1
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Integrative bioinformatic analysis of p53 and pathway alterations in two different lung cancer subtypes. Biochem Biophys Rep 2023; 33:101404. [DOI: 10.1016/j.bbrep.2022.101404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 11/13/2022] [Accepted: 12/01/2022] [Indexed: 12/12/2022] Open
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2
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Carlsen L, El-Deiry WS. Differential p53-Mediated Cellular Responses to DNA-Damaging Therapeutic Agents. Int J Mol Sci 2021; 22:ijms222111828. [PMID: 34769259 PMCID: PMC8584119 DOI: 10.3390/ijms222111828] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 10/29/2021] [Accepted: 10/29/2021] [Indexed: 01/01/2023] Open
Abstract
The gene TP53, which encodes the tumor suppressor protein p53, is mutated in about 50% of cancers. In response to cell stressors like DNA damage and after treatment with DNA-damaging therapeutic agents, p53 acts as a transcription factor to activate subsets of target genes which carry out cell fates such as apoptosis, cell cycle arrest, and DNA repair. Target gene selection by p53 is controlled by a complex regulatory network whose response varies across contexts including treatment type, cell type, and tissue type. The molecular basis of target selection across these contexts is not well understood. Knowledge gained from examining p53 regulatory network profiles across different DNA-damaging agents in different cell types and tissue types may inform logical ways to optimally manipulate the network to encourage p53-mediated tumor suppression and anti-tumor immunity in cancer patients. This may be achieved with combination therapies or with p53-reactivating targeted therapies. Here, we review the basics of the p53 regulatory network in the context of differential responses to DNA-damaging agents; discuss recent efforts to characterize differential p53 responses across treatment types, cell types, and tissue types; and examine the relevance of evaluating these responses in the tumor microenvironment. Finally, we address open questions including the potential relevance of alternative p53 transcriptional functions, p53 transcription-independent functions, and p53-independent functions in the response to DNA-damaging therapeutics.
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Affiliation(s)
- Lindsey Carlsen
- Laboratory of Translational Oncology and Experimental Cancer Therapeutics, The Warren Alpert Medical School, Brown University, Providence, RI 02903, USA;
- The Joint Program in Cancer Biology, Brown University and the Lifespan Health System, Providence, RI 02903, USA
- Department of Pathology and Laboratory Medicine, The Warren Alpert Medical School, Brown University, Providence, RI 02903, USA
- Pathobiology Graduate Program, The Warren Alpert Medical School, Brown University, Providence, RI 02903, USA
- Cancer Center, The Warren Alpert Medical School, Brown University, Providence, RI 02903, USA
| | - Wafik S. El-Deiry
- Laboratory of Translational Oncology and Experimental Cancer Therapeutics, The Warren Alpert Medical School, Brown University, Providence, RI 02903, USA;
- The Joint Program in Cancer Biology, Brown University and the Lifespan Health System, Providence, RI 02903, USA
- Department of Pathology and Laboratory Medicine, The Warren Alpert Medical School, Brown University, Providence, RI 02903, USA
- Pathobiology Graduate Program, The Warren Alpert Medical School, Brown University, Providence, RI 02903, USA
- Cancer Center, The Warren Alpert Medical School, Brown University, Providence, RI 02903, USA
- Department of Medicine, Hematology-Oncology Division, Rhode Island Hospital, Brown University, Providence, RI 02903, USA
- Correspondence:
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3
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p53-Dependent Repression: DREAM or Reality? Cancers (Basel) 2021; 13:cancers13194850. [PMID: 34638334 PMCID: PMC8508069 DOI: 10.3390/cancers13194850] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 09/23/2021] [Accepted: 09/24/2021] [Indexed: 12/22/2022] Open
Abstract
Simple Summary The tumor suppressor p53 is a complex cell signaling hub encompassing multiple transcription programs and governs a vast repertoire of biological responses. However, despite several decades of research, how p53 selects one program over another is still elusive. Recent attempts have used meta-analyses of p53 ChIP-seq data to determine the core p53 transcriptional program, conserved across different models and stimuli. This review highlights the complexity of the multiple layers of p53 regulation and the context specificity of p53 target genes. More specifically, we discuss the controversy over the mechanisms of p53-dependent transcriptional repression and its potential role in the flexibility of p53 response. Abstract p53 is a major tumor suppressor that integrates diverse types of signaling in mammalian cells. In response to a broad range of intra- or extra-cellular stimuli, p53 controls the expression of multiple target genes and elicits a vast repertoire of biological responses. The exact code by which p53 integrates the various stresses and translates them into an appropriate transcriptional response is still obscure. p53 is tightly regulated at multiple levels, leading to a wide diversity in p53 complexes on its target promoters and providing adaptability to its transcriptional program. As p53-targeted therapies are making their way into clinics, we need to understand how to direct p53 towards the desired outcome (i.e., cell death, senescence or other) selectively in cancer cells without affecting normal tissues or the immune system. While the core p53 transcriptional program has been proposed, the mechanisms conferring a cell type- and stimuli-dependent transcriptional outcome by p53 require further investigations. The mechanism by which p53 localizes to repressed promoters and manages its co-repressor interactions is controversial and remains an important gap in our understanding of the p53 cistrome. We hope that our review of the recent literature will help to stimulate the appreciation and investigation of largely unexplored p53-mediated repression.
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4
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Carlsen L, Schorl C, Huntington K, Hernandez-Borrero L, Jhaveri A, Zhang S, Zhou L, El-Deiry WS. Pan-drug and drug-specific mechanisms of 5-FU, irinotecan (CPT-11), oxaliplatin, and cisplatin identified by comparison of transcriptomic and cytokine responses of colorectal cancer cells. Oncotarget 2021; 12:2006-2021. [PMID: 34611476 PMCID: PMC8487728 DOI: 10.18632/oncotarget.28075] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Accepted: 08/28/2021] [Indexed: 12/12/2022] Open
Abstract
Colorectal cancer (CRC) caused over 900,000 deaths worldwide in 2020. A majority of late-stage CRC patients are treated with 5-fluorouracil (5-FU) combined with either irinotecan (CPT-11), oxaliplatin, or both. Despite their widespread use, the mechanisms of efficacy and toxicity of these drugs remain incompletely understood. While previous work has investigated cellular responses to these agents individually, we directly compare the transcriptomic and cytokine profiles of HCT116 wild-type and p53-/- colorectal cancer cells treated with these drugs and report pan-drug, drug-specific, drug class-specific, p53-independent, and p53-dependent signatures. We observed downregulation of histone genes by 5-FU (that significantly correlates with improved survival in CRC patients) and upregulation of FOS and ATF3 by oxaliplatin (which may contribute to peripheral neuropathy). BTG2 was identified as a top gene upregulated by all four drugs, suggesting its critical role in the cellular response to chemotherapy in CRC. Soluble TRAILR2 (death receptor 5; DR5) is a decoy receptor for TRAIL, an apoptosis-inducing cytokine. TRAILR2 was down-regulated by oxaliplatin and 5-FU, was not affected by CPT-11, and was increased by cisplatin. There was an increase in IL-8 by oxaliplatin and increase in ferritin by cisplatin which may contribute to cancer cell survival. Novel drug-specific mechanisms of efficacy or toxicity identified in these signatures may be targeted with combination therapies or development of new targeted therapies. Together, the findings here contribute to our understanding of the molecular bases of efficacy and toxicity of chemotherapeutic agents often used for treatment of GI cancer such as CRC.
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Affiliation(s)
- Lindsey Carlsen
- Laboratory of Translational Oncology and Experimental Cancer Therapeutics, The Warren Alpert Medical School, Brown University, Providence, RI 02903, USA.,The Joint Program in Cancer Biology, Brown University and the Lifespan Health System, Providence, RI 02903, USA.,Department of Pathology and Laboratory Medicine, The Warren Alpert Medical School, Brown University, Providence, RI 02903, USA.,Pathobiology Graduate Program, The Warren Alpert Medical School, Brown University, Providence, RI 02903, USA
| | - Christoph Schorl
- The Joint Program in Cancer Biology, Brown University and the Lifespan Health System, Providence, RI 02903, USA.,Department of Molecular Biology, Cell Biology and Biochemistry, The Warren Alpert Medical School, Brown University, Providence, RI 02903, USA.,Genomics Core Facility, Brown University, Providence, RI 02903, USA.,Cancer Center at Brown University, The Warren Alpert Medical School, Brown University, Providence, RI 02903, USA
| | - Kelsey Huntington
- Laboratory of Translational Oncology and Experimental Cancer Therapeutics, The Warren Alpert Medical School, Brown University, Providence, RI 02903, USA.,The Joint Program in Cancer Biology, Brown University and the Lifespan Health System, Providence, RI 02903, USA.,Department of Pathology and Laboratory Medicine, The Warren Alpert Medical School, Brown University, Providence, RI 02903, USA.,Pathobiology Graduate Program, The Warren Alpert Medical School, Brown University, Providence, RI 02903, USA
| | - Liz Hernandez-Borrero
- Laboratory of Translational Oncology and Experimental Cancer Therapeutics, The Warren Alpert Medical School, Brown University, Providence, RI 02903, USA.,The Joint Program in Cancer Biology, Brown University and the Lifespan Health System, Providence, RI 02903, USA.,Department of Pathology and Laboratory Medicine, The Warren Alpert Medical School, Brown University, Providence, RI 02903, USA.,Pathobiology Graduate Program, The Warren Alpert Medical School, Brown University, Providence, RI 02903, USA
| | - Aakash Jhaveri
- Laboratory of Translational Oncology and Experimental Cancer Therapeutics, The Warren Alpert Medical School, Brown University, Providence, RI 02903, USA.,Department of Pathology and Laboratory Medicine, The Warren Alpert Medical School, Brown University, Providence, RI 02903, USA
| | - Shengliang Zhang
- Laboratory of Translational Oncology and Experimental Cancer Therapeutics, The Warren Alpert Medical School, Brown University, Providence, RI 02903, USA.,The Joint Program in Cancer Biology, Brown University and the Lifespan Health System, Providence, RI 02903, USA.,Department of Pathology and Laboratory Medicine, The Warren Alpert Medical School, Brown University, Providence, RI 02903, USA.,Cancer Center at Brown University, The Warren Alpert Medical School, Brown University, Providence, RI 02903, USA
| | - Lanlan Zhou
- Laboratory of Translational Oncology and Experimental Cancer Therapeutics, The Warren Alpert Medical School, Brown University, Providence, RI 02903, USA.,The Joint Program in Cancer Biology, Brown University and the Lifespan Health System, Providence, RI 02903, USA.,Department of Pathology and Laboratory Medicine, The Warren Alpert Medical School, Brown University, Providence, RI 02903, USA.,Cancer Center at Brown University, The Warren Alpert Medical School, Brown University, Providence, RI 02903, USA
| | - Wafik S El-Deiry
- Laboratory of Translational Oncology and Experimental Cancer Therapeutics, The Warren Alpert Medical School, Brown University, Providence, RI 02903, USA.,The Joint Program in Cancer Biology, Brown University and the Lifespan Health System, Providence, RI 02903, USA.,Department of Pathology and Laboratory Medicine, The Warren Alpert Medical School, Brown University, Providence, RI 02903, USA.,Pathobiology Graduate Program, The Warren Alpert Medical School, Brown University, Providence, RI 02903, USA.,Hematology-Oncology Division, Department of Medicine, Rhode Island Hospital and Brown University, Providence, RI 02903, USA.,Cancer Center at Brown University, The Warren Alpert Medical School, Brown University, Providence, RI 02903, USA
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5
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Weyerer V, Strissel PL, Stöhr C, Eckstein M, Wach S, Taubert H, Brandl L, Geppert CI, Wullich B, Cynis H, Beckmann MW, Seliger B, Hartmann A, Strick R. Endogenous Retroviral-K Envelope Is a Novel Tumor Antigen and Prognostic Indicator of Renal Cell Carcinoma. Front Oncol 2021; 11:657187. [PMID: 33968761 PMCID: PMC8100683 DOI: 10.3389/fonc.2021.657187] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Accepted: 04/06/2021] [Indexed: 11/13/2022] Open
Abstract
Renal cell carcinoma (RCC) is one of the ten most common cancers for men and women with an approximate 75% overall 5-year survival. Sixteen histological tumor subtypes exist and the most common are papillary, chromophobe and clear cell renal cell carcinoma (ccRCC) representing 85% of all RCC. Although epigenetically silenced, endogenous retroviral (ERV) genes become activated in tumors and function to ignite immune responses. Research has intensified to understand ERV protein function and their role as tumor antigens and targets for cancer (immune) therapy. ERV-K env is overexpressed and implicated as a therapeutic target for breast cancer, however studies in RCC are limited. In this investigation a human RCC tissue microarray (TMA) (n=374) predominantly consisting of the most common histological tumor subtypes was hybridized with an ERV-K env antibody and correlated with patient clinical data. TMA results showed the highest amount of ERV-K env protein expression and the strongest significant membrane expression in ccRCC versus other RCC subtypes. High ERV-K env total protein expression of all tumor subtypes significantly correlated with low tumor grading and a longer disease specific survival using multivariable analyses. Cell proliferation and invasion were assayed using the kidney cell lines HEK293 with wild-type p53 and a ccRCC cell line MZ1257RC mutated for p53. Transfecting these cell lines with a codon optimized ERV-K113 env overexpressing CMV vector was performed with or without 5’-Aza-2’-deoxycytidine (Aza) treatment to sustain promoter de-methylation. MZ1257RC showed induction of ERV-K113 expression and significantly increased both proliferation and invasion in the presence or absence of Aza. HEK293 cells demonstrated a restriction of ERV-K113 env expression and invasion with no changes in proliferation in the absence of Aza. However, in the presence of Aza despite increased ERV-K113 env expression, an inhibition of HEK293 proliferation and a further restriction of invasion was found. This study supports ERV-K env as a single prognostic indicator for better survival of RCC, which we propose represents a new tumor antigen. In addition, ERV-K env significantly regulates proliferation and invasion depending on p53 status and Aza treatment.
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Affiliation(s)
- Veronika Weyerer
- Institute of Pathology, University Hospital Erlangen, Friedrich-Alexander University Erlangen-Nuernberg, Erlangen, Germany
| | - Pamela L Strissel
- Institute of Pathology, University Hospital Erlangen, Friedrich-Alexander University Erlangen-Nuernberg, Erlangen, Germany.,Department of Gynecology and Obstetrics, University Hospital Erlangen, Comprehensive Cancer Center, European Metropolitan Area Erlangen-Nuremberg (CCC ER-EMN), Friedrich-Alexander-University Erlangen-Nuernberg, Erlangen, Germany.,Adjunct Affiliation With Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Christine Stöhr
- Institute of Pathology, University Hospital Erlangen, Friedrich-Alexander University Erlangen-Nuernberg, Erlangen, Germany
| | - Markus Eckstein
- Institute of Pathology, University Hospital Erlangen, Friedrich-Alexander University Erlangen-Nuernberg, Erlangen, Germany
| | - Sven Wach
- Department of Urology and Pediatric Urology, University Hospital Erlangen, Friedrich-Alexander University Erlangen-Nuernberg, Erlangen, Germany
| | - Helge Taubert
- Department of Urology and Pediatric Urology, University Hospital Erlangen, Friedrich-Alexander University Erlangen-Nuernberg, Erlangen, Germany
| | - Lisa Brandl
- Institute of Pathology, University Hospital Erlangen, Friedrich-Alexander University Erlangen-Nuernberg, Erlangen, Germany
| | - Carol I Geppert
- Institute of Pathology, University Hospital Erlangen, Friedrich-Alexander University Erlangen-Nuernberg, Erlangen, Germany
| | - Bernd Wullich
- Department of Urology and Pediatric Urology, University Hospital Erlangen, Friedrich-Alexander University Erlangen-Nuernberg, Erlangen, Germany
| | - Holger Cynis
- Department of Drug Design and Target Validation, Fraunhofer Institute for Cell Therapy and Immunology, Halle, Germany
| | - Matthias W Beckmann
- Department of Gynecology and Obstetrics, University Hospital Erlangen, Comprehensive Cancer Center, European Metropolitan Area Erlangen-Nuremberg (CCC ER-EMN), Friedrich-Alexander-University Erlangen-Nuernberg, Erlangen, Germany
| | - Barbara Seliger
- Institute of Medical Immunology, Martin Luther University Halle-Wittenberg, Halle, Germany
| | - Arndt Hartmann
- Institute of Pathology, University Hospital Erlangen, Friedrich-Alexander University Erlangen-Nuernberg, Erlangen, Germany
| | - Reiner Strick
- Department of Gynecology and Obstetrics, University Hospital Erlangen, Comprehensive Cancer Center, European Metropolitan Area Erlangen-Nuremberg (CCC ER-EMN), Friedrich-Alexander-University Erlangen-Nuernberg, Erlangen, Germany.,Translational Research Centre (TRC), Erlangen, Germany
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6
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Freewoman JM, Snape R, Cui F. Temporal gene regulation by p53 is associated with the rotational setting of its binding sites in nucleosomes. Cell Cycle 2021; 20:792-807. [PMID: 33764853 PMCID: PMC8098069 DOI: 10.1080/15384101.2021.1904554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
The tumor suppressor protein p53 is a DNA-binding transcription factor (TF) that, once activated, coordinates the expression of thousands of target genes. Increased p53 binding to gene promoters occurs shortly after p53 activation. Intriguingly, gene transcription exhibits differential kinetics with some genes being induced early (early genes) and others being induced late (late genes). To understand pre-binding factors contributing to the temporal gene regulation by p53, we performed time-course RNA sequencing experiments in human colon cancer cell line HCT116 treated with fluorouracil to identify early and late genes. Published p53 ChIP fragments co-localized with the early or late genes were used to uncover p53 binding sites (BS). We demonstrate that the BS associated with early genes are clustered around gene starts with decreased nucleosome occupancy. DNA analysis shows that these BS are likely exposed on nucleosomal surface if wrapped into nucleosomes, thereby facilitating stable interactions with and fast induction by p53. By contrast, p53 BS associated with late genes are distributed uniformly across the genes with increased nucleosome occupancy. Predicted rotational settings of these BS show limited accessibility. We therefore propose a hypothetical model in which the BS are fully, partially or not accessible to p53 in the nucleosomal context. The partial accessibility of the BS allows subunits of a p53 tetramer to bind, but the resulting p53-DNA complex may not be stable enough to recruit cofactors, which leads to delayed induction. Our work highlights the importance of DNA conformations of p53 BS in gene expression dynamics.
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Affiliation(s)
- Julia M Freewoman
- Thomas H. Gosnell School of Life Sciences, College of Science, Rochester Institute of Technology, Rochester, NY, USA
| | - Rajiv Snape
- Thomas H. Gosnell School of Life Sciences, College of Science, Rochester Institute of Technology, Rochester, NY, USA
| | - Feng Cui
- Thomas H. Gosnell School of Life Sciences, College of Science, Rochester Institute of Technology, Rochester, NY, USA
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7
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Sammons MA, Nguyen TAT, McDade SS, Fischer M. Tumor suppressor p53: from engaging DNA to target gene regulation. Nucleic Acids Res 2020; 48:8848-8869. [PMID: 32797160 PMCID: PMC7498329 DOI: 10.1093/nar/gkaa666] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2020] [Revised: 07/24/2020] [Accepted: 07/30/2020] [Indexed: 12/13/2022] Open
Abstract
The p53 transcription factor confers its potent tumor suppressor functions primarily through the regulation of a large network of target genes. The recent explosion of next generation sequencing protocols has enabled the study of the p53 gene regulatory network (GRN) and underlying mechanisms at an unprecedented depth and scale, helping us to understand precisely how p53 controls gene regulation. Here, we discuss our current understanding of where and how p53 binds to DNA and chromatin, its pioneer-like role, and how this affects gene regulation. We provide an overview of the p53 GRN and the direct and indirect mechanisms through which p53 affects gene regulation. In particular, we focus on delineating the ubiquitous and cell type-specific network of regulatory elements that p53 engages; reviewing our understanding of how, where, and when p53 binds to DNA and the mechanisms through which these events regulate transcription. Finally, we discuss the evolution of the p53 GRN and how recent work has revealed remarkable differences between vertebrates, which are of particular importance to cancer researchers using mouse models.
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Affiliation(s)
- Morgan A Sammons
- Department of Biological Sciences and The RNA Institute, University at Albany, State University of New York, 1400 Washington Avenue, Albany, NY 12222, USA
| | - Thuy-Ai T Nguyen
- Genome Integrity & Structural Biology Laboratory and Immunity, Inflammation and Disease Laboratory, National Institute of Environmental Health Sciences/National Institutes of Health, 111 TW Alexander Drive, Research Triangle Park, NC 27709, USA
| | - Simon S McDade
- Patrick G Johnston Centre for Cancer Research, Queen's University Belfast, 97 Lisburn Road, Belfast BT9 7AE, UK
| | - Martin Fischer
- Computational Biology Group, Leibniz Institute on Aging – Fritz Lipmann Institute (FLI), Beutenbergstraße 11, 07745 Jena, Germany
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8
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Nguyen TAT, Grimm SA, Bushel PR, Li J, Li Y, Bennett BD, Lavender CA, Ward JM, Fargo DC, Anderson CW, Li L, Resnick MA, Menendez D. Revealing a human p53 universe. Nucleic Acids Res 2019; 46:8153-8167. [PMID: 30107566 PMCID: PMC6144829 DOI: 10.1093/nar/gky720] [Citation(s) in RCA: 64] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Accepted: 07/27/2018] [Indexed: 12/13/2022] Open
Abstract
p53 transcriptional networks are well-characterized in many organisms. However, a global understanding of requirements for in vivo p53 interactions with DNA and relationships with transcription across human biological systems in response to various p53 activating situations remains limited. Using a common analysis pipeline, we analyzed 41 data sets from genome-wide ChIP-seq studies of which 16 have associated gene expression data, including our recent primary data with normal human lymphocytes. The resulting extensive analysis, accessible at p53 BAER hub via the UCSC browser, provides a robust platform to characterize p53 binding throughout the human genome including direct influence on gene expression and underlying mechanisms. We establish the impact of spacers and mismatches from consensus on p53 binding in vivo and propose that once bound, neither significantly influences the likelihood of expression. Our rigorous approach revealed a large p53 genome-wide cistrome composed of >900 genes directly targeted by p53. Importantly, we identify a core cistrome signature composed of genes appearing in over half the data sets, and we identify signatures that are treatment- or cell-specific, demonstrating new functions for p53 in cell biology. Our analysis reveals a broad homeostatic role for human p53 that is relevant to both basic and translational studies.
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Affiliation(s)
- Thuy-Ai T Nguyen
- Genome Integrity & Structural Biology Laboratory, National Institute of Environmental Health Sciences/National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Sara A Grimm
- Integrative Bioinformatics Support Group, National Institute of Environmental Health Sciences/National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Pierre R Bushel
- Biostatistics & Computational Biology Branch, National Institute of Environmental Health Sciences/National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Jianying Li
- Integrative Bioinformatics Support Group, National Institute of Environmental Health Sciences/National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Yuanyuan Li
- Biostatistics & Computational Biology Branch, National Institute of Environmental Health Sciences/National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Brian D Bennett
- Integrative Bioinformatics Support Group, National Institute of Environmental Health Sciences/National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Christopher A Lavender
- Integrative Bioinformatics Support Group, National Institute of Environmental Health Sciences/National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - James M Ward
- Integrative Bioinformatics Support Group, National Institute of Environmental Health Sciences/National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - David C Fargo
- Integrative Bioinformatics Support Group, National Institute of Environmental Health Sciences/National Institutes of Health, Research Triangle Park, NC 27709, USA.,Office of Scientific Computing, National Institute of Environmental Health Sciences/National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Carl W Anderson
- Genome Integrity & Structural Biology Laboratory, National Institute of Environmental Health Sciences/National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Leping Li
- Biostatistics & Computational Biology Branch, National Institute of Environmental Health Sciences/National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Michael A Resnick
- Genome Integrity & Structural Biology Laboratory, National Institute of Environmental Health Sciences/National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Daniel Menendez
- Genome Integrity & Structural Biology Laboratory, National Institute of Environmental Health Sciences/National Institutes of Health, Research Triangle Park, NC 27709, USA
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9
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Kurtz P, Jones AE, Tiwari B, Link N, Wylie A, Tracy C, Krämer H, Abrams JM. Drosophila p53 directs nonapoptotic programs in postmitotic tissue. Mol Biol Cell 2019; 30:1339-1351. [PMID: 30892991 PMCID: PMC6724604 DOI: 10.1091/mbc.e18-12-0791] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
TP53 is the most frequently mutated gene in human cancers, and despite intensive research efforts, genome-scale studies of p53 function in whole animal models are rare. The need for such in vivo studies is underscored by recent challenges to established paradigms, indicating that unappreciated p53 functions contribute to cancer prevention. Here we leveraged the Drosophila system to interrogate p53 function in a postmitotic context. In the developing embryo, p53 robustly activates important apoptotic genes in response to radiation-induced DNA damage. We recently showed that a p53 enhancer (p53RErpr) near the cell death gene reaper forms chromatin contacts and enables p53 target activation across long genomic distances. Interestingly, we found that this canonical p53 apoptotic program fails to activate in adult heads. Moreover, this failure to exhibit apoptotic responses was not associated with altered chromatin contacts. Instead, we determined that p53 does not occupy the p53RErpr enhancer in this postmitotic tissue as it does in embryos. Through comparative RNA-seq and chromatin immunoprecipitation-seq studies of developing and postmitotic tissues, we further determined that p53 regulates distinct transcriptional programs in adult heads, including DNA repair, metabolism, and proteolysis genes. Strikingly, in the postmitotic context, p53-binding landscapes were poorly correlated with nearby transcriptional effects, raising the possibility that p53 enhancers could be generally acting through long distances.
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Affiliation(s)
- Paula Kurtz
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Amanda E Jones
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Bhavana Tiwari
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Nichole Link
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030.,Howard Hughes Medical Institute, Baylor College of Medicine, Houston, TX 77030.,Jan and Dan Duncan Neurological Research Institute, Houston, TX 77030
| | - Annika Wylie
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Charles Tracy
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Helmut Krämer
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390.,Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - John M Abrams
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
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10
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Transposons, p53 and Genome Security. Trends Genet 2018; 34:846-855. [PMID: 30195581 DOI: 10.1016/j.tig.2018.08.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Revised: 07/31/2018] [Accepted: 08/07/2018] [Indexed: 12/16/2022]
Abstract
p53, the most commonly mutated tumor suppressor, is a transcription factor known to regulate proliferation, senescence, and apoptosis. Compelling studies have found that p53 may prevent oncogenesis through effectors that are unrelated to these canonical processes and recent findings have uncovered ancient roles for p53 in the containment of mobile elements. Together, these developments raise the possibility that some p53-driven cancers could result from unrestrained transposons. Here, we explore evidence linking conserved features of p53 biology to the control of transposons. We also show how p53-deficient cells can be exploited to probe the behavior of transposons and illustrate how unrestrained transposons incited by p53 loss might contribute to human malignancies.
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11
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Chen X, Guan H, Liu XD, Xie DF, Wang Y, Ma T, Huang B, Zhou PK. p53 positively regulates the expression of cancer stem cell marker CD133 in HCT116 colon cancer cells. Oncol Lett 2018; 16:431-438. [PMID: 29928431 DOI: 10.3892/ol.2018.8619] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2017] [Accepted: 11/16/2017] [Indexed: 02/06/2023] Open
Abstract
Colon cancer stem cells (CSCs), which are highly capable of self-renewal and proliferation, are involved in colon tumorigenesis and response to therapy. CD133 is considered the most robust surface marker for colorectal cancer stem cells. Although the TP53 gene is frequently mutated in colon cancer, it remains not fully understood whether and how tumor protein p53 (p53) is associated with CD133 expression in colon cancer cells. In the present study, the expression of the CSC biomarker CD133 was investigated in terms of p53 status in colorectal carcinoma HCT116 cells. p53 wild-type HCT116 (HCT116 p53+/+) and depleted HCT116 (HCT116 p53-/-) cells were used throughout this study. Cells carrying the CSC biomarkers CD133 and CD44 were examined by flow cytometry. A dual-luciferase reporter assay was employed to further confirm the transcriptional regulation of the CD133 promoter by p53. The results demonstrated that there was a significant difference in the % of CD133-positive cells between the HCT116 p53+/+ cell line (84.84±0.05%) and the HCT116 p53-/- cell line (4.13±0.02%). The mRNA expression levels of CD133 in HCT116 p53+/+ cells were also significantly higher compared with HCT116 p53-/- cells. Knockdown of p53 by specific small interfering RNA greatly reduced the expression of CD133 in HCT116 p53+/+ cells. Transcription factor binding site analysis indicated that there are several p53 binding elements in the CD133 promoter region. A dual-luciferase reporter assay further demonstrated the transcriptional activation of CD133 promoter by p53. In conclusion, these results suggest that p53 positively regulates the expression of CSC marker CD133 in the HCT116 human colon colorectal cancer cell line. p53 may be involved in the initiation and maintenance of colorectal cancer stem cells through regulating the expression of CD133.
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Affiliation(s)
- Xia Chen
- Institute for Environmental Medicine and Radiation Hygiene, School of Public Health, University of South China, Hengyang, Hunan 421001, P.R. China.,Department of Radiation Toxicology and Oncology, Beijing Key Laboratory for Radiobiology, Beijing Institute of Radiation Medicine, Beijing 100850, P.R. China
| | - Hua Guan
- Department of Radiation Toxicology and Oncology, Beijing Key Laboratory for Radiobiology, Beijing Institute of Radiation Medicine, Beijing 100850, P.R. China
| | - Xiao-Dan Liu
- Department of Radiation Toxicology and Oncology, Beijing Key Laboratory for Radiobiology, Beijing Institute of Radiation Medicine, Beijing 100850, P.R. China
| | - Da-Fei Xie
- Department of Radiation Toxicology and Oncology, Beijing Key Laboratory for Radiobiology, Beijing Institute of Radiation Medicine, Beijing 100850, P.R. China
| | - Yu Wang
- Department of Radiation Toxicology and Oncology, Beijing Key Laboratory for Radiobiology, Beijing Institute of Radiation Medicine, Beijing 100850, P.R. China
| | - Teng Ma
- Department of Radiation Toxicology and Oncology, Beijing Key Laboratory for Radiobiology, Beijing Institute of Radiation Medicine, Beijing 100850, P.R. China
| | - Bo Huang
- Institute for Environmental Medicine and Radiation Hygiene, School of Public Health, University of South China, Hengyang, Hunan 421001, P.R. China
| | - Ping-Kun Zhou
- Institute for Environmental Medicine and Radiation Hygiene, School of Public Health, University of South China, Hengyang, Hunan 421001, P.R. China.,Department of Radiation Toxicology and Oncology, Beijing Key Laboratory for Radiobiology, Beijing Institute of Radiation Medicine, Beijing 100850, P.R. China
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12
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Zerdoumi Y, Lanos R, Raad S, Flaman JM, Bougeard G, Frebourg T, Tournier I. Germline TP53 mutations result into a constitutive defect of p53 DNA binding and transcriptional response to DNA damage. Hum Mol Genet 2018; 26:2591-2602. [PMID: 28369373 PMCID: PMC5886078 DOI: 10.1093/hmg/ddx106] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Accepted: 03/13/2017] [Indexed: 01/13/2023] Open
Abstract
Li-Fraumeni Syndrome (LFS) results from heterozygous germline mutations of TP53, encoding a key transcriptional factor activated in response to DNA damage. We have recently shown, from a large LFS series, that dominant-negative missense mutations are the most clinically severe and, thanks to a new p53 functional assay in lymphocytes, that they alter the p53 transcriptional response to DNA damage more drastically than null mutations. In this study, we first confirmed this observation by performing the p53 functional assay in lymphocytes from 56 TP53 mutation carriers harbouring 35 distinct alterations. Then, to compare the impact of the different types of germline TP53 mutations on DNA binding, we performed chromatin immunoprecipitation-sequencing (ChIP-Seq) in lymphocytes exposed to doxorubicin. ChIP-Seq performed in wild-type TP53 control lymphocytes accurately mapped 1287 p53-binding sites. New p53-binding sites were validated using a functional assay in yeast. ChIP-Seq analysis of LFS lymphocytes carrying TP53 null mutations (p.P152Rfs*18 or complete deletion) or the low penetrant ‘Brazilian’ p.R337H mutation revealed a moderate decrease of p53-binding sites (949, 580 and 620, respectively) and of ChIP-Seq peak depths. In contrast, analysis of LFS lymphocytes with TP53 dominant-negative missense mutations p.R273H or p.R248W revealed only 310 and 143 p53-binding sites, respectively, and the depths of the corresponding peaks were drastically reduced. Altogether, our results show that TP53 mutation carriers exhibit a constitutive defect of the transcriptional response to DNA damage and that the clinical severity of TP53 dominant-negative missense mutations is explained by a massive and global alteration of p53 DNA binding.
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Affiliation(s)
- Yasmine Zerdoumi
- Normandie University, UNIROUEN, Inserm U1245 and Rouen University Hospital, Department of Genetics, F 76000, Normandy Centre for Genomic and Personalized Medicine, Rouen, France
| | - Raphaël Lanos
- Normandie University, UNIROUEN, Inserm U1245 and Rouen University Hospital, Department of Genetics, F 76000, Normandy Centre for Genomic and Personalized Medicine, Rouen, France
| | - Sabine Raad
- Normandie University, UNIROUEN, Inserm U1245 and Rouen University Hospital, Department of Genetics, F 76000, Normandy Centre for Genomic and Personalized Medicine, Rouen, France
| | - Jean-Michel Flaman
- Normandie University, UNIROUEN, Inserm U1245 and Rouen University Hospital, Department of Genetics, F 76000, Normandy Centre for Genomic and Personalized Medicine, Rouen, France
| | - Gaëlle Bougeard
- Normandie University, UNIROUEN, Inserm U1245 and Rouen University Hospital, Department of Genetics, F 76000, Normandy Centre for Genomic and Personalized Medicine, Rouen, France
| | - Thierry Frebourg
- Normandie University, UNIROUEN, Inserm U1245 and Rouen University Hospital, Department of Genetics, F 76000, Normandy Centre for Genomic and Personalized Medicine, Rouen, France
| | - Isabelle Tournier
- Normandie University, UNIROUEN, Inserm U1245 and Rouen University Hospital, Department of Genetics, F 76000, Normandy Centre for Genomic and Personalized Medicine, Rouen, France
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13
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Loss of p53-inducible long non-coding RNA LINC01021 increases chemosensitivity. Oncotarget 2017; 8:102783-102800. [PMID: 29262524 PMCID: PMC5732690 DOI: 10.18632/oncotarget.22245] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Accepted: 10/02/2017] [Indexed: 12/19/2022] Open
Abstract
We have previously identified the long non-coding RNA LINC01021 as a direct p53 target (Hünten et al. Mol Cell Proteomics. 2015; 14:2609-2629). Here, we show that LINC01021 is up-regulated in colorectal cancer (CRC) cell lines upon various p53-activating treatments. The LINC01021 promoter and the p53 binding site lie within a MER61C LTR, which originated from insertion of endogenous retrovirus 1 (ERV1) sequences. Deletion of this MER61C element by a CRISPR/Cas9 approach, as well as siRNA-mediated knockdown of LINC01021 RNA significantly enhanced the sensitivity of the CRC cell line HCT116 towards the chemotherapeutic drugs doxorubicin and 5-FU, suggesting that LINC01021 is an integral part of the p53-mediated response to DNA damage. Inactivation of LINC01021 and also its ectopic expression did not affect p53 protein expression and transcriptional activity, implying that LINC01021 does not feedback to p53. Furthermore, in CRC patient samples LINC01021 expression positively correlated with a wild-type p53-associated gene expression signature. LINC01021 expression was increased in primary colorectal tumors and displayed a bimodal distribution that was particularly pronounced in the mesenchymal CMS4 consensus molecular subtype of CRCs. CMS4 tumors with low LINC01021 expression were associated with poor patient survival. Our results suggest that the genomic redistribution of ERV1-derived p53 response elements and generation of novel p53-inducible lncRNA-encoding genes was selected for during primate evolution as integral part of the cellular response to various forms of genotoxic stress.
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14
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Bao F, LoVerso PR, Fisk JN, Zhurkin VB, Cui F. p53 binding sites in normal and cancer cells are characterized by distinct chromatin context. Cell Cycle 2017; 16:2073-2085. [PMID: 28820292 PMCID: PMC5731425 DOI: 10.1080/15384101.2017.1361064] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The tumor suppressor protein p53 interacts with DNA in a sequence-dependent manner. Thousands of p53 binding sites have been mapped genome-wide in normal and cancer cells. However, the way p53 selectively binds its cognate sites in different types of cells is not fully understood. Here, we performed a comprehensive analysis of 25 published p53 cistromes and identified 3,551 and 6,039 ‘high-confidence’ binding sites in normal and cancer cells, respectively. Our analysis revealed 2 distinct epigenetic features underlying p53-DNA interactions in vivo. First, p53 binding sites are associated with transcriptionally active histone marks (H3K4me3 and H3K36me3) in normal-cell chromatin, but with repressive histone marks (H3K27me3) in cancer-cell chromatin. Second, p53 binding sites in cancer cells are characterized by a lower level of DNA methylation than their counterparts in normal cells, probably related to global hypomethylation in cancers. Intriguingly, regardless of the cell type, p53 sites are highly enriched in the endogenous retroviral elements of the ERV1 family, highlighting the importance of this repeat family in shaping the transcriptional network of p53. Moreover, the p53 sites exhibit an unusual combination of chromatin patterns: high nucleosome occupancy and, at the same time, high sensitivity to DNase I. Our results suggest that p53 can access its target sites in a chromatin environment that is non-permissive to most DNA-binding transcription factors, which may allow p53 to act as a pioneer transcription factor in the context of chromatin.
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Affiliation(s)
- Feifei Bao
- a Thomas H. Gosnell School of Life Sciences , Rochester Institute of Technology , Rochester , NY , USA
| | - Peter R LoVerso
- b Laboratory of Cell Biology , National Cancer Institute , Bethesda , MD , USA
| | - Jeffrey N Fisk
- a Thomas H. Gosnell School of Life Sciences , Rochester Institute of Technology , Rochester , NY , USA
| | - Victor B Zhurkin
- b Laboratory of Cell Biology , National Cancer Institute , Bethesda , MD , USA
| | - Feng Cui
- a Thomas H. Gosnell School of Life Sciences , Rochester Institute of Technology , Rochester , NY , USA
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15
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Zhang Y, Kang R, Liu W, Yang Y, Ding R, Huang Q, Meng J, Xiong L, Guo Z. Identification and Analysis of P53-Mediated Competing Endogenous RNA Network in Human Hepatocellular Carcinoma. Int J Biol Sci 2017; 13:1213-1221. [PMID: 29104512 PMCID: PMC5666336 DOI: 10.7150/ijbs.21502] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Accepted: 07/30/2017] [Indexed: 12/22/2022] Open
Abstract
Recent studies have indicated that long non-coding RNAs (lncRNAs) and mRNA function as competing endogenous RNAs (ceRNAs) that compete to bind to shared microRNA (miRNA) recognition elements (MREs) to perform specific biological functions during tumorigenesis. The tumor suppressor p53 is a master regulator of cancer-related biological processes by acting as a transcription factor to regulate target genes including miRNA and lncRNA. However, the mechanism in human hepatocellular carcinoma and whether p53-mediated RNA targets could form ceRNA network remain unclear. Here, we identified a series of differential expressed miRNAs, lncRNA and mRNA which were potentially regulated by p53 using RNA sequencing in HepG2. Genomic characteristics comparative analysis showed significant differences between mRNAs and lncRNAs. By integrating experimentally confirmed Ago2 and p53 binding sites, we constructed a highly reliable p53-mediated ceRNA network using hypergeometric test. The KEGG pathway enrichment analysis showed that the ceRNA network highly enriched in the cancer or p53-associated signaling pathways. Finally, using betweenness centrality analysis, we identified five master miRNAs (hsa-miR-3620-5p, hsa-miR-3613-3p, hsa-miR-6881-3p, hsa-miR-6087 and hsa-miR-18a-3p) that regulated most of the target RNAs, suggesting these miRNAs play central roles in the whole p53-mediated ceRNAs network. Taken together, our results provide a new regulatory mechanism of p53 networks for future studies in cancer therapeutics.
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Affiliation(s)
- Yiming Zhang
- School of Life Sciences and Bioengineering, Southwest Jiaotong University
| | - Ran Kang
- School of Life Sciences and Bioengineering, Southwest Jiaotong University
| | - Wenrong Liu
- School of Life Sciences and Bioengineering, Southwest Jiaotong University
| | - Yalan Yang
- School of Life Sciences and Bioengineering, Southwest Jiaotong University
| | - Ruofan Ding
- School of Life Sciences and Bioengineering, Southwest Jiaotong University
| | - Qingqing Huang
- School of Life Sciences and Bioengineering, Southwest Jiaotong University
| | - Junhua Meng
- School of Life Sciences and Bioengineering, Southwest Jiaotong University
| | - Lili Xiong
- School of Life Sciences and Bioengineering, Southwest Jiaotong University
| | - Zhiyun Guo
- School of Life Sciences and Bioengineering, Southwest Jiaotong University
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16
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Abstract
The p53 tumor suppressor has been studied for decades, and still there are many questions left unanswered. In this review, we first describe the current understanding of the wild-type p53 functions that determine cell survival or death, and regulation of the protein, with a particular focus on the negative regulators, the murine double minute family of proteins. We also summarize tissue-, stress-, and age-specific p53 activities and the potential underlying mechanisms. Among all p53 gene alterations identified in human cancers, p53 missense mutations predominate, suggesting an inherent biological advantage. Numerous gain-of-function activities of mutant p53 in different model systems and contexts have been identified. The emerging theme is that mutant p53, which retains a potent transcriptional activation domain, also retains the ability to modify gene transcription, albeit indirectly. Lastly, because mutant p53 stability is necessary for its gain of function, we summarize the mechanisms through which mutant p53 is specifically stabilized. A deeper understanding of the multiple pathways that impinge upon wild-type and mutant p53 activities and how these, in turn, regulate cell behavior will help identify vulnerabilities and therapeutic opportunities.
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Affiliation(s)
- Yun Zhang
- Department of Genetics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030
| | - Guillermina Lozano
- Department of Genetics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030
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17
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Millau JF, Wijchers P, Gaudreau L. High-Resolution 4C Reveals Rapid p53-Dependent Chromatin Reorganization of the CDKN1A Locus in Response to Stress. PLoS One 2016; 11:e0163885. [PMID: 27741251 PMCID: PMC5065170 DOI: 10.1371/journal.pone.0163885] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Accepted: 09/15/2016] [Indexed: 01/09/2023] Open
Abstract
A regulatory program involving hundreds of genes is coordinated by p53 to prevent carcinogenesis in response to stress. Given the importance of chromatin loops in gene regulation, we investigated whether DNA interactions participate in the p53 stress response. To shed light on this issue, we measured the binding dynamics of cohesin in response to stress. We reveal that cohesin is remodeled at specific loci during the stress response and that its binding within genes negatively correlates with transcription. At p53 target genes, stress-induced eviction of cohesin from gene bodies is concomitant to spatial reorganization of loci through the disruption of functional chromatin loops. These findings demonstrate that chromatin loops can be remodeled upon stress and contribute to the p53-driven stress response. Additionally, we also propose a mechanism whereby transcription-coupled eviction of cohesin from CDKN1A might act as a molecular switch to control spatial interactions between regulatory elements.
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Affiliation(s)
- Jean-François Millau
- Départment de Biologie, Faculté des Sciences, Université de Sherbrooke, Sherbrooke, QC J1K 2R1, Canada
| | - Patrick Wijchers
- Hubrecht Institute-KNAW and University Medical Center Utrecht, Uppsalalaan 8, 3584 CT Utrecht, the Netherlands
| | - Luc Gaudreau
- Départment de Biologie, Faculté des Sciences, Université de Sherbrooke, Sherbrooke, QC J1K 2R1, Canada
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18
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Multiplex enhancer-reporter assays uncover unsophisticated TP53 enhancer logic. Genome Res 2016; 26:882-95. [PMID: 27197205 PMCID: PMC4937571 DOI: 10.1101/gr.204149.116] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Accepted: 05/17/2016] [Indexed: 12/11/2022]
Abstract
Transcription factors regulate their target genes by binding to regulatory regions in the genome. Although the binding preferences of TP53 are known, it remains unclear what distinguishes functional enhancers from nonfunctional binding. In addition, the genome is scattered with recognition sequences that remain unoccupied. Using two complementary techniques of multiplex enhancer-reporter assays, we discovered that functional enhancers could be discriminated from nonfunctional binding events by the occurrence of a single TP53 canonical motif. By combining machine learning with a meta-analysis of TP53 ChIP-seq data sets, we identified a core set of more than 1000 responsive enhancers in the human genome. This TP53 cistrome is invariably used between cell types and experimental conditions, whereas differences among experiments can be attributed to indirect nonfunctional binding events. Our data suggest that TP53 enhancers represent a class of unsophisticated cell-autonomous enhancers containing a single TP53 binding site, distinct from complex developmental enhancers that integrate signals from multiple transcription factors.
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19
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Ye C, Ji G, Liang C. detectMITE: A novel approach to detect miniature inverted repeat transposable elements in genomes. Sci Rep 2016; 6:19688. [PMID: 26795595 PMCID: PMC4726161 DOI: 10.1038/srep19688] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Accepted: 12/14/2015] [Indexed: 12/27/2022] Open
Abstract
Miniature inverted repeat transposable elements (MITEs) are prevalent in eukaryotic genomes, including plants and animals. Classified as a type of non-autonomous DNA transposable elements, they play important roles in genome organization and evolution. Comprehensive and accurate genome-wide detection of MITEs in various eukaryotic genomes can improve our understanding of their origins, transposition processes, regulatory mechanisms, and biological relevance with regard to gene structures, expression, and regulation. In this paper, we present a new MATLAB-based program called detectMITE that employs a novel numeric calculation algorithm to replace conventional string matching algorithms in MITE detection, adopts the Lempel-Ziv complexity algorithm to filter out MITE candidates with low complexity, and utilizes the powerful clustering program CD-HIT to cluster similar MITEs into MITE families. Using the rice genome as test data, we found that detectMITE can more accurately, comprehensively, and efficiently detect MITEs on a genome-wide scale than other popular MITE detection tools. Through comparison with the potential MITEs annotated in Repbase, the widely used eukaryotic repeat database, detectMITE has been shown to find known and novel MITEs with a complete structure and full-length copies in the genome. detectMITE is an open source tool (https://sourceforge.net/projects/detectmite).
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Affiliation(s)
- Congting Ye
- Department of Automation, Xiamen University, Xiamen, Fujian 361005, China.,Department of Biology, Miami University, Oxford, Ohio 45056, USA
| | - Guoli Ji
- Department of Automation, Xiamen University, Xiamen, Fujian 361005, China.,Innovation Center for Cell Biology, Xiamen University, Xiamen, Fujian 361102, China
| | - Chun Liang
- Department of Biology, Miami University, Oxford, Ohio 45056, USA
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20
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Botcheva K. p53 binding to human genome: crowd control navigation in chromatin context. Front Genet 2014; 5:447. [PMID: 25566329 PMCID: PMC4273661 DOI: 10.3389/fgene.2014.00447] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2014] [Accepted: 12/05/2014] [Indexed: 11/22/2022] Open
Abstract
p53 is the most studied human protein because of its role in maintaining genomic stability. Binding to genomic targets is essential for transcription-dependent p53 tumor suppression, but how p53 selects targets remains unclear. Here, the impact of chromatin context on p53 genome-wide binding and targets selection is discussed. It is proposed that p53 genomic binding serves not only to regulate transcription, but to sense epigenomic changes threatening the genomic integrity. The problem of p53 navigating the human genome is discussed with respect to the degenerate p53 binding motif. This discussion relates to the fundamental problem of DNA binding factors navigating large genomes in search for cognate binding sites.
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Affiliation(s)
- Krassimira Botcheva
- Cell and Molecular Biology Department, Life Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, CA, USA
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