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Landman N, Hulsman D, Badhai J, Kopparam J, Puppe J, Pandey GK, van Lohuizen M. Combination of EZH2 and ATM inhibition in BAP1-deficient mesothelioma. Br J Cancer 2024; 130:1855-1865. [PMID: 38519707 PMCID: PMC11130181 DOI: 10.1038/s41416-024-02661-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Revised: 03/11/2024] [Accepted: 03/13/2024] [Indexed: 03/25/2024] Open
Abstract
BACKGROUND More than half of mesothelioma tumours show alterations in the tumour suppressor gene BAP1. BAP1-deficient mesothelioma is shown to be sensitive to EZH2 inhibition in preclinical settings but only showed modest efficacy in clinical trial. Adding a second inhibitor could potentially elevate EZH2i treatment efficacy while preventing acquired resistance at the same time. METHODS A focused drug synergy screen consisting of 20 drugs was performed by combining EZH2 inhibition with a panel of anti-cancer compounds in mesothelioma cell lines. The compounds used are under preclinical investigation or already used in the clinic. The synergistic potential of the combinations was assessed by using the Bliss model. To validate our findings, in vivo xenograft experiments were performed. RESULTS Combining EZH2i with ATMi was found to have synergistic potential against BAP1-deficient mesothelioma in our drug screen, which was validated in clonogenicity assays. Tumour growth inhibition potential was significantly increased in BAP1-deficient xenografts. In addition, we observe lower ATM levels upon depletion of BAP1 and hypothesise that this might be mediated by E2F1. CONCLUSIONS We demonstrated the efficacy of the combination of ATM and EZH2 inhibition against BAP1-deficient mesothelioma in preclinical models, indicating the potential of this combination as a novel treatment modality using BAP1 as a biomarker.
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Affiliation(s)
- Nick Landman
- Division of Molecular Genetics, The Netherlands Cancer Institute, Plesmanlaan 121, Amsterdam, The Netherlands
- Oncode Institute, Jaarbeursplein 6, Utrecht, The Netherlands
| | - Danielle Hulsman
- Division of Molecular Genetics, The Netherlands Cancer Institute, Plesmanlaan 121, Amsterdam, The Netherlands
- Oncode Institute, Jaarbeursplein 6, Utrecht, The Netherlands
| | - Jitendra Badhai
- Division of Molecular Genetics, The Netherlands Cancer Institute, Plesmanlaan 121, Amsterdam, The Netherlands
- Oncode Institute, Jaarbeursplein 6, Utrecht, The Netherlands
| | - Jawahar Kopparam
- Division of Molecular Genetics, The Netherlands Cancer Institute, Plesmanlaan 121, Amsterdam, The Netherlands
- Oncode Institute, Jaarbeursplein 6, Utrecht, The Netherlands
| | - Julian Puppe
- Department of Obstetrics and Gynaecology, University Hospital of Cologne, Kerpener Str. 34, Cologne, Germany
| | - Gaurav Kumar Pandey
- Division of Molecular Genetics, The Netherlands Cancer Institute, Plesmanlaan 121, Amsterdam, The Netherlands.
- Oncode Institute, Jaarbeursplein 6, Utrecht, The Netherlands.
- Department of Zoology, Banaras Hindu University, Varanasi, Uttar Pradesh, India.
| | - Maarten van Lohuizen
- Division of Molecular Genetics, The Netherlands Cancer Institute, Plesmanlaan 121, Amsterdam, The Netherlands.
- Oncode Institute, Jaarbeursplein 6, Utrecht, The Netherlands.
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Vazquez-Villasenor I, Garwood CJ, Simpson JE, Heath PR, Mortiboys H, Wharton SB. Persistent DNA damage alters the neuronal transcriptome suggesting cell cycle dysregulation and altered mitochondrial function. Eur J Neurosci 2021; 54:6987-7005. [PMID: 34536321 DOI: 10.1111/ejn.15466] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2020] [Revised: 08/14/2021] [Accepted: 09/06/2021] [Indexed: 12/01/2022]
Abstract
Oxidative DNA damage induces changes in the neuronal cell cycle and activates a DNA damage response (DDR) to promote repair, but these processes may be altered under a chronic oxidative environment, leading to the accumulation of unrepaired DNA damage and continued activation of a DDR. Failure to repair DNA damage can lead to apoptosis or senescence, which is characterized by a permanent cell cycle arrest. Increased oxidative stress and accumulation of oxidative DNA damage are features of brain ageing and neurodegeneration, but the effects of persistent DNA damage in neurons are not well characterized. We developed a model of persistent oxidative DNA damage in immortalized post-mitotic neurons in vitro by exposing them to a sublethal concentration of hydrogen peroxide following a 'double stress' protocol and performed a detailed characterization of the neuronal transcriptome using microarray analysis. Persistent DNA damage significantly altered the expression of genes involved in cell cycle regulation, DDR and repair mechanisms, and mitochondrial function, suggesting an active DDR response to replication stress and alterations in mitochondrial electron transport chain. Quantitative polymerase chain reaction (qPCR) and functional validation experiments confirmed hyperactivation of mitochondrial Complex I in response to persistent DNA damage. These changes in response to persistent oxidative DNA damage may lead to further oxidative stress, contributing to neuronal dysfunction and ultimately neurodegeneration.
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Affiliation(s)
| | - Claire J Garwood
- Sheffield Institute for Translational Neuroscience, The University of Sheffield, Sheffield, UK
| | - Julie E Simpson
- Sheffield Institute for Translational Neuroscience, The University of Sheffield, Sheffield, UK
| | - Paul R Heath
- Sheffield Institute for Translational Neuroscience, The University of Sheffield, Sheffield, UK
| | - Heather Mortiboys
- Sheffield Institute for Translational Neuroscience, The University of Sheffield, Sheffield, UK
| | - Stephen B Wharton
- Sheffield Institute for Translational Neuroscience, The University of Sheffield, Sheffield, UK
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Prados-Carvajal R, Rodriguez-Real G, Gutierrez-Pozo G, Huertas P. CtIP -mediated alternative mRNA splicing finetunes the DNA damage response. RNA (NEW YORK, N.Y.) 2020; 27:rna.078519.120. [PMID: 33298529 PMCID: PMC7901839 DOI: 10.1261/rna.078519.120] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Accepted: 12/04/2020] [Indexed: 06/12/2023]
Abstract
In order to survive to the exposure of DNA damaging agents, cells activate a complex response that coordinates the cellular metabolism, cell cycle progression and DNA repair. Among many other events, recent evidence has described global changes in mRNA splicing in cells treated with genotoxic agents. Here, we explore further this DNA damage-dependent alternative splicing. Indeed, we show that both the splicing factor SF3B2 and the repair protein CtIP contribute to the global pattern of splicing both in cells treated or not to DNA damaging agents. Additionally, we focus on a specific DNA damage- and CtIP-dependent alternative splicing event of the helicase PIF1 and explore its relevance for the survival of cells upon exposure to ionizing radiation. Indeed, we described how the nuclear, active form of PIF1 is substituted by a splicing variant, named vPIF1, in a fashion that requires both the presence of DNA damage and CtIP. Interestingly, timely expression of vPIF1 is required for optimal survival to exposure to DNA damaging agents, but early expression of this isoform delays early events of the DNA damage response. On the contrary, expression of the full length PIF1 facilitates those early events, but increases the sensitivity to DNA damaging agents if the expression is maintained long-term.
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4
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Mello MB, Machado CS, Ribeiro DL, Aissa AF, Burim RV, Alves da Cunha MA, Barcelos GRM, Antunes LMG, Bianchi MLP. Protective effects of the exopolysaccharide Lasiodiplodan against DNA damage and inflammation induced by doxorubicin in rats: Cytogenetic and gene expression assays. Toxicology 2016; 376:66-74. [PMID: 27181935 DOI: 10.1016/j.tox.2016.05.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Revised: 05/06/2016] [Accepted: 05/12/2016] [Indexed: 12/29/2022]
Abstract
The lasiodiplodan (LS) is a β-(1→6)-d-glucan produced by the fungus Lasiodiplodia theobromae and some of the biological activities of LS were reported as hypoglycemic, anticoagulant, anti-proliferative and anticancer action; however, its effects on DNA instability and modulation of gene expression are still unclear. Aims of study were investigate the genotoxic effects of lasiodiplodan, and its protective activity against DNA damage induced by doxorubicin (DXR) and its impact on the expression of genes associated with DNA damage and inflammatory response pathways. Therefore, Wistar rats were treated (15 days) orally with LS (5.0; 10 and 20mg/kg bw) alone and in combination with DXR (15mg/kg bw; administrated intraperitoneally on 14th day) as well as their respective controls: distilled water and DXR. Monitoring of DNA damage was assessed by comet and micronucleus (MN) assays and gene expression was evaluated by PCR-Arrays. Treatments with LS alone did not induce disturbances on DNA; when LS was given in combination with DXR, comet and MN formations were reduced to those found in the respective controls. Moreover, LS was able to reduce the disturbances on gene expressions induced by DXR treatment, since the animals that receive LS associated with DXR showed no alteration in the expression of genes related to DNA damage response. Also, DXR induced several up- and down-regulation of several genes associated to inflammatory process, while the animals that received LS+DXR had their gene expression patterns similar to those found in the control group. In conclusion, our results showed that LS did not induce disturbances on DNA stability and significantly reduce the DNA damage and inflammation caused by DXR exposure. In addition, we give further information concerning the molecular mechanisms associated to LS protective effects which seems to be a promising nutraceutical with chemopreventive potential.
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Affiliation(s)
- M B Mello
- Department of Clinical Analyses, Toxicology and Food Sciences, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Avenida do Café s/n°, CEP 14040-903, Ribeirão Preto, São Paulo, Brazil
| | - C S Machado
- Department of Genetics; School of Medicine of Ribeirão Preto, University of São Paulo, Avenida Bandeirantes, 3900, CEP 14049-900, Ribeirão Preto, São Paulo, Brazil
| | - D L Ribeiro
- Department of Genetics; School of Medicine of Ribeirão Preto, University of São Paulo, Avenida Bandeirantes, 3900, CEP 14049-900, Ribeirão Preto, São Paulo, Brazil
| | - A F Aissa
- Department of Clinical Analyses, Toxicology and Food Sciences, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Avenida do Café s/n°, CEP 14040-903, Ribeirão Preto, São Paulo, Brazil
| | - R V Burim
- Department of Clinical Analyses, Toxicology and Food Sciences, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Avenida do Café s/n°, CEP 14040-903, Ribeirão Preto, São Paulo, Brazil
| | - M A Alves da Cunha
- Department of Chemistry, Federal University of Technology of Paraná, Via do Conhecimento, km 01, CEP 85503-390, Pato Branco, Paraná, Brazil
| | - G R M Barcelos
- Department of Clinical Analyses, Toxicology and Food Sciences, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Avenida do Café s/n°, CEP 14040-903, Ribeirão Preto, São Paulo, Brazil; Department of Biosciences, Institute of Health and Society, Federal University of São Paulo, Rua Silva Jardim, 136, CEP 11015-020, Santos, São Paulo, Brazil.
| | - L M G Antunes
- Department of Clinical Analyses, Toxicology and Food Sciences, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Avenida do Café s/n°, CEP 14040-903, Ribeirão Preto, São Paulo, Brazil
| | - M L P Bianchi
- Department of Clinical Analyses, Toxicology and Food Sciences, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Avenida do Café s/n°, CEP 14040-903, Ribeirão Preto, São Paulo, Brazil
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Podszywalow-Bartnicka P, Wolczyk M, Kusio-Kobialka M, Wolanin K, Skowronek K, Nieborowska-Skorska M, Dasgupta Y, Skorski T, Piwocka K. Downregulation of BRCA1 protein in BCR-ABL1 leukemia cells depends on stress-triggered TIAR-mediated suppression of translation. Cell Cycle 2015; 13:3727-41. [PMID: 25483082 DOI: 10.4161/15384101.2014.965013] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
BRCA1 tumor suppressor regulates crucial cellular processes involved in DNA damage repair and cell cycle control. We showed that expression of BCR-ABL1 correlates with decreased level of BRCA1 protein, which promoted aberrant mitoses and aneuploidy as well as altered DNA damage response. Using polysome profiling and luciferase-BRCA1 3'UTR reporter system here we demonstrate that downregulation of BRCA1 protein in CML is caused by inhibition of BRCA1 mRNA translation, but not by increased protein degradation or reduction of mRNA level and half-life. We investigated 2 mRNA-binding proteins - HuR and TIAR showing specificity to AU-Rich Element (ARE) sites in 3'UTR of mRNA. BCR-ABL1 promoted cytosolic localization of TIAR and HuR, their binding to BRCA1 mRNA and formation of the TIAR-HuR complex. HuR protein positively regulated BRCA1 mRNA stability and translation, conversely TIAR negatively regulated BRCA1 translation and was found localized predominantly in the cytosolic stress granules in CML cells. TIAR-dependent downregulation of BRCA1 protein level was a result of ER stress, which is activated in BCR-ABL1 expressing cells, as we previously shown. Silencing of TIAR in CML cells strongly elevated BRCA1 level. Altogether, we determined that TIAR-mediated repression of BRCA1 mRNA translation is responsible for downregulation of BRCA1 protein level in BCR-ABL1 -positive leukemia cells. This mechanism may contribute to genomic instability and provide justification for targeting PARP1 and/or RAD52 to induce synthetic lethality in "BRCAness" CML and BCR-ABL1 -positive ALL cells.
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Key Words
- ARE, AU-rich element
- ATM, Ataxia telangiectasia mutated kinase
- ATR, Ataxia telangiectasia and Rad3-related kinase
- BCR-ABL
- BRCA1
- BRCA1, Breast cancer type 1 susceptibility
- CML, chronic myeloid leukemia
- DNA damage response
- HuR
- HuR, Hu antigen R (alternative name: ELAV-like protein 1)
- TIAR
- TIAR, TIA1 cytotoxic granule-associated RNA-binding protein-like 1
- UPR, unfolded protein response
- UTR, untranslated region
- cell cycle
- eIF, eukaryotic initiation factor
- mRNA binding protein
- stress response
- synthetic lethality
- translation
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Labanca E, De Luca P, Gueron G, Paez A, Moiola CP, Massillo C, Porretti J, Giudice J, Zalazar F, Navone N, Vazquez E, De Siervi A. Association of HO-1 and BRCA1 Is Critical for the Maintenance of Cellular Homeostasis in Prostate Cancer. Mol Cancer Res 2015; 13:1455-64. [PMID: 26227317 DOI: 10.1158/1541-7786.mcr-15-0150-t] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Accepted: 07/22/2015] [Indexed: 11/16/2022]
Abstract
UNLABELLED Prostate cancer is the second leading cause of cancer-related death in men worldwide. Many factors that participate in the development of prostate cancer promote imbalance in the redox state of the cell. Accumulation of reactive oxygen species causes injury to cell structures, ultimately leading to cancer development. The antioxidant enzyme heme oxygenase 1 (HMOX1/HO-1) is responsible for the maintenance of the cellular homeostasis, playing a critical role in the oxidative stress and the regulation of prostate cancer development and progression. In the present study, the transcriptional regulation of HO-1 was investigated in prostate cancer. Interestingly, the tumor suppressor BRCA1 binds to the HO-1 promoter and modulates HO-1, inducing its protein levels through both the increment of its promoter activity and the induction of its transcriptional activation. In addition, in vitro and in vivo analyses show that BRCA1 also controls HO-1-negative targets: MMP9, uPA, and Cyclin D1. HO-1 transcriptional regulation is also modulated by oxidative and genotoxic agents. Induction of DNA damage by mitoxantrone and etoposide repressed HO-1 transcription, whereas hydrogen peroxide and doxorubicin induced its expression. Xenograft studies showed that HO-1 regulation by doxorubicin also occurs in vivo. Immunofluorescence analysis revealed that BRCA1 overexpression and/or doxorubicin exposure induced the cytoplasmic retention of HO-1. Finally, the transcription factor NRF2 cooperates with BRCA1 protein to activate HO-1 promoter activity. In summary, these results show that the activation of BRCA1-NRF2/HO-1 axis defines a new mechanism for the maintenance of the cellular homeostasis in prostate cancer. IMPLICATIONS Oxidative and genotoxic stress converge on HO-1 transcriptional activity through the combined actions of BRCA1 and NRF2.
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Affiliation(s)
- Estefanía Labanca
- Laboratorio de Oncología Molecular y Nuevos Blancos Terapéuticos, Instituto de Biologia y Medicina Experimental (IBYME)-CONICET, Buenos Aires, Argentina. Laboratorio de Inflamación y Cáncer, Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales (FCEN), Universidad de Buenos Aires (UBA), IQUIBICEN-CONICET, Buenos Aires, Argentina
| | - Paola De Luca
- Laboratorio de Oncología Molecular y Nuevos Blancos Terapéuticos, Instituto de Biologia y Medicina Experimental (IBYME)-CONICET, Buenos Aires, Argentina
| | - Geraldine Gueron
- Laboratorio de Inflamación y Cáncer, Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales (FCEN), Universidad de Buenos Aires (UBA), IQUIBICEN-CONICET, Buenos Aires, Argentina
| | - Alejandra Paez
- Laboratorio de Inflamación y Cáncer, Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales (FCEN), Universidad de Buenos Aires (UBA), IQUIBICEN-CONICET, Buenos Aires, Argentina
| | - Cristian P Moiola
- Laboratorio de Oncología Molecular y Nuevos Blancos Terapéuticos, Instituto de Biologia y Medicina Experimental (IBYME)-CONICET, Buenos Aires, Argentina
| | - Cintia Massillo
- Laboratorio de Oncología Molecular y Nuevos Blancos Terapéuticos, Instituto de Biologia y Medicina Experimental (IBYME)-CONICET, Buenos Aires, Argentina
| | - Juliana Porretti
- Laboratorio de Oncología Molecular y Nuevos Blancos Terapéuticos, Instituto de Biologia y Medicina Experimental (IBYME)-CONICET, Buenos Aires, Argentina
| | - Jimena Giudice
- Department of Pathology and Immunology, Baylor College of Medicine, Houston, Texas
| | - Florencia Zalazar
- Laboratorio de Oncología Molecular y Nuevos Blancos Terapéuticos, Instituto de Biologia y Medicina Experimental (IBYME)-CONICET, Buenos Aires, Argentina
| | - Nora Navone
- Department of Genitourinary Medical Oncology, The University of Texas, M. D. Anderson Cancer Center, Houston, Texas
| | - Elba Vazquez
- Laboratorio de Inflamación y Cáncer, Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales (FCEN), Universidad de Buenos Aires (UBA), IQUIBICEN-CONICET, Buenos Aires, Argentina
| | - Adriana De Siervi
- Laboratorio de Oncología Molecular y Nuevos Blancos Terapéuticos, Instituto de Biologia y Medicina Experimental (IBYME)-CONICET, Buenos Aires, Argentina.
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Bozickovic O, Hoang T, Fenne IS, Helland T, Skartveit L, Ouchida M, Mellgren G, Sagen JV. Cyclin C interacts with steroid receptor coactivator 2 and upregulates cell cycle genes in MCF-7 cells. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2015; 1853:2383-91. [PMID: 25986860 DOI: 10.1016/j.bbamcr.2015.05.016] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Revised: 04/23/2015] [Accepted: 05/09/2015] [Indexed: 11/16/2022]
Abstract
Steroid receptor coactivator 2 (SRC-2) is a coactivator that regulates nuclear receptor activity. We previously reported that SRC-2 protein is degraded through the action of cAMP-dependent protein kinase A (PKA) and cAMP response element binding protein (CREB). In the study presented here, we aimed to identify proteins that interact with and thereby regulate SRC-2. We isolated cyclin C (CCNC) as an interacting partner with the SRC-2 degradation domain aa 347-758 in a yeast two-hybrid assay and confirmed direct interaction in an in vitro assay. The protein level of SRC-2 was increased with CCNC overexpression in COS-1 cells and decreased with CCNC silencing in COS-1 and MCF-7 cells. In a pulse-chase assay, we further show that silencing of CCNC resulted in a different SRC-2 degradation pattern during the first 6 h after the pulse. Finally, we provide evidence that CCNC regulates expression of cell cycle genes upregulated by SRC-2. In conclusion, our results suggest that CCNC temporarily protects SRC-2 against degradation and this event is involved in the transcriptional regulation of SRC-2 cell cycle target genes.
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Affiliation(s)
- Olivera Bozickovic
- Department of Clinical Science, University of Bergen, Bergen N-5021, Norway; Hormone Laboratory, Haukeland University Hospital, Bergen N-5021, Norway.
| | - Tuyen Hoang
- Department of Clinical Science, University of Bergen, Bergen N-5021, Norway.
| | - Ingvild S Fenne
- Department of Clinical Science, University of Bergen, Bergen N-5021, Norway; Hormone Laboratory, Haukeland University Hospital, Bergen N-5021, Norway.
| | - Thomas Helland
- Department of Clinical Science, University of Bergen, Bergen N-5021, Norway; Hormone Laboratory, Haukeland University Hospital, Bergen N-5021, Norway.
| | - Linn Skartveit
- Department of Clinical Science, University of Bergen, Bergen N-5021, Norway; Hormone Laboratory, Haukeland University Hospital, Bergen N-5021, Norway.
| | - Mamoru Ouchida
- Department of Molecular Genetics, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan.
| | - Gunnar Mellgren
- Department of Clinical Science, University of Bergen, Bergen N-5021, Norway; Hormone Laboratory, Haukeland University Hospital, Bergen N-5021, Norway.
| | - Jørn V Sagen
- Department of Clinical Science, University of Bergen, Bergen N-5021, Norway; Hormone Laboratory, Haukeland University Hospital, Bergen N-5021, Norway.
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Liu B, Cong R, Peng B, Zhu B, Dou G, Ai H, Zhang X, Wang Z, Xu X. CtIP is required for DNA damage-dependent induction of P21. Cell Cycle 2013; 13:90-5. [PMID: 24196441 PMCID: PMC3925741 DOI: 10.4161/cc.26810] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
DNA endonuclease CtIP is involved in both DNA double-strand break (DSB) repair and transcriptional repression/activation. The cyclin-dependent kinase inhibitor P21, which is induced at transcription level in response to a variety of stresses, controls G₁/S transition. In this report, we found that CtIP bound to the P21 promoter, and this binding was enhanced in response to DNA damage. Concomitantly, ectopic expression of CtIP increased P21 promoter activity, and this increment was enhanced upon camptothecin treatment. Conversely, DNA damage failed to induce P21 gene expression in CtIP-deficient cells. Taken together, our data demonstrate that CtIP is required for DNA damage-induced P21 induction.
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Affiliation(s)
- Bo Liu
- Beijing Key laboratory of DNA Damage Response; Capital Normal University; College of Life Sciences; Beijing, China
| | - Rixin Cong
- Beijing Key laboratory of DNA Damage Response; Capital Normal University; College of Life Sciences; Beijing, China
| | - Bin Peng
- Beijing Key laboratory of DNA Damage Response; Capital Normal University; College of Life Sciences; Beijing, China
| | - Bingtao Zhu
- Beijing Key laboratory of DNA Damage Response; Capital Normal University; College of Life Sciences; Beijing, China
| | - Gelin Dou
- Beijing Key laboratory of DNA Damage Response; Capital Normal University; College of Life Sciences; Beijing, China
| | - Haiyan Ai
- Beijing Key laboratory of DNA Damage Response; Capital Normal University; College of Life Sciences; Beijing, China
| | - Xiaodong Zhang
- College of Life Sciences; Wuhan University; Wuhan, Hubei, China
| | - Zhenghe Wang
- Department of Genetics and Case Comprehensive Cancer Center; Case Western Reserve University; Cleveland, OH USA
| | - Xingzhi Xu
- Beijing Key laboratory of DNA Damage Response; Capital Normal University; College of Life Sciences; Beijing, China
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9
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BRCA1 and p53 regulate critical prostate cancer pathways. Prostate Cancer Prostatic Dis 2013; 16:233-8. [PMID: 23670255 DOI: 10.1038/pcan.2013.12] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2012] [Revised: 03/13/2013] [Accepted: 03/30/2013] [Indexed: 12/14/2022]
Abstract
BACKGROUND Loss or mutations of the BRCA1 gene are associated with increased risk of breast and ovarian cancers and with prostate cancer (PCa) aggressiveness. Previously, we identified GADD153 as a target of BRCA1 protein, which increases doxorubicin sensitivity in human p53 -/- PCa cells (PC3). Considering that p53 is a crucial target in cancer therapy, in this work we investigated p53 role in the regulation of transcription of GADD153. METHODS We performed reverse transcription quantitative PCR (RT-qPCR), western blot and luciferase assays to analyze GADD153 and/or BRCA1 expression in response to ultraviolet or doxorubicin exposure in PC3 p53 stable-transfected cells and LNCaP (p53+/+) cells. BRCA1 protein recruitment to GADD153 promoter was studied by chromatin immunoprecipitation-qPCR. To assess expression of BRCA1 and/or p53 target genes, we used a panel of stable-transfected PCa cell lines. We finally analyzed these genes in vivo using BRCA1-depleted PCa xenograft models. RESULTS We found that GADD153 was highly induced by doxorubicin in PC3 cells; however, this response was totally abolished in LNCaP (p53wt) and in p53-restituted PC3 cells. Furthermore, BRCA1 protein associates to GADD153 promoter after DNA damage in the presence of p53. Additionally, we demonstrated that BRCA1 and/or p53 modulate genes involved in DNA damage and cell cycle regulation (cyclin D1, BLM, BRCA2, DDB2, p21(WAF1/CIP1), H3F3B, GADD153, GADD45A, FEN1, CCNB2), EMT (E-cadherin, β-catenin, vimentin, fibronectin, slug, snail) and Hedgehog pathways (SHH, IHH, DHH, Gli1, PATCH1). Furthermore, xenograft studies demonstrated that BRCA1 knockdown in PC3 cells increased tumor growth and modulated these genes in vivo. CONCLUSIONS Although BRCA1 induces GADD153 in a p53 independent manner, p53 abolished GADD153 induction in response to DNA damage. In addition, several important PCa targets are modulated by BRCA1 and p53. Altogether, these data might be important to understand the therapy response of PCa patients.
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