PDPN), is used to assist telomerase inhibition for multidrug resistance reversal. B-PDPN possesses the characteristics of an acid-activated histidine to promote cellular uptake, a redox-sensitive poly(ethylene glycol) (PEG) layer to actualize endosomal escape and telomerase inhibitor release, and an acid sensitive chemical bond to facilitate chemotherapeutic drug release. Telomerase termination weakens the protective effect of hTERT protein on mitochondria and enhances reactive oxygen species (ROS) production, which increases DNA damage and apoptosis. The tumor-oriented nanoparticle B-PDPN achieves a broad-spectrum telomerase inhibition to combat multidrug resistance. In vivo experiments support the evidence that B-PDPN accumulates in the tumor site and reduces the expression of hTERT in tumor tissues to inhibit drug resistant tumor growth. This work introduces an innovative strategy of utilizing features of tumor-activated nanoplatform to assist telomerase termination. The nanoplatform enhances intracellular drug concentration and nucleus delivery of doxorubicin (DOX), and promotes DNA damage to combat multidrug resistance.
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Affiliation(s)
- Yahui Wu
- Huaxi MR Research Center (HMRRC)Department of RadiologyFunctional and Molecular Imaging Key Laboratory of Sichuan ProvinceWest China Hospital, and National Engineering Research Center for BiomaterialsSichuan University Chengdu 610041 P. R. China
- College of Life SciencesSichuan University Chengdu 610064 P. R. China
| | - Dan Zhong
- Huaxi MR Research Center (HMRRC)Department of RadiologyFunctional and Molecular Imaging Key Laboratory of Sichuan ProvinceWest China Hospital, and National Engineering Research Center for BiomaterialsSichuan University Chengdu 610041 P. R. China
| | - Yachao Li
- Huaxi MR Research Center (HMRRC)Department of RadiologyFunctional and Molecular Imaging Key Laboratory of Sichuan ProvinceWest China Hospital, and National Engineering Research Center for BiomaterialsSichuan University Chengdu 610041 P. R. China
| | - Huayu Wu
- Huaxi MR Research Center (HMRRC)Department of RadiologyFunctional and Molecular Imaging Key Laboratory of Sichuan ProvinceWest China Hospital, and National Engineering Research Center for BiomaterialsSichuan University Chengdu 610041 P. R. China
| | - Xianghui Xu
- College of Materials Science and EngineeringNanjing Tech University Nanjing 211816 P. R. China
| | - Jun Yang
- The Key Laboratory of Bioactive MaterialsMinistry of EducationCollege of Life ScienceNankai University Tianjin 300071 P. R. China
| | - Zhongwei Gu
- Huaxi MR Research Center (HMRRC)Department of RadiologyFunctional and Molecular Imaging Key Laboratory of Sichuan ProvinceWest China Hospital, and National Engineering Research Center for BiomaterialsSichuan University Chengdu 610041 P. R. China
- College of Materials Science and EngineeringNanjing Tech University Nanjing 211816 P. R. China
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17
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Günes C, Wezel F, Southgate J, Bolenz C. Implications of TERT promoter mutations and telomerase activity in urothelial carcinogenesis. Nat Rev Urol 2019; 15:386-393. [PMID: 29599449 DOI: 10.1038/s41585-018-0001-5] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Telomerase activity imparts eukaryotic cells with unlimited proliferation capacity, one of the cancer hallmarks. Over 90% of human urothelial carcinoma of the bladder (UCB) tumours are positive for telomerase activity. Telomerase activation can occur through several mechanisms. Mutations in the core promoter region of the human telomerase reverse transcriptase gene (TERT) cause telomerase reactivation in 60-80% of UCBs, whereas the prevalence of these mutations is lower in urothelial cancers of other origins. TERT promoter mutations are the most frequent genetic alteration across all stages of UCB, indicating a strong selection pressure during neoplastic transformation. TERT promoter mutations could arise during regeneration of normal urothelium and, owing to consequential telomerase reactivation, might be the basis of UCB initiation, which represents a new model of urothelial cancer origination. In the future, TERT promoter mutations and telomerase activity might have diagnostic and therapeutic applications in UCB.
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Affiliation(s)
- Cagatay Günes
- Department of Urology, University of Ulm, Ulm, Germany.
| | - Felix Wezel
- Department of Urology, University of Ulm, Ulm, Germany
| | - Jennifer Southgate
- Department of Biology, Jack Birch Unit of Molecular Carcinogenesis, University of York, York, UK
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18
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The role of telomeres and telomerase in cirrhosis and liver cancer. Nat Rev Gastroenterol Hepatol 2019; 16:544-558. [PMID: 31253940 DOI: 10.1038/s41575-019-0165-3] [Citation(s) in RCA: 275] [Impact Index Per Article: 55.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 05/21/2019] [Indexed: 12/12/2022]
Abstract
Telomerase is a key enzyme for cell survival that prevents telomere shortening and the subsequent cellular senescence that is observed after many rounds of cell division. In contrast, inactivation of telomerase is observed in most cells of the adult liver. Absence of telomerase activity and shortening of telomeres has been implicated in hepatocyte senescence and the development of cirrhosis, a chronic liver disease that can lead to hepatocellular carcinoma (HCC) development. During hepatocarcinogenesis, telomerase reactivation is required to enable the uncontrolled cell proliferation that leads to malignant transformation and HCC development. Part of the telomerase complex, telomerase reverse transcriptase, is encoded by TERT, and several mechanisms of telomerase reactivation have been described in HCC that include somatic TERT promoter mutations, TERT amplification, TERT translocation and viral insertion into the TERT gene. An understanding of the role of telomeres and telomerase in HCC development is important to develop future targeted therapies and improve survival of this disease. In this Review, the roles of telomeres and telomerase in liver carcinogenesis are discussed, in addition to their potential translation to clinical practice as biomarkers and therapeutic targets.
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19
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Imetelstat, a telomerase inhibitor, is capable of depleting myelofibrosis stem and progenitor cells. Blood Adv 2019; 2:2378-2388. [PMID: 30242099 DOI: 10.1182/bloodadvances.2018022012] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Accepted: 08/18/2018] [Indexed: 01/26/2023] Open
Abstract
Clinical trials of imetelstat therapy have indicated that this telomerase inhibitor might have disease-modifying effects in a subset of patients with myelofibrosis (MF). The mechanism by which imetelstat induces such clinical responses has not been clearly elucidated. Using in vitro hematopoietic progenitor cell (HPC) assays and in vivo hematopoietic stem cell (HSC) assays, we examined the effects of imetelstat on primary normal and MF HSCs/HPCs. Treatment of CD34+ cells with imetelstat reduced the numbers of MF but not cord blood HPCs (colony-forming unit-granulocyte/macrophage, burst-forming unit-erythroid, and colony-forming unit-granulocyte/erythroid/macrophage/megakaryocyte) as well as MF but not normal CD34+ALDH+ cells irrespective of the patient's mutational status. Moreover, imetelstat treatment resulted in depletion of mutated HPCs from JAK2V617F+ MF patients. Furthermore, treatment of immunodeficient mice that had been previously transplanted with MF splenic CD34+ cells with imetelstat at a dose of 15 mg/kg, 3 times per week for 4 weeks had a limited effect on the degree of chimerism achieved by normal severe combined immunodeficiency repopulating cells but resulted in a significant reduction in the degree of human MF cell chimerism as well as the proportion of mutated donor cells. These effects were sustained for at least 3 months after drug treatment was discontinued. These actions of imetelstat on MF HSCs/HPCs were associated with inhibition of telomerase activity and the induction of apoptosis. Our findings indicate that the effects of imetelstat therapy observed in MF patients are likely attributable to the greater sensitivity of imetelstat against MF as compared with normal HSCs/HPCs as well as the intensity of the imetelstat dose schedule.
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20
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Stem J, Flickinger JC, Merlino D, Caparosa EM, Snook AE, Waldman SA. Therapeutic targeting of gastrointestinal cancer stem cells. Regen Med 2019; 14:331-343. [PMID: 31025613 DOI: 10.2217/rme-2018-0146] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Gastrointestinal cancers remain a tremendous burden on society. Despite advances in therapy options, including chemotherapy and radiation, cancer mortality from recurrences and metastases occur frequently. Cancer stem cells (CSCs) drive disease recurrence and metastasis, as these cells are uniquely equipped to self-renew and evade therapy. Therefore, cancer eradication requires treatment strategies that target CSCs in addition to differentiated cancer cells. This review highlights current literature on therapies targeting CSCs in gastrointestinal cancer.
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Affiliation(s)
- Jonathan Stem
- Departments of Surgery, Sidney, 1020 Locust St, JAH368, Philadelphia, PA 19107, USA
| | - John C Flickinger
- Pharmacology & Experimental Therapeutics, Sidney, 1020 Locust St, JAH368, Philadelphia, PA 19107, USA
| | - Dante Merlino
- Pharmacology & Experimental Therapeutics, Sidney, 1020 Locust St, JAH368, Philadelphia, PA 19107, USA
| | - Ellen M Caparosa
- Departments of Surgery, Sidney, 1020 Locust St, JAH368, Philadelphia, PA 19107, USA.,Pharmacology & Experimental Therapeutics, Sidney, 1020 Locust St, JAH368, Philadelphia, PA 19107, USA
| | - Adam E Snook
- Pharmacology & Experimental Therapeutics, Sidney, 1020 Locust St, JAH368, Philadelphia, PA 19107, USA
| | - Scott A Waldman
- Pharmacology & Experimental Therapeutics, Sidney, 1020 Locust St, JAH368, Philadelphia, PA 19107, USA
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21
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Zhu J, Liu W, Chen C, Zhang H, Yue D, Li C, Zhang L, Gao L, Huo Y, Liu C, Giaccone G, Zhang B, Wang C. TPP1 OB-fold domain protein suppresses cell proliferation and induces cell apoptosis by inhibiting telomerase recruitment to telomeres in human lung cancer cells. J Cancer Res Clin Oncol 2019; 145:1509-1519. [PMID: 31016380 DOI: 10.1007/s00432-019-02921-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Accepted: 04/16/2019] [Indexed: 11/29/2022]
Abstract
PURPOSE Maintaining telomeres by recruiting telomerase-to-chromosome ends is essential for cancer cell survival. Inhibiting telomerase recruitment to telomeres represents a novel strategy for telomere-based lung cancer therapy. However, approaches for interrupting telomerase recruitment for cancer therapy still need to be explored. METHODS The telomere-binding protein TPP1 is responsible for recruiting telomerase to telomeres and synthesizing telomeres through the association between the oligosaccharide/oligonucleotide-binding (OB)-fold domain of TPP1 and telomerase reverse transcriptase. We overexpressed the TPP1 OB domain (TPP1-OB) by lentivirus infection in lung cancer cells. Telomere length was examined by Southern blot analysis of terminal restriction fragments. The effects of TPP1-OB on cell proliferation, the cell cycle, apoptosis, chemosensitivity, and tumor growth were evaluated in vitro and in vivo. RESULT TPP1-OB inhibited the recruitment of telomerase to telomeres and shortened telomere length by acting as a dominant-negative mutant of TPP1. TPP1-OB resulted in reduced cell proliferation, G1 cell cycle arrest, and increased cell apoptosis in lung cancer cells. Cell apoptosis occurred mainly through the caspase-3-dependent signaling pathway. TPP1-OB also suppressed anchorage-independent growth and tumor growth in vivo. Moreover, we demonstrated that TPP1-OB enhances the sensitivity of lung cancer cells to the chemotherapeutic drug paclitaxel. CONCLUSION Our results suggest that inhibiting TPP1-mediated telomerase recruitment by expressing the TPP1-OB domain is a potential novel strategy for telomere-targeted lung cancer therapy.
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Affiliation(s)
- Jinfang Zhu
- Department of Lung Cancer, Tianjin Lung Cancer Center, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin's Clinical Research Center for Cancer, Huan-Hu-Xi Road, Ti-Yuan-Bei, He Xi District, Tianjin, 300060, China
| | - Weiran Liu
- Department of Anesthesiology, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin's Clinical Research Center for Cancer, Tianjin, China
| | - Chen Chen
- Department of Lung Cancer, Tianjin Lung Cancer Center, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin's Clinical Research Center for Cancer, Huan-Hu-Xi Road, Ti-Yuan-Bei, He Xi District, Tianjin, 300060, China
| | - Hua Zhang
- Department of Lung Cancer, Tianjin Lung Cancer Center, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin's Clinical Research Center for Cancer, Huan-Hu-Xi Road, Ti-Yuan-Bei, He Xi District, Tianjin, 300060, China
| | - Dongsheng Yue
- Department of Lung Cancer, Tianjin Lung Cancer Center, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin's Clinical Research Center for Cancer, Huan-Hu-Xi Road, Ti-Yuan-Bei, He Xi District, Tianjin, 300060, China
| | - Chenguang Li
- Department of Lung Cancer, Tianjin Lung Cancer Center, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin's Clinical Research Center for Cancer, Huan-Hu-Xi Road, Ti-Yuan-Bei, He Xi District, Tianjin, 300060, China
| | - Lianmin Zhang
- Department of Lung Cancer, Tianjin Lung Cancer Center, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin's Clinical Research Center for Cancer, Huan-Hu-Xi Road, Ti-Yuan-Bei, He Xi District, Tianjin, 300060, China
| | - Liuwei Gao
- Department of Lung Cancer, Tianjin Lung Cancer Center, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin's Clinical Research Center for Cancer, Huan-Hu-Xi Road, Ti-Yuan-Bei, He Xi District, Tianjin, 300060, China
| | - Yansong Huo
- Department of Lung Cancer, Tianjin Lung Cancer Center, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin's Clinical Research Center for Cancer, Huan-Hu-Xi Road, Ti-Yuan-Bei, He Xi District, Tianjin, 300060, China
| | - Chang Liu
- Department of Lung Cancer, Tianjin Lung Cancer Center, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin's Clinical Research Center for Cancer, Huan-Hu-Xi Road, Ti-Yuan-Bei, He Xi District, Tianjin, 300060, China
| | - Giuseppe Giaccone
- Department of Lung Cancer, Tianjin Lung Cancer Center, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin's Clinical Research Center for Cancer, Huan-Hu-Xi Road, Ti-Yuan-Bei, He Xi District, Tianjin, 300060, China.,Georgetown University, Washington, DC, USA
| | - Bin Zhang
- Department of Lung Cancer, Tianjin Lung Cancer Center, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin's Clinical Research Center for Cancer, Huan-Hu-Xi Road, Ti-Yuan-Bei, He Xi District, Tianjin, 300060, China.
| | - Changli Wang
- Department of Lung Cancer, Tianjin Lung Cancer Center, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin's Clinical Research Center for Cancer, Huan-Hu-Xi Road, Ti-Yuan-Bei, He Xi District, Tianjin, 300060, China.
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22
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Li CL, Li CY, Lin YY, Ho MC, Chen DS, Chen PJ, Yeh SH. Androgen Receptor Enhances Hepatic Telomerase Reverse Transcriptase Gene Transcription After Hepatitis B Virus Integration or Point Mutation in Promoter Region. Hepatology 2019; 69:498-512. [PMID: 30070724 DOI: 10.1002/hep.30201] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Accepted: 07/31/2018] [Indexed: 12/15/2022]
Abstract
The gender disparity of hepatocellular carcinoma (HCC) is most striking in hepatitis B virus (HBV)-related cases. The majority of such HCC cases contain integrated HBV, and some hotspot integrations, such as those in the telomerase reverse transcriptase gene (TERT) promoter, activate gene expression to drive carcinogenesis. As the HBV genome contains both androgen-responsive and estrogen-responsive motifs, we hypothesized that the integrated HBV DNA renders a similar regulation for downstream gene expression and thus contributes to male susceptibility to HCC. To test this hypothesis, the HBV integration sites and the common mutations in the TERT promoter and tumor protein P53 (TP53) coding region were analyzed in 101 HBV-related HCC cases using a capture-next-generation sequencing platform. The results showed that both HBV integration and -124G>A mutation in the TERT promoter region, occurring in a mutually exclusive manner, were more frequent in male than in female patients with HCC (integration: 22/58 male patients with HCC, 6/36 female patients with HCC, P = 0.0285; -124G>A: 17/62 male patients with HCC, 3/39 female patients with HCC, P = 0.0201; in combination, 39/62 male patients with HCC, 9/39 female patients with HCC, P < 0.0001). The effects of sex hormone pathways on the expression of TERT with both genetic changes were investigated using a reporter assay. HBV integration in the TERT promoter rendered the TERT transcription responsive to sex hormones, with enhancement by androgen receptor (AR) but suppression by estrogen receptor, both of which were dependent on hepatocyte nuclear factor 4 alpha. Besides, AR also increased TERT expression by targeting TERT promoter mutations in a GA binding protein transcription factor subunit alpha-dependent manner. Conclusion: TERT elevation by AR through integrated HBV and point mutation at the TERT promoter region was identified as a mechanism for the male dominance of HBV-related HCCs; telomerase and AR thus may be targets for intervention of HCC.
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Affiliation(s)
- Chiao-Ling Li
- Department of Microbiology, National Taiwan University College of Medicine and Hospital, Taipei, Taiwan
| | - Chen-Yu Li
- Department of Microbiology, National Taiwan University College of Medicine and Hospital, Taipei, Taiwan
| | - You-Yu Lin
- Graduate Institute of Clinical Medicine, National Taiwan University College of Medicine and Hospital, Taipei, Taiwan
| | - Ming-Chih Ho
- Department of Surgery, National Taiwan University College of Medicine and Hospital, Taipei, Taiwan
| | - Ding-Shinn Chen
- Graduate Institute of Clinical Medicine, National Taiwan University College of Medicine and Hospital, Taipei, Taiwan.,Department of Internal Medicine, National Taiwan University College of Medicine and Hospital, Taipei, Taiwan
| | - Pei-Jer Chen
- Graduate Institute of Clinical Medicine, National Taiwan University College of Medicine and Hospital, Taipei, Taiwan.,Department of Internal Medicine, National Taiwan University College of Medicine and Hospital, Taipei, Taiwan.,National Taiwan University Center for Genomic Medicine, National Taiwan University College of Medicine and Hospital, Taipei, Taiwan
| | - Shiou-Hwei Yeh
- Department of Microbiology, National Taiwan University College of Medicine and Hospital, Taipei, Taiwan.,National Taiwan University Center for Genomic Medicine, National Taiwan University College of Medicine and Hospital, Taipei, Taiwan.,Department of Laboratory Medicine, National Taiwan University College of Medicine and Hospital, Taipei, Taiwan
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23
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Calcinotto A, Kohli J, Zagato E, Pellegrini L, Demaria M, Alimonti A. Cellular Senescence: Aging, Cancer, and Injury. Physiol Rev 2019; 99:1047-1078. [PMID: 30648461 DOI: 10.1152/physrev.00020.2018] [Citation(s) in RCA: 653] [Impact Index Per Article: 130.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Cellular senescence is a permanent state of cell cycle arrest that occurs in proliferating cells subjected to different stresses. Senescence is, therefore, a cellular defense mechanism that prevents the cells to acquire an unnecessary damage. The senescent state is accompanied by a failure to re-enter the cell cycle in response to mitogenic stimuli, an enhanced secretory phenotype and resistance to cell death. Senescence takes place in several tissues during different physiological and pathological processes such as tissue remodeling, injury, cancer, and aging. Although senescence is one of the causative processes of aging and it is responsible of aging-related disorders, senescent cells can also play a positive role. In embryogenesis and tissue remodeling, senescent cells are required for the proper development of the embryo and tissue repair. In cancer, senescence works as a potent barrier to prevent tumorigenesis. Therefore, the identification and characterization of key features of senescence, the induction of senescence in cancer cells, or the elimination of senescent cells by pharmacological interventions in aging tissues is gaining consideration in several fields of research. Here, we describe the known key features of senescence, the cell-autonomous, and noncell-autonomous regulators of senescence, and we attempt to discuss the functional role of this fundamental process in different contexts in light of the development of novel therapeutic targets.
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Affiliation(s)
- Arianna Calcinotto
- Institute of Oncology Research (IOR), Oncology Institute of Southern Switzerland , Bellinzona , Switzerland ; University of Groningen, European Research Institute for the Biology of Ageing, University Medical Center Groningen , Groningen , The Netherlands ; IOR, Oncology Institute of Southern Switzerland , Bellinzona , Switzerland ; Università della Svizzera Italiana, Faculty of Biomedical Sciences , Lugano , Italy ; Faculty of Biology and Medicine, University of Lausanne UNIL , Lausanne , Switzerland ; and Department of Medicine, Venetian Institute of Molecular Medicine, University of Padova , Padova , Italy
| | - Jaskaren Kohli
- Institute of Oncology Research (IOR), Oncology Institute of Southern Switzerland , Bellinzona , Switzerland ; University of Groningen, European Research Institute for the Biology of Ageing, University Medical Center Groningen , Groningen , The Netherlands ; IOR, Oncology Institute of Southern Switzerland , Bellinzona , Switzerland ; Università della Svizzera Italiana, Faculty of Biomedical Sciences , Lugano , Italy ; Faculty of Biology and Medicine, University of Lausanne UNIL , Lausanne , Switzerland ; and Department of Medicine, Venetian Institute of Molecular Medicine, University of Padova , Padova , Italy
| | - Elena Zagato
- Institute of Oncology Research (IOR), Oncology Institute of Southern Switzerland , Bellinzona , Switzerland ; University of Groningen, European Research Institute for the Biology of Ageing, University Medical Center Groningen , Groningen , The Netherlands ; IOR, Oncology Institute of Southern Switzerland , Bellinzona , Switzerland ; Università della Svizzera Italiana, Faculty of Biomedical Sciences , Lugano , Italy ; Faculty of Biology and Medicine, University of Lausanne UNIL , Lausanne , Switzerland ; and Department of Medicine, Venetian Institute of Molecular Medicine, University of Padova , Padova , Italy
| | - Laura Pellegrini
- Institute of Oncology Research (IOR), Oncology Institute of Southern Switzerland , Bellinzona , Switzerland ; University of Groningen, European Research Institute for the Biology of Ageing, University Medical Center Groningen , Groningen , The Netherlands ; IOR, Oncology Institute of Southern Switzerland , Bellinzona , Switzerland ; Università della Svizzera Italiana, Faculty of Biomedical Sciences , Lugano , Italy ; Faculty of Biology and Medicine, University of Lausanne UNIL , Lausanne , Switzerland ; and Department of Medicine, Venetian Institute of Molecular Medicine, University of Padova , Padova , Italy
| | - Marco Demaria
- Institute of Oncology Research (IOR), Oncology Institute of Southern Switzerland , Bellinzona , Switzerland ; University of Groningen, European Research Institute for the Biology of Ageing, University Medical Center Groningen , Groningen , The Netherlands ; IOR, Oncology Institute of Southern Switzerland , Bellinzona , Switzerland ; Università della Svizzera Italiana, Faculty of Biomedical Sciences , Lugano , Italy ; Faculty of Biology and Medicine, University of Lausanne UNIL , Lausanne , Switzerland ; and Department of Medicine, Venetian Institute of Molecular Medicine, University of Padova , Padova , Italy
| | - Andrea Alimonti
- Institute of Oncology Research (IOR), Oncology Institute of Southern Switzerland , Bellinzona , Switzerland ; University of Groningen, European Research Institute for the Biology of Ageing, University Medical Center Groningen , Groningen , The Netherlands ; IOR, Oncology Institute of Southern Switzerland , Bellinzona , Switzerland ; Università della Svizzera Italiana, Faculty of Biomedical Sciences , Lugano , Italy ; Faculty of Biology and Medicine, University of Lausanne UNIL , Lausanne , Switzerland ; and Department of Medicine, Venetian Institute of Molecular Medicine, University of Padova , Padova , Italy
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24
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Ozcagli E, Kara M, Kotil T, Fragkiadaki P, Tzatzarakis MN, Tsitsimpikou C, Stivaktakis PD, Tsoukalas D, Spandidos DA, Tsatsakis AM, Alpertunga B. Stanozolol administration combined with exercise leads to decreased telomerase activity possibly associated with liver aging. Int J Mol Med 2018; 42:405-413. [PMID: 29717770 PMCID: PMC5979936 DOI: 10.3892/ijmm.2018.3644] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Accepted: 04/11/2018] [Indexed: 12/28/2022] Open
Abstract
Anabolic agents are doping substances which are commonly used in sports. Stanozolol, a 17α‑alkylated derivative of testosterone, has a widespread use among athletes and bodybuilders. Several medical and behavioral adverse effects are associated with anabolic androgenic steroids (AAS) abuse, while the liver remains the most well recognized target organ. In the present study, the hepatic effects of stanozolol administration in rats at high doses resembling those used for doping purposes were investigated, in the presence or absence of exercise. Stanozolol and its metabolites, 16‑β‑hydroxystanozolol and 3'‑hydroxystanozolol, were detected in rat livers using liquid chromatography‑mass spectrometry (LC‑MS). Telomerase activity, which is involved in cellular aging and tumorigenesis, was detected by examining telomerase reverse transcriptase (TERT) and phosphatase and tensin homolog (PTEN) expression levels in the livers of stanozolol‑treated rats. Stanozolol induced telomerase activity at the molecular level in the liver tissue of rats and exercise reversed this induction, reflecting possible premature liver tissue aging. PTEN gene expression in the rat livers was practically unaffected either by exercise or by stanozolol administration.
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Affiliation(s)
- Eren Ozcagli
- Department of Pharmaceutical Toxicology, Faculty of Pharmacy and
| | - Mehtap Kara
- Department of Pharmaceutical Toxicology, Faculty of Pharmacy and
| | - Tugba Kotil
- Department of Histology and Embryology, Faculty of Medicine, Istanbul University, Istanbul 34116, Turkey
| | - Persefoni Fragkiadaki
- Laboratory of Forensic Sciences and Toxicology, Medical School, University of Crete, 71003 Heraklion
| | - Manolis N. Tzatzarakis
- Laboratory of Forensic Sciences and Toxicology, Medical School, University of Crete, 71003 Heraklion
| | | | | | - Dimitrios Tsoukalas
- Laboratory of Forensic Sciences and Toxicology, Medical School, University of Crete, 71003 Heraklion
| | - Demetrios A. Spandidos
- Laboratory of Clinical Virology, Medical School, University of Crete, 71003 Heraklion, Greece
| | - Aristides M. Tsatsakis
- Laboratory of Forensic Sciences and Toxicology, Medical School, University of Crete, 71003 Heraklion
| | - Buket Alpertunga
- Department of Pharmaceutical Toxicology, Faculty of Pharmacy and
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25
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Sengupta S, Sobo M, Lee K, Senthil Kumar S, White AR, Mender I, Fuller C, Chow LML, Fouladi M, Shay JW, Drissi R. Induced Telomere Damage to Treat Telomerase Expressing Therapy-Resistant Pediatric Brain Tumors. Mol Cancer Ther 2018; 17:1504-1514. [PMID: 29654065 DOI: 10.1158/1535-7163.mct-17-0792] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2017] [Revised: 01/03/2018] [Accepted: 03/15/2018] [Indexed: 11/16/2022]
Abstract
Brain tumors remain the leading cause of cancer-related deaths in children and often are associated with long-term sequelae among survivors of current therapies. Hence, there is an urgent need to identify actionable targets and to develop more effective therapies. Telomerase and telomeres play important roles in cancer, representing attractive therapeutic targets to treat children with poor-prognosis brain tumors such as diffuse intrinsic pontine glioma (DIPG), high-grade glioma (HGG), and high-risk medulloblastoma. We have previously shown that DIPG, HGG, and medulloblastoma frequently express telomerase activity. Here, we show that the telomerase-dependent incorporation of 6-thio-2'deoxyguanosine (6-thio-dG), a telomerase substrate precursor analogue, into telomeres leads to telomere dysfunction-induced foci (TIF) along with extensive genomic DNA damage, cell growth inhibition, and cell death of primary stem-like cells derived from patients with DIPG, HGG, and medulloblastoma. Importantly, the effect of 6-thio-dG is persistent even after drug withdrawal. Treatment with 6-thio-dG elicits a sequential activation of ATR and ATM pathways and induces G2-M arrest. In vivo treatment of mice bearing medulloblastoma xenografts with 6-thio-dG delays tumor growth and increases in-tumor TIFs and apoptosis. Furthermore, 6-thio-dG crosses the blood-brain barrier and specifically targets tumor cells in an orthotopic mouse model of DIPG. Together, our findings suggest that 6-thio-dG is a promising novel approach to treat therapy-resistant telomerase-positive pediatric brain tumors. Mol Cancer Ther; 17(7); 1504-14. ©2018 AACR.
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Affiliation(s)
- Satarupa Sengupta
- Brain Tumor Center, Division of Oncology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| | - Matthew Sobo
- Brain Tumor Center, Division of Oncology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| | - Kyungwoo Lee
- Brain Tumor Center, Division of Oncology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| | - Shiva Senthil Kumar
- Brain Tumor Center, Division of Oncology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| | - Angela R White
- Brain Tumor Center, Division of Oncology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| | - Ilgen Mender
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Christine Fuller
- Division of Pathology and Laboratory Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| | - Lionel M L Chow
- Brain Tumor Center, Division of Oncology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| | - Maryam Fouladi
- Brain Tumor Center, Division of Oncology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| | - Jerry W Shay
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Rachid Drissi
- Brain Tumor Center, Division of Oncology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio.
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26
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Ko E, Seo HW, Jung G. Telomere length and reactive oxygen species levels are positively associated with a high risk of mortality and recurrence in hepatocellular carcinoma. Hepatology 2018; 67:1378-1391. [PMID: 29059467 DOI: 10.1002/hep.29604] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Revised: 09/25/2017] [Accepted: 10/16/2017] [Indexed: 12/27/2022]
Abstract
UNLABELLED Telomeres protect chromosomal ends from deterioration and have been shown to be susceptible to shortening by reactive oxygen species (ROS)-induced damage. ROS levels increase during the progression from early to advanced hepatocellular carcinoma (HCC). An independent study found that the telomeres in most HCC tissues lengthened during carcinogenic advancement. Activated telomerase has been hypothesized to elongate telomeres during the progression of malignant HCC, but it remains unclear which signaling pathway is necessary for telomerase activation in HCC. Here, we showed using cell lines derived from human HCC that H2 O2 , which is a major component of ROS in living organisms, elongates telomeres by increasing telomerase activity through protein kinase B (AKT) activation. The AKT inhibitor, perifosine, decreased telomere length, cellular viability, and H2 O2 -mediated migration and invasion capacity in HCC cells while also inhibiting AKT activation, telomere maintenance, and tumor growth in nude mice. Advanced HCC tissues showed a positive correlation among ROS levels, phosphorylated AKT (pAKT) levels, and telomere length. Furthermore, patients with HCC tumors that have high ROS levels and long telomeres displayed poorer survival rates. These data demonstrate the significant utilities of ROS levels, pAKT levels, and telomere length for predicting a poor prognosis in patients with HCC. Taken together, AKT activation could be essential for telomere maintenance in advanced HCC tumors as well as being an important contributor to malignant HCC progression. CONCLUSION We showed that H2 O2 contributes to telomere elongation through AKT activation in advanced HCC, suggesting that an AKT inhibitor such as perifosine may be useful for treating patients with malignant HCC. (Hepatology 2018;67:1378-1391).
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Affiliation(s)
- Eunkyong Ko
- Department of Biological Sciences, College of Natural Sciences, Seoul National University, Seoul, South Korea
| | - Hyun-Wook Seo
- Department of Biological Sciences, College of Natural Sciences, Seoul National University, Seoul, South Korea
| | - Guhung Jung
- Department of Biological Sciences, College of Natural Sciences, Seoul National University, Seoul, South Korea
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27
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Frink RE, Peyton M, Schiller JH, Gazdar AF, Shay JW, Minna JD. Telomerase inhibitor imetelstat has preclinical activity across the spectrum of non-small cell lung cancer oncogenotypes in a telomere length dependent manner. Oncotarget 2017; 7:31639-51. [PMID: 27192120 PMCID: PMC5077965 DOI: 10.18632/oncotarget.9335] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Accepted: 04/27/2016] [Indexed: 11/25/2022] Open
Abstract
Telomerase was evaluated as a therapeutic oncotarget by studying the efficacy of the telomerase inhibitor imetelstat in non-small cell lung cancer (NSCLC) cell lines to determine the range of response phenotypes and identify potential biomarkers of response. A panel of 63 NSCLC cell lines was studied for telomere length and imetelstat efficacy in inhibiting colony formation and no correlation was found with patient characteristics, tumor histology, and oncogenotypes. While there was no overall correlation between imetelstat efficacy with initial telomere length (ranging from 1.5 to 20 kb), the quartile of NSCLC lines with the shortest telomeres was more sensitive than the quartile with the longest telomeres. Continuous long-term treatment with imetelstat resulted in sustained telomerase inhibition, progressive telomere shortening and eventual growth inhibition in a telomere-length dependent manner. Cessation of imetelstat therapy before growth inhibition was followed by telomere regrowth. Likewise, in vivo imetelstat treatment caused tumor xenograft growth inhibition in a telomere-length dependent manner. We conclude from these preclinical studies of telomerase as an oncotarget tested by imetelstat response that imetelstat has efficacy across the entire oncogenotype spectrum of NSCLC, continuous therapy is necessary to prevent telomere regrowth, and short telomeres appears to be the best treatment biomarker.
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Affiliation(s)
- Robin E Frink
- Hamon Center for Therapeutic Oncology Research, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Michael Peyton
- Hamon Center for Therapeutic Oncology Research, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Joan H Schiller
- Inova Schar Cancer Institute, Falls Church, VA, USA.,Simmons Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX, USA.,Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Adi F Gazdar
- Hamon Center for Therapeutic Oncology Research, University of Texas Southwestern Medical Center, Dallas, TX, USA.,Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX, USA.,Simmons Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Jerry W Shay
- Simmons Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX, USA.,Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX, USA.,Center for Excellence in Genomics Medicine Research, King Abdulaziz University, Jeddah, Saudi Arabia
| | - John D Minna
- Hamon Center for Therapeutic Oncology Research, University of Texas Southwestern Medical Center, Dallas, TX, USA.,Simmons Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX, USA.,Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX, USA.,Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
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28
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Inhibitors of telomerase and poly(ADP-ribose) polymerases synergize to limit the lifespan of pancreatic cancer cells. Oncotarget 2017; 8:83754-83767. [PMID: 29137380 PMCID: PMC5663552 DOI: 10.18632/oncotarget.19410] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Accepted: 07/12/2017] [Indexed: 01/05/2023] Open
Abstract
Imetelstat (GRN163L) is a potent and selective inhibitor of telomerase. We have previously reported that GRN163L could shorten telomeres and limit the lifespan of CD18/HPAF and CAPAN1 pancreatic cancer cells. Here, we examined the effects of GRN163L on two other pancreatic cancer cell lines: AsPC1 and L3.6pl. In both lines, chronic exposure to GRN163L led to an initial shortening of telomeres followed by a stabilization of extremely short telomeres. In AsPC1 cells, telomere attrition eventually led to the induction of crisis and the loss of the treated population. In L3.6pl cells, crisis was transient and followed by the emergence of GRN163L-resistant cells, which could grow at increasing concentrations of GRN163L. The Shelterin complex is a telomere-associated complex that limits the access of telomerase to telomeres. The telomerase inhibitory function of this complex can be enhanced by drugs that block the poly(ADP-ribosyl)ation of its TRF1 and/or TRF2 subunits. Combined treatment of the GRN163L-resistant L3.6pl cells with GRN163L and 3-aminobenzamide (3AB), a general inhibitor of poly(ADP-ribose) polymerases, led to additional telomere shortening and limited the lifespan of the resistant cells. Results from this work suggest that inhibitors of telomerase and poly(ADP-ribose) polymerases can cooperate to limit the lifespan of pancreatic cancer cells.
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29
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Berardinelli F, Coluzzi E, Sgura A, Antoccia A. Targeting telomerase and telomeres to enhance ionizing radiation effects in in vitro and in vivo cancer models. MUTATION RESEARCH-REVIEWS IN MUTATION RESEARCH 2017; 773:204-219. [PMID: 28927529 DOI: 10.1016/j.mrrev.2017.02.004] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Revised: 02/13/2017] [Accepted: 02/14/2017] [Indexed: 01/05/2023]
Abstract
One of the hallmarks of cancer consists in the ability of tumor cells to divide indefinitely, and to maintain stable telomere lengths throughout the activation of specific telomere maintenance mechanisms (TMM). Therefore in the last fifteen years, researchers proposed to target telomerase or telomeric structure in order to block limitless replicative potential of cancer cells providing a fascinating strategy for a broad-spectrum cancer therapy. In the present review, we report in vitro and in vivo evidence regarding the use of chemical agents targeting both telomerase or telomere structure and showing promising antitumor effects when used in combination with ionizing radiation (IR). RNA interference, antisense oligonucleotides (e.g., GRN163L), non-nucleoside inhibitors (e.g., BIBR1532) and nucleoside analogs (e.g., AZT) represent some of the most potent strategies to inhibit telomerase activity used in combination with IR. Furthermore, radiosensitizing effects were demonstrated also for agents acting directly on the telomeric structure such as G4-ligands (e.g., RHPS4 and Telomestatin) or telomeric-oligos (T-oligos). To date, some of these compounds are under clinical evaluation (e.g., GRN163L and KML001). Advantages of Telomere/Telomerase Targeting Compounds (T/TTCs) coupled with radiotherapy may be relevant in the treatment of radioresistant tumors and in the development of new optimized treatment plans with reduced dose adsorbed by patients and consequent attenuation of short- end long-term side effects. Pros and cons of possible future applications in cancer therapy based on the combination of T/TCCs and radiation treatment are discussed.
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Affiliation(s)
- F Berardinelli
- Dipartimento di Scienze, Università Roma Tre, Rome Italy; Istituto Nazionale di Fisica Nucleare, INFN, Sezione di Roma Tre, Rome, Italy.
| | - E Coluzzi
- Dipartimento di Scienze, Università Roma Tre, Rome Italy
| | - A Sgura
- Dipartimento di Scienze, Università Roma Tre, Rome Italy; Istituto Nazionale di Fisica Nucleare, INFN, Sezione di Roma Tre, Rome, Italy
| | - A Antoccia
- Dipartimento di Scienze, Università Roma Tre, Rome Italy; Istituto Nazionale di Fisica Nucleare, INFN, Sezione di Roma Tre, Rome, Italy
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30
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Waghorn PA, Jackson MR, Gouverneur V, Vallis KA. Targeting telomerase with radiolabeled inhibitors. Eur J Med Chem 2017; 125:117-129. [PMID: 27657809 PMCID: PMC5154340 DOI: 10.1016/j.ejmech.2016.09.028] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Revised: 09/08/2016] [Accepted: 09/09/2016] [Indexed: 12/22/2022]
Abstract
The expression of telomerase in approximately 85% of cancers and its absence in the majority of normal cells makes it an attractive target for cancer therapy. However the lag period between initiation of telomerase inhibition and growth arrest makes direct inhibition alone an insufficient method of treatment. However, telomerase inhibition has been shown to enhance cancer cell radiosensitivity. To investigate the strategy of simultaneously inhibiting telomerase while delivering targeted radionuclide therapy to cancer cells, 123I-radiolabeled inhibitors of telomerase were synthesized and their effects on cancer cell survival studied. An 123I-labeled analogue of the telomerase inhibitor MST-312 inhibited telomerase with an IC50 of 1.58 μM (MST-312 IC50: 0.23 μM). Clonogenic assays showed a dose dependant effect of 123I-MST-312 on cell survival in a telomerase positive cell line, MDA-MB-435.
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Affiliation(s)
- Philip A Waghorn
- CR-UK/MRC Oxford Institute for Radiation Oncology, University of Oxford, Old Road Campus Research Building, Off Roosevelt Drive, Oxford, OX3 7DQ, UK.
| | - Mark R Jackson
- CR-UK/MRC Oxford Institute for Radiation Oncology, University of Oxford, Old Road Campus Research Building, Off Roosevelt Drive, Oxford, OX3 7DQ, UK.
| | - Veronique Gouverneur
- Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford, OX1 3TA, UK.
| | - Katherine A Vallis
- CR-UK/MRC Oxford Institute for Radiation Oncology, University of Oxford, Old Road Campus Research Building, Off Roosevelt Drive, Oxford, OX3 7DQ, UK.
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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: 9.5] [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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Chen Y, Zhang Y. Functional and mechanistic analysis of telomerase: An antitumor drug target. Pharmacol Ther 2016; 163:24-47. [DOI: 10.1016/j.pharmthera.2016.03.017] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Accepted: 03/29/2016] [Indexed: 01/26/2023]
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Bell RJA, Rube HT, Xavier-Magalhães A, Costa BM, Mancini A, Song JS, Costello JF. Understanding TERT Promoter Mutations: A Common Path to Immortality. Mol Cancer Res 2016; 14:315-23. [PMID: 26941407 PMCID: PMC4852159 DOI: 10.1158/1541-7786.mcr-16-0003] [Citation(s) in RCA: 201] [Impact Index Per Article: 25.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Accepted: 02/24/2016] [Indexed: 12/23/2022]
Abstract
Telomerase (TERT) activation is a fundamental step in tumorigenesis. By maintaining telomere length, telomerase relieves a main barrier on cellular lifespan, enabling limitless proliferation driven by oncogenes. The recently discovered, highly recurrent mutations in the promoter of TERT are found in over 50 cancer types, and are the most common mutation in many cancers. Transcriptional activation of TERT, via promoter mutation or other mechanisms, is the rate-limiting step in production of active telomerase. Although TERT is expressed in stem cells, it is naturally silenced upon differentiation. Thus, the presence of TERT promoter mutations may shed light on whether a particular tumor arose from a stem cell or more differentiated cell type. It is becoming clear that TERT mutations occur early during cellular transformation, and activate the TERT promoter by recruiting transcription factors that do not normally regulate TERT gene expression. This review highlights the fundamental and widespread role of TERT promoter mutations in tumorigenesis, including recent progress on their mechanism of transcriptional activation. These somatic promoter mutations, along with germline variation in the TERT locus also appear to have significant value as biomarkers of patient outcome. Understanding the precise molecular mechanism of TERT activation by promoter mutation and germline variation may inspire novel cancer cell-specific targeted therapies for a large number of cancer patients.
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Affiliation(s)
- Robert J A Bell
- Department of Neurological Surgery, University of California, San Francisco, California
| | - H Tomas Rube
- Department of Biological Sciences, Columbia University, New York, New York
| | - Ana Xavier-Magalhães
- Department of Neurological Surgery, University of California, San Francisco, California. Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, Braga, Portugal. ICVS/3B's-PT Government Associate Laboratory, Braga/Guimarães, Braga, Portugal
| | - Bruno M Costa
- Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, Braga, Portugal. ICVS/3B's-PT Government Associate Laboratory, Braga/Guimarães, Braga, Portugal
| | - Andrew Mancini
- Department of Neurological Surgery, University of California, San Francisco, California
| | - Jun S Song
- Departments of Bioengineering and Physics, University of Illinois, Urbana-Champaign, Illinois
| | - Joseph F Costello
- Department of Neurological Surgery, University of California, San Francisco, California.
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Heeg S. Variations in telomere maintenance and the role of telomerase inhibition in gastrointestinal cancer. PHARMACOGENOMICS & PERSONALIZED MEDICINE 2015; 8:171-80. [PMID: 26675332 PMCID: PMC4675635 DOI: 10.2147/pgpm.s52808] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Immortalization is an important step toward the malignant transformation of human cells and is critically dependent upon telomere maintenance. There are two known mechanisms to maintain human telomeres. The process of telomere maintenance is either mediated through activation of the enzyme telomerase or through an alternative mechanism of telomere lengthening called ALT. While 85% of all human tumors show reactivation of telomerase, the remaining 15% are able to maintain telomeres via ALT. The therapeutic potential of telomerase inhibitors is currently investigated in a variety of human cancers. Gastrointestinal tumors are highly dependent on telomerase as a mechanism of telomere maintenance, rendering telomeres as well as telomerase potential targets for cancer therapy. This article focuses on the molecular mechanisms of telomere biology and telomerase activation in gastrointestinal cancers and reviews strategies of telomerase inhibition and their potential therapeutic use in these tumor entities.
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Affiliation(s)
- Steffen Heeg
- Department of Medicine II, Gastroenterology, Hepatology, Endocrinology, and Infectious Diseases, Medical Center - University of Freiburg, Freiburg, Germany
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Peterson DR, Mok HOL, Au DWT. Modulation of telomerase activity in fish muscle by biological and environmental factors. Comp Biochem Physiol C Toxicol Pharmacol 2015; 178:51-59. [PMID: 26400776 DOI: 10.1016/j.cbpc.2015.09.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Revised: 09/10/2015] [Accepted: 09/10/2015] [Indexed: 01/10/2023]
Abstract
Telomerase expression has long been linked to promotion of tumor growth and cell proliferation in mammals. Interestingly, telomerase activity (TA) has been detected in skeletal muscle for a variety of fish species. Despite this being a unique feature in fish, very few studies have investigated the potential role of TA in muscle. The present study was set to prove the concepts that muscle telomerase in fish is related to body growth, and more specifically, to muscle cell proliferation and apoptosis in vivo. Moreover, muscle TA can be influenced by biotic factors and modulated by environmental stress. Using three fish species, mangrove red snapper (Lutjanus argentimaculatus), orange-spotted grouper (Epinephelus coioides), and marine medaka (Oryzias melastigma), the present work reports for the first time that fish muscle TA was sensitive to the environmental stresses of starvation, foodborne exposure to benzo[a]pyrene, and hypoxia. In marine medaka, muscle TA was coupled with fish growth during early life stages. Upon sexual maturation, muscle TA was confounded by sex (female>male). Muscle TA was significantly correlated with telomerase reverse transcriptase (TERT) protein expression (Pearson correlation r=0.892; p≤0.05), which was coupled with proliferating cell nuclear antigen (PCNA) cell proliferation, but not associated with apoptosis (omBax/omBcl2 ratio) in muscle tissue. The results reported here have bridged the knowledge gap between the existence and function of telomerase in fish muscle. The underlying regulatory mechanisms of muscle TA in fish warrant further exploration for comparison with telomerase regulation in mammals.
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Affiliation(s)
- Drew Ryan Peterson
- State Key Laboratory in Marine Pollution, Department of Biology and Chemistry, City University of Hong Kong, Hong Kong SAR
| | - Helen Oi Lam Mok
- State Key Laboratory in Marine Pollution, Department of Biology and Chemistry, City University of Hong Kong, Hong Kong SAR
| | - Doris Wai Ting Au
- State Key Laboratory in Marine Pollution, Department of Biology and Chemistry, City University of Hong Kong, Hong Kong SAR; Shenzhen Key Laboratory for the Sustainable Use of Marine Biodiversity, Research Centre for the Oceans and Human Health, City University of Hong Kong, Shenzhen Research Institute, Shenzhen 518057, China.
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Yaswen P, MacKenzie KL, Keith WN, Hentosh P, Rodier F, Zhu J, Firestone GL, Matheu A, Carnero A, Bilsland A, Sundin T, Honoki K, Fujii H, Georgakilas AG, Amedei A, Amin A, Helferich B, Boosani CS, Guha G, Ciriolo MR, Chen S, Mohammed SI, Azmi AS, Bhakta D, Halicka D, Niccolai E, Aquilano K, Ashraf SS, Nowsheen S, Yang X. Therapeutic targeting of replicative immortality. Semin Cancer Biol 2015; 35 Suppl:S104-S128. [PMID: 25869441 PMCID: PMC4600408 DOI: 10.1016/j.semcancer.2015.03.007] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2014] [Revised: 03/06/2015] [Accepted: 03/13/2015] [Indexed: 12/15/2022]
Abstract
One of the hallmarks of malignant cell populations is the ability to undergo continuous proliferation. This property allows clonal lineages to acquire sequential aberrations that can fuel increasingly autonomous growth, invasiveness, and therapeutic resistance. Innate cellular mechanisms have evolved to regulate replicative potential as a hedge against malignant progression. When activated in the absence of normal terminal differentiation cues, these mechanisms can result in a state of persistent cytostasis. This state, termed “senescence,” can be triggered by intrinsic cellular processes such as telomere dysfunction and oncogene expression, and by exogenous factors such as DNA damaging agents or oxidative environments. Despite differences in upstream signaling, senescence often involves convergent interdependent activation of tumor suppressors p53 and p16/pRB, but can be induced, albeit with reduced sensitivity, when these suppressors are compromised. Doses of conventional genotoxic drugs required to achieve cancer cell senescence are often much lower than doses required to achieve outright cell death. Additional therapies, such as those targeting cyclin dependent kinases or components of the PI3K signaling pathway, may induce senescence specifically in cancer cells by circumventing defects in tumor suppressor pathways or exploiting cancer cells’ heightened requirements for telomerase. Such treatments sufficient to induce cancer cell senescence could provide increased patient survival with fewer and less severe side effects than conventional cytotoxic regimens. This positive aspect is countered by important caveats regarding senescence reversibility, genomic instability, and paracrine effects that may increase heterogeneity and adaptive resistance of surviving cancer cells. Nevertheless, agents that effectively disrupt replicative immortality will likely be valuable components of new combinatorial approaches to cancer therapy.
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Affiliation(s)
- Paul Yaswen
- Life Sciences Division, Lawrence Berkeley National Lab, Berkeley, CA, United States.
| | - Karen L MacKenzie
- Children's Cancer Institute Australia, Kensington, New South Wales, Australia.
| | | | | | | | - Jiyue Zhu
- Washington State University College of Pharmacy, Pullman, WA, United States.
| | | | | | - Amancio Carnero
- Instituto de Biomedicina de Sevilla, HUVR, Consejo Superior de Investigaciones Cientificas, Universdad de Sevilla, Seville, Spain.
| | | | | | | | | | | | | | - Amr Amin
- United Arab Emirates University, Al Ain, United Arab Emirates; Cairo University, Cairo, Egypt
| | - Bill Helferich
- University of Illinois at Urbana Champaign, Champaign, IL, United States
| | | | - Gunjan Guha
- SASTRA University, Thanjavur, Tamil Nadu, India
| | | | - Sophie Chen
- Ovarian and Prostate Cancer Research Trust, Guildford, Surrey, United Kingdom
| | | | - Asfar S Azmi
- Karmanos Cancer Institute, Wayne State University, Detroit, MI, United States
| | | | | | | | | | - S Salman Ashraf
- United Arab Emirates University, Al Ain, United Arab Emirates; Cairo University, Cairo, Egypt
| | | | - Xujuan Yang
- University of Illinois at Urbana Champaign, Champaign, IL, United States
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Sunami Y, von Figura G, Kleger A, Strnad P, Hüser N, Hartmann D. The role of telomeres in liver disease. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2015; 125:159-72. [PMID: 24993702 DOI: 10.1016/b978-0-12-397898-1.00007-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Telomeres stabilize open chromosome ends and protect them against chromosomal end-to-end fusions, breakage, instability, and nonreciprocal translocations. Telomere dysfunction is known to lead to an impaired regenerative capacity of hepatocytes and an increased cirrhosis formation in the context of acute and chronic liver injury. In addition, telomere dysfunction and telomerase mutations have been associated with the induction of chromosomal instability and consequently with cirrhosis development and hepatocarcinogenesis. The identification of molecular mechanisms related to telomere dysfunction and telomerase activation might lead to new therapeutic strategies. In this chapter, we are reviewing the current knowledge about the importance of telomere dysfunction in liver diseases.
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Affiliation(s)
- Yoshiaki Sunami
- Department of General Surgery, Klinikum rechts der Isar, Technical University Munich, Munich, Germany
| | - Guido von Figura
- Department of Internal Medicine II, Klinikum rechts der Isar, Technical University Munich, Munich, Germany
| | - Alexander Kleger
- Department of Internal Medicine I, Ulm University Hospital, Ulm, Germany
| | - Pavel Strnad
- Department of Internal Medicine III and IZKF, University Hospital Aachen, Aachen, Germany
| | - Norbert Hüser
- Department of General Surgery, Klinikum rechts der Isar, Technical University Munich, Munich, Germany
| | - Daniel Hartmann
- Department of General Surgery, Klinikum rechts der Isar, Technical University Munich, Munich, Germany
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The telomerase inhibitor imetelstat alone, and in combination with trastuzumab, decreases the cancer stem cell population and self-renewal of HER2+ breast cancer cells. Breast Cancer Res Treat 2015; 149:607-18. [PMID: 25627551 DOI: 10.1007/s10549-015-3270-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2014] [Accepted: 01/04/2015] [Indexed: 12/28/2022]
Abstract
Cancer stem cells (CSCs) are thought to be responsible for tumor progression, metastasis, and recurrence. HER2 overexpression is associated with increased CSCs, which may explain the aggressive phenotype and increased likelihood of recurrence for HER2(+) breast cancers. Telomerase is reactivated in tumor cells, including CSCs, but has limited activity in normal tissues, providing potential for telomerase inhibition in anti-cancer therapy. The purpose of this study was to investigate the effects of a telomerase antagonistic oligonucleotide, imetelstat (GRN163L), on CSC and non-CSC populations of HER2(+) breast cancer cell lines. The effects of imetelstat on CSC populations of HER2(+) breast cancer cells were measured by ALDH activity and CD44/24 expression by flow cytometry as well as mammosphere assays for functionality. Combination studies in vitro and in vivo were utilized to test for synergism between imetelstat and trastuzumab. Imetelstat inhibited telomerase activity in both subpopulations. Moreover, imetelstat alone and in combination with trastuzumab reduced the CSC fraction and inhibited CSC functional ability, as shown by decreased mammosphere counts and invasive potential. Tumor growth rate was slower in combination-treated mice compared to either drug alone. Additionally, there was a trend toward decreased CSC marker expression in imetelstat-treated xenograft cells compared to vehicle control. Furthermore, the observed decrease in CSC marker expression occurred prior to and after telomere shortening, suggesting that imetelstat acts on the CSC subpopulation in telomere length-dependent and -independent mechanisms. Our study suggests addition of imetelstat to trastuzumab may enhance the effects of HER2 inhibition therapy, especially in the CSC population.
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Abstract
Telomeres form protective caps at the ends of linear chromosomes to prevent nucleolytic degradation, end-to-end fusion, irregular recombination, and chromosomal instability. Telomeres are composed of repetitive DNA sequences (TTAGGG)n in humans, that are bound by specialized telomere binding proteins. Telomeres lose capping function in response to telomere shortening, which occurs during each division of cells that lack telomerase activity-the enzyme that can synthesize telomeres de novo. Telomeres have a dual role in cancer: telomere shortening can lead to induction of chromosomal instability and to the initiation of tumors, however, initiated tumors need to reactivate telomerase in order to stabilize chromosomes and to gain immortal growth capacity. In this review, we summarize current knowledge on the role of telomeres in the maintenance of chromosomal stability and carcinogenesis.
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Mender I, Gryaznov S, Dikmen ZG, Wright WE, Shay JW. Induction of telomere dysfunction mediated by the telomerase substrate precursor 6-thio-2'-deoxyguanosine. Cancer Discov 2014; 5:82-95. [PMID: 25516420 DOI: 10.1158/2159-8290.cd-14-0609] [Citation(s) in RCA: 104] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
UNLABELLED The relationships between telomerase and telomeres represent attractive targets for new anticancer agents. Here, we report that the nucleoside analogue 6-thio-2'-deoxyguanosine (6-thio-dG) is recognized by telomerase and is incorporated into de novo-synthesized telomeres. This results in modified telomeres, leading to telomere dysfunction, but only in cells expressing telomerase. 6-Thio-dG, but not 6-thioguanine, induced telomere dysfunction in telomerase-positive human cancer cells and hTERT-expressing human fibroblasts, but not in telomerase-negative cells. Treatment with 6-thio-dG resulted in rapid cell death for the vast majority of the cancer cell lines tested, whereas normal human fibroblasts and human colonic epithelial cells were largely unaffected. In A549 lung cancer cell-based mouse xenograft studies, 6-thio-dG caused a decrease in the tumor growth rate superior to that observed with 6-thioguanine treatment. In addition, 6-thio-dG increased telomere dysfunction in tumor cells in vivo. These results indicate that 6-thio-dG may provide a new telomere-addressed telomerase-dependent anticancer approach. SIGNIFICANCE Telomerase is an almost universal oncology target, yet there are few telomerase-directed therapies in human clinical trials. In the present study, we demonstrate a small-molecule telomerase substrate approach that induces telomerase-mediated targeted "telomere uncapping," but only in telomerase-positive cancer cells, with minimal effects in normal telomerase-negative cells.
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Affiliation(s)
- Ilgen Mender
- Department of Cell Biology, The University of Texas Southwestern Medical Center, Dallas, Texas. Faculty of Medicine, Department of Biochemistry, Hacettepe University, Ankara, Turkey
| | | | - Z Gunnur Dikmen
- Faculty of Medicine, Department of Biochemistry, Hacettepe University, Ankara, Turkey
| | - Woodring E Wright
- Department of Cell Biology, The University of Texas Southwestern Medical Center, Dallas, Texas
| | - Jerry W Shay
- Department of Cell Biology, The University of Texas Southwestern Medical Center, Dallas, Texas. Center for Excellence in Genomics Medicine Research, King Abdulaziz University, Jeddah, Saudi Arabia.
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Picariello L, Grappone C, Polvani S, Galli A. Telomerase activity: An attractive target for cancer therapeutics. World J Pharmacol 2014; 3:86-96. [DOI: 10.5497/wjp.v3.i4.86] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Revised: 10/01/2014] [Accepted: 10/29/2014] [Indexed: 02/06/2023] Open
Abstract
Telomeres are non-coding tandem repeats of 1000-2000 TTAGGG nucleotide DNA sequences on the 3’ termini of human chromosomes where they serve as protective “caps” from degradation and loss of genes. The “cap” at the end of chromosome required to protect its integrity is a 150-200 nucleotide-long single stranded G-rich 3’ overhang that forms two higher order structures, a T-loop with Sheltering complex, or a G-quadruplex complex. Telomerase is a human ribonucleoprotein reverse transcriptase that continually added single stranded TTAGGG DNA sequences onto the single strand 3’ of telomere in the 5’ to 3’ direction. Telomerase activity is detected in male germ line cells, proliferative cells of renewal tissues, some adult pluripotent stem cells, embryonic cells, but in most somatic cells is not detected. Re-expression or up-regulation of telomerase in tumours cells is considered as a critical step in cell tumorigenesis and telomerase is widely considered as a tumour marker and a target for anticancer drugs. Different approaches have been used in anticancer therapeutics targeting telomerase. Telomerase inhibitors can block directly Human TElomerase Reverse Transcriptase (hTERT) or Human TElomerase RNA telomerase subunits activity, or G-quadruplex and Sheltering complex components, shortening telomeres and inhibiting cell proliferation. Telomerase can become an immune target and GV1001, Vx-001, I540 are the most widespread vaccines used with encouraging results. Another method is to use hTERT promoter to drive suicide gene expression or to control a lytic virus replication. Recently telomerase activity was used to activate pro-drugs such as Acycloguanosyl 5’-thymidyltriphosphate, a synthetic ACV-derived molecule when it is activated by telomerase it does not require any virus or host active immune response to induce suicide gene therapy. Advantage of all these therapies is that target only neoplastic cells without any effects in normal cells, avoiding toxicity and adverse effects of the current chemotherapy. However, as not all the approaches are equally efficient, further studies will be necessary.
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Fairlie J, Harrington L. Enforced telomere elongation increases the sensitivity of human tumour cells to ionizing radiation. DNA Repair (Amst) 2014; 25:54-9. [PMID: 25484304 PMCID: PMC4286114 DOI: 10.1016/j.dnarep.2014.11.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2014] [Revised: 11/13/2014] [Accepted: 11/17/2014] [Indexed: 10/29/2022]
Abstract
More than 85% of all human cancers possess the ability to maintain chromosome ends, or telomeres, by virtue of telomerase activity. Loss of functional telomeres is incompatible with survival, and telomerase inhibition has been established in several model systems to be a tractable target for cancer therapy. As human tumour cells typically maintain short equilibrium telomere lengths, we wondered if enforced telomere elongation would positively or negatively impact cell survival. We found that telomere elongation beyond a certain length significantly decreased cell clonogenic survival after gamma irradiation. Susceptibility to irradiation was dosage-dependent and increased at telomere lengths exceeding 17kbp despite the fact that all chromosome ends retained telomeric DNA. These data suggest that an optimal telomere length may promote human cancer cell survival in the presence of genotoxic stress.
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Affiliation(s)
- Jennifer Fairlie
- Wellcome Trust Centre for Cell Biology and Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Mayfield Road, EH9 3JR Edinburgh, UK
| | - Lea Harrington
- Wellcome Trust Centre for Cell Biology and Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Mayfield Road, EH9 3JR Edinburgh, UK; Institute for Research in Immunology and Cancer, Department of Medicine, University of Montreal, 2950 chemin de Polytechnique, Montreal, Canada H3T 1J4.
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The inhibitory effect of helenalin on telomerase activity is attributed to the alkylation of the CYS445 residue: Evidence from QM/MM simulations. J Mol Graph Model 2014; 51:97-103. [DOI: 10.1016/j.jmgm.2014.04.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Revised: 03/16/2014] [Accepted: 04/28/2014] [Indexed: 01/18/2023]
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Development of anticancer drugs based on the hallmarks of tumor cells. Tumour Biol 2014; 35:3981-95. [DOI: 10.1007/s13277-014-1649-y] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2013] [Accepted: 01/12/2014] [Indexed: 12/19/2022] Open
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Telomerase inhibitor Imetelstat (GRN163L) limits the lifespan of human pancreatic cancer cells. PLoS One 2014; 9:e85155. [PMID: 24409321 PMCID: PMC3883701 DOI: 10.1371/journal.pone.0085155] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2013] [Accepted: 11/23/2013] [Indexed: 12/25/2022] Open
Abstract
Telomerase is required for the unlimited lifespan of cancer cells. The vast majority of pancreatic adenocarcinomas overexpress telomerase activity and blocking telomerase could limit their lifespan. GRN163L (Imetelstat) is a lipid-conjugated N3'→P5' thio-phosphoramidate oligonucleotide that blocks the template region of telomerase. The aim of this study was to define the effects of long-term GRN163L exposure on the maintenance of telomeres and lifespan of pancreatic cancer cells. Telomere size, telomerase activity, and telomerase inhibition response to GRN163L were measured in a panel of 10 pancreatic cancer cell lines. The cell lines exhibited large differences in levels of telomerase activity (46-fold variation), but most lines had very short telomeres (2-3 kb in size). GRN163L inhibited telomerase in all 10 pancreatic cancer cell lines, with IC50 ranging from 50 nM to 200 nM. Continuous GRN163L exposure of CAPAN1 (IC50 = 75 nM) and CD18 cells (IC50 = 204 nM) resulted in an initial rapid shortening of the telomeres followed by the maintenance of extremely short but stable telomeres. Continuous exposure to the drug eventually led to crisis and to a complete loss of viability after 47 (CAPAN1) and 69 (CD18) doublings. Crisis In these cells was accompanied by activation of a DNA damage response (γ-H2AX) and evidence of both senescence (SA-β-galactosidase activity) and apoptosis (sub-G1 DNA content, PARP cleavage). Removal of the drug after long-term GRN163L exposure led to a reactivation of telomerase and re-elongation of telomeres in the third week of cultivation without GRN163L. These findings show that the lifespan of pancreatic cancer cells can be limited by continuous telomerase inhibition. These results should facilitate the design of future clinical trials of GRN163L in patients with pancreatic cancer.
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Telomerase: target for cancer treatment. Mol Oncol 2013. [DOI: 10.1017/cbo9781139046947.038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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Sekaran V, Soares J, Jarstfer MB. Telomere Maintenance as a Target for Drug Discovery. J Med Chem 2013; 57:521-38. [DOI: 10.1021/jm400528t] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Vijay Sekaran
- Division of Chemical Biology
and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Joana Soares
- Division of Chemical Biology
and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Michael B. Jarstfer
- Division of Chemical Biology
and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
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48
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Hepatocellular carcinoma and other malignancies in autoimmune hepatitis. Dig Dis Sci 2013; 58:1459-76. [PMID: 23306849 DOI: 10.1007/s10620-012-2525-5] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2012] [Accepted: 12/03/2012] [Indexed: 12/13/2022]
Abstract
Hepatocellular carcinoma and extrahepatic malignancies can complicate the course of autoimmune hepatitis, and these occurrences may increase in frequency as the survival of patients with cirrhosis is extended and the prospect of new nonstandard immune-modifying intervention is realized. The frequency of hepatocellular carcinoma in patients with autoimmune hepatitis and cirrhosis is 1-9 %, and annual occurrence in patients with cirrhosis is 1.1-1.9 %. The standardized incidence ratio for hepatocellular carcinoma in autoimmune hepatitis is 23.3 (95 % confidence interval (CI) 7.5-54.3) in Sweden, and the standardized mortality ratio for hepatobiliary cancer is 42.3 (95 % CI 20.3-77.9) in New Zealand. The principal risk factor is long-standing cirrhosis, and patients at risk are characterized mainly by cirrhosis for ≥ 10 years, manifestations of portal hypertension, persistent liver inflammation, and immunosuppressive therapy for ≥ 3 years. Multiple molecular disturbances, including the accumulation of senescent hepatocytes because of telomere shortening, step-wise accumulation of chromosomal injuries, and aberrations in transcription factors and genes, may contribute to the risk. Extraheptic malignancies of diverse cell types occur in 5 % in an unpredictable fashion. The standardized incidence ratio is 2.7 (95 % CI 1.8-3.9) in New Zealand, and non-melanoma skin cancers are most common. Outcomes are related to the nature and stage of the tumor at diagnosis. Surveillance recommendations have not been promulgated, but hepatic ultrasonography every six months in patients with cirrhosis is a consideration. Routine health screening measures for other malignancies should be applied diligently.
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Lee J, Sammond DW, Fiorini Z, Saludes JP, Resch MG, Hao B, Wang W, Yin H, Liu X. Computationally designed peptide inhibitors of the ubiquitin E3 ligase SCF(Fbx4). Chembiochem 2013; 14:445-51. [PMID: 23401343 DOI: 10.1002/cbic.201200777] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2012] [Indexed: 11/07/2022]
Abstract
A structure-based computational approach was used to rationally design peptide inhibitors that can target an E3 ligase (SCF(Fbx4) )-substrate (TRF1) interface and subsequent ubiquitylation. Characterization of the inhibitors demonstrates that our sequence-optimization protocol results in an increase in peptide-TRF1 affinity without compromising peptide-protein specificity.
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Affiliation(s)
- Junglim Lee
- Department of Chemistry and Biochemistry, 596 UCB, University of Colorado, JSCBB 3415 Colorado Avenue, Boulder, CO 80309-0215, USA
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Ruden M, Puri N. Novel anticancer therapeutics targeting telomerase. Cancer Treat Rev 2012; 39:444-56. [PMID: 22841437 DOI: 10.1016/j.ctrv.2012.06.007] [Citation(s) in RCA: 222] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2012] [Revised: 06/14/2012] [Accepted: 06/19/2012] [Indexed: 12/12/2022]
Abstract
Telomeres are protective caps at the ends of human chromosomes. Telomeres shorten with each successive cell division in normal human cells whereas, in tumors, they are continuously elongated by human telomerase reverse transcriptase (hTERT). Telomerase is overexpressed in 80-95% of cancers and is present in very low levels or is almost undetectable in normal cells. Because telomerase plays a pivotal role in cancer cell growth it may serve as an ideal target for anticancer therapeutics. Inhibition of telomerase may lead to a decrease of telomere length resulting in cell senescence and apoptosis in telomerase positive tumors. Several strategies of telomerase inhibition are reviewed, including small molecule inhibitors, antisense oligonucleotides, immunotherapies and gene therapies, targeting the hTERT or the ribonucleoprotein subunit hTER. G-quadruplex stabilizers, tankyrase and HSP90 inhibitors targeting telomere and telomerase assembly, and T-oligo approach are also covered. Based on this review, the most promising current telomerase targeting therapeutics are the antisense oligonucleotide inhibitor GRN163L and immunotherapies that use dendritic cells (GRVAC1), hTERT peptide (GV1001) or cryptic peptides (Vx-001). Most of these agents have entered phase I and II clinical trials in patients with various tumors, and have shown good response rates as evidenced by a reduction in tumor cell growth, increased overall disease survival, disease stabilization in advanced staged tumors and complete/partial responses. Most therapeutics have shown to be more effective when used in combination with standard therapies, resulting in concomitant telomere shortening and tumor mass shrinkage, as well as preventing tumor relapse and resistance to single agent therapy.
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Affiliation(s)
- Maria Ruden
- Department of Biomedical Sciences, University of Illinois College of Medicine at Rockford, Rockford, IL 61107-1822, USA
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