1
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Fan W, Li X. The SIRT1-c-Myc axis in regulation of stem cells. Front Cell Dev Biol 2023; 11:1236968. [PMID: 37554307 PMCID: PMC10405831 DOI: 10.3389/fcell.2023.1236968] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Accepted: 07/10/2023] [Indexed: 08/10/2023] Open
Abstract
SIRT1 is the most conserved mammalian NAD+-dependent protein deacetylase. Through deacetylation of transcriptional factors and co-factors, this protein modification enzyme is critically involved in metabolic and epigenetic regulation of stem cells, which is functionally important in maintaining their pluripotency and regulating their differentiation. C-Myc, a key member of Myc proton-oncogene family, is a pivotal factor for transcriptional regulation of genes that control acquisition and maintenance of stemness. Previous cancer research has revealed an intriguing positive feedback loop between SIRT1 and c-Myc that is crucial in tumorigenesis. Recent literature has uncovered important functions of this axis in regulation of maintenance and differentiation of stem cells, including pluripotent stem cells and cancer stem cells. This review highlights recent advances of the SIRT1-c-Myc axis in stem cells.
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Affiliation(s)
- Wei Fan
- Signal Transduction Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, Durham, NC, United States
| | - Xiaoling Li
- Signal Transduction Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, Durham, NC, United States
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2
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Chen M, Chen X, Huang G, Jiang Y, Gou Y, Deng J. Synthesis, anti-tumour activity, and mechanism of benzoyl hydrazine Schiff base-copper complexes. J Mol Struct 2022. [DOI: 10.1016/j.molstruc.2022.133730] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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3
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Engin AB, Engin A. The Connection Between Cell Fate and Telomere. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1275:71-100. [PMID: 33539012 DOI: 10.1007/978-3-030-49844-3_3] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Abolition of telomerase activity results in telomere shortening, a process that eventually destabilizes the ends of chromosomes, leading to genomic instability and cell growth arrest or death. Telomere shortening leads to the attainment of the "Hayflick limit", and the transition of cells to state of senescence. If senescence is bypassed, cells undergo crisis through loss of checkpoints. This process causes massive cell death concomitant with further telomere shortening and spontaneous telomere fusions. In functional telomere of mammalian cells, DNA contains double-stranded tandem repeats of TTAGGG. The Shelterin complex, which is composed of six different proteins, is required for the regulation of telomere length and stability in cells. Telomere protection by telomeric repeat binding protein 2 (TRF2) is dependent on DNA damage response (DDR) inhibition via formation of T-loop structures. Many protein kinases contribute to the DDR activated cell cycle checkpoint pathways, and prevent DNA replication until damaged DNA is repaired. Thereby, the connection between cell fate and telomere length-associated telomerase activity is regulated by multiple protein kinase activities. Contrarily, inactivation of DNA damage checkpoint protein kinases in senescent cells can restore cell-cycle progression into S phase. Therefore, telomere-initiated senescence is a DNA damage checkpoint response that is activated with a direct contribution from dysfunctional telomeres. In this review, in addition to the above mentioned, the choice of main repair pathways, which comprise non-homologous end joining and homologous recombination in telomere uncapping telomere dysfunctions, are discussed.
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Affiliation(s)
- Ayse Basak Engin
- Department of Toxicology, Faculty of Pharmacy, Gazi University, Ankara, Turkey.
| | - Atilla Engin
- Department of General Surgery, Faculty of Medicine, Gazi University, Ankara, Turkey
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4
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Rattan SIS. Biogerontology: research status, challenges and opportunities. ACTA BIO-MEDICA : ATENEI PARMENSIS 2018; 89:291-301. [PMID: 29957767 PMCID: PMC6179011 DOI: 10.23750/abm.v89i2.7403] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Accepted: 03/29/2018] [Indexed: 01/09/2023]
Abstract
Biogerontology is the study of the biological basis of ageing and age-related diseases. The phenomenon and the process of ageing are well understood in evolutionary and biological terms; and a conceptual framework has been established within which general principles of ageing and longevity can be formulated. The phenotype of ageing in terms of progressive loss of physical function and fitness is best seen during the period of survival after the evolution-determined essential lifespan (ELS) of a species. However, the ageing phenotype is highly heterogenous and individualistic at all levels from the whole body to the molecular one. Most significantly, the process and the progression of ageing are not determined by any specific gerontogenes. Ageing is the result of imperfect maintenance and repair systems that allow a progressive shrinkage of the homeodynamic space of an individual. The challenge is to develop and apply wholistic approaches to the complex trait of ageing for maintaining and/or improving health. One such approach is that of mild stress-induced physiological hormesis by physical, mental and nutritional hormetins. Biogerontological research offers numerous opportunities for developing evidence-based novel biomedical technologies for maintaining and improving health, for preventing the onset of age-related diseases, and for extending the health-span.
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Affiliation(s)
- Suresh I S Rattan
- Laboratory of Cellular Ageing, Department of Molecular Biology and Genetics, Aarhus University, Denmark.
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5
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Abstract
PURPOSE OF REVIEW The activation of telomere maintenance pathways has long been regarded as a key hallmark of cancer and this has propelled the development of novel inhibitors of telomerase. In this review, we detail the background biology on telomere maintenance in health and disease, then concentrate on the recent preclinical and clinical development behind targeting telomerase in blood cancers. RECENT FINDINGS Preclinical and clinical studies have shown that imetelstat, a competitive inhibitor of telomerase, has activity in certain hematologic malignancies, in particular the myeloproliferative neoplasms and acute myeloid leukemia. SUMMARY Telomerase inhibition has shown remarkable efficacy in myeloid malignancies, and current and future preclinical and clinical studies are necessary to comprehensively investigate its underlying mechanism of action. Future work should identify the potential genetic susceptibilities to telomerase inhibition therapy, and evaluate rational combinations of telomerase inhibitors with chemotherapy and other novel agents. Robust preclinical evaluation is essential to best translate these new agents successfully into our clinical treatment algorithm for myeloid and other blood cancers.
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6
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Qin QP, Qin JL, Chen M, Li YL, Meng T, Zhou J, Liang H, Chen ZF. Chiral platinum (II)-4-(2,3-dihydroxypropyl)- formamide oxo-aporphine (FOA) complexes promote tumor cells apoptosis by directly targeting G-quadruplex DNA in vitro and in vivo. Oncotarget 2017; 8:61982-61997. [PMID: 28977920 PMCID: PMC5617480 DOI: 10.18632/oncotarget.18778] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Accepted: 05/06/2017] [Indexed: 11/25/2022] Open
Abstract
Three platinum(II) complexes, 4 (LC-004), 5 (LC-005), and 6 (LC-006), with the chiral FOA ligands R/S-(±)-FOA (1), R-(+)-FOA (2) and S-(–)-FOA (3), respectively, were synthesized and characterized. As potential anti-tumor agents, these complexes show higher cytotoxicity to BEL-7404 cells than the HL-7702 normal cells. They are potential telomerase inhibitors that target c-myc and human telomeric G-quadruplex DNA. Compared to complexes 4 and 5, 6 exhibited higher binding affinities towards telomeric, c-myc G-quadruplex DNA and caspase-3/9, thereby inducing senescence and apoptosis to a greater extent in tumor cells. Moreover, our in vivo studies showed that complex 6 can effectively inhibit tumor growth in the BEL-7404 and BEL-7402 xenograft mouse models and is less toxic than 5-fluorouracil and cisplatin. The effective inhibition of tumor growth is attributed to its interactions with 53BP1, TRF1, c-myc, TRF2, and hTERT. Thus, complex 6 can serve as a novel lead compound and a potential drug candidate for anticancer chemotherapy.
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Affiliation(s)
- Qi-Pin Qin
- State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources, School of Chemistry and Pharmacy, Guangxi Normal University, Guilin 541004, P. R. China
| | - Jiao-Lan Qin
- State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources, School of Chemistry and Pharmacy, Guangxi Normal University, Guilin 541004, P. R. China
| | - Ming Chen
- State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources, School of Chemistry and Pharmacy, Guangxi Normal University, Guilin 541004, P. R. China
| | - Yu-Lan Li
- State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources, School of Chemistry and Pharmacy, Guangxi Normal University, Guilin 541004, P. R. China
| | - Ting Meng
- State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources, School of Chemistry and Pharmacy, Guangxi Normal University, Guilin 541004, P. R. China
| | - Jie Zhou
- State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources, School of Chemistry and Pharmacy, Guangxi Normal University, Guilin 541004, P. R. China
| | - Hong Liang
- State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources, School of Chemistry and Pharmacy, Guangxi Normal University, Guilin 541004, P. R. China
| | - Zhen-Feng Chen
- State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources, School of Chemistry and Pharmacy, Guangxi Normal University, Guilin 541004, P. R. China
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7
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Zou BQ, Qin QP, Bai YX, Cao QQ, Zhang Y, Liu YC, Chen ZF, Liang H. Synthesis and antitumor mechanism of a new iron(iii) complex with 5,7-dichloro-2-methyl-8-quinolinol as ligands. MEDCHEMCOMM 2017; 8:633-639. [PMID: 30108780 PMCID: PMC6072324 DOI: 10.1039/c6md00644b] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2016] [Accepted: 01/26/2017] [Indexed: 11/21/2022]
Abstract
A new iron(iii) complex with 5,7-dichloro-2-methyl-8-quinolinol (HClMQ) as ligands, i.e., [Fe(ClMQ)2Cl] (1), was synthesized and evaluated for its anticancer activity. Compared to the HClMQ ligand, complex 1 showed a higher cytotoxicity towards a series of tumor cell lines, including Hep-G2, BEL-7404, NCI-H460, A549, and T-24, with IC50 values in the range of 5.04-14.35 μM. Notably, the Hep-G2 cell line was the most sensitive to complex 1. Mechanistic studies indicated that complex 1 is a telomerase inhibitor targeting c-myc G-quadruplex DNA and can trigger cell apoptosis via inducing cell cycle arrest and DNA damage.
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Affiliation(s)
- Bi-Qun Zou
- State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources , School of Chemistry & Pharmaceutical Sciences , Guangxi Normal University , Guilin , Guangxi 541004 , P. R. China . ; ; ; ; Tel: +86 773 2120958
- Department of Chemistry , Guilin Normal College , Guilin , Guangxi 541001 , P. R. China
| | - Qi-Pin Qin
- State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources , School of Chemistry & Pharmaceutical Sciences , Guangxi Normal University , Guilin , Guangxi 541004 , P. R. China . ; ; ; ; Tel: +86 773 2120958
| | - Yu-Xia Bai
- State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources , School of Chemistry & Pharmaceutical Sciences , Guangxi Normal University , Guilin , Guangxi 541004 , P. R. China . ; ; ; ; Tel: +86 773 2120958
| | - Qian-Qian Cao
- State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources , School of Chemistry & Pharmaceutical Sciences , Guangxi Normal University , Guilin , Guangxi 541004 , P. R. China . ; ; ; ; Tel: +86 773 2120958
| | - Ye Zhang
- State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources , School of Chemistry & Pharmaceutical Sciences , Guangxi Normal University , Guilin , Guangxi 541004 , P. R. China . ; ; ; ; Tel: +86 773 2120958
- Department of Chemistry , Guilin Normal College , Guilin , Guangxi 541001 , P. R. China
- College of Pharmacy , Guilin Medical University , North Ring 2rd Road 109 , Guilin 541004 , P. R. China
| | - Yan-Cheng Liu
- State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources , School of Chemistry & Pharmaceutical Sciences , Guangxi Normal University , Guilin , Guangxi 541004 , P. R. China . ; ; ; ; Tel: +86 773 2120958
| | - Zhen-Feng Chen
- State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources , School of Chemistry & Pharmaceutical Sciences , Guangxi Normal University , Guilin , Guangxi 541004 , P. R. China . ; ; ; ; Tel: +86 773 2120958
| | - Hong Liang
- State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources , School of Chemistry & Pharmaceutical Sciences , Guangxi Normal University , Guilin , Guangxi 541004 , P. R. China . ; ; ; ; Tel: +86 773 2120958
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8
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Qin QP, Qin JL, Meng T, Yang GA, Wei ZZ, Liu YC, Liang H, Chen ZF. Preparation of 6/8/11-Amino/Chloro-Oxoisoaporphine and Group-10 Metal Complexes and Evaluation of Their in Vitro and in Vivo Antitumor Activity. Sci Rep 2016; 6:37644. [PMID: 27898051 PMCID: PMC5127189 DOI: 10.1038/srep37644] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Accepted: 09/19/2016] [Indexed: 12/26/2022] Open
Abstract
A series of group-10 metal complexes 1–14 of oxoisoaporphine derivatives were designed and synthesized. 1–14 were more selectively cytotoxic to Hep-G2 cells comparing with normal liver cells. In vitro cytotoxicity results showed that complexes 1–6, 7, 8, 10 and 11, especially 3, were telomerase inhibitors targeting c-myc, telomeric, and bcl-2 G4s and triggered cell senescence and apoptosis; they also caused telomere/DNA damage and S phase arrest. In addition, 1–6 also caused mitochondrial dysfunction. Notably, 3 with 6-amino substituted ligand La exhibited less side effects than 6 with 8-amino substituted ligand Lb and cisplatin, but similar tumor growth inhibition efficacy in BEL-7402 xenograft model. Complex 3 has the potential to be developed as an effective anticancer agent.
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Affiliation(s)
- Qi-Pin Qin
- State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources, School of Chemistry and Pharmacy, Guangxi Normal University, 15 Yucai Road, Guilin 541004, P.R. China
| | - Jiao-Lan Qin
- State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources, School of Chemistry and Pharmacy, Guangxi Normal University, 15 Yucai Road, Guilin 541004, P.R. China
| | - Ting Meng
- State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources, School of Chemistry and Pharmacy, Guangxi Normal University, 15 Yucai Road, Guilin 541004, P.R. China
| | - Gui-Ai Yang
- State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources, School of Chemistry and Pharmacy, Guangxi Normal University, 15 Yucai Road, Guilin 541004, P.R. China
| | - Zu-Zhuang Wei
- State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources, School of Chemistry and Pharmacy, Guangxi Normal University, 15 Yucai Road, Guilin 541004, P.R. China
| | - Yan-Cheng Liu
- State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources, School of Chemistry and Pharmacy, Guangxi Normal University, 15 Yucai Road, Guilin 541004, P.R. China
| | - Hong Liang
- State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources, School of Chemistry and Pharmacy, Guangxi Normal University, 15 Yucai Road, Guilin 541004, P.R. China
| | - Zhen-Feng Chen
- State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources, School of Chemistry and Pharmacy, Guangxi Normal University, 15 Yucai Road, Guilin 541004, P.R. China
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9
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Chen Y, Zhang Y. Functional and mechanistic analysis of telomerase: An antitumor drug target. Pharmacol Ther 2016; 163:24-47. [DOI: 10.1016/j.pharmthera.2016.03.017] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Accepted: 03/29/2016] [Indexed: 01/26/2023]
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10
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Mechanism studies on anti-HepG2 cell proliferation of phenanthroline derivatives as G-quadruplex DNA stabilizers. Bioorg Med Chem Lett 2015; 25:3798-803. [DOI: 10.1016/j.bmcl.2015.07.085] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Revised: 07/06/2015] [Accepted: 07/25/2015] [Indexed: 12/13/2022]
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11
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Chen ZF, Qin QP, Qin JL, Zhou J, Li YL, Li N, Liu YC, Liang H. Water-Soluble Ruthenium(II) Complexes with Chiral 4-(2,3-Dihydroxypropyl)-formamide Oxoaporphine (FOA): In Vitro and in Vivo Anticancer Activity by Stabilization of G-Quadruplex DNA, Inhibition of Telomerase Activity, and Induction of Tumor Cell Apoptosis. J Med Chem 2015; 58:4771-89. [PMID: 25988535 DOI: 10.1021/acs.jmedchem.5b00444] [Citation(s) in RCA: 100] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Three water-soluble ruthenium(II) complexes with chiral 4-(2,3-dihydroxypropyl)-formamide oxoaporphine (FOA) were synthesized and characterized. It was found that these ruthenium(II) complexes exhibited considerable in vitro anticancer activities and that they were the effective stabilizers of telomeric and G-quadruplex-DNA (G4-DNA) in promoter of c-myc, which acted as a telomerase inhibitor targeting G4-DNA and induced cell senescence and apoptosis. Interestingly, the in vitro anticancer activity of 6 (LC-003) was higher than those of 4 (LC-001) and 5 (LC-002), more selective for BEL-7404 cells than for normal HL-7702 cells, and preferred to activate caspases-3/9. The different biological behaviors of the ruthenium complexes could be correlated with the chiral nature of 4-(2,3-dihydroxypropyl)-formamide oxoaporphine. More significantly, 6 exhibited effective inhibitory on tumor growth in BEL-7402 xenograft mouse model and higher in vivo safety than cisplatin. These mechanistic insights indicate that 6 displays low toxicity and can be a novel anticancer drug candidate.
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Affiliation(s)
- Zhen-Feng Chen
- State Key Laboratory Cultivation Base for the Chemistry and Molecular Engineering of Medicinal Resources, School of Chemistry and Pharmacy, Guangxi Normal University, 15 Yucai Road, Guilin 541004, P. R. China
| | - Qi-Pin Qin
- State Key Laboratory Cultivation Base for the Chemistry and Molecular Engineering of Medicinal Resources, School of Chemistry and Pharmacy, Guangxi Normal University, 15 Yucai Road, Guilin 541004, P. R. China
| | - Jiao-Lan Qin
- State Key Laboratory Cultivation Base for the Chemistry and Molecular Engineering of Medicinal Resources, School of Chemistry and Pharmacy, Guangxi Normal University, 15 Yucai Road, Guilin 541004, P. R. China
| | - Jie Zhou
- State Key Laboratory Cultivation Base for the Chemistry and Molecular Engineering of Medicinal Resources, School of Chemistry and Pharmacy, Guangxi Normal University, 15 Yucai Road, Guilin 541004, P. R. China
| | - Yu-Lan Li
- State Key Laboratory Cultivation Base for the Chemistry and Molecular Engineering of Medicinal Resources, School of Chemistry and Pharmacy, Guangxi Normal University, 15 Yucai Road, Guilin 541004, P. R. China
| | - Nan Li
- State Key Laboratory Cultivation Base for the Chemistry and Molecular Engineering of Medicinal Resources, School of Chemistry and Pharmacy, Guangxi Normal University, 15 Yucai Road, Guilin 541004, P. R. China
| | - Yan-Cheng Liu
- State Key Laboratory Cultivation Base for the Chemistry and Molecular Engineering of Medicinal Resources, School of Chemistry and Pharmacy, Guangxi Normal University, 15 Yucai Road, Guilin 541004, P. R. China
| | - Hong Liang
- State Key Laboratory Cultivation Base for the Chemistry and Molecular Engineering of Medicinal Resources, School of Chemistry and Pharmacy, Guangxi Normal University, 15 Yucai Road, Guilin 541004, P. R. China
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12
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Koh CM, Khattar E, Leow SC, Liu CY, Muller J, Ang WX, Li Y, Franzoso G, Li S, Guccione E, Tergaonkar V. Telomerase regulates MYC-driven oncogenesis independent of its reverse transcriptase activity. J Clin Invest 2015; 125:2109-22. [PMID: 25893605 PMCID: PMC4463203 DOI: 10.1172/jci79134] [Citation(s) in RCA: 122] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Accepted: 03/12/2015] [Indexed: 12/25/2022] Open
Abstract
Constitutively active MYC and reactivated telomerase often coexist in cancers. While reactivation of telomerase is thought to be essential for replicative immortality, MYC, in conjunction with cofactors, confers several growth advantages to cancer cells. It is known that the reactivation of TERT, the catalytic subunit of telomerase, is limiting for reconstituting telomerase activity in tumors. However, while reactivation of TERT has been functionally linked to the acquisition of several "hallmarks of cancer" in tumors, the molecular mechanisms by which this occurs and whether these mechanisms are distinct from the role of telomerase on telomeres is not clear. Here, we demonstrated that first-generation TERT-null mice, unlike Terc-null mice, show delayed onset of MYC-induced lymphomagenesis. We further determined that TERT is a regulator of MYC stability in cancer. TERT stabilized MYC levels on chromatin, contributing to either activation or repression of its target genes. TERT regulated MYC ubiquitination and proteasomal degradation, and this effect of TERT was independent of its reverse transcriptase activity and role in telomere elongation. Based on these data, we conclude that reactivation of TERT, a direct transcriptional MYC target in tumors, provides a feed-forward mechanism to potentiate MYC-dependent oncogenesis.
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MESH Headings
- Animals
- Cell Line, Tumor
- Cell Transformation, Neoplastic/genetics
- Enzyme Activation
- Feedback, Physiological
- Gene Expression Regulation, Neoplastic/genetics
- Genes, myc
- Glycogen Synthase Kinase 3/physiology
- Glycogen Synthase Kinase 3 beta
- Heterografts
- Humans
- Lymphoma, Non-Hodgkin/pathology
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Neoplasm Proteins/genetics
- Neoplasm Proteins/metabolism
- Neoplasm Proteins/physiology
- Neoplasm Transplantation
- Phosphorylation
- Promoter Regions, Genetic
- Protein Processing, Post-Translational
- Protein Stability
- Proto-Oncogene Proteins c-myc/genetics
- Proto-Oncogene Proteins c-myc/metabolism
- Proto-Oncogene Proteins c-myc/physiology
- RNA/genetics
- RNA/physiology
- RNA Interference
- Telomerase/deficiency
- Telomerase/genetics
- Telomerase/physiology
- Telomere Homeostasis/genetics
- Time Factors
- Transcription, Genetic
- Ubiquitination
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Affiliation(s)
- Cheryl M. Koh
- Division of Cancer Genetics and Therapeutics, Laboratory of Methyltransferases in Development and Disease, and
| | - Ekta Khattar
- Division of Cancer Genetics and Therapeutics, Laboratory of NF-κB Signaling, Institute of Molecular and Cell Biology, Agency for Science, Technology and Research (A*STAR), Singapore
| | - Shi Chi Leow
- Division of Cancer Genetics and Therapeutics, Laboratory of NF-κB Signaling, Institute of Molecular and Cell Biology, Agency for Science, Technology and Research (A*STAR), Singapore
| | - Chia Yi Liu
- Division of Cancer Genetics and Therapeutics, Laboratory of NF-κB Signaling, Institute of Molecular and Cell Biology, Agency for Science, Technology and Research (A*STAR), Singapore
| | - Julius Muller
- Division of Cancer Genetics and Therapeutics, Laboratory of Methyltransferases in Development and Disease, and
| | - Wei Xia Ang
- Division of Cancer Genetics and Therapeutics, Laboratory of Methyltransferases in Development and Disease, and
| | - Yinghui Li
- Division of Cancer Genetics and Therapeutics, Laboratory of NF-κB Signaling, Institute of Molecular and Cell Biology, Agency for Science, Technology and Research (A*STAR), Singapore
| | - Guido Franzoso
- Department of Medicine, Imperial College London, London, United Kingdom
| | - Shang Li
- Program in Cancer and Stem Cell Biology, Duke-NUS Graduate Medical School, Singapore
- Department of Physiology and
| | - Ernesto Guccione
- Division of Cancer Genetics and Therapeutics, Laboratory of Methyltransferases in Development and Disease, and
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Vinay Tergaonkar
- Division of Cancer Genetics and Therapeutics, Laboratory of NF-κB Signaling, Institute of Molecular and Cell Biology, Agency for Science, Technology and Research (A*STAR), Singapore
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
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13
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Chen ZF, Qin QP, Qin JL, Liu YC, Huang KB, Li YL, Meng T, Zhang GH, Peng Y, Luo XJ, Liang H. Stabilization of G-quadruplex DNA, inhibition of telomerase activity, and tumor cell apoptosis by organoplatinum(II) complexes with oxoisoaporphine. J Med Chem 2015; 58:2159-79. [PMID: 25650792 DOI: 10.1021/jm5012484] [Citation(s) in RCA: 125] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Two G-quadruplex ligands [Pt(L(a))(DMSO)Cl] (Pt1) and [Pt(L(b))(DMSO)Cl] (Pt2) have been synthesized and fully characterized. The two complexes are more selective for SK-OV-3/DDP tumor cells versus normal cells (HL-7702). It was found that both Pt1 and Pt2 could be a telomerase inhibitor targeting G-quadruplex DNA. This is the first report demonstrating that telomeric, c-myc, and bcl-2 G-quadruplexes and caspase-3/9 preferred to bind with Pt2 rather than Pt1, which also can induce senescence and apoptosis. The different biological behavior of Pt1 and Pt2 may correlate with the presence of a 6-hydroxyl group in L(b). Importantly, Pt1 and Pt2 exhibited higher safety in vivo and more effective inhibitory effects on tumor growth in the HCT-8 and NCI-H460 xenograft mouse model, compared with cisplatin. Taken together, these mechanistic insights indicate that both Pt1 and Pt2 display low toxicity and could be novel anticancer drug candidates.
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Affiliation(s)
- Zhen-Feng Chen
- State Key Laboratory Cultivation Base for the Chemistry and Molecular Engineering of Medicinal Resources, School of Chemistry and Pharmacy, Guangxi Normal University , Yucai Road 15, Guilin 541004, P. R. China
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14
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Simonicova L, Dudekova H, Ferenc J, Prochazkova K, Nebohacova M, Dusinsky R, Nosek J, Tomaska L. Saccharomyces cerevisiae as a model for the study of extranuclear functions of mammalian telomerase. Curr Genet 2015; 61:517-27. [PMID: 25567623 DOI: 10.1007/s00294-014-0472-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2014] [Revised: 12/25/2014] [Accepted: 12/28/2014] [Indexed: 10/24/2022]
Abstract
The experimental evidence from the last decade made telomerase a prominent member of a family of moonlighting proteins performing different functions at various cellular loci. However, the study of extratelomeric functions of the catalytic subunit of mammalian telomerase (TERT) is often complicated by the fact that it is sometimes difficult to distinguish them from its role(s) at the chromosomal ends. Here, we present an experimental model for studying the extranuclear function(s) of mammalian telomerase in the yeast Saccharomyces cerevisiae. We demonstrate that the catalytic subunit of mammalian telomerase protects the yeast cells against oxidative stress and affects the stability of the mitochondrial genome. The advantage of using S. cerevisiae to study of mammalian telomerase is that (1) mammalian TERT does not interfere with its yeast counterpart in the maintenance of telomeres, (2) yeast telomerase is not localized in mitochondria and (3) it does not seem to be involved in the protection of cells against oxidative stress and stabilization of mtDNA. Thus, yeast cells can be used as a 'test tube' for reconstitution of mammalian TERT extranuclear function(s).
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Affiliation(s)
- Lucia Simonicova
- Department of Genetics, Faculty of Natural Sciences, Comenius University, Mlynska dolina, B-1, 84215, Bratislava, Slovak Republic
| | - Henrieta Dudekova
- Department of Genetics, Faculty of Natural Sciences, Comenius University, Mlynska dolina, B-1, 84215, Bratislava, Slovak Republic
| | - Jaroslav Ferenc
- Department of Genetics, Faculty of Natural Sciences, Comenius University, Mlynska dolina, B-1, 84215, Bratislava, Slovak Republic
| | - Katarina Prochazkova
- Department of Genetics, Faculty of Natural Sciences, Comenius University, Mlynska dolina, B-1, 84215, Bratislava, Slovak Republic
| | - Martina Nebohacova
- Department of Biochemistry, Faculty of Natural Sciences, Comenius University, Mlynska dolina, CH-1, 84215, Bratislava, Slovak Republic
| | - Roman Dusinsky
- Department of Genetics, Faculty of Natural Sciences, Comenius University, Mlynska dolina, B-1, 84215, Bratislava, Slovak Republic
| | - Jozef Nosek
- Department of Biochemistry, Faculty of Natural Sciences, Comenius University, Mlynska dolina, CH-1, 84215, Bratislava, Slovak Republic
| | - Lubomir Tomaska
- Department of Genetics, Faculty of Natural Sciences, Comenius University, Mlynska dolina, B-1, 84215, Bratislava, Slovak Republic.
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Qin QP, Chen ZF, Shen WY, Jiang YH, Cao D, Li YL, Xu QM, Liu YC, Huang KB, Liang H. Synthesis of a platinum(II) complex with 2-(4-methoxy-phenyl) imidazo [4,5-f]-[1,10] phenanthrolin and study of its antitumor activity. Eur J Med Chem 2014; 89:77-87. [PMID: 25462228 DOI: 10.1016/j.ejmech.2014.10.019] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Revised: 09/23/2014] [Accepted: 10/08/2014] [Indexed: 11/28/2022]
Abstract
A new platinum(II) complex of [Pt(II)(L) (pn)]Cl·2H2O (1) (pn = 1,3-propanediamine) with 2-(4-methoxy-phenyl)imidazo [4,5-f]-[1,10]phenanthrolin (H-L) was synthesized and characterized. In complex 1, the platinum adopts a four-coordinated square planar geometry. Complex 1 exhibited selective cytotoxicity against NCI-H460, BEL-7402, SK-OV-3, SK-OV-3/DDP and HeLa cell lines with IC50 values in the micromolar range (9.7-35.8 μM), but low cytotoxicity toward normal human liver HL-7702 cells. Complex 1 caused HeLa cell cycle arrest at S phase and it induced HeLa apoptosis by the activation of caspase-3/9. Various experiments showed that complex 1 preferred to bind with G-quadruplex in c-myc. Taken together, we found that complex 1 exerted its antitumor activity mainly via inhibiting telomerase by interaction with c-myc quadruplex and activation of caspase-3/9.
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Affiliation(s)
- Qi-Pin Qin
- State Key Laboratory Cultivation Base for the Chemistry and Molecular Engineering of Medicinal Resources, School of Chemistry & Pharmacy of Guangxi Normal University, Yucai Road 15, Guilin 541004, PR China
| | - Zhen-Feng Chen
- State Key Laboratory Cultivation Base for the Chemistry and Molecular Engineering of Medicinal Resources, School of Chemistry & Pharmacy of Guangxi Normal University, Yucai Road 15, Guilin 541004, PR China.
| | - Wen-Ying Shen
- State Key Laboratory Cultivation Base for the Chemistry and Molecular Engineering of Medicinal Resources, School of Chemistry & Pharmacy of Guangxi Normal University, Yucai Road 15, Guilin 541004, PR China
| | - Yan-Hua Jiang
- State Key Laboratory Cultivation Base for the Chemistry and Molecular Engineering of Medicinal Resources, School of Chemistry & Pharmacy of Guangxi Normal University, Yucai Road 15, Guilin 541004, PR China
| | - Dong Cao
- State Key Laboratory Cultivation Base for the Chemistry and Molecular Engineering of Medicinal Resources, School of Chemistry & Pharmacy of Guangxi Normal University, Yucai Road 15, Guilin 541004, PR China
| | - Yu-Lan Li
- State Key Laboratory Cultivation Base for the Chemistry and Molecular Engineering of Medicinal Resources, School of Chemistry & Pharmacy of Guangxi Normal University, Yucai Road 15, Guilin 541004, PR China
| | - Qing-Min Xu
- State Key Laboratory Cultivation Base for the Chemistry and Molecular Engineering of Medicinal Resources, School of Chemistry & Pharmacy of Guangxi Normal University, Yucai Road 15, Guilin 541004, PR China
| | - Yan-Cheng Liu
- State Key Laboratory Cultivation Base for the Chemistry and Molecular Engineering of Medicinal Resources, School of Chemistry & Pharmacy of Guangxi Normal University, Yucai Road 15, Guilin 541004, PR China
| | - Ke-Bin Huang
- State Key Laboratory Cultivation Base for the Chemistry and Molecular Engineering of Medicinal Resources, School of Chemistry & Pharmacy of Guangxi Normal University, Yucai Road 15, Guilin 541004, PR China
| | - Hong Liang
- State Key Laboratory Cultivation Base for the Chemistry and Molecular Engineering of Medicinal Resources, School of Chemistry & Pharmacy of Guangxi Normal University, Yucai Road 15, Guilin 541004, PR China.
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De Bonis ML, Ortega S, Blasco MA. SIRT1 is necessary for proficient telomere elongation and genomic stability of induced pluripotent stem cells. Stem Cell Reports 2014; 2:690-706. [PMID: 24936455 PMCID: PMC4050480 DOI: 10.1016/j.stemcr.2014.03.002] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2013] [Revised: 03/04/2014] [Accepted: 03/05/2014] [Indexed: 02/06/2023] Open
Abstract
The NAD-dependent deacetylase SIRT1 is involved in chromatin silencing and genome stability. Elevated SIRT1 levels in embryonic stem cells also suggest a role for SIRT1 in pluripotency. Murine SIRT1 attenuates telomere attrition in vivo and is recruited at telomeres in induced pluripotent stem cells (iPSCs). Because telomere elongation is an iPSC hallmark, we set out to study the role of SIRT1 in pluripotency in the setting of murine embryonic fibroblasts reprogramming into iPSCs. We find that SIRT1 is required for efficient postreprogramming telomere elongation, and that this effect is mediated by a c-MYC-dependent regulation of the mTert gene. We further demonstrate that SIRT1-deficient iPSCs accumulate chromosomal aberrations and show a derepression of telomeric heterochromatin. Finally, SIRT1-deficient iPSCs form larger teratomas that are poorly differentiated, highlighting a role for SIRT1 in exit from pluripotency. In summary, this work demonstrates a role for SIRT1 in the maintenance of pluripotency and modulation of differentiation.
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Affiliation(s)
- Maria Luigia De Bonis
- Telomeres and Telomerase Group, Molecular Oncology Program, Spanish National Cancer Centre (CNIO), Melchor Fernández Almagro 3, 28029 Madrid, Spain
| | - Sagrario Ortega
- Transgenic Mice Unit, Biotechnology Program, Spanish National Cancer Centre (CNIO), Melchor Fernández Almagro 3, 28029 Madrid, Spain
| | - Maria A Blasco
- Telomeres and Telomerase Group, Molecular Oncology Program, Spanish National Cancer Centre (CNIO), Melchor Fernández Almagro 3, 28029 Madrid, Spain
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17
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Islam MA, Thomas SD, Murty VV, Sedoris KJ, Miller DM. c-Myc quadruplex-forming sequence Pu-27 induces extensive damage in both telomeric and nontelomeric regions of DNA. J Biol Chem 2014; 289:8521-31. [PMID: 24464582 DOI: 10.1074/jbc.m113.505073] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Quadruplex-forming DNA sequences are present throughout the eukaryotic genome, including in telomeric DNA. We have shown that the c-Myc promoter quadruplex-forming sequence Pu-27 selectively kills transformed cells (Sedoris, K. C., Thomas, S. D., Clarkson, C. R., Muench, D., Islam, A., Singh, R., and Miller, D. M. (2012) Genomic c-Myc quadruplex DNA selectively kills leukemia. Mol. Cancer Ther. 11, 66-76). In this study, we show that Pu-27 induces profound DNA damage, resulting in striking chromosomal abnormalities in the form of chromatid or chromosomal breaks, radial formation, and telomeric DNA loss, which induces γ-H2AX in U937 cells. Pu-27 down-regulates telomeric shelterin proteins, DNA damage response mediators (RAD17 and RAD50), double-stranded break repair molecule 53BP1, G2 checkpoint regulators (CHK1 and CHK2), and anti-apoptosis gene survivin. Interestingly, there are no changes of DNA repair molecules H2AX, BRCA1, and the telomere maintenance gene, hTERT. ΔB-U937, where U937 cells stably transfected with deleted basic domain of TRF2 is partially sensitive to Pu-27 but exhibits no changes in expression of shelterin proteins. However, there is an up-regulation of CHK1, CHK2, H2AX, BRCA1, and survivin. Telomere dysfunction-induced foci assay revealed co-association of TRF1with γ-H2AX in ATM deficient cells, which are differentially sensitive to Pu-27 than ATM proficient cells. Alt (alternating lengthening of telomere) cells are relatively resistant to Pu-27, but there are no significant changes of telomerase activity in both Alt and non-Alt cells. Lastly, we show that this Pu-27-mediated sensitivity is p53-independent. The data therefore support two conclusions. First, Pu-27 induces DNA damage within both telomeric and nontelomeric regions of the genome. Second, Pu-27-mediated telomeric damage is due, at least in part, to compromise of the telomeric shelterin protein complex.
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Affiliation(s)
- Md Ashraful Islam
- From the Department of Medicine and Molecular Targets Program, James Graham Brown Cancer Center, University of Louisville, Louisville, Kentucky 40202 and
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18
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Wu XQ, Huang C, He X, Tian YY, Zhou DX, He Y, Liu XH, Li J. Feedback regulation of telomerase reverse transcriptase: new insight into the evolving field of telomerase in cancer. Cell Signal 2013; 25:2462-8. [DOI: 10.1016/j.cellsig.2013.08.009] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Accepted: 08/23/2013] [Indexed: 01/07/2023]
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19
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Bernardes de Jesus B, Vera E, Schneeberger K, Tejera AM, Ayuso E, Bosch F, Blasco MA. Telomerase gene therapy in adult and old mice delays aging and increases longevity without increasing cancer. EMBO Mol Med 2012; 4:691-704. [PMID: 22585399 PMCID: PMC3494070 DOI: 10.1002/emmm.201200245] [Citation(s) in RCA: 290] [Impact Index Per Article: 24.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2012] [Revised: 03/29/2012] [Accepted: 03/30/2012] [Indexed: 12/15/2022] Open
Abstract
A major goal in aging research is to improve health during aging. In the case of mice, genetic manipulations that shorten or lengthen telomeres result, respectively, in decreased or increased longevity. Based on this, we have tested the effects of a telomerase gene therapy in adult (1 year of age) and old (2 years of age) mice. Treatment of 1- and 2-year old mice with an adeno associated virus (AAV) of wide tropism expressing mouse TERT had remarkable beneficial effects on health and fitness, including insulin sensitivity, osteoporosis, neuromuscular coordination and several molecular biomarkers of aging. Importantly, telomerase-treated mice did not develop more cancer than their control littermates, suggesting that the known tumorigenic activity of telomerase is severely decreased when expressed in adult or old organisms using AAV vectors. Finally, telomerase-treated mice, both at 1-year and at 2-year of age, had an increase in median lifespan of 24 and 13%, respectively. These beneficial effects were not observed with a catalytically inactive TERT, demonstrating that they require telomerase activity. Together, these results constitute a proof-of-principle of a role of TERT in delaying physiological aging and extending longevity in normal mice through a telomerase-based treatment, and demonstrate the feasibility of anti-aging gene therapy.
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Affiliation(s)
- Bruno Bernardes de Jesus
- Telomeres and Telomerase Group, Molecular Oncology Program, Spanish National Cancer Centre (CNIO), Madrid, Spain
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20
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Liu J, Liu M, Ye X, Liu K, Huang J, Wang L, Ji G, Liu N, Tang X, Baltz JM, Keefe DL, Liu L. Delay in oocyte aging in mice by the antioxidant N-acetyl-L-cysteine (NAC). Hum Reprod 2012; 27:1411-20. [PMID: 22357770 DOI: 10.1093/humrep/des019] [Citation(s) in RCA: 115] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
BACKGROUND Ovarian aging is associated with declining numbers and quality of oocytes and follicles. Oxidative stress by reactive oxygen species (ROS) contributes to somatic aging in general, and also has been implicated in reproductive aging. Telomere shortening is also involved in aging, and telomeres are particularly susceptible to ROS-induced damage. Previously, we have shown that antioxidant N-acetyl-L-cysteine (NAC) effectively rescues oocytes and embryos from ROS-induced telomere shortening and apoptosis in vitro. Using mice as models, we tested the hypothesis that reducing oxidative stress by NAC might prevent or delay ovarian aging in vivo. METHODS Initially, young females were treated with NAC in drinking water for 2 months and the quality of fertilized oocytes and early embryo development were evaluated. Next, young mice 1-1½ months old were treated for 1 year with NAC added in drinking water, and their fertility was analyzed starting at 6 months, as indicated by litter size, oocyte number and quality. The ovaries were also examined for telomere activity and length and the expression of selected genes related to aging and DNA damage. RESULTS Short-term treatment of mice for 2 months with NAC demonstrated that NAC improved the quality of fertilized oocytes and early embryo development. Mice treated with a long-term low concentration (0.1 mM) of NAC had increased litter sizes at the ages of 7-10 months compared with age-matched controls without NAC treatment. NAC also increased the quality of the oocytes from these older mice. Moreover, the expression of sirtuins was increased, telomerase activity was higher and telomere length was longer in the ovaries of mice treated with NAC compared with those of the control group. CONCLUSIONS These data suggest that appropriate treatment with the antioxidant NAC postpones the process of oocyte aging in mice.
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Affiliation(s)
- Jinmiao Liu
- Department of Cell Biology and Genetics, College of Life Sciences, State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin 300071, China
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21
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Wang F, Yin Y, Ye X, Liu K, Zhu H, Wang L, Chiourea M, Okuka M, Ji G, Dan J, Zuo B, Li M, Zhang Q, Liu N, Chen L, Pan X, Gagos S, Keefe DL, Liu L. Molecular insights into the heterogeneity of telomere reprogramming in induced pluripotent stem cells. Cell Res 2011; 22:757-68. [PMID: 22184006 DOI: 10.1038/cr.2011.201] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Rejuvenation of telomeres with various lengths has been found in induced pluripotent stem cells (iPSCs). Mechanisms of telomere length regulation during induction and proliferation of iPSCs remain elusive. We show that telomere dynamics are variable in mouse iPSCs during reprogramming and passage, and suggest that these differences likely result from multiple potential factors, including the telomerase machinery, telomerase-independent mechanisms and clonal influences including reexpression of exogenous reprogramming factors. Using a genetic model of telomerase-deficient (Terc(-/-) and Terc(+/-)) cells for derivation and passages of iPSCs, we found that telomerase plays a critical role in reprogramming and self-renewal of iPSCs. Further, telomerase maintenance of telomeres is necessary for induction of true pluripotency while the alternative pathway of elongation and maintenance by recombination is also required, but not sufficient. Together, several aspects of telomere biology may account for the variable telomere dynamics in iPSCs. Notably, the mechanisms employed to maintain telomeres during iPSC reprogramming are very similar to those of embryonic stem cells. These findings may also relate to the cloning field where these mechanisms could be responsible for telomere heterogeneity after nuclear reprogramming by somatic cell nuclear transfer.
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Affiliation(s)
- Fang Wang
- College of Life Sciences, Nankai University, Tianjin 300071, China
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22
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Ou TM, Lin J, Lu YJ, Hou JQ, Tan JH, Chen SH, Li Z, Li YP, Li D, Gu LQ, Huang ZS. Inhibition of cell proliferation by quindoline derivative (SYUIQ-05) through its preferential interaction with c-myc promoter G-quadruplex. J Med Chem 2011; 54:5671-9. [PMID: 21774525 DOI: 10.1021/jm200062u] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
G-Quadruplex is a special DNA secondary structure and present in many important regulatory regions in human genome, such as the telomeric end and the promoters of some oncogenes. Specially, different forms of G-quadruplexes exist in telomeric DNA and c-myc promoter and play important roles in the pathway of cell proliferation and senescence. The effects of G-quadruplex ligands for either telomeric or c-myc G-quadruplex in vitro have been widely studied, but the specificity of these effects in vivo is still unknown. In the present research, various experiments were carried out to study the effect of G-quadruplex ligand SYUIQ-05 on tumor cell lines and the mechanism of this effect. Our results showed that it preferred to bind with G-quadruplex in c-myc and had rather insignificant effect on G-quadruplex in telomere. Therefore, it is possible that this compound had its antitumor activity for cancer cells mainly through its interaction with c-myc quadruplex.
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Affiliation(s)
- Tian-Miao Ou
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou University City, Waihuan East Road 132, Guangzhou 510006, People's Republic of China
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23
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Li K, Zhang J, Ren JJ, Wang Q, Yang KY, Xiong ZJ, Mao YQ, Qi YY, Chen XW, Lan F, Wang XJ, Xiao HY, Lin P, Wei YQ. A novel zinc finger protein Zfp637 behaves as a repressive regulator in myogenic cellular differentiation. J Cell Biochem 2010; 110:352-62. [PMID: 20235149 DOI: 10.1002/jcb.22546] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Zinc finger proteins have been implicated as transcription factors in the differentiation and development of cells and tissues in higher organisms. The classical C2H2 zinc finger motif is one main type of motif of zinc finger proteins. Our previous studies have shown that Zfp637, which comprises six consecutively typical and one atypical C2H2 zinc finger motifs, is highly expressed in undifferentiated or poorly differentiated cell lines, but is moderately or slightly expressed in normal tissues. We have also demonstrated that Zfp637 can promote cell proliferation. However, its role in the regulation of cell differentiation remains unknown. We report here that endogenous Zfp637 as well as mTERT is expressed in proliferating C2C12 myoblasts and that their expression is downregulated during myogenic differentiation. Constitutive expression of Zfp637 in C2C12 myoblasts increased mTERT expression and telomerase activity, and promoted the progression of the cell cycle and cell proliferation. By contrast, endogenous repression of Zfp637 expression by RNA interference downregulated the mTERT gene and the activity of telomerase, and markedly reduced cell proliferation. Overexpression of Zfp637 also inhibited the expression of myogenic differentiation-specific genes such as MyoD and myogenin, and prevented C2C12 myoblast differentiation. Our results suggest that Zfp637 inhibits muscle differentiation through a defect in the cell cycle exit by potentially regulating mTERT expression in C2C12 myoblasts. This may provide a new research line for studying muscle differentiation.
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Affiliation(s)
- Kai Li
- Division of Geriatrics, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, People's Republic of China
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24
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Wang HB, Wang XW, Zhou G, Wang WQ, Sun YG, Yang SM, Fang DC. PinX1 inhibits telomerase activity in gastric cancer cells through Mad1/c-Myc pathway. J Gastrointest Surg 2010; 14:1227-34. [PMID: 20544396 DOI: 10.1007/s11605-010-1253-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/08/2010] [Accepted: 05/31/2010] [Indexed: 01/31/2023]
Abstract
INTRODUCTION The aim of this study was to investigate the role of Mad1/c-Myc in telomerase regulation in gastric cancer cells in order to gain insight into telomerase activity and to evaluate PinX1 as a putative inhibitor of gastric cancer. METHODS PinX1 and PinX1siRNA eukaryotic expression vectors were constructed by recombinant technology and transfected into gastric carcinoma cells using Lipofectamine 2000. Telomerase activity was measured by the telomeric repeat amplification protocol. Apoptosis of gastric cancer cells was analyzed by flow cytometry and transmission electron microscopy. Reverse transcription-polymerase chain reaction and Western blotting were used to assess the expression levels of PinX1 and Mad1/c-Myc. RESULTS We found that PinX1-negative gastric cancer cells showed significantly higher telomerase activity than did the PinX1-postive cells. PinX1-transfection reduced telomerase activity in PinX1-negative gastric cancer cells and exhibited an upregulation of Mad1 and downregulation of c-Myc expression. Pinx1 RNAi treatment led to downregulation of Mad1 and upregulation of c-Myc. CONCLUSION Suppression of telomerase activity mediated by PinX1 is involved in the Mad1/c-Myc pathway.
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Affiliation(s)
- Hong-bin Wang
- Department of Gastroenterology, Southwest Hospital, Third Military Medical University, Chongqing, 400038, China
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25
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Marion RM, Strati K, Li H, Tejera A, Schoeftner S, Ortega S, Serrano M, Blasco MA. Telomeres acquire embryonic stem cell characteristics in induced pluripotent stem cells. Cell Stem Cell 2009; 4:141-54. [PMID: 19200803 DOI: 10.1016/j.stem.2008.12.010] [Citation(s) in RCA: 364] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2008] [Revised: 11/11/2008] [Accepted: 12/30/2008] [Indexed: 10/21/2022]
Abstract
Telomere shortening is associated with organismal aging. iPS cells have been recently derived from old patients; however, it is not known whether telomere chromatin acquires the same characteristics as in ES cells. We show here that telomeres are elongated in iPS cells compared to the parental differentiated cells both when using four (Oct3/4, Sox2, Klf4, cMyc) or three (Oct3/4, Sox2, Klf4) reprogramming factors and both from young and aged individuals. We demonstrate genetically that, during reprogramming, telomere elongation is usually mediated by telomerase and that iPS telomeres acquire the epigenetic marks of ES cells, including a low density of trimethylated histones H3K9 and H4K20 and increased abundance of telomere transcripts. Finally, reprogramming efficiency of cells derived from increasing generations of telomerase-deficient mice shows a dramatic decrease in iPS cell efficiency, a defect that is restored by telomerase reintroduction. Together, these results highlight the importance of telomere biology for iPS cell generation and functionality.
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Affiliation(s)
- Rosa M Marion
- Telomeres and Telomerase Group, Molecular Oncology Program, Spanish National Cancer Centre, Melchor Fernández Almagro 3, Madrid, Spain
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26
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Tomás-Loba A, Flores I, Fernández-Marcos PJ, Cayuela ML, Maraver A, Tejera A, Borrás C, Matheu A, Klatt P, Flores JM, Viña J, Serrano M, Blasco MA. Telomerase reverse transcriptase delays aging in cancer-resistant mice. Cell 2008; 135:609-22. [PMID: 19013273 DOI: 10.1016/j.cell.2008.09.034] [Citation(s) in RCA: 295] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2008] [Revised: 06/18/2008] [Accepted: 09/15/2008] [Indexed: 12/28/2022]
Abstract
Telomerase confers limitless proliferative potential to most human cells through its ability to elongate telomeres, the natural ends of chromosomes, which otherwise would undergo progressive attrition and eventually compromise cell viability. However, the role of telomerase in organismal aging has remained unaddressed, in part because of the cancer-promoting activity of telomerase. To circumvent this problem, we have constitutively expressed telomerase reverse transcriptase (TERT), one of the components of telomerase, in mice engineered to be cancer resistant by means of enhanced expression of the tumor suppressors p53, p16, and p19ARF. In this context, TERT overexpression improves the fitness of epithelial barriers, particularly the skin and the intestine, and produces a systemic delay in aging accompanied by extension of the median life span. These results demonstrate that constitutive expression of Tert provides antiaging activity in the context of a mammalian organism.
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Affiliation(s)
- Antonia Tomás-Loba
- Telomeres and Telomerase Group, Molecular Oncology Program, Spanish National Cancer Centre CNIO, Madrid, Spain
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Abstract
Studies performed on various experimental model systems indicate that genetic interventions can increase longevity, even if in a highly protected laboratory condition. Generally, such interventions required partial or complete switching off of the gene and inhibiting the activity of its gene products, which normally have other well-defined roles in metabolic processes. Overexpression of some genes, such as stress response and antioxidant genes, in some model systems also extends their longevity. Such genetic interventions may not be easily applicable to humans without knowing their effects on human growth, development, maturation, reproduction and other characteristics. Studies on the association of single nucleotide polymorphisms and multiple polymorphisms (haplotype) in genes with human longevity have identified several genes whose frequencies increase or decrease with age. Whether genetic redesigning can be achieved in the wake of numerous and complex epigenetic factors that effectively determine the life course and the life span of an individual still appears to be a 'mission impossible'.
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Affiliation(s)
- S I S Rattan
- Laboratory of Cellular Ageing, Department of Molecular Biology, University of Aarhus, Aarhus, Denmark.
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28
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Abstract
MYC in human epidermal stem cells can stimulate differentiation rather than uncontrolled proliferation. This discovery was, understandably, greeted with scepticism by researchers. However, subsequent studies have confirmed that MYC can stimulate epidermal stem cells to differentiate and have shed light on the underlying mechanisms. Two concepts that are relevant to cancer have emerged: first, MYC regulates similar genes in different cell types, but the biological consequences are context-dependent; and second, MYC activation is not a simple 'on/off' switch - the cellular response depends on the strength and duration of MYC activity, which in turn is affected by the many cofactors and regulatory pathways with which MYC interacts.
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Affiliation(s)
- Fiona M Watt
- Cancer Research UK Cambridge Research Institute, Li Ka Shing Centre, Robinson Way, Cambridge CB2 0RE, UK.
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29
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De Cian A, Lacroix L, Douarre C, Temime-Smaali N, Trentesaux C, Riou JF, Mergny JL. Targeting telomeres and telomerase. Biochimie 2007; 90:131-55. [PMID: 17822826 DOI: 10.1016/j.biochi.2007.07.011] [Citation(s) in RCA: 477] [Impact Index Per Article: 28.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2007] [Accepted: 07/16/2007] [Indexed: 01/06/2023]
Abstract
Telomeres and telomerase represent, at least in theory, an extremely attractive target for cancer therapy. The objective of this review is to present the latest view on the mechanism(s) of action of telomerase inhibitors, with an emphasis on a specific class of telomere ligands called G-quadruplex ligands, and to discuss their potential use in oncology.
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Affiliation(s)
- Anne De Cian
- INSERM, U565, Acides nucléiques: dynamique, ciblage et fonctions biologiques, 43 rue Cuvier, CP26, Paris Cedex 05, F-75231, France
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