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Acosta J, Li Q, Freeburg NF, Murali N, Indeglia A, Grothusen GP, Cicchini M, Mai H, Gladstein AC, Adler KM, Doerig KR, Li J, Ruiz-Torres M, Manning KL, Stanger BZ, Busino L, Murphy M, Wan L, Feldser DM. p53 restoration in small cell lung cancer identifies a latent cyclophilin-dependent necrosis mechanism. Nat Commun 2023; 14:4403. [PMID: 37479684 PMCID: PMC10362054 DOI: 10.1038/s41467-023-40161-9] [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: 08/12/2022] [Accepted: 07/12/2023] [Indexed: 07/23/2023] Open
Abstract
The p53 tumor suppressor regulates multiple context-dependent tumor suppressive programs. Although p53 is mutated in ~90% of small cell lung cancer (SCLC) tumors, how p53 mediates tumor suppression in this context is unknown. Here, using a mouse model of SCLC in which endogenous p53 expression can be conditionally and temporally regulated, we show that SCLC tumors maintain a requirement for p53 inactivation. However, we identify tumor subtype heterogeneity between SCLC tumors such that p53 reactivation induces senescence in a subset of tumors, while in others, p53 induces necrosis. We pinpoint cyclophilins as critical determinants of a p53-induced transcriptional program that is specific to SCLC tumors and cell lines poised to undergo p53-mediated necrosis. Importantly, inhibition of cyclophilin isomerase activity, or genetic ablation of specific cyclophilin genes, suppresses p53-mediated necrosis by limiting p53 transcriptional output without impacting p53 chromatin binding. Our study demonstrates that intertumoral heterogeneity in SCLC influences the biological response to p53 restoration, describes a cyclophilin-dependent mechanism of p53-regulated cell death, and uncovers putative mechanisms for the treatment of this most-recalcitrant tumor type.
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Affiliation(s)
- Jonuelle Acosta
- Department of Cancer Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Cell and Molecular Biology Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Qinglan Li
- Department of Cancer Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Nelson F Freeburg
- Department of Cancer Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Cell and Molecular Biology Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Nivitha Murali
- Department of Cancer Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Alexandra Indeglia
- Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Grant P Grothusen
- Department of Cancer Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Cell and Molecular Biology Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Michelle Cicchini
- Department of Cancer Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Hung Mai
- Department of Cancer Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Amy C Gladstein
- Department of Cancer Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Cell and Molecular Biology Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Keren M Adler
- Department of Cancer Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Cell and Molecular Biology Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Katherine R Doerig
- Department of Cancer Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Cell and Molecular Biology Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Jinyang Li
- Department of Cancer Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Miguel Ruiz-Torres
- Department of Cancer Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Kimberly L Manning
- Department of Cancer Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Ben Z Stanger
- Cell and Molecular Biology Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Abramson Family Cancer Research Institute, University of Pennsylvania, Philadelphia, PA, USA
| | - Luca Busino
- Department of Cancer Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Cell and Molecular Biology Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Abramson Family Cancer Research Institute, University of Pennsylvania, Philadelphia, PA, USA
| | - Maureen Murphy
- Cell and Molecular Biology Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Program in Molecular and Cellular Oncogenesis, The Wistar Institute, Philadelphia, PA, USA
| | - Liling Wan
- Department of Cancer Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Cell and Molecular Biology Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Abramson Family Cancer Research Institute, University of Pennsylvania, Philadelphia, PA, USA
| | - David M Feldser
- Department of Cancer Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
- Cell and Molecular Biology Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
- Abramson Family Cancer Research Institute, University of Pennsylvania, Philadelphia, PA, USA.
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Haronikova L, Bonczek O, Zatloukalova P, Kokas-Zavadil F, Kucerikova M, Coates PJ, Fahraeus R, Vojtesek B. Resistance mechanisms to inhibitors of p53-MDM2 interactions in cancer therapy: can we overcome them? Cell Mol Biol Lett 2021; 26:53. [PMID: 34911439 PMCID: PMC8903693 DOI: 10.1186/s11658-021-00293-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Accepted: 11/05/2021] [Indexed: 12/13/2022] Open
Abstract
Since the discovery of the first MDM2 inhibitors, we have gained deeper insights into the cellular roles of MDM2 and p53. In this review, we focus on MDM2 inhibitors that bind to the p53-binding domain of MDM2 and aim to disrupt the binding of MDM2 to p53. We describe the basic mechanism of action of these MDM2 inhibitors, such as nutlin-3a, summarise the determinants of sensitivity to MDM2 inhibition from p53-dependent and p53-independent points of view and discuss the problems with innate and acquired resistance to MDM2 inhibition. Despite progress in MDM2 inhibitor design and ongoing clinical trials, their broad use in cancer treatment is not fulfilling expectations in heterogenous human cancers. We assess the MDM2 inhibitor types in clinical trials and provide an overview of possible sources of resistance to MDM2 inhibition, underlining the need for patient stratification based on these aspects to gain better clinical responses, including the use of combination therapies for personalised medicine.
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Affiliation(s)
- Lucia Haronikova
- RECAMO, Masaryk Memorial Cancer Institute, Zluty kopec 7, 656 53, Brno, Czech Republic.
| | - Ondrej Bonczek
- RECAMO, Masaryk Memorial Cancer Institute, Zluty kopec 7, 656 53, Brno, Czech Republic
- Department of Medical Biosciences, Umea University, 901 87, Umea, Vasterbotten, Sweden
| | - Pavlina Zatloukalova
- RECAMO, Masaryk Memorial Cancer Institute, Zluty kopec 7, 656 53, Brno, Czech Republic
| | - Filip Kokas-Zavadil
- RECAMO, Masaryk Memorial Cancer Institute, Zluty kopec 7, 656 53, Brno, Czech Republic
| | - Martina Kucerikova
- RECAMO, Masaryk Memorial Cancer Institute, Zluty kopec 7, 656 53, Brno, Czech Republic
- National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic
| | - Philip J Coates
- RECAMO, Masaryk Memorial Cancer Institute, Zluty kopec 7, 656 53, Brno, Czech Republic
| | - Robin Fahraeus
- RECAMO, Masaryk Memorial Cancer Institute, Zluty kopec 7, 656 53, Brno, Czech Republic
- Department of Medical Biosciences, Umea University, 901 87, Umea, Vasterbotten, Sweden
- Inserm UMRS1131, Institut de Génétique Moléculaire, Université Paris 7, Hôpital St. Louis, 75010, Paris, France
| | - Borivoj Vojtesek
- RECAMO, Masaryk Memorial Cancer Institute, Zluty kopec 7, 656 53, Brno, Czech Republic.
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3
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Grow EJ, Weaver BD, Smith CM, Guo J, Stein P, Shadle SC, Hendrickson PG, Johnson NE, Butterfield RJ, Menafra R, Kloet SL, van der Maarel SM, Williams CJ, Cairns BR. p53 convergently activates Dux/DUX4 in embryonic stem cells and in facioscapulohumeral muscular dystrophy cell models. Nat Genet 2021; 53:1207-1220. [PMID: 34267371 PMCID: PMC8513633 DOI: 10.1038/s41588-021-00893-0] [Citation(s) in RCA: 46] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Accepted: 06/01/2021] [Indexed: 12/21/2022]
Abstract
In mammalian embryos, proper zygotic genome activation (ZGA) underlies totipotent development. Double homeobox (DUX)-family factors participate in ZGA, and mouse Dux is required for forming cultured two-cell (2C)-like cells. Remarkably, in mouse embryonic stem cells, Dux is activated by the tumor suppressor p53, and Dux expression promotes differentiation into expanded-fate cell types. Long-read sequencing and assembly of the mouse Dux locus reveals its complex chromatin regulation including putative positive and negative feedback loops. We show that the p53-DUX/DUX4 regulatory axis is conserved in humans. Furthermore, we demonstrate that cells derived from patients with facioscapulohumeral muscular dystrophy (FSHD) activate human DUX4 during p53 signaling via a p53-binding site in a primate-specific subtelomeric long terminal repeat (LTR)10C element. In summary, our work shows that p53 activation convergently evolved to couple p53 to Dux/DUX4 activation in embryonic stem cells, embryos and cells from patients with FSHD, potentially uniting the developmental and disease regulation of DUX-family factors and identifying evidence-based therapeutic opportunities for FSHD.
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Affiliation(s)
- Edward J Grow
- Howard Hughes Medical Institute, Department of Oncological Sciences and Huntsman Cancer Institute, University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Bradley D Weaver
- Howard Hughes Medical Institute, Department of Oncological Sciences and Huntsman Cancer Institute, University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Christina M Smith
- Howard Hughes Medical Institute, Department of Oncological Sciences and Huntsman Cancer Institute, University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Jingtao Guo
- Howard Hughes Medical Institute, Department of Oncological Sciences and Huntsman Cancer Institute, University of Utah School of Medicine, Salt Lake City, UT, USA
- Division of Urology, Department of Surgery, University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Paula Stein
- Reproductive and Developmental Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, USA
| | - Sean C Shadle
- Howard Hughes Medical Institute, Department of Oncological Sciences and Huntsman Cancer Institute, University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Peter G Hendrickson
- Howard Hughes Medical Institute, Department of Oncological Sciences and Huntsman Cancer Institute, University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Nicholas E Johnson
- Department of Neurology, University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Russell J Butterfield
- Department of Neurology, University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Roberta Menafra
- Leiden Genome Technology Center, Department of Human Genetics, Leiden University Medical Center, Leiden, the Netherlands
| | - Susan L Kloet
- Leiden Genome Technology Center, Department of Human Genetics, Leiden University Medical Center, Leiden, the Netherlands
| | | | - Carmen J Williams
- Reproductive and Developmental Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, USA
| | - Bradley R Cairns
- Howard Hughes Medical Institute, Department of Oncological Sciences and Huntsman Cancer Institute, University of Utah School of Medicine, Salt Lake City, UT, USA.
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The p53 transcriptional response across tumor types reveals core and senescence-specific signatures modulated by long noncoding RNAs. Proc Natl Acad Sci U S A 2021; 118:2025539118. [PMID: 34326251 PMCID: PMC8346867 DOI: 10.1073/pnas.2025539118] [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] [Indexed: 12/31/2022] Open
Abstract
The work by Tesfaye and colleagues defines universal and tumor type–specific features of the p53 tumor suppressor transcriptional network. This study determines a “core” signature of the p53 response across different oncogenic contexts, which defines a universal set of p53 target genes. In addition, this study clarifies the basis for outcome specificity downstream of p53 activation in different oncogenic contexts. We observe that while apoptosis in lymphoma cells is not primarily determined by p53’s transcriptional activity, p53 indirectly promotes senescence in lung adenocarcinoma and sarcoma cells by activating the cis-regulatory long noncoding RNA Pvt1b, which represses Myc levels and its proliferative function. The p53 pathway is a universal tumor suppressor mechanism that limits tumor progression by triggering apoptosis or permanent cell cycle arrest, called senescence. In recent years, efforts to reactivate p53 function in cancer have proven to be a successful therapeutic strategy in murine models and have gained traction with the development of a range of small molecules targeting mutant p53. However, knowledge of the downstream mediators of p53 reactivation in different oncogenic contexts has been limited. Here, we utilized a panel of murine cancer cell lines from three distinct tumor types susceptible to alternative outcomes following p53 restoration to define unique and shared p53 transcriptional signatures. While we found that the majority of p53-bound sites and p53-responsive transcripts are tumor-type specific, analysis of shared targets identified a core signature of genes activated by p53 across all contexts. Furthermore, we identified repression of E2F and Myc target genes as a key feature of senescence. Characterization of p53-induced transcripts revealed core and senescence-specific long noncoding RNAs (lncRNAs) that are predominantly chromatin associated and whose production is coupled to cis-regulatory activities. Functional investigation of the contributions of p53-induced lncRNAs to p53-dependent outcomes highlighted Pvt1b, the p53-dependent isoform of Pvt1, as a mediator of p53-dependent senescence via Myc repression. Inhibition of Pvt1b led to decreased activation of senescence markers and increased levels of markers of proliferation. These findings shed light on the core and outcome-specific p53 restoration signatures across different oncogenic contexts and underscore the key role of the p53-Pvt1b-Myc regulatory axis in mediating proliferative arrest.
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p53 mediates target gene association with nuclear speckles for amplified RNA expression. Mol Cell 2021; 81:1666-1681.e6. [PMID: 33823140 DOI: 10.1016/j.molcel.2021.03.006] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 01/05/2021] [Accepted: 03/03/2021] [Indexed: 01/01/2023]
Abstract
Nuclear speckles are prominent nuclear bodies that contain proteins and RNA involved in gene expression. Although links between nuclear speckles and gene activation are emerging, the mechanisms regulating association of genes with speckles are unclear. We find that speckle association of p53 target genes is driven by the p53 transcription factor. Focusing on p21, a key p53 target, we demonstrate that speckle association boosts expression by elevating nascent RNA amounts. p53-regulated speckle association did not depend on p53 transactivation functions but required an intact proline-rich domain and direct DNA binding, providing mechanisms within p53 for regulating gene-speckle association. Beyond p21, a substantial subset of p53 targets have p53-regulated speckle association. Strikingly, speckle-associating p53 targets are more robustly activated and occupy a distinct niche of p53 biology compared with non-speckle-associating p53 targets. Together, our findings illuminate regulated speckle association as a mechanism used by a transcription factor to boost gene expression.
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Chappell GA, Heintz MM, Haws LC. Transcriptomic analyses of livers from mice exposed to 1,4-dioxane for up to 90 days to assess potential mode(s) of action underlying liver tumor development. Curr Res Toxicol 2021; 2:30-41. [PMID: 34345848 PMCID: PMC8320614 DOI: 10.1016/j.crtox.2021.01.003] [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: 10/27/2020] [Revised: 01/06/2021] [Accepted: 01/07/2021] [Indexed: 12/11/2022] Open
Abstract
1,4-Dioxane is a volatile organic compound with industrial and commercial applications as a solvent and in the manufacture of other chemicals. 1,4-Dioxane has been demonstrated to induce liver tumors in chronic rodent bioassays conducted at very high doses. The available evidence for 1,4-dioxane-induced liver tumors in rodents aligns with a threshold-dependent mode of action (MOA), with the underlying mechanism being less clear in the mouse than in rats. To gain a better understanding of the underlying molecular mechanisms related to liver tumor development in mice orally exposed to 1,4-dioxane, transcriptomics analysis was conducted on liver tissue collected from a 90-day drinking water study in female B6D2F1/Crl mice (Lafranconi et al., 2020). Using tissue samples from female mice exposed to 1,4-dioxane in the drinking water at concentrations of 0, 40, 200, 600, 2,000 or 6,000 ppm for 7, 28, and 90 days, transcriptomic analyses demonstrate minimal treatment effects on global gene expression at concentrations below 600 ppm. At higher concentrations, genes involved in phase II metabolism and mitotic cell cycle checkpoints were significantly upregulated. There was an overall lack of enrichment of genes related to DNA damage response. The increase in mitotic signaling is most prevalent in the livers of mice exposed to 1,4-dioxane at the highest concentrations for 90 days. This finding aligns with phenotypic changes reported by Lafranconi et al. (2020) after 90-days of exposure to 6,000 ppm 1,4-dioxane in the same tissues. The transcriptomics analysis further supports overarching study findings demonstrating a non-mutagenic, threshold-based, mitogenic MOA for 1,4-dioxane-induced liver tumors.
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Affiliation(s)
- G A Chappell
- ToxStrategies, Inc., Asheville, NC, United States
| | - M M Heintz
- ToxStrategies, Inc., Asheville, NC, United States
| | - L C Haws
- ToxStrategies, Inc., Austin, TX, United States
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Celardo I, Melino G, Amelio I. Commensal microbes and p53 in cancer progression. Biol Direct 2020; 15:25. [PMID: 33213502 PMCID: PMC7678320 DOI: 10.1186/s13062-020-00281-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Accepted: 11/12/2020] [Indexed: 02/07/2023] Open
Abstract
Aetiogenesis of cancer has not been fully determined. Recent advances have clearly defined a role for microenvironmental factors in cancer progression and initiation; in this context, microbiome has recently emerged with a number of reported correlative and causative links implicating alterations of commensal microbes in tumorigenesis. Bacteria appear to have the potential to directly alter physiological pathways of host cells and in specific circumstances, such as the mutation of the tumour suppressive factor p53, they can also directly switch the function of a gene from oncosuppressive to oncogenic. In this minireview, we report a number of examples on how commensal microbes alter the host cell biology, affecting the oncogenic process. We then discuss more in detail how interaction with the gut microbiome can affect the function of p53 mutant in the intestinal tumorigenesis.
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Affiliation(s)
- Ivana Celardo
- MRC Toxicology Unit, University of Cambridge, Cambridge, UK
| | - Gerry Melino
- Department of Experimental Medicine, TOR, University of Rome Tor Vergata, Rome, Italy
| | - Ivano Amelio
- Department of Experimental Medicine, TOR, University of Rome Tor Vergata, Rome, Italy.
- School of Life Sciences, University of Nottingham, Nottingham, UK.
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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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Hafner A, Kublo L, Tsabar M, Lahav G, Stewart-Ornstein J. Identification of universal and cell-type specific p53 DNA binding. BMC Mol Cell Biol 2020; 21:5. [PMID: 32070277 PMCID: PMC7027055 DOI: 10.1186/s12860-020-00251-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Accepted: 02/11/2020] [Indexed: 01/09/2023] Open
Abstract
Background The tumor suppressor p53 is a major regulator of the DNA damage response and has been suggested to selectively bind and activate cell-type specific gene expression programs. However recent studies and meta-analyses of genomic data propose largely uniform, and condition independent p53 binding and thus question the selective and cell-type dependent function of p53. Results To systematically assess the cell-type specificity of p53, we measured its association with DNA in 12 p53 wild-type cancer cell lines, from a range of epithelial linages, in response to ionizing radiation. We found that the majority of bound sites were occupied across all cell lines, however we also identified a subset of binding sites that were specific to one or a few cell lines. Unlike the shared p53-bound genome, which was not dependent on chromatin accessibility, the association of p53 with these atypical binding sites was well explained by chromatin accessibility and could be modulated by forcing cell state changes such as the epithelial-to-mesenchymal transition. Conclusions Our study reconciles previous conflicting views in the p53 field, by demonstrating that although the majority of p53 DNA binding is conserved across cell types, there is a small set of cell line specific binding sites that depend on cell state.
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Affiliation(s)
- Antonina Hafner
- Department of Systems Biology, Harvard Medical School, Boston, MA, 02115, USA. .,Department of Developmental Biology, Stanford University, Stanford, CA, 94305, USA.
| | - Lyubov Kublo
- University of Pittsburgh Medical Center (UPMC) Hillman Cancer Center, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213, USA
| | - Michael Tsabar
- Department of Systems Biology, Harvard Medical School, Boston, MA, 02115, USA
| | - Galit Lahav
- Department of Systems Biology, Harvard Medical School, Boston, MA, 02115, USA
| | - Jacob Stewart-Ornstein
- University of Pittsburgh Medical Center (UPMC) Hillman Cancer Center, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213, USA.,Department of Computational and Systems Biology, University of Pittsburgh Medical School, Pittsburgh, PA, 15260, USA
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10
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Kocik J, Machula M, Wisniewska A, Surmiak E, Holak TA, Skalniak L. Helping the Released Guardian: Drug Combinations for Supporting the Anticancer Activity of HDM2 (MDM2) Antagonists. Cancers (Basel) 2019; 11:cancers11071014. [PMID: 31331108 PMCID: PMC6678622 DOI: 10.3390/cancers11071014] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2019] [Revised: 07/13/2019] [Accepted: 07/16/2019] [Indexed: 01/22/2023] Open
Abstract
The protein p53, known as the “Guardian of the Genome”, plays an important role in maintaining DNA integrity, providing protection against cancer-promoting mutations. Dysfunction of p53 is observed in almost every cancer, with 50% of cases bearing loss-of-function mutations/deletions in the TP53 gene. In the remaining 50% of cases the overexpression of HDM2 (mouse double minute 2, human homolog) protein, which is a natural inhibitor of p53, is the most common way of keeping p53 inactive. Disruption of HDM2-p53 interaction with the use of HDM2 antagonists leads to the release of p53 and expression of its target genes, engaged in the induction of cell cycle arrest, DNA repair, senescence, and apoptosis. The induction of apoptosis, however, is restricted to only a handful of p53wt cells, and, generally, cancer cells treated with HDM2 antagonists are not efficiently eliminated. For this reason, HDM2 antagonists were tested in combinations with multiple other therapeutics in a search for synergy that would enhance the cancer eradication. This manuscript aims at reviewing the recent progress in developing strategies of combined cancer treatment with the use of HDM2 antagonists.
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Affiliation(s)
- Justyna Kocik
- Department of Organic Chemistry, Faculty of Chemistry, Jagiellonian University, ul. Gronostajowa 2, 30-387 Krakow, Poland
| | - Monika Machula
- Department of Organic Chemistry, Faculty of Chemistry, Jagiellonian University, ul. Gronostajowa 2, 30-387 Krakow, Poland
| | - Aneta Wisniewska
- Department of Organic Chemistry, Faculty of Chemistry, Jagiellonian University, ul. Gronostajowa 2, 30-387 Krakow, Poland
| | - Ewa Surmiak
- Department of Organic Chemistry, Faculty of Chemistry, Jagiellonian University, ul. Gronostajowa 2, 30-387 Krakow, Poland
| | - Tad A Holak
- Department of Organic Chemistry, Faculty of Chemistry, Jagiellonian University, ul. Gronostajowa 2, 30-387 Krakow, Poland
| | - Lukasz Skalniak
- Department of Organic Chemistry, Faculty of Chemistry, Jagiellonian University, ul. Gronostajowa 2, 30-387 Krakow, Poland.
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