1
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Jayaprasad AG, Chandrasekharan A, Arun Jyothi SP, John Sam SM, Santhoshkumar TR, Pillai MR. Telomerase inhibitors induce mitochondrial oxidation and DNA damage-dependent cell death rescued by Bcl-2/Bcl-xL. Int J Biol Macromol 2024; 264:130151. [PMID: 38403227 DOI: 10.1016/j.ijbiomac.2024.130151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Revised: 02/05/2024] [Accepted: 02/11/2024] [Indexed: 02/27/2024]
Abstract
BACKGROUND Reactivation of telomerase is a hallmark of cancer and the majority of cancers over-express telomerase. Telomerase-dependent telomere length maintenance confers immortality to cancer cells. However, telomere length-independent cell survival functions of telomerase also play a critical role in tumorigenesis. Multiple telomerase inhibitors have been developed as therapeutics and include anti-sense oligonucleotides, telomerase RNA component targeting agents, chemical inhibitors of telomerase, small molecule inhibitors of hTERT, and telomerase vaccine. In general, telomerase inhibitors affect cell proliferation and survival of cells depending on the telomere length reduction, culminating in replicative senescence or cell death by crisis. However, most telomerase inhibitors kill cancer cells prior to significant reduction in telomere length, suggesting telomere length independent role of telomerase in early telomere dysfunction-dependent cell death. METHODS In this study, we explored the mechanism of cell death induced by three prominent telomerase inhibitors utilizing a series of genetically encoded sensor cells including redox and DNA damage sensor cells. RESULTS We report that telomerase inhibitors induce early cell cycle inhibition, followed by redox alterations at cytosol and mitochondria. Massive mitochondrial oxidation and DNA damage induce classical cell death involving mitochondrial transmembrane potential loss and mitochondrial permeabilization. Real-time imaging of the progression of mitochondrial oxidation revealed that treated cells undergo a biphasic mitochondrial redox alteration during telomerase inhibition, emphasizing the potential role of telomerase in the redox regulation at mitochondria. Additionally, silencing of hTERT confirmed its predominant role in maintaining mitochondrial redox homeostasis. Interestingly, the study also demonstrated that anti-apoptotic Bcl-2 family proteins still confer protection against cell death induced by telomerase inhibitors. CONCLUSION The study demonstrates that redox alterations and DNA damage contribute to early cell death by telomerase inhibitors and anti-apoptotic Bcl-2 family proteins confer protection from cell death by their ability to safeguard mitochondria from oxidation damage.
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Affiliation(s)
- Aparna Geetha Jayaprasad
- Cancer Research Program, Rajiv Gandhi Centre for Biotechnology, Poojappura, Thycaud, Thiruvananthapuram 695014, Kerala, India; PhD Program, Manipal Academy of Higher Education (MAHE), Madhav Nagar, Manipal, Karnataka 576104, India
| | - Aneesh Chandrasekharan
- Cancer Research Program, Rajiv Gandhi Centre for Biotechnology, Poojappura, Thycaud, Thiruvananthapuram 695014, Kerala, India
| | - S P Arun Jyothi
- Cancer Research Program, Rajiv Gandhi Centre for Biotechnology, Poojappura, Thycaud, Thiruvananthapuram 695014, Kerala, India
| | - S M John Sam
- Cancer Research Program, Rajiv Gandhi Centre for Biotechnology, Poojappura, Thycaud, Thiruvananthapuram 695014, Kerala, India
| | - T R Santhoshkumar
- Cancer Research Program, Rajiv Gandhi Centre for Biotechnology, Poojappura, Thycaud, Thiruvananthapuram 695014, Kerala, India.
| | - M Radhakrishna Pillai
- Cancer Research Program, Rajiv Gandhi Centre for Biotechnology, Poojappura, Thycaud, Thiruvananthapuram 695014, Kerala, India.
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2
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Ait-Aissa K, Norwood-Toro LE, Terwoord J, Young M, Paniagua LA, Hader SN, Hughes WE, Hockenberry JC, Beare JE, Linn J, Kohmoto T, Kim J, Betts DH, LeBlanc AJ, Gutterman DD, Beyer AM. Noncanonical Role of Telomerase in Regulation of Microvascular Redox Environment With Implications for Coronary Artery Disease. FUNCTION (OXFORD, ENGLAND) 2022; 3:zqac043. [PMID: 36168588 PMCID: PMC9508843 DOI: 10.1093/function/zqac043] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Revised: 08/05/2022] [Accepted: 08/11/2022] [Indexed: 01/28/2023]
Abstract
Telomerase reverse transcriptase (TERT) (catalytic subunit of telomerase) is linked to the development of coronary artery disease (CAD); however, whether the role of nuclear vs. mitchondrial actions of TERT is involved is not determined. Dominant-negative TERT splice variants contribute to decreased mitochondrial integrity and promote elevated reactive oxygen species production. We hypothesize that a decrease in mitochondrial TERT would increase mtDNA damage, promoting a pro-oxidative redox environment. The goal of this study is to define whether mitochondrial TERT is sufficient to maintain nitric oxide as the underlying mechanism of flow-mediated dilation by preserving mtDNA integrity.Immunoblots and quantitative polymerase chain reaction were used to show elevated levels of splice variants α- and β-deletion TERT tissue from subjects with and without CAD. Genetic, pharmacological, and molecular tools were used to manipulate TERT localization. Isolated vessel preparations and fluorescence-based quantification of mtH2O2 and NO showed that reduction of TERT in the nucleus increased flow induced NO and decreased mtH2O2 levels, while prevention of mitochondrial import of TERT augmented pathological effects. Further elevated mtDNA damage was observed in tissue from subjects with CAD and initiation of mtDNA repair mechanisms was sufficient to restore NO-mediated dilation in vessels from patients with CAD. The work presented is the first evidence that catalytically active mitochondrial TERT, independent of its nuclear functions, plays a critical physiological role in preserving NO-mediated vasodilation and the balance of mitochondrial to nuclear TERT is fundamentally altered in states of human disease that are driven by increased expression of dominant negative splice variants.
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Affiliation(s)
- K Ait-Aissa
- Department of Internal Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - L E Norwood-Toro
- Department of Medicine, Medical College of Wisconsin, Milwaukee, WI 53226, USA,Cardiovascular Center, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - J Terwoord
- Department of Medicine, Medical College of Wisconsin, Milwaukee, WI 53226, USA,Cardiovascular Center, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - M Young
- Department of Medicine, Medical College of Wisconsin, Milwaukee, WI 53226, USA,Cardiovascular Center, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - L A Paniagua
- Department of Medicine, Medical College of Wisconsin, Milwaukee, WI 53226, USA,Cardiovascular Innovation Institute, University of Louisville, Louisville, KY 40292, USA
| | - S N Hader
- Department of Medicine, Medical College of Wisconsin, Milwaukee, WI 53226, USA,Cardiovascular Center, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - W E Hughes
- Department of Internal Medicine, University of Iowa, Iowa City, IA 52242, USA,Cardiovascular Center, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - J C Hockenberry
- Department of Medicine, Medical College of Wisconsin, Milwaukee, WI 53226, USA,Cardiovascular Center, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - J E Beare
- Cardiovascular Innovation Institute, University of Louisville, Louisville, KY 40292, USA,Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, KY 40292, USA
| | - J Linn
- Department of Medicine, Medical College of Wisconsin, Milwaukee, WI 53226, USA,Cardiovascular Center, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - T Kohmoto
- Department of Surgery, Division of Cardiothoracic Surgery, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - J Kim
- Department of Physiology and Pharmacology, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, ON N6A 5C1, Canada
| | - D H Betts
- Department of Physiology and Pharmacology, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, ON N6A 5C1, Canada
| | - A J LeBlanc
- Cardiovascular Innovation Institute, University of Louisville, Louisville, KY 40292, USA,Department of Cardiovascular and Thoracic Surgery, School of Medicine, University of Louisville, Louisville, KY 40292, USA
| | - D D Gutterman
- Department of Medicine, Medical College of Wisconsin, Milwaukee, WI 53226, USA,Cardiovascular Center, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - A M Beyer
- Address correspondence to A.M.B. (e-mail: )
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3
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Zakeri S, Aminian H, Sadeghi S, Esmaeilzadeh-Gharehdaghi E, Razmara E. Krüppel-like factors in bone biology. Cell Signal 2022; 93:110308. [PMID: 35301064 DOI: 10.1016/j.cellsig.2022.110308] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2022] [Revised: 03/07/2022] [Accepted: 03/09/2022] [Indexed: 12/27/2022]
Abstract
The krüppel-like factor (KLF) family is a group of zinc finger transcription factors and contributes to different cellular processes such as differentiation, proliferation, migration, and apoptosis. While different studies show the roles of this family in skeletal development-specifically in chondrocyte and osteocyte development and bone homeostasis-there are few reviews summarizing their importance. To fill this gap, this review discusses current knowledge on different functions of the KLF family during skeletal development, including their roles in stem cell maintenance and differentiation, cell apoptosis, and cell cycle. To understand the importance of the KLF family, we also review genotype-phenotype correlations in different animal models. We also discuss how KLF proteins function through different signaling pathways and display their paramount importance in skeletal development. To highlight their roles in cartilage- or bone-related cells, we also use single-cell RNA sequencing publicly available data on mouse hindlimb. We also challenge our knowledge of how the KLF family is epigenetically regulated-e.g., using DNA methylation, histone modifications, and noncoding RNAs-during chondrocyte and osteocyte development.
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Affiliation(s)
- Sina Zakeri
- Department of Veterinary Science, Faculty of Veterinary Medicine, Urmia University, Urmia, Iran
| | - Hesam Aminian
- Department of Biology, Faculty of Sciences, Nour Danesh Institute of Higher Education, Meymeh, Isfahan, Iran
| | - Soheila Sadeghi
- Department of Biology, Faculty of Basic Sciences, Sanandaj Branch, Islamic Azad University, Kurdistan, Iran
| | | | - Ehsan Razmara
- Department of Medical Genetics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.
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4
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Epigenetic features in regulation of telomeres and telomerase in stem cells. Emerg Top Life Sci 2021; 5:497-505. [PMID: 34486664 DOI: 10.1042/etls20200344] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 07/28/2021] [Accepted: 08/10/2021] [Indexed: 01/12/2023]
Abstract
The epigenetic nature of telomeres is still controversial and different human cell lines might show diverse histone marks at telomeres. Epigenetic modifications regulate telomere length and telomerase activity that influence telomere structure and maintenance. Telomerase is responsible for telomere elongation and maintenance and is minimally composed of the catalytic protein component, telomerase reverse transcriptase (TERT) and template forming RNA component, telomerase RNA (TERC). TERT promoter mutations may underpin some telomerase activation but regulation of the gene is not completely understood due to the complex interplay of epigenetic, transcriptional, and posttranscriptional modifications. Pluripotent stem cells (PSCs) can maintain an indefinite, immortal, proliferation potential through their endogenous telomerase activity, maintenance of telomere length, and a bypass of replicative senescence in vitro. Differentiation of PSCs results in silencing of the TERT gene and an overall reversion to a mortal, somatic cell phenotype. The precise mechanisms for this controlled transcriptional silencing are complex. Promoter methylation has been suggested to be associated with epigenetic control of telomerase regulation which presents an important prospect for understanding cancer and stem cell biology. Control of down-regulation of telomerase during differentiation of PSCs provides a convenient model for the study of its endogenous regulation. Telomerase reactivation has the potential to reverse tissue degeneration, drive repair, and form a component of future tissue engineering strategies. Taken together it becomes clear that PSCs provide a unique system to understand telomerase regulation fully and drive this knowledge forward into aging and therapeutic application.
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5
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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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6
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Subasri M, Shooshtari P, Watson AJ, Betts DH. Analysis of TERT Isoforms across TCGA, GTEx and CCLE Datasets. Cancers (Basel) 2021; 13:cancers13081853. [PMID: 33924498 PMCID: PMC8070023 DOI: 10.3390/cancers13081853] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 04/01/2021] [Accepted: 04/08/2021] [Indexed: 12/14/2022] Open
Abstract
Reactivation of the multi-subunit ribonucleoprotein telomerase is the primary telomere maintenance mechanism in cancer, but it is rate-limited by the enzymatic component, telomerase reverse transcriptase (TERT). While regulatory in nature, TERT alternative splice variant/isoform regulation and functions are not fully elucidated and are further complicated by their highly diverse expression and nature. Our primary objective was to characterize TERT isoform expression across 7887 neoplastic and 2099 normal tissue samples using The Cancer Genome Atlas (TCGA) and the Genotype-Tissue Expression Project (GTEx), respectively. We confirmed the global overexpression and splicing shift towards full-length TERT in neoplastic tissue. Stratifying by tissue type we found uncharacteristic TERT expression in normal brain tissue subtypes. Stratifying by tumor-specific subtypes, we detailed TERT expression differences potentially regulated by subtype-specific molecular characteristics. Focusing on β-deletion splicing regulation, we found the NOVA1 trans-acting factor to mediate alternative splicing in a cancer-dependent manner. Of relevance to future tissue-specific studies, we clustered cancer cell lines with tumors from related origin based on TERT isoform expression patterns. Taken together, our work has reinforced the need for tissue and tumour-specific TERT investigations, provided avenues to do so, and brought to light the current technical limitations of bioinformatic analyses of TERT isoform expression.
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Affiliation(s)
- Mathushan Subasri
- Department of Physiology and Pharmacology, The University of Western Ontario, London, ON N6A 5C1, Canada; (M.S.); (A.J.W.)
| | - Parisa Shooshtari
- Ontario Institute for Cancer Research, Toronto, ON M5G 0A3, Canada;
- Department of Pathology and Laboratory Medicine, The University of Western Ontario, London, ON N6A 5C1, Canada
- Department of Computer Science, The University of Western Ontario, London, ON N6A 5C1, Canada
- The Children’s Health Research Institute—Lawson Health Research Institute, London, ON N6C 2R5, Canada
| | - Andrew J. Watson
- Department of Physiology and Pharmacology, The University of Western Ontario, London, ON N6A 5C1, Canada; (M.S.); (A.J.W.)
- The Children’s Health Research Institute—Lawson Health Research Institute, London, ON N6C 2R5, Canada
- Department of Obstetrics and Gynaecology, The University of Western Ontario, London, ON N6A 5C1, Canada
| | - Dean H. Betts
- Department of Physiology and Pharmacology, The University of Western Ontario, London, ON N6A 5C1, Canada; (M.S.); (A.J.W.)
- The Children’s Health Research Institute—Lawson Health Research Institute, London, ON N6C 2R5, Canada
- Department of Obstetrics and Gynaecology, The University of Western Ontario, London, ON N6A 5C1, Canada
- Correspondence: ; Tel.: +1-519-661-2111 (ext. 83786)
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7
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Nakamura N, Shi X, Darabi R, Li Y. Hypoxia in Cell Reprogramming and the Epigenetic Regulations. Front Cell Dev Biol 2021; 9:609984. [PMID: 33585477 PMCID: PMC7876330 DOI: 10.3389/fcell.2021.609984] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 01/06/2021] [Indexed: 12/19/2022] Open
Abstract
Cellular reprogramming is a fundamental topic in the research of stem cells and molecular biology. It is widely investigated and its understanding is crucial for learning about different aspects of development such as cell proliferation, determination of cell fate and stem cell renewal. Other factors involved during development include hypoxia and epigenetics, which play major roles in the development of tissues and organs. This review will discuss the involvement of hypoxia and epigenetics in the regulation of cellular reprogramming and how interplay between each factor can contribute to different cellular functions as well as tissue regeneration.
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Affiliation(s)
- Nariaki Nakamura
- Department of Orthopaedic Surgery, and Biomedical Engineering, Homer Stryker M.D. School of Medicine, Western Michigan University, Kalamazoo, MI, United States
| | - Xiaobing Shi
- Center for Epigenetics, Van Andel Research Institute, Grand Rapids, MI, United States
| | - Radbod Darabi
- The Center for Stem Cell and Regenerative Medicine (CSCRM), Brown Foundation Institute of Molecular Medicine for the Prevention of Human Diseases (IMM), Houston, TX, United States
| | - Yong Li
- Department of Orthopaedic Surgery, and Biomedical Engineering, Homer Stryker M.D. School of Medicine, Western Michigan University, Kalamazoo, MI, United States
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8
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Vysotskaya OV, Glukhov AI, Semochkina YP, Gordeev SA, Moskaleva EY. [Telomerase activity, mTert gene expression and the telomere length in mouse mesenchymal stem cells in the late period after γ- and γ,n-irradiation and in the tumors developed from these cells]. BIOMEDIT︠S︡INSKAI︠A︡ KHIMII︠A︡ 2020; 66:265-273. [PMID: 32588833 DOI: 10.18097/pbmc20206603265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
In proliferating normal and tumor cells, the telomere length (TL) is maintained by high telomerase activity (TA). In the absence of TA the TL maintenance involves a mechanism of alternative lengthening of telomeres (ALT). The aim of this study was to investigate the level of TA, the mTert expression and TL in cultured normal and transformed by γ- and γ,n-irradiation mesenchymal stem cells (MSCs) from mouse bone marrow, in sarcomas that developed after the transplantation of these cells into syngeneic mice, and in fibrosarcoma cell lines obtained from these tumors to find out the role of AT or ALT in maintaining TL in these cells. During prolonged cultivation of normal and transformed under the influence of γ- (1 Gy and 6 Gy) and γ,n-irradiation (0.05 Gy, 0.5 Gy, and 2 Gy) MSCs from mouse bone marrow, a decrease in TA was detected in irradiated cells. Even deeper decrease in TA was found in sarcomas developed after administration of transformed MSCs to syngeneic mice and in fibrosarcoma cell lines isolated from these tumors in which TA was either absent or was found to be at a very low level. TL in three of the four lines obtained was halved compared to the initial MSCs. With absent or low TA and reduced TL, the cells of all the obtained fibrosarcoma lines successfully proliferated without signs of a change in survival. The mechanism of telomere maintainance in fibrosarcoma cell lines in the absence of TA needs further investigation and it can be assumed that it is associated with the use of the ALT. The detected decrease or absence of TA in transformed under the action of irradiation MSCs with the preservation or even an increase in the telomerase gene expression may be associated with the formation of inactive splicing variants, and requires further study. The obtained lines of transformed MSCs and fibrosarcomas with TA and without the activity of this enzyme can be a useful model for studying the efficacy of TA and ALT inhibitors in vitro and in vivo.
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Affiliation(s)
| | - A I Glukhov
- Faculty of Biology, Moscow State University, Moscow, Russia; Sechenov University, Moscow, Russia
| | | | - S A Gordeev
- Faculty of Biology, Moscow State University, Moscow, Russia
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9
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Farina AR, Cappabianca L, Sebastiano M, Zelli V, Guadagni S, Mackay AR. Hypoxia-induced alternative splicing: the 11th Hallmark of Cancer. J Exp Clin Cancer Res 2020; 39:110. [PMID: 32536347 PMCID: PMC7294618 DOI: 10.1186/s13046-020-01616-9] [Citation(s) in RCA: 67] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 06/03/2020] [Indexed: 12/16/2022] Open
Abstract
Hypoxia-induced alternative splicing is a potent driving force in tumour pathogenesis and progression. In this review, we update currents concepts of hypoxia-induced alternative splicing and how it influences tumour biology. Following brief descriptions of tumour-associated hypoxia and the pre-mRNA splicing process, we review the many ways hypoxia regulates alternative splicing and how hypoxia-induced alternative splicing impacts each individual hallmark of cancer. Hypoxia-induced alternative splicing integrates chemical and cellular tumour microenvironments, underpins continuous adaptation of the tumour cellular microenvironment responsible for metastatic progression and plays clear roles in oncogene activation and autonomous tumour growth, tumor suppressor inactivation, tumour cell immortalization, angiogenesis, tumour cell evasion of programmed cell death and the anti-tumour immune response, a tumour-promoting inflammatory response, adaptive metabolic re-programming, epithelial to mesenchymal transition, invasion and genetic instability, all of which combine to promote metastatic disease. The impressive number of hypoxia-induced alternative spliced protein isoforms that characterize tumour progression, classifies hypoxia-induced alternative splicing as the 11th hallmark of cancer, and offers a fertile source of potential diagnostic/prognostic markers and therapeutic targets.
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Affiliation(s)
- Antonietta Rosella Farina
- Department of Applied Clinical and Biotechnological Sciences, University of L’Aquila, 67100 L’Aquila, Italy
| | - Lucia Cappabianca
- Department of Applied Clinical and Biotechnological Sciences, University of L’Aquila, 67100 L’Aquila, Italy
| | - Michela Sebastiano
- Department of Applied Clinical and Biotechnological Sciences, University of L’Aquila, 67100 L’Aquila, Italy
| | - Veronica Zelli
- Department of Applied Clinical and Biotechnological Sciences, University of L’Aquila, 67100 L’Aquila, Italy
| | - Stefano Guadagni
- Department of Applied Clinical and Biotechnological Sciences, University of L’Aquila, 67100 L’Aquila, Italy
| | - Andrew Reay Mackay
- Department of Applied Clinical and Biotechnological Sciences, University of L’Aquila, 67100 L’Aquila, Italy
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Nemirovich-Danchenko NM, Khodanovich MY. Telomerase Gene Editing in the Neural Stem Cells in vivo as a Possible New Approach against Brain Aging. RUSS J GENET+ 2020. [DOI: 10.1134/s1022795420040092] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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11
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Wang X, Giusti A, Ny A, de Witte PA. Nephrotoxic Effects in Zebrafish after Prolonged Exposure to Aristolochic Acid. Toxins (Basel) 2020; 12:toxins12040217. [PMID: 32235450 PMCID: PMC7232444 DOI: 10.3390/toxins12040217] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Revised: 03/24/2020] [Accepted: 03/26/2020] [Indexed: 12/19/2022] Open
Abstract
With the aim to explore the possibility to generate a zebrafish model of renal fibrosis, in this study the fibrogenic renal effect of aristolochic acid I (AAI) after immersion was assessed. This compound is highly nephrotoxic able to elicit renal fibrosis after exposure of rats and humans. Our results reveal that larval zebrafish at 15 days dpf (days post-fertilization) exposed for 8 days to 0.5 µM AAI showed clear signs of AKI (acute kidney injury). The damage resulted in the relative loss of the functional glomerular filtration barrier. Conversely, we did not observe any deposition of collagen, nor could we immunodetect α-SMA, a hallmark of myofibroblasts, in the tubules. In addition, no increase in gene expression of fibrogenesis biomarkers after whole animal RNA extraction was found. As zebrafish have a high capability for tissue regeneration possibly impeding fibrogenic processes, we also used a tert−/− zebrafish line exhibiting telomerase deficiency and impaired tissue homeostasis. AAI-treated tert−/− larvae displayed an increased sensitivity towards 0.5 µM AAI. Importantly, after AAI treatment a mild collagen deposition could be found in the tubules. The outcome implies that sustained AKI induced by nephrotoxic compounds combined with defective tert−/− stem cells can produce a fibrotic response.
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12
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Ségal-Bendirdjian E, Geli V. Non-canonical Roles of Telomerase: Unraveling the Imbroglio. Front Cell Dev Biol 2019; 7:332. [PMID: 31911897 PMCID: PMC6914764 DOI: 10.3389/fcell.2019.00332] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Accepted: 11/27/2019] [Indexed: 12/11/2022] Open
Abstract
Telomerase plays a critical role in stem cell function and tissue regeneration that depends on its ability to elongate telomeres. For nearly two decades, it turned out that TERT regulates a broad spectrum of functions including signal transduction, gene expression regulation, and protection against oxidative damage that are independent of its telomere elongation activity. These conclusions that were mainly obtained in cell lines overexpressing telomerase were further strengthened by in vivo models of ectopic expression of telomerase or models of G1 TERT knockout mice without detectable telomere dysfunction. However, the later models were questioned due to the presence of aberrantly shortened telomere in the germline of the parents TERT+/- that were used to create the G1 TERT -/- mice. The physiological relevance of the functions associated with overexpressed telomerase raised also some concerns due to artifactual situations and localizations and complications to quantify the level of TERT. Another concern with non-canonical functions of TERT was the difficulty to separate a direct TERT-related function from secondary effects. Despite these concerns, more and more evidence accumulates for non-canonical roles of telomerase that are non-obligatory extra-telomeric. Here, we review these non-canonical roles of the TERT subunit of telomerase. Also, we emphasize recent results that link TERT to mitochondria and protection to reactive oxygen species suggesting a protective role of TERT in neurons. Throughout this review, we dissect some controversies regarding the non-canonical functions of telomerase and provide some insights to explain these discrepancies. Finally, we discuss the importance of understanding these alternative functions of telomerase for the development of anticancer strategies.
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Affiliation(s)
- Evelyne Ségal-Bendirdjian
- INSERM UMR-S 1124, Team: Cellular Homeostasis, Cancer and Therapies, INSERM US36, CNRS UMS 2009, BioMedTech Facilities, Université de Paris, Paris, France
| | - Vincent Geli
- Marseille Cancer Research Center, U1068 INSERM, UMR 7258 CNRS, Aix Marseille University, Institut Paoli-Calmettes, Equipe labellisée Ligue, Marseille, France
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13
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Zhao S, Wang F, Liu L. Alternative Lengthening of Telomeres (ALT) in Tumors and Pluripotent Stem Cells. Genes (Basel) 2019; 10:genes10121030. [PMID: 31835618 PMCID: PMC6947546 DOI: 10.3390/genes10121030] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 11/28/2019] [Accepted: 12/02/2019] [Indexed: 12/22/2022] Open
Abstract
A telomere consists of repeated DNA sequences (TTAGGG)n as part of a nucleoprotein structure at the end of the linear chromosome, and their progressive shortening induces DNA damage response (DDR) that triggers cellular senescence. The telomere can be maintained by telomerase activity (TA) in the majority of cancer cells (particularly cancer stem cells) and pluripotent stem cells (PSCs), which exhibit unlimited self-proliferation. However, some cells, such as telomerase-deficient cancer cells, can add telomeric repeats by an alternative lengthening of the telomeres (ALT) pathway, showing telomere length heterogeneity. In this review, we focus on the mechanisms of the ALT pathway and potential clinical implications. We also discuss the characteristics of telomeres in PSCs, thereby shedding light on the therapeutic significance of telomere length regulation in age-related diseases and regenerative medicine.
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Affiliation(s)
- Shuang Zhao
- College of Life Sciences, Nankai University, Tianjin 300071, China;
- State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin 300071, China
| | - Feng Wang
- Department of Genetics, School of Basic Medical Sciences, Tianjin Medical University, Tianjin 300070, China;
| | - Lin Liu
- College of Life Sciences, Nankai University, Tianjin 300071, China;
- State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin 300071, China
- Correspondence:
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14
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Chung SS, Dutta P, Chard N, Wu Y, Chen QH, Chen G, Vadgama J. A novel curcumin analog inhibits canonical and non-canonical functions of telomerase through STAT3 and NF-κB inactivation in colorectal cancer cells. Oncotarget 2019; 10:4516-4531. [PMID: 31360301 PMCID: PMC6642039 DOI: 10.18632/oncotarget.27000] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Accepted: 05/20/2019] [Indexed: 12/12/2022] Open
Abstract
Curcumin is a biologically active polyphenol that exists in Indian spice turmeric. It has been reported that curcumin exerted anti-inflammatory, anti-oxidant and anti-cancer effects in numerous in vitro and in vivo studies. However, it is not well-understood the molecular mechanism of curcumin for the cancer stem cells and telomerase in colorectal cancer. In this study, compound 19, a nitrogen-containing curcumin analog, was used to treat human colorectal cancer cells. Compound 19 showed a greater anti-proliferative activity than curcumin while displayed no significant toxicity toward normal human colon epithelial cells. Compound 19 exerted anti-inflammatory activities by deactivating STAT3 and NF-κB. In cancer stem cell populations, CD44, Oct-4 and ALDHA1 expressions were abolished upon treating with compound 19. Cancer stem cell biomarkers CD51 and CD133 positive populations were reduced and telomerase activities were decreased with the reduced STAT3 binding to hTERT promoters. This means compound 19 dually inhibits canonical and non-canonical functions of telomerase. Furthermore, compound 19 treatments induced cell cycle arrest at G1 phase and apoptosis. Human apoptosis-related array screening revealed that activated caspase 3, catalase, clusterin and cytochrome C led to apoptosis. Taken together, our data suggest that compound 19 can be a novel therapeutic agent for metastatic colorectal cancer by concurrently targeting STAT3 and NF-κB signaling pathways.
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Affiliation(s)
- Seyung S Chung
- Division of Cancer Research and Training, Charles R. Drew University of Medicine and Science, Los Angeles, California 90059, USA.,David Geffen School of Medicine, UCLA, Los Angeles, California 90095, USA
| | - Pranabananda Dutta
- Division of Cancer Research and Training, Charles R. Drew University of Medicine and Science, Los Angeles, California 90059, USA
| | - Nathaniel Chard
- Division of Cancer Research and Training, Charles R. Drew University of Medicine and Science, Los Angeles, California 90059, USA
| | - Yong Wu
- Division of Cancer Research and Training, Charles R. Drew University of Medicine and Science, Los Angeles, California 90059, USA.,David Geffen School of Medicine, UCLA, Los Angeles, California 90095, USA
| | - Qiao-Hong Chen
- Department of Chemistry, California State University at Fresno, Fresno, California 93740, USA
| | - Guanglin Chen
- Department of Chemistry, California State University at Fresno, Fresno, California 93740, USA
| | - Jaydutt Vadgama
- Division of Cancer Research and Training, Charles R. Drew University of Medicine and Science, Los Angeles, California 90059, USA.,Jonsson Comprehensive Cancer Center, UCLA, Los Angeles, California 90095, USA.,David Geffen School of Medicine, UCLA, Los Angeles, California 90095, USA
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15
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Samiec M, Romanek J, Lipiński D, Opiela J. Expression of pluripotency-related genes is highly dependent on trichostatin A-assisted epigenomic modulation of porcine mesenchymal stem cells analysed for apoptosis and subsequently used for generating cloned embryos. Anim Sci J 2019; 90:1127-1141. [PMID: 31298467 DOI: 10.1111/asj.13260] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Revised: 04/30/2019] [Accepted: 06/04/2019] [Indexed: 12/13/2022]
Abstract
The present study sought to examine whether trichostatin A (TSA)-assisted epigenetic transformation of porcine bone marrow (BM)-derived mesenchymal stem cells (BM-MSCs) affects the transcriptional activities of pluripotency-related genes (Oct4, Nanog, c-Myc, Sox2 and Rex1), multipotent stemness-related gene (Nestin) and anti-apoptotic/anti-senescence-related gene (Survivin). Epigenetically transformed or non-transformed BM-MSCs that had been transcriptionally profiled by qRT-PCR and had been analysed for different stages of apoptosis progression provided a source of nuclear donor cells for the in vitro production of cloned pig embryos. TSA-mediated epigenomic modulation has been found to enhance the multipotency extent, stemness and intracellular anti-ageing properties of porcine BM-MSCs. This has been confirmed by the relative abundances for Nanog, c-Myc Rex1, Sox2 and Survivin mRNAs in TSA-exposed BM-MSCs that turned out to be significantly higher than those of TSA-unexposed BM-MSCs. Additionally, TSA-assisted epigenomic modulation of BM-MSCs did not impact the caspase-8 activity, Bax protein expression and the incidence of TUNEL-positive cells. In conclusion, the considerably elevated quantitative profiles of Sox2, Rex1, c-Myc, Nanog and Survivin mRNA transcripts seem to trigger improved reprogrammability of TSA-treated BM-MSC nuclei in cloned pig embryos that thereby displayed remarkably increased blastocyst formation rates as compared to those noticed for embryos derived from TSA-untreated BM-MSCs.
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Affiliation(s)
- Marcin Samiec
- Department of Reproductive Biotechnology and Cryoconservation, National Research Institute of Animal Production, Balice n. Kraków, Poland
| | - Joanna Romanek
- Department of Reproductive Biotechnology and Cryoconservation, National Research Institute of Animal Production, Balice n. Kraków, Poland
| | - Daniel Lipiński
- Department of Biochemistry and Biotechnology, Poznań University of Life Sciences, Poznań, Poland
| | - Jolanta Opiela
- Department of Reproductive Biotechnology and Cryoconservation, National Research Institute of Animal Production, Balice n. Kraków, Poland
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16
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A telomerase with novel non-canonical roles: TERT controls cellular aggregation and tissue size in Dictyostelium. PLoS Genet 2019; 15:e1008188. [PMID: 31237867 PMCID: PMC6592521 DOI: 10.1371/journal.pgen.1008188] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Accepted: 05/10/2019] [Indexed: 11/19/2022] Open
Abstract
Telomerase, particularly its main subunit, the reverse transcriptase, TERT, prevents DNA erosion during eukaryotic chromosomal replication, but also has poorly understood non-canonical functions. Here, in the model social amoeba Dictyostelium discoideum, we show that the protein encoded by tert has telomerase-like motifs, and regulates, non-canonically, important developmental processes. Expression levels of wild-type (WT) tert were biphasic, peaking at 8 and 12 h post-starvation, aligning with developmental events, such as the initiation of streaming (~7 h) and mound formation (~10 h). In tert KO mutants, however, aggregation was delayed until 16 h. Large, irregular streams formed, then broke up, forming small mounds. The mound-size defect was not induced when a KO mutant of countin (a master size-regulating gene) was treated with TERT inhibitors, but anti-countin antibodies did rescue size in the tert KO. Although, conditioned medium (CM) from countin mutants failed to rescue size in the tert KO, tert KO CM rescued the countin KO phenotype. These and additional observations indicate that TERT acts upstream of smlA/countin: (i) the observed expression levels of smlA and countin, being respectively lower and higher (than WT) in the tert KO; (ii) the levels of known size-regulation intermediates, glucose (low) and adenosine (high), in the tert mutant, and the size defect's rescue by supplemented glucose or the adenosine-antagonist, caffeine; (iii) the induction of the size defect in the WT by tert KO CM and TERT inhibitors. The tert KO's other defects (delayed aggregation, irregular streaming) were associated with changes to cAMP-regulated processes (e.g. chemotaxis, cAMP pulsing) and their regulatory factors (e.g. cAMP; acaA, carA expression). Overexpression of WT tert in the tert KO rescued these defects (and size), and restored a single cAMP signaling centre. Our results indicate that TERT acts in novel, non-canonical and upstream ways, regulating key developmental events in Dictyostelium.
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17
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Li Q, Zhou X, Fang Z, Pan Z. Effect of STC2 gene silencing on colorectal cancer cells. Mol Med Rep 2019; 20:977-984. [PMID: 31173256 PMCID: PMC6625197 DOI: 10.3892/mmr.2019.10332] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Accepted: 03/27/2019] [Indexed: 02/06/2023] Open
Abstract
Stanniocalcin 2 (STC2), a secretory glycoprotein hormone, regulates many biological processes including cell proliferation, apoptosis, tumorigenesis and atherosclerosis. However, the effect of STC2 on proliferation, migration and epithelial-mesenchymal transition (EMT) progression in human colorectal cancer (CRC) cells remains poorly understood. The expression level of STC2 was determined by quantitative real-time polymerase chain reaction (qPCR) and western blot analysis. Cell Counting Kit-8 (CCK-8) was used to detect the viability of SW480 cells. The invasion and migration of cells were identified by wound healing and Transwell assays. The mRNA and protein expression levels of β-catenin, matrix metalloproteinase (MMP)-2, MMP-9, E-cadherin and vimentin were assessed by qPCR and western blot analysis. In the present study, it was demonstrated that STC2 was highly expressed in the CRC cell lines. After silencing of STC2, the cell viability, migration and invasion were significantly reduced. Silencing of STC2 in the CRC Sw480 cells increased the expression of E-cadherin and decreased the expression of vimentin, MMP-2 and MMP-9, compared to those in the normal and empty vector group. Furthermore, the expression of β-catenin in the STC2 gene silenced group was suppressed, and the expression of β-catenin was reversed by Wnt activator, SB216763. These results demonstrated that STC2 participates in the development and progression of CRC by promoting CRC cell proliferation, survival and migration and activating the Wnt/β-catenin signaling pathway.
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Affiliation(s)
- Qianyuan Li
- Department of Anorectal Surgery, The First Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou, Zhejiang 310006, P.R. China
| | - Xiukou Zhou
- Department of Anorectal Surgery, The First Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou, Zhejiang 310006, P.R. China
| | - Zhengyu Fang
- Department of Anorectal Surgery, The First Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou, Zhejiang 310006, P.R. China
| | - Zhiyun Pan
- Department of Anorectal Surgery, The First Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou, Zhejiang 310006, P.R. China
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18
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Insights into Telomerase/hTERT Alternative Splicing Regulation Using Bioinformatics and Network Analysis in Cancer. Cancers (Basel) 2019; 11:cancers11050666. [PMID: 31091669 PMCID: PMC6562651 DOI: 10.3390/cancers11050666] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2019] [Revised: 05/10/2019] [Accepted: 05/13/2019] [Indexed: 01/08/2023] Open
Abstract
The reactivation of telomerase in cancer cells remains incompletely understood. The catalytic component of telomerase, hTERT, is thought to be the limiting component in cancer cells for the formation of active enzymes. hTERT gene expression is regulated at several levels including chromatin, DNA methylation, transcription factors, and RNA processing events. Of these regulatory events, RNA processing has received little attention until recently. RNA processing and alternative splicing regulation have been explored to understand how hTERT is regulated in cancer cells. The cis- and trans-acting factors that regulate the alternative splicing choice of hTERT in the reverse transcriptase domain have been investigated. Further, it was discovered that the splicing factors that promote the production of full-length hTERT were also involved in cancer cell growth and survival. The goals are to review telomerase regulation via alternative splicing and the function of hTERT splicing variants and to point out how bioinformatics approaches are leading the way in elucidating the networks that regulate hTERT splicing choice and ultimately cancer growth.
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Shishkin SS, Kovalev LI, Pashintseva NV, Kovaleva MA, Lisitskaya K. Heterogeneous Nuclear Ribonucleoproteins Involved in the Functioning of Telomeres in Malignant Cells. Int J Mol Sci 2019; 20:ijms20030745. [PMID: 30744200 PMCID: PMC6387250 DOI: 10.3390/ijms20030745] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Revised: 01/31/2019] [Accepted: 02/04/2019] [Indexed: 12/12/2022] Open
Abstract
Heterogeneous nuclear ribonucleoproteins (hnRNPs) are structurally and functionally distinct proteins containing specific domains and motifs that enable the proteins to bind certain nucleotide sequences, particularly those found in human telomeres. In human malignant cells (HMCs), hnRNP-A1-the most studied hnRNP-is an abundant multifunctional protein that interacts with telomeric DNA and affects telomerase function. In addition, it is believed that other hnRNPs in HMCs may also be involved in the maintenance of telomere length. Accordingly, these proteins are considered possible participants in the processes associated with HMC immortalization. In our review, we discuss the results of studies on different hnRNPs that may be crucial to solving molecular oncological problems and relevant to further investigations of these proteins in HMCs.
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Affiliation(s)
- Sergey S Shishkin
- Laboratory of Biomedical Research, Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, Leninsky Prospekt, 33, bld. 2, 119071 Moscow, Russia.
| | - Leonid I Kovalev
- Laboratory of Biomedical Research, Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, Leninsky Prospekt, 33, bld. 2, 119071 Moscow, Russia.
| | - Natalya V Pashintseva
- Laboratory of Biomedical Research, Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, Leninsky Prospekt, 33, bld. 2, 119071 Moscow, Russia.
| | - Marina A Kovaleva
- Laboratory of Biomedical Research, Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, Leninsky Prospekt, 33, bld. 2, 119071 Moscow, Russia.
| | - Ksenia Lisitskaya
- Laboratory of Biomedical Research, Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, Leninsky Prospekt, 33, bld. 2, 119071 Moscow, Russia.
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20
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Romaniuk A, Paszel-Jaworska A, Totoń E, Lisiak N, Hołysz H, Królak A, Grodecka-Gazdecka S, Rubiś B. The non-canonical functions of telomerase: to turn off or not to turn off. Mol Biol Rep 2018; 46:1401-1411. [PMID: 30448892 DOI: 10.1007/s11033-018-4496-x] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Accepted: 11/12/2018] [Indexed: 12/19/2022]
Abstract
Telomerase is perceived as an immortality enzyme that enables passing the Hayflick limit. Its main function is telomere restoration but only in a limited group of cells, including cancer cells. Since it is found in a vast majority of cancer cells, it became a natural target for cancer therapy. However, it has much more functions than just altering the metabolism of telomeres-it also reveals numerous so-called non-canonical functions. Thus, a question arises whether it is always beneficial to turn it off when planning a cancer strategy and considering potential side effects? The purpose of this review is to discuss some of the recent discoveries about telomere-independent functions of telomerase in the context of cancer therapy and potential side effects.
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Affiliation(s)
- Aleksandra Romaniuk
- Department of Clinical Chemistry and Molecular Diagnostics, Poznan University of Medical Sciences, 49 Przybyszewskiego St., 60-355, Poznań, Poland
| | - Anna Paszel-Jaworska
- Department of Clinical Chemistry and Molecular Diagnostics, Poznan University of Medical Sciences, 49 Przybyszewskiego St., 60-355, Poznań, Poland
| | - Ewa Totoń
- Department of Clinical Chemistry and Molecular Diagnostics, Poznan University of Medical Sciences, 49 Przybyszewskiego St., 60-355, Poznań, Poland
| | - Natalia Lisiak
- Department of Clinical Chemistry and Molecular Diagnostics, Poznan University of Medical Sciences, 49 Przybyszewskiego St., 60-355, Poznań, Poland
| | - Hanna Hołysz
- Department of Clinical Chemistry and Molecular Diagnostics, Poznan University of Medical Sciences, 49 Przybyszewskiego St., 60-355, Poznań, Poland
| | - Anna Królak
- Department of Clinical Chemistry and Molecular Diagnostics, Poznan University of Medical Sciences, 49 Przybyszewskiego St., 60-355, Poznań, Poland
| | | | - Błażej Rubiś
- Department of Clinical Chemistry and Molecular Diagnostics, Poznan University of Medical Sciences, 49 Przybyszewskiego St., 60-355, Poznań, Poland.
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21
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Biray Avci C, Dogan F, Ozates Ay NP, Goker Bagca B, Abbaszadeh Z, Gunduz C. Effects of telomerase inhibitor on epigenetic chromatin modification enzymes in malignancies. J Cell Biochem 2018; 119:9817-9824. [DOI: 10.1002/jcb.27301] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Accepted: 06/27/2018] [Indexed: 12/15/2022]
Affiliation(s)
- Cigir Biray Avci
- Department of Medical Biology Ege University Medical School Izmir Turkey
| | - Fatma Dogan
- Department of Medical Biology Ege University Medical School Izmir Turkey
| | | | - Bakiye Goker Bagca
- Department of Medical Biology Ege University Medical School Izmir Turkey
| | - Zeka Abbaszadeh
- Department of Medical Biology Ege University Medical School Izmir Turkey
| | - Cumhur Gunduz
- Department of Medical Biology Ege University Medical School Izmir Turkey
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22
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Abstract
Single-cell RNAseq and alternative splicing studies have recently become two of the most prominent applications of RNAseq. However, the combination of both is still challenging, and few research efforts have been dedicated to the intersection between them. Cell-level insight on isoform expression is required to fully understand the biology of alternative splicing, but it is still an open question to what extent isoform expression analysis at the single-cell level is actually feasible. Here, we establish a set of four conditions that are required for a successful single-cell-level isoform study and evaluate how these conditions are met by these technologies in published research.
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Affiliation(s)
- Ángeles Arzalluz-Luque
- Genomics of Gene Expression Laboratory, Centro de Investigación Principe Felipe (CIPF), 46012, Valencia, Spain
| | - Ana Conesa
- Genomics of Gene Expression Laboratory, Centro de Investigación Principe Felipe (CIPF), 46012, Valencia, Spain.
- Department of Microbiology and Cell Science, Institute for Food and Agricultural Sciences, Genetics Institute, University of Florida, Gainesville, Florida, 32611, USA.
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23
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Activating the PGC-1 α/TERT Pathway by Catalpol Ameliorates Atherosclerosis via Modulating ROS Production, DNA Damage, and Telomere Function: Implications on Mitochondria and Telomere Link. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2018; 2018:2876350. [PMID: 30046372 PMCID: PMC6036816 DOI: 10.1155/2018/2876350] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/14/2018] [Accepted: 03/15/2018] [Indexed: 12/17/2022]
Abstract
Catalpol, an iridoid glucoside, has been found present in large quantities in the root of Rehmannia glutinosa L. and showed a strong antioxidant capacity in the previous study. In the present work, the protective effect of catalpol against AS via inhibiting oxidative stress, DNA damage, and telomere shortening was found in LDLr-/- mice. This study also shows that activation of the peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α)/telomerase reverse transcriptase (TERT) pathway, which is the new link between mitochondria and telomere, was involved in the protective effects of catalpol. Further, by using PGC-1α or TERT siRNA in oxLDL-treated macrophages, it is proved that catalpol reduced oxidative stress, telomere function, and related DNA damage at least partly through activating the PGC-1α/TERT pathway. Moreover, dual luciferase activity assay-validated catalpol directly enhanced PGC-1α promoter activity. In conclusion, our study revealed that the PGC-1α/TERT pathway might be a possible therapeutic target in AS and catalpol has highly favorable characteristics for the treatment of AS via modulating this pathway.
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Fu H, Tian CL, Ye X, Sheng X, Wang H, Liu Y, Liu L. Dynamics of Telomere Rejuvenation during Chemical Induction to Pluripotent Stem Cells. Stem Cell Reports 2018; 11:70-87. [PMID: 29861168 PMCID: PMC6066961 DOI: 10.1016/j.stemcr.2018.05.003] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Revised: 05/02/2018] [Accepted: 05/03/2018] [Indexed: 02/07/2023] Open
Abstract
Chemically induced pluripotent stem cells (CiPSCs) may provide an alternative and attractive source for stem cell-based therapy. Sufficient telomere lengths are critical for unlimited self-renewal and genomic stability of pluripotent stem cells. Dynamics and mechanisms of telomere reprogramming of CiPSCs remain elusive. We show that CiPSCs acquire telomere lengthening with increasing passages after clonal formation. Both telomerase activity and recombination-based mechanisms are involved in the telomere elongation. Telomere lengths strongly indicate the degree of reprogramming, pluripotency, and differentiation capacity of CiPSCs. Nevertheless, telomere damage and shortening occur at a late stage of lengthy induction, limiting CiPSC formation. We find that histone crotonylation induced by crotonic acid can activate two-cell genes, including Zscan4; maintain telomeres; and promote CiPSC generation. Crotonylation decreases the abundance of heterochromatic H3K9me3 and HP1α at subtelomeres and Zscan4 loci. Taken together, telomere rejuvenation links to reprogramming and pluripotency of CiPSCs. Crotonylation facilitates telomere maintenance and enhances chemically induced reprogramming to pluripotency. CiPSCs acquire telomere elongation after clonal formation with increasing passages Both telomerase and recombination mechanisms are involved in the telomere elongation Telomere damage and shortening can occur during late stage of lengthy induction Crotonylation activates Zscan4 and promotes telomere elongation and CiPSC induction
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Affiliation(s)
- Haifeng Fu
- State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin 300071, China; Department of Cell Biology and Genetics, College of Life Sciences, Key Laboratory of Bioactive Materials of Ministry of Education, Nankai University, Tianjin 300071, China
| | - Cheng-Lei Tian
- State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin 300071, China; Department of Cell Biology and Genetics, College of Life Sciences, Key Laboratory of Bioactive Materials of Ministry of Education, Nankai University, Tianjin 300071, China
| | - Xiaoying Ye
- State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin 300071, China; Department of Cell Biology and Genetics, College of Life Sciences, Key Laboratory of Bioactive Materials of Ministry of Education, Nankai University, Tianjin 300071, China
| | - Xiaoyan Sheng
- State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin 300071, China; Department of Cell Biology and Genetics, College of Life Sciences, Key Laboratory of Bioactive Materials of Ministry of Education, Nankai University, Tianjin 300071, China
| | - Hua Wang
- State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin 300071, China; Department of Cell Biology and Genetics, College of Life Sciences, Key Laboratory of Bioactive Materials of Ministry of Education, Nankai University, Tianjin 300071, China
| | - Yifei Liu
- Department of Obstetrics, Gynecology & Reproductive Sciences, Yale School of Medicine, New Haven, CT 06511, USA
| | - Lin Liu
- State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin 300071, China; Department of Cell Biology and Genetics, College of Life Sciences, Key Laboratory of Bioactive Materials of Ministry of Education, Nankai University, Tianjin 300071, China.
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25
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Tardaguila M, de la Fuente L, Marti C, Pereira C, Pardo-Palacios FJ, Del Risco H, Ferrell M, Mellado M, Macchietto M, Verheggen K, Edelmann M, Ezkurdia I, Vazquez J, Tress M, Mortazavi A, Martens L, Rodriguez-Navarro S, Moreno-Manzano V, Conesa A. SQANTI: extensive characterization of long-read transcript sequences for quality control in full-length transcriptome identification and quantification. Genome Res 2018; 28:gr.222976.117. [PMID: 29440222 PMCID: PMC5848618 DOI: 10.1101/gr.222976.117] [Citation(s) in RCA: 208] [Impact Index Per Article: 34.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Accepted: 01/08/2018] [Indexed: 01/15/2023]
Abstract
High-throughput sequencing of full-length transcripts using long reads has paved the way for the discovery of thousands of novel transcripts, even in well-annotated mammalian species. The advances in sequencing technology have created a need for studies and tools that can characterize these novel variants. Here, we present SQANTI, an automated pipeline for the classification of long-read transcripts that can assess the quality of data and the preprocessing pipeline using 47 unique descriptors. We apply SQANTI to a neuronal mouse transcriptome using Pacific Biosciences (PacBio) long reads and illustrate how the tool is effective in characterizing and describing the composition of the full-length transcriptome. We perform extensive evaluation of ToFU PacBio transcripts by PCR to reveal that an important number of the novel transcripts are technical artifacts of the sequencing approach and that SQANTI quality descriptors can be used to engineer a filtering strategy to remove them. Most novel transcripts in this curated transcriptome are novel combinations of existing splice sites, resulting more frequently in novel ORFs than novel UTRs, and are enriched in both general metabolic and neural-specific functions. We show that these new transcripts have a major impact in the correct quantification of transcript levels by state-of-the-art short-read-based quantification algorithms. By comparing our iso-transcriptome with public proteomics databases, we find that alternative isoforms are elusive to proteogenomics detection. SQANTI allows the user to maximize the analytical outcome of long-read technologies by providing the tools to deliver quality-evaluated and curated full-length transcriptomes.
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Affiliation(s)
- Manuel Tardaguila
- Department of Microbiology and Cell Science, Institute for Food and Agricultural Sciences, Genetics Institute, University of Florida, Gainesville, Florida 32611, USA
| | - Lorena de la Fuente
- Genomics of Gene Expression Laboratory, Centro de Investigaciones Principe Felipe (CIPF), 46012 Valencia, Spain
| | - Cristina Marti
- Genomics of Gene Expression Laboratory, Centro de Investigaciones Principe Felipe (CIPF), 46012 Valencia, Spain
| | - Cécile Pereira
- Department of Microbiology and Cell Science, Institute for Food and Agricultural Sciences, Genetics Institute, University of Florida, Gainesville, Florida 32611, USA
| | | | - Hector Del Risco
- Department of Microbiology and Cell Science, Institute for Food and Agricultural Sciences, Genetics Institute, University of Florida, Gainesville, Florida 32611, USA
| | - Marc Ferrell
- Department of Microbiology and Cell Science, Institute for Food and Agricultural Sciences, Genetics Institute, University of Florida, Gainesville, Florida 32611, USA
| | | | - Marissa Macchietto
- Department of Developmental and Cell Biology, University of California, Irvine, California 92617, USA
| | - Kenneth Verheggen
- VIB-UGent Center for Medical Biotechnology, VIB, B-9000 Ghent, Belgium
- Department of Biochemistry, Ghent University, B-9000 Ghent, Belgium
| | - Mariola Edelmann
- Department of Microbiology and Cell Science, Institute for Food and Agricultural Sciences, Genetics Institute, University of Florida, Gainesville, Florida 32611, USA
| | - Iakes Ezkurdia
- Centro Nacional de Investigaciones Cardiovasculares CNIC, 28029 Madrid, Spain
| | - Jesus Vazquez
- Centro Nacional de Investigaciones Cardiovasculares CNIC, 28029 Madrid, Spain
| | - Michael Tress
- Spanish National Cancer Research Centre (CNIO), 28029 Madrid, Spain
| | - Ali Mortazavi
- Department of Developmental and Cell Biology, University of California, Irvine, California 92617, USA
| | - Lennart Martens
- VIB-UGent Center for Medical Biotechnology, VIB, B-9000 Ghent, Belgium
- Department of Biochemistry, Ghent University, B-9000 Ghent, Belgium
| | - Susana Rodriguez-Navarro
- Gene Expression and mRNA Metabolism Laboratory, CSIC, IBV, 46010 Valencia, Spain
- Gene Expression and mRNA Metabolism Laboratory, CIPF, 46012 Valencia, Spain
| | | | - Ana Conesa
- Department of Microbiology and Cell Science, Institute for Food and Agricultural Sciences, Genetics Institute, University of Florida, Gainesville, Florida 32611, USA
- Genomics of Gene Expression Laboratory, Centro de Investigaciones Principe Felipe (CIPF), 46012 Valencia, Spain
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Dogan F, Biray Avci C. Correlation between telomerase and mTOR pathway in cancer stem cells. Gene 2018; 641:235-239. [DOI: 10.1016/j.gene.2017.09.072] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Revised: 09/14/2017] [Accepted: 09/26/2017] [Indexed: 12/17/2022]
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Wang P, Mokhtari R, Pedrosa E, Kirschenbaum M, Bayrak C, Zheng D, Lachman HM. CRISPR/Cas9-mediated heterozygous knockout of the autism gene CHD8 and characterization of its transcriptional networks in cerebral organoids derived from iPS cells. Mol Autism 2017; 8:11. [PMID: 28321286 PMCID: PMC5357816 DOI: 10.1186/s13229-017-0124-1] [Citation(s) in RCA: 167] [Impact Index Per Article: 23.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Accepted: 02/15/2017] [Indexed: 02/01/2023] Open
Abstract
BACKGROUND CHD8 (chromodomain helicase DNA-binding protein 8), which codes for a member of the CHD family of ATP-dependent chromatin-remodeling factors, is one of the most commonly mutated genes in autism spectrum disorders (ASD) identified in exome-sequencing studies. Loss of function mutations in the gene have also been found in schizophrenia (SZ) and intellectual disabilities and influence cancer cell proliferation. We previously reported an RNA-seq analysis carried out on neural progenitor cells (NPCs) and monolayer neurons derived from induced pluripotent stem (iPS) cells that were heterozygous for CHD8 knockout (KO) alleles generated using CRISPR-Cas9 gene editing. A significant number of ASD and SZ candidate genes were among those that were differentially expressed in a comparison of heterozygous KO lines (CHD8+/-) vs isogenic controls (CHD8+/-), including the SZ and bipolar disorder (BD) candidate gene TCF4, which was markedly upregulated in CHD8+/- neuronal cells. METHODS In the current study, RNA-seq was carried out on CHD8+/- and isogenic control (CHD8+/+) cerebral organoids, which are 3-dimensional structures derived from iPS cells that model the developing human telencephalon. RESULTS TCF4 expression was, again, significantly upregulated. Pathway analysis carried out on differentially expressed genes (DEGs) revealed an enrichment of genes involved in neurogenesis, neuronal differentiation, forebrain development, Wnt/β-catenin signaling, and axonal guidance, similar to our previous study on NPCs and monolayer neurons. There was also significant overlap in our CHD8+/- DEGs with those found in a transcriptome analysis carried out by another group using cerebral organoids derived from a family with idiopathic ASD. Remarkably, the top DEG in our respective studies was the non-coding RNA DLX6-AS1, which was markedly upregulated in both studies; DLX6-AS1 regulates the expression of members of the DLX (distal-less homeobox) gene family. DLX1 was also upregulated in both studies. DLX genes code for transcription factors that play a key role in GABAergic interneuron differentiation. Significant overlap was also found in a transcriptome study carried out by another group using iPS cell-derived neurons from patients with BD, a condition characterized by dysregulated WNT/β-catenin signaling in a subgroup of affected individuals. CONCLUSIONS Overall, the findings show that distinct ASD, SZ, and BD candidate genes converge on common molecular targets-an important consideration for developing novel therapeutics in genetically heterogeneous complex traits.
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Affiliation(s)
- Ping Wang
- Department of Genetics, Albert Einstein College of Medicine, 1300 Morris Park Ave, Bronx, NY USA
| | - Ryan Mokhtari
- Department of Psychiatry and Behavioral Sciences, Erciyes University School of Medicine, Kayseri, Turkey
| | - Erika Pedrosa
- Department of Psychiatry and Behavioral Sciences, Erciyes University School of Medicine, Kayseri, Turkey
| | - Michael Kirschenbaum
- Department of Psychiatry and Behavioral Sciences, Erciyes University School of Medicine, Kayseri, Turkey
| | - Can Bayrak
- Erciyes University School of Medicine, Kayseri, Turkey
| | - Deyou Zheng
- Department of Genetics, Albert Einstein College of Medicine, 1300 Morris Park Ave, Bronx, NY USA
- Department of Neurology, Albert Einstein College of Medicine, 1300 Morris Park Ave, Bronx, NY USA
- Department of Neuroscience, Albert Einstein College of Medicine, 1300 Morris Park Ave, Bronx, NY USA
| | - Herbert M. Lachman
- Department of Genetics, Albert Einstein College of Medicine, 1300 Morris Park Ave, Bronx, NY USA
- Department of Psychiatry and Behavioral Sciences, Erciyes University School of Medicine, Kayseri, Turkey
- Department of Neuroscience, Albert Einstein College of Medicine, 1300 Morris Park Ave, Bronx, NY USA
- Department of Medicine, Albert Einstein College of Medicine, 1300 Morris Park Ave, Bronx, NY USA
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Liu X, Wang Y, Chang G, Wang F, Wang F, Geng X. Alternative Splicing of hTERT Pre-mRNA: A Potential Strategy for the Regulation of Telomerase Activity. Int J Mol Sci 2017; 18:ijms18030567. [PMID: 28272339 PMCID: PMC5372583 DOI: 10.3390/ijms18030567] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2016] [Revised: 02/14/2017] [Accepted: 03/02/2017] [Indexed: 12/11/2022] Open
Abstract
The activation of telomerase is one of the key events in the malignant transition of cells, and the expression of human telomerase reverse transcriptase (hTERT) is indispensable in the process of activating telomerase. The pre-mRNA alternative splicing of hTERT at the post-transcriptional level is one of the mechanisms for the regulation of telomerase activity. Shifts in splicing patterns occur in the development, tumorigenesis, and response to diverse stimuli in a tissue-specific and cell type–specific manner. Despite the regulation of telomerase activity, the alternative splicing of hTERT pre-mRNA may play a role in other cellular functions. Modulating the mode of hTERT pre-mRNA splicing is providing a new precept of therapy for cancer and aging-related diseases. This review focuses on the patterns of hTERT pre-mRNA alternative splicing and their biological functions, describes the potential association between the alternative splicing of hTERT pre-mRNA and telomerase activity, and discusses the possible significance of the alternative splicing of the hTERT pre-mRNA in the diagnosis, therapy, and prognosis of cancer and aging-related diseases.
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Affiliation(s)
- Xuewen Liu
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Tianjin Medical University, Tianjin 300070, China.
- Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), Tianjin Medical University, Tianjin 300070, China.
| | - Yuchuan Wang
- Tianjin Key Laboratory of Ophthalmology and Visual Science, Tianjin Eye Hospital, Tianjin 300070, China.
- Clinical College of Ophthalmology, Tianjin Medical University, Tianjin 300070, China.
| | - Guangming Chang
- Department of Clinical Laboratory, General Hospital, Tianjin Medical University, Tianjin 300070, China.
| | - Feng Wang
- Department of Genetics, Tianjin Medical University, Tianjin 300070, China.
| | - Fei Wang
- Department of Neurology, General Hospital, Tianjin Medical University, Tianjin 300052, China.
| | - Xin Geng
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Tianjin Medical University, Tianjin 300070, China.
- Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), Tianjin Medical University, Tianjin 300070, China.
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