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Taheri M, Ghafouri-Fard S, Najafi S, Kallenbach J, Keramatfar E, Atri Roozbahani G, Heidari Horestani M, Hussen BM, Baniahmad A. Hormonal regulation of telomerase activity and hTERT expression in steroid-regulated tissues and cancer. Cancer Cell Int 2022; 22:258. [PMID: 35974340 PMCID: PMC9380309 DOI: 10.1186/s12935-022-02678-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Accepted: 08/05/2022] [Indexed: 11/10/2022] Open
Abstract
Naturally, in somatic cells chromosome ends (telomeres) shorten during each cell division. This process ensures to limit proliferation of somatic cells to avoid malignant proliferation; however, it leads to proliferative senescence. Telomerase contains the reverse transcriptase TERT, which together with the TERC component, is responsible for protection of genome integrity by preventing shortening of telomeres through adding repetitive sequences. In addition, telomerase has non-telomeric function and supports growth factor independent growth. Unlike somatic cells, telomerase is detectable in stem cells, germ line cells, and cancer cells to support self-renewal and expansion. Elevated telomerase activity is reported in almost all of human cancers. Increased expression of hTERT gene or its reactivation is required for limitless cellular proliferation in immortal malignant cells. In hormonally regulated tissues as well as in prostate, breast and endometrial cancers, telomerase activity and hTERT expression are under control of steroid sex hormones and growth factors. Also, a number of hormones and growth factors are known to play a role in the carcinogenesis via regulation of hTERT levels or telomerase activity. Understanding the role of hormones in interaction with telomerase may help finding therapeutical targets for anticancer strategies. In this review, we outline the roles and functions of several steroid hormones and growth factors in telomerase regulation, particularly in hormone regulated cancers such as prostate, breast and endometrial cancer.
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Affiliation(s)
- Mohammad Taheri
- Urology and Nephrology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran.,Institute of Human Genetics, Jena University Hospital, 07740, Jena, Germany
| | - Soudeh Ghafouri-Fard
- Department of Medical Genetics, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Sajad Najafi
- Department of Medical Biotechnology, School of Advanced Technologies in Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Julia Kallenbach
- Institute of Human Genetics, Jena University Hospital, 07740, Jena, Germany
| | - Elmira Keramatfar
- Institute of Human Genetics, Jena University Hospital, 07740, Jena, Germany
| | | | | | - Bashdar Mahmud Hussen
- Department of Pharmacognosy, College of Pharmacy, Hawler Medical University, Kurdistan Region, Erbil, Iraq.,Center of Research and Strategic Studies, Lebanese French University, Erbil, Kurdistan Region, Iraq
| | - Aria Baniahmad
- Institute of Human Genetics, Jena University Hospital, 07740, Jena, Germany.
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Silverman LI, Dulatova G, Tandeski T, Erickson IE, Lundell B, Toplon D, Wolff T, Howard A, Chintalacharuvu S, Foley KT. In vitro and in vivo evaluation of discogenic cells, an investigational cell therapy for disc degeneration. Spine J 2020; 20:138-149. [PMID: 31442616 DOI: 10.1016/j.spinee.2019.08.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Revised: 08/13/2019] [Accepted: 08/14/2019] [Indexed: 02/03/2023]
Abstract
BACKGROUND/CONTEXT Disc degeneration (DD) is a significant driver of low back pain and few treatments exist to treat the pain and disability associated with the disease. PURPOSE Our group has developed a method to generate therapeutic discogenic cells as a potential treatment for symptomatic DD. These cells are derived and modified from adult nucleus pulposus cells. In this study, we evaluated the characteristics, mode of action, and in vivo efficacy and safety of these cells prior to human clinical testing. STUDY DESIGN Privately funded in vitro studies and in vivo preclinical models were used in this study. METHODS Discogenic cells generated from different adult human donors were evaluated for surface marker expression profile, matrix deposition and tumorigenic potential. Discogenic cells were then injected subcutaneously into nude mice to assess cell survival and possible extracellular matrix production in vivo. Finally, a rabbit model of DD was used to evaluate the therapeutic potential of discogenic cells after disc injury. RESULTS We found that discogenic cells have a consistent surface marker profile, are multipotent for mesenchymal lineages, and produce extracellular matrix consisting of aggrecan, collagen 1 and collagen 2. Cells did not show abnormal karyotype after culturing and did not form tumor-like aggregates in soft agar. After subcutaneous implantation in a nude mouse model, the human discogenic cells were found to have generated regions rich with extracellular matrix over the course of 4 months, with no signs of tumorigenicity. Intradiscal injection of human discogenic cells in a rabbit model of DD caused an increase in disc height and improvement of tissue architecture relative to control discs or injection of vehicle alone (no cells) with no signs of toxicity. CONCLUSIONS This study demonstrates that intradiscal injection of discogenic cells may be a viable treatment for human degenerative disc disease. The cells produce extracellular matrix that may rebuild the depleting tissue within degenerating discs. Also, the cells do not pose any significant safety concerns. CLINICAL SIGNIFICANCE Human clinical testing of discogenic cells combined with a sodium hyaluronate carrier is ongoing in multiple randomized, controlled, double-blinded studies in the United States (clinicaltrials.gov identifier NCT03347708) and Japan (clinicaltrials.gov identifier NCT03955315).
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Affiliation(s)
- Lara Ionescu Silverman
- DiscGenics, Inc, 5940 W Harold Gatty Dr, Salt Lake City, UT 84116, USA; Department of Neurosurgery, University of Tennessee Health Science Center, Memphis, TN, USA.
| | - Galina Dulatova
- DiscGenics, Inc, 5940 W Harold Gatty Dr, Salt Lake City, UT 84116, USA
| | - Terry Tandeski
- DiscGenics, Inc, 5940 W Harold Gatty Dr, Salt Lake City, UT 84116, USA
| | - Isaac E Erickson
- DiscGenics, Inc, 5940 W Harold Gatty Dr, Salt Lake City, UT 84116, USA
| | | | - David Toplon
- WuXi AppTec, 2540 Executive Drive, St. Paul, MN 55120, USA
| | - Tricia Wolff
- Covance Laboratories, 671 S. Meridian Rd, Greenfield, IN, USA
| | - Antwain Howard
- Covance Laboratories, 671 S. Meridian Rd, Greenfield, IN, USA
| | | | - Kevin T Foley
- DiscGenics, Inc, 5940 W Harold Gatty Dr, Salt Lake City, UT 84116, USA; Department of Neurosurgery, University of Tennessee Health Science Center, Memphis, TN, USA; Semmes-Murphey Clinic, 6325 Humphreys Blvd, Memphis, TN, USA
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3
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Jaiswal RK, Yadava PK. TGF-β-mediated regulation of plasminogen activators is human telomerase reverse transcriptase dependent in cancer cells. Biofactors 2019; 45:803-817. [PMID: 31317567 DOI: 10.1002/biof.1543] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Accepted: 06/19/2019] [Indexed: 02/06/2023]
Abstract
Telomerase is a specialized reverse transcriptase/terminal transferase enzyme that adds telomeric repeat sequences at the extreme end of a newly replicated chromosome. Apart from telomere lengthening, telomerase has many extracurricular activities. Telomerase is known to regulate the expression of many genes and helps in cancer progression and epithelial-to-mesenchymal transitions (EMTs). We have previously reported that human telomerase reverse transcriptase (hTERT) regulates the expression of plasminogen activator such as urokinase-type plasminogen activator (uPA) in cancer cells following a genome-wide transcriptomic study. Here, we present data substantiating these results in terms of real-time assays, western blots, and immunofluorescence. Another aim of this study is to find out the possible mechanism by which hTERT regulates the expression of plasminogen activators. We have used some molecular biology techniques such as quantitative real-time polymerase chain reaction, western blotting, and immunofluorescence and some assays such as wound healing assay and colony formation assay to solve this question. In this study, we show a positive association between hTERT and uPA. We also demonstrate that hTERT enhances uPA expression concomitant with EMT. Knocking down of hTERT reduces uPA expression as well as reverses EMT in cancer cells. We have also found that uPA is a transforming growth factor beta (TGF-β)-induced protein. Our observations establish that TGF-β-induced uPA expression is hTERT dependent.
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Affiliation(s)
- Rishi K Jaiswal
- Applied Molecular Biology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, Delhi, India
| | - Pramod K Yadava
- Applied Molecular Biology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, Delhi, India
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Affiliation(s)
- Deepak Kumar Mishra
- Applied Molecular Biology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi 110 067, India
| | - Pramod K Yadava
- Department of Biological Sciences, Indian Institute of Science Education and Research, Berhampur 760 010, Odisha, India
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Yadav SS, Kumar M, Varshney A, Yadava PK. KLF4 sensitizes the colon cancer cell HCT-15 to cisplatin by altering the expression of HMGB1 and hTERT. Life Sci 2019; 220:169-176. [PMID: 30716337 DOI: 10.1016/j.lfs.2019.02.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2018] [Revised: 01/19/2019] [Accepted: 02/01/2019] [Indexed: 12/17/2022]
Abstract
AIMS Insensitivity of cancer cells to therapeutic drugs is the most daunting challenge in cancer treatment. The mechanism of developing chemo-resistance is only partly understood to date. In continuation of some earlier reports, we hypothesize that KLF4, a key transcription factors that also has a crucial role in maintaining the stemness in cancer cells, may offer a basis for chemo-resistance. MAIN METHODS Sensitivity of cells to cisplatin was analyzed by cell proliferation, colony formation, and cell growth assay. Cell cycle analysis and immunophenotyping were used to measure cell cycle arrest and level of reactive oxygen species respectively. Immunoblotting was used to analyze the change in expression hTERT and HMGB1 involved in KLF4 mediated cisplatin resistance. KEY FINDINGS We found that KLF4 expression sensitizes cancer cell to cisplatin cytotoxicity. Further, KLF4 promotes the cisplatin-mediated G2/M cell cycle arrest while KLF4 knocked down induces cisplatin-mediated S-phase arrest compared to control. Decreased level of reactive oxygen species (ROS) in cisplatin-treated and KLF4 knocked down HCT-15 cells compared to vector control, accounting for increased cell survival. Immuno-blotting showed that KLF4 positively regulates expression of the survival proteins hTERT and HMGB1 while in presence of cisplatin, expression of HMGB1 and hTERT is negatively regulated by KLF4. SIGNIFICANCE This study suggests the involvement of KLF4-HMGB1/hTERT signaling in offering the basis for chemo-resistance in colon cancer cells and KLF4 overexpression as a probable strategy for sensitizing drug-resistant cancer cells to chemotherapy. The present study opens up new avenues for cancer research and therapeutics.
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Affiliation(s)
| | - Manoj Kumar
- Applied Molecular Biology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi 110067, India
| | - Akhil Varshney
- Centre for Advanced Vision Science, University of Virginia, 415 Lane Road, Charlottesville, VA 22908, USA
| | - Pramod Kumar Yadava
- Applied Molecular Biology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi 110067, India.
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6
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Varshney A, Bala J, Santosh B, Bhaskar A, Kumar S, Yadava PK. Identification of an RNA aptamer binding hTERT-derived peptide and inhibiting telomerase activity in MCF7 cells. Mol Cell Biochem 2016; 427:157-167. [PMID: 28004350 DOI: 10.1007/s11010-016-2907-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Accepted: 12/03/2016] [Indexed: 01/30/2023]
Abstract
Human telomerase reverse transcriptase is an essential rate-limiting component of telomerase complex. hTERT protein in association with other proteins and the human telomerase RNA (hTR) shows telomerase activity, essential for maintaining genomic integrity in proliferating cells. hTERT binds hTR through a decapeptide located in the RID2 (RNA interactive domain 2) domain of N-terminal region. Since hTERT is essential for telomerase activity, inhibitors of hTERT are of great interest as potential anti-cancer agent. We have selected RNA aptamers against a synthetic peptide from the RID2 domain of hTERT by employing in vitro selection protocol (SELEX). The selected RNAs could bind the free peptide, as CD spectra suggested conformational change in aptamer upon RID2 binding. Extracts of cultured breast cancer cells (MCF7) expressing this aptamer showed lower telomerase activity as estimated by TRAP assay. hTERT-binding RNA aptamers hold promise as probable anti-cancer therapeutic agent.
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Affiliation(s)
- Akhil Varshney
- Applied Molecular Biology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Jyoti Bala
- Applied Molecular Biology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Baby Santosh
- Applied Molecular Biology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Ashima Bhaskar
- Applied Molecular Biology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Suresh Kumar
- Applied Molecular Biology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067, India.,Molecular Genetics Laboratory, Institute of Cytogenetic and Preventive Oncology, Indian Council of Medical Research, Noida, Uttar Pradesh, 201301, India
| | - Pramod K Yadava
- Applied Molecular Biology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067, India.
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Kang HJ, Cui Y, Yin H, Scheid A, Hendricks WPD, Schmidt J, Sekulic A, Kong D, Trent JM, Gokhale V, Mao H, Hurley LH. A Pharmacological Chaperone Molecule Induces Cancer Cell Death by Restoring Tertiary DNA Structures in Mutant hTERT Promoters. J Am Chem Soc 2016; 138:13673-13692. [PMID: 27643954 DOI: 10.1021/jacs.6b07598] [Citation(s) in RCA: 76] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Activation of human telomerase reverse transcriptase (hTERT) is necessary for limitless replication in tumorigenesis. Whereas hTERT is transcriptionally silenced in normal cells, most tumor cells reactivate hTERT expression by alleviating transcriptional repression through diverse genetic and epigenetic mechanisms. Transcription-activating hTERT promoter mutations have been found to occur at high frequencies in multiple cancer types. These mutations have been shown to form new transcription factor binding sites that drive hTERT expression, but this model cannot fully account for differences in wild-type (WT) and mutant promoter activation and has not yet enabled a selective therapeutic strategy. Here, we demonstrate a novel mechanism by which promoter mutations activate hTERT transcription, which also sheds light on a unique therapeutic opportunity. Promoter mutations occur in a core promoter region that forms tertiary structures consisting of a pair of G-quadruplexes involved in transcriptional silencing. We show that promoter mutations exert a detrimental effect on the folding of one of these G-quadruplexes, resulting in a nonfunctional silencer element that alleviates transcriptional repression. We have also identified a small drug-like pharmacological chaperone (pharmacoperone) molecule, GTC365, that acts at an early step in the G-quadruplex folding pathway to redirect mutant promoter G-quadruplex misfolding, partially reinstate the correct folding pathway, and reduce hTERT activity through transcriptional repression. This transcription-mediated repression produces cancer cell death through multiple routes including both induction of apoptosis through inhibition of hTERT's role in regulating apoptosis-related proteins and induction of senescence by decreasing telomerase activity and telomere length. We demonstrate the selective therapeutic potential of this strategy in melanoma cells that overexpress hTERT.
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Affiliation(s)
- Hyun-Jin Kang
- University of Arizona , College of Pharmacy, 1703 East Mabel Street, Tucson, Arizona 85721, United States
| | - Yunxi Cui
- Department of Chemistry and Biochemistry and School of Biomedical Sciences, Kent State University , Kent, Ohio 44242, United States
| | - Holly Yin
- Translational Genomics Research Institute , 445 North Fifth Street, Phoenix, Arizona 85004, United States
| | - Amy Scheid
- College of Science, University of Arizona , 1040 East Fourth Street, Tucson, Arizona 85721, United States
| | - William P D Hendricks
- Translational Genomics Research Institute , 445 North Fifth Street, Phoenix, Arizona 85004, United States
| | - Jessica Schmidt
- Department of Dermatology, Mayo Clinic , 13400 East Shea Boulevard, Scottsdale, Arizona 85259, United States
| | - Aleksandar Sekulic
- Department of Dermatology, Mayo Clinic , 13400 East Shea Boulevard, Scottsdale, Arizona 85259, United States
| | - Deming Kong
- State Key Laboratory of Medicinal Chemical Biology, College of Chemistry, Nankai University , Tianjin 300071, People's Republic of China
| | - Jeffrey M Trent
- Translational Genomics Research Institute , 445 North Fifth Street, Phoenix, Arizona 85004, United States
| | - Vijay Gokhale
- BIO5 Institute , 1657 East Helen Street, Tucson, Arizona 85721, United States
| | - Hanbin Mao
- Department of Chemistry and Biochemistry and School of Biomedical Sciences, Kent State University , Kent, Ohio 44242, United States
| | - Laurence H Hurley
- University of Arizona , College of Pharmacy, 1703 East Mabel Street, Tucson, Arizona 85721, United States.,BIO5 Institute , 1657 East Helen Street, Tucson, Arizona 85721, United States.,Arizona Cancer Center , 1515 North Campbell Avenue, Tucson, Arizona 85724, United States
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8
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Ait-Aissa K, Ebben JD, Kadlec AO, Beyer AM. Friend or foe? Telomerase as a pharmacological target in cancer and cardiovascular disease. Pharmacol Res 2016; 111:422-433. [PMID: 27394166 PMCID: PMC5026584 DOI: 10.1016/j.phrs.2016.07.003] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Revised: 07/01/2016] [Accepted: 07/02/2016] [Indexed: 12/20/2022]
Abstract
Aging, cancer, and chronic disease have remained at the forefront of basic biological research for decades. Within this context, significant attention has been paid to the role of telomerase, the enzyme responsible for lengthening telomeres, the nucleotide sequences located at the end of chromosomes found in the nucleus. Alterations in telomere length and telomerase activity are a common denominator to the underlying pathology of these diseases. While nuclear-specific, telomere-lengthening effects of telomerase impact cellular/organismal aging and cancer development, non-canonical, extra-nuclear, and non-telomere-lengthening contributions of telomerase have only recently been described and their exact physiological implications are ill defined. Although the mechanism remains unclear, recent reports reveal that the catalytic subunit of telomerase, telomerase reverse transcriptase (TERT), regulates levels of mitochondrial-derived reactive oxygen species (mtROS), independent of its established role in the nucleus. Telomerase inhibition has been the target of chemotherapy (directed or indirectly) for over a decade now, yet no telomerase inhibitor is FDA approved and few are currently in late-stage clinical trials, possibly due to underappreciation of the distinct extra-nuclear functions of telomerase. Moreover, evaluation of telomerase-specific therapies is largely limited to the context of chemotherapy, despite reports of the beneficial effects of telomerase activation in the cardiovascular system in relation to such processes as endothelial dysfunction and myocardial infarction. Thus, there is a need for better understanding of telomerase-focused cell and organism physiology, as well as development of telomerase-specific therapies in relation to cancer and extension of these therapies to cardiovascular pathologies. This review will detail findings related to telomerase and evaluate its potential to serve as a therapeutic target.
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Affiliation(s)
- Karima Ait-Aissa
- Department of Medicine
- Department of Physiology, Cardiovascular Center
| | - Johnathan D. Ebben
- Department of Pharmacology & Toxicology
- Cancer Center, Medical College of Wisconsin
| | - Andrew O. Kadlec
- Department of Medicine
- Department of Physiology, Cardiovascular Center
| | - Andreas M. Beyer
- Department of Medicine
- Department of Physiology, Cardiovascular Center
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Transcription Regulation of the Human Telomerase Reverse Transcriptase (hTERT) Gene. Genes (Basel) 2016; 7:genes7080050. [PMID: 27548225 PMCID: PMC4999838 DOI: 10.3390/genes7080050] [Citation(s) in RCA: 101] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Revised: 07/23/2016] [Accepted: 08/01/2016] [Indexed: 12/11/2022] Open
Abstract
Embryonic stem cells and induced pluripotent stem cells have the ability to maintain their telomere length via expression of an enzymatic complex called telomerase. Similarly, more than 85%–90% of cancer cells are found to upregulate the expression of telomerase, conferring them with the potential to proliferate indefinitely. Telomerase Reverse Transcriptase (TERT), the catalytic subunit of telomerase holoenzyme, is the rate-limiting factor in reconstituting telomerase activity in vivo. To date, the expression and function of the human Telomerase Reverse Transcriptase (hTERT) gene are known to be regulated at various molecular levels (including genetic, mRNA, protein and subcellular localization) by a number of diverse factors. Among these means of regulation, transcription modulation is the most important, as evident in its tight regulation in cancer cell survival as well as pluripotent stem cell maintenance and differentiation. Here, we discuss how hTERT gene transcription is regulated, mainly focusing on the contribution of trans-acting factors such as transcription factors and epigenetic modifiers, as well as genetic alterations in hTERT proximal promoter.
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