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Sharma A, Kaur M, Kar A, Ranade SM, Saxena S. Ultraviolet radiation stress triggers the down-regulation of essential replication factor Mcm10. J Biol Chem 2010; 285:8352-62. [PMID: 20064936 DOI: 10.1074/jbc.m109.041129] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We report that upon UV radiation insult, mammalian cells specifically down-regulate Mcm10, a protein essential for the initiation and elongation phases of DNA replication. The levels of a majority of replication factors remain unaffected under this condition, implying that Mcm10 is a key node in the regulation of the replication machinery. High doses of ionizing gamma radiation and exposure to a combination of DNA-damaging chemicals do not decrease Mcm10 protein levels, demonstrating that Mcm10 down-regulation is triggered only by UV-specific damage. The decrease of Mcm10 protein levels is not caused by transcriptional inhibition or cleavage by apoptotic enzymes, but results from degradation by the 26 S proteasome. UV-triggered degradation of Mcm10 requires its linker or C-terminal domain. In addition, Mcm10 down-regulation is not limited to cells from a particular lineage. Therefore, our study reveals a mechanism by which mammalian cells effectively inhibit the replication machinery during stress to prevent it from drifting toward a catastrophic path of genomic instability.
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Affiliation(s)
- Aparna Sharma
- National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi 110067, India
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102
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Tjeertes JV, Miller KM, Jackson SP. Screen for DNA-damage-responsive histone modifications identifies H3K9Ac and H3K56Ac in human cells. EMBO J 2009; 28:1878-89. [PMID: 19407812 PMCID: PMC2684025 DOI: 10.1038/emboj.2009.119] [Citation(s) in RCA: 257] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2009] [Accepted: 03/26/2009] [Indexed: 01/05/2023] Open
Abstract
Recognition and repair of damaged DNA occurs within the context of chromatin. The key protein components of chromatin are histones, whose post-translational modifications control diverse chromatin functions. Here, we report our findings from a large-scale screen for DNA-damage-responsive histone modifications in human cells. We have identified specific phosphorylations and acetylations on histone H3 that decrease in response to DNA damage. Significantly, we find that DNA-damage-induced changes in H3S10p, H3S28p and H3.3S31p are a consequence of cell-cycle re-positioning rather than DNA damage per se. In contrast, H3K9Ac and H3K56Ac, a mark previously uncharacterized in human cells, are rapidly and reversibly reduced in response to DNA damage. Finally, we show that the histone acetyl-transferase GCN5/KAT2A acetylates H3K56 in vitro and in vivo. Collectively, our data indicate that though most histone modifications do not change appreciably after genotoxic stress, H3K9Ac and H3K56Ac are reduced in response to DNA damage in human cells.
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Affiliation(s)
- Jorrit V Tjeertes
- The Gurdon Institute, University of Cambridge, Cambridge, UK
- These authors contributed equally to this work
| | - Kyle M Miller
- The Gurdon Institute, University of Cambridge, Cambridge, UK
- These authors contributed equally to this work
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103
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Glycine regulates proliferation and differentiation of salivary-gland-derived progenitor cells. Cell Tissue Res 2009; 336:203-12. [DOI: 10.1007/s00441-009-0767-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2008] [Accepted: 01/13/2009] [Indexed: 12/26/2022]
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104
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Stubbert LJ, Smith JM, Hamill JD, Arcand TL, McKay BC. The anti-apoptotic role for p53 following exposure to ultraviolet light does not involve DDB2. Mutat Res 2009; 663:69-76. [PMID: 19428372 DOI: 10.1016/j.mrfmmm.2009.01.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2008] [Revised: 12/24/2008] [Accepted: 01/27/2009] [Indexed: 01/26/2023]
Abstract
The p53 tumour suppressor is a transcription factor that can either activate or repress the expression of specific genes in response to cellular stresses such as exposure to ultraviolet light. The p53 protein can exert both pro- and anti-apoptotic effects depending on cellular context. In primary human fibroblasts, p53 protects cells from UV-induced apoptosis at moderate doses but this is greatly affected by the nucleotide excision repair (NER) capacity of the cells. The damage-specific DNA binding protein 2 (DDB2) is involved in NER and is associated with xeroderma pigmentosum subgroup E (XP-E). Importantly, DDB2 is also positively regulated by the p53 protein. To study the potential interplay between DDB2 and p53 in determining the apoptotic response of primary fibroblasts exposed to UV light, the expression of these proteins was manipulated in primary normal and XP-E fibroblast strains using human papillomavirus E6 protein (HPV-E6), RNA interference and recombinant adenoviruses expressing either p53 or DDB2. Normal and XP-E fibroblast strains were equally sensitive to UV-induced apoptosis over a broad range of doses and disruption of p53 in these strains using HPV-E6 or RNA interference led to a similar increase in apoptosis following exposure to UV light. In contrast, forced expression of p53 or DDB2 did not affect UV-induced apoptosis greatly in these normal or XP-E fibroblast strains. Collectively, these results indicate that p53 is primarily protective against UV-induced apoptosis in primary human fibroblasts and this activity of p53 does not require DDB2.
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Affiliation(s)
- L J Stubbert
- Cancer Therapeutics Program, Ottawa Health Research Institute, Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada
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105
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Cheong JK, Gunaratnam L, Zang ZJ, Yang CM, Sun X, Nasr SL, Sim KG, Peh BK, Rashid SBA, Bonventre JV, Salto-Tellez M, Hsu SI. TRIP-Br2 promotes oncogenesis in nude mice and is frequently overexpressed in multiple human tumors. J Transl Med 2009; 7:8. [PMID: 19152710 PMCID: PMC2671481 DOI: 10.1186/1479-5876-7-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2008] [Accepted: 01/20/2009] [Indexed: 01/09/2023] Open
Abstract
Background Members of the TRIP-Br/SERTAD family of mammalian transcriptional coregulators have recently been implicated in E2F-mediated cell cycle progression and tumorigenesis. We, herein, focus on the detailed functional characterization of the least understood member of the TRIP-Br/SERTAD protein family, TRIP-Br2 (SERTAD2). Methods Oncogenic potential of TRIP-Br2 was demonstrated by (1) inoculation of NIH3T3 fibroblasts, which were engineered to stably overexpress ectopic TRIP-Br2, into athymic nude mice for tumor induction and (2) comprehensive immunohistochemical high-throughput screening of TRIP-Br2 protein expression in multiple human tumor cell lines and human tumor tissue microarrays (TMAs). Clinicopathologic analysis was conducted to assess the potential of TRIP-Br2 as a novel prognostic marker of human cancer. RNA interference of TRIP-Br2 expression in HCT-116 colorectal carcinoma cells was performed to determine the potential of TRIP-Br2 as a novel chemotherapeutic drug target. Results Overexpression of TRIP-Br2 is sufficient to transform murine fibroblasts and promotes tumorigenesis in nude mice. The transformed phenotype is characterized by deregulation of the E2F/DP-transcriptional pathway through upregulation of the key E2F-responsive genes CYCLIN E, CYCLIN A2, CDC6 and DHFR. TRIP-Br2 is frequently overexpressed in both cancer cell lines and multiple human tumors. Clinicopathologic correlation indicates that overexpression of TRIP-Br2 in hepatocellular carcinoma is associated with a worse clinical outcome by Kaplan-Meier survival analysis. Small interfering RNA-mediated (siRNA) knockdown of TRIP-Br2 was sufficient to inhibit cell-autonomous growth of HCT-116 cells in vitro. Conclusion This study identifies TRIP-Br2 as a bona-fide protooncogene and supports the potential for TRIP-Br2 as a novel prognostic marker and a chemotherapeutic drug target in human cancer.
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Affiliation(s)
- Jit Kong Cheong
- Renal Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA.
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Ceruti JM, Scassa ME, Marazita MC, Carcagno AC, Sirkin PF, Cánepa ET. Transcriptional upregulation of p19INK4d upon diverse genotoxic stress is critical for optimal DNA damage response. Int J Biochem Cell Biol 2008; 41:1344-53. [PMID: 19130897 DOI: 10.1016/j.biocel.2008.12.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2008] [Revised: 11/04/2008] [Accepted: 12/08/2008] [Indexed: 12/25/2022]
Abstract
p19INK4d promotes survival of several cell lines after UV irradiation due to enhanced DNA repair, independently of CDK4 inhibition. To further understand the action of p19INK4d in the cellular response to DNA damage, we aimed to elucidate whether this novel regulator plays a role only in mechanisms triggered by UV or participates in diverse mechanisms initiated by different genotoxics. We found that p19INK4d is induced in cells injured with cisplatin or beta-amyloid peptide as robustly as with UV. The mentioned genotoxics transcriptionally activate p19INK4d expression as demonstrated by run-on assay without influencing its mRNA stability and with partial requirement of protein synthesis. It is not currently known whether DNA damage-inducible genes are turned on by the DNA damage itself or by the consequences of that damage. Experiments carried out in cells transfected with distinct damaged DNA structures revealed that the damage itself is not responsible for the observed up-regulation. It is also not known whether the increased expression of DNA-damage-inducible genes is related to immediate protective responses such as DNA repair or to more delayed responses such as cell cycle arrest or apoptosis. We found that ectopic expression of p19INK4d improves DNA repair ability and protects neuroblastoma cells from apoptosis caused by cisplatin or beta-amyloid peptide. Using clonal cell lines where p19INK4d levels can be modified at will, we show that p19INK4d expression correlates with increased survival and clonogenicity. The results presented here, prompted us to suggest that p19INK4d displays an important role in an early stage of cellular DNA damage response.
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Affiliation(s)
- Julieta M Ceruti
- Laboratorio de Biología Molecular, Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria Pabellón II Piso 4, 1428 Buenos Aires, Argentina.
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107
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Shant J, Cheng K, Marasa BS, Wang JY, Raufman JP. Akt-dependent NF-kappaB activation is required for bile acids to rescue colon cancer cells from stress-induced apoptosis. Exp Cell Res 2008; 315:432-50. [PMID: 19056378 DOI: 10.1016/j.yexcr.2008.11.003] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2008] [Revised: 10/02/2008] [Accepted: 11/06/2008] [Indexed: 12/11/2022]
Abstract
Conjugated secondary bile acids promote human colon cancer cell proliferation by activating EGF receptors (EGFR). We hypothesized that bile acid-induced EGFR activation also mediates cell survival by downstream Akt-regulated activation of NF-kappaB. Deoxycholyltaurine (DCT) treatment attenuated TNF-alpha-induced colon cancer cell apoptosis, and stimulated rapid and sustained NF-kappaB nuclear translocation and transcriptional activity (detected by NF-kappaB binding to an oligonucleotide consensus sequence and by activation of luciferase reporter gene constructs). Both DCT-induced NF-kappaB nuclear translocation and attenuation of TNF-alpha-stimulated apoptosis were dependent on EGFR activation. Inhibitors of nuclear translocation, proteosome activity, and IkappaBalpha kinase attenuated NF-kappaB transcriptional activity. Cell transfection with adenoviral vectors encoding a non-degradable IkappaBalpha 'super-repressor' blocked the actions of DCT on both NF-kappaB activation and TNF-alpha-induced apoptosis. Likewise, transfection with mutant akt and treatment with a chemical inhibitor of Akt attenuated effects of DCT on NF-kappaB transcriptional activity and TNF-alpha-induced apoptosis. Chemical inhibitors of Akt and NF-kappaB activation also attenuated DCT-induced rescue of H508 cells from ultraviolet radiation-induced apoptosis. Collectively, these observations indicate that, downstream of EGFR, bile acid-induced colon cancer cell survival is mediated by Akt-dependent NF-kappaB activation. These findings provide a mechanism whereby bile acids increase resistance of colon cancer to chemotherapy and radiation.
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Affiliation(s)
- Jasleen Shant
- Division of Gastroenterology and Hepatology, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA
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108
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Woods Ignatoski KM, Grewal NK, Markwart SM, Vellaichamy A, Chinnaiyan AM, Yeung K, Ray ME, Keller ET. Loss of Raf kinase inhibitory protein induces radioresistance in prostate cancer. Int J Radiat Oncol Biol Phys 2008; 72:153-60. [PMID: 18722266 DOI: 10.1016/j.ijrobp.2008.04.072] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2008] [Revised: 04/10/2008] [Accepted: 04/11/2008] [Indexed: 12/22/2022]
Abstract
PURPOSE External beam radiotherapy (RT) is often used in an attempt to cure localized prostate cancer (PCa), but it is only palliative against disseminated disease. Raf kinase inhibitory protein (RKIP) is a metastasis suppressor whose expression is reduced in approximately 50% of localized PCa tissues and is absent in metastases. Chemotherapeutic agents have been shown to induce tumor apoptosis through induction of RKIP expression. Our goal was to test whether RT similarly induces apoptosis through induction of RKIP expression. METHODS AND MATERIALS The C4-2B PCa cell line was engineered to overexpress or underexpress RKIP. The engineered cells were tested for apoptosis in cell culture and tumor regression in mice after RT. RESULTS RT induced both RKIP expression and apoptosis of PCa cells. Overexpression of RKIP sensitized PCa cells to radiation-induced apoptosis. In contrast, short-hairpin targeting of RKIP, so that RT could not induce RKIP expression, protected cells from radiation-induced apoptosis. In a murine model, knockdown of RKIP in PCa cells diminished radiation-induced apoptosis. Molecular concept mapping of genes altered on manipulation of RKIP expression revealed an inverse correlation with the concept of genes altered by RT. CONCLUSION The data presented in this report indicate that the loss of RKIP, as seen in primary PCa tumors and metastases, confers protection against radiation-induced apoptosis. Therefore, it is conceivable that the loss of RKIP confers a growth advantage on PCa cells at distant sites, because the loss of RKIP would decrease apoptosis, favoring proliferation.
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The absence of Ser389 phosphorylation in p53 affects the basal gene expression level of many p53-dependent genes and alters the biphasic response to UV exposure in mouse embryonic fibroblasts. Mol Cell Biol 2008; 28:1974-87. [PMID: 18195040 DOI: 10.1128/mcb.01610-07] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Phosphorylation is important in p53-mediated DNA damage responses. After UV irradiation, p53 is phosphorylated specifically at murine residue Ser389. Phosphorylation mutant p53.S389A cells and mice show reduced apoptosis and compromised tumor suppression after UV irradiation. We investigated the underlying cellular processes by time-series analysis of UV-induced gene expression responses in wild-type, p53.S389A, and p53(-/-) mouse embryonic fibroblasts. The absence of p53.S389 phosphorylation already causes small endogenous gene expression changes for 2,253, mostly p53-dependent, genes. These genes showed basal gene expression levels intermediate to the wild type and p53(-/-), possibly to readjust the p53 network. Overall, the p53.S389A mutation lifts p53-dependent gene repression to a level similar to that of p53(-/-) but has lesser effect on p53-dependently induced genes. In the wild type, the response of 6,058 genes to UV irradiation was strictly biphasic. The early stress response, from 0 to 3 h, results in the activation of processes to prevent the accumulation of DNA damage in cells, whereas the late response, from 12 to 24 h, relates more to reentering the cell cycle. Although the p53.S389A UV gene response was only subtly changed, many cellular processes were significantly affected. The early response was affected the most, and many cellular processes were phase-specifically lost, gained, or altered, e.g., induction of apoptosis, cell division, and DNA repair, respectively. Altogether, p53.S389 phosphorylation seems essential for many p53 target genes and p53-dependent processes.
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110
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Shimada M, Niida H, Zineldeen DH, Tagami H, Tanaka M, Saito H, Nakanishi M. Chk1 Is a Histone H3 Threonine 11 Kinase that Regulates DNA Damage-Induced Transcriptional Repression. Cell 2008; 132:221-32. [DOI: 10.1016/j.cell.2007.12.013] [Citation(s) in RCA: 199] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2007] [Revised: 10/17/2007] [Accepted: 12/05/2007] [Indexed: 11/29/2022]
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111
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Latonen L, Järvinen PM, Laiho M. Cytoskeleton-interacting LIM-domain protein CRP1 suppresses cell proliferation and protects from stress-induced cell death. Exp Cell Res 2007; 314:738-47. [PMID: 18177859 DOI: 10.1016/j.yexcr.2007.11.024] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2007] [Revised: 10/25/2007] [Accepted: 11/27/2007] [Indexed: 11/19/2022]
Abstract
Members of the cysteine-rich protein (CRP) family are actin cytoskeleton-interacting LIM-domain proteins known to act in muscle cell differentiation. We have earlier found that CRP1, a founding member of this family, is transcriptionally induced by UV radiation in human diploid fibroblasts [M. Gentile, L. Latonen, M. Laiho, Cell cycle arrest and apoptosis provoked by UV radiation-induced DNA damage are transcriptionally highly divergent responses, Nucleic Acids Res. 31 (2003) 4779-4790]. Here we show that CRP1 is induced by growth-inhibitory signals, such as increased cellular density, and cytotoxic stress induced by UV radiation or staurosporine. We found that high levels of CRP1 correlate with differentiation-associated morphology towards the myofibroblast lineage and that expression of ectopic CRP1 suppresses cell proliferation. Following UV- and staurosporine-induced stresses, expression of CRP1 provides a survival advantage evidenced by decreased cellular death and increased cellular metabolic activity and attachment. Our studies identify that CRP1 is a novel stress response factor, and provide evidence for its growth-inhibitory and cytoprotective functions.
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Affiliation(s)
- Leena Latonen
- Molecular Cancer Biology Program, University of Helsinki, PO Box 63, FIN-00014 Helsinki, Finland
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112
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Ito S, Kita K, Zhal L, Wano C, Suzuki T, Yamaura A, Suzuki N. Involvement of Human Small Fragment Nuclease in the Resistance of Human Cells to UV-C-induced Cell Death¶. Photochem Photobiol 2007. [DOI: 10.1111/j.1751-1097.2004.tb00084.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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113
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Han J, Goldstein LA, Hou W, Rabinowich H. Functional linkage between NOXA and Bim in mitochondrial apoptotic events. J Biol Chem 2007; 282:16223-31. [PMID: 17374615 DOI: 10.1074/jbc.m611186200] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
NOXA is a BH3-only protein whose expression is induced by certain p53-depenent or independent apoptotic stimuli. Both NOXA and Bim are avid binders of Mcl-1, but a functional linkage between these BH3-only proteins has not yet been reported. In this study, we demonstrate that Mcl-1 binding of endogenously induced NOXA interferes with the ability of Mcl-1 to efficiently sequester endogenous Bim, as Bim is displaced from its complex with Mcl-1. Induced NOXA significantly enhances the UV sensitivity of cells, and the ensuing mitochondrial depolarization is entirely abrogated by Bim knockdown. These results demonstrate a Mcl-1-mediated cross-talk between endogenous NOXA and Bim that occurs upstream of the Bak/Bax-dependent execution of UV-induced mitochondrial depolarization. The current findings demonstrate that the mitochondrial response to an induced expression of NOXA is executed by endogenous Bim and suggest a plausible mechanism for the observed NOXA-Bim linkage.
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Affiliation(s)
- Jie Han
- Department of Pathology, University of Pittsburgh School of Medicine, PA 15213, USA
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114
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Di Camillo B, Toffolo G, Nair SK, Greenlund LJ, Cobelli C. Significance analysis of microarray transcript levels in time series experiments. BMC Bioinformatics 2007; 8 Suppl 1:S10. [PMID: 17430554 PMCID: PMC1885839 DOI: 10.1186/1471-2105-8-s1-s10] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
Background Microarray time series studies are essential to understand the dynamics of molecular events. In order to limit the analysis to those genes that change expression over time, a first necessary step is to select differentially expressed transcripts. A variety of methods have been proposed to this purpose; however, these methods are seldom applicable in practice since they require a large number of replicates, often available only for a limited number of samples. In this data-poor context, we evaluate the performance of three selection methods, using synthetic data, over a range of experimental conditions. Application to real data is also discussed. Results Three methods are considered, to assess differentially expressed genes in data-poor conditions. Method 1 uses a threshold on individual samples based on a model of the experimental error. Method 2 calculates the area of the region bounded by the time series expression profiles, and considers the gene differentially expressed if the area exceeds a threshold based on a model of the experimental error. These two methods are compared to Method 3, recently proposed in the literature, which exploits splines fit to compare time series profiles. Application of the three methods to synthetic data indicates that Method 2 outperforms the other two both in Precision and Recall when short time series are analyzed, while Method 3 outperforms the other two for long time series. Conclusion These results help to address the choice of the algorithm to be used in data-poor time series expression study, depending on the length of the time series.
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Affiliation(s)
- Barbara Di Camillo
- Information Engineering Department, University of Padova, 35131 Padova, Italy
| | - Gianna Toffolo
- Information Engineering Department, University of Padova, 35131 Padova, Italy
| | | | - Laura J Greenlund
- Endocrinology Division, Mayo Clinic, Rochester, Minnesota 55905, USA
| | - Claudio Cobelli
- Information Engineering Department, University of Padova, 35131 Padova, Italy
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Yamashiro K, Myokai F, Hiratsuka K, Yamamoto T, Senoo K, Arai H, Nishimura F, Abiko Y, Takashiba S. Oligonucleotide array analysis of cyclic tension-responsive genes in human periodontal ligament fibroblasts. Int J Biochem Cell Biol 2007; 39:910-21. [PMID: 17409011 DOI: 10.1016/j.biocel.2007.01.015] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2006] [Revised: 12/07/2006] [Accepted: 01/02/2007] [Indexed: 11/16/2022]
Abstract
Mechanical stress results in differential gene expression that is critical to convert the stimulus into biochemical signals. Under physiological stress such as occlusal force, human periodontal ligament fibroblasts (HPLF) are associated with homeostasis of periodontal tissues however the changes in response to mechanotransduction remain uncharacterized. We hypothesized that cyclic tension-responsive (CT) genes may be used to identify a set of fundamental pathways of mechanotransduction. Our goal was to catalogue CT genes in cultured HPLF. HPLF were subjected to cyclic tension up to 16h, and total RNA was isolated from both tension-loaded and static HPLF. The oligonucleotide arrays analysis revealed significant changes of mRNA accumulation for 122 CT genes, and their kinetics were assigned by the K-means clustering methods. Ingenuity Pathway Analysis was completed for HPLF mechanotransduction using 50 CT genes. This analysis revealed that cyclic tension immediately down-regulated all nuclear transcription factors except v-fos FBJ murine osteosarcoma viral oncogene homolog (FOS) reacting as an early responsive gene. In turn, transcription factors such as tumor protein p53 binding protein 2 (TP53BP2), and extra-nuclear molecules such as adrenergic receptor beta2 (ADRB2) were up-regulated after 1-2h, which may result in fundamental HPLF functions to adapt to cyclic tension. Subsequent inhibition assays using Y27632, a pharmacologic inhibitor of Rho-associated kinase (ROCK), suggested that HPLF has both ROCK-dependent and ROCK-independent CT genes. Mechanical stress was found to effect the expression of numerous genes, in particular, expression of an early responsive gene; FOS initiates alteration of HPLF behaviors to control homeostasis of the periodontal ligament.
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Affiliation(s)
- Keisuke Yamashiro
- Department of Pathophysiology-Periodontal Science, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Okayama 700-8525, Japan
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116
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Roscic A, Möller A, Calzado MA, Renner F, Wimmer VC, Gresko E, Lüdi KS, Schmitz ML. Phosphorylation-dependent control of Pc2 SUMO E3 ligase activity by its substrate protein HIPK2. Mol Cell 2006; 24:77-89. [PMID: 17018294 DOI: 10.1016/j.molcel.2006.08.004] [Citation(s) in RCA: 102] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2006] [Revised: 07/04/2006] [Accepted: 08/04/2006] [Indexed: 11/24/2022]
Abstract
Sumoylation serves to control key cellular functions, but the regulation of SUMO E3 ligase activity is largely unknown. Here we show that the polycomb group protein Pc2 binds to and colocalizes with homeodomain interacting protein kinase 2 (HIPK2) and serves as a SUMO E3 ligase for this kinase. DNA damage-induced HIPK2 directly phosphorylates Pc2 at multiple sites, which in turn controls Pc2 sumoylation and intranuclear localization. Inducible phosphorylation of Pc2 at threonine 495 is required for its ability to increase HIPK2 sumoylation in response to DNA damage, thereby establishing an autoregulatory feedback loop between a SUMO substrate and its cognate E3 ligase. Sumoylation enhances the ability of HIPK2 to mediate transcriptional repression, thus providing a mechanistic link for DNA damage-induced transcriptional silencing.
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Affiliation(s)
- Ana Roscic
- Institute of Biochemistry, Medical Faculty, Friedrichstrasse 24, Justus-Liebig-University, D-35392 Giessen, Germany
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Hoffmann D, Wildner O. Efficient generation of double heterologous promoter controlled oncolytic adenovirus vectors by a single homologous recombination step in Escherichia coli. BMC Biotechnol 2006; 6:36. [PMID: 16887042 PMCID: PMC1557486 DOI: 10.1186/1472-6750-6-36] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2006] [Accepted: 08/03/2006] [Indexed: 12/05/2022] Open
Abstract
Background Oncolytic adenoviruses are promising agents for the multimodal treatment of cancer. However, tumor-selectivity is crucial for their applicability in patients. Recent studies by several groups demonstrated that oncolytic adenoviruses with tumor-/tissue-specific expression of the E1 and E4 genes, which are pivotal for adenoviral replication, have a specificity profile that is superior to viruses that solely target the expression of E1 or E4 genes. Presently the E1 and E4 regions are modified in a time consuming sequential fashion. Results Based on the widely used adenoviral cloning system AdEasy we generated a novel transfer vector that allows efficient and rapid generation of conditionally replication-competent adenovirus type 5 based vectors with the viral E1 and E4 genes under the transcriptional control of heterologous promoters. For insertion of the promoters of interest our transfer vector has two unique multiple cloning sites. Additionally, our shuttle plasmid allows encoding of a transgene within the E1A transcription unit. The modifications, including E1 mutations, are introduced into the adenoviral genome by a single homologous recombination step in Escherichia coli. Subsequently infectious viruses are rescued from plasmids. As a proof-of-concept we generated two conditionally replication-competent adenoviruses Ad.Ki•COX and Ad.COX•Ki with the promoters of the Ki-67 protein and the cyclooxygenase-2 (COX-2) driving E1 and E4 and vice versa. Conclusion We demonstrated with our cloning system efficient generation of double heterologous promoter controlled oncolytic adenoviral vectors by a single homologous recombination step in bacteria. The generated viruses showed preferential replication in tumor cells and in a subcutaneous HT-29 colon cancer xenograft model the viruses demonstrated significant oncolytic activity comparable with dl327.
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Affiliation(s)
- Dennis Hoffmann
- Ruhr-University Bochum, Institute of Microbiology and Hygiene, Department of Molecular and Medical Virology, Bldg. MA, Rm. 6/40, D-44801 Bochum, Germany
| | - Oliver Wildner
- Ruhr-University Bochum, Institute of Microbiology and Hygiene, Department of Molecular and Medical Virology, Bldg. MA, Rm. 6/40, D-44801 Bochum, Germany
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118
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Latonen L, Laiho M. Cellular UV damage responses--functions of tumor suppressor p53. Biochim Biophys Acta Rev Cancer 2005; 1755:71-89. [PMID: 15921859 DOI: 10.1016/j.bbcan.2005.04.003] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2004] [Revised: 04/07/2005] [Accepted: 04/21/2005] [Indexed: 02/06/2023]
Abstract
DNA damage, provoked by ultraviolet (UV) radiation, evokes a cellular damage response composed of activation of stress signaling and DNA checkpoint functions. These are translated to responses of replicative arrest, damage repair, and apoptosis aimed at cellular recovery from the damage. p53 tumor suppressor is a central stress response protein, activated by multiple endogenous and environmental insults, including UV radiation. The significance of p53 in the DNA damage responses has frequently been reviewed in the context of ionizing radiation or other double strand break (DSB)-inducing agents. Despite partly similar patterns, the molecular events following UV radiation are, however, distinct from the responses induced by DSBs and are profoundly coupled with transcriptional stress. These are illustrated, e.g., by the UV damage-specific translocations of Mdm2, promyelocytic leukemia protein, and nucleophosmin and their interactions with p53. In this review, we discuss UV damage-provoked cellular responses and the functions of p53 in damage recovery and cell death.
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Affiliation(s)
- Leena Latonen
- Molecular and Cancer Biology Program and Haartman Institute, University of Helsinki, PO Box 63, FIN-00014 Helsinki, Finland
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119
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da Costa RMA, Riou L, Paquola A, Menck CFM, Sarasin A. Transcriptional profiles of unirradiated or UV-irradiated human cells expressing either the cancer-prone XPB/CS allele or the noncancer-prone XPB/TTD allele. Oncogene 2004; 24:1359-74. [PMID: 15608684 DOI: 10.1038/sj.onc.1208288] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Xeroderma pigmentosum (XP) and trichothiodystrophy (TTD) syndromes are characterized by deficiency in nucleotide excision repair pathway, but with distinguished clinical manifestations. While XP patients exhibit a high frequency of skin cancer, TTD patients are not cancer prone. The relation between lack of DNA repair and their clinical manifestations was investigated through analysis of the transcriptional profile of 12,600 transcripts in two isogenic cell lines with different capabilities of DNA repair. These cell lines result from a stable transfection of the XPB-TTD allele into XP complementation group B fibroblasts, from an XP patient who also have clinical abnormalities corresponding to Cockayne's syndrome (CS). The microarray assays performed under normal growth conditions showed the expression of distinct groups of genes in each cell line. The UVC-transcription modulation of these cells revealed the changes in 869 transcripts. Some of these transcripts had similar modulation pattern in both cells, although with eventually different time patterns for induction or repression. However, some different 'UVC signature' for each cell line was also found, that is, transcripts that were specifically UV regulated depending on the DNA repair status of the cell. These results provide a detailed portrait of expression profiles that may potentially unravel the causes of the different phenotypes of XP/CS and TTD patients.
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120
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McKay BC, Stubbert LJ, Fowler CC, Smith JM, Cardamore RA, Spronck JC. Regulation of ultraviolet light-induced gene expression by gene size. Proc Natl Acad Sci U S A 2004; 101:6582-6. [PMID: 15087501 PMCID: PMC404088 DOI: 10.1073/pnas.0308181101] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
UV light induces the expression of a wide variety of genes. At present, it is unclear how cells sense the extent of DNA damage and alter the expression of UV-induced genes appropriately. UV light induces DNA damage that blocks transcription, and the probability that a gene sustains transcription-blocking DNA damage is proportional to locus size and dose of UV light. Using colon carcinoma cells that express a temperature-sensitive variant of p53 and undergo p53-dependent apoptosis after UV irradiation, we found that the number of p53-induced genes identified by oligonucleotide microarray analysis decreased in a UV dose-dependent manner. This was associated with a statistically significant shift in the spectrum of p53-induced genes toward compact genes with fewer and smaller introns. Genes encoding proapoptotic proteins involved in the initiation of the mitochondrial apoptotic cascade were prominent among the compact p53 target genes, whereas genes encoding negative regulators of p53 and the mitochondrial apoptotic pathway were significantly larger. We propose that the shift in spectrum of UV-responsive gene expression caused by passive effects of UV lesions on transcription acts as a molecular dosimeter, ensuring the elimination of cells sustaining irreparable transcription-blocking DNA damage.
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Affiliation(s)
- Bruce C McKay
- Centre for Cancer Therapeutics, Ottawa Regional Cancer Centre, Department of Radiology, University of Ottawa, 503 Smyth Road, Ottawa, ON, Canada K1C 5T5.
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121
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Ito S, Kita K, Zhai L, Wano C, Suzuki T, Yamaura A, Suzuki N. Involvement of Human Small Fragment Nuclease in the Resistance of Human Cells to UV-C–induced Cell Death¶. Photochem Photobiol 2004. [DOI: 10.1562/2004-01-21-ra-051.1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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