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Yang R, Han Y, Guan X, Hong Y, Meng J, Ding S, Long Q, Yi W. Regulation and clinical potential of telomerase reverse transcriptase (TERT/hTERT) in breast cancer. Cell Commun Signal 2023; 21:218. [PMID: 37612721 PMCID: PMC10463831 DOI: 10.1186/s12964-023-01244-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Accepted: 07/23/2023] [Indexed: 08/25/2023] Open
Abstract
Telomerase reverse transcriptase (TERT/hTERT) serves as the pivotal catalytic subunit of telomerase, a crucial enzyme responsible for telomere maintenance and human genome stability. The high activation of hTERT, observed in over 90% of tumors, plays a significant role in tumor initiation and progression. An in-depth exploration of hTERT activation mechanisms in cancer holds promise for advancing our understanding of the disease and developing more effective treatment strategies. In breast cancer, the expression of hTERT is regulated by epigenetic, transcriptional, post-translational modification mechanisms and DNA variation. Besides its canonical function in telomere maintenance, hTERT exerts non-canonical roles that contribute to disease progression through telomerase-independent mechanisms. This comprehensive review summarizes the regulatory mechanisms governing hTERT in breast cancer and elucidates the functional implications of its activation. Given the overexpression of hTERT in most breast cancer cells, the detection of hTERT and its associated molecules are potential for enhancing early screening and prognostic evaluation of breast cancer. Although still in its early stages, therapeutic approaches targeting hTERT and its regulatory molecules show promise as viable strategies for breast cancer treatment. These methods are also discussed in this paper. Video Abstract.
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Affiliation(s)
- Ruozhu Yang
- Department of General Surgery, the Second Xiangya Hospital of Central South University, 139 Middle Renmin Road, Changsha, 410011, China
| | - Yi Han
- Department of General Surgery, the Second Xiangya Hospital of Central South University, 139 Middle Renmin Road, Changsha, 410011, China
| | - Xinyu Guan
- Department of General Surgery, the Second Xiangya Hospital of Central South University, 139 Middle Renmin Road, Changsha, 410011, China
| | - Yue Hong
- Department of General Surgery, the Second Xiangya Hospital of Central South University, 139 Middle Renmin Road, Changsha, 410011, China
| | - Jiahao Meng
- Department of General Surgery, the Second Xiangya Hospital of Central South University, 139 Middle Renmin Road, Changsha, 410011, China
| | - Shirong Ding
- Department of Oncology, the Second Xiangya Hospital of Central South University, 139 Middle Renmin Road, Changsha, 410011, China.
| | - Qian Long
- Department of General Surgery, the Second Xiangya Hospital of Central South University, 139 Middle Renmin Road, Changsha, 410011, China.
| | - Wenjun Yi
- Department of General Surgery, the Second Xiangya Hospital of Central South University, 139 Middle Renmin Road, Changsha, 410011, China.
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Smith EW, Lattmann S, Liu ZB, Ahsan B, Rhodes D. Insights into POT1 structural dynamics revealed by cryo-EM. PLoS One 2022; 17:e0264073. [PMID: 35176105 PMCID: PMC8853558 DOI: 10.1371/journal.pone.0264073] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Accepted: 02/02/2022] [Indexed: 12/13/2022] Open
Abstract
Telomeres are protein-DNA complexes that protect the ends of linear eukaryotic chromosomes. Mammalian telomeric DNA consists of 5′-(TTAGGG)n-3′ double-stranded repeats, followed by up to several hundred bases of a 3′ single-stranded G-rich overhang. The G-rich overhang is bound by the shelterin component POT1 which interacts with TPP1, the component involved in telomerase recruitment. A previously published crystal structure of the POT1 N-terminal half bound to the high affinity telomeric ligand 5′-TTAGGGTTAG-3′ showed that the first six nucleotides, TTAGGG, are bound by the OB1 fold, while the adjacent OB2 binds the last four, TTAG. Here, we report two cryo-EM structures of full-length POT1 bound by the POT1-binding domain of TPP1. The structures differ in the relative orientation of the POT1 OB1 and OB2, suggesting that these two DNA-binding OB folds take up alternative conformations. Supporting DNA binding studies using telomeric ligands in which the OB1 and OB2 binding sites were spaced apart, show that POT1 binds with similar affinities to spaced or contiguous binding sites, suggesting plasticity in DNA binding and a role for the alternative conformations observed. A likely explanation is that the structural flexibility of POT1 enhances binding to the tandemly arranged telomeric repeats and hence increases telomere protection.
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Affiliation(s)
- Emmanuel W. Smith
- NTU Institute of Structural Biology, Nanyang Technological University, Singapore, Singapore
| | - Simon Lattmann
- NTU Institute of Structural Biology, Nanyang Technological University, Singapore, Singapore
| | - Zhehui Barry Liu
- NTU Institute of Structural Biology, Nanyang Technological University, Singapore, Singapore
| | - Bilal Ahsan
- NTU Institute of Structural Biology, Nanyang Technological University, Singapore, Singapore
| | - Daniela Rhodes
- NTU Institute of Structural Biology, Nanyang Technological University, Singapore, Singapore
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
- * E-mail:
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3
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Anticancer potential of allicin: A review. Pharmacol Res 2022; 177:106118. [DOI: 10.1016/j.phrs.2022.106118] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 02/03/2022] [Accepted: 02/03/2022] [Indexed: 12/12/2022]
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Vinchure OS, Whittemore K, Kushwah D, Blasco MA, Kulshreshtha R. miR-490 suppresses telomere maintenance program and associated hallmarks in glioblastoma. Cell Mol Life Sci 2021; 78:2299-2314. [PMID: 32970185 PMCID: PMC11073096 DOI: 10.1007/s00018-020-03644-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 09/09/2020] [Accepted: 09/12/2020] [Indexed: 01/15/2023]
Abstract
Glioblastoma (GBM) is the most aggressive cancer of central nervous system with worst patient outcome. Telomere maintenance is a crucial mechanism governing GBM initiation and progression making it an attractive target. microRNAs (miRNAs) have shown therapeutic potential in GBM. Earlier, we showed miR-490 is downregulated in GBM patients and plays a tumor suppressive role. Here, we show that miR-490 regulates telomere maintenance program in GBM by directly targeting Telomeric Repeat-binding Factor 2 (TERF2) of the shelterin complex, Tankyrase 2 (TNKS2) and Serine/Threonine-protein kinase, SMG1. Overexpression of miR-490 resulted in effects characteristic to hampered telomere maintenance via TERF2 inhibition. These include induction of telomere dysfunction-induced foci and global DNA damage (53BP1 foci), along with an increase in p-γH2AX levels. Further, it led to inhibition of telomere maintenance hallmarks via reduced stemness (SOX2 and SOX4 downregulation) and induction of senescence (H3K9me3 marks gain and SIRT1 downregulation). It also initiated downstream DNA damage response (DDR) leading to p53 pathway activation. Moreover, microarray data analysis highlighted an overlap between miR-490 expression and REST-inhibition responses in GBM. Thus, miR-490-mediated targeting of telomere maintenance could be therapeutically important in GBM.
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Affiliation(s)
- Omkar Suhas Vinchure
- Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology, Delhi, New Delhi, 110016, India
| | - Kurt Whittemore
- Telomeres and Telomerase Group, Spanish National Cancer Research Centre (CNIO), Melchor Fernandez Almagro 3, 28029, Madrid, Spain
| | - Deependra Kushwah
- Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology, Delhi, New Delhi, 110016, India
| | - Maria A Blasco
- Telomeres and Telomerase Group, Spanish National Cancer Research Centre (CNIO), Melchor Fernandez Almagro 3, 28029, Madrid, Spain
| | - Ritu Kulshreshtha
- Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology, Delhi, New Delhi, 110016, India.
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Hirokawa T, Arimasu Y, Chiba T, Nakazato Y, Fujiwara M, Kamma H. Regulatory Single Nucleotide Polymorphism Increases TERT Promoter Activity in Thyroid Carcinoma Cells. Pathobiology 2020; 87:338-344. [PMID: 33227798 DOI: 10.1159/000509752] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Accepted: 06/23/2020] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND/AIM The telomerase reverse transcriptase (TERT) promoter has a regulatory single nucleotide polymorphism (rSNP), rs2853669, and occasionally shows point mutations C228T and C250T. Although C228T and C250T have been well examined to increase TERT promoter activity and are known as risk factors for thyroid carcinoma, the significance of rs2853669 has not been well investigated. This study aimed to clarify the influence of rs2853669 on TERT promoter activity in thyroid carcinoma cells. MATERIALS Seven of 8 examined thyroid cell lines had rs2853669, 5 had C228T, and 1 had C250T. RESULTS Three papillary thyroid carcinoma cell lines, harboring both rs2853669 and C228T, showed higher TERT mRNA expression on real-time PCR than the other cell lines. Anaplastic thyroid carcinoma cell lines, in contrast, showed variable TERT mRNA expression depending on the combination of rs2853669, C228T, and C250T. Luciferase assays, performed to compare the influences of rs2853669, C228T, and C250T on TERT promoter activity in thyroid carcinoma, showed that rs2853669, as well as C228T, increased the promoter activity, and the combination of rs2853669 and C228T increased the promoter activity even more strongly than C228T alone. CONCLUSION We conclude that the presence of rs2853669 within the TERT promoter could be as significant as the C228T mutation in thyroid carcinoma.
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Affiliation(s)
- Tatsuya Hirokawa
- Department of Pathology, School of Medicine, Kyorin University, Mitaka, Japan
| | - Yuu Arimasu
- Department of Pathology, School of Medicine, Kyorin University, Mitaka, Japan
| | - Tomohiro Chiba
- Department of Pathology, School of Medicine, Kyorin University, Mitaka, Japan.,Department of Pathology, The Cancer Institute, Japanese Foundation for Cancer Research, Tokyo, Japan
| | - Yoko Nakazato
- Department of Respiratory and Thyroid Surgery, School of Medicine, Kyorin University, Mitaka, Japan
| | - Masachika Fujiwara
- Department of Pathology, School of Medicine, Kyorin University, Mitaka, Japan
| | - Hiroshi Kamma
- Department of Pathology, School of Medicine, Kyorin University, Mitaka, Japan,
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Pu X, Luo A, Su H, Zhang K, Tian C, Chen B, Chai P, Xia X. Optimization and mechanism of postponing aging of polysaccharides from Chinese herbal medicine formula. Toxicol Res (Camb) 2020; 9:239-248. [PMID: 32670555 DOI: 10.1093/toxres/tfaa020] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Revised: 03/03/2020] [Indexed: 11/14/2022] Open
Abstract
To study the extraction technology of polysaccharides (AAP) from Chinese herbal medicine formula and its mechanism of delaying aging. First, L9(3)4 orthogonal test was used to optimize the optimal enzyme-assisted extraction parameters of polysaccharides. And the anti-aging effects was evaluated by detecting mitochondrial function, protein, DNA, adhesion molecules and cell cycle in aging rats. The optimal extraction process parameters were the cellulase concentration of 1.5%, the pH at 5, the enzyme temperature at 50°C and the extraction time of 180 min. The anti-aging results showed that AAP can effectively increase the activities of malate dehydrogenase, succinate dehydrogenase and superoxide dismutase. It also can decrease the activity of monoamine oxidase and methane dicarboxylic aldehyde levels in the brain tissue. Meanwhile, the polysaccharides enhanced telomerase activity while reduced p16 protein expression of the brain mitochondria. In addition, the polysaccharides continued to improve heart damage and significantly lessen mitochondrial DNA concentrations. For a certain period of time, it also enhanced the activity of superoxide dismutase, reduced glutathione, glutathione peroxidase and decreased protein carbonyl and methane dicarboxylic aldehyde content of kidney in D-galactose-induced aging rats. Furthermore, the polysaccharides restored the number of cells in the peripheral blood lines and BMNC through inhibiting the drop of the number of red blood cells, white blood cells, platelets in the peripheral blood and bone marrow mononuclear cell of the aging rats. At the same time, AAP accelerated G1 phase cell to enter S phase in cell cycle in aging rats. Our research suggests that the polysaccharides may be a potential anti-aging agent and can be further developed as a functional food or new drug to delay aging or treat aging-related diseases.
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Affiliation(s)
- Xiuying Pu
- School of Life Science and Engineering, Lanzhou University of Technology, The Key Lab of Screening, Evaluation and Advanced Processing of TCM and Tibetan Medicine, Gansu Educational Department, No. 287, Langongping Road, Qilihe District, Lanzhou 730050, Gansu, China
| | - Amiao Luo
- School of Life Science and Engineering, Lanzhou University of Technology, The Key Lab of Screening, Evaluation and Advanced Processing of TCM and Tibetan Medicine, Gansu Educational Department, No. 287, Langongping Road, Qilihe District, Lanzhou 730050, Gansu, China
| | - Hui Su
- School of Life Science and Engineering, Lanzhou University of Technology, The Key Lab of Screening, Evaluation and Advanced Processing of TCM and Tibetan Medicine, Gansu Educational Department, No. 287, Langongping Road, Qilihe District, Lanzhou 730050, Gansu, China
| | - Kaili Zhang
- School of Life Science and Engineering, Lanzhou University of Technology, The Key Lab of Screening, Evaluation and Advanced Processing of TCM and Tibetan Medicine, Gansu Educational Department, No. 287, Langongping Road, Qilihe District, Lanzhou 730050, Gansu, China
| | - Changyi Tian
- School of Life Science and Engineering, Lanzhou University of Technology, The Key Lab of Screening, Evaluation and Advanced Processing of TCM and Tibetan Medicine, Gansu Educational Department, No. 287, Langongping Road, Qilihe District, Lanzhou 730050, Gansu, China
| | - Bo Chen
- School of Life Science and Engineering, Lanzhou University of Technology, The Key Lab of Screening, Evaluation and Advanced Processing of TCM and Tibetan Medicine, Gansu Educational Department, No. 287, Langongping Road, Qilihe District, Lanzhou 730050, Gansu, China
| | - Pengdi Chai
- School of Life Science and Engineering, Lanzhou University of Technology, The Key Lab of Screening, Evaluation and Advanced Processing of TCM and Tibetan Medicine, Gansu Educational Department, No. 287, Langongping Road, Qilihe District, Lanzhou 730050, Gansu, China
| | - Xiaoyu Xia
- School of Life Science and Engineering, Lanzhou University of Technology, The Key Lab of Screening, Evaluation and Advanced Processing of TCM and Tibetan Medicine, Gansu Educational Department, No. 287, Langongping Road, Qilihe District, Lanzhou 730050, Gansu, China
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Transient induction of telomerase expression mediates senescence and reduces tumorigenesis in primary fibroblasts. Proc Natl Acad Sci U S A 2019; 116:18983-18993. [PMID: 31481614 PMCID: PMC6754593 DOI: 10.1073/pnas.1907199116] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Telomerase is an enzymatic ribonucleoprotein complex that acts as a reverse transcriptase in the elongation of telomeres. Telomerase activity is well documented in embryonic stem cells and the vast majority of tumor cells, but its role in somatic cells remains to be understood. Here, we report an unexpected function of telomerase during cellular senescence and tumorigenesis. We crossed Tert heterozygous knockout mice (mTert +/- ) for 26 generations, during which time there was progressive shortening of telomeres, and obtained primary skin fibroblasts from mTert +/+ and mTert -/- progeny of the 26th cross. As a consequence of insufficient telomerase activities in prior generations, both mTert +/+ and mTert -/- fibroblasts showed comparable and extremely short telomere length. However, mTert -/- cells approached cellular senescence faster and exhibited a significantly higher rate of malignant transformation than mTert +/+ cells. Furthermore, an evident up-regulation of telomerase reverse-transcriptase (TERT) expression was detected in mTert +/+ cells at the presenescence stage. Moreover, removal or down-regulation of TERT expression in mTert +/+ and human primary fibroblast cells via CRISPR/Cas9 or shRNA recapitulated mTert -/- phenotypes of accelerated senescence and transformation, and overexpression of TERT in mTert -/- cells rescued these phenotypes. Taking these data together, this study suggests that TERT has a previously underappreciated, protective role in buffering senescence stresses due to short, dysfunctional telomeres, and preventing malignant transformation.
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8
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Ye Y, Yang Z, Lei J. Stochastic Telomere Shortening and the Route to Limitless Replicative Potential. J Comput Biol 2019; 26:350-363. [PMID: 30762424 DOI: 10.1089/cmb.2018.0234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
In human tissues, the replicative potential of stem cells is limited by the shortening of telomere, limitless replicative potential is a hallmark of cancer. Telomere length changes stochastically during cell division mainly due to the competition between the end replication problem and telomerase, short telomere can lead to replicative senescence and cell apoptosis. Here, we investigate how stochastic changes of telomere length in individual cells may affect the population dynamics of clonal growth. We established a computational model that couples telomerase-regulated stochastic telomere length changes with the replicative potential of clones. Model simulations reveal qualitative dependence of clone proliferation potential with activities of telomerase; mutations in cells to alter the activities of telomerase and its inhibitors can induce abnormal tissue growth and lead to limitless replicative potential.
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Affiliation(s)
- Yusong Ye
- 1 School of Mathematics and Systems Science and LMIB, Beihang University, Beijing, China
| | - Zhuoqin Yang
- 1 School of Mathematics and Systems Science and LMIB, Beihang University, Beijing, China
| | - Jinzhi Lei
- 2 Zhou Pei-Yuan Center for Applied Mathematics, MOE Key Laboratory of Bioinformatics, Tsinghua University, Beijing, China
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9
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Drabik G, Kaszuba-Zwoińska J, Wiśniowski Z, Konieczny L, Roterman I. Chromatin 3D – will it make understanding of cancer transformation finally possible? BIO-ALGORITHMS AND MED-SYSTEMS 2018. [DOI: 10.1515/bams-2018-0002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
Despite enormous progress in molecular analysis of cancer cell genomes, the mechanism of tumorigenesis remains unclear. The information present in the genome is not limited to the DNA sequence itself. Indeed, a significant portion of this information is concealed in the spatial structure of chromatin. Ongoing scientific studies that focus on the three-dimensional structure of chromatin raise hopes of arriving at a general explanation of the cancer transformation phenomenon.
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Guruprasad KP, Dash S, Shivakumar MB, Shetty PR, Raghu KS, Shamprasad BR, Udupi V, Acharya RV, Vidya PB, Nayak J, Mana AE, Moni R, Sankaran MT, Satyamoorthy K. Influence of Amalaki Rasayana on telomerase activity and telomere length in human blood mononuclear cells. J Ayurveda Integr Med 2017; 8:105-112. [PMID: 28602428 PMCID: PMC5497001 DOI: 10.1016/j.jaim.2017.01.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2016] [Revised: 01/13/2017] [Accepted: 01/13/2017] [Indexed: 12/20/2022] Open
Abstract
Background Indian traditional medicine practices use defined rasayana preparations to improve the quality of life in aged individuals. Amalaki Rasayana is one such rasayana prepared from the fruits of Phyllanthus emblica and is popularly used to prevent or treat various age related health conditions. Telomerase activity in the cells maintains telomere length and is implicated in ageing and various diseases wherein the shortening of telomere during ageing is controlled chiefly by the telomerase activity. Objective In the present study, we investigated telomerase activity and telomere length in the peripheral blood mononuclear cells of aged individuals administered with Amalaki Rasayana. Materials and methods Amalaki Rasayana was administered to healthy, aged (45–60 years) volunteers for 45 days after koshta shuddhi procedure. The telomerase activity and telomere length were analyzed on 0, 45th and 90th days of Amalaki Rasayana administration in peripheral blood mononuclear cells from these individuals and compared with age-matched placebo group and young volunteers (22–30 years). The data were compared between the groups. Results The results indicated an increase in telomerase activity with no discernible change in telomere length in the Amalaki administered participants. The comparison between young and aged participants revealed higher telomerase activity in young participants with no significant differences in telomere length. Conclusion The data indicate that the maintenance of telomere length is facilitated by an increase in telomerase activity upon rasayana administration in aged individuals and Amalaki Rasayana may prevent the erosion of telomeres over a period of time in aged individuals to promote healthy ageing.
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Affiliation(s)
- Kanive P Guruprasad
- School of Life Sciences, Manipal University, Planetarium Complex, Manipal, 576 104, Karnataka, India
| | - Sweta Dash
- School of Life Sciences, Manipal University, Planetarium Complex, Manipal, 576 104, Karnataka, India
| | - Marigowda B Shivakumar
- School of Life Sciences, Manipal University, Planetarium Complex, Manipal, 576 104, Karnataka, India
| | - Pavithra R Shetty
- School of Life Sciences, Manipal University, Planetarium Complex, Manipal, 576 104, Karnataka, India
| | - Kothanahalli S Raghu
- School of Life Sciences, Manipal University, Planetarium Complex, Manipal, 576 104, Karnataka, India
| | - Bhanuvalli R Shamprasad
- School of Life Sciences, Manipal University, Planetarium Complex, Manipal, 576 104, Karnataka, India
| | - Vishwanatha Udupi
- School of Life Sciences, Manipal University, Planetarium Complex, Manipal, 576 104, Karnataka, India
| | - Raviraj V Acharya
- Department of Medicine, Kasturba Medical College Hospital, Manipal University, Manipal, 576 104, Karnataka, India
| | - Prasanna B Vidya
- Sri Dharmasthala Manjunatheshwara College of Ayurveda, Kuthpady, Udyavara, Udupi, 574 118, Karnataka, India
| | - Jayakrishna Nayak
- Sri Dharmasthala Manjunatheshwara College of Ayurveda, Kuthpady, Udyavara, Udupi, 574 118, Karnataka, India
| | - Anandan E Mana
- Ayurvedic Hospital and Research Centre, Arya Vaidya Sala, Kottakkal, 676 503, Mallapuram District, Kerala, India
| | - Rajesh Moni
- Ayurvedic Hospital and Research Centre, Arya Vaidya Sala, Kottakkal, 676 503, Mallapuram District, Kerala, India
| | - Muraleedharan T Sankaran
- Ayurvedic Hospital and Research Centre, Arya Vaidya Sala, Kottakkal, 676 503, Mallapuram District, Kerala, India
| | - Kapaettu Satyamoorthy
- School of Life Sciences, Manipal University, Planetarium Complex, Manipal, 576 104, Karnataka, India.
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Meng Y, Yu Z, Wu Y, Du T, Chen S, Meng F, Su N, Ma Y, Li X, Sun S, Zhang G. Cell-based immunotherapy with cytokine-induced killer (CIK) cells: From preparation and testing to clinical application. Hum Vaccin Immunother 2017; 13:1-9. [PMID: 28301281 PMCID: PMC5489295 DOI: 10.1080/21645515.2017.1285987] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Revised: 01/11/2017] [Accepted: 01/19/2017] [Indexed: 12/24/2022] Open
Abstract
Cell-based immunotherapy holds promise in the quest for the treatment of cancer, having potential synergy with surgery, chemotherapy and radiotherapy. As a novel approach for adoptive cell-based immunotherapy, cytokine-induced killer (CIK) cells have moved from the 'bench to bedside'. CIK cells are a heterogeneous subset of ex-vitro expanded, polyclonal T-effector cells with both natural killer (NK) and T-cell properties, which present potent non-major histocompatibility complex-restricted cytotoxicity against a variety of tumor target cells. Initial clinical studies on CIK cell therapy have provided encouraging results and revealed synergistic antitumor effects when combined with standard therapeutic procedures. At the same time, issues such as inadequate quality control and quantity of CIK cells as well as exaggerated propaganda were continuously emerging. Thus, the Ministry of Health in China stopped CIK cell therapy in May 2016, which was a major setback for the innovation of CIK cell-based immunotherapy. Thus, it is very important to modify technical criteria to develop a standardized operation procedure (SOP) and standardized system for evaluating antitumor efficacy in a safe way.
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Affiliation(s)
- Yiming Meng
- Central Laboratory, Cancer Hospital of China Medical University, Dadong District, Shenyang, China
| | - Zhifu Yu
- Department of Epidemiology, Cancer Hospital of China Medical University, Dadong District, Shenyang, China
| | - Yefeng Wu
- Central Laboratory, Cancer Hospital of China Medical University, Dadong District, Shenyang, China
| | - Tianzhao Du
- Central Laboratory, Cancer Hospital of China Medical University, Dadong District, Shenyang, China
| | - Shi Chen
- Central Laboratory, Cancer Hospital of China Medical University, Dadong District, Shenyang, China
| | - Fanjuan Meng
- Central Laboratory, Cancer Hospital of China Medical University, Dadong District, Shenyang, China
| | - Nan Su
- Central Laboratory, Cancer Hospital of China Medical University, Dadong District, Shenyang, China
| | - Yushu Ma
- Central Laboratory, Cancer Hospital of China Medical University, Dadong District, Shenyang, China
| | - Xiaoxi Li
- Central Laboratory, Cancer Hospital of China Medical University, Dadong District, Shenyang, China
| | - Sulan Sun
- Central Laboratory, Cancer Hospital of China Medical University, Dadong District, Shenyang, China
| | - Guirong Zhang
- Central Laboratory, Cancer Hospital of China Medical University, Dadong District, Shenyang, China
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12
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Belda R, García-España E, Morris GA, Steed JW, Aguilar JA. Guanosine-5'-Monophosphate Polyamine Hybrid Hydrogels: Enhanced Gel Strength Probed by z-Spectroscopy. Chemistry 2017; 23:7755-7760. [PMID: 28403539 DOI: 10.1002/chem.201700642] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Indexed: 01/25/2023]
Abstract
The self-assembling tendencies of guanosine-5'-monophosphate (GMP) can be drastically increased using polyamines, with potential applications in the production of biocompatible smart materials, as well as for the design of antitumor drugs based on G-quadruplex stabilization. Results from scanning electron microscopy (SEM), wide angle X-ray scattering (WAXS), rheology, and nuclear magnetic resonance (NMR) z-spectroscopy studies are presented.
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Affiliation(s)
- Raquel Belda
- Department of Chemistry, Durham University, South Road, Durham, DH1 3LE, UK.,Instituto de Ciencia Molecular, Universidad de Valencia, C/ Catedrático José Beltrán n°. 2, 46980, Paterna, Spain.,School of Chemistry, University of Manchester, Oxford Road, Manchester, M13 9PL, UK
| | - Enrique García-España
- Instituto de Ciencia Molecular, Universidad de Valencia, C/ Catedrático José Beltrán n°. 2, 46980, Paterna, Spain
| | - Gareth A Morris
- School of Chemistry, University of Manchester, Oxford Road, Manchester, M13 9PL, UK
| | - Jonathan W Steed
- Department of Chemistry, Durham University, South Road, Durham, DH1 3LE, UK
| | - Juan A Aguilar
- Department of Chemistry, Durham University, South Road, Durham, DH1 3LE, UK.,School of Chemistry, University of Manchester, Oxford Road, Manchester, M13 9PL, UK
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Kang MK, Park NH. Conversion of Normal To Malignant Phenotype: Telomere Shortening, Telomerase Activation, and Genomic Instability During Immortalization of Human Oral Keratinocytes. ACTA ACUST UNITED AC 2016; 12:38-54. [PMID: 11349961 DOI: 10.1177/10454411010120010301] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Normal somatic cells terminate their replicative life span through a pathway leading to cellular senescence, which is triggered by activation of p53 and/or pRb in response to critically shortened telomere DNA. Potentially neoplastic cells must first overcome the senescence checkpoint mechanisms and subsequently activate telomerase to propagate indefinitely. Although telomerase activation is closely associated with cellular immortality, telomerase alone is not sufficient to warrant tumorigenicity. Environmental factors, including chemical carcinogens and viral infection, often contribute to aberrant changes leading to tumorigenic conversion of normal cells. Of particular importance in oral cancer development are tobacco-related chemical carcinogens and human papillomavirus (HPV) infection. To describe the molecular mechanisms by which these environmental factors facilitate the genesis of oral cancer, we first established an in vitro multistep oral carcinogenesis model by sequential exposure of normal human oral keratinocytes (NHOK) to "high risk" HPV and chemical carcinogens. Upon introduction of the HPV genome, the cells bypassed the senescence checkpoint and entered into an extended, but not immortal, life span during which telomere DNA continued to shorten. In a few immortal clones surviving beyond the crisis, we found a marked elevation of telomerase activity and stabilization of telomere length. Furthermore, the E6 and E7 oncoproteins of "high risk" HPV disrupted the cell cycle control and DNA repair in immortalized HOK, and enhanced mutation frequency resulting from genomic instability. However, HPV infection alone failed to give rise to a tumorigenic cell population, which required further exposure to chemical carcinogens in addition to HPV infection. Analysis of the data presented suggests that oral carcinogenesis is a series of discrete genetic alterations that result from a continued genotoxic challenge by environmental risk factors. Our in vitro model may be useful for investigators with interest in furthering our understanding of oral carcinogenesis.
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Affiliation(s)
- M K Kang
- School of Dentistry and Dental Research Institute, University of California, Los Angeles 90095, USA
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Chen R, Zhu J, Dong Y, He C, Hu X. Suppressor of Ty homolog-5, a novel tumor-specific human telomerase reverse transcriptase promoter-binding protein and activator in colon cancer cells. Oncotarget 2016; 6:32841-55. [PMID: 26418880 PMCID: PMC4741733 DOI: 10.18632/oncotarget.5301] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2015] [Accepted: 09/05/2015] [Indexed: 12/14/2022] Open
Abstract
The human telomerase reverse transcriptase (hTERT) promoter promotes differential hTERT gene expression in tumor cells and normal cells. However, information on the mechanisms underlying the differential hTERT transcription and induction of telomerase activity in tumor cells is limited. In the present study, suppressor of Ty homolog-5 (SPT5), a protein encoded by the SUPT5H gene, was identified as a novel tumor-specific hTERT promoter-binding protein and activator in colon cancer cells. We verified the tumor-specific binding activity of SPT5 to the hTERT promoter in vitro and in vivo and detected high expression levels of SUPT5H in colorectal cancer cell lines and primary human colorectal cancer tissues. SUPT5H was more highly expressed in colorectal cancer cases with distant metastasis than in cases without distant metastasis. Inhibition of endogenous SUPT5H expression by SUPT5H gene-specific short hairpin RNAs effectively attenuated hTERT promoter-driven green fluorescent protein (GFP) expression, whereas no detectable effects on CMV promoter-driven GFP expression in the same cells were observed. In addition, inhibition of SUPT5H expression not only effectively repressed telomerase activity, accelerated telomere shortening, and promoted cell senescence in colon cancer cells, but also suppressed cancer cell growth and migration. Our results demonstrated that SPT5 contributes to the up-regulation of hTERT expression and tumor development, and SUPT5H may potentially be used as a novel tumor biomarker and/or cancer therapeutic target.
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Affiliation(s)
- Rui Chen
- Department of Colorectal Surgery, Sir Run Run Shaw Hospital, Zhejiang University, Hangzhou 310016, China
| | - Jing Zhu
- Department of Colorectal Surgery, Sir Run Run Shaw Hospital, Zhejiang University, Hangzhou 310016, China
| | - Yong Dong
- Department of Colorectal Surgery, Sir Run Run Shaw Hospital, Zhejiang University, Hangzhou 310016, China
| | - Chao He
- Department of Colorectal Surgery, Sir Run Run Shaw Hospital, Zhejiang University, Hangzhou 310016, China.,Biomedical Research Center and Key Laboratory of Biotherapy of Zhejiang Province, Sir Run Run Shaw Hospital, Zhejiang University, Hangzhou 310016, China
| | - Xiaotong Hu
- Biomedical Research Center and Key Laboratory of Biotherapy of Zhejiang Province, Sir Run Run Shaw Hospital, Zhejiang University, Hangzhou 310016, China
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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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Sabokrouh A, Vaisi-Raygani A, Goodarzi MT, Khatami S, Taghizadeh-jahed M, Shahabadi N, Lakpour N, Shakiba Y. Comparison between Platinum-Azidothymidine and Azidothymidine Effects on Bcl-2 and Telomerase Gene Expression in Rats with Hepatocellular Carcinoma. Avicenna J Med Biotechnol 2015; 7:50-6. [PMID: 26140181 PMCID: PMC4483314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2014] [Accepted: 11/18/2014] [Indexed: 11/03/2022] Open
Abstract
BACKGROUND High expression of telomerase and Bcl-2 are reported in hepatocellular carcinoma. Some anticancer drugs show their effects through reduction of these factors. In this study, it was aimed to investigate the effects of a new synthetic compound, platinum azidothymidine, on inhibition of telomerase and Bcl-2 expression in hepatocellular carcinoma compared to azidothymidine. METHODS To study the effects of Pt-AZT on hepatocellular carcinoma and compare its effects with AZT in inhibition of telomerase and Bcl-2 gene expression, pathogen-free male Wistar rats (n=100) were used. They were randomly divided to 4 groups (n=25). Group A as the control group contained 25 healthy rats; in the rest of animals, preneoplastic lesions were induced in their livers (groups B, C, and D) using Solt-Farber resistant hepatocyte protocol. Cancer development was approved by a pathology laboratory. Group B was negative control (untreated), groups C and D were treated by intraperitoneal injection (IP) of Pt-AZT (0.9 mg/kg/day) and AZT (0.3 mg/kg/day), respectively for 14 days. At the end of the protocol, all rats were sacrificed and Bcl-2 and telomerase gene expression was determined using real-time PCR. RESULTS No tumor in the livers was found in group A at any point of the study, but it was present in livers of all animals in B, C and D groups. Results showed that telomerase and Bcl-2 expression was significantly lower in group C compared with group B (0.473±0.231 vs. 5.137±5.08, p<0.001, for telomerase expression, and 0.41±0.276 vs. 7.25±11.6, p<0.001, for Bcl-2 expression) and also compared with group D (0.473±0.231 vs. 3.48±4.02, p<0.001, for telomerase expression, and 0.41±0.276 vs. 4.93±18, p<0.001, for Bcl-2 expression). CONCLUSION For the first time, it was demonstrated that Pt-AZT has more inhibitory effect on telomerase and Bcl-2 expression than AZT. It effectively inhibits the growth of liver tumor in rats by extending apoptosis.
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Affiliation(s)
- Abdolreza Sabokrouh
- Department of Clinical Biochemistry, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Asad Vaisi-Raygani
- Molecular Diagnostic Research Center, Kermanshah University of Medical Sciences, Kermanshah, Iran,Corresponding authors: Asad Vaisi-Raygani, Ph.D., Department of Clinical Biochemistry, School of Medicine, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Mohammad Taghi Goodarzi
- Department of Clinical Biochemistry, Hamadan University of Medical Sciences, Hamadan, Iran, Research Center for Molecular Medicine, Hamadan University of Medical Sciences, Hamadan, Iran,Mohammad Taghi Goodarzi, Ph.D., Research Center for Molecular Medicine, Hamadan University of Medical Sciences, Hamadan, Iran, Tel: +98 813 8380466, Fax: +98 813 8380208, E-mail:;
| | - Shohreh Khatami
- Department of Clinical Biochemistry, Pasteur Institute, Tehran, Iran
| | | | - Nahid Shahabadi
- Department of Chemistry, Razi University of Kermanshah, Kermanshah, Iran
| | - Niknam Lakpour
- Reproductive Biotechnology Research Center, Avicenna Research Institute, ACECR, Tehran, Iran
| | - Yadollah Shakiba
- Molecular Diagnostic Research Center, Kermanshah University of Medical Sciences, Kermanshah, Iran
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Piwowar M, Dygut J, Piwowar P, Konieczny L, Roterman I. Attempt at a systemic outlook on aging and carcinogenesis. BIO-ALGORITHMS AND MED-SYSTEMS 2014. [DOI: 10.1515/bams-2014-0012] [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]
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Queisser A, Heeg S, Thaler M, von Werder A, Opitz OG. Inhibition of telomerase induces alternative lengthening of telomeres during human esophageal carcinogenesis. Cancer Genet 2013; 206:374-86. [DOI: 10.1016/j.cancergen.2013.10.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2013] [Revised: 09/25/2013] [Accepted: 10/02/2013] [Indexed: 12/28/2022]
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Akhtar N, Anand V, Verma KK, Sharma A. Augmented telomerase activity and reduced telomere length in parthenium-induced contact dermatitis. J Eur Acad Dermatol Venereol 2012; 27:1222-7. [PMID: 22946492 DOI: 10.1111/j.1468-3083.2012.04691.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND Parthenium dermatitis is a common chronic inflammatory disease with activated T lymphocytes that recognize the antigens, which leads to proliferation and differentiation. Telomeres and telomerase play an important role in the regulation of life span of the cell. Telomere length maintained by telomerase, are specialized repeats present at the end of chromosomes which protect it from degradation, end-to-end fusion and are important for integrity of chromosomes. OBJECTIVES The aim of this study was to measure telomerase activity and telomere length in Peripheral blood mononuclear cell (PBMC), CD4(+) and CD8(+) T lymphocytes from parthenium dermatitis patients. METHODS The study includes 50 patients of parthenium dermatitis confirmed by patch testing and 50 healthy controls. Telomerase activity was measured using the telomere repeat amplification protocol using PCR-ELISA kit. Telomere length was measured by using Telo TAGGG Telomere Length Assay Kit. RESULTS Significantly elevated levels of telomerase activity was observed in PBMC, CD4(+) and CD8(+) T cells of parthenium dermatitis patients as compared with healthy controls. However, significantly reduced telomere length in PBMC, CD4(+) and CD8(+) T cells have been found in patients than healthy subjects, but there was no difference between CD4(+) and CD8(+) T cells in patients. CONCLUSION This study might have provided insight into the role of telomerase in parthenium dermatitis that is characterized by the recruitment of T lymphocytes, which play an important role in this inflammatory disease. The augmented telomerase activity and reduced terminal restriction fragment length might be explored as a potential diagnostic/prognostic marker for parthenium dermatitis in future.
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Affiliation(s)
- N Akhtar
- Department of Biochemistry Department of Dermatology, All India Institute of Medical Sciences, New Delhi, India
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Mannoor K, Liao J, Jiang F. Small nucleolar RNAs in cancer. BIOCHIMICA ET BIOPHYSICA ACTA 2012; 1826:121-8. [PMID: 22498252 PMCID: PMC3842010 DOI: 10.1016/j.bbcan.2012.03.005] [Citation(s) in RCA: 96] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2012] [Revised: 03/19/2012] [Accepted: 03/20/2012] [Indexed: 12/16/2022]
Abstract
Non-coding RNAs (ncRNAs) are important regulatory molecules involved in various physiological and cellular processes. Alterations of ncRNAs, particularly microRNAs, play crucial roles in tumorigenesis. Accumulating evidence indicates that small nucleolar RNAs (snoRNAs), another large class of small ncRNAs, are gaining prominence and more actively involved in carcinogenesis than previously thought. Some snoRNAs exhibit differential expression patterns in a variety of human cancers and demonstrate capability to affect cell transformation, tumorigenesis, and metastasis. We are beginning to comprehend the functional repercussions of snoRNAs in the development and progression of malignancy. In this review, we will describe current studies that have shed new light on the functions of snoRNAs in carcinogenesis and the potential applications for cancer diagnosis and therapy.
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Affiliation(s)
- Kaiissar Mannoor
- Department of Pathology, University of Maryland School of Medicine, 10 S, Pine St, Baltimore, MD 21201, USA
| | - Jipei Liao
- Department of Pathology, University of Maryland School of Medicine, 10 S, Pine St, Baltimore, MD 21201, USA
| | - Feng Jiang
- Department of Pathology, University of Maryland School of Medicine, 10 S, Pine St, Baltimore, MD 21201, USA
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Matsuo T, Shimose S, Kubo T, Fujimori J, Yasunaga Y, Sugita T, Ochi M. Correlation between p38 mitogen-activated protein kinase and human telomerase reverse transcriptase in sarcomas. J Exp Clin Cancer Res 2012; 31:5. [PMID: 22243975 PMCID: PMC3296589 DOI: 10.1186/1756-9966-31-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2011] [Accepted: 01/16/2012] [Indexed: 11/27/2022] Open
Abstract
Background One of the major components of telomerase is the human telomerase reverse transcriptase (hTERT) as the catalytic protein. hTERT mRNA expression are reported to be associated with prognosis and tumor progression in several sarcomas. However, there is no clear understanding of the mechanisms of hTERT in human sarcomas. Recent studies have suggested that signals transmitted through p38 mitogen-activated protein kinase (MAPK) can increase or decrease hTERT transcription in human cells. The purpose of this study was to analyse the correlation between p38 MAPK and hTERT in sarcoma samples. Methods We investigated 36 soft tissue malignant fibrous histiocytomas (MFH), 24 liposarcomas (LS) and 9 bone MFH samples for hTERT and p38 MAPK expression. Quantitative detection of hTERT and p38 MAPK was performed by RT-PCR. Results There was a significant positive correlation between the values of hTERT and p38 MAPK in all samples (r = 0.445, p = 0.0001), soft tissue MFH (r = 0.352, p = 0.0352), LS (r = 0.704, p = 0.0001) and bone MFH samples (r = 0.802, p = 0.0093). Patients who had a higher than average expression of p38 MAPK had a significantly worse prognosis than other patients (p = 0.0036). Conclusions p38 MAPK may play a role in up-regulation of hTERT, and therefore, p38 MAPK may be a useful marker in the assessment of hTERT and patients' prognosis in sarcomas.
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Affiliation(s)
- Toshihiro Matsuo
- Department of Orthopaedic Surgery, National Hospital Organization Kure Medical Center and Chugoku Cancer Center: 3-1, Aoyamacho, Kure, Hiroshima, 7370023 Japan.
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Fujimori J, Matsuo T, Shimose S, Kubo T, Ishikawa M, Yasunaga Y, Ochi M. Antitumor effects of telomerase inhibitor TMPyP4 in osteosarcoma cell lines. J Orthop Res 2011; 29:1707-11. [PMID: 21590716 DOI: 10.1002/jor.21451] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2010] [Accepted: 04/20/2011] [Indexed: 02/04/2023]
Abstract
Telomere studies in carcinomas have been extensively reported for prognostic utility and effective methods for targeting telomerase therapy has been described, but efficacy of telomerase inhibitor remained unknown in sarcoma cells. In this study, we investigated the effects of telomerase inhibitor cationic porphyrin TMPyP4 on telomerase activity, telomere length, cell growth, and apoptosis in osteosarcoma cell lines. TMPyP4 significantly inhibited telomerase activity in telomerase positive HOS and Saos-2, but not in MG-63. TMPyP4 significantly induced telomere shortening, and inhibition of the cell growth in HOS and Saos-2 with over 17% apoptosis rates. In terms of MG-63, TMPyP4 did not induce inhibition of both telomerase activity and cell growth, although it induced significant telomere shortening. Telomere length after treatment was 5.60 kb in HOS, 4.00 kb in Saos-2, and 9.89 kb in MG-63. These results may suggest that both telomerase activity loss and sufficient telomere shortening are necessary to inhibit cell growth in telomerase positive osteosarcoma cells. TMPyP4 did not induced telomere shortening but significantly inhibited the growth with 22.6% apoptosis rate in telomerase negative with extremely longer telomere-U2OS, may indicating the antitumor effect of TMPyP4 may be related to DNA damage including telomere dysfunction through G-quadruplex stabilization, independent on telomere length.
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Affiliation(s)
- Jun Fujimori
- Department of Orthopaedic Surgery, Graduate School of Biomedical Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan.
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Kheirollahi M, Mehrazin M, Kamalian N, Mehdipour P. Alterations of telomere length in human brain tumors. Med Oncol 2011; 28:864-870. [PMID: 20373057 DOI: 10.1007/s12032-010-9506-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2010] [Accepted: 03/17/2010] [Indexed: 02/08/2023]
Abstract
Telomeres at the ends of human chromosomes consist of tandem hexametric (TTAGGG)n repeats, which protect them from degradation. At each cycle of cell division, most normal somatic cells lose approximately 50-100 bp of the terminal telomeric repeat DNA. Precise prediction of growth and estimation of the malignant potential of brain tumors require additional markers. DNA extraction was performed from the 51 frozen tissues, and a non-radioactive chemiluminescent assay was used for Southern blotting. One sample t-test shows highly significant difference in telomere length in meningioma and astrocytoma with normal range. According to our results, higher grades of meningioma and astrocytoma tumors show more heterogeneity in telomere length, and also it seems shortening process of telomeres is an early event in brain tumors.
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Affiliation(s)
- Majid Kheirollahi
- Department of Medical Genetics, School of Medicine, Tehran University of Medical Sciences, and Shariati Hospital, Tehran, Iran.
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Daneshvar K, Khan A, Goodliffe JM. Myc localizes to histone locus bodies during replication in Drosophila. PLoS One 2011; 6:e23928. [PMID: 21886841 PMCID: PMC3160328 DOI: 10.1371/journal.pone.0023928] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2011] [Accepted: 07/28/2011] [Indexed: 11/21/2022] Open
Abstract
Myc is an important protein at the center of multiple pathways required for growth and proliferation in animals. The absence of Myc is lethal in flies and mice, and its over-production is a potent inducer of over-proliferation and cancer. Myc protein is localized to the nucleus where it executes its many functions, however the specific sub-nuclear localization of Myc has rarely been reported. The work we describe here began with an observation of unexpected, punctate spots of Myc protein in certain regions of Drosophila embryos. We investigated the identity of these puncta and demonstrate that Myc is co-localized with coilin, a marker for sub-nuclear organelles known as Cajal Bodies (CBs), in embryos, larvae and ovaries. Using antibodies specific for U7 snRNP component Lsm11, we show that the majority of Myc and coilin co-localization occurs in Histone Locus Bodies (HLBs), the sites of histone mRNA transcription and processing. Furthermore, Myc localizes to HLBs only during replication in mitotic and endocycling cells, suggesting that its role there relates to replication-dependent canonical histone gene transcription. These results provide evidence that sub-nuclear localization of Myc is cell-cycle dependent and potentially important for histone mRNA production and processing.
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Affiliation(s)
- Kaveh Daneshvar
- Department of Biology, University of North Carolina at Charlotte, Charlotte, North Carolina, United States of America
| | - Abid Khan
- Department of Biology, University of North Carolina at Charlotte, Charlotte, North Carolina, United States of America
| | - Julie M. Goodliffe
- Department of Biology, University of North Carolina at Charlotte, Charlotte, North Carolina, United States of America
- * E-mail:
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Lobetti-Bodoni C, Bernocco E, Genuardi E, Boccadoro M, Ladetto M. Telomeres and telomerase in normal and malignant B-cells. Hematol Oncol 2011; 28:157-67. [PMID: 20213664 DOI: 10.1002/hon.937] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The telomeric checkpoint is emerging as a critical sensor of cellular damage, playing a major role in human aging and cancer development. In the meantime, telomere biology is rapidly evolving from a basic discipline to a translational branch, capable of providing major hints for biomarker development, risk assessment and targeted treatment of cancer. These advances have a number of implications in the biology of lymphoid tumours. Moreover, there is considerable interest in the potential role of telomeric dysfunction in the wide array of immunological abnormalities, grouped under the definition of 'immunosenescence'. This review will summarize the impact of recent advances in telomere biology on the physiology and pathology of the B lymphocyte, with special interest in immunosenescence and lymphomagenesis.
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Affiliation(s)
- Chiara Lobetti-Bodoni
- Department of Experimental Oncology, Division of Hematology, University of Torino, Italy
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Song JS, Jung SH, Yi SY, Oh HE, Cho MY, Park KH. Telomerase Activity in Urethane-Induced Mouse Lung Tumorigenesis. KOREAN JOURNAL OF PATHOLOGY 2011. [DOI: 10.4132/koreanjpathol.2011.45.3.261] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- Ji-Sun Song
- Department of Pathology, Kwandong University College of Medicine, Goyang, Korea
| | - Soon-Hee Jung
- Department of Pathology, Yonsei University Wonju College of Medicine, Wonju, Korea
| | - Sang Yeop Yi
- Department of Pathology, Kwandong University College of Medicine, Goyang, Korea
| | - Hwa Eun Oh
- Department of Pathology, Kwandong University College of Medicine, Goyang, Korea
| | - Mee Yon Cho
- Department of Pathology, Yonsei University Wonju College of Medicine, Wonju, Korea
| | - Kwang Hwa Park
- Department of Pathology, Yonsei University Wonju College of Medicine, Wonju, Korea
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Kryukov F, Ocadlíková D, Kovárová L, Buresová I, Hájek R, Michálek J. In vitro activation of cytotoxic T-lymphocytes by hTERT-pulsed dendritic cells. J Immunotoxicol 2010; 6:243-8. [PMID: 19908943 DOI: 10.3109/15476910903236134] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Multiple myeloma has been considered a weakly immunogenic malignancy that can cause profound defects in the immune system. An important issue for the immunotherapy of myeloma is the identification of appropriate tumor-associated antigens (TAAs). Recently, hTERT (human telomerase reverse transcriptase) was detected on a majority of human malignancies. In the studies reported here, we studied antigen-specific and HLA-A2-restricted cytotoxic activity against an ARH77 myeloma cell line in vitro. An HLA-A2-specific hTERT-derived nonapeptide ((540)ILAKFLHWL(548)) was used as a TAA. Myeloma-specific cytotoxic activity of hTERT-reactive cytotoxic lymphocytes (CTLs) was established by repeated stimulation of the CTLs via dendritic cells loaded with hTERT-derived nonapeptide. These studies were able to demonstrate that hTERT-reactive T-lymphocytes can be identified and expanded using relatively simple in vitro techniques consisting of antigen-specific stimulation, immunomagnetic sorting, and then induction of rapid expansion.
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Affiliation(s)
- Fedor Kryukov
- University Cell Immunotherapy Center, Masaryk University, Brno, Czech Republic.
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Nakano M, Kakiuchi Y, Shimada Y, Ohyama M, Ogiwara Y, Sasaki-Higashiyama N, Yano N, Ikeda F, Yamada E, Iwamatsu A, Kobayashi K, Nishiyama K, Ichikawa S, Kaji K, Ide T, Murofushi H, Murakami-Murofushi K. MOV10 as a novel telomerase-associated protein. Biochem Biophys Res Commun 2009; 388:328-32. [DOI: 10.1016/j.bbrc.2009.08.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2009] [Accepted: 08/03/2009] [Indexed: 12/01/2022]
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Zambre VP, Murumkar PR, Giridhar R, Yadav MR. Structural Investigations of Acridine Derivatives by CoMFA and CoMSIA Reveal Novel Insight into Their Structures toward DNA G-Quadruplex Mediated Telomerase Inhibition and Offer a Highly Predictive 3D-Model for Substituted Acridines. J Chem Inf Model 2009; 49:1298-311. [DOI: 10.1021/ci900036w] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Vishal P. Zambre
- Pharmacy Department, Faculty of Technology and Engineering, Kalabhavan, The M.S. University of Baroda, Vadodara - 390001, Gujarat, India
| | - Prashant R. Murumkar
- Pharmacy Department, Faculty of Technology and Engineering, Kalabhavan, The M.S. University of Baroda, Vadodara - 390001, Gujarat, India
| | - Rajani Giridhar
- Pharmacy Department, Faculty of Technology and Engineering, Kalabhavan, The M.S. University of Baroda, Vadodara - 390001, Gujarat, India
| | - Mange Ram Yadav
- Pharmacy Department, Faculty of Technology and Engineering, Kalabhavan, The M.S. University of Baroda, Vadodara - 390001, Gujarat, India
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Deville L, Hillion J, Ségal-Bendirdjian E. Telomerase regulation in hematological cancers: a matter of stemness? Biochim Biophys Acta Mol Basis Dis 2009; 1792:229-39. [PMID: 19419697 DOI: 10.1016/j.bbadis.2009.01.016] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2008] [Revised: 01/30/2009] [Accepted: 01/30/2009] [Indexed: 01/02/2023]
Abstract
Human telomerase is a nuclear ribonucleoprotein enzyme complex that catalyzes the synthesis and extension of telomeric DNA. This enzyme is highly expressed and active in most malignant tumors while it is usually not or transiently detectable in normal somatic cells, suggesting that it plays an important role in cellular immortalization and tumorigenesis. As most leukemic cells are generally telomerase-positive and have often shortened telomeres, our understanding of how telomerase is deregulated in these diseases could help to define novel therapies targeting the telomere/telomerase complex. Nonetheless, considering that normal hematopoietic stem cells and some of their progeny do express a functional telomerase, it is tempting to consider such an activity in leukemias as a sustained stemness feature and important to understand how telomere length and telomerase activity are regulated in the various forms of leukemias.
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Affiliation(s)
- Laure Deville
- INSERM UMR-S 685, Institut d'Hématologie, Hôpital Saint-Louis, 75475 Paris cedex 10, France
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Wong CH, Chan SKP, Chan HLY, Tsui SKW, Feitelson M. The Molecular Diagnosis of Hepatitis B Virus-Associated Hepatocellular Carcinoma. Crit Rev Clin Lab Sci 2008; 43:69-101. [PMID: 16531275 DOI: 10.1080/10408360500410407] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Hepatitis B virus (HBV) infection is the major cause of hepatocellular carcinoma (HCC) worldwide. The pathogenesis of HBV-associated HCC has been studied extensively, and molecular changes during malignant transformation have been identified. It has been proposed that the insertion of HBV DNA into the human genome results in chromosomal instability and inactivation of tumor suppressor genes. Transactivation of oncogenes, inactivation of tumor suppressor genes, and alteration of the cell cycle by HBV proteins are also involved in the progression of hepatocellular carcinogenesis. Traditional clinical examinations of HCC, such as biopsy, computer tomography, ultrasonic imaging, and detection of such biomarkers as a-fetoprotein, are currently the "gold standard" in diagnosis. These tests diagnose HCC only in the late stages of disease. This limitation has greatly reduced the chance of survival of HCC patients. To resolve this problem, new biomarkers that can diagnose HCC in earlier stages are necessary. Based on recent molecular studies of the effects of HBV on cellular transformation, differentially expressed biomarkers of HBV infection have been elucidated. With the analyses of the HBV replication profile, the viral load (HBV DNA levels) of patients, and the viral protein expression, the severity of hepatitis in the preneoplastic stages can be assessed. In the future, with the molecular profiles identified by genomic and proteomic approaches, stage-specific biomarkers should be identified to monitor the progression and prognosis of HCC.
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Affiliation(s)
- Chi-Hang Wong
- Center for Emerging Infectious Diseases, The Chinese University, Hong Kong, Shatin, N.T., Hong Kong SAR, China
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Weber GF. Molecular mechanisms of metastasis. Cancer Lett 2008; 270:181-90. [PMID: 18522865 DOI: 10.1016/j.canlet.2008.04.030] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2008] [Revised: 04/11/2008] [Accepted: 04/14/2008] [Indexed: 11/26/2022]
Abstract
Metastasis formation is an essential aspect of cancer, for which the molecular underpinning has long been subject to debate. Although the organ preference for dissemination is governed by tumor-host interactions on the epigenetic level there is a genetic basis to the ability of cancer cells to disseminate. Metastasis genes encode homing receptors, their ligands, and extracellular matrix-degrading proteinases, which jointly cause invasion and anchorage-independence. They are developmentally non-essential stress response genes that physiologically mediate the homing of immune system cells. Metastatic potential is conferred to cancer cells by aberrant expression or splicing of these genes. Oncogenes act upstream of metastasis genes. In cancer cells, oncogenic signaling activates distinct genetic programs leading to cell cycle progression and invasiveness, respectively. The expression of metastasis genes is regulated by multi-subunit transcription factor complexes. The identification of genes that direct cancer metastasis implicates them as candidate drug targets.
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Affiliation(s)
- Georg F Weber
- University of Cincinnati Academic Health Center, College of Pharmacy, 3225 Eden Avenue, Cincinnati, OH 45267-0004, USA.
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Telomere stability and telomerase in mesenchymal stem cells. Biochimie 2008; 90:33-40. [DOI: 10.1016/j.biochi.2007.09.005] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2007] [Accepted: 09/10/2007] [Indexed: 01/25/2023]
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Patel DJ, Phan AT, Kuryavyi V. Human telomere, oncogenic promoter and 5'-UTR G-quadruplexes: diverse higher order DNA and RNA targets for cancer therapeutics. Nucleic Acids Res 2007; 35:7429-55. [PMID: 17913750 PMCID: PMC2190718 DOI: 10.1093/nar/gkm711] [Citation(s) in RCA: 751] [Impact Index Per Article: 41.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Guanine-rich DNA sequences can form G-quadruplexes stabilized by stacked G–G–G–G tetrads in monovalent cation-containing solution. The length and number of individual G-tracts and the length and sequence context of linker residues define the diverse topologies adopted by G-quadruplexes. The review highlights recent solution NMR-based G-quadruplex structures formed by the four-repeat human telomere in K+ solution and the guanine-rich strands of c-myc, c-kit and variant bcl-2 oncogenic promoters, as well as a bimolecular G-quadruplex that targets HIV-1 integrase. Such structure determinations have helped to identify unanticipated scaffolds such as interlocked G-quadruplexes, as well as novel topologies represented by double-chain-reversal and V-shaped loops, triads, mixed tetrads, adenine-mediated pentads and hexads and snap-back G-tetrad alignments. The review also highlights the recent identification of guanine-rich sequences positioned adjacent to translation start sites in 5′-untranslated regions (5′-UTRs) of RNA oncogenic sequences. The activity of the enzyme telomerase, which maintains telomere length, can be negatively regulated through G-quadruplex formation at telomeric ends. The review evaluates progress related to ongoing efforts to identify small molecule drugs that bind and stabilize distinct G-quadruplex scaffolds associated with telomeric and oncogenic sequences, and outlines progress towards identifying recognition principles based on several X-ray-based structures of ligand–G-quadruplex complexes.
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Affiliation(s)
- Dinshaw J Patel
- Structural Biology Program, Memorial Sloan-Kettering Cancer Center, New York, NY 10021, USA.
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Nakamura KI, Takubo K, Izumiyama-Shimomura N, Sawabe M, Arai T, Kishimoto H, Fujiwara M, Kato M, Oshimura M, Ishii A, Ishikawa N. Telomeric DNA length in cerebral gray and white matter is associated with longevity in individuals aged 70 years or older. Exp Gerontol 2007; 42:944-50. [PMID: 17606349 DOI: 10.1016/j.exger.2007.05.003] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2006] [Revised: 05/08/2007] [Accepted: 05/08/2007] [Indexed: 11/29/2022]
Abstract
Many studies have demonstrated the association between telomere length in mitotic cells and carcinogenesis and mortality, but little attention has been focused on post-mitotic cells and human life expectancy. We assessed the relationship between telomere length in cerebral gray and white matter and longevity in 72 autopsied Japanese patients aged 0-100 years using Southern blot hybridization. The mean telomere lengths in the gray and white matter were 12.3+/-2.5 kilobase pairs and 11.4+/-2.1 kilobase pairs, respectively. The mean telomere lengths in 60-69 year decadal group were less than those of neonates, and declined further in the 70-79-year age group, but those in groups of further advanced age were longer than in the 70-79 year group (70-79<80-89<90-100 years of age). Thus, the 90-100-year age group possessed significantly longer telomeres than the 70s (p=0.029). Autopsy protocols showed a decrease in the rate of cancer death in individuals in their 80s (p=0.041) and 90s (p=0.017) versus those in their 60s, and in their 80s the mean telomere length in the gray matter from cancer death patients was significantly shorter than that of patients who died of other diseases (p=0.04). These data suggest that innate telomere lengths are maintained very well in the cerebrum, and are associated with longevity. Our study lends indispensable support to the hypothesis that longer telomeres protect the genome from instability (a major cause of carcinogenesis) and are beneficial for longevity.
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Affiliation(s)
- Ken-Ichi Nakamura
- Research Team for Geriatric Diseases, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan
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Matsuo T, Hiyama E, Sugita T, Shimose S, Kubo T, Mochizuki Y, Adachi N, Kojima K, Sharman P, Ochi M. Telomerase Activity in Giant Cell Tumors of Bone. Ann Surg Oncol 2007; 14:2896-902. [PMID: 17653593 DOI: 10.1245/s10434-007-9391-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2005] [Accepted: 01/04/2006] [Indexed: 11/18/2022]
Abstract
BACKGROUND A giant cell tumor of bone (GCT) is a histologically benign neoplasma that has an unpredictable pattern of biological aggressiveness. In the present study, we investigated whether there was a correlation between telomere length or the levels of telomerase activity and other clinical features of GCTs, for the possible use of these factors as parameters of aggressiveness or prognosis. METHODS In 16 surgically resected GCTs specimens, telomere length was assessed by terminal restriction fragments by Southern blot analysis. Telomerase activity was measured by a semiquantitative polymerase chain reaction-based telomeric repeat amplification protocol assay. RESULTS Telomere length reduction was observed in 69% of the GCT samples. The telomere lengths of tumors were significantly shorter than those of normal tissue (P = .008). The mean telomere length of grade 3 tumors was significantly shorter than those of grade 1 and 2 tumors (P = .038). Telomerase activity was detected in 81% of tumor samples. The level of telomerase activity in tumors with local recurrence was significantly higher than in tumors without local recurrence (P = .011). CONCLUSIONS These results suggest that telomere length correlates with roentgenographic grade as a result of the frequency of cell division, and high telomerase activity indicates the aggressiveness of GCTs.
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Affiliation(s)
- Toshihiro Matsuo
- Department of Orthopaedic Surgery, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8551, Japan.
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Aoki H, Iwado E, Eller MS, Kondo Y, Fujiwara K, Li GZ, Hess KR, Siwak DR, Sawaya R, Mills GB, Gilchrest BA, Kondo S. Telomere 3' overhang-specific DNA oligonucleotides induce autophagy in malignant glioma cells. FASEB J 2007; 21:2918-30. [PMID: 17449721 DOI: 10.1096/fj.06-6941com] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Telomere 3' overhang-specific DNA oligonucleotides (T-oligos) induce cell death in cancer cells, presumably by mimicking telomere loop disruption. Therefore, T-oligos are considered an exciting new therapeutic strategy. The purpose of this study was to elucidate how T-oligos exert antitumor effects on human malignant glioma cells in vitro and in vivo. We demonstrated that T-oligos inhibited the proliferation of malignant glioma cells through induction of nonapoptotic cell death and mitochondria hyperpolarization, whereas normal astrocytes were resistant to T-oligos. Tumor cells treated with T-oligos developed features compatible with autophagy, with development of autophagic vacuoles and conversion of an autophagy-related protein, microtubule-associated protein 1 light chain 3 from type I (cytoplasmic form) to type II (membrane form of autophagic vacuoles). A reverse-phase protein microarray analysis and Western blotting revealed that treatment with T-oligos inhibited the mammalian target of the rapamycin (mTOR) and the signal transducer and activator of transcription 3 (STAT3). Moreover, pretreatment with T-oligos significantly prolonged the survival time of mice inoculated intracranially with malignant glioma cells compared with that of untreated mice and those treated with control oligonucleotides (P=0.0065 and P=0.043, respectively). These results indicate that T-oligos stimulate the induction of nonapoptotic autophagic also known as type II programmed cell death and are thus promising in the treatment of malignant glioma.
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Affiliation(s)
- Hiroshi Aoki
- Department of Neurosurgery, The University of Texas M. D. Anderson Cancer Center, 1515 Holcombe Blvd., Houston, TX 77030, USA
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Mondello C, Bottone MG, Noriki S, Soldani C, Pellicciari C, Scovassi AI. Oxidative stress response in telomerase-immortalized fibroblasts from a centenarian. Ann N Y Acad Sci 2007; 1091:94-101. [PMID: 17341606 DOI: 10.1196/annals.1378.058] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
It has been reported that cells with ectopic expression of telomerase are more resistant to apoptotic cell death than their normal counterpart. However, controversial results were obtained when the cellular response to oxidative stress was analyzed. The present research was therefore aimed at defining the effect of the oxidative stress induced by tert-butylhydroperoxide (tBOOH) and 2-deoxy-D-ribose (D-ribose) in human fibroblasts from a centenarian (cen3) and, in parallel, on the same cells after telomerase immortalization (cen3tel cells). By studying different parameters of apoptosis in situ (i.e., chromatin condensation, phosphatidylserine externalization, and DNA fragmentation), we found that both tBOOH and D-ribose induce apoptosis to a greater extent in cen3 than in cen3tel cells, suggesting a protective role of telomerase toward apoptotic death. However, monitoring the cell number during treatment with the drugs, we found a decrease in cell number; since this reduction was lower in cen3 fibroblasts compared to cen3tel cells, it is likely that telomerase does not fully protect cells from drug toxicity.
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Affiliation(s)
- Chiara Mondello
- Istituto di Genetica Molecolare del CNR, Via Abbiategrasso 207, 27100 Pavia, Italy.
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Cortez-Gonzalez X, Zanetti M. Telomerase immunity from bench to bedside: round one. J Transl Med 2007; 5:12. [PMID: 17324292 PMCID: PMC1839079 DOI: 10.1186/1479-5876-5-12] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2006] [Accepted: 02/26/2007] [Indexed: 11/10/2022] Open
Abstract
Telomerase, a reverse transcriptase primarily devoted to the elongation of telomeres in mammalian cells, is also the first bona fide common tumor antigen. In fact, telomerase is over-expressed in > 85% of tumor cells irrespective of origin and histological type. In the past seven years, there has been considerable interest in assessing telomerase as substrate for vaccination in cancer patients to induce CD8 T cell responses. Because the activation of T cells is restricted by the MHC molecules on antigen presenting cells or tumor cells, the identification of telomerase peptides immunogenic for humans is tightly linked with HLA types. To date, a handful of peptides have been identified through a variety of screening procedures, including bioinformatics prediction, in vivo immunization of HLA transgenic mice, in vitro immunization of PBMC from normal donors and cancer patients, and processing in human tumor cells. Currently, there exist putative peptides for five major HLA types (A2, A1, A3, A24 and B7). Due to the complexity of the HLA system, trials have been performed focusing on the most prevalent HLA type, HLA-A2. Here, we summarize this collective effort and highlight results obtained in Phase 1 trials including a Phase 1 trial performed at the UCSD Cancer Center.
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Affiliation(s)
- Xochtil Cortez-Gonzalez
- The Laboratory of Immunology, Department of Medicine and Moores Cancer Center, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0837, USA.
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Wuebbles R, Jones PL. Engineered telomeres in transgenic Xenopus laevis. Transgenic Res 2007; 16:377-84. [PMID: 17447124 DOI: 10.1007/s11248-007-9076-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2006] [Accepted: 01/24/2007] [Indexed: 12/13/2022]
Abstract
The expanding roles of telomeres in epigenetic gene regulation, nuclear organization, and human disease have necessitated the establishment of model organisms in which to study telomere function under normal developmental conditions. We present an efficient system for generating numerous vertebrate animals containing engineered telomeres using a Xenopus laevis transgenesis technique. Our results indicate Xenopus zygotes efficiently recognize telomeric repeats at chromosome break points and form telomeric complexes thus generating a new telomere. The resulting transgenic animals progress through normal development and successfully metamorphose into froglets despite the chromosome breakage. Overall, this presents an efficient mechanism for generating engineered telomeres in a vertebrate system and provides an opportunity to investigate epigenetic aspects of telomere function during normal vertebrate development.
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Affiliation(s)
- Ryan Wuebbles
- B107 Chemical and Life Sciences Laboratory, Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
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Qi H, Lin CP, Fu X, Wood LM, Liu AA, Tsai YC, Chen Y, Barbieri CM, Pilch DS, Liu LF. G-quadruplexes induce apoptosis in tumor cells. Cancer Res 2007; 66:11808-16. [PMID: 17178877 DOI: 10.1158/0008-5472.can-06-1225] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Several G-rich oligodeoxynucleotides (ODNs), which are capable of forming G-quadruplexes, have been shown to exhibit antiproliferative activity against tumor cell lines and antitumor activity in nude mice carrying prostate and breast tumor xenografts. However, the molecular basis for their antitumor activity remains unclear. In the current study, we showed that a variety of telomeric G-tail oligodeoxynucleotides (TG-ODNs) exhibited antiproliferative activity against many tumor cells in culture. Systematic mutational analysis of the TG-ODNs suggests that the antiproliferative activity depends on the G-quadruplex conformation of these TG-ODNs. TG-ODNs were also shown to induce poly(ADP-ribose) polymerase-1 cleavage, phosphatidylserine flipping, and caspase activation, indicative of induction of apoptosis. TG-ODN-induced apoptosis was largely ataxia telangiectasia mutated (ATM) dependent. Furthermore, TG-ODN-induced apoptosis was inhibited by the c-Jun NH(2)-terminal kinase (JNK) inhibitor SP600125. Indeed, TG-ODNs were shown to activate the JNK pathway in an ATM-dependent manner as evidenced by elevated phosphorylation of JNK and c-Jun. Interestingly, a number of G-quadruplex ODNs (GQ-ODN) derived from nontelomeric sequences also induced ATM/JNK-dependent apoptosis, suggesting a possible common mechanism of tumor cell killing by GQ-ODNs.
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Affiliation(s)
- Haiyan Qi
- Department of Pharmacology, University of Medicine and Dentistry of New Jersey, Robert Wood Johnson Medical School, Piscataway, New Jersey 08854, USA.
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Canales BK, Li Y, Thompson MG, Gleason JM, Chen Z, Malaeb B, Corey DR, Herbert BS, Shay JW, Koeneman KS. Small molecule, oligonucleotide-based telomerase template inhibition in combination with cytolytic therapy in an in vitro androgen-independent prostate cancer model. Urol Oncol 2006; 24:141-51. [PMID: 16520278 DOI: 10.1016/j.urolonc.2005.11.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
PURPOSE Determine the efficacy and timing of small molecule oligonucleotide-based inhibitors to the enzyme telomerase in an in vitro model of androgen-independent, osseous prostate cancer. MATERIALS AND METHODS Telomerase was inhibited in prostate cancer cell lines C4-2/C4-2B and in controls by using small molecule antisense oligonucleotide-based inhibitors alone or in various combinations of small-dose Taxotere (sanofi-aventis, Bridgewater, NJ) and/or conditionally replication competent adenovirus (AD-BSP-E1a). After transfection and proliferation, telomerase telomeric repeat amplification protocol and telomere restriction fragment assays were performed, with specific times for evaluating telomere length. Specimens were stained for analysis with hematoxylin and eosin (H&E), terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labeling (TUNEL), and prostate-specific antigen (PSA). RESULTS C4-2/C4-2B cell lines had the shortest initial mean telomere length (approximately 2.5 kilobase [kb]) compared to PC-3 (approximately 5.5 kb). Dose-dependent inhibition of telomerase activity was seen using match oligonucleotide-based inhibitors to telomerase (50% inhibitory concentration 3-5 nm), whereas mismatch compound showed no telomerase inhibition. Significant growth delay and apoptosis in cell lines occurred after > 50 days of treatment. Cells treated with combination "triple therapy" (i.e., telomerase inhibitors, adenovirus, and Taxotere) had the highest amount of apoptosis. Compared to controls, all combination treatment groups had statistically significant reductions in prostate-specific antigen in the conditioned media. CONCLUSIONS Combining cytotoxic regimens with small molecule inhibitors to telomerase with oligonucleotide-based agents could be beneficial in controlling osseous hormone refractory prostate cancer, as evidenced by these in vitro, preclinical investigations. Telomerase inhibition needs to move into in vivo models and human studies.
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Affiliation(s)
- Benjamin K Canales
- Department of Urology, University of Minnesota, Minneapolis, MN 55455, USA
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Dreesen O, Cross GAM. Telomerase-independent stabilization of short telomeres in Trypanosoma brucei. Mol Cell Biol 2006; 26:4911-9. [PMID: 16782879 PMCID: PMC1489180 DOI: 10.1128/mcb.00212-06] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In cancer cells and germ cells, shortening of chromosome ends is prevented by telomerase. Telomerase-deficient cells have a replicative life span, after which they enter senescence. Senescent cells can give rise to survivors that maintain chromosome ends through recombination-based amplification of telomeric or subtelomeric repeats. We found that in Trypanosoma brucei, critically short telomeres are stable in the absence of telomerase. Telomere stabilization ensured genomic integrity and could have implications for telomere maintenance in human telomerase-deficient cells. Cloning and sequencing revealed 7 to 27 TTAGGG repeats on stabilized telomeres and no changes in the subtelomeric region. Clones with short telomeres were used to study telomere elongation dynamics, which differed dramatically at transcriptionally active and silent telomeres, after restoration of telomerase. We propose that transcription makes the termini of short telomeres accessible for rapid elongation by telomerase and that telomere elongation in T. brucei is not regulated by a protein-counting mechanism. Many minichromosomes were lost after long-term culture in the absence of telomerase, which may reflect their different mitotic segregation properties.
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Affiliation(s)
- Oliver Dreesen
- Laboratory of Molecular Parasitology, The Rockefeller University, 1230 York Avenue, New York, NY 10021, USA
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Zongaro S, de Stanchina E, Colombo T, D'Incalci M, Giulotto E, Mondello C. Stepwise neoplastic transformation of a telomerase immortalized fibroblast cell line. Cancer Res 2006; 65:11411-8. [PMID: 16357149 DOI: 10.1158/0008-5472.can-05-1140] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
We have described recently a human fibroblast cell line immortalized through ectopic telomerase expression (cen3tel), in which the extension of the life span was associated with the appearance of chromosomal aberrations and with the ability to grow in the absence of solid support. As reported in this article, on further propagation in culture, cen3tel cells became neoplastically transformed, being able to form tumors in nude mice. The analysis of the cells, during the gradual transition toward the tumorigenic phenotype, allowed us to trace cellular and molecular changes associated with different phases of transformation. At the stage in which they were able to grow in agar, cen3tel cells had lost contact growth inhibition but still retained the requirement of serum to proliferate and were not tumorigenic in immunocompromised mice. Moreover, they showed a down-regulation of the INK4A locus and were resistant to oncogenic Ras-induced senescence but still retained a functional p53. Subsequently, cen3tel cells became tumorigenic, lost p53 function because of a mutation in the DNA-binding motif, and overexpressed c-myc. Interestingly, tumorigenic cells did not carry activating mutations either in the ras proto-oncogenes (H-ras, N-ras, and K-ras) or in B-raf. Cen3tel cells gradually became hyperdiploid but did not display centrosome abnormalities. To our knowledge, cen3tel is the first telomerase immortalized fibroblast line, which became neoplastically transformed. In this system, we could associate a down-regulation of the INK4A locus with anchorage-independent growth and with resistance to Ras-induced senescence and link p53 mutations and c-myc overexpression with tumorigenicity.
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Affiliation(s)
- Samantha Zongaro
- Istituto di Genetica Molecolare, Consiglio Nazionale della Ricerche, Pavia, Italy
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Abstract
Telomerase adds telomeric repeats to the ends of telomeres to compensate for their progressive loss. A favorable prognosis is associated with low or no telomerase in some tumors. The authors investigated whether telomerase activity is associated with survival of patients with brain tumors. Sixty-two consecutive patients with brain tumors underwent surgery, and their surgical specimens were investigated. The patients were pathologically categorized as group I (aggressive group) and group II (non-aggressive group). Telomerase activity was examined by the telomeric repeat amplification protocol (TRAP) assay. The median time was calculated in association with overall survival and progression-free survival in each group. The significant difference was noted in telomerase activity between high-grade gliomas and lowgrade gliomas (p=0.022). Telomerase activity was significantly associated with the median overall survival and progression-free survival in all tumors of the aggressive group. On the other hand, the median overall survival in the non-aggressive group was not dependent on telomerase activity, while the median progression-free survival was. Our data suggests that telomerase is an important prognostic indicator of survival in patients with brain tumors.
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Affiliation(s)
- Choong Hyun Kim
- Department of Neurosurgery, Hanyang University College of Medicine, Seoul, Korea.
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Sanz-Casla MT, Vidaurreta M, Sanchez-Rueda D, Maestro ML, Arroyo M, Cerdán FJ. Telomerase activity as a prognostic factor in colorectal cancer. Oncol Res Treat 2006; 28:553-7. [PMID: 16249640 DOI: 10.1159/000088525] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2005] [Indexed: 01/22/2023]
Abstract
BACKGROUND As the enzyme telomerase extends the life of the cell through its ability to lengthen telomeres, its activity in different types of tumor has been evaluated as a possible factor involved in tumorigenesis. The aim of this study was to assess the prognostic significance of telomerase activity in patients with colorectal carcinoma. PATIENTS AND METHODS Telomerase activity was determined in 103 patients undergoing surgery for colorectal cancer between 2001 and 2003. Telomerase activity was determined by an enzyme-linked immunoassay based on the amplification of telomeric repeat sequences (TRAP assay). RESULTS 90% of our study population showed telomerase activity. Telomerase activity was related to tumor stage and site: a lower proportion of patients with stage A tumors showed telomerase activity compared to more advanced stages; and more patients with colon than with rectal carcinomas were telomerase positive. Multivariate analysis revealed that by adjusting for tumor stage, telomerase activity could be used to predict the risk of death or recurrence (p < 0.001). CONCLUSIONS Activation of telomerase seems to be a frequent event related to the stage of the tumor in colorectal tumorigenesis. Our findings suggest that telomerase activity can predict a greater risk of death or recurrence, irrespective of the more conventional prognostic factors.
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Dueñas-González A, Lizano M, Candelaria M, Cetina L, Arce C, Cervera E. Epigenetics of cervical cancer. An overview and therapeutic perspectives. Mol Cancer 2005; 4:38. [PMID: 16248899 PMCID: PMC1291396 DOI: 10.1186/1476-4598-4-38] [Citation(s) in RCA: 156] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2005] [Accepted: 10/25/2005] [Indexed: 12/22/2022] Open
Abstract
Cervical cancer remains one of the greatest killers of women worldwide. It is difficult to foresee a dramatic increase in cure rate even with the most optimal combination of cytotoxic drugs, surgery, and radiation; therefore, testing of molecular targeted therapies against this malignancy is highly desirable. A number of epigenetic alterations occur during all stages of cervical carcinogenesis in both human papillomavirus and host cellular genomes, which include global DNA hypomethylation, hypermetylation of key tumor suppressor genes, and histone modifications. The reversible nature of epigenetic changes constitutes a target for transcriptional therapies, namely DNA methylation and histone deacetylase inhibitors. To date, studies in patients with cervical cancer have demonstrated the feasibility of reactivating the expression of hypermethylated and silenced tumor suppressor genes as well as the hyperacetylating and inhibitory effect upon histone deacetylase activity in tumor tissues after treatment with demethylating and histone deacetylase inhibitors. In addition, detection of epigenetic changes in cytological smears, serum DNA, and peripheral blood are of potential interest for development of novel biomolecular markers for early detection, prediction of response, and prognosis.
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Affiliation(s)
- Alfonso Dueñas-González
- Unidad de Investigación Biomédica en Cáncer, Instituto Nacional de Cancerología/Instituto de Investigaciones Biomédicas (INCan/IIB), Universidad Nacional Autónoma de Mexico (UNAM), Mexico City. Mexico
| | - Marcela Lizano
- Unidad de Investigación Biomédica en Cáncer, Instituto Nacional de Cancerología/Instituto de Investigaciones Biomédicas (INCan/IIB), Universidad Nacional Autónoma de Mexico (UNAM), Mexico City. Mexico
| | - Myrna Candelaria
- Division of Clinical Research, Instituto Nacional de Cancerología (INCan), Mexico City, Mexico
| | - Lucely Cetina
- Division of Clinical Research, Instituto Nacional de Cancerología (INCan), Mexico City, Mexico
| | - Claudia Arce
- Division of Clinical Research, Instituto Nacional de Cancerología (INCan), Mexico City, Mexico
| | - Eduardo Cervera
- Division of Clinical Research, Instituto Nacional de Cancerología (INCan), Mexico City, Mexico
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Gagos S, Irminger-Finger I. Chromosome instability in neoplasia: chaotic roots to continuous growth. Int J Biochem Cell Biol 2005; 37:1014-33. [PMID: 15743675 DOI: 10.1016/j.biocel.2005.01.003] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2004] [Revised: 01/06/2005] [Accepted: 01/07/2005] [Indexed: 12/31/2022]
Abstract
Multiple rearrangements of chromosome number and structure are common manifestations of genomic instability encountered in mammalian tumors. In neoplasia, in continuous immortalized growth in vitro, and in animal models, the accumulation of various defects on DNA repair and telomere maintenance machineries, mitotic spindle abnormalities, and breakage-fusion-bridge cycles, deteriorate the precise mitotic distribution of the genomic content, thus producing various types of chromosomal anomalies. These lesions generate tremendous genomic imbalances, which are evolutionary selected, since they force the function of the whole genome towards continuous growth. For more than a century chromosomal rearrangements and aneuploidy in neoplasia have been discussed and a vast number of genes and pathways, directly or indirectly implicated, have been described. In this review, we focus on the biological mechanisms that generate numerical or structural deviations of the normal diploid chromosomal constitution in epithelial neoplasia. There is growing evidence that chromosomal instability is both an epiphenomenon and a leading cause of cancer. We will discuss the roles of genes, chromosome structure, and telomere dysfunction in the initiation of chromosomal instability. We will explore research strategies that can be applied to identify rates of chromosomal instability in a specimen, and the putative biological consequences of karyotypic heterogeneity. Finally, we will re-examine the longstanding hypothesis of the generation of aneuploidy in the context of telomere dysfunction and restoration.
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Affiliation(s)
- Sarantis Gagos
- Laboratory of Genetics, Foundation for Biomedical Research of the Academy of Athens Greece, Soranou Efessiou 4, Athens 11527, Greece.
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Dreesen O, Li B, Cross GAM. Telomere structure and shortening in telomerase-deficient Trypanosoma brucei. Nucleic Acids Res 2005; 33:4536-43. [PMID: 16091631 PMCID: PMC1184224 DOI: 10.1093/nar/gki769] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Telomerase consists of a reverse transcriptase (TERT) and an RNA that contains a template for telomere-repeat extension. Telomerase is required to prevent telomere erosion and its activity or lack thereof is important for tumorigenesis and ageing. Telomerase has been identified in numerous organisms but it has not been studied in kinetoplastid protozoa. Trypanosoma brucei, the causative agent of African sleeping sickness, evades the host immune response by frequently changing its variant surface glycoprotein (VSG). The single expressed VSG is transcribed from one of ∼20 subtelomeric ‘Expression Sites’, but the role telomeres might play in regulating VSG transcription and switching is unknown. We identified and sequenced the T.brucei TERT gene. Deleting TERT resulted in progressive telomere shortening of 3–6 bp per generation. In other organisms, the rate of telomere shortening is proportional to the length of the terminal 3′ single-strand overhang. In T.brucei, G-overhangs were undetectable (<30 nt) by in-gel hybridization. The rate of telomere shortening therefore, agrees with the predicted shortening due to the end replication problem, and is consistent with our observation that G-overhangs are short. Trypanosomes whose telomere length can be manipulated provide a new tool to investigate the role of telomeres in antigenic variation.
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Affiliation(s)
| | | | - George A. M. Cross
- To whom correspondence should be addressed. Tel: +1 212 327 7571; Fax: +1 212 3277845;
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Leeper TC, Varani G. The structure of an enzyme-activating fragment of human telomerase RNA. RNA (NEW YORK, N.Y.) 2005; 11:394-403. [PMID: 15703438 PMCID: PMC1370729 DOI: 10.1261/rna.7222505] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2004] [Accepted: 12/21/2004] [Indexed: 05/21/2023]
Abstract
The ribonucleoprotein enzyme telomerase ensures the stability and fidelity of linear chromosome ends by elongating the telomeric DNA that is lost during each round of DNA replication. All telomerases contain a catalytic protein component homologous to viral reverse transcriptases (TERT) and an RNA (TR) that provides the template sequence, acts as the scaffold for ribonucleoprotein assembly, and activates the enzyme for catalysis. Vertebrate telomerase RNAs contain three highly conserved structural and functional domains: the template domain, the "CR4-CR5" or "activation" domain essential for activation of the enzymatic activity, and a 3'-terminal "box H/ACA"-homology domain responsible for ribonucleprotein assembly and maturation. Here we report the NMR structure of a functionally essential RNA structural element derived from the human telomerase RNA CR4-CR5 domain. This RNA, referred to as hTR J6, forms a stable hairpin interrupted by a single nucleotide bulge and an asymmetric internal loop. Previous work on telomerase has shown that deletion of the hTR J6 asymmetric internal loop results in an RNA incapable of binding the enzymatic protein component of the RNP and therefore an inactive RNP without telomerase activity. We demonstrate here that the J6 internal loop introduces a twist in the RNA structure that may position the entire domain into the catalytic site of the enzyme.
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Affiliation(s)
- Thomas C Leeper
- Department of Biochemistry and Department of Chemistry, University of Washington, Seattle, WA 98195-1700, USA
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