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Deb S, Berei J, Miliavski E, Khan MJ, Broder TJ, Akurugo TA, Lund C, Fleming SE, Hillwig R, Ross J, Puri N. The Effects of Smoking on Telomere Length, Induction of Oncogenic Stress, and Chronic Inflammatory Responses Leading to Aging. Cells 2024; 13:884. [PMID: 38891017 PMCID: PMC11172003 DOI: 10.3390/cells13110884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Revised: 05/11/2024] [Accepted: 05/18/2024] [Indexed: 06/20/2024] Open
Abstract
Telomeres, potential biomarkers of aging, are known to shorten with continued cigarette smoke exposure. In order to further investigate this process and its impact on cellular stress and inflammation, we used an in vitro model with cigarette smoke extract (CSE) and observed the downregulation of telomere stabilizing TRF2 and POT1 genes after CSE treatment. hTERT is a subunit of telomerase and a well-known oncogenic marker, which is overexpressed in over 85% of cancers and may contribute to lung cancer development in smokers. We also observed an increase in hTERT and ISG15 expression levels after CSE treatment, as well as increased protein levels revealed by immunohistochemical staining in smokers' lung tissue samples compared to non-smokers. The effects of ISG15 overexpression were further studied by quantifying IFN-γ, an inflammatory protein induced by ISG15, which showed greater upregulation in smokers compared to non-smokers. Similar changes in gene expression patterns for TRF2, POT1, hTERT, and ISG15 were observed in blood and buccal swab samples from smokers compared to non-smokers. The results from this study provide insight into the mechanisms behind smoking causing telomere shortening and how this may contribute to the induction of inflammation and/or tumorigenesis, which may lead to comorbidities in smokers.
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Affiliation(s)
- Shreya Deb
- Department of Biomedical Sciences, University of Illinois College of Medicine at Rockford, Rockford, IL 61107, USA; (S.D.); (J.B.); (E.M.); (M.J.K.); (T.J.B.); (T.A.A.); (C.L.)
| | - Joseph Berei
- Department of Biomedical Sciences, University of Illinois College of Medicine at Rockford, Rockford, IL 61107, USA; (S.D.); (J.B.); (E.M.); (M.J.K.); (T.J.B.); (T.A.A.); (C.L.)
| | - Edward Miliavski
- Department of Biomedical Sciences, University of Illinois College of Medicine at Rockford, Rockford, IL 61107, USA; (S.D.); (J.B.); (E.M.); (M.J.K.); (T.J.B.); (T.A.A.); (C.L.)
| | - Muhammad J. Khan
- Department of Biomedical Sciences, University of Illinois College of Medicine at Rockford, Rockford, IL 61107, USA; (S.D.); (J.B.); (E.M.); (M.J.K.); (T.J.B.); (T.A.A.); (C.L.)
| | - Taylor J. Broder
- Department of Biomedical Sciences, University of Illinois College of Medicine at Rockford, Rockford, IL 61107, USA; (S.D.); (J.B.); (E.M.); (M.J.K.); (T.J.B.); (T.A.A.); (C.L.)
| | - Thomas A. Akurugo
- Department of Biomedical Sciences, University of Illinois College of Medicine at Rockford, Rockford, IL 61107, USA; (S.D.); (J.B.); (E.M.); (M.J.K.); (T.J.B.); (T.A.A.); (C.L.)
| | - Cody Lund
- Department of Biomedical Sciences, University of Illinois College of Medicine at Rockford, Rockford, IL 61107, USA; (S.D.); (J.B.); (E.M.); (M.J.K.); (T.J.B.); (T.A.A.); (C.L.)
| | - Sara E. Fleming
- Department of Pathology, UW Health SwedishAmerican Hospital, Rockford, IL 61107, USA;
| | - Robert Hillwig
- Department of Health Sciences Education, University of Illinois College of Medicine at Rockford, Rockford, IL 61107, USA;
| | - Joseph Ross
- Department of Family and Community Medicine, University of Illinois College of Medicine at Rockford, Rockford, IL 61107, USA;
| | - Neelu Puri
- Department of Biomedical Sciences, University of Illinois College of Medicine at Rockford, Rockford, IL 61107, USA; (S.D.); (J.B.); (E.M.); (M.J.K.); (T.J.B.); (T.A.A.); (C.L.)
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2
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Xie JQ, Zhou X, Jia ZC, Su CF, Zhang Y, Fernie AR, Zhang J, Du ZY, Chen MX. Alternative Splicing, An Overlooked Defense Frontier of Plants with Respect to Bacterial Infection. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2023. [PMID: 37916838 DOI: 10.1021/acs.jafc.3c04163] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2023]
Abstract
Disease represents a major problem in sustainable agricultural development. Plants interact closely with various microorganisms during their development and in response to the prevailing environment. In particular, pathogenic microorganisms can cause plant diseases, affecting the fertility, yield, and longevity of plants. During the long coevolution of plants and their pathogens, plants have evolved both molecular pattern-triggered immunity (PTI) and effector-triggered immunity (ETI) signaling networks in order to regulate host cells in response to pathogen infestation. Additionally, in the postgenomic era, alternative splicing (AS) has become uncovered as one of the major drivers of proteome diversity, and abnormal RNA splicing is closely associated with bacterial infections. Currently, the complexity of host-bacteria interactions is a much studied area of research that has shown steady progress over the past decade. Although the development of high-throughput sequencing technologies and their application in transcriptomes have revolutionized our understanding of AS, many mechanisms related to host-bacteria interactions remain still unclear. To this end, this review summarizes the changes observed in AS during host-bacteria interactions and outlines potential therapeutics for bacterial diseases based on existing studies. In doing so, we hope to provide guidelines for plant disease management in agriculture.
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Affiliation(s)
- Ji-Qin Xie
- Key Laboratory of Plant Resource Conservation and Germplasm Innovation in Mountainous Region (Ministry of Education), College of Life Sciences/Institute of Agro-bioengineering, Guizhou University, Guiyang, Guizhou 550025, China
| | - Xiang Zhou
- National Key Laboratory of Green Pesticide, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for R&D of Fine Chemicals of Guizhou University, Guiyang 550025, China
| | - Zi-Chang Jia
- National Key Laboratory of Green Pesticide, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for R&D of Fine Chemicals of Guizhou University, Guiyang 550025, China
| | - Chang-Feng Su
- Key Laboratory of Plant Resource Conservation and Germplasm Innovation in Mountainous Region (Ministry of Education), College of Life Sciences/Institute of Agro-bioengineering, Guizhou University, Guiyang, Guizhou 550025, China
| | - Youjun Zhang
- Center of Plant System Biology and Biotechnology, 4000 Plovdiv, Bulgaria
- Max-Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476 Potsdam, Golm, Germany
| | - Alisdair R Fernie
- Center of Plant System Biology and Biotechnology, 4000 Plovdiv, Bulgaria
- Max-Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476 Potsdam, Golm, Germany
| | - Jianhua Zhang
- Department of Biology, Hong Kong Baptist University, and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Zhi-Yan Du
- Department of Molecular Biosciences & Bioengineering, University of Hawaii at Manoa, Honolulu, Hawaii 96822, United States
| | - Mo-Xian Chen
- National Key Laboratory of Green Pesticide, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for R&D of Fine Chemicals of Guizhou University, Guiyang 550025, China
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3
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Yegorov YE. Olovnikov, Telomeres, and Telomerase. Is It Possible to Prolong a Healthy Life? BIOCHEMISTRY. BIOKHIMIIA 2023; 88:1704-1718. [PMID: 38105192 DOI: 10.1134/s0006297923110032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 08/29/2023] [Accepted: 08/31/2023] [Indexed: 12/19/2023]
Abstract
The science of telomeres and telomerase has made tremendous progress in recent decades. In this review, we consider it first in a historical context (the Carrel-Hayflick-Olovnikov-Blackburn chain of discoveries) and then review current knowledge on the telomere structure and dynamics in norm and pathology. Central to the review are consequences of the telomere shortening, including telomere position effects, DNA damage signaling, and increased genetic instability. Cell senescence and role of telomere length in its development are discussed separately. Therapeutic aspects and risks of telomere lengthening methods including use of telomerase and other approaches are also discussed.
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Affiliation(s)
- Yegor E Yegorov
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, 119991, Russia.
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4
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Kim JJ, Ahn A, Ying J, Hickman E, Ludlow AT. Exercise as a Therapy to Maintain Telomere Function and Prevent Cellular Senescence. Exerc Sport Sci Rev 2023; 51:150-160. [PMID: 37288975 PMCID: PMC10526708 DOI: 10.1249/jes.0000000000000324] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Exercise transiently impacts the expression, regulation, and activity of TERT/telomerase to maintain telomeres and protect the genome from insults. By protecting the telomeres (chromosome ends) and the genome, telomerase promotes cellular survival and prevents cellular senescence. By increasing cellular resiliency, via the actions of telomerase and TERT, exercise promotes healthy aging.
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Affiliation(s)
- Jeongjin J Kim
- School of Kinesiology, University of Michigan, Ann Arbor, MI
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5
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Ali JH, Walter M. Combining old and new concepts in targeting telomerase for cancer therapy: transient, immediate, complete and combinatory attack (TICCA). Cancer Cell Int 2023; 23:197. [PMID: 37679807 PMCID: PMC10483736 DOI: 10.1186/s12935-023-03041-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Accepted: 08/25/2023] [Indexed: 09/09/2023] Open
Abstract
Telomerase can overcome replicative senescence by elongation of telomeres but is also a specific element in most cancer cells. It is expressed more vastly than any other tumor marker. Telomerase as a tumor target inducing replicative immortality can be overcome by only one other mechanism: alternative lengthening of telomeres (ALT). This limits the probability to develop resistance to treatments. Moreover, telomerase inhibition offers some degree of specificity with a low risk of toxicity in normal cells. Nevertheless, only one telomerase antagonist reached late preclinical studies. The underlying causes, the pitfalls of telomerase-based therapies, and future chances based on recent technical advancements are summarized in this review. Based on new findings and approaches, we propose a concept how long-term survival in telomerase-based cancer therapies can be significantly improved: the TICCA (Transient Immediate Complete and Combinatory Attack) strategy.
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Affiliation(s)
- Jaber Haj Ali
- Institute of Laboratory Medicine, Clinical Chemistry and Pathobiochemistry, Charité Universitätsmedizin Berlin, Augustenburger Platz 1, 13353, Berlin, Germany
- Institute of Clinical Chemistry and Laboratory Medicine, Universitätsmedizin Rostock, Ernst-Heydemann-Straße 6, 18057, Rostock, Germany
| | - Michael Walter
- Institute of Clinical Chemistry and Laboratory Medicine, Universitätsmedizin Rostock, Ernst-Heydemann-Straße 6, 18057, Rostock, Germany.
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6
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Karami Fath M, Azargoonjahromi A, Kiani A, Jalalifar F, Osati P, Akbari Oryani M, Shakeri F, Nasirzadeh F, Khalesi B, Nabi-Afjadi M, Zalpoor H, Mard-Soltani M, Payandeh Z. The role of epigenetic modifications in drug resistance and treatment of breast cancer. Cell Mol Biol Lett 2022; 27:52. [PMID: 35764927 PMCID: PMC9238060 DOI: 10.1186/s11658-022-00344-6] [Citation(s) in RCA: 40] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Accepted: 05/24/2022] [Indexed: 02/08/2023] Open
Abstract
Background Breast cancer is defined as a biological and molecular heterogeneous disorder that originates from breast cells. Genetic predisposition is the most important factor giving rise to this malignancy. The most notable mutations in breast cancer occur in the BRCA1 and BRCA2 genes. Owing to disease heterogeneity, lack of therapeutic target, anti-cancer drug resistance, residual disease, and recurrence, researchers are faced with challenges in developing strategies to treat patients with breast cancer. Results It has recently been reported that epigenetic processes such as DNA methylation and histone modification, as well as microRNAs (miRNAs), have potently contributed to the pathophysiology, diagnosis, and treatment of breast cancer. These observations have persuaded researchers to move their therapeutic approaches beyond the genetic framework toward the epigenetic concept. Conclusion Herein we discuss the molecular and epigenetic mechanisms underlying breast cancer progression and resistance as well as various aspects of epigenetic-based therapies as monotherapy and combined with immunotherapy.
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Affiliation(s)
- Mohsen Karami Fath
- Department of Cellular and Molecular Biology, Faculty of Biological Sciences, Kharazmi University, Tehran, Iran
| | | | - Arash Kiani
- Student Research Committee, Yasuj University of Medical Sciences, Yasuj, Iran
| | - Fateme Jalalifar
- School of Medicine, Jiroft University of Medical Sciences, Jiroft, Iran
| | - Parisa Osati
- Chemical Engineering Department, Fouman Faculty of Engineering, College of Engineering, University of Tehran, Fouman, Iran
| | - Mahsa Akbari Oryani
- Department of Pathology, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Fateh Shakeri
- Department of Cellular and Molecular Biology, Faculty of Biological Sciences, Kharazmi University, Tehran, Iran
| | - Farhad Nasirzadeh
- Department of Cellular and Molecular Biology, Faculty of Biological Sciences, Kharazmi University, Tehran, Iran
| | - Behman Khalesi
- Department of Research and Production of Poultry Viral Vaccine, Razi Vaccine and Serum Research Institute, Agricultural Research Education and Extension Organization, Karaj, Iran
| | - Mohsen Nabi-Afjadi
- Department of Biochemistry, Faculty of Biological Science, Tarbiat Modares University, Tehran, Iran
| | - Hamidreza Zalpoor
- Shiraz Neuroscience Research Center, Shiraz University of Medical Sciences, Shiraz, Iran.,Network of Immunity in Infection, Malignancy and Autoimmunity (NIIMA), Universal Scientific Education and Research Network (USERN), Tehran, Iran
| | - Maysam Mard-Soltani
- Department of Clinical Biochemistry, Faculty of Medical Sciences, Dezful University of Medical Sciences, Dezful, Iran.
| | - Zahra Payandeh
- Department Medical Biochemistry and Biophysics, Division Medical Inflammation Research, Karolinska Institute, Stockholm, Sweden.
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7
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MAPK/ERK-CBP-RFPL-3 Mediates Adipose-Derived Stem Cell-Induced Tumor Growth in Breast Cancer Cells by Activating Telomerase Reverse Transcriptase Expression. Stem Cells Int 2022; 2022:8540535. [PMID: 35711680 PMCID: PMC9197637 DOI: 10.1155/2022/8540535] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 04/16/2022] [Accepted: 04/29/2022] [Indexed: 11/26/2022] Open
Abstract
Adipose-derived stem cells (ASCs) improve the self-renewal and survival of fat grafts in breast reconstruction after oncology surgery. However, ASCs have also been found to enhance breast cancer growth, and its role in tumor proliferation remains largely elusive. Here, we explored a novel mechanism that mediates hTERT reactivation during ASC-induced tumor growth in breast cancer cells. In this study, we found the proliferative ability of breast cancer cells markedly increased with ASC coculture. To explore the molecular mechanism, we treated cells with anibody/inhibitor and found that the activation of MEK-ERK pathway was triggered in breast cancer cells by SCF secreted from ASCs, leading to the nuclear recruitment of CBP. As a coactivator of hTERT, CBP subsequently coordinated with RFPL-3 upregulated hTERT transcription and telomerase activity. The inhibition of CBP and RFPL-3 abrogated the activation of hTERT transcription and the promotion of proliferation in breast cancer cells with cocultured ASCs in vitro and in vivo. Collectively, our study findings indicated that CBP coordination with RFPL-3 promotes ASC-induced breast cancer cell proliferation by anchoring to the hTERT promoter and upregulating telomerase activity, which is activated by the MAPK/ERK pathway.
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8
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LPCAT1-TERT fusions are uniquely recurrent in epithelioid trophoblastic tumors and positively regulate cell growth. PLoS One 2021; 16:e0250518. [PMID: 34033669 PMCID: PMC8148365 DOI: 10.1371/journal.pone.0250518] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Accepted: 04/07/2021] [Indexed: 12/03/2022] Open
Abstract
Gestational trophoblastic disease (GTD) is a heterogeneous group of lesions arising from placental tissue. Epithelioid trophoblastic tumor (ETT), derived from chorionic-type trophoblast, is the rarest form of GTD with only approximately 130 cases described in the literature. Due to its morphologic mimicry of epithelioid smooth muscle tumors and carcinoma, ETT can be misdiagnosed. To date, molecular characterization of ETTs is lacking. Furthermore, ETT is difficult to treat when disease spreads beyond the uterus. Here using RNA-Seq analysis in a cohort of ETTs and other gestational trophoblastic lesions we describe the discovery of LPCAT1-TERT fusion transcripts that occur in ETTs and coincide with underlying genomic deletions. Through cell-growth assays we demonstrate that LPCAT1-TERT fusion proteins can positively modulate cell proliferation and therefore may represent future treatment targets. Furthermore, we demonstrate that TERT upregulation appears to be a characteristic of ETTs, even in the absence of LPCAT1-TERT fusions, and that it appears linked to copy number gains of chromosome 5. No evidence of TERT upregulation was identified in other trophoblastic lesions tested, including placental site trophoblastic tumors and placental site nodules, which are thought to be the benign chorionic-type trophoblast counterpart to ETT. These findings indicate that LPCAT1-TERT fusions and copy-number driven TERT activation may represent novel markers for ETT, with the potential to improve the diagnosis, treatment, and outcome for women with this rare form of GTD.
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9
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Plyasova AA, Zhdanov DD. Alternative Splicing of Human Telomerase Reverse Transcriptase (hTERT) and Its Implications in Physiological and Pathological Processes. Biomedicines 2021; 9:526. [PMID: 34065134 PMCID: PMC8150890 DOI: 10.3390/biomedicines9050526] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 05/03/2021] [Accepted: 05/05/2021] [Indexed: 12/24/2022] Open
Abstract
Alternative splicing (AS) of human telomerase catalytic subunit (hTERT, human telomerase reverse transcriptase) pre-mRNA strongly regulates telomerase activity. Several proteins can regulate AS in a cell type-specific manner and determine the functions of cells. In addition to being involved in telomerase activity regulation, AS provides cells with different splice variants that may have alternative biological activities. The modulation of telomerase activity through the induction of hTERT AS is involved in the development of different cancer types and embryos, and the differentiation of stem cells. Regulatory T cells may suppress the proliferation of target human and murine T and B lymphocytes and NK cells in a contact-independent manner involving activation of TERT AS. This review focuses on the mechanism of regulation of hTERT pre-mRNA AS and the involvement of splice variants in physiological and pathological processes.
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Affiliation(s)
| | - Dmitry D. Zhdanov
- Institute of Biomedical Chemistry, Pogodinskaya st 10/8, 119121 Moscow, Russia;
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10
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Dey DK, Kang SC. CopA3 peptide induces permanent cell-cycle arrest in colorectal cancer cells. Mech Ageing Dev 2021; 196:111497. [PMID: 33957217 DOI: 10.1016/j.mad.2021.111497] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 04/27/2021] [Accepted: 04/29/2021] [Indexed: 12/23/2022]
Abstract
Cell-cycle arrest reflects an accumulation of responses to DNA damage that sequentially affects cell growth and division. Herein, we analyzed the effect of the 9-mer dimer defensin-like peptide, CopA3, against colorectal cancer cell growth and proliferation in a dose-dependent manner upon 96 h of treatment. As observed, CopA3 treatment significantly affected cancer cell growth, reduced colony formation ability, increased the number of SA-β-Gal positive cells, and remarkably reduced Ki67 protein expression. Notably, in HCT-116 cells, CopA3 (5 μM) treatment effectively increased oxidative stress and, as a result, amplified the endogenous ROS, mitochondrial ROS, and NO content in the cells, which further activated the DNA damage response and caused cell-cycle arrest at the G1 phase. The prolonged cell-cycle arrest elevated the release of inflammatory cytokines in the cell supernatant. Nevertheless, mechanistically, NAC treatment effectively reversed the CopA3 effect and significantly reduced the oxidative stress; subsequently rescuing the cells from G1 phase arrest. Overall, CopA3 treatment can inhibit the growth and proliferation of colorectal cancer cells by inducing cell-cycle arrest through the ROS-mediated pathway.
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Affiliation(s)
- Debasish Kumar Dey
- Department of Biotechnology, Daegu University, Gyeongsan, Gyeongbuk, 38453, Republic of Korea.
| | - Sun Chul Kang
- Department of Biotechnology, Daegu University, Gyeongsan, Gyeongbuk, 38453, Republic of Korea.
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11
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Nersisyan L, Simonyan A, Binder H, Arakelyan A. Telomere Maintenance Pathway Activity Analysis Enables Tissue- and Gene-Level Inferences. Front Genet 2021; 12:662464. [PMID: 33897770 PMCID: PMC8058386 DOI: 10.3389/fgene.2021.662464] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 03/16/2021] [Indexed: 12/31/2022] Open
Abstract
Telomere maintenance is one of the mechanisms ensuring indefinite divisions of cancer and stem cells. Good understanding of telomere maintenance mechanisms (TMM) is important for studying cancers and designing therapies. However, molecular factors triggering selective activation of either the telomerase dependent (TEL) or the alternative lengthening of telomeres (ALT) pathway are poorly understood. In addition, more accurate and easy-to-use methodologies are required for TMM phenotyping. In this study, we have performed literature based reconstruction of signaling pathways for the ALT and TEL TMMs. Gene expression data were used for computational assessment of TMM pathway activities and compared with experimental assays for TEL and ALT. Explicit consideration of pathway topology makes bioinformatics analysis more informative compared to computational methods based on simple summary measures of gene expression. Application to healthy human tissues showed high ALT and TEL pathway activities in testis, and identified genes and pathways that may trigger TMM activation. Our approach offers a novel option for systematic investigation of TMM activation patterns across cancers and healthy tissues for dissecting pathway-based molecular markers with diagnostic impact.
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Affiliation(s)
- Lilit Nersisyan
- Bioinformatics Group, Institute of Molecular Biology, National Academy of Sciences, Yerevan, Armenia.,Pathverse, Yerevan, Armenia
| | - Arman Simonyan
- Bioinformatics Group, Institute of Molecular Biology, National Academy of Sciences, Yerevan, Armenia
| | - Hans Binder
- Interdisciplinary Center for Bioinformatics, University of Leipzig, Leipzig, Germany
| | - Arsen Arakelyan
- Bioinformatics Group, Institute of Molecular Biology, National Academy of Sciences, Yerevan, Armenia.,Pathverse, Yerevan, Armenia
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12
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Yegorov YE, Poznyak AV, Nikiforov NG, Starodubova AV, Orekhov AN. Role of Telomeres Shortening in Atherogenesis: An Overview. Cells 2021; 10:395. [PMID: 33671887 PMCID: PMC7918954 DOI: 10.3390/cells10020395] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Revised: 02/07/2021] [Accepted: 02/13/2021] [Indexed: 02/07/2023] Open
Abstract
It is known that the shortening of the telomeres leads to cell senescence, accompanied by acquiring of pro-inflammatory phenotype. The expression of telomerase can elongate telomeres and resist the onset of senescence. The initiation of atherosclerosis is believed to be associated with local senescence of the endothelial cells of the arteries in places with either low or multidirectional oscillatory wall shear stress. The process of regeneration of the artery surface that has begun does not lead to success for several reasons. Atherosclerotic plaques are formed, which, when developed, lead to fatal consequences, which are the leading causes of death in the modern world. The pronounced age dependence of the manifestations of atherosclerosis pushes scientists to try to link the development of atherosclerosis with telomere length. The study of the role of telomere shortening in atherosclerosis is mainly limited to measuring the telomeres of blood cells, and only in rare cases (surgery or post-mortem examination) are the telomeres of local cells available for measurement. The review discusses the basic issues of cellular aging and the interpretation of telomere measurement data in atherosclerosis, as well as the prospects for the prevention and possible treatment of atherosclerosis.
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Affiliation(s)
- Yegor E. Yegorov
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow 119991, Russia;
| | - Anastasia V. Poznyak
- Institute for Atherosclerosis Research, Skolkovo Innovative Center, Moscow 121609, Russia
| | - Nikita G. Nikiforov
- Laboratory of Angiopathology, Institute of General Pathology and Pathophysiology, Moscow 125315, Russia;
- National Medical Research Center of Cardiology, Institute of Experimental Cardiology, Moscow 121552, Russia
- Institute of Gene Biology, Center of Collective Usage, Moscow 119334, Russia
| | - Antonina V. Starodubova
- Federal Research Centre for Nutrition, Biotechnology and Food Safety, Moscow 109240, Russia;
- Pirogov Russian National Research Medical University, Moscow 117997, Russia
| | - Alexander N. Orekhov
- Institute for Atherosclerosis Research, Skolkovo Innovative Center, Moscow 121609, Russia
- Laboratory of Angiopathology, Institute of General Pathology and Pathophysiology, Moscow 125315, Russia;
- Institute of Human Morphology, Moscow 117418, Russia
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13
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Noureen N, Wu S, Lv Y, Yang J, Alfred Yung WK, Gelfond J, Wang X, Koul D, Ludlow A, Zheng S. Integrated analysis of telomerase enzymatic activity unravels an association with cancer stemness and proliferation. Nat Commun 2021; 12:139. [PMID: 33420056 PMCID: PMC7794223 DOI: 10.1038/s41467-020-20474-9] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 12/03/2020] [Indexed: 12/11/2022] Open
Abstract
Active telomerase is essential for stem cells and most cancers to maintain telomeres. The enzymatic activity of telomerase is related but not equivalent to the expression of TERT, the catalytic subunit of the complex. Here we show that telomerase enzymatic activity can be robustly estimated from the expression of a 13-gene signature. We demonstrate the validity of the expression-based approach, named EXTEND, using cell lines, cancer samples, and non-neoplastic samples. When applied to over 9,000 tumors and single cells, we find a strong correlation between telomerase activity and cancer stemness. This correlation is largely driven by a small population of proliferating cancer cells that exhibits both high telomerase activity and cancer stemness. This study establishes a computational framework for quantifying telomerase enzymatic activity and provides new insights into the relationships among telomerase, cancer proliferation, and stemness.
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Affiliation(s)
- Nighat Noureen
- Greehey Children's Cancer Research Institute, UT Health San Antonio, San Antonio, TX, USA
- Department of Population Health Sciences, UT Health San Antonio, San Antonio, TX, USA
| | - Shaofang Wu
- Department of Neuro-Oncology, MD Anderson Cancer Center, Houston, TX, USA
| | - Yingli Lv
- Greehey Children's Cancer Research Institute, UT Health San Antonio, San Antonio, TX, USA
| | - Juechen Yang
- Greehey Children's Cancer Research Institute, UT Health San Antonio, San Antonio, TX, USA
| | - W K Alfred Yung
- Department of Neuro-Oncology, MD Anderson Cancer Center, Houston, TX, USA
| | - Jonathan Gelfond
- Department of Population Health Sciences, UT Health San Antonio, San Antonio, TX, USA
| | - Xiaojing Wang
- Greehey Children's Cancer Research Institute, UT Health San Antonio, San Antonio, TX, USA
- Department of Population Health Sciences, UT Health San Antonio, San Antonio, TX, USA
| | - Dimpy Koul
- Department of Neuro-Oncology, MD Anderson Cancer Center, Houston, TX, USA
| | - Andrew Ludlow
- Department of Movement Science, University of Michigan, Ann Arbor, MI, USA
| | - Siyuan Zheng
- Greehey Children's Cancer Research Institute, UT Health San Antonio, San Antonio, TX, USA.
- Department of Population Health Sciences, UT Health San Antonio, San Antonio, TX, USA.
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14
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Endometriosis Is Associated with a Significant Increase in hTERC and Altered Telomere/Telomerase Associated Genes in the Eutopic Endometrium, an Ex-Vivo and In Silico Study. Biomedicines 2020; 8:biomedicines8120588. [PMID: 33317189 PMCID: PMC7764055 DOI: 10.3390/biomedicines8120588] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 12/02/2020] [Accepted: 12/03/2020] [Indexed: 12/13/2022] Open
Abstract
Telomeres protect chromosomal ends and they are maintained by the specialised enzyme, telomerase. Endometriosis is a common gynaecological disease and high telomerase activity and higher hTERT levels associated with longer endometrial telomere lengths are characteristics of eutopic secretory endometrial aberrations of women with endometriosis. Our ex-vivo study examined the levels of hTERC and DKC1 RNA and dyskerin protein levels in the endometrium from healthy women and those with endometriosis (n = 117). The in silico study examined endometriosis-specific telomere- and telomerase-associated gene (TTAG) transcriptional aberrations of secretory phase eutopic endometrium utilising publicly available microarray datasets. Eutopic secretory endometrial hTERC levels were significantly increased in women with endometriosis compared to healthy endometrium, yet dyskerin mRNA and protein levels were unperturbed. Our in silico study identified 10 TTAGs (CDKN2A, PML, ZNHIT2, UBE3A, MCCC2, HSPC159, FGFR2, PIK3C2A, RALGAPA1, and HNRNPA2B1) to be altered in mid-secretory endometrium of women with endometriosis. High levels of hTERC and the identified other TTAGs might be part of the established alteration in the eutopic endometrial telomerase biology in women with endometriosis in the secretory phase of the endometrium and our data informs future research to unravel the fundamental involvement of telomerase in the pathogenesis of endometriosis.
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15
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Vedelek B, Maddali AK, Davenova N, Vedelek V, Boros IM. TERT promoter alterations could provide a solution for Peto's paradox in rodents. Sci Rep 2020; 10:20815. [PMID: 33257697 PMCID: PMC7704627 DOI: 10.1038/s41598-020-77648-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Accepted: 11/13/2020] [Indexed: 12/19/2022] Open
Abstract
Cancer is a genetic disease caused by changes in gene expression resulting from somatic mutations and epigenetic changes. Although the probability of mutations is proportional with cell number and replication cycles, large bodied species do not develop cancer more frequently than smaller ones. This notion is known as Peto's paradox, and assumes stronger tumor suppression in larger animals. One of the possible tumor suppressor mechanisms involved could be replicative senescence caused by telomere shortening in the absence of telomerase activity. We analysed telomerase promoter activity and transcription factor binding in mammals to identify the key element of telomerase gene inactivation. We found that the GABPA transcription factor plays a key role in TERT regulation in somatic cells of small rodents, but its binding site is absent in larger beavers. Protein binding and reporter gene assays verify different use of this site in different species. The presence or absence of the GABPA TF site in TERT promoters of rodents correlates with TERT promoter activity; thus it could determine whether replicative senescence plays a tumor suppressor role in these species, which could be in direct relation with body mass. The GABPA TF binding sites that contribute to TERT activity in somatic cells of rodents are analogous to those mutated in human tumors, which activate telomerase by a non-ALT mechanism.
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Affiliation(s)
- Balázs Vedelek
- Department of Biochemistry and Molecular Biology, University of Szeged, Szeged, Hungary
- Institute of Biochemistry, Biological Research Centre, Szeged, Hungary
| | - Asha Kiran Maddali
- Department of Biochemistry and Molecular Biology, University of Szeged, Szeged, Hungary
- Institute of Genetics, Biological Research Centre, Szeged, Hungary
| | - Nurgul Davenova
- Department of Biochemistry and Molecular Biology, University of Szeged, Szeged, Hungary
| | - Viktor Vedelek
- Department of Genetics, University of Szeged, Szeged, Hungary
| | - Imre M Boros
- Department of Biochemistry and Molecular Biology, University of Szeged, Szeged, Hungary.
- Institute of Biochemistry, Biological Research Centre, Szeged, Hungary.
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16
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Schrumpfová PP, Fajkus J. Composition and Function of Telomerase-A Polymerase Associated with the Origin of Eukaryotes. Biomolecules 2020; 10:biom10101425. [PMID: 33050064 PMCID: PMC7658794 DOI: 10.3390/biom10101425] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 09/29/2020] [Accepted: 10/01/2020] [Indexed: 12/19/2022] Open
Abstract
The canonical DNA polymerases involved in the replication of the genome are unable to fully replicate the physical ends of linear chromosomes, called telomeres. Chromosomal termini thus become shortened in each cell cycle. The maintenance of telomeres requires telomerase—a specific RNA-dependent DNA polymerase enzyme complex that carries its own RNA template and adds telomeric repeats to the ends of chromosomes using a reverse transcription mechanism. Both core subunits of telomerase—its catalytic telomerase reverse transcriptase (TERT) subunit and telomerase RNA (TR) component—were identified in quick succession in Tetrahymena more than 30 years ago. Since then, both telomerase subunits have been described in various organisms including yeasts, mammals, birds, reptiles and fish. Despite the fact that telomerase activity in plants was described 25 years ago and the TERT subunit four years later, a genuine plant TR has only recently been identified by our group. In this review, we focus on the structure, composition and function of telomerases. In addition, we discuss the origin and phylogenetic divergence of this unique RNA-dependent DNA polymerase as a witness of early eukaryotic evolution. Specifically, we discuss the latest information regarding the recently discovered TR component in plants, its conservation and its structural features.
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Affiliation(s)
- Petra Procházková Schrumpfová
- Laboratory of Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kotlářská 2, CZ-61137 Brno, Czech Republic;
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk University, Kamenice 5, CZ-62500 Brno, Czech Republic
- Correspondence:
| | - Jiří Fajkus
- Laboratory of Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kotlářská 2, CZ-61137 Brno, Czech Republic;
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk University, Kamenice 5, CZ-62500 Brno, Czech Republic
- The Czech Academy of Sciences, Institute of Biophysics, Královopolská 135, 612 65 Brno, Czech Republic
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17
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Luo C, Zhu X, Luo Q, Bu F, Huang C, Zhu J, Zhao J, Zhang W, Lin K, Hu C, Zong Z, Luo H, Huang J, Zhu Z. RBFOX3 Promotes Gastric Cancer Growth and Progression by Activating HTERT Signaling. Front Oncol 2020; 10:1044. [PMID: 32903312 PMCID: PMC7396657 DOI: 10.3389/fonc.2020.01044] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Accepted: 05/26/2020] [Indexed: 12/30/2022] Open
Abstract
Tumor invasion, metastasis, and recrudescence remain a considerable challenge in the treatment of gastric cancer (GC). Herein we first identified that RNA binding protein fox-1 homolog 3 (RBFOX3) was markedly overexpressed in GC tissues and negatively linked to the survival rate of GC patients. RBFOX3 promoted cell division and cell cycle progression in vitro and in vivo. Furthermore, RBFOX3 increased the cell invasion and migration ability. The suppression of GC cell multiplication and invasion, caused by silencing of RBFOX3, was rescued by HTERT overexpression. Additionally, RBFOX3 augmented the resistance of GC cells to 5-fluorouracil by repressing RBFOX3. Mechanistically, the exogenous up-regulation of RBFOX3 triggered promoter activity and HTERT expression, thereby enhancing the division and the development of GC cells. Further co-immunoprecipitation tests revealed that RBFOX3 bound to AP-2β to modulate HTERT expression. In conclusion, our study indicates that a high expression of RBFOX3 promotes GC progression and development and predicts worse prognosis. Collectively, these results indicate that the RBFOX3/AP-2β/HTERT signaling pathway can be therapeutically targeted to prevent and treat GC recurrence and metastasis.
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Affiliation(s)
- Chen Luo
- Department of General Surgery, The Second Affiliated Hospital of Nanchang University, Nanchang, China.,Department of Clinical Medical, Jiangxi Medical College of Nanchang University, Nanchang, China.,Jiangxi Province Key Laboratory of Molecular Medicine, Nanchang, China
| | - Xiaojian Zhu
- Department of General Surgery, The Second Affiliated Hospital of Nanchang University, Nanchang, China.,Department of Clinical Medical, Jiangxi Medical College of Nanchang University, Nanchang, China.,Jiangxi Province Key Laboratory of Molecular Medicine, Nanchang, China
| | - Qilin Luo
- Department of General Surgery, The Second Affiliated Hospital of Nanchang University, Nanchang, China
| | - Fanqin Bu
- Department of General Surgery, The Second Affiliated Hospital of Nanchang University, Nanchang, China.,Department of Clinical Medical, Jiangxi Medical College of Nanchang University, Nanchang, China.,Jiangxi Province Key Laboratory of Molecular Medicine, Nanchang, China
| | - Chao Huang
- Department of General Surgery, The Second Affiliated Hospital of Nanchang University, Nanchang, China.,Department of Clinical Medical, Jiangxi Medical College of Nanchang University, Nanchang, China.,Jiangxi Province Key Laboratory of Molecular Medicine, Nanchang, China
| | - Jingfeng Zhu
- Department of General Surgery, The Second Affiliated Hospital of Nanchang University, Nanchang, China.,Department of Clinical Medical, Jiangxi Medical College of Nanchang University, Nanchang, China.,Jiangxi Province Key Laboratory of Molecular Medicine, Nanchang, China
| | - Jiefeng Zhao
- Department of General Surgery, The Second Affiliated Hospital of Nanchang University, Nanchang, China.,Department of Clinical Medical, Jiangxi Medical College of Nanchang University, Nanchang, China.,Jiangxi Province Key Laboratory of Molecular Medicine, Nanchang, China
| | - Wenjun Zhang
- Department of General Surgery, The Second Affiliated Hospital of Nanchang University, Nanchang, China.,Department of Clinical Medical, Jiangxi Medical College of Nanchang University, Nanchang, China.,Jiangxi Province Key Laboratory of Molecular Medicine, Nanchang, China
| | - Kang Lin
- Department of General Surgery, The Second Affiliated Hospital of Nanchang University, Nanchang, China.,Department of Clinical Medical, Jiangxi Medical College of Nanchang University, Nanchang, China.,Jiangxi Province Key Laboratory of Molecular Medicine, Nanchang, China
| | - Cegui Hu
- Department of Clinical Medical, Jiangxi Medical College of Nanchang University, Nanchang, China.,Jiangxi Province Key Laboratory of Molecular Medicine, Nanchang, China
| | - Zeng Zong
- Department of General Surgery, The Second Affiliated Hospital of Nanchang University, Nanchang, China.,Jiangxi Province Key Laboratory of Molecular Medicine, Nanchang, China
| | - Hongliang Luo
- Department of General Surgery, The Second Affiliated Hospital of Nanchang University, Nanchang, China.,Jiangxi Province Key Laboratory of Molecular Medicine, Nanchang, China
| | - Jun Huang
- Department of General Surgery, The Second Affiliated Hospital of Nanchang University, Nanchang, China
| | - Zhengming Zhu
- Department of General Surgery, The Second Affiliated Hospital of Nanchang University, Nanchang, China
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18
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Fernandes SG, Dsouza R, Pandya G, Kirtonia A, Tergaonkar V, Lee SY, Garg M, Khattar E. Role of Telomeres and Telomeric Proteins in Human Malignancies and Their Therapeutic Potential. Cancers (Basel) 2020; 12:E1901. [PMID: 32674474 PMCID: PMC7409176 DOI: 10.3390/cancers12071901] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 07/10/2020] [Accepted: 07/13/2020] [Indexed: 12/19/2022] Open
Abstract
Telomeres are the ends of linear chromosomes comprised of repetitive nucleotide sequences in humans. Telomeres preserve chromosomal stability and genomic integrity. Telomere length shortens with every cell division in somatic cells, eventually resulting in replicative senescence once telomere length becomes critically short. Telomere shortening can be overcome by telomerase enzyme activity that is undetectable in somatic cells, while being active in germline cells, stem cells, and immune cells. Telomeres are bound by a shelterin complex that regulates telomere lengthening as well as protects them from being identified as DNA damage sites. Telomeres are transcribed by RNA polymerase II, and generate a long noncoding RNA called telomeric repeat-containing RNA (TERRA), which plays a key role in regulating subtelomeric gene expression. Replicative immortality and genome instability are hallmarks of cancer and to attain them cancer cells exploit telomere maintenance and telomere protection mechanisms. Thus, understanding the role of telomeres and their associated proteins in cancer initiation, progression and treatment is very important. The present review highlights the critical role of various telomeric components with recently established functions in cancer. Further, current strategies to target various telomeric components including human telomerase reverse transcriptase (hTERT) as a therapeutic approach in human malignancies are discussed.
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Affiliation(s)
- Stina George Fernandes
- Sunandan Divatia School of Science, SVKM’s NMIMS (Deemed to be University), Vile Parle West, Mumbai 400056, India; (S.G.F.); (R.D.)
| | - Rebecca Dsouza
- Sunandan Divatia School of Science, SVKM’s NMIMS (Deemed to be University), Vile Parle West, Mumbai 400056, India; (S.G.F.); (R.D.)
| | - Gouri Pandya
- Amity Institute of Molecular Medicine and Stem Cell Research (AIMMSCR), Amity University Uttar Pradesh, Noida 201313, India; (G.P.); (A.K.)
| | - Anuradha Kirtonia
- Amity Institute of Molecular Medicine and Stem Cell Research (AIMMSCR), Amity University Uttar Pradesh, Noida 201313, India; (G.P.); (A.K.)
| | - Vinay Tergaonkar
- Laboratory of NF-κB Signaling, Institute of Molecular and Cell Biology (IMCB), 61 Biopolis Drive, Proteos, Singapore 138673, Singapore; (V.T.); (S.Y.L.)
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore (NUS), Singapore 117597, Singapore
- Department of Pathology, Yong Loo Lin School of Medicine, National University of Singapore (NUS), Singapore 117597, Singapore
| | - Sook Y. Lee
- Laboratory of NF-κB Signaling, Institute of Molecular and Cell Biology (IMCB), 61 Biopolis Drive, Proteos, Singapore 138673, Singapore; (V.T.); (S.Y.L.)
| | - Manoj Garg
- Amity Institute of Molecular Medicine and Stem Cell Research (AIMMSCR), Amity University Uttar Pradesh, Noida 201313, India; (G.P.); (A.K.)
| | - Ekta Khattar
- Sunandan Divatia School of Science, SVKM’s NMIMS (Deemed to be University), Vile Parle West, Mumbai 400056, India; (S.G.F.); (R.D.)
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19
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Telomerase Biogenesis and Activities from the Perspective of Its Direct Interacting Partners. Cancers (Basel) 2020; 12:cancers12061679. [PMID: 32599885 PMCID: PMC7352425 DOI: 10.3390/cancers12061679] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 06/20/2020] [Accepted: 06/22/2020] [Indexed: 12/15/2022] Open
Abstract
Telomerase reverse transcriptase (TERT)—the catalytic subunit of telomerase—is reactivated in up to 90% of all human cancers. TERT is observed in heterogenous populations of protein complexes, which are dynamically regulated in a cell type- and cell cycle-specific manner. Over the past two decades, in vitro protein–protein interaction detection methods have discovered a number of endogenous TERT binding partners in human cells that are responsible for the biogenesis and functionalization of the telomerase holoenzyme, including the processes of TERT trafficking between subcellular compartments, assembly into telomerase, and catalytic action at telomeres. Additionally, TERT have been found to interact with protein species with no known telomeric functions, suggesting that these complexes may contribute to non-canonical activities of TERT. Here, we survey TERT direct binding partners and discuss their contributions to TERT biogenesis and functions. The goal is to review the comprehensive spectrum of TERT pro-malignant activities, both telomeric and non-telomeric, which may explain the prevalence of its upregulation in cancer.
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20
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Slusher AL, Kim JJJ, Ludlow AT. The Role of Alternative RNA Splicing in the Regulation of hTERT, Telomerase, and Telomeres: Implications for Cancer Therapeutics. Cancers (Basel) 2020; 12:E1514. [PMID: 32531916 PMCID: PMC7352778 DOI: 10.3390/cancers12061514] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 06/01/2020] [Accepted: 06/08/2020] [Indexed: 12/13/2022] Open
Abstract
Alternative RNA splicing impacts the majority (>90%) of eukaryotic multi-exon genes, expanding the coding capacity and regulating the abundance of gene isoforms. Telomerase (hTERT) is a key example of a gene that is alternatively spliced during human fetal development and becomes dysregulated in nearly all cancers. Approximately 90% of human tumors use telomerase to synthesize de novo telomere repeats and obtain telomere-dependent cellular immortality. Paradigm shifting data indicates that hTERT alternative splicing, in addition to transcription, plays an important role in the regulation of active telomerase in cells. Our group and others are pursuing the basic science studies to progress this emerging area of telomerase biology. Recent evidence demonstrates that switching splicing of hTERT from the telomerase activity producing full-length hTERT isoform to alternatively spliced, non-coding isoforms may be a novel telomerase inhibition strategy to prevent cancer growth and survival. Thus, the goals of this review are to detail the general roles of telomerase in cancer development, explore the emerging regulatory mechanisms of alternative RNA splicing of the hTERT gene in various somatic and cancer cell types, define the known and potential roles of hTERT splice isoforms in cancer cell biology, and provide insight into new treatment strategies targeting hTERT in telomerase-positive cancers.
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Affiliation(s)
| | | | - Andrew T. Ludlow
- School of Kinesiology, University of Michigan, Ann Arbor, MI 48109, USA; (A.L.S.); (J.J.K.)
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21
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Applications of Bioinformatics in Cancer. Cancers (Basel) 2019; 11:cancers11111630. [PMID: 31652939 PMCID: PMC6893424 DOI: 10.3390/cancers11111630] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Accepted: 10/23/2019] [Indexed: 01/02/2023] Open
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22
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Loh HY, Norman BP, Lai KS, Rahman NMANA, Alitheen NBM, Osman MA. The Regulatory Role of MicroRNAs in Breast Cancer. Int J Mol Sci 2019; 20:E4940. [PMID: 31590453 PMCID: PMC6801796 DOI: 10.3390/ijms20194940] [Citation(s) in RCA: 187] [Impact Index Per Article: 37.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Revised: 08/21/2019] [Accepted: 08/23/2019] [Indexed: 02/06/2023] Open
Abstract
MicroRNAs (miRNAs) are small non-coding RNA molecules which function as critical post-transcriptional gene regulators of various biological functions. Generally, miRNAs negatively regulate gene expression by binding to their selective messenger RNAs (mRNAs), thereby leading to either mRNA degradation or translational repression, depending on the degree of complementarity with target mRNA sequences. Aberrant expression of these miRNAs has been linked etiologically with various human diseases including breast cancer. Different cellular pathways of breast cancer development such as cell proliferation, apoptotic response, metastasis, cancer recurrence and chemoresistance are regulated by either the oncogenic miRNA (oncomiR) or tumor suppressor miRNA (tsmiR). In this review, we highlight the current state of research into miRNA involved in breast cancer, with particular attention to articles published between the years 2000 to 2019, using detailed searches of the databases PubMed, Google Scholar, and Scopus. The post-transcriptional gene regulatory roles of various dysregulated miRNAs in breast cancer and their potential as therapeutic targets are also discussed.
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Affiliation(s)
- Hui-Yi Loh
- Department of Cell and Molecular Biology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, Serdang, Selangor 43400, Malaysia.
| | - Brendan P Norman
- Department of Musculoskeletal Biology, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool L7 8TX, UK.
| | - Kok-Song Lai
- Health Sciences Division, Abu Dhabi Women's College, Higher Colleges of Technology, Abu Dhabi 41012, UAE.
| | - Nik Mohd Afizan Nik Abd Rahman
- Department of Cell and Molecular Biology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, Serdang, Selangor 43400, Malaysia.
| | - Noorjahan Banu Mohamed Alitheen
- Department of Cell and Molecular Biology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, Serdang, Selangor 43400, Malaysia.
| | - Mohd Azuraidi Osman
- Department of Cell and Molecular Biology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, Serdang, Selangor 43400, Malaysia.
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