51
|
Valiati FE, Hizo GH, Pinto JV, Kauer-Sant`Anna M. The Possible Role of Telomere Length and Chemokines in the Aging Process: A Transdiagnostic Review in Psychiatry. CURRENT PSYCHIATRY RESEARCH AND REVIEWS 2019. [DOI: 10.2174/1573400515666190719155906] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Background:Psychiatric disorders are common, reaching a worldwide prevalence of 29.2%. They are associated with a high risk of premature death and with accelerated aging in clinical, molecular and neuroimaging studies. Recently, there is strong evidence suggesting a possible role of telomere length and chemokines in aging processes in psychiatric disorders.Objective:We aimed to review the literature on telomere length and chemokines and its association with early aging in mental illnesses on a transdiagnostic approach.Results:The review highlights the association between psychiatric disorders and early aging. Several independent studies have reported shorter telomere length and dysregulations on levels of circulating chemokines in schizophrenia, bipolar disorder, major depressive disorder, and anxiety disorders, suggesting a complex interaction between these markers in a transdiagnostic level. However, studies have investigated the inflammatory markers and telomere shortening separately and associated with a particular diagnosis, rather than as a transdiagnostic biological feature.Conclusion:There is consistent evidence supporting the relationship between accelerated aging, telomere length, and chemokines in mental disorders, but they have been studied individually. Thus, more research is needed to improve the knowledge of accelerated senescence and its biomarkers in psychiatry, not only individually in each diagnosis, but also based on a transdiagnostic perspective. Moreover, further research should try to elucidate how the intricate association between the chemokines and telomeres together may contribute to the aging process in psychiatric disorders.
Collapse
Affiliation(s)
- Fernanda Endler Valiati
- Laboratory of Molecular Psychiatry, Experimental Research Center, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil
| | - Gabriel Henrique Hizo
- Laboratory of Molecular Psychiatry, Experimental Research Center, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil
| | - Jairo Vinícius Pinto
- Laboratory of Molecular Psychiatry, Experimental Research Center, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil
| | - Márcia Kauer-Sant`Anna
- Laboratory of Molecular Psychiatry, Experimental Research Center, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil
| |
Collapse
|
52
|
Billard P, Poncet DA. Replication Stress at Telomeric and Mitochondrial DNA: Common Origins and Consequences on Ageing. Int J Mol Sci 2019; 20:ijms20194959. [PMID: 31597307 PMCID: PMC6801922 DOI: 10.3390/ijms20194959] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 10/04/2019] [Accepted: 10/05/2019] [Indexed: 12/12/2022] Open
Abstract
Senescence is defined as a stress-induced durable cell cycle arrest. We herein revisit the origin of two of these stresses, namely mitochondrial metabolic compromise, associated with reactive oxygen species (ROS) production, and replicative senescence, activated by extreme telomere shortening. We discuss how replication stress-induced DNA damage of telomeric DNA (telDNA) and mitochondrial DNA (mtDNA) can be considered a common origin of senescence in vitro, with consequences on ageing in vivo. Unexpectedly, mtDNA and telDNA share common features indicative of a high degree of replicative stress, such as G-quadruplexes, D-loops, RNA:DNA heteroduplexes, epigenetic marks, or supercoiling. To avoid these stresses, both compartments use similar enzymatic strategies involving, for instance, endonucleases, topoisomerases, helicases, or primases. Surprisingly, many of these replication helpers are active at both telDNA and mtDNA (e.g., RNAse H1, FEN1, DNA2, RecQ helicases, Top2α, Top2β, TOP3A, DNMT1/3a/3b, SIRT1). In addition, specialized telomeric proteins, such as TERT (telomerase reverse transcriptase) and TERC (telomerase RNA component), or TIN2 (shelterin complex), shuttle from telomeres to mitochondria, and, by doing so, modulate mitochondrial metabolism and the production of ROS, in a feedback manner. Hence, mitochondria and telomeres use common weapons and cooperate to resist/prevent replication stresses, otherwise producing common consequences, namely senescence and ageing.
Collapse
Affiliation(s)
- Pauline Billard
- Univ Lyon, Université Claude Bernard Lyon 1, INSERM 1052, CNRS 5286, Centre Léon Bérard, Centre de recherche en cancérologie de Lyon, 69008 Lyon, France.
- Institut de Biopathologie moléculaire, Centre de Bio-Pathologie Est, Groupement hospitalier Est, Hospices Civils de Lyon, 69500 Bron, France.
| | - Delphine A Poncet
- Univ Lyon, Université Claude Bernard Lyon 1, INSERM 1052, CNRS 5286, Centre Léon Bérard, Centre de recherche en cancérologie de Lyon, 69008 Lyon, France.
- Institut de Biopathologie moléculaire, Centre de Bio-Pathologie Est, Groupement hospitalier Est, Hospices Civils de Lyon, 69500 Bron, France.
| |
Collapse
|
53
|
Abstract
Telomeres, the protective ends of linear chromosomes, shorten throughout an individual's lifetime. Accumulation of critically short telomeres is proposed to be a primary molecular cause of aging and age-associated diseases. Mutations in telomere maintenance genes are associated with pathologies referred to as or telomeropathies. The rate of telomere shortening throughout life is determined by endogenous (genetic) and external (nongenetic) factors. Therapeutic strategies based on telomerase activation are being developed to treat and prevent telomere-associated diseases, namely aging-related diseases and telomeropathies. Here, we review the molecular mechanisms underlying telomere driven diseases with particular emphasis on cardiovascular diseases.
Collapse
Affiliation(s)
- Paula Martínez
- From the Telomeres and Telomerase Group, Molecular Oncology Program, Spanish National Cancer Centre (CNIO), Madrid, Spain
| | - Maria A Blasco
- From the Telomeres and Telomerase Group, Molecular Oncology Program, Spanish National Cancer Centre (CNIO), Madrid, Spain
| |
Collapse
|
54
|
Pooley KA, Dunning AM. DNA damage and hormone-related cancer: a repair pathway view. Hum Mol Genet 2019; 28:R180-R186. [DOI: 10.1093/hmg/ddz206] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Revised: 08/09/2019] [Accepted: 08/15/2019] [Indexed: 01/05/2023] Open
Abstract
Abstract
In this short review, we examine the overlap between genes known to be mutated in the germlines of individuals at risk of breast, ovarian and prostate cancers, and their positions in DNA damage repair pathways. Cancer risk mutations have been consistently reported in certain genes at the top of these pathways, but none have been reported in others. We consider whether some of these gene products are too crucial to life for mutations to be tolerated, whilst others, further down the pathways, are less essential.
Collapse
Affiliation(s)
- Karen A Pooley
- Centre for Cancer Genetic Epidemiology, Departments of Public Health and Primary Care, 2 Worts Causeway, Cambridge CB1 8RN, UK
| | - Alison M Dunning
- Oncology and Strangeways Research Laboratory, 2 Worts Causeway, Cambridge CB1 8RN, UK
| |
Collapse
|
55
|
Cho HY, Lee YA, Oh YS, Lee GJ, Jang YJ, Kim SK. Binding mode of a cationic porphyrin to parallel and antiparallel thrombin binding aptamer G-quadruplex. J Biomol Struct Dyn 2019; 38:2686-2692. [PMID: 31307279 DOI: 10.1080/07391102.2019.1642241] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The spectral properties of meso-tetrakis (N-methylpyridinium-4-yl)porphyrin (TMPyP) in the presence of parallel and antiparallel G-quadruplexes formed from a thrombin-binding aptamer G-quadruplex (5'-G3T2G3TGTG3T2G3) were investigated in this study. Red shift and hypochromism in the Soret absorption band of TMPyP were observed after binding to both parallel and antiparallel G-quadruplexes. The extent of changes in the absorption spectra were similar for both conformers. No circular dichroism spectrum was induced in the Soret region for both parallel and antiparallel G-quadruplexes. This is suggest that there is no or very weak interaction between electric transitions of nucleobases and porphyrin molecule. The accessibility of the neutral quencher I2 to the G-quadruplex-bound TMPyP was similar for both parallel and antiparallel G-quadruplexes. All these observations suggest that TMPyP was bound at the outside of the quadruplexes, and conceivably interacted with the phosphate group via a weak electrostatic interaction.Communicated by Ramaswamy H. Sarma.
Collapse
Affiliation(s)
- Ha Young Cho
- Department of Chemistry, Yeungnam University, Gyeongsan, Republic of Korea
| | - Young-Ae Lee
- Department of Chemistry, Yeungnam University, Gyeongsan, Republic of Korea
| | - Ye Sol Oh
- Department of Chemistry, Yeungnam University, Gyeongsan, Republic of Korea
| | - Gil Jun Lee
- Department of Safety and Disaster Prevention Engineering, Kyungwoon University, Gumi, Republic of Korea
| | - Yoon Jung Jang
- College of Basis Education, Yeungnam University, Gyeongsan, Republic of Korea
| | - Seog K Kim
- Department of Chemistry, Yeungnam University, Gyeongsan, Republic of Korea
| |
Collapse
|
56
|
FEZF1-AS1: a novel vital oncogenic lncRNA in multiple human malignancies. Biosci Rep 2019; 39:BSR20191202. [PMID: 31175144 PMCID: PMC6591563 DOI: 10.1042/bsr20191202] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 06/06/2019] [Accepted: 06/07/2019] [Indexed: 12/24/2022] Open
Abstract
Long noncoding RNAs (LncRNAs) refer to the RNA with a length of >200 nucleotides, which lack or have no open reading coding frame and have higher tissue and organ specificity compared with the protein coding genes. A surging number of studies have shown that lncRNA is involved in numerous essential regulatory processes, such as X chromosome silencing, genomic imprinting, chromatin modification, transcriptional activation, transcriptional interference and nuclear transport, which are closely related to the occurrence and development of human malignancies. FEZ family Zinc Finger 1-Antisense RNA 1 (FEZF1-AS1) of FEZ family is a recently discovered lncRNA. FEZF1-AS1 is highly expressed in pancreatic cancer, colorectal cancer, lung adenocarcinoma and other human malignancies, and is associated with poor prognosis. As an oncogene, it plays crucial role in the proliferation, migration, invasion and Warburg effect of various tumor cells. In addition, FEZF1-AS1 is also involved in the regulation of multiple signal pathways such as epithelial–mesenchymal transition (EMT), signal transducer and activator of transcription 3 (STAT3) and Wnt/ β-catenin. In this paper, the recent research progress of FEZF1-AS1 in tumorigenesis and development is reviewed systematically.
Collapse
|
57
|
Wu G, Chen L, Liu W, Yang D. Molecular Recognition of the Hybrid-Type G-Quadruplexes in Human Telomeres. Molecules 2019; 24:molecules24081578. [PMID: 31013622 PMCID: PMC6514847 DOI: 10.3390/molecules24081578] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2019] [Revised: 04/17/2019] [Accepted: 04/19/2019] [Indexed: 12/13/2022] Open
Abstract
G-quadruplex (G4) DNA secondary structures formed in human telomeres have been shown to inhibit cancer-specific telomerase and alternative lengthening of telomere (ALT) pathways. Thus, human telomeric G-quadruplexes are considered attractive targets for anticancer drugs. Human telomeric G-quadruplexes are structurally polymorphic and predominantly form two hybrid-type G-quadruplexes, namely hybrid-1 and hybrid-2, under physiologically relevant solution conditions. To date, only a handful solution structures are available for drug complexes of human telomeric G-quadruplexes. In this review, we will describe two recent solution structural studies from our labs. We use NMR spectroscopy to elucidate the solution structure of a 1:1 complex between a small molecule epiberberine and the hybrid-2 telomeric G-quadruplex, and the structures of 1:1 and 4:2 complexes between a small molecule Pt-tripod and the hybrid-1 telomeric G-quadruplex. Structural information of small molecule complexes can provide important information for understanding small molecule recognition of human telomeric G-quadruplexes and for structure-based rational drug design targeting human telomeric G-quadruplexes.
Collapse
Affiliation(s)
- Guanhui Wu
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, 575 W Stadium Ave, West Lafayette, IN 47907, USA.
| | - Luying Chen
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, 575 W Stadium Ave, West Lafayette, IN 47907, USA.
| | - Wenting Liu
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, 575 W Stadium Ave, West Lafayette, IN 47907, USA.
| | - Danzhou Yang
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, 575 W Stadium Ave, West Lafayette, IN 47907, USA.
- Purdue Center for Cancer Research, 201 S University St, West Lafayette, IN 47906, USA.
- Purdue Institute for Drug Discovery, 720 Clinic Dr, West Lafayette, IN 47907, USA.
| |
Collapse
|
58
|
Shastrula PK, Sierra I, Deng Z, Keeney F, Hayden JE, Lieberman PM, Janicki SM. PML is recruited to heterochromatin during S phase and represses DAXX-mediated histone H3.3 chromatin assembly. J Cell Sci 2019; 132:jcs.220970. [PMID: 30796101 DOI: 10.1242/jcs.220970] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Accepted: 02/09/2019] [Indexed: 12/18/2022] Open
Abstract
The incorporation of the histone H3 variant, H3.3, into chromatin by the H3.3-specific chaperone DAXX and the ATP-dependent chromatin remodeling factor ATRX is a critical mechanism for silencing repetitive DNA. DAXX and ATRX are also components of promyelocytic nuclear bodies (PML-NBs), which have been identified as sites of H3.3 chromatin assembly. Here, we use a transgene array that can be visualized in single living cells to investigate the mechanisms that recruit PML-NB proteins (i.e. PML, DAXX, ATRX, and SUMO-1, SUMO-2 and SUMO-3) to heterochromatin and their functions in H3.3 chromatin assembly. We show that DAXX and PML are recruited to the array through distinct SUMOylation-dependent mechanisms. Additionally, PML is recruited during S phase and its depletion increases H3.3 deposition. Since this effect is abrogated when PML and DAXX are co-depleted, it is likely that PML represses DAXX-mediated H3.3 chromatin assembly. Taken together, these results suggest that, at heterochromatin, PML-NBs coordinate H3.3 chromatin assembly with DNA replication, which has important implications for understanding how transcriptional silencing is established and maintained.
Collapse
Affiliation(s)
- Prashanth Krishna Shastrula
- The Wistar Institute, 3601 Spruce Street, Philadelphia, PA 19104, USA.,University of the Sciences in Philadelphia, Department of Biological Sciences, 600 South 43rd Street, Philadelphia, PA 19104, USA
| | - Isabel Sierra
- The Wistar Institute, 3601 Spruce Street, Philadelphia, PA 19104, USA
| | - Zhong Deng
- The Wistar Institute, 3601 Spruce Street, Philadelphia, PA 19104, USA
| | - Frederick Keeney
- The Wistar Institute, 3601 Spruce Street, Philadelphia, PA 19104, USA
| | - James E Hayden
- The Wistar Institute, 3601 Spruce Street, Philadelphia, PA 19104, USA
| | - Paul M Lieberman
- The Wistar Institute, 3601 Spruce Street, Philadelphia, PA 19104, USA
| | - Susan M Janicki
- The Wistar Institute, 3601 Spruce Street, Philadelphia, PA 19104, USA
| |
Collapse
|
59
|
Sun Y, Ji Y, Wang D, Wang J, Liu D. Stabilization of an intermolecular i-motif by lipid modification of cytosine-oligodeoxynucleotides. Org Biomol Chem 2019; 16:4857-4863. [PMID: 29926887 DOI: 10.1039/c8ob00920a] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
This paper describes the stabilization of an intermolecular i-motif by lipophilic modification on the 3'-terminus of oligonucleotides. The hydrophobic aliphatic chain connected at the 3'-terminus of a trinucleotide (dC)3 promoted the formation of an i-motif and significantly enhanced the quadruplex's stability. The impact of lipophilic modification on i-motif's thermal stability was studied by UV-thermal denaturation melting experiments and isothermal titration calorimetry. We found that alkyl chains containing more than 14 carbon atoms could elevate the i-motif structure's stability in a wide range of pH and concentrations.
Collapse
Affiliation(s)
- Yawei Sun
- State Key Laboratory of Heavy Oil Processing, College of Chemical Engineering, China University of Petroleum (Huadong), Qingdao, 258000, China.
| | | | | | | | | |
Collapse
|
60
|
Shao L. DNA Damage Response Signals Transduce Stress From Rheumatoid Arthritis Risk Factors Into T Cell Dysfunction. Front Immunol 2018; 9:3055. [PMID: 30619377 PMCID: PMC6306440 DOI: 10.3389/fimmu.2018.03055] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Accepted: 12/10/2018] [Indexed: 12/18/2022] Open
Abstract
Rheumatoid arthritis (RA) is an autoimmune-mediated disease that is associated with significant cartilage damage and immunosenescence. Despite decades of research, the major signal pathways that initiate RA are still unclear. The DNA damage response (DDR) is a specific and hierarchical network that includes cell cycle checkpoints, DNA repair, and DNA-damage tolerance pathways. Recent studies suggest that this condition is associated with deficits in telomere maintenance and overall genomic instability in the T cells of RA patients. Analysis of the underlying mechanisms has revealed defects in DDR pathways. Particularly, the DNA repair enzyme, ataxia telangiectasia mutated (ATM), is downregulated, which leaves the damaged DNA breaks in RA-associated T cells unrepaired and pushes them to apoptosis, exhausts the T cell pool, and promotes the arthritogenesis effector function of T cells. This review discusses recent advancements and illustrates that risk factors for RA, such as viral infections, environmental events, and genetic risk loci are combat with DDR signals, and the impaired DDR response of RA-associated T cells, in turn, triggers disease-related phenotypes. Therefore, DDR is the dominant signal that converts genetic and environmental stress to RA-related immune dysfunction. Understanding the orchestration of RA pathogenesis by DDR signals would further our current knowledge of RA and provide novel avenues in RA therapy.
Collapse
Affiliation(s)
- Lan Shao
- The Center for Translational Medicine, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| |
Collapse
|
61
|
Sabale P, Ambi UB, Srivatsan SG. Clickable PNA Probes for Imaging Human Telomeres and Poly(A) RNAs. ACS OMEGA 2018; 3:15343-15352. [PMID: 30556003 PMCID: PMC6289544 DOI: 10.1021/acsomega.8b02550] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Accepted: 10/31/2018] [Indexed: 05/10/2023]
Abstract
The ability to bind strongly to complementary nucleic acid sequences, invade complex nucleic acid structures, and resist degradation by cellular enzymes has made peptide nucleic acid (PNA) oligomers as very useful hybridization probes in molecular diagnosis. For such applications, the PNA oligomers have to be labeled with appropriate reporters as they lack intrinsic labels that can be used in biophysical assays. Although solid-phase synthesis is commonly used to attach reporters onto PNA, development of milder and modular labeling methods will provide access to PNA oligomers labeled with a wider range of biophysical tags. Here, we describe the establishment of a postsynthetic modification strategy based on bioorthogonal chemical reactions in functionalizing PNA oligomers in solution with a variety of tags. A toolbox composed of alkyne- and azide-modified monomers were site-specifically incorporated into PNA oligomers and postsynthetically click-functionalized with various tags, ranging from sugar, amino acid, biotin, to fluorophores, by using copper(I)-catalyzed azide-alkyne cycloaddition, strain-promoted azide-alkyne cycloaddition, and Staudinger ligation reactions. As a proof of utility of this method, fluorescent PNA hybridization probes were developed and used in imaging human telomeres in chromosomes and poly(A) RNAs in cells. Taken together, this simple approach of generating a wide range of functional PNA oligomers will expand the use of PNA in molecular diagnosis.
Collapse
|
62
|
The Effect of Ethanol on Telomere Dynamics and Regulation in Human Cells. Cells 2018; 7:cells7100169. [PMID: 30326633 PMCID: PMC6210749 DOI: 10.3390/cells7100169] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Revised: 10/07/2018] [Accepted: 10/08/2018] [Indexed: 01/21/2023] Open
Abstract
Telomeres (TLs) protect chromosome ends from chromosomal fusion and degradation, thus conferring genomic stability, and play crucial roles in cellular aging and disease. Recent studies have found a correlation between environmental, physiological and even mental stresses on TL dynamics in humans. However, the causal relationship between stress and TL length and the molecular mechanisms underlying that relationship are far from being understood. This study describes the effect of moderate concentrations of ethanol, equivalent to social drinking, on human TL dynamics and partially elucidates the mechanism mediating this effect. The exposure of Immortalized human foreskin fibroblast, primary human foreskin fibroblast and human hepatocellular carcinoma cells to 25 mM ethanol for one week moderately shortened telomeres in all cells. Similar TL shortening was obtained following cells’ exposure to 25 µM acetaldehyde (AcH) and to a much lower extent after exposure to 4-methylpyrazolean, an inhibitor of alcoholdehydrogenase, suggesting that AcH plays a key role in ethanol-dependent telomere shortening. Telomerase activity was not involved in this effect. TRF2 and several TRF2 binding proteins increased their binding to TLs after ethanol treatment, implying their involvement in this effect. The methylation status of several sub-telomeric regions increased in response to EtOH exposure. Gene expression profiling showed distinct patterns in cells treated with EtOH and in cells recovered from EtOH. In addition to cellular ageing, the described telomere shortening may contribute to the carcinogenic potential of acute alcohol consumption; both are associated with the shortening of TLs and provide new insights regarding the moderate consumption of alcohol referred to as “social drinking.”
Collapse
|
63
|
The role of telomere shortening in carcinogenesis: A hybrid stochastic-deterministic approach. J Theor Biol 2018; 460:144-152. [PMID: 30315815 DOI: 10.1016/j.jtbi.2018.09.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Revised: 07/27/2018] [Accepted: 09/03/2018] [Indexed: 11/21/2022]
Abstract
Genome instability is a characteristic of most cancers, contributing to the acquisition of genetic alterations that drive tumor progression. One important source of genome instability is linked to telomere dysfunction in cells with critically short telomeres that lack p53-mediated surveillance of genomic integrity. Here we research the probability that cancer emerges through an evolutionary pathway that includes a telomere-induced phase of genome instability. To implement our models we use a hybrid stochastic-deterministic approach, which allows us to perform large numbers of simulations using biologically realistic population sizes and mutation rates, circumventing the traditional limitations of fully stochastic algorithms. The hybrid methodology should be easily adaptable to a wide range of evolutionary problems. In particular, we model telomere shortening and the acquisition of two mutations: Telomerase activation and p53 inactivation. We find that the death rate of unstable cells, and the number of cell divisions that p53 mutants can sustain beyond the normal senescence setpoint determine the likelihood that the first double mutant originates in a cell with telomere-induced instability. The model has applications to an influential telomerase-null mouse model and p16 silenced human cells. We end by discussing algorithmic performance and a measure for the accuracy of the hybrid approximation.
Collapse
|
64
|
Harvey A, Mielke N, Grimstead JW, Jones RE, Nguyen T, Mueller M, Baird DM, Hendrickson EA. PARP1 is required for preserving telomeric integrity but is dispensable for A-NHEJ. Oncotarget 2018; 9:34821-34837. [PMID: 30410680 PMCID: PMC6205175 DOI: 10.18632/oncotarget.26201] [Citation(s) in RCA: 10] [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: 07/22/2018] [Accepted: 09/15/2018] [Indexed: 01/07/2023] Open
Abstract
Poly-ADP ribose polymerase 1 (PARP1) is clinically important because of its synthetic lethality with breast cancer allele 1 and 2 mutations, which are causative for inherited breast and ovarian cancers. Biochemically, PARP1 is a single-stranded DNA break repair protein that is needed for preserving genomic integrity. In addition, PARP1 has been implicated in a veritable plethora of additional cellular pathways and thus its precise contribution(s) to human biology has remained obscure. To help address this deficiency, we utilized gene editing to construct genetically-null PARP1 human cancer cells. We found a minor role for PARP1 in an alternative form of DNA double-strand break (DSB) repair, but only when these cells were deficient for the classical form of DSB repair. Despite being proficient for DSB repair, however, cell cycle progression defects and elevated endogenous DNA damage signaling were observed. These deficiencies were instead linked to telomere defects, where PARP1 -/- cells had short telomeres that co-localized with markers of endogenous DNA damage and were compromised in their ability to escape a telomere-driven crisis. Our data suggest that while PARP1 does not participate significantly in DNA DSB repair itself, it does prevent the incidence of telomeric DSBs, which, in turn, can drive genomic instability.
Collapse
Affiliation(s)
- Adam Harvey
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota Medical School, Minneapolis, Minnesota 55455, USA
| | - Nicholas Mielke
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota Medical School, Minneapolis, Minnesota 55455, USA
| | - Julia W. Grimstead
- Division of Cancer and Genetics, School of Medicine, Cardiff University, Heath Park, Cardiff CF14 4XN, United Kingdom
| | - Rhiannon E. Jones
- Division of Cancer and Genetics, School of Medicine, Cardiff University, Heath Park, Cardiff CF14 4XN, United Kingdom
| | - Thanh Nguyen
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota Medical School, Minneapolis, Minnesota 55455, USA
| | - Matthew Mueller
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota Medical School, Minneapolis, Minnesota 55455, USA
| | - Duncan M. Baird
- Division of Cancer and Genetics, School of Medicine, Cardiff University, Heath Park, Cardiff CF14 4XN, United Kingdom
| | - Eric A. Hendrickson
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota Medical School, Minneapolis, Minnesota 55455, USA
| |
Collapse
|
65
|
Piekna-Przybylska D, Maggirwar SB. CD4+ memory T cells infected with latent HIV-1 are susceptible to drugs targeting telomeres. Cell Cycle 2018; 17:2187-2203. [PMID: 30198385 DOI: 10.1080/15384101.2018.1520568] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The population of HIV reservoir in infected person is very small, but extremely long-lived and is a major obstacle for an HIV cure. We previously showed that cells with established HIV latency have deficiencies in DNA damage response (DDR). Here, we investigated ability of HIV-1 to interfere with telomere maintenance, and the effects of targeting telomeres on latently infected cells. Our results show that telomeres are elongated in cultured primary memory CD4 + T cells (TCM) after HIV-1 infection and when virus latency is established. Similarly, much longer telomeres were found in several Jurkat-derived latently infected cell lines, indicating that virus stimulates telomere elongation. Exposing primary CD4+ TCM cells to BRACO19, an agent targeting telomeres, resulted in a higher rate of apoptosis for infected cultures at day 3 post-infection, during HIV-1 latency and for PMA-stimulated cultures with low level of HIV-1 reactivation. Importantly, BRACO19 induced apoptosis in infected cells with potency similar to etoposide and camptothecin, whereas uninfected cells were less affected by BRACO19. We also determined that apoptosis induced by BRACO19 is not caused by telomeres shortening, but is related to formation of gamma-H2AX, implicating DNA damage or uncapping of telomeres, which triggers genome instability. In conclusion, our results indicate that HIV-1 stimulates telomere elongation during latency, suggesting that HIV reservoir has greater capacity for clonal expansion and extended lifespan. Higher rates of apoptosis in response to BRACO19 treatment suggest that HIV reservoirs are more susceptible to targeting telomere maintenance and to inhibitors targeting DDR, which is also involved in stabilizing telomeres.
Collapse
Affiliation(s)
- Dorota Piekna-Przybylska
- a Department of Microbiology and Immunology, School of Medicine and Dentistry , University of Rochester , Rochester , NY , USA
| | - Sanjay B Maggirwar
- a Department of Microbiology and Immunology, School of Medicine and Dentistry , University of Rochester , Rochester , NY , USA
| |
Collapse
|
66
|
Seshadri N, Sandhu S, Wu X, Liu W, Ding H. Generation of an Rtel1-CreERT2 knock-in mouse model for lineage tracing RTEL1+ stem cells during development. Transgenic Res 2018; 27:571-578. [PMID: 30196476 DOI: 10.1007/s11248-018-0093-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Accepted: 08/31/2018] [Indexed: 10/28/2022]
Abstract
Regulator of telomere length 1 (RTEL1) DNA helicase has been demonstrated to be essential for the maintenance of telomeres and genomic stability. This function of RTEL1 could be required for protecting stem cells from genomic mutations as suggested by its selective expression in stem cell-zones, as well as by RTEL1 mutations identified in Hoyeraal-Hreidarsson syndrome, a severe dyskeratosis congenita that targets primarily stem cell compartments. As a first step to establish a role of RTEL1 in stem cells, we generated an Rtel1CreERT2 mouse allele in which a tamoxifen-inducible Cre (CreERT2) cDNA was specifically knocked into the Rtel1 genomic locus and controlled by the endogenous Rtel1 regulatory elements. By crossing with a Cre-dependent LacZ reporter mouse strain (R26RLacZ), we further demonstrated that Cre activity in Rtel1CreERT2 mice could be specifically induced by tamoxifen, which allowed the fate of RTEL1+ cells to be traced at various stages of development. Using this tracing assay, we showed for the first time that RTEL1+ cells in the intestine and the testis can act as stem cells that have the capacity to self-renew and differentiate into progeny cells. Therefore, the Rtel1CreERT2 mice generated in this study will be a valuable transgenic tool to explore the function of RTEL1 in stem cells.
Collapse
Affiliation(s)
- Nivedita Seshadri
- Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, MB, Canada
| | - Sumit Sandhu
- Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, MB, Canada.,Department of Microbiology and Molecular Genetics, University of California, Davis, Davis, USA
| | - Xiaoli Wu
- Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, MB, Canada
| | - Wenjun Liu
- Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, MB, Canada
| | - Hao Ding
- Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, MB, Canada.
| |
Collapse
|
67
|
Merta TJ, Geacintov NE, Shafirovich V. Generation of 8-oxo-7,8-dihydroguanine in G-Quadruplexes Models of Human Telomere Sequences by One-electron Oxidation. Photochem Photobiol 2018; 95:244-251. [PMID: 29679477 PMCID: PMC6196120 DOI: 10.1111/php.12926] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Accepted: 04/04/2018] [Indexed: 12/16/2022]
Abstract
The mechanistic aspects of one-electron oxidation of G-quadruplexes in the basket (Na+ ions) and hybrid (K+ ions) conformations were investigated by transient absorption laser kinetic spectroscopy and HPLC detection of the 8-oxo-7,8-dihydroguanine (8-oxoG) oxidation product. The photo-induced one-electron abstraction from G-quadruplexes was initiated by sulfate radical anions (SO4 ˙- ) derived from the photolysis of persulfate ions by 308 nm excimer laser pulses. In neutral aqueous solutions (pH 7.0), the transient absorbance of neutral guanine radicals, G(-H)˙, is observed following the complete decay of SO4 ˙- radicals (~10 μs after the actinic laser flash). In both basket and hybrid conformations, the G(-H)˙ decay is biphasic with one component decaying with a lifetime of ~0.1 ms, and the other with a lifetime of 20-30 ms. The fast decay component (~0.1 ms) in G-quadruplexes is correlated with the formation of 8-oxoG lesions. We propose that in G-quadruplexes, G(-H)˙ radicals retain radical cation character by sharing the N1-proton with the O6 -atom of G in the [G˙+ : G] Hoogsteen base pair; this [G(-H)˙: H+ G <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mo>⇄</mml:mo></mml:math> G˙+ : G] leads to the hydration of G˙+ radical cation within the millisecond time domain, and is followed by the formation of the 8-oxoG lesions.
Collapse
Affiliation(s)
- Tomasz J Merta
- Chemistry Program, NYU Shanghai, Pudong Xinqu, Shanghai Shi, China
| | - Nicholas E Geacintov
- Chemistry Program, NYU Shanghai, Pudong Xinqu, Shanghai Shi, China.,Chemistry Department, New York University, New York, NY
| | | |
Collapse
|
68
|
Qu F, Chen Z, You J, Song C. A colorimetric platform for sensitively differentiating telomere DNA with different lengths, monitoring G-quadruplex and dsDNA based on silver nanoclusters and unmodified gold nanoparticles. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2018; 196:148-154. [PMID: 29444496 DOI: 10.1016/j.saa.2018.02.024] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Revised: 01/30/2018] [Accepted: 02/07/2018] [Indexed: 06/08/2023]
Abstract
Human telomere DNA plays a vital role in genome integrity control and carcinogenesis as an indication for extensive cell proliferation. Herein, silver nanoclusters (Ag NCs) templated by polymer and unmodified gold nanoparticles (Au NPs) are designed as a new colorimetric platform for sensitively differentiating telomere DNA with different lengths, monitoring G-quadruplex and dsDNA. Ag NCs can produce the aggregation of Au NPs, so the color of Au NPs changes to blue and the absorption peak moves to 700nm. While the telomere DNA can protect Au NPs from aggregation, the color turns to red again and the absorption band blue shift. Benefiting from the obvious color change, we can differentiate the length of telomere DNA by naked eyes. As the length of telomere DNA is longer, the variation of color becomes more noticeable. The detection limits of telomere DNA containing 10, 22, 40, 64 bases are estimated to be 1.41, 1.21, 0.23 and 0.22nM, respectively. On the other hand, when telomere DNA forms G-quadruplex in the presence of K+, or dsDNA with complementary sequence, both G-quadruplex and dsDNA can protect Au NPs better than the unfolded telomere DNA. Hence, a new colorimetric platform for monitoring structure conversion of DNA is established by Ag NCs-Au NPs system, and to prove this type of application, a selective K+ sensor is developed.
Collapse
Affiliation(s)
- Fei Qu
- The Key Laboratory of Life-Organic Analysis, Qufu Normal University, Qufu 273165, Shandong, China; Key Laboratory of Pharmaceutical Intermediates and Analysis of Natural Medicine, Qufu Normal University, Qufu 273165, Shandong, China.
| | - Zeqiu Chen
- The Key Laboratory of Life-Organic Analysis, Qufu Normal University, Qufu 273165, Shandong, China; Key Laboratory of Pharmaceutical Intermediates and Analysis of Natural Medicine, Qufu Normal University, Qufu 273165, Shandong, China
| | - Jinmao You
- The Key Laboratory of Life-Organic Analysis, Qufu Normal University, Qufu 273165, Shandong, China; Key Laboratory of Pharmaceutical Intermediates and Analysis of Natural Medicine, Qufu Normal University, Qufu 273165, Shandong, China; Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining 810001, China
| | - Cuihua Song
- The Key Laboratory of Life-Organic Analysis, Qufu Normal University, Qufu 273165, Shandong, China; Key Laboratory of Pharmaceutical Intermediates and Analysis of Natural Medicine, Qufu Normal University, Qufu 273165, Shandong, China.
| |
Collapse
|
69
|
Matmati S, Vaurs M, Escandell JM, Maestroni L, Nakamura TM, Ferreira MG, Géli V, Coulon S. The fission yeast Stn1-Ten1 complex limits telomerase activity via its SUMO-interacting motif and promotes telomeres replication. SCIENCE ADVANCES 2018; 4:eaar2740. [PMID: 29774234 PMCID: PMC5955624 DOI: 10.1126/sciadv.aar2740] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Accepted: 03/29/2018] [Indexed: 06/01/2023]
Abstract
Mammalian CST (CTC1-STN1-TEN1) complex fulfills numerous functions including rescue of the stalled replication forks and termination of telomerase action. In fission yeast lacking the CTC1 ortholog, the Stn1-Ten1 complex restricts telomerase action via its sumoylation-mediated interaction with Tpz1TPP1. We identify a small ubiquitin-like modifier (SUMO)-interacting motif (SIM) in the carboxyl-terminal part of Stn1 and show that this domain is crucial for SUMO and Tpz1-SUMO interactions. Point mutations in the SIM (Stn1-226) lead to telomere elongation, impair Stn1-Ten1 recruitment to telomeres, and enhance telomerase binding, revealing that Stn1 SIM domain contributes to the inhibition of telomerase activity at chromosome ends. Our results suggest that Stn1-Ten1 promotes DNA synthesis at telomeres to limit single-strand DNA accumulation. We further demonstrate that Stn1 functions in the replication of telomeric and subtelomeric regions in a Taz1-independent manner. Genetic analysis reveals that misregulation of origin firing and/or telomerase inhibition circumvents the replication defects of the stn1-226 mutant. Together, our results show that the Stn1-Ten1 complex has a dual function at telomeres by limiting telomerase action and promoting chromosome end replication.
Collapse
Affiliation(s)
- Samah Matmati
- CRCM, CNRS, INSERM, Aix-Marseille Université, Institut Paoli-Calmettes, Equipe Labellisée Ligue, 27 Boulevard Lei Roure, Marseille, France
| | - Mélina Vaurs
- CRCM, CNRS, INSERM, Aix-Marseille Université, Institut Paoli-Calmettes, Equipe Labellisée Ligue, 27 Boulevard Lei Roure, Marseille, France
| | - José M. Escandell
- Telomere and Genome Stability Laboratory, Instituto Gulbenkian de Ciência, Oeiras, Portugal
| | - Laetitia Maestroni
- CRCM, CNRS, INSERM, Aix-Marseille Université, Institut Paoli-Calmettes, Equipe Labellisée Ligue, 27 Boulevard Lei Roure, Marseille, France
| | - Toru M. Nakamura
- Department of Biochemistry and Molecular Genetics, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Miguel G. Ferreira
- Telomere and Genome Stability Laboratory, Instituto Gulbenkian de Ciência, Oeiras, Portugal
- Institute for Research on Cancer and Aging, Nice, Faculty of Medicine, CNRS UMR7284, INSERM U1081, University of Nice Sophia Antipolis, Nice, France
| | - Vincent Géli
- CRCM, CNRS, INSERM, Aix-Marseille Université, Institut Paoli-Calmettes, Equipe Labellisée Ligue, 27 Boulevard Lei Roure, Marseille, France
| | - Stéphane Coulon
- CRCM, CNRS, INSERM, Aix-Marseille Université, Institut Paoli-Calmettes, Equipe Labellisée Ligue, 27 Boulevard Lei Roure, Marseille, France
| |
Collapse
|
70
|
Ahmed S, Kaushik M, Chaudhary S, Kukreti S. Formation of G-wires, bimolecular and tetramolecular quadruplex: Cation-induced structural polymorphs of G-rich DNA sequence of human SYTX gene. Biopolymers 2018; 109:e23115. [PMID: 29672834 DOI: 10.1002/bip.23115] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Revised: 02/07/2018] [Accepted: 02/16/2018] [Indexed: 01/18/2023]
Abstract
An exceptional property of auto-folding into a range of intra- as well as intermolecular quadruplexes by guanine-rich oligomers (GROs) of promoters, telomeres and various other genomic locations is still one of the most attractive areas of research at present times. The main reason for this attention is due to their established in vivo existence and biological relevance. Herein, the structural status of a 20-nt long G-rich sequence with two G5 stretches (SG20) is investigated using various biophysical and biochemical techniques. Bioinformatics analysis suggested the presence of a 17-nt stretch of this SG20 sequence in the intronic region of human SYTX (Synaptotagmin 10) gene. The SYTX gene helps in sensing out the Ca2+ ion, causing its intake in the pre-synaptic neuron. A range of various topologies like bimolecular, tetramolecular and guanine-wires (nano-wires) was exhibited by the studied sequence, as a function of cations (Na+ /K+ ) concentration. UV-thermal denaturation, gel electrophoresis, and circular dichroism (CD) spectroscopy showed correlations and established a cation-dependent structural switch. The G-wire formation, in the presence of K+ , may further be explored for its possible relevance in nano-biotechnological applications.
Collapse
Affiliation(s)
- Saami Ahmed
- Nucleic Acids Research Lab, Department of Chemistry, University of Delhi, Delhi, 110007, India
| | - Mahima Kaushik
- Nucleic Acids Research Lab, Department of Chemistry, University of Delhi, Delhi, 110007, India
- Cluster Innovation Centre, University of Delhi, Delhi, India
| | - Swati Chaudhary
- Nucleic Acids Research Lab, Department of Chemistry, University of Delhi, Delhi, 110007, India
| | - Shrikant Kukreti
- Nucleic Acids Research Lab, Department of Chemistry, University of Delhi, Delhi, 110007, India
| |
Collapse
|
71
|
Che T, Chen SB, Tu JL, Wang B, Wang YQ, Zhang Y, Wang J, Wang ZQ, Zhang ZP, Ou TM, Zhao Y, Tan JH, Huang ZS. Discovery of Novel Schizocommunin Derivatives as Telomeric G-Quadruplex Ligands That Trigger Telomere Dysfunction and the Deoxyribonucleic Acid (DNA) Damage Response. J Med Chem 2018; 61:3436-3453. [PMID: 29618208 DOI: 10.1021/acs.jmedchem.7b01615] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Telomeric G-quadruplex targeting and telomere maintenance interference are emerging as attractive strategies for anticancer therapies. Here, a novel molecular scaffold is explored for telomeric G-quadruplex targeting. A series of novel schizocommunin derivatives was designed and synthesized as potential telomeric G-quadruplex ligands. The interaction of telomeric G-quadruplex DNA with the derivatives was explored by biophysical assay. The cytotoxicity of the derivatives toward cancer cell lines was evaluated by the methyl thiazolyl tetrazolium (MTT) assay. Among the derivatives, compound 16 showed great stabilization ability toward telomeric G-quadruplex DNA and good cytotoxicity toward cancer cell lines. Further cellular experiments indicated that 16 could induce the formation of telomeric G-quadruplex in cells, triggering a DNA damage response at the telomere and causing telomere dysfunction. These effects ultimately provoked p53-mediated cell cycle arrest and apoptosis, and suppressed tumor growth in a mouse xenograft model. Our work provides a novel scaffold for the development of telomeric G-quadruplex ligands.
Collapse
Affiliation(s)
- Tong Che
- Guangdong Provincial Key Laboratory of New Drug Design and Evaluation, School of Pharmaceutical Sciences , Sun Yat-sen University , Guangzhou 510006 , People's Republic of China
| | - Shuo-Bin Chen
- Guangdong Provincial Key Laboratory of New Drug Design and Evaluation, School of Pharmaceutical Sciences , Sun Yat-sen University , Guangzhou 510006 , People's Republic of China
| | - Jia-Li Tu
- Guangdong Provincial Key Laboratory of New Drug Design and Evaluation, School of Pharmaceutical Sciences , Sun Yat-sen University , Guangzhou 510006 , People's Republic of China
| | - Bo Wang
- Guangdong Provincial Key Laboratory of New Drug Design and Evaluation, School of Pharmaceutical Sciences , Sun Yat-sen University , Guangzhou 510006 , People's Republic of China
| | - Yu-Qing Wang
- Guangdong Provincial Key Laboratory of New Drug Design and Evaluation, School of Pharmaceutical Sciences , Sun Yat-sen University , Guangzhou 510006 , People's Republic of China
| | - Yan Zhang
- Guangdong Provincial Key Laboratory of New Drug Design and Evaluation, School of Pharmaceutical Sciences , Sun Yat-sen University , Guangzhou 510006 , People's Republic of China
| | - Jing Wang
- Guangdong Provincial Key Laboratory of New Drug Design and Evaluation, School of Pharmaceutical Sciences , Sun Yat-sen University , Guangzhou 510006 , People's Republic of China
| | - Zeng-Qing Wang
- Guangdong Provincial Key Laboratory of New Drug Design and Evaluation, School of Pharmaceutical Sciences , Sun Yat-sen University , Guangzhou 510006 , People's Republic of China
| | - Ze-Peng Zhang
- School of Life Sciences , Sun Yat-sen University , Guangzhou 510006 , People's Republic of China
| | - Tian-Miao Ou
- Guangdong Provincial Key Laboratory of New Drug Design and Evaluation, School of Pharmaceutical Sciences , Sun Yat-sen University , Guangzhou 510006 , People's Republic of China
| | - Yong Zhao
- School of Life Sciences , Sun Yat-sen University , Guangzhou 510006 , People's Republic of China
| | - Jia-Heng Tan
- Guangdong Provincial Key Laboratory of New Drug Design and Evaluation, School of Pharmaceutical Sciences , Sun Yat-sen University , Guangzhou 510006 , People's Republic of China
| | - Zhi-Shu Huang
- Guangdong Provincial Key Laboratory of New Drug Design and Evaluation, School of Pharmaceutical Sciences , Sun Yat-sen University , Guangzhou 510006 , People's Republic of China
| |
Collapse
|
72
|
Satpathi S, Singh RK, Mukherjee A, Hazra P. Controlling anticancer drug mediated G-quadruplex formation and stabilization by a molecular container. Phys Chem Chem Phys 2018; 20:7808-7818. [PMID: 29504620 DOI: 10.1039/c8cp00325d] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Controlling of ligand mediated G-quadruplex DNA (GQ-DNA) formation and stabilization is an important and challenging aspect due to its active involvement in many biologically important processes such as DNA replication, transcription, etc. Here, we have demonstrated that topotecan (TPT), a potential anticancer drug, can instigate the formation and stabilization of GQ-DNA (H24 → GQ-DNA) in the absence of Na+/K+ ions via circular dichroism, fluorescence, NMR, UV melting and molecular dynamics (MD) simulation studies. The primary binding mode of TPT to GQ was found to be stacking at the terminal rather than binding to the groove. We have also reverted this conformational transition (GQ-DNA → H24) using a molecular container, cucurbit[7]uril (CB7), by means of the translocation of the drug (TPT) from GQ-DNA to its nanocavity. Importantly, we have carried out the detection of these conformational transitions using the fluorescence color switch of the drug, which is more direct and simple than some of the other methods that involve sophisticated and complex detection techniques.
Collapse
Affiliation(s)
- Sagar Satpathi
- Department of Chemistry, Indian Institute of Science Education and Research (IISER), Dr Homi Bhabha Road, Pashan, Pune 411008, India.
| | | | | | | |
Collapse
|
73
|
Li HL, Song J, Yong HM, Hou PF, Chen YS, Song WB, Bai J, Zheng JN. PinX1: structure, regulation and its functions in cancer. Oncotarget 2018; 7:66267-66275. [PMID: 27556185 PMCID: PMC5323232 DOI: 10.18632/oncotarget.11411] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Accepted: 08/09/2016] [Indexed: 02/07/2023] Open
Abstract
PIN2/TRF1-interacting telomerase inhibitor 1 (PinX1) is a novel cloned gene located at human chromosome 8p23, playing a vital role in maintaining telomeres length and chromosome stability. It has been demonstrated to be involved in tumor genesis and progression in most malignancies. However, some researches showed opposing molecular status of PinX1 gene and its expression patterns in several other types of tumors. The pathogenic mechanism of PinX1 expression in human malignancy is not yet clear. Moreover, emerging evidence suggest that PinX1 (especially its TID domain) might be a potential new target cancer treatment. Therefore, PinX1 may be a new potential diagnostic biomarker and therapeutic target for human cancers, and may play different roles in different human cancers. The functions and the mechanisms of PinX1 in various human cancers remain unclear, suggesting the necessity of further extensive works of its role in tumor genesis and progression.
Collapse
Affiliation(s)
- Hai-Long Li
- Jiangsu Key Laboratory of Biological Cancer Therapy, Xuzhou Medical College, Xuzhou, Jiangsu, China.,Department of Urology, The Affiliated Hospital of Xuzhou Medical College, Xuzhou, Jiangsu, China
| | - Jun Song
- Jiangsu Center for the Collaboration and Innovation of Cancer Biotherapy, Cancer Institute, Xuzhou Medical College, Xuzhou, Jiangsu, China.,Department of General Surgery, The Affiliated Hospital of Xuzhou Medical College, Xuzhou, Jiangsu, China
| | - Hong-Mei Yong
- Department of Medical Oncology, Huai'an Hospital to Xuzhou Medical College, Huai'an, Jiangsu, China
| | - Ping-Fu Hou
- Jiangsu Key Laboratory of Biological Cancer Therapy, Xuzhou Medical College, Xuzhou, Jiangsu, China.,Jiangsu Center for the Collaboration and Innovation of Cancer Biotherapy, Cancer Institute, Xuzhou Medical College, Xuzhou, Jiangsu, China
| | - Yan-Su Chen
- Jiangsu Key Laboratory of Biological Cancer Therapy, Xuzhou Medical College, Xuzhou, Jiangsu, China.,Jiangsu Center for the Collaboration and Innovation of Cancer Biotherapy, Cancer Institute, Xuzhou Medical College, Xuzhou, Jiangsu, China
| | - Wen-Bo Song
- Jiangsu Key Laboratory of Biological Cancer Therapy, Xuzhou Medical College, Xuzhou, Jiangsu, China
| | - Jin Bai
- Jiangsu Key Laboratory of Biological Cancer Therapy, Xuzhou Medical College, Xuzhou, Jiangsu, China
| | - Jun-Nian Zheng
- Jiangsu Key Laboratory of Biological Cancer Therapy, Xuzhou Medical College, Xuzhou, Jiangsu, China.,Jiangsu Center for the Collaboration and Innovation of Cancer Biotherapy, Cancer Institute, Xuzhou Medical College, Xuzhou, Jiangsu, China
| |
Collapse
|
74
|
Abstract
The implementation of quantitative approaches in telomere chromosome-oriented FISH (telomeric CO-FISH) allows the assessment of the relative efficiency of lagging versus leading strand telomere replication and thus provides information on the implicated mechanisms. Here we describe a simple method for telomere strand-specific analyses and discuss its potential applications.
Collapse
|
75
|
Feiler MO, Patel D, Li H, Meacham PJ, Watson GE, Shamlaye C, Yeates A, Broberg K, van Wijngaarden E. The association between early-life relative telomere length and childhood neurodevelopment. Neurotoxicology 2018; 65:22-27. [PMID: 29360532 DOI: 10.1016/j.neuro.2018.01.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 01/17/2018] [Accepted: 01/19/2018] [Indexed: 12/11/2022]
Abstract
PURPOSE To examine the association between telomere length and neurodevelopment in children. METHODS We examined the relationship between relative telomere length (rTL) and neurodevelopmental outcomes at 9 and 30 months, and 5 years of age in children enrolled in the Seychelles Child Development Study Nutrition Cohort 1 (NC1). Relative telomere length was measured in cord blood and in child blood at age five. Multivariable linear regression examined associations between neurodevelopmental outcomes and rTL adjusting for relevant covariates. RESULTS Mean rTL was 1.18 at birth and 0.71 at age five. Increased cord blood rTL was associated with better scores on two neurodevelopmental tests, the psychomotor developmental index (β = 4.01; 95% confidence interval (CI) = 0.17, 7.85) at age 30 months, and the Woodcock Johnson test of achievement letter-word score (β = 2.88; CI = 1.21-4.56) at age five. The Woodcock Johnson test of achievement letter-word score remained statistically significant after two outliers were excluded (β = 2.83; CI = 0.69, 4.97); the psychomotor developmental index did not (β = 3.62; CI = -1.28, 8.52). None of the neurodevelopmental outcomes at age five were associated with five-year rTL. CONCLUSION Although increased cord blood rTL was associated with better test scores for a few neurodevelopmental outcomes, this study found little consistent evidence of an association between rTL and neurodevelopment. Future studies with a larger sample size, longer follow-up, and other relevant biological markers (e.g. oxidative stress) are needed to clarify the role of rTL in neurodevelopment and its relevance as a potential surrogate measure for oxidative stress in the field of developmental neurotoxicity.
Collapse
Affiliation(s)
| | - Deven Patel
- Occupational and Environmental Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Rockville, MD, United States
| | - Huiqi Li
- Division of Occupational and Environmental Medicine, Lund University, Lund, Sweden
| | - Philip J Meacham
- University of Rochester School of Medicine and Dentistry, Rochester, NY, United States
| | - Gene E Watson
- University of Rochester School of Medicine and Dentistry, Rochester, NY, United States
| | | | | | - Karin Broberg
- Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Edwin van Wijngaarden
- University of Rochester School of Medicine and Dentistry, Rochester, NY, United States.
| |
Collapse
|
76
|
Lin CZ, Xiang GL, Zhu XH, Xiu LL, Sun JX, Zhang XY. Advances in the mechanisms of action of cancer-targeting oncolytic viruses. Oncol Lett 2018. [PMID: 29541169 DOI: 10.3892/ol.2018.7829] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Cancer virotherapy mediated by oncolytic viruses (OV), has emerged as a novel and effective strategy in cancer therapeutics. Preclinical models have demonstrated anticancer activity against numerous types of cancer. Currently, a number of recombinant viruses are in late phase clinical trials, many of which have demonstrated promising results regarding the safety and reliability of the treatments, particularly when combined with standard antineoplastic therapies. In addition to molecular-targeted therapeutics, genetic engineering of the viruses allows functional complementation to chemotherapy or radiotherapy agents. Co-administration of chemotherapy or radiotherapy is imperative for an effective treatment regime. Additionally, these approaches may be used in combination with current treatments to assist in cancer management. The near future may reveal whether this renewed interest in oncological virotherapy will result in meaningful therapeutic effects in patients. The aim of the present review was to highlight how the knowledge of oncolytic viral specificity and cytotoxicity has advanced in recent years, with a view to discuss OV in clinical application and the future directions of this field.
Collapse
Affiliation(s)
- Cun-Zhi Lin
- Department of Respiratory Medicine, The Affiliated Hospital of Qingdao University, Qingdao, Shandong 266003, P.R. China
| | - Gui-Ling Xiang
- Department of Respiratory Medicine, The Affiliated Hospital of Qingdao University, Qingdao, Shandong 266003, P.R. China
| | - Xin-Hong Zhu
- Department of General Medicine, Qingdao Municipal Hospital, Qingdao, Shandong 266071, P.R. China
| | - Lu-Lu Xiu
- Department of Respiratory Medicine, The Affiliated Hospital of Qingdao University, Qingdao, Shandong 266003, P.R. China
| | - Jia-Xing Sun
- Department of Respiratory Medicine, The Affiliated Hospital of Qingdao University, Qingdao, Shandong 266003, P.R. China
| | - Xiao-Yuan Zhang
- Department of Respiratory Medicine, The Affiliated Hospital of Qingdao University, Qingdao, Shandong 266003, P.R. China
| |
Collapse
|
77
|
Deacon K, Knox AJ. PINX1 and TERT Are Required for TNF-α-Induced Airway Smooth Muscle Chemokine Gene Expression. THE JOURNAL OF IMMUNOLOGY 2018; 200:1283-1294. [PMID: 29305433 DOI: 10.4049/jimmunol.1700414] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Accepted: 12/03/2017] [Indexed: 02/07/2023]
Abstract
Airway smooth muscle (ASM) cells contribute to asthmatic lung pathology with chemokine hypersecretion and increased ASM cell mass. With little recent progress in the development of asthma therapies, a greater understanding of lung inflammation mechanisms has become a priority. Chemokine gene expression in ASM cells is dependent upon NF-κB transcription factor activity. The telomerase/shelterin complex maintains chromosomal telomere ends during cell division. Telomerase is a possible cofactor for NF-κB activity, but its role in NF-κB activity in airway tissue inflammation is not known. In this study, we sought to address two key questions: whether telomerase is involved in inflammation in ASM cells, and whether components of the shelterin complex are also required for an inflammatory response in ASM cells. Telomerase inhibitors and telomerase small interfering RNA (siRNA) reduced TNF-α-induced chemokine expression in ASM cells. Telomerase siRNA and inhibitors reduced NF-κB activity. An siRNA screen of shelterin components identified a requirement for PIN2/TERF1 interacting-telomerase inhibitor 1 (PINX1) in chemokine gene expression. High-level PINX1 overexpression reduced NF-κB reporter activity, but low-level expression amplified NF-κB activity. Coimmunoprecipitation studies showed association of PINX1 and p65. Overexpression of the N terminus (2-252 aa) of PINX1, but not the C-terminal telomerase-inhibitor domain (253-328 aa), amplified TNF-α-induced NF-κB activity. GST pull-downs demonstrated that the N terminus of PINX1 bound more p65 than the C-terminal telomerase-inhibitor domain; these observations were confirmed in whole cells with N-terminal and C-terminal PINX1 immunoprecipitation. We conclude that telomerase and PINX1 are required for chemokine expression in ASM cells and represent significant new targets for future anti-inflammatory therapies for lung diseases, such as asthma.
Collapse
Affiliation(s)
- Karl Deacon
- Division of Respiratory Medicine, University of Nottingham, Nottingham NG5 1PB, United Kingdom
| | - Alan J Knox
- Division of Respiratory Medicine, University of Nottingham, Nottingham NG5 1PB, United Kingdom
| |
Collapse
|
78
|
Zhang WG, Jia LP, Ma J, Zhu SY, Nie SS, Song KK, Liu XM, Zhang YP, Cao D, Yang XP, Zhao DL, Xiu MJ, Lin L, Li ZX, Huang Q, Chen XZ, Chen L, Wang P, Bai XJ, Feng Z, Fu B, Hunag J, Zhang JP, Cai GY, Sun XF, Chen XM. Peripheral Blood Leukocyte Telomere Length Is Associated with Age but Not Renal Function: A Cross-Sectional Follow-Up Study. J Nutr Health Aging 2018; 22:276-281. [PMID: 29380856 DOI: 10.1007/s12603-017-0905-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
OBJECTIVES We aimed to evaluate the relationship between baseline renal function and changes in telomere length in Han Chinese. METHODS The telomere restriction fragment (TRF) length of leukocytes in the peripheral blood was measured in healthy volunteers recruited in 2014. The estimated glomerular filtration rate (eGFR) was calculated based on serum creatinine (Scr) and serum cystatin C (CysC)-eGFRcys and eGFRScr-cys through the Cockcroft-Gault formula (eGFRC-G) or the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI / eGFRCKD-EPI) equation. The correlation between telomere length changes over time and renal function was analyzed. RESULTS Leukocyte TRF lengths were negatively correlated to age (r = -0.393, p < 0.001) and serum CysC (r = -0.180, p < 0.01), while positively associated with eGFRCKD-EPI, eGFRC-G, eGFRcys, and eGFRScr-cys (r = 0.182, 0.122, 0.290, and 0.254 respectively, p < 0.01). The 3-year change of telomere length was 46 bp/years. When adjusted for age, the associations between telomere length changes and baseline, subsequent TRF lengths, and serum CysC were no longer present. No association was observed between TRF length changes and renal function. CONCLUSION The rate of telomere length changes was affected by age and baseline telomere length. The telomere length changes might be important markers for aging.
Collapse
Affiliation(s)
- W-G Zhang
- Xiangmei Chen, Department of Nephrology, Chinese PLA General Hospital, Chinese PLA Institute of Nephrology, State Key Laboratory of Kidney Diseases, National Clinical Research Center for Kidney Diseases, 28 Fuxing Road, Beijing 100853, China,
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
79
|
Abstract
The importance of telomere length to human health, aging, and cancer continues to be underappreciated. This review examines some basics of telomere biology and relates how telomere function, telomerase activity, and mutations in TERC or TERT are involved in bone marrow failure, leukemias, and other cancers. Given the challenge to obtain accurate data on telomerase activity and telomere length in specific cell types, the situation in acute myeloid leukemia (AML) remains puzzling. In most cancers, telomerase levels are increased after cells have encountered a "telomere crisis," which is typically associated with poor prognosis. Cells emerging from "telomere crisis" have defective DNA damage responses, resulting, for example, from loss of p53. Such cells often express elevated telomerase levels as a result of point mutations in the TERT promoter or amplification of the TERT gene. While telomeres in AML blasts are typically shorter than expected for normal leukocytes, most AML cells do not show evidence of having gone through a "telomere crisis." In chronic myeloid leukemia (CML), the difference between the telomere length in nonmalignant T cells and malignant blasts from the same patient was found to correlate with the remaining duration of the chronic phase. This observation supports that a mitotic clock is ticking in CML stem cells and that disease progression in CML heralds the onset of a "telomere crisis." The presence of very short telomeres in tumor cells was found to predict disease progression in chronic lymphocytic leukemia, myeloma, and various solid tumors. In view of these findings longitudinal studies of telomere length in AML appear worthwhile.
Collapse
|
80
|
Zhuang C, Huang X, Zhuang C, Luo X, Zhang X, Cai Z, Gui Y. Synthetic regulatory RNAs selectively suppress the progression of bladder cancer. JOURNAL OF EXPERIMENTAL & CLINICAL CANCER RESEARCH : CR 2017; 36:151. [PMID: 29084575 PMCID: PMC5663129 DOI: 10.1186/s13046-017-0626-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Accepted: 10/23/2017] [Indexed: 11/10/2022]
Abstract
The traditional treatment for cancer is lack of specificity and efficacy. Modular synthetic regulatory RNAs, such as inhibitive RNA (iRNA) and active RNA (aRNA), may overcome these limitations. Here, we synthesize a new iRNA to bind the upstream activating sequence (UAS) of a minimal promoter that drives expression of artificial miRNAs (amiRNAs) targeting MYC, which represses the binding interaction between UAS and GAL4 fusion protein (GAL4-VP64) in GAL4/UAS system. The aRNA driven by a tumor-specific mutant human telomerase reverse transcriptase (hTERT) promoter is created to interact with iRNA to expose UAS again in bladder cancer. Without the aRNA, mRNA and protein levels of MYC, cell growth, cell apoptosis and cell migration were no significance in two bladder cancer cell lines, T24 and 5637, and human foreskin fibroblast (HFF) cells. The aRNA significantly inhibited the expression of MYC in mRNA and protein levels, as well as the proliferation and migration of the cancer cells, but not in HFF cells. These results indicated that regulatory RNAs selectively controlled the expression of amiRNAs and ultimately suppress the progression of bladder cancer cells without affecting normal cells. Synthetic regulatory RNAs might be a selective therapeutic approach for bladder cancer.
Collapse
Affiliation(s)
- Chengle Zhuang
- Guangdong and Shenzhen Key Laboratory of Male Reproductive Medicine and Genetics, Institute of Urology, Peking University Shenzhen Hospital, Shenzhen-Peking University-the Hong Kong University of Science and Technology Medical Center, Shenzhen, 518000, People's Republic of China
| | - Xinbo Huang
- Guangdong and Shenzhen Key Laboratory of Male Reproductive Medicine and Genetics, Institute of Urology, Peking University Shenzhen Hospital, Shenzhen-Peking University-the Hong Kong University of Science and Technology Medical Center, Shenzhen, 518000, People's Republic of China
| | - Changshui Zhuang
- Guangdong and Shenzhen Key Laboratory of Male Reproductive Medicine and Genetics, Institute of Urology, Peking University Shenzhen Hospital, Shenzhen-Peking University-the Hong Kong University of Science and Technology Medical Center, Shenzhen, 518000, People's Republic of China
| | - Xiaomin Luo
- Guangdong and Shenzhen Key Laboratory of Male Reproductive Medicine and Genetics, Institute of Urology, Peking University Shenzhen Hospital, Shenzhen-Peking University-the Hong Kong University of Science and Technology Medical Center, Shenzhen, 518000, People's Republic of China
| | - Xiaowei Zhang
- The Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, 100191, People's Republic of China
| | - Zhiming Cai
- Guangdong and Shenzhen Key Laboratory of Male Reproductive Medicine and Genetics, Institute of Urology, Peking University Shenzhen Hospital, Shenzhen-Peking University-the Hong Kong University of Science and Technology Medical Center, Shenzhen, 518000, People's Republic of China
| | - Yaoting Gui
- Guangdong and Shenzhen Key Laboratory of Male Reproductive Medicine and Genetics, Institute of Urology, Peking University Shenzhen Hospital, Shenzhen-Peking University-the Hong Kong University of Science and Technology Medical Center, Shenzhen, 518000, People's Republic of China.
| |
Collapse
|
81
|
Dedeoglu B, Litjens NHR, de Weerd AE, Dor FJ, Klepper M, Reijerkerk D, Baan CC, Betjes MGH. T-Cell Composition of the Lymph Node Is Associated with the Risk for Early Rejection after Renal Transplantation. Front Immunol 2017; 8:1416. [PMID: 29163492 PMCID: PMC5663687 DOI: 10.3389/fimmu.2017.01416] [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: 08/29/2017] [Accepted: 10/12/2017] [Indexed: 01/03/2023] Open
Abstract
Background The T-cell composition within the lymph node (LN) of end-stage renal disease (ESRD) patients differs from the composition within the circulation. Activation of the alloreactive T-cell response within secondary lymphoid organs is important after organ transplantation. However, to date no data are present on LN T-cell subsets and the risk for acute rejection after kidney transplantation. Methods T cells from LNs of ESRD patients were analyzed for frequency of recent thymic emigrants, relative telomere length, expression of differentiation markers, and were related to the development of early acute rejection (EAR), occurring within 3 months after renal transplantation (RT). Furthermore, the alloreactive potential of mononuclear cells isolated from the LN and peripheral blood of 10 patients was analyzed. Measures of alloreactive potential included proliferation, cytokine production, frequencies of interferon-gamma-producing cells, and the presence of cytotoxic molecules. Results Patients with EAR were younger (p = 0.019), cytomegalovirus-seropositive (p = 0.037) and usually received dialysis prior to RT (p = 0.030). Next to this, patients with EAR showed a lower CD4:CD8 ratio (p = 0.027) within the LN. T cells from the LN were similar with regard to alloreactive capacity compared with those within the circulation. Univariate regression analysis showed that the CD4:CD8 ratio (OR: 0.67, p = 0.039), patient age (OR: 0.93, p = 0.024), and preemptive RT (OR: 0.11, p = 0.046) were associated with EAR. After a multivariate analysis, only the CD4:CD8 ratio (OR: 0.58, p = 0.019) and preemptive RT (OR:0.05, p = 0.012) were associated with EAR. Conclusion A lower CD4:CD8 ratio in the LN is associated with a higher risk for the development of rejection within 3 months after RT.
Collapse
Affiliation(s)
- Burç Dedeoglu
- Department of Internal Medicine, Section Nephrology and Transplantation, Erasmus University Medical Center, Rotterdam, Netherlands
| | - Nicolle H R Litjens
- Department of Internal Medicine, Section Nephrology and Transplantation, Erasmus University Medical Center, Rotterdam, Netherlands
| | - Annelies E de Weerd
- Department of Internal Medicine, Section Nephrology and Transplantation, Erasmus University Medical Center, Rotterdam, Netherlands
| | - Frank Jmf Dor
- Department of Surgery, Erasmus University Medical Center, Rotterdam, Netherlands
| | - Mariska Klepper
- Department of Internal Medicine, Section Nephrology and Transplantation, Erasmus University Medical Center, Rotterdam, Netherlands
| | - Derek Reijerkerk
- Department of Internal Medicine, Section Nephrology and Transplantation, Erasmus University Medical Center, Rotterdam, Netherlands
| | - Carla C Baan
- Department of Internal Medicine, Section Nephrology and Transplantation, Erasmus University Medical Center, Rotterdam, Netherlands
| | - Michiel G H Betjes
- Department of Internal Medicine, Section Nephrology and Transplantation, Erasmus University Medical Center, Rotterdam, Netherlands
| |
Collapse
|
82
|
Lim CJ, Zaug AJ, Kim HJ, Cech TR. Reconstitution of human shelterin complexes reveals unexpected stoichiometry and dual pathways to enhance telomerase processivity. Nat Commun 2017; 8:1075. [PMID: 29057866 PMCID: PMC5651854 DOI: 10.1038/s41467-017-01313-w] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Accepted: 09/07/2017] [Indexed: 01/24/2023] Open
Abstract
The human shelterin proteins associate with telomeric DNA to confer telomere protection and length regulation. They are thought to form higher-order protein complexes for their functions, but studies of shelterin proteins have been mostly limited to pairs of proteins. Here we co-express various human shelterin proteins and find that they form defined multi-subunit complexes. A complex harboring both TRF2 and POT1 has the strongest binding affinity to telomeric DNA substrates comprised of double-stranded DNA with a 3′ single-stranded extension. TRF2 interacts with TIN2 with an unexpected 2:1 stoichiometry in the context of shelterin (RAP12:TRF22:TIN21:TPP11:POT11). Tethering of TPP1 to the telomere either via TRF2–TIN2 or via POT1 gives equivalent enhancement of telomerase processivity. We also identify a peptide region from TPP1 that is both critical and sufficient for TIN2 interaction. Our findings reveal new information about the architecture of human shelterin and how it performs its functions at telomeres. The human shelterin complex protects telomere ends from being recognized as damaged DNA sites and regulates telomere length in conjunction with telomerase. Here the authors establish the stoichiometries of human shelterin complexes of various compositions and show shelterin provides dual pathways to stimulate telomerase processivity.
Collapse
Affiliation(s)
- Ci Ji Lim
- Howard Hughes Medical Institute, University of Colorado BioFrontiers Institute, Boulder, CO, 80309, USA.,Department of Chemistry & Biochemistry, University of Colorado, Boulder, CO, 80309, USA
| | - Arthur J Zaug
- Howard Hughes Medical Institute, University of Colorado BioFrontiers Institute, Boulder, CO, 80309, USA.,Department of Chemistry & Biochemistry, University of Colorado, Boulder, CO, 80309, USA
| | - Hee Jin Kim
- Howard Hughes Medical Institute, University of Colorado BioFrontiers Institute, Boulder, CO, 80309, USA.,Department of Chemistry & Biochemistry, University of Colorado, Boulder, CO, 80309, USA
| | - Thomas R Cech
- Howard Hughes Medical Institute, University of Colorado BioFrontiers Institute, Boulder, CO, 80309, USA. .,Department of Chemistry & Biochemistry, University of Colorado, Boulder, CO, 80309, USA.
| |
Collapse
|
83
|
Ameh OI, Okpechi IG, Dandara C, Kengne AP. Association Between Telomere Length, Chronic Kidney Disease, and Renal Traits: A Systematic Review. OMICS-A JOURNAL OF INTEGRATIVE BIOLOGY 2017; 21:143-155. [PMID: 28253088 DOI: 10.1089/omi.2016.0180] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Telomere length (TL) is an important biological variable that can influence a variety of disease-related complex traits as well as host-environment interactions such as drug and nutritional responses. Chronic kidney disease (CKD) is a common global health challenge especially with the currently aging world population. We conducted a PubMed database search according to the preferred reporting items for systematic reviews and meta-analysis (PRISMA) guidelines for systematic reviews. Studies in adults (18 years and above) in which TL was determined and correlated with CKD, renal traits, and function were included, while animal model studies were excluded. Nine studies comprising 7829 participants, published between 2005 and 2016, met the inclusion criteria. These included eight observational studies (six being prospective), and one clinical trial. Participants in two studies were diabetic patients with varying stages of CKD, and nondialysis chronic glomerulonephritis CKD patients in two other studies. TL measurements used polymerase chain reaction in five studies, terminal restriction fragmentation in three studies, and quantitative fluorescence in situ hybridization in one study. Short TL was independently associated with increased risk of prevalent microalbuminuria in diabetic men with CKD (p = 0.007). Among CKD patients with heterogeneous etiologies, however, there was an unadjusted lower risk (p < 0.001). Short TL was significantly associated with CKD progression among smokers (p = 0.001) and diabetic patients (p = 0.03). On the other hand, long TL was paradoxically associated with longer diagnosed duration of moderate CKD. We postulate that shortening TL might be associated with CKD prevalence/occurrence or declining kidney function, but this association is likely offset by the cellular telomere reparative process in those surviving longer with CKD. This systematic review underscores the need for future omics and human genetics research to delineate the contribution of TL to CKD, renal dysfunction, and related health outcomes. Telomeres and telomerase activity hold great promise for CKD risk stratification and personalized medicine.
Collapse
Affiliation(s)
| | - Ikechi G Okpechi
- 2 Division of Nephrology and Hypertension, Faculty of Health Sciences, University of Cape Town , Cape Town, South Africa
| | - Collet Dandara
- 3 Division of Human Genetics, Department of Pathology, Faculty of Health Sciences, Institute of Infectious Disease and Molecular Medicine, University of Cape Town , Cape Town, South Africa
| | - André-Pascal Kengne
- 4 Non-Communicable Diseases Research Unit, South African Medical Research Council, Cape Town , Cape Town, South Africa
| |
Collapse
|
84
|
Astuti Y, Wardhana A, Watkins J, Wulaningsih W. Cigarette smoking and telomere length: A systematic review of 84 studies and meta-analysis. ENVIRONMENTAL RESEARCH 2017; 158:480-489. [PMID: 28704792 PMCID: PMC5562268 DOI: 10.1016/j.envres.2017.06.038] [Citation(s) in RCA: 204] [Impact Index Per Article: 29.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Revised: 06/27/2017] [Accepted: 06/29/2017] [Indexed: 05/20/2023]
Abstract
BACKGROUND Cigarette smoking is a risk factor for ageing-related disease, but its association with biological ageing, indicated by telomere length, is unclear. METHODS We systematically reviewed evidence evaluating association between smoking status and telomere length. Searches were performed in MEDLINE (Ovid) and EMBASE (Ovid) databases, combining variation of keywords "smoking" and "telomere". Data was extracted for study characteristics and estimates for association between smoking and telomere length. Quality of studies was assessed with a risk of bias score, and publication bias was assessed with a funnel plot. I2 test was used to observe heterogeneity. Meta-analysis was carried out to compare mean difference in telomere length by smoking status, and a dose-response approach was carried out for pack-years of smoking and telomere length. A sensitivity analysis was carried out to examine sources of heterogeneity. RESULTS A total of 84 studies were included in the review, and 30 among them were included in our meta-analysis. Potential bias was addressed in half of included studies, and there was little evidence of small study bias. Telomere length was shorter among ever smokers compared to never smokers (summary standard mean difference [SMD]: -0.11 (95% CI -0.16 to -0.07)). Similarly, shorter telomere length was found among smokers compared to non-smokers, and among current smokers compared to never or former smokers. Dose-response meta-analysis suggested an inverse trend between pack-years of smoking and telomere length. However, heterogeneity among some analyses was observed. CONCLUSION Shorter telomeres among ever smokers compared to those who never smoked may imply mechanisms linking tobacco smoke exposure to ageing-related disease.
Collapse
Affiliation(s)
- Yuliana Astuti
- Department of Surgery and Cancer, Imperial College London, London, UK; Department of Obstetrics/Gynaecology, Faculty of Medicine, Universitas Gadjah Mada, Yogyakarta, Indonesia; PILAR Research and Education, Cambridge, UK
| | - Ardyan Wardhana
- PILAR Research and Education, Cambridge, UK; Department of Anaesthesiology, Faculty of Medicine, Universitas Gadjah Mada, Yogyakarta, Indonesia
| | | | - Wahyu Wulaningsih
- PILAR Research and Education, Cambridge, UK; MRC Unit for Lifelong Health and Ageing at University College London, London, UK; Division of Haematology/Oncology, Faculty of Medicine, Universitas Gadjah Mada, Yogyakarta, Indonesia.
| |
Collapse
|
85
|
Curcusone C induces telomeric DNA-damage response in cancer cells through inhibition of telomeric repeat factor 2. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2017; 1865:1372-1382. [PMID: 28870734 DOI: 10.1016/j.bbapap.2017.08.022] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Revised: 08/28/2017] [Accepted: 08/31/2017] [Indexed: 01/12/2023]
Abstract
Telomeric repeat factor 2 (known as TRF2 or TERF2) is a key component of telomere protection protein complex named as Shelterin. TRF2 helps the folding of telomere to form T-loop structure and the suppression of ATM-dependent DNA damage response activation. TRF2 has been recognized as a potentially new therapeutic target for cancer treatment. In our routine screening of small molecule libraries, we found that Curcusone C had significant effect in disrupting the binding between TRF2 and telomeric DNA, with potent antitumor activity against cancer cells. Our result showed that Curcusone C could bind with TRF2 without binding interaction with TRF1 (telomeric repeat factor 1) although these two proteins share high sequence homology, indicating that their binding conformations and biological functions in telomere could be different. Our mechanistic studies showed that Curcusone C bound with TRF2 possibly through its DNA binding site causing blockage of its interaction with telomeric DNA. Further in cellular studies indicated that the interaction of TRF2 with Curcusone C could activate DNA-damage response, inhibit tumor cell proliferation, and cause cell cycle arrest, resulting in tumor cell apoptosis. Our studies showed that Curcusone C could become a promising lead compound for further development for cancer treatment. Here, TRF2 was firstly identified as a target of Curcusone C. It is likely that the anti-cancer activity of some other terpenes and terpenoids are related with their possible effect for telomere protection proteins.
Collapse
|
86
|
Zilio N, Eifler-Olivi K, Ulrich HD. Functions of SUMO in the Maintenance of Genome Stability. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 963:51-87. [PMID: 28197906 DOI: 10.1007/978-3-319-50044-7_4] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Like in most other areas of cellular metabolism, the functions of the ubiquitin-like modifier SUMO in the maintenance of genome stability are manifold and varied. Perturbations of global sumoylation causes a wide spectrum of phenotypes associated with defects in DNA maintenance, such as hypersensitivity to DNA-damaging agents, gross chromosomal rearrangements and loss of entire chromosomes. Consistent with these observations, many key factors involved in various DNA repair pathways have been identified as SUMO substrates. However, establishing a functional connection between a given SUMO target, the cognate SUMO ligase and a relevant phenotype has remained a challenge, mainly because of the difficulties involved in identifying important modification sites and downstream effectors that specifically recognize the target in its sumoylated state. This review will give an overview over the major pathways of DNA repair and genome maintenance influenced by the SUMO system and discuss selected examples of SUMO's actions in these pathways where the biological consequences of the modification have been elucidated.
Collapse
Affiliation(s)
- Nicola Zilio
- Institute of Molecular Biology (IMB), Ackermannweg 4, D-55128, Mainz, Germany
| | | | - Helle D Ulrich
- Institute of Molecular Biology (IMB), Ackermannweg 4, D-55128, Mainz, Germany.
| |
Collapse
|
87
|
Nucleolar and coiled-body phosphoprotein 1 (NOLC1) regulates the nucleolar retention of TRF2. Cell Death Discov 2017; 3:17043. [PMID: 28875039 PMCID: PMC5582526 DOI: 10.1038/cddiscovery.2017.43] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Revised: 05/24/2017] [Accepted: 06/03/2017] [Indexed: 01/24/2023] Open
Abstract
Telomeric repeat-binding factor 2 (TRF2) was reported to localize in the nucleolus of human cells in a cell cycle-dependent manner; however, the underlying mechanism remains unclear. Here, we found that nucleolar and coiled-body phosphoprotein 1 (NOLC1) interacted with TRF2 and mediated the shuttling of TRF2 between the nucleolus and nucleus in human 293T and HepG2 cells. Ablation of NOLC1 expression increased the number of nuclear TRF2 foci and decreased the nucleolar level of TRF2. Conversely, NOLC1 overexpression promoted the nucleolar accumulation of TRF2. NOLC1 overexpression also increased the number of 53BP1 foci and induced the DNA damage response. In addition, co-expression of TRF2 rescued NOLC1 overexpression-induced cell cycle arrest and apoptosis.
Collapse
|
88
|
Daniloski Z, Smith S. Loss of Tumor Suppressor STAG2 Promotes Telomere Recombination and Extends the Replicative Lifespan of Normal Human Cells. Cancer Res 2017; 77:5530-5542. [PMID: 28819029 DOI: 10.1158/0008-5472.can-17-1260] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Revised: 07/11/2017] [Accepted: 08/08/2017] [Indexed: 01/19/2023]
Abstract
Sister chromatids are held together by cohesin, a tripartite ring with a peripheral SA1/2 subunit, where SA1 is required for telomere cohesion and SA2 for centromere cohesion. The STAG2 gene encoding SA2 is often inactivated in human cancer, but not in in a manner associated with aneuploidy. Thus, how these tumors maintain chromosomal cohesion and how STAG2 loss contributes to tumorigenesis remain open questions. Here we show that, despite a loss in centromere cohesion, sister chromatids in STAG2 mutant tumor cells maintain cohesion in mitosis at chromosome arms and telomeres. Telomere maintenance in STAG2 mutant tumor cells occurred by either telomere recombination or telomerase activation mechanisms. Notably, these cells were refractory to telomerase inhibitors, indicating recombination can provide an alternative means of telomere maintenance. STAG2 silencing in normal human cells that lack telomerase led to increased recombination at telomeres, delayed telomere shortening, and postponed senescence onset. Insofar as telomere shortening and replicative senescence prevent genomic instability and cancer by limiting the number of cell divisions, our findings suggest that extending the lifespan of normal human cells due to inactivation of STAG2 could promote tumorigenesis by extending the period during which tumor-driving mutations occur. Cancer Res; 77(20); 5530-42. ©2017 AACR.
Collapse
Affiliation(s)
- Zharko Daniloski
- Department of Pathology, Kimmel Center for Biology and Medicine at the Skirball Institute, New York University School of Medicine, New York, New York
| | - Susan Smith
- Department of Pathology, Kimmel Center for Biology and Medicine at the Skirball Institute, New York University School of Medicine, New York, New York.
| |
Collapse
|
89
|
Scott H, Kim JK, Yu C, Huang L, Qiao F, Taylor DJ. Spatial Organization and Molecular Interactions of the Schizosaccharomyces pombe Ccq1-Tpz1-Poz1 Shelterin Complex. J Mol Biol 2017; 429:2863-2872. [PMID: 28807855 DOI: 10.1016/j.jmb.2017.08.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2017] [Revised: 07/31/2017] [Accepted: 08/05/2017] [Indexed: 12/18/2022]
Abstract
The shelterin complex is a macromolecular assembly of proteins that binds to and protects telomeric DNA, which composes the ends of all linear chromosomes. Shelterin proteins prevent chromosome ends from fusing together and from eliciting erroneous induction of DNA damage response pathways. In addition, shelterin proteins play key roles in regulating the recruitment and activation of telomerase, an enzyme that extends telomeric DNA. In fission yeast, Schizosaccharomyces pombe, interactions between the shelterin proteins Ccq1, Tpz1, and Poz1 are important for regulating telomerase-mediated telomere synthesis and thus telomere length homeostasis. Here, we used electron microscopy combined with genetic labeling to define the three-dimensional arrangement of the S. pombe Ccq1-Tpz1-Poz1 (CTP) complex. Crosslinking mass spectrometry was used to identify individual residues that are in proximity to the protein-protein interfaces of the assembled CTP complex. Together, our data provide a first glimpse into the architectural design of the CTP complex and reveals unique interactions that are important in maintaining the S. pombe telomere in a non-extendible state.
Collapse
Affiliation(s)
- Harry Scott
- Department of Pharmacology, Case Western Reserve University, Cleveland, OH 44106, United States
| | - Jin-Kwang Kim
- Department of Biological Chemistry, University of California Irvine, Irvine, CA 92697, United States
| | - Clinton Yu
- Department of Physiology and Biophysics, University of California Irvine, Irvine, CA 92697, United States
| | - Lan Huang
- Department of Physiology and Biophysics, University of California Irvine, Irvine, CA 92697, United States
| | - Feng Qiao
- Department of Biological Chemistry, University of California Irvine, Irvine, CA 92697, United States.
| | - Derek J Taylor
- Department of Pharmacology, Case Western Reserve University, Cleveland, OH 44106, United States; Department of Biochemistry, Case Western Reserve University, Cleveland, OH 44106, United States.
| |
Collapse
|
90
|
Kamranvar SA, Masucci MG. Regulation of Telomere Homeostasis during Epstein-Barr virus Infection and Immortalization. Viruses 2017; 9:v9080217. [PMID: 28792435 PMCID: PMC5580474 DOI: 10.3390/v9080217] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Revised: 07/25/2017] [Accepted: 07/26/2017] [Indexed: 12/11/2022] Open
Abstract
The acquisition of unlimited proliferative potential is dependent on the activation of mechanisms for telomere maintenance, which counteracts telomere shortening and the consequent triggering of the DNA damage response, cell cycle arrest, and apoptosis. The capacity of Epstein Barr virus (EBV) to infect B-lymphocytes in vitro and transform the infected cells into autonomously proliferating immortal cell lines underlies the association of this human gamma-herpesvirus with a broad variety of lymphoid and epithelial cell malignancies. Current evidence suggests that both telomerase-dependent and -independent pathways of telomere elongation are activated in the infected cells during the early and late phases of virus-induced immortalization. Here we review the interaction of EBV with different components of the telomere maintenance machinery and the mechanisms by which the virus regulates telomere homeostasis in proliferating cells. We also discuss how these viral strategies may contribute to malignant transformation.
Collapse
Affiliation(s)
- Siamak A Kamranvar
- Department of Medical Biochemistry and Microbiology, Biomedical Center, Uppsala University, 751 23 Uppsala, Sweden.
| | - Maria G Masucci
- Department of Cell and Molecular Biology, Karolinska Institutet, 171 77 Stockholm, Sweden.
| |
Collapse
|
91
|
Telomerase Induction in HPV Infection and Oncogenesis. Viruses 2017; 9:v9070180. [PMID: 28698524 PMCID: PMC5537672 DOI: 10.3390/v9070180] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Revised: 07/05/2017] [Accepted: 07/07/2017] [Indexed: 12/11/2022] Open
Abstract
Telomerase extends the repetitive DNA at the ends of linear chromosomes, and it is normally active in stem cells. When expressed in somatic diploid cells, it can lead to cellular immortalization. Human papillomaviruses (HPVs) are associated with and high-risk for cancer activate telomerase through the catalytic subunit of telomerase, human telomerase reverse transcriptase (hTERT). The expression of hTERT is affected by both high-risk HPVs, E6 and E7. Seminal studies over the last two decades have identified the transcriptional, epigenetic, and post-transcriptional roles high-risk E6 and E7 have in telomerase induction. This review will summarize these findings during infection and highlight the importance of telomerase activation as an oncogenic pathway in HPV-associated cancer development and progression.
Collapse
|
92
|
Park JH, Lee HS, Jang MD, Han SW, Kim SK, Lee YA. Enantioselective light switch effect of Δ- and Λ-[Ru(phenanthroline)2 dipyrido[3,2-a:2′, 3′-c]phenazine]2+ bound to G-quadruplex DNA. J Biomol Struct Dyn 2017. [DOI: 10.1080/07391102.2017.1345324] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Jin Ha Park
- Department of Chemistry, Yeungnam University, Gyeongsan, Gyeong-buk, 38541, Republic of Korea
| | - Hyun Suk Lee
- Department of Chemistry, Yeungnam University, Gyeongsan, Gyeong-buk, 38541, Republic of Korea
| | - Myung Duk Jang
- Department of Materials and Engineering, Kyungwoon University, Kumi City, Gyeong-buk, 39253, Republic of Korea
| | - Sung Wook Han
- Department of Health & Biotechnology, Kyungwoon University, Kumi City, Gyeong-buk, 39253, Republic of Korea
| | - Seog K. Kim
- Department of Chemistry, Yeungnam University, Gyeongsan, Gyeong-buk, 38541, Republic of Korea
| | - Young-Ae Lee
- Department of Chemistry, Yeungnam University, Gyeongsan, Gyeong-buk, 38541, Republic of Korea
| |
Collapse
|
93
|
Gopalakrishnan V, Tan CR, Li S. Sequential phosphorylation of CST subunits by different cyclin-Cdk1 complexes orchestrate telomere replication. Cell Cycle 2017. [PMID: 28650257 DOI: 10.1080/15384101.2017.1312235] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
Abstract
Telomeres are nucleoprotein structures that cap the ends of linear chromosomes. Telomere homeostasis is central to maintaining genomic integrity. In budding yeast, Cdk1 phosphorylates the telomere-specific binding protein, Cdc13, promoting the recruitment of telomerase to telomere and thereby telomere elongation. Cdc13 is also an integral part of the CST (Cdc13-Stn1-Ten1) complex that is essential for telomere capping and counteracting telomerase-dependent telomere elongation. Therefore, telomere length homeostasis is a balance between telomerase-extendable and CST-unextendable states. In our earlier work, we showed that Cdk1 also phosphorylates Stn1 which occurs sequentially following Cdc13 phosphorylation during cell cycle progression. This stabilizes the CST complex at the telomere and results in telomerase inhibition. Hence Cdk1-dependent phosphorylations of Stn1 acts like a molecular switch that drives Cdc13 to complex with Stn1-Ten1 rather than with telomerase. However, the underlying mechanism of how a single cyclin-dependent kinase phosphorylates Cdc13 and Stn1 in temporally distinct windows is largely unclear. Here, we show that S phase cyclins are necessary for telomere maintenance. The S phase and mitotic cyclins facilitate Cdc13 and Stn1 phosphorylation respectively, to exert opposing outcomes at the telomere. Thus, our results highlight a previously unappreciated role for cyclins in telomere replication.
Collapse
Affiliation(s)
| | - Cherylin Ruiling Tan
- b Department of Biological Sciences , National University of Singapore , Singapore
| | - Shang Li
- a Program in Cancer and Stem Cell Biology , Duke-NUS Medical School , Singapore.,c Department of Physiology , Yong Loo Lin School of Medicine, National University of Singapore , Singapore
| |
Collapse
|
94
|
Zhang T, Zhang Z, Li F, Hu Q, Liu H, Tang M, Ma W, Huang J, Songyang Z, Rong Y, Zhang S, Chen BP, Zhao Y. Looping-out mechanism for resolution of replicative stress at telomeres. EMBO Rep 2017; 18:1412-1428. [PMID: 28615293 DOI: 10.15252/embr.201643866] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Revised: 04/29/2017] [Accepted: 05/08/2017] [Indexed: 01/03/2023] Open
Abstract
Repetitive DNA is prone to replication fork stalling, which can lead to genome instability. Here, we find that replication fork stalling at telomeres leads to the formation of t-circle-tails, a new extrachromosomal structure that consists of circular telomeric DNA with a single-stranded tail. Structurally, the t-circle-tail resembles cyclized leading or lagging replication intermediates that are excised from the genome by topoisomerase II-mediated cleavage. We also show that the DNA damage repair machinery NHEJ is required for the formation of t-circle-tails and for the resolution of stalled replication forks, suggesting that NHEJ, which is normally constitutively suppressed at telomeres, is activated in the context of replication stress. Inhibition of NHEJ or knockout of DNA-PKcs impairs telomere replication, leading to multiple-telomere sites (MTS) and telomere shortening. Collectively, our results support a "looping-out" mechanism, in which the stalled replication fork is cut out and cyclized to form t-circle-tails, and broken DNA is religated. The telomere loss induced by replication stress may serve as a new factor that drives replicative senescence and cell aging.
Collapse
Affiliation(s)
- Tianpeng Zhang
- Key Laboratory of Gene Engineering of the Ministry of Education, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China.,Collaborative Innovation Center of High Performance Computing, National University of Defense Technology, Changsha, China
| | - Zepeng Zhang
- Key Laboratory of Gene Engineering of the Ministry of Education, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China.,Collaborative Innovation Center of High Performance Computing, National University of Defense Technology, Changsha, China
| | - Feng Li
- Key Laboratory of Gene Engineering of the Ministry of Education, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Qian Hu
- Key Laboratory of Gene Engineering of the Ministry of Education, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China.,Collaborative Innovation Center of High Performance Computing, National University of Defense Technology, Changsha, China
| | - Haiying Liu
- Key Laboratory of Gene Engineering of the Ministry of Education, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China.,Collaborative Innovation Center of High Performance Computing, National University of Defense Technology, Changsha, China
| | - Mengfan Tang
- Key Laboratory of Gene Engineering of the Ministry of Education, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Wenbin Ma
- Key Laboratory of Gene Engineering of the Ministry of Education, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Junjiu Huang
- Key Laboratory of Gene Engineering of the Ministry of Education, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Zhou Songyang
- Key Laboratory of Gene Engineering of the Ministry of Education, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Yikang Rong
- Key Laboratory of Gene Engineering of the Ministry of Education, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Shichuan Zhang
- Department of Radiation Oncology, Sichuan Cancer Hospital, Chengdu, China
| | - Benjamin Pc Chen
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Yong Zhao
- Key Laboratory of Gene Engineering of the Ministry of Education, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China .,Collaborative Innovation Center of High Performance Computing, National University of Defense Technology, Changsha, China
| |
Collapse
|
95
|
Fang X, Hu T, Yin H, Yang J, Tang W, Hu S, Xu X. Differences in telomerase activity and the effects of AZT in aneuploid and euploid cells in colon cancer. Int J Oncol 2017. [PMID: 28627647 DOI: 10.3892/ijo.2017.4043] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Telomerase-targeted treatments for cancer have received a great deal of attention because telomerase is detected in nearly all cancer cells but is not expressed in most normal tissues. Aneuploidy refers to a chromosome number that is not a multiple of the base chromosome number and can indicate either hypo- or hyperploid chromosome numbers. Most solid tumors are aneuploid. In the present study, we sought to determine whether there are differences in telomerase activity and hTERT gene expression between aneuploid and euploid cells. Furthermore, we investigated telomerase inhibitor 3'-azido-3'-deoxythymidine (AZT)-induced cell apoptosis using the p53-Puma/Noxa/Bax pathway and cell cycle arrest using the p53-p21 pathway in both aneuploid and euploid cells. Our results demonstrate that telomerase activity and hTERT gene expression were higher in aneuploid than in euploid cells. In addition, AZT exerted time- and dose-dependent cytotoxic effects on both aneuploid and euploid cells, and aneuploid cells were more sensitive to AZT-induced cytotoxicity. In addition, both the p53-Puma/Noxa/Bax pathway and the cell cycle arrest-associated p53-p21 pathway were involved in the AZT-induced suppression of tumor cells. Importantly, aneuploid cells were more sensitive to AZT-induced cell cycle arrest (p53-p21) and DNA double-strand breaks (γ-H2AX), while euploid cells were more sensitive to AZT-induced apoptosis (p53-Puma/Bax/Noxa).
Collapse
Affiliation(s)
- Xiao Fang
- Clinical Medical College, Yangzhou University, Yangzhou, Jiangsu 225001, P.R. China
| | - Tenghui Hu
- Clinical Medical College, Yangzhou University, Yangzhou, Jiangsu 225001, P.R. China
| | - Hua Yin
- Clinical Medical College, Yangzhou University, Yangzhou, Jiangsu 225001, P.R. China
| | - Junjun Yang
- Clinical Medical College, Yangzhou University, Yangzhou, Jiangsu 225001, P.R. China
| | - Weian Tang
- Clinical Medical College, Yangzhou University, Yangzhou, Jiangsu 225001, P.R. China
| | - Siqi Hu
- Clinical Medical College, Yangzhou University, Yangzhou, Jiangsu 225001, P.R. China
| | - Xingxiang Xu
- Clinical Medical College, Yangzhou University, Yangzhou, Jiangsu 225001, P.R. China
| |
Collapse
|
96
|
Functional dissection of breast cancer risk-associated TERT promoter variants. Oncotarget 2017; 8:67203-67217. [PMID: 28978027 PMCID: PMC5620167 DOI: 10.18632/oncotarget.18226] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Accepted: 05/02/2017] [Indexed: 11/25/2022] Open
Abstract
The multi-cancer susceptibility locus at 5p15.33 includes TERT, encoding the telomerase catalytic subunit. Genome-wide association studies (GWAS) have identified six single nucleotide polymorphisms (SNPs) in the TERT promoter associated with decreased breast cancer risk, although the precise causal variants and their mechanisms of action have remained elusive. Luciferase reporter assays indicated that the protective haplotype reduced TERT promoter activity in human mammary epithelial and cancer cells in an estrogen-independent manner. Using single variant constructs, we identified rs3215401 and rs2853669 as likely functional variants. Silencing of MYC decreased TERT promoter activity but neither MYC nor ETS2 silencing conferred allele-specificity. In chromatin immunoprecipitation experiments, the ETS protein GABPA, but not ETS2 or ELF1, bound rs2853669 in an allele-specific manner in mammary epithelial cells. Investigation of open chromatin in mammoplasty samples suggested involvement of three additional variants, though not rs3215401 or rs2853669. Chromosome conformation capture revealed no interaction of the TERT promoter with regulatory elements in the locus, indicating limited local impact of candidate variants on the TERT promoter. Collectively, our functional studies of the TERT-CLPTM1L breast cancer susceptibility locus describe rs2853669 as a functional variant of this association signal among three other potentially causal variants and demonstrate the versatile mechanisms by which TERT promoter variants may affect breast cancer risk.
Collapse
|
97
|
Islam B, Stadlbauer P, Gil-Ley A, Pérez-Hernández G, Haider S, Neidle S, Bussi G, Banas P, Otyepka M, Sponer J. Exploring the Dynamics of Propeller Loops in Human Telomeric DNA Quadruplexes Using Atomistic Simulations. J Chem Theory Comput 2017; 13:2458-2480. [PMID: 28475322 PMCID: PMC5514396 DOI: 10.1021/acs.jctc.7b00226] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
![]()
We
have carried out a series of extended unbiased molecular dynamics
(MD) simulations (up to 10 μs long, ∼162 μs in
total) complemented by replica-exchange with the collective variable
tempering (RECT) approach for several human telomeric DNA G-quadruplex
(GQ) topologies with TTA propeller loops. We used different AMBER
DNA force-field variants and also processed simulations by Markov
State Model (MSM) analysis. The slow conformational transitions in
the propeller loops took place on a scale of a few μs, emphasizing
the need for long simulations in studies of GQ dynamics. The propeller
loops sampled similar ensembles for all GQ topologies and for all
force-field dihedral-potential variants. The outcomes of standard
and RECT simulations were consistent and captured similar spectrum
of loop conformations. However, the most common crystallographic loop
conformation was very unstable with all force-field versions. Although
the loss of canonical γ-trans state of the
first propeller loop nucleotide could be related to the indispensable
bsc0 α/γ dihedral potential, even supporting this particular
dihedral by a bias was insufficient to populate the experimentally
dominant loop conformation. In conclusion, while our simulations were
capable of providing a reasonable albeit not converged sampling of
the TTA propeller loop conformational space, the force-field description
still remained far from satisfactory.
Collapse
Affiliation(s)
- Barira Islam
- Institute of Biophysics, Academy of Sciences of the Czech Republic , Královopolská 135, 612 65 Brno, Czech Republic
| | - Petr Stadlbauer
- Institute of Biophysics, Academy of Sciences of the Czech Republic , Královopolská 135, 612 65 Brno, Czech Republic.,Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacký University , 17. listopadu 1192/12, 771 46 Olomouc, Czech Republic
| | - Alejandro Gil-Ley
- Scuola Internazionale Superiore di Studi Avanzati, Via Bonomea 265, 34136 Trieste, Italy
| | - Guillermo Pérez-Hernández
- Department for Mathematics and Computer Science, Freie Universität Berlin , Arnimallee 6, Berlin 14195, Germany
| | - Shozeb Haider
- UCL School of Pharmacy, 29-39 Brunswick Square, London WC1N 1AX, U.K
| | - Stephen Neidle
- UCL School of Pharmacy, 29-39 Brunswick Square, London WC1N 1AX, U.K
| | - Giovanni Bussi
- Scuola Internazionale Superiore di Studi Avanzati, Via Bonomea 265, 34136 Trieste, Italy
| | - Pavel Banas
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacký University , 17. listopadu 1192/12, 771 46 Olomouc, Czech Republic
| | - Michal Otyepka
- Institute of Biophysics, Academy of Sciences of the Czech Republic , Královopolská 135, 612 65 Brno, Czech Republic.,Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacký University , 17. listopadu 1192/12, 771 46 Olomouc, Czech Republic
| | - Jiri Sponer
- Institute of Biophysics, Academy of Sciences of the Czech Republic , Královopolská 135, 612 65 Brno, Czech Republic.,Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacký University , 17. listopadu 1192/12, 771 46 Olomouc, Czech Republic
| |
Collapse
|
98
|
Abstract
At present, no single indicator could be used as a golden index to estimate aging process. The biological age (BA), which combines several important biomarkers with mathematical modeling, has been proposed for >50 years as an aging estimation method to replace chronological age (CA). The common methods used for BA estimation include the multiple linear regression (MLR), the principal component analysis (PCA), the Hochschild's method, and the Klemera and Doubal's method (KDM). The fundamental differences in these four methods are the roles of CA and the selection criteria of aging biomarkers. In MLR and PCA, CA is treated as the selection criterion and an independent index. The Hochschild's method and KDM share a similar concept, making CA an independent variable. Previous studies have either simply constructed the BA model by one or compared the four methods together. However, reviews have yet to illustrate and compare the four methods systematically. Since the BA model is a potential estimation of aging for clinical use, such as predicting onset and prognosis of diseases, improving the elderly's living qualities, and realizing successful aging, here we summarize previous BA studies, illustrate the basic statistical steps, and thoroughly discuss the comparisons among the four common BA estimation methods.
Collapse
Affiliation(s)
- Linpei Jia
- Department of Nephrology, Second Hospital of Jilin University, Changchun, Jilin Province
- Department of Nephrology, Chinese People’s Liberation Army General Hospital, Beijing
- State Key Laboratory of Kidney Disease, Chinese People’s Liberation Army General Hospital, Beijing, People’s Republic of China
| | - Weiguang Zhang
- Department of Nephrology, Chinese People’s Liberation Army General Hospital, Beijing
- State Key Laboratory of Kidney Disease, Chinese People’s Liberation Army General Hospital, Beijing, People’s Republic of China
| | - Xiangmei Chen
- Department of Nephrology, Second Hospital of Jilin University, Changchun, Jilin Province
- Department of Nephrology, Chinese People’s Liberation Army General Hospital, Beijing
- State Key Laboratory of Kidney Disease, Chinese People’s Liberation Army General Hospital, Beijing, People’s Republic of China
| |
Collapse
|
99
|
|
100
|
Wu T, Ye M, Mao T, Lin F, Hu Y, Gan N, Shao Y. Human telomeric hybrid-2-over-hybrid-1 G-quadruplex targeting and a selective hypersaline-tolerant sensor using abasic site-engineered monomorphism. Anal Chim Acta 2017; 964:161-169. [DOI: 10.1016/j.aca.2017.01.041] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2016] [Revised: 01/13/2017] [Accepted: 01/21/2017] [Indexed: 02/02/2023]
|