1
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Bajaj S, Kumar MS, Peters GJ, Mayur YC. Targeting telomerase for its advent in cancer therapeutics. Med Res Rev 2020; 40:1871-1919. [PMID: 32391613 DOI: 10.1002/med.21674] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2019] [Revised: 04/19/2020] [Accepted: 04/21/2020] [Indexed: 12/24/2022]
Abstract
Telomerase has emerged as an important primary target in anticancer therapy. It is a distinctive reverse transcriptase enzyme, which extends the length of telomere at the 3' chromosomal end, and uses telomerase reverse transcriptase (TERT) and telomerase RNA template-containing domains. Telomerase has a vital role and is a contributing factor in human health, mainly affecting cell aging and cell proliferation. Due to its unique feature, it ensures unrestricted cell proliferation in malignancy and plays a major role in cancer disease. The development of telomerase inhibitors with increased specificity and better pharmacokinetics is being considered to design and develop newer potent anticancer agents. Use of natural and synthetic compounds for the inhibition of telomerase activity can lead to an opening of new vistas in cancer treatment. This review details about the telomerase biochemistry, use of natural and synthetic compounds; vaccines and oncolytic virus in therapy that suppress the telomerase activity. We have discussed structure-activity relationships of various natural and synthetic telomerase inhibitors to help medicinal chemists and chemical biology researchers with a ready reference and updated status of their clinical trials. Suppression of human TERT (hTERT) activity through inhibition of hTERT promoter is an important approach for telomerase inhibition.
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Affiliation(s)
| | | | - G J Peters
- Department of Medical Oncology, VU University Medical Centre, Amsterdam, The Netherlands
| | - Y C Mayur
- SPPSPTM, SVKM's NMIMS, Mumbai, India
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2
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Liu P, Lu Z, Wu Y, Shang D, Zhao Z, Shen Y, Zhang Y, Zhu F, Liu H, Tu Z. Cellular Senescence-Inducing Small Molecules for Cancer Treatment. Curr Cancer Drug Targets 2020; 19:109-119. [PMID: 29848278 DOI: 10.2174/1568009618666180530092825] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 02/10/2018] [Accepted: 03/07/2018] [Indexed: 01/22/2023]
Abstract
Recently, the chemotherapeutic drug-induced cellular senescence has been considered a promising anti-cancer approach. The drug-induced senescence, which shows both similar and different hallmarks from replicative and oncogene-induced senescence, was regarded as a key determinant of tumor response to chemotherapy in vitro and in vivo. To date, an amount of effective chemotherapeutic drugs that can evoke senescence in cancer cells have been reported. The targets of these drugs differ substantially, including senescence signaling pathways, DNA replication process, DNA damage pathways, epigenetic modifications, microtubule polymerization, senescence-associated secretory phenotype (SASP), and so on. By summarizing senescence-inducing small molecule drugs together with their specific traits and corresponding mechanisms, this review is devoted to inform scientists to develop novel therapeutic strategies against cancer through inducing senescence.
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Affiliation(s)
- Peng Liu
- Institute of Life Sciences, Jiangsu University, Zhenjiang, Jiangsu 212013, China
| | - Ziwen Lu
- School of Pharmacy, Jiangsu University, Zhenjiang, Jiangsu 212013, China
| | - Yanfang Wu
- Institute of Life Sciences, Jiangsu University, Zhenjiang, Jiangsu 212013, China
| | - Dongsheng Shang
- Institute of Life Sciences, Jiangsu University, Zhenjiang, Jiangsu 212013, China.,School of Pharmacy, Jiangsu University, Zhenjiang, Jiangsu 212013, China
| | - Zhicong Zhao
- School of Pharmacy, Jiangsu University, Zhenjiang, Jiangsu 212013, China
| | - Yanting Shen
- School of Pharmacy, Jiangsu University, Zhenjiang, Jiangsu 212013, China
| | - Yafei Zhang
- School of Pharmacy, Jiangsu University, Zhenjiang, Jiangsu 212013, China
| | - Feifei Zhu
- Institute of Life Sciences, Jiangsu University, Zhenjiang, Jiangsu 212013, China
| | - Hanqing Liu
- School of Pharmacy, Jiangsu University, Zhenjiang, Jiangsu 212013, China
| | - Zhigang Tu
- Institute of Life Sciences, Jiangsu University, Zhenjiang, Jiangsu 212013, China
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3
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Structural Features of Nucleoprotein CST/Shelterin Complex Involved in the Telomere Maintenance and Its Association with Disease Mutations. Cells 2020; 9:cells9020359. [PMID: 32033110 PMCID: PMC7072152 DOI: 10.3390/cells9020359] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Revised: 01/23/2020] [Accepted: 01/24/2020] [Indexed: 12/29/2022] Open
Abstract
Telomere comprises the ends of eukaryotic linear chromosomes and is composed of G-rich (TTAGGG) tandem repeats which play an important role in maintaining genome stability, premature aging and onsets of many diseases. Majority of the telomere are replicated by conventional DNA replication, and only the last bit of the lagging strand is synthesized by telomerase (a reverse transcriptase). In addition to replication, telomere maintenance is principally carried out by two key complexes known as shelterin (TRF1, TRF2, TIN2, RAP1, POT1, and TPP1) and CST (CDC13/CTC1, STN1, and TEN1). Shelterin protects the telomere from DNA damage response (DDR) and regulates telomere length by telomerase; while, CST govern the extension of telomere by telomerase and C strand fill-in synthesis. We have investigated both structural and biochemical features of shelterin and CST complexes to get a clear understanding of their importance in the telomere maintenance. Further, we have analyzed ~115 clinically important mutations in both of the complexes. Association of such mutations with specific cellular fault unveils the importance of shelterin and CST complexes in the maintenance of genome stability. A possibility of targeting shelterin and CST by small molecule inhibitors is further investigated towards the therapeutic management of associated diseases. Overall, this review provides a possible direction to understand the mechanisms of telomere borne diseases, and their therapeutic intervention.
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4
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Chen X, Tang WJ, Shi JB, Liu MM, Liu XH. Therapeutic strategies for targeting telomerase in cancer. Med Res Rev 2019; 40:532-585. [PMID: 31361345 DOI: 10.1002/med.21626] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Revised: 07/12/2019] [Accepted: 07/16/2019] [Indexed: 12/13/2022]
Abstract
Telomere and telomerase play important roles in abnormal cell proliferation, metastasis, stem cell maintenance, and immortalization in various cancers. Therefore, designing of drugs targeting telomerase and telomere is of great significance. Over the past two decades, considerable knowledge regarding telomere and telomerase has been accumulated, which provides theoretical support for the design of therapeutic strategies such as telomere elongation. Therefore, the development of telomere-based therapies such as nucleoside analogs, non-nucleoside small molecules, antisense technology, ribozymes, and dominant negative human telomerase reverse transcriptase are being prioritized for eradicating a majority of tumors. While the benefits of telomere-based therapies are obvious, there is a need to address the limitations of various therapeutic strategies to improve the possibility of clinical applications. In this study, current knowledge of telomere and telomerase is discussed, and therapeutic strategies based on recent research are reviewed.
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Affiliation(s)
- Xing Chen
- School of Pharmacy, Anhui Province Key Laboratory of Major Autoimmune Diseases, Anhui Medical University, Hefei, People's Republic of China
| | - Wen-Jian Tang
- School of Pharmacy, Anhui Province Key Laboratory of Major Autoimmune Diseases, Anhui Medical University, Hefei, People's Republic of China
| | - Jing Bo Shi
- School of Pharmacy, Anhui Province Key Laboratory of Major Autoimmune Diseases, Anhui Medical University, Hefei, People's Republic of China
| | - Ming Ming Liu
- School of Pharmacy, Anhui Province Key Laboratory of Major Autoimmune Diseases, Anhui Medical University, Hefei, People's Republic of China
| | - Xin-Hua Liu
- School of Pharmacy, Anhui Province Key Laboratory of Major Autoimmune Diseases, Anhui Medical University, Hefei, People's Republic of China
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5
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Chen J, Wei Y, Chen X, Jiao J, Zhang Y. Polyunsaturated fatty acids ameliorate aging via redox-telomere-antioncogene axis. Oncotarget 2018; 8:7301-7314. [PMID: 28038469 PMCID: PMC5352322 DOI: 10.18632/oncotarget.14236] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Accepted: 12/20/2016] [Indexed: 12/02/2022] Open
Abstract
Polyunsaturated fatty acids (PUFA), a group of nourishing and health-promoting nutrients, ameliorate age-related chronic diseases. However, how PUFA especially n-3 PUFA exert anti-aging functions remains poorly understood. Here we link fish oil, docosahexaenoic acid (DHA) and arachidonic acid (AA) to the aging etiology via a redox-telomere-antioncogene axis based on D-galactose-induced aging mice. Both fish oil and PUFA enhanced hepatic superoxide dismutase (SOD) and catalase activities and cardiac SOD activities within the range of 18%-46%, 26%-65% and 19%-58%, respectively, whereas reduced cerebral monoamine oxidase activity, plasma F2-isoprostane level and cerebral lipid peroxidation level by 56%-90%, 20%-79% and 16%-54%, respectively. Thus, PUFA improve the in vivo redox and oxidative stress induced aging process, which however does not exhibit a dose-dependent manner. Notably, both PUFA and fish oil effectively inactivated testicular telomerase and inhibited c-Myc-mediated telomerase reverse transcriptase expression, whereas n-3 PUFA rather than n-6 PUFA protected liver and testes against telomere shortening within the range of 13%-25% and 25%-27%, respectively. Therefore, n-3 PUFA may be better at inhibiting the DNA damage induced aging process. Surprisingly, only DHA significantly suppressed cellular senescence pathway evidenced by testicular antioncogene p16 and p53 expression. This work provides evident support for the crosstalk between PUFA especially n-3 PUFA and the aging process via maintaining the in vivo redox homeostasis, rescuing age-related telomere attrition and down-regulating the antioncogene expression.
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Affiliation(s)
- Jingnan Chen
- Department of Food Science and Nutrition, College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou, Zhejiang, China
| | - Yan Wei
- Department of Food Science and Nutrition, College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou, Zhejiang, China
| | - Xinyu Chen
- Department of Food Science and Nutrition, College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou, Zhejiang, China
| | - Jingjing Jiao
- Department of Nutrition, School of Public Health, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Yu Zhang
- Department of Food Science and Nutrition, College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou, Zhejiang, China
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6
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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: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [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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7
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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: 5.8] [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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8
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Glukhov AI, Svinareva LV, Severin SE, Shvets VI. Telomerase inhibitors as novel antitumor drugs. APPL BIOCHEM MICRO+ 2011. [DOI: 10.1134/s0003683811070039] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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9
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Guittat L, Alberti P, Gomez D, De Cian A, Pennarun G, Lemarteleur T, Belmokhtar C, Paterski R, Morjani H, Trentesaux C, Mandine E, Boussin F, Mailliet P, Lacroix L, Riou JF, Mergny JL. Targeting human telomerase for cancer therapeutics. Cytotechnology 2011; 45:75-90. [PMID: 19003245 DOI: 10.1007/s10616-004-5127-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2004] [Accepted: 09/21/2004] [Indexed: 01/28/2023] Open
Abstract
The enzyme telomerase is involved in the replication of telomeres, specialized structures that cap and protect the ends of chromosomes. Its activity is required for maintenance of telomeres and for unlimited lifespan, a hallmark of cancer cells. Telomerase is overexpressed in the vast majority of human cancer cells and therefore represents an attractive target for therapy. Several approaches have been developed to inhibit this enzyme through the targeting of its RNA or catalytic components as well as its DNA substrate, the single-stranded 3'-telomeric overhang. Telomerase inhibitors are chemically diverse and include modified oligonucleotides as well as small diffusable molecules, both natural and synthetic. This review presents an update of recent investigations pertaining to these agents and discusses their biological properties in the context of the initial paradigm that the exposure of cancer cells to these agents should lead to progressive telomere shortening followed by a delayed growth arrest response.
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Affiliation(s)
- Lionel Guittat
- Laboratoire de Biophysique, Muséum National d'Histoire Naturelle USM503, INSERM U 565, CNRS UMR 5153, 43, rue Cuvier, 75231, Paris cedex 05, France
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10
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Xu Y. Chemistry in human telomere biology: structure, function and targeting of telomere DNA/RNA. Chem Soc Rev 2011; 40:2719-40. [DOI: 10.1039/c0cs00134a] [Citation(s) in RCA: 249] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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11
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Abstract
Advances in chromosome dynamics have increased our understanding of the significant role of telomeres and telomerase in cancer. Telomerase is expressed in almost all cancer cells but is inactive in most normal somatic cells. Therefore, telomerase is an important target for the design of therapeutic agents that might have minimal side effects. Herein, we evaluate current approaches to telomerase/telomere-targeted therapy, discuss the benefits and disadvantages, and speculate on the future direction of telomerase inhibitors as cancer therapeutics.
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12
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Maritz MF, Napier CE, Wen VW, MacKenzie KL. Targeting telomerase in hematologic malignancy. Future Oncol 2010; 6:769-89. [PMID: 20465390 DOI: 10.2217/fon.10.42] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Over the past two decades, it has become increasingly apparent that telomerase-mediated telomere maintenance plays a crucial role in hematopoiesis. Supporting evidence is underscored by recent findings of mutations in genes involved in telomerase-mediated telomere maintenance that contribute to the pathogenesis of bone marrow failure syndromes. More recently described telomere-independent functions of telomerase are also likely to contribute to both normal hematopoiesis and hematologic diseases. The high levels of telomerase detected in aggressive leukemias have fueled fervent investigation into diverse approaches to targeting telomerase in hematologic malignancies. Successful preclinical investigations that employed genetic strategies, oligonucleotides, small-molecule inhibitors and immunotherapy have resulted in a rapid translation to clinical trials. Further investigation of telomere-independent functions of telomerase and detailed preclinical studies of telomerase inhibition in both normal and malignant hematopoiesis will be invaluable for refining treatments to effectively and safely exploit telomerase as a therapeutic target in hematologic malignancies.
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Affiliation(s)
- Michelle F Maritz
- Children's Cancer Institute Australia for Medical Research, Lowy Cancer Research Centre, New South Wales, Australia
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13
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Abstract
Telomeres and telomerase play essential roles in the regulation of the lifespan of human cells. While normal human somatic cells do not or only transiently express telomerase and therefore shorten their telomeres with each cell division, most human cancer cells typically express high levels of telomerase and show unlimited cell proliferation. High telomerase expression allows cells to proliferate and expand long-term and therefore supports tumor growth. Owing to the high expression and its role, telomerase has become an attractive diagnostic and therapeutic cancer target. Imetelstat (GRN163L) is a potent and specific telomerase inhibitor and so far the only drug of its class in clinical trials. Here, we report on the structure and the mechanism of action of imetelstat as well as about the preclinical and clinical data and future prospects using imetelstat in cancer therapy.
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14
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Telomere and telomerase as targets for cancer therapy. Appl Biochem Biotechnol 2009; 160:1460-72. [PMID: 19412578 DOI: 10.1007/s12010-009-8633-9] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2009] [Accepted: 03/31/2009] [Indexed: 02/08/2023]
Abstract
Telomere maintenance and telomerase reactivation is essential for the transformation of most human cancer cells. Telomere shortening to the threshold length, mutations of the telomere-associated proteins, and/or telomerase RNA lead to telomeric dysfunction and therefore genomic instability. Telomerase up-regulation in 85% of human cancer cells has become a hallmark of cancers, hence a promising target for anticancer therapy. In this review, we discuss the mechanism of cancer due to telomere dysfunction and the resulting biological effects, the control of telomerase activity, and the new developments in cancer therapies targeting telomere and telomerase.
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15
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Keppler BR, Jarstfer MB. A high-throughput assay for a human telomerase protein-human telomerase RNA interaction. Anal Biochem 2006; 353:75-82. [PMID: 16620757 DOI: 10.1016/j.ab.2006.03.027] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2005] [Revised: 03/08/2006] [Accepted: 03/15/2006] [Indexed: 02/06/2023]
Abstract
The rapid rate at which cancer cells divide necessitates a mechanism for telomere maintenance, and in approximately 90% of all cancer types the enzyme telomerase is used to maintain the length of telomeric DNA. Telomerase is a multi-subunit enzyme that minimally contains a catalytic protein subunit, hTERT, and an RNA subunit, hTR. Proper assembly of telomerase is critical for its enzymatic activity and therefore is a requirement for the proliferation of most cancer cells. We have developed the first high-throughput screen capable of identifying small molecules that specifically perturb human telomerase assemblage. The screen uses a scintillation proximity assay to identify compounds that prevent a specific and required interaction between hTR and hTERT. Rather than attempting to disrupt all of the individual hTR-hTERT interactions, we focused the screen on the interaction of the CR4-CR5 domain of hTR with hTERT. The screen employs a biotin-labeled derivative of the CR4-CR5 domain of hTR that independently binds [(35)S]hTERT in a functionally relevant manner. The complex between hTERT and biotin-labeled RNA can be captured on streptavidin-coated scintillation proximity beads. Use of 96-well filter plates and a vacuum manifold enables rapid purification of the beads. After optimization, statistical evaluation of the screen generated a Z' factor of 0.6, demonstrating the high precision of the assay.
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Affiliation(s)
- Brian R Keppler
- Division of Medicinal Chemistry and Natural Products, School of Pharmacy, University of North Carolina, Chapel Hill, 27599, USA
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16
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Olaussen KA, Dubrana K, Domont J, Spano JP, Sabatier L, Soria JC. Telomeres and telomerase as targets for anticancer drug development. Crit Rev Oncol Hematol 2006; 57:191-214. [PMID: 16469501 DOI: 10.1016/j.critrevonc.2005.08.007] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2005] [Revised: 08/10/2005] [Accepted: 08/11/2005] [Indexed: 12/15/2022] Open
Abstract
In most human cancers, the telomere erosion problem has been bypassed through the activation of a telomere maintenance system (usually activation of telomerase). Therefore, telomere and telomerase are attractive targets for anti-cancer therapeutic interventions. Here, we review a large panel of strategies that have been explored to date, from small inhibitors of the catalytic sub-unit of telomerase to anti-telomerase immunotherapy and gene therapy. The many positive results that are reported from anti-telomere/telomerase assays suggest a prudent optimism for a possible clinical application in a close future. However, we discuss some of the main limits for these approaches of antitumour drug development and why significant work remains before a clinically useful drug can be proposed to patients.
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Affiliation(s)
- Ken André Olaussen
- Laboratory of Radiobiology and Oncology, DSV/DRR/LRO, CEA, Fontenay aux Roses, France
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17
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Cunningham AP, Love WK, Zhang RW, Andrews LG, Tollefsbol TO. Telomerase inhibition in cancer therapeutics: molecular-based approaches. Curr Med Chem 2006; 13:2875-88. [PMID: 17073634 PMCID: PMC2423208 DOI: 10.2174/092986706778521887] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Current standard cancer therapies (chemotherapy and radiation) often cause serious adverse off-target effects. Drug design strategies are therefore being developed that will more precisely target cancer cells for destruction while leaving surrounding normal cells relatively unaffected. Telomerase, widely expressed in most human cancers but almost undetectable in normal somatic cells, provides an exciting drug target. This review focuses on recent pharmacogenomic approaches to telomerase inhibition. Antisense oligonucleotides, RNA interference, ribozymes, mutant expression, and the exploitation of differential telomerase expression as a strategy for targeted oncolysis are discussed here in the context of cancer therapeutics. Reports of synergism between telomerase inhibitors and traditional cancer therapeutic agents are also analyzed.
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MESH Headings
- Drug Design
- Enzyme Inhibitors/pharmacology
- Enzyme Inhibitors/therapeutic use
- Humans
- Neoplasms/drug therapy
- Neoplasms/enzymology
- Neoplasms/pathology
- Oligonucleotides, Antisense/genetics
- Oligonucleotides, Antisense/pharmacology
- Oligonucleotides, Antisense/therapeutic use
- RNA, Antisense/genetics
- RNA, Antisense/pharmacology
- RNA, Antisense/therapeutic use
- RNA, Catalytic/genetics
- RNA, Catalytic/metabolism
- RNA, Untranslated/genetics
- RNA, Untranslated/metabolism
- Telomerase/antagonists & inhibitors
- Telomerase/genetics
- Telomerase/metabolism
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Affiliation(s)
- A P Cunningham
- Department of Biology, University of Alabama at Birmingham, AL 35294, USA
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18
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Yeo M, Rha SY, Jeung HC, Hu SX, Yang SH, Kim YS, An SW, Chung HC. Attenuation of telomerase activity by hammerhead ribozyme targeting human telomerase RNA induces growth retardation and apoptosis in human breast tumor cells. Int J Cancer 2005; 114:484-9. [PMID: 15551309 DOI: 10.1002/ijc.20720] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Ribozyme possesses specific endoribonuclease activity and catalyzes the hydrolysis of specific phosphodiester bonds, which results in the cleavage of target RNA sequences. Here, we evaluated the ability of hammerhead ribozymes targeting human telomerase RNA (hTR) to inhibit the catalytic activity of telomerase and the proliferation of cancer cells. Hammerhead ribozymes were designed against 7 NUX sequences located in open loops of the hTR secondary structure. We verified the ribozyme specificity by in vitro cleavage assay by using a synthetic RNA substrate. Subsequently, we introduced ribozyme expression vector into human breast tumor MCF-7 cells and assessed the biologic effects of ribozyme. Hammerhead ribozyme R1 targeting the template region of hTR efficiently cleaved hTR in vitro, and stable transfectants of this ribozyme induced the degradation of target hTR RNA and attenuated telomerase activity in MCF-7 cells. Moreover, the ribozyme R1 transfectant displayed a significant telomere shortening and a lower proliferation rate than parental cells. Clones with reduced proliferation capacity showed enlarged senescence-like shapes or highly differentiated dendritic morphologies of apoptosis. In conclusion, the inhibition of telomerase activity by hammerhead ribozyme targeting the template region of the hTR presents a promising strategy for inhibiting the growth of human breast cancer cells.
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Affiliation(s)
- Marie Yeo
- Cancer Metastasis Research Center, Yonsei Cancer Center, Department of Internal Medicine, Yonsei University College of Medicine, Seoul, South Korea
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19
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Zaffaroni N, Folini M. Use of ribozymes in validation of targets involved in tumor progression. DRUG DISCOVERY TODAY. TECHNOLOGIES 2004; 1:119-124. [PMID: 24981381 DOI: 10.1016/j.ddtec.2004.07.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The discovery over 20 years ago that RNA molecules called ribozymes are able to catalyze chemical reactions was a breakthrough in biology. Because of their high specificity, wide range of target selection and action before protein translation, ribozymes, mainly hammerhead ribozymes, have been largely used as specific suppressors of gene functions with the additional aim of validating disease-related genes as potential targets for new therapeutic interventions. However, the lack of suitable delivery systems still hampers the clinical development of ribozyme-based therapeutics. In this review, examples of ribozyme-based strategies to validate targets involved in tumor progression are reported together with a comparison of the advantages and disadvantages of ribozymes with respect to RNA interference technology.:
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Affiliation(s)
- Nadia Zaffaroni
- Department of Experimental Oncology, Unità Opertiva 10, Istituto Nazionale per lo Studio e la Cura dei Tumori, Via Venezian 1, 20133 Milan, Italy.
| | - Marco Folini
- Department of Experimental Oncology, Unità Opertiva 10, Istituto Nazionale per lo Studio e la Cura dei Tumori, Via Venezian 1, 20133 Milan, Italy
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Liu SX, Sun WS, Cao YL, Ma CH, Han LH, Zhang LN, Wang ZG, Zhu FL. Antisense oligonucleotide targeting at the initiator of hTERT arrests growth of hepatoma cells. World J Gastroenterol 2004; 10:366-70. [PMID: 14760759 PMCID: PMC4724927 DOI: 10.3748/wjg.v10.i3.366] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
AIM: To evaluate the inhibitory effect of antisense phosphorothioate oligonucleotide (asON) complementary to the initiator of human telomerase catalytic subunit (hTERT) on the growth of hepatoma cells.
METHODS: The as-hTERT was synthesized by using a DNA synthesizer. HepG2.2.15 cells were treated with as-hTERT at the concentration of 10 μmol/L. After 72 h, these cells were obtained for detecting growth inhibition, telomerase activity using the methods of MTT, TRAP-PCR-ELISA, respectively. BALB/c(nu/nu) mice were injected HepG2.2.15 cells and a human-nude mice model was obtained. There were three groups for anti-tumor activity study. Once tumors were established, these animals in the first group were administered as-hTERT and saline. Apoptosis of tumor cells was detected by FCM. In the 2nd group, the animals were injected HepG2.2.15 cells together with as-hTERT. In the third group, the animals were given as-hTERT 24 hours postinjection of HepG2.2.15 cells. The anti-HBV effects were assayed with ELISA in vitro and in vivo.
RESULTS: Growth inhibition was observed in cells treated with as-hTERT in vitro. A significant different in the value of A570 - A630 was found between cells treated with as-hTERT and control (P < 0.01) by MTT method. The telomerase activity of tumor cells treated with as-hTERT was reduced, the value of A450 nm was 0.42 compared to control (1.49) with TRAP-PCR-ELISA. The peak of apoptosis in tumor cells given as-hTERT was 21.12%, but not seen in saline-treated control. A prolonged period of carcinogenesis was observed in the second and third group animals. There was inhibitory effect on the expression of HBsAg and HBeAg in vivo and in vitro.
CONCLUSION: As-hTERT has an anti-tumor activity, which may be useful for gene therapy of tumors.
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Affiliation(s)
- Su-Xia Liu
- Institute of Immunology, Medical School of Shandong University, Wenhua West Road 44, Jinan 250012, Shandong Province, China
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Sun L, Wang X. Effects of allicin on both telomerase activity and apoptosis in gastric cancer SGC-7901 cells. World J Gastroenterol 2003; 9:1930-4. [PMID: 12970878 PMCID: PMC4656646 DOI: 10.3748/wjg.v9.i9.1930] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To investigate the effects of allicin on both telomerase activity and apoptosis in gastric cancer SGC-7901 cells.
METHODS: The gastric cancer SGC-7901 adenocarcinoma cells were treated with allicin and the cell cycle, inhibitory rate, apoptosis, telomerase activity and morphologic changes were studied by MTT assay, flow cytometry (FCM), TRAP-PCR-ELISA assay, light microscope, electron microscope respectively. Results were compared with that of AZT (3’-Azido-3’-deoxythymidine).
RESULTS: SGC-7901 cells were suppressed after exposure to allicin of 0.016 mg/mL, 0.05 mg/mL, and 0.1 mg/mL for 48 h. Compared with the control, the difference was significant (P < 0.05). Allicin could induce apoptosis of the cells in a dose-dependent and non-linear manner and increase the proportion of cells in the G2/M phase. Compared with the control, the difference was significant in terms of the percentage of cells in the G2/M phase (P < 0.05). Allicin could inhibit telomerase activity in a time-dependent and dose-dependent pattern. After exposure to allicin at 0.016 mg/mL for 24 hours, SGC-7901 cells showed typical morphologic change.
CONCLUSION: Allicin can inhibit telomerase activity and induce apoptosis of gastric cancer SGC-7901 cells. Allicin may be more effective than AZT.
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Affiliation(s)
- Li Sun
- Department of Oncology, Affiliated Hospital of Xuzhou Medical College, Xuzhou 221002, Jiangsu Province, China
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Abstract
A number of different approaches have been developed to inhibit telomerase activity in human cancer cells. Different components and types of inhibitors targeting various regulatory levels have been regarded as useful for telomerase inhibition. Most methods, however, rely on successive telomere shortening. This process is very slow and causes a long time lag between the onset of inhibition and the occurrence of senescence or apoptosis as a reversal of the immortal phenotype. Many telomerase inhibitors seem to be most efficient when combined with conventional chemotherapeutics. There are some promising approaches that seem to circumvent the slow way of telomere shortening and induce fast apoptosis in treated tumor cells. It has been demonstrated that telomerase may be involved in triggering apoptosis, but the underlying molecular mechanism remains unclear.
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Hao ZM, Luo JY, Cheng J, Wang QY, Yang GX. Design of a ribozyme targeting human telomerase reverse transcriptase and cloning of it’s gene. World J Gastroenterol 2003; 9:104-7. [PMID: 12508361 PMCID: PMC4728220 DOI: 10.3748/wjg.v9.i1.104] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To design a hammerhead ribozyme targeting human telomerase reverse transcriptase (hTERT) and clone it’s gene for future use in the study of tumor gene therapy.
METHODS: Using the software RNAstructure, the secondary structure of hTERT mRNA was predicted and the cleavage site of ribozyme was selected. A hammerhead ribozyme targeting this site was designed and bimolecular fold between the ribozyme and hTERT was predicted. The DNA encoding the ribozyme was synthesized and cloned into pGEMEX-1 and the sequence of the ribozyme gene was confirmed by DNA sequencing.
RESULTS: Triplet GUC at 1742 of hTERT mRNA was chosen as the cleavage site of the ribozyme. The designed ribozyme was comprised of 22 nt catalytic core and 17 nt flanking sequence. Computer-aided prediction suggested that the ribozyme and hTERT mRNA could cofold into a proper conformation. Endonuclease restriction and DNA sequencing confirmed the correct insertion of the ribozyme gene into the vector pGEMEX-1.
CONCLUSION: This fundamental work of successful designing and cloning of an anti-hTERT hammerhead ribozyme has paved the way for further study of inhibiting tumor cell growth by cleaving hTERT mRNA with ribozyme.
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Affiliation(s)
- Zhi-Ming Hao
- Department of Gastroenterology, 1st Hospital, Xi'an Jiaotong University, Xi'an 710061, Shaanxi Province, China.
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Abstract
Telomerase is a ribonucleoprotein that maintains telomeres and is essential for cellular immortality and tumour growth. The differential expression of telomerase in cancer cells makes it an attractive therapeutic target. Anti-sense oligonucleotides directed against the RNA template of hTR and small molecules that can interact and stabilise the G-quadruplex represent promising therapeutic strategies. Human trials investigating the potential role of the catalytic subunit hTERT as a universal cancer vaccine have already commenced. Alternative lengthening of telomeres (ALT) and efficacy delay remain important limitations to anti-telomerase therapy.
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Affiliation(s)
- Kefah Mokbel
- Institute of Cancer Genetics and Pharmacogenomics, Brunel University, and St George's and the Princess Grace Hospitals, London, UK.
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25
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Mergny JL, Riou JF, Mailliet P, Teulade-Fichou MP, Gilson E. Natural and pharmacological regulation of telomerase. Nucleic Acids Res 2002; 30:839-65. [PMID: 11842096 PMCID: PMC100331 DOI: 10.1093/nar/30.4.839] [Citation(s) in RCA: 273] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2001] [Revised: 11/29/2001] [Accepted: 11/29/2001] [Indexed: 01/14/2023] Open
Abstract
The extremities of eukaryotic chromosomes are called telomeres. They have a structure unlike the bulk of the chromosome, which allows the cell DNA repair machinery to distinguish them from 'broken' DNA ends. But these specialised structures present a problem when it comes to replicating the DNA. Indeed, telomeric DNA progressively erodes with each round of cell division in cells that do not express telomerase, a specialised reverse transcriptase necessary to fully duplicate the telomeric DNA. Telomerase is expressed in tumour cells but not in most somatic cells and thus telomeres and telomerase may be proposed as attractive targets for the discovery of new anticancer agents.
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Affiliation(s)
- Jean-Louis Mergny
- Laboratoire de Biophysique, Muséum National d'Histoire Naturelle, INSERM U 201, CNRS UMR 8646, 43 rue Cuvier, F-75005 Paris, France.
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26
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Abstract
Telomerase, a ribonucleoprotein enzyme, is considered as a potential target of cancer therapy because of its preferential expression in tumors. In particular, malignant gliomas are one of the best candidates for telomerase-targeted therapy. It is because malignant gliomas are predominantly telomerase-positive, while normal brain tissues do not express telomerase. In theory, there are two telomerase-associated therapeutic approaches for telomerase-positive tumors. One approach is the anti-telomerase cancer therapy to directly inhibit telomerase activity, resulting in apoptotic cell death or growth arrest. Two major components of the telomerase holoenzyme complex, the RNA template (hTER) and catalytic subunit (reverse transcriptase, hTERT) are well considered as therapeutic targets. The other approach is the telomerase-specific cancer therapy by targeting telomerase-expressing tumor cells as a means to directly kill the cells. Strategies using the transfer of therapeutic gene under the hTERT promoter system as well as immunotherapy directed against telomerase-positive cells are generally included. These telomerase-associated therapies are very promising for the treatment of malignant gliomas.
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Affiliation(s)
- Tadashi Komata
- The Center for Surgery Research, The Cleveland Clinic Foundation, Cleveland, Ohio, OH 44195, USA
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Zhang R, Wang X, Guo L, Xie H. Growth inhibition of BEL-7404 human hepatoma cells by expression of mutant telomerase reverse transcriptase. Int J Cancer 2002; 97:173-9. [PMID: 11774261 DOI: 10.1002/ijc.1597] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Human hepatocellular carcinoma (HCC) is one of the most common malignancies in Asia and Africa. Human telomerase reverse transcriptase (hTERT) is expressed in HCC but absent in normal human liver cells, which is consistent with the expression pattern of telomerase. In the present study, expression of a dominant-negative form of hTERT (DN-hTERT) resulted in inhibition of telomerase activity and decreased mean telomeric length of BEL-7404 human hepatoma cells, whereas expression of wild-type hTERT (WT-hTERT) and control vector had no such effects. Cell growth was inhibited by this mutant (DN-hTERT), which was consistent with the changes in telomerase level. Flattened large cells were found in late generations with the DN-hTERT treatment. When mean telomeric length of DN-hTERT-transfected cells reached a critical length (about 1.7 kb), apoptosis was induced. Tumorigenicity of DN-hTERT-expressing cells was eliminated in vivo. These data indicated that hTERT was essential for the growth of hepatoma cells. hTERT can also be used as an important target for anti-HCC drug screening.
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Affiliation(s)
- Rugang Zhang
- Department of Biotherapy, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, People's Republic of China
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Perry PJ, Arnold JR, Jenkins TC. Telomerase inhibitors for the treatment of cancer: the current perspective. Expert Opin Investig Drugs 2001; 10:2141-56. [PMID: 11772310 DOI: 10.1517/13543784.10.12.2141] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Telomerase is a holoenzyme responsible for the maintenance of telomeres, the protein-nucleic acid complexes at the ends of eukaryotic chromosomes that serve to maintain chromosomal stability and integrity. Telomerase activity is essential for the sustained proliferation of most immortal cells, including cancer cells. Since the discovery that telomerase activity is detected in 85-90% of all human tumours and tumour-derived cell lines but not in most normal somatic cells, telomerase has become the focus of much attention as a novel and potentially highly-specific target for the development of new anticancer chemotherapeutics. Herein we review the current perspective for the development of telomerase inhibitors as cancer chemotherapeutics. These include antisense strategies, reverse transcriptase inhibitors and compounds capable of interacting with high-order telomeric DNA tetraplex ("G-quadruplex") structures, so as to prevent enzyme access to the necessary linear telomere substrate. Critical appraisal of each individual approach is provided together with highlighted areas of likely future development.
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Affiliation(s)
- P J Perry
- Yorkshire Cancer Research Laboratory of Drug Design, Cancer Research Group, University of Bradford, Bradford, West Yorkshire BD7 1DP, UK.
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Abstract
Telomerase, the ribonucleoprotein enzyme that elongates chromosomal ends, or telomeres, is repressed in most normal somatic cells but reactivated in transformed cells to compensate for the progressive erosion of the telomeres during cell divisions. In accordance with this hypothesis, the presence of telomerase activity has been reported in more than 90% of human cancers, whereas most normal tissues or benign tumors contain low or undetectable telomerase activity. Reactivation of telomerase has also been widely reported in endocrine neoplasms and in hormone-related cancers. In the present study, we review the most recent publications on telomerase in these types of tumors. The hormonal regulation of telomerase activity and the possible strategies for cancer therapy based on the inhibition of telomerase has also been discussed.
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Affiliation(s)
- C Orlando
- Clinical Biochemistry Unit, Department of Clinical Physiopathology, University of Florence, viale Pieraccini 6, 50139, Florence, Italy.
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30
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Poole JC, Andrews LG, Tollefsbol TO. Activity, function, and gene regulation of the catalytic subunit of telomerase (hTERT). Gene 2001; 269:1-12. [PMID: 11376932 DOI: 10.1016/s0378-1119(01)00440-1] [Citation(s) in RCA: 190] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Recent interest in the regulation of telomerase, the enzyme that maintains chromosomal termini, has lead to the discovery and characterization of the catalytic subunit of telomerase, hTERT. Many studies have suggested that the transcription of hTERT represents the rate-limiting step in telomerase expression and key roles for hTERT have been implied in cellular aging, immortalization, and transformation. Before the characterization of the promoter of hTERT in 1999, regulatory mechanisms suggested for this gene were limited to speculation. The successful cloning and characterization of the hTERT 5' gene regulatory region has enabled its formal investigation and analysis of potential mechanisms controlling hTERT expression. Although these studies have provided important information about hTERT gene regulation, there has been some confusion regarding the nucleotide boundaries of this region, the location, number, and importance of various transcription factor binding motifs, and the results of promoter activity assays. We feel that this uncertainty, combined with the sheer volume of recent publications on hTERT regulation, calls for consolidation and review. In this analysis we examine recent advances in the regulation of the hTERT gene and attempt to resolve discrepancies resulting from the nearly simultaneous nature of publications in this fast-moving area. Additionally, we aim to summarize the extant knowledge of hTERT gene regulation and its role in important biological processes such as cancer and aging.
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Affiliation(s)
- J C Poole
- Department of Biology, University of Alabama at Birmingham, Birmingham, AL 35294-1170, USA
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Affiliation(s)
- CLAUDIO ORLANDO
- From the Clinical Biochemistry Unit Department of Clinical Physiopathology, University of Florence and Division of Urology, Department of Surgery, University of Pisa, Pisa, Italy
| | - STEFANIA GELMINI
- From the Clinical Biochemistry Unit Department of Clinical Physiopathology, University of Florence and Division of Urology, Department of Surgery, University of Pisa, Pisa, Italy
| | - CESARE SELLI
- From the Clinical Biochemistry Unit Department of Clinical Physiopathology, University of Florence and Division of Urology, Department of Surgery, University of Pisa, Pisa, Italy
| | - MARIO PAZZAGLI
- From the Clinical Biochemistry Unit Department of Clinical Physiopathology, University of Florence and Division of Urology, Department of Surgery, University of Pisa, Pisa, Italy
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Abstract
The development of malignant neoplasms is a multistep process and it is believed that multiple genetic alterations are involved. The progression of neoplastic lesions is also characterized by reactivation of telomerase, a ribonucleoprotein complex enzyme that adds telomere repeats at the ends of chromosomes. In view of the close association between telomerase and malignancy, this molecule may prove to be a useful marker for malignancy. This review focuses on the diagnostic and therapeutic potential of telomerase. The experimental data for telomerase assays with the potential for oral cancer detection and diagnosis are also reviewed.
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Affiliation(s)
- T Sumida
- Department of Oral and Maxillofacial Surgery, Ehime University School of Medicine, Shitsukawa, Shigenobu-cho, Onsen-gun, 791-0295, Ehime, Japan.
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