1
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Bevill SM, Casaní-Galdón S, El Farran CA, Cytrynbaum EG, Macias KA, Oldeman SE, Oliveira KJ, Moore MM, Hegazi E, Adriaens C, Najm FJ, Demetri GD, Cohen S, Mullen JT, Riggi N, Johnstone SE, Bernstein BE. Impact of supraphysiologic MDM2 expression on chromatin networks and therapeutic responses in sarcoma. CELL GENOMICS 2023; 3:100321. [PMID: 37492096 PMCID: PMC10363746 DOI: 10.1016/j.xgen.2023.100321] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Revised: 03/09/2023] [Accepted: 04/14/2023] [Indexed: 07/27/2023]
Abstract
Amplification of MDM2 on supernumerary chromosomes is a common mechanism of P53 inactivation across tumors. Here, we investigated the impact of MDM2 overexpression on chromatin, gene expression, and cellular phenotypes in liposarcoma. Three independent regulatory circuits predominate in aggressive, dedifferentiated tumors. RUNX and AP-1 family transcription factors bind mesenchymal gene enhancers. P53 and MDM2 co-occupy enhancers and promoters associated with P53 signaling. When highly expressed, MDM2 also binds thousands of P53-independent growth and stress response genes, whose promoters engage in multi-way topological interactions. Overexpressed MDM2 concentrates within nuclear foci that co-localize with PML and YY1 and could also contribute to P53-independent phenotypes associated with supraphysiologic MDM2. Importantly, we observe striking cell-to-cell variability in MDM2 copy number and expression in tumors and models. Whereas liposarcoma cells are generally sensitive to MDM2 inhibitors and their combination with pro-apoptotic drugs, MDM2-high cells tolerate them and may underlie the poor clinical efficacy of these agents.
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Affiliation(s)
- Samantha M. Bevill
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA 02215, USA
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
- Departments of Cell Biology and Pathology, Harvard Medical School, Boston, MA 02115, USA
| | - Salvador Casaní-Galdón
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA 02215, USA
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
- Departments of Cell Biology and Pathology, Harvard Medical School, Boston, MA 02115, USA
| | - Chadi A. El Farran
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA 02215, USA
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
- Departments of Cell Biology and Pathology, Harvard Medical School, Boston, MA 02115, USA
| | - Eli G. Cytrynbaum
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
- Departments of Cell Biology and Pathology, Harvard Medical School, Boston, MA 02115, USA
- Department of Pathology and Center for Cancer Research, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA
| | - Kevin A. Macias
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA 02215, USA
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
- Departments of Cell Biology and Pathology, Harvard Medical School, Boston, MA 02115, USA
| | - Sylvie E. Oldeman
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA 02215, USA
- Departments of Cell Biology and Pathology, Harvard Medical School, Boston, MA 02115, USA
| | - Kayla J. Oliveira
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
- Department of Pathology, Dana-Farber Cancer Institute, Boston, MA 02215, USA
| | - Molly M. Moore
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Esmat Hegazi
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
- Departments of Cell Biology and Pathology, Harvard Medical School, Boston, MA 02115, USA
- Department of Pathology and Center for Cancer Research, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA
| | - Carmen Adriaens
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA 02215, USA
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
- Departments of Cell Biology and Pathology, Harvard Medical School, Boston, MA 02115, USA
| | - Fadi J. Najm
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - George D. Demetri
- Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02215, USA
- Ludwig Center at Harvard, Harvard Medical School, Boston, MA 02115, USA
| | - Sonia Cohen
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA 02215, USA
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
- Departments of Cell Biology and Pathology, Harvard Medical School, Boston, MA 02115, USA
- Department of Surgery, Massachusetts General Hospital, Boston, MA 02114, USA
| | - John T. Mullen
- Department of Surgery, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Nicolò Riggi
- Department of Cell and Tissue Genomics (CTG), Genentech Inc, South San Francisco, CA 94080, USA
| | - Sarah E. Johnstone
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
- Department of Pathology, Dana-Farber Cancer Institute, Boston, MA 02215, USA
| | - Bradley E. Bernstein
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA 02215, USA
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
- Departments of Cell Biology and Pathology, Harvard Medical School, Boston, MA 02115, USA
- Ludwig Center at Harvard, Harvard Medical School, Boston, MA 02115, USA
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2
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Weinhouse C. The roles of inducible chromatin and transcriptional memory in cellular defense system responses to redox-active pollutants. Free Radic Biol Med 2021; 170:85-108. [PMID: 33789123 PMCID: PMC8382302 DOI: 10.1016/j.freeradbiomed.2021.03.018] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Revised: 03/12/2021] [Accepted: 03/15/2021] [Indexed: 12/17/2022]
Abstract
People are exposed to wide range of redox-active environmental pollutants. Air pollution, heavy metals, pesticides, and endocrine disrupting chemicals can disrupt cellular redox status. Redox-active pollutants in our environment all trigger their own sets of specific cellular responses, but they also activate a common set of general stress responses that buffer the cell against homeostatic insults. These cellular defense system (CDS) pathways include the heat shock response, the oxidative stress response, the hypoxia response, the unfolded protein response, the DNA damage response, and the general stress response mediated by the stress-activated p38 mitogen-activated protein kinase. Over the past two decades, the field of environmental epigenetics has investigated epigenetic responses to environmental pollutants, including redox-active pollutants. Studies of these responses highlight the role of chromatin modifications in controlling the transcriptional response to pollutants and the role of transcriptional memory, often referred to as "epigenetic reprogramming", in predisposing previously exposed individuals to more potent transcriptional responses on secondary challenge. My central thesis in this review is that high dose or chronic exposure to redox-active pollutants leads to transcriptional memories at CDS target genes that influence the cell's ability to mount protective responses. To support this thesis, I will: (1) summarize the known chromatin features required for inducible gene activation; (2) review the known forms of transcriptional memory; (3) discuss the roles of inducible chromatin and transcriptional memory in CDS responses that are activated by redox-active environmental pollutants; and (4) propose a conceptual framework for CDS pathway responsiveness as a readout of total cellular exposure to redox-active pollutants.
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Affiliation(s)
- Caren Weinhouse
- Oregon Institute of Occupational Health Sciences, Oregon Health & Science University, Portland, OR, 97214, USA.
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3
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Friedel L, Loewer A. The guardian's choice: how p53 enables context-specific decision-making in individual cells. FEBS J 2021; 289:40-52. [PMID: 33590949 DOI: 10.1111/febs.15767] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2020] [Revised: 02/03/2021] [Accepted: 02/15/2021] [Indexed: 01/20/2023]
Abstract
p53 plays a central role in defending the genomic integrity of our cells. In response to genotoxic stress, this tumour suppressor orchestrates the expression of hundreds of target genes, which induce a variety of cellular outcomes ranging from damage repair to induction of apoptosis. In this review, we examine how the p53 response is regulated on several levels in individual cells to allow precise and context-specific fate decisions. We discuss that the p53 response is not only controlled by its canonical regulators but also controlled by interconnected signalling pathways that influence the dynamics of p53 accumulation upon damage and modulate its transcriptional activity at target gene promoters. Additionally, we consider how the p53 response is diversified through a variety of mechanisms at the promoter level and beyond to induce context-specific outcomes in individual cells. These layers of regulation allow p53 to react in a stimulus-specific manner and fine-tune its signalling according to the individual needs of a given cell, enabling it to take the right decision on survival or death.
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Affiliation(s)
- Laura Friedel
- Systems Biology of the Stress Response, Department of Biology, Technical University of Darmstadt, Germany
| | - Alexander Loewer
- Systems Biology of the Stress Response, Department of Biology, Technical University of Darmstadt, Germany
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4
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Li R, Zatloukalova P, Muller P, Gil-Mir M, Kote S, Wilkinson S, Kemp AJ, Hernychova L, Wang Y, Ball KL, Tao K, Hupp T, Vojtesek B. The MDM2 ligand Nutlin-3 differentially alters expression of the immune blockade receptors PD-L1 and CD276. Cell Mol Biol Lett 2020; 25:41. [PMID: 32874188 PMCID: PMC7457494 DOI: 10.1186/s11658-020-00233-w] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Accepted: 08/21/2020] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND The links between the p53/MDM2 pathway and the expression of pro-oncogenic immune inhibitory receptors in tumor cells are undefined. In this report, we evaluate whether there is p53 and/or MDM2 dependence in the expression of two key immune receptors, CD276 and PD-L1. METHODS Proximity ligation assays were used to quantify protein-protein interactions in situ in response to Nutlin-3. A panel of p53-null melanoma cells was created using CRISPR-Cas9 guide RNA mediated genetic ablation. Flow cytometric analyses were used to assess the impact of TP53 or ATG5 gene ablation, as well as the effects of Nutlin-3 and an ATM inhibitor on cell surface PD-L1 and CD276. Targeted siRNA was used to deplete CD276 to assess changes in cell cycle parameters by flow cytometry. A T-cell proliferation assay was used to assess activity of CD4+ T-cells as a function of ATG5 genotype. RESULTS CD276 forms protein-protein interactions with MDM2 in response to Nutlin-3, similar to the known MDM2 interactors p53 and HSP70. Isogenic HCT116 p53-wt/null cancer cells demonstrated that CD276 is induced on the cell surface by Nutlin-3 in a p53-dependent manner. PD-L1 was also unexpectedly induced by Nutlin-3, but PD-L1 does not bind MDM2. The ATM inhibitor KU55993 reduced the levels of PD-L1 under conditions where Nutlin-3 induces PD-L1, indicating that MDM2 and ATM have opposing effects on PD-L1 steady-state levels. PD-L1 is also up-regulated in response to genetic ablation of TP53 in A375 melanoma cell clones under conditions in which CD276 remains unaffected. A549 cells with a deletion in the ATG5 gene up-regulated only PD-L1, further indicating that PD-L1 and CD276 are under distinct genetic control. CONCLUSION Genetic inactivation of TP53, or the use of the MDM2 ligand Nutlin-3, alters the expression of the immune blockade receptors PD-L1 and CD276. The biological function of elevated CD276 is to promote altered cell cycle progression in response to Nutlin-3, whilst the major effect of elevated PD-L1 is T-cell suppression. These data indicate that TP53 gene status, ATM and MDM2 influence PD-L1 and CD276 paralogs on the cell surface. These data have implications for the use of drugs that target the p53 pathway as modifiers of immune checkpoint receptor expression.
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Affiliation(s)
- Ruidong Li
- University of Edinburgh, Institute of Genetics and Molecular Medicine, Edinburgh, Scotland EH4 2XR UK
- Department of Gastrointestinal Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | | | - Petr Muller
- RECAMO, Masaryk Memorial Cancer Institute, 656 53 Brno, Czech Republic
| | - Maria Gil-Mir
- University of Edinburgh, Institute of Genetics and Molecular Medicine, Edinburgh, Scotland EH4 2XR UK
| | - Sachin Kote
- University of Gdansk, International Centre for Cancer Vaccine Science, ul. Wita Stwosza 63, 80-308 Gdansk, Poland
| | - Simon Wilkinson
- University of Edinburgh, Institute of Genetics and Molecular Medicine, Edinburgh, Scotland EH4 2XR UK
| | - Alain J. Kemp
- University of Edinburgh, Institute of Genetics and Molecular Medicine, Edinburgh, Scotland EH4 2XR UK
| | - Lenka Hernychova
- RECAMO, Masaryk Memorial Cancer Institute, 656 53 Brno, Czech Republic
| | - Yaxin Wang
- Department of Anesthesiology and Critical Care, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Kathryn L. Ball
- University of Edinburgh, Institute of Genetics and Molecular Medicine, Edinburgh, Scotland EH4 2XR UK
| | - Kaixiong Tao
- Department of Gastrointestinal Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Ted Hupp
- University of Edinburgh, Institute of Genetics and Molecular Medicine, Edinburgh, Scotland EH4 2XR UK
- RECAMO, Masaryk Memorial Cancer Institute, 656 53 Brno, Czech Republic
- University of Gdansk, International Centre for Cancer Vaccine Science, ul. Wita Stwosza 63, 80-308 Gdansk, Poland
| | - Borivoj Vojtesek
- RECAMO, Masaryk Memorial Cancer Institute, 656 53 Brno, Czech Republic
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5
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Barnoud T, Parris JLD, Murphy ME. Common genetic variants in the TP53 pathway and their impact on cancer. J Mol Cell Biol 2020; 11:578-585. [PMID: 31152665 PMCID: PMC6736421 DOI: 10.1093/jmcb/mjz052] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 04/24/2019] [Accepted: 05/15/2019] [Indexed: 01/09/2023] Open
Abstract
The TP53 gene is well known to be the most frequently mutated gene in human cancer. In addition to mutations, there are > 20 different coding region single-nucleotide polymorphisms (SNPs) in the TP53 gene, as well as SNPs in MDM2, the negative regulator of p53. Several of these SNPs are known to alter p53 pathway function. This makes p53 rather unique among cancer-critical genes, e.g. the coding regions of other cancer-critical genes like Ha-Ras, RB, and PI3KCA do not have non-synonymous coding region SNPs that alter their function in cancer. The next frontier in p53 biology will consist of probing which of these coding region SNPs are moderately or strongly pathogenic and whether they influence cancer risk and the efficacy of cancer therapy. The challenge after that will consist of determining whether we can tailor chemotherapy to correct the defects for each of these variants. Here we review the SNPs in TP53 and MDM2 that show the most significant impact on cancer and other diseases. We also propose avenues for how this information can be used to better inform personalized medicine approaches to cancer and other diseases.
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Affiliation(s)
- Thibaut Barnoud
- Program in Molecular and Cellular Oncogenesis, The Wistar Institute, Philadelphia, PA, USA
| | - Joshua L D Parris
- Program in Molecular and Cellular Oncogenesis, The Wistar Institute, Philadelphia, PA, USA.,Cell and Molecular Biology Program, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - Maureen E Murphy
- Program in Molecular and Cellular Oncogenesis, The Wistar Institute, Philadelphia, PA, USA
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6
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Jasti N, Sebagh D, Riaz M, Wang X, Koripella B, Palanisamy V, Mohammad N, Chen Q, Friedrich M. Towards reconstructing the dipteran demise of an ancient essential gene: E3 ubiquitin ligase Murine double minute. Dev Genes Evol 2020; 230:279-294. [PMID: 32623522 DOI: 10.1007/s00427-020-00663-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Accepted: 06/21/2020] [Indexed: 01/09/2023]
Abstract
Genome studies have uncovered many examples of essential gene loss, raising the question of how ancient genes transition from essentiality to dispensability. We explored this process for the deeply conserved E3 ubiquitin ligase Murine double minute (Mdm), which is lacking in Drosophila despite the conservation of its main regulatory target, the cellular stress response gene p53. Conducting gene expression and knockdown experiments in the red flour beetle Tribolium castaneum, we found evidence that Mdm has remained essential in insects where it is present. Using bioinformatics approaches, we confirm the absence of the Mdm gene family in Drosophila, mapping its loss to the stem lineage of schizophoran Diptera and Pipunculidae (big-headed flies), about 95-85 million years ago. Intriguingly, this gene loss event was preceded by the de novo origin of the gene Companion of reaper (Corp), a novel p53 regulatory factor that is characterized by functional similarities to vertebrate Mdm2 despite lacking E3 ubiquitin ligase protein domains. Speaking against a 1:1 compensatory gene gain/loss scenario, however, we found that hoverflies (Syrphidae) and pointed-wing flies (Lonchopteridae) possess both Mdm and Corp. This implies that the two p53 regulators have been coexisting for ~ 150 million years in select dipteran clades and for at least 50 million years in the lineage to Schizophora and Pipunculidae. Given these extensive time spans of Mdm/Corp coexistence, we speculate that the loss of Mdm in the lineage to Drosophila involved further acquisitions of compensatory gene activities besides the emergence of Corp. Combined with the previously noted reduction of an ancestral P53 contact domain in the Mdm homologs of crustaceans and insects, we conclude that the loss of the ancient Mdm gene family in flies was the outcome of incremental functional regression over long macroevolutionary time scales.
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Affiliation(s)
- Naveen Jasti
- Department of Biological Sciences, Wayne State University, 5047 Gullen Mall, Detroit, MI, 48202, USA.,Institute for Protein Design, Washington University, 1959 NE Pacific Street, Seattle, WA, 98195, USA
| | - Dylan Sebagh
- Department of Biological Sciences, Wayne State University, 5047 Gullen Mall, Detroit, MI, 48202, USA
| | - Mohammed Riaz
- Department of Biological Sciences, Wayne State University, 5047 Gullen Mall, Detroit, MI, 48202, USA
| | - Xin Wang
- Department of Biological Sciences, Wayne State University, 5047 Gullen Mall, Detroit, MI, 48202, USA
| | - Bharat Koripella
- Department of Biological Sciences, Wayne State University, 5047 Gullen Mall, Detroit, MI, 48202, USA
| | - Vasanth Palanisamy
- Department of Biological Sciences, Wayne State University, 5047 Gullen Mall, Detroit, MI, 48202, USA
| | - Nabeel Mohammad
- Department of Biological Sciences, Wayne State University, 5047 Gullen Mall, Detroit, MI, 48202, USA
| | - Qing Chen
- Department of Biological Sciences, Wayne State University, 5047 Gullen Mall, Detroit, MI, 48202, USA
| | - Markus Friedrich
- Department of Biological Sciences, Wayne State University, 5047 Gullen Mall, Detroit, MI, 48202, USA. .,Department of Anatomy and Cell Biology, Wayne State University, School of Medicine, 540 East Canfield Avenue, Detroit, MI, 48201, USA.
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7
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Li W, Peng X, Lang J, Xu C. Targeting Mouse Double Minute 2: Current Concepts in DNA Damage Repair and Therapeutic Approaches in Cancer. Front Pharmacol 2020; 11:631. [PMID: 32477121 PMCID: PMC7232544 DOI: 10.3389/fphar.2020.00631] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Accepted: 04/21/2020] [Indexed: 01/14/2023] Open
Abstract
Defects in DNA damage repair may cause genome instability and cancer development. The tumor suppressor gene p53 regulates cell cycle arrest to allow time for DNA repair. The oncoprotein mouse double minute 2 (MDM2) promotes cell survival, proliferation, invasion, and therapeutic resistance in many types of cancer. The major role of MDM2 is to inhibit p53 activity and promote its degradation. In this review, we describe the influence of MDM2 on genomic instability, the role of MDM2 on releasing p53 and binding DNA repair proteins to inhibit repair, and the regulation network of MDM2 including its transcriptional modifications, protein stability, and localization following DNA damage in genome integrity maintenance and in MDM2-p53 axis control. We also discuss p53-dependent and p53 independent oncogenic function of MDM2 and the outcomes of clinical trials that have been used with clinical inhibitors targeting p53-MDM2 to treat certain cancers.
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Affiliation(s)
- Wen Li
- Cancer Clinical Research Center & Integrative Cancer Center, Sichuan Cancer Hospital & Institute Sichuan Cancer Center, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
| | - Xinhao Peng
- Cancer Clinical Research Center & Integrative Cancer Center, Sichuan Cancer Hospital & Institute Sichuan Cancer Center, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China.,Radiation Oncology Key Laboratory of Sichuan Province, Sichuan Cancer Hospital & Institute Sichuan Cancer Center, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
| | - Jinyi Lang
- Cancer Clinical Research Center & Integrative Cancer Center, Sichuan Cancer Hospital & Institute Sichuan Cancer Center, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China.,Radiation Oncology Key Laboratory of Sichuan Province, Sichuan Cancer Hospital & Institute Sichuan Cancer Center, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
| | - Chuan Xu
- Cancer Clinical Research Center & Integrative Cancer Center, Sichuan Cancer Hospital & Institute Sichuan Cancer Center, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
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8
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Zhao L, Li C, Zhou B, Luo C, Wang Y, Che L, Zhao J, Xu Y. Crucial role of serum response factor in renal tubular epithelial cell epithelial-mesenchymal transition in hyperuricemic nephropathy. Aging (Albany NY) 2019; 11:10597-10609. [PMID: 31774735 PMCID: PMC6914413 DOI: 10.18632/aging.102479] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Accepted: 11/08/2019] [Indexed: 11/29/2022]
Abstract
Objective: To explore the regulation and function of serum response factor (SRF) in epithelial-mesenchymal transition (EMT) in renal tubular epithelial cells (TECs) in hyperuricemic nephropathy (HN). Results: In NRK-52E cells treated with UA and renal medulla tissue samples from hyperuricemic rats, SRF, fibronectin, α-SMA and FSP-1 expression was upregulated, while ZO-1 and E-cadherin expression was downregulated. SRF upregulation in NRK-52E cells increased slug expression. Blockade of SRF by an SRF-specific siRNA or CCG-1423 reduced slug induction and protected TECs from undergoing EMT both in vitro and in vivo. Conclusion: Increased SRF activity promotes EMT and dysfunction in TECs in HN. Targeting SRF with CCG-1423 may be an attractive therapeutic strategy in HN. Methods: The expression of SRF, mesenchymal markers (fibronectin, α-SMA, and FSP-1), epithelial markers (ZO-1 and E-cadherin) and was examined in rat renal TECs (NRK-52E cells) or renal medulla tissue samples following uric acid (UA) treatment. SRF overexpressed with pcDNA-SRF plasmid and suppressed by CCG-1423 (a small molecule inhibitor of SRF) to study how SRF influences EMT in TECs in HN. Oxonic acid (OA) was used to establish HN in rats.
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Affiliation(s)
- Long Zhao
- Department of Nephrology, The Affiliated Hospital of Qingdao University, Qingdao 266003, China
| | - Chenyu Li
- Department of Nephrology, The Affiliated Hospital of Qingdao University, Qingdao 266003, China
| | - Bin Zhou
- Department of Nephrology, The Affiliated Hospital of Qingdao University, Qingdao 266003, China
| | - Congjuan Luo
- Department of Nephrology, The Affiliated Hospital of Qingdao University, Qingdao 266003, China
| | - Yanfei Wang
- Department of Nephrology, The Affiliated Hospital of Qingdao University, Qingdao 266003, China
| | - Lin Che
- Department of Nephrology, The Affiliated Hospital of Qingdao University, Qingdao 266003, China
| | - Jun Zhao
- Department of Nephrology, Shandong Weifang People's Hospital, Weifang 261041, China
| | - Yan Xu
- Department of Nephrology, The Affiliated Hospital of Qingdao University, Qingdao 266003, China
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9
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Xue L, Han X, Liu R, Wang Z, Li H, Chen Q, Zhang P, Wang Z, Chong T. MDM2 and P53 polymorphisms contribute together to the risk and survival of prostate cancer. Oncotarget 2017; 7:31825-31. [PMID: 26025918 PMCID: PMC5077979 DOI: 10.18632/oncotarget.3923] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Accepted: 04/08/2015] [Indexed: 12/26/2022] Open
Abstract
The p53 gene and MDM2 gene play critical roles in cell cycle arrest and apoptosis together. Here, we evaluated the associations of prostate cancer risk and survival with the joint effects of mdm2 and p53 polymorphisms. Totally 1,193 cases and 1,310 age frequency-matched controls were included in the study. Prostate cancer patients were followed to determine the intervals of overall survival and disease-free survival. The Pro72Arg Pro allele (homozygous and heterozygous) were significantly associated with prostate cancer risk with an odds ratio (OR) of 0.77 [95% confidence interval(CI), 0.64-0.93]. SNP309 T alleles were associated with a significantly decreased prostate cancer risk among Pro72Arg Pro alleles carriers (OR=0.79, 95% CI, 0.64-0.98). In addition, comparedwith the Pro72Arg Pro alleles and SNP309 G homozygous, patients carrying both SNP309 T alleles and Pro72Arg Arg homozygous had more favorable disease-free survival (hazard ratio [HR] = 0.59, 95% CI, 0.38-0.93). Our results indicated that SNP309 and Pro72Arg polymorphisms may jointly contributeto the etiology and prognosis of prostate cancer.
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Affiliation(s)
- Li Xue
- Department of Urology, The Second Affiliated Hospital, Xi'an Jiaotong University, Xian, China
| | - Xiujuan Han
- The Helmholtz Sino-German Research Laboratory for Cancer, Department of Pathology, Tangdu Hospital, The Fourth Military Medical University, Xian, China
| | - Rongrong Liu
- Department of Pathology, School of Basic Medicine, Fourth Military Medical University, Xian, Shaanxi, China
| | - Ziming Wang
- Department of Urology, The Second Affiliated Hospital, Xi'an Jiaotong University, Xian, China
| | - Hecheng Li
- Department of Urology, The Second Affiliated Hospital, Xi'an Jiaotong University, Xian, China
| | - Qi Chen
- Department of Urology, The Second Affiliated Hospital, Xi'an Jiaotong University, Xian, China
| | - Peng Zhang
- Department of Urology, The Second Affiliated Hospital, Xi'an Jiaotong University, Xian, China
| | - Zhenlong Wang
- Department of Urology, The Second Affiliated Hospital, Xi'an Jiaotong University, Xian, China
| | - Tie Chong
- Department of Urology, The Second Affiliated Hospital, Xi'an Jiaotong University, Xian, China
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10
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Wienken M, Moll UM, Dobbelstein M. Mdm2 as a chromatin modifier. J Mol Cell Biol 2017; 9:74-80. [PMID: 27927750 PMCID: PMC5439376 DOI: 10.1093/jmcb/mjw046] [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] [Received: 06/11/2016] [Accepted: 10/30/2016] [Indexed: 12/21/2022] Open
Abstract
Mdm2 is the key negative regulator of the tumour suppressor p53, making it an attractive target for anti-cancer drug design. We recently identified a new role of Mdm2 in gene repression through its direct interaction with several proteins of the polycomb group (PcG) family. PcG proteins form polycomb repressive complexes PRC1 and PRC2. PRC2 (via EZH2) mediates histone 3 lysine 27 (H3K27) trimethylation, and PRC1 (via RING1B) mediates histone 2A lysine 119 (H2AK119) monoubiquitination. Both PRCs mostly support a compact and transcriptionally silent chromatin structure. We found that Mdm2 regulates a gene expression profile similar to that of PRC2 independent of p53. Moreover, Mdm2 promotes the stemness of murine induced pluripotent stem cells and human mesenchymal stem cells, and supports the survival of tumour cells. Mdm2 is recruited to target gene promoters by the PRC2 member and histone methyltransferase EZH2, and enhances PRC-dependent repressive chromatin modifications, specifically H3K27me3 and H2AK119ub1. Mdm2 also cooperates in gene repression with the PRC1 protein RING1B, a H2AK119 ubiquitin ligase. Here we discuss the possible implications of these p53-independent functions of Mdm2 in chromatin dynamics and in the stem cell phenotype. We propose that the p53-independent functions of Mdm2 should be taken into account for cancer drug design. So far, the majority of clinically tested Mdm2 inhibitors target its binding to p53 but do not affect the new functions of Mdm2 described here. However, when targeting the E3 ligase activity of Mdm2, a broader spectrum of its oncogenic activities might become druggable.
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Affiliation(s)
- Magdalena Wienken
- Institute of Molecular Oncology, Göttingen Center for Molecular Biosciences (GZMB), University Medical Center Göttingen, Göttingen 37077, Germany
| | - Ute M Moll
- Institute of Molecular Oncology, Göttingen Center for Molecular Biosciences (GZMB), University Medical Center Göttingen, Göttingen 37077, Germany.,Department of Pathology, School of Medicine, Stony Brook University, Stony Brook, NY 11794, USA
| | - Matthias Dobbelstein
- Institute of Molecular Oncology, Göttingen Center for Molecular Biosciences (GZMB), University Medical Center Göttingen, Göttingen 37077, Germany
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Balas M, Constanda S, Duma-Voiculet A, Prodana M, Hermenean A, Pop S, Demetrescu I, Dinischiotu A. Fabrication and toxicity characterization of a hybrid material based on oxidized and aminated MWCNT loaded with carboplatin. Toxicol In Vitro 2016; 37:189-200. [PMID: 27638054 DOI: 10.1016/j.tiv.2016.09.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Revised: 07/18/2016] [Accepted: 09/09/2016] [Indexed: 10/21/2022]
Abstract
This study focused on the fabrication and toxicity characterization of a hybrid material-based on the multiple functionalizations of multiwalled carbon nanotubes (MWCNTs) with carboxyl or amino groups and the anti-tumor drug carboplatin (CP). The functionalization was evidenced by Fourier transformed infrared spectroscopy (FTIR) and high performance liquid chromatography (HPLC). The amount of platinum ions released in the simulated body fluid (SBF) was assessed by inductively coupled plasma mass spectrometry (ICP-MS). Cell viability, nanotubes cellular uptake, cell proliferation, superoxide anion production, SOD activity, intracellular glutathione and protein expression of several molecules involved in breast tumor cell survival and death were investigated after 24h exposure. Exposure to the aminated carbon nanotubes loaded with carboplatin resulted in a greater decrease of viability compared to oxidized carbon nanotubes loaded with the same drug, which was in an inversely proportional relationship with the production of superoxide anions in breast cancer cells. The inhibition of Hsp60, Hsp90, p53 and Mdm2 protein expression was induced as a consequence of the cytoprotection mechanism failure. Overexpression of Beclin1 and the reduction of Bcl2 expression were also observed, suggesting that functionalized MWCNT loaded with CP trigger cell death via autophagy in breast cancer cells.
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Affiliation(s)
- Mihaela Balas
- University of Bucharest, Faculty of Biology, Department of Biochemistry and Molecular Biology, Splaiul Independentei 91-95, 50095 Bucharest, Romania
| | - Sabrina Constanda
- University of Bucharest, Faculty of Biology, Department of Biochemistry and Molecular Biology, Splaiul Independentei 91-95, 50095 Bucharest, Romania
| | - Adriana Duma-Voiculet
- University Politehnica of Bucharest, Faculty of Applied Chemistry and Materials Science, 1-7 Polizu, 011061 Bucharest, Romania
| | - Mariana Prodana
- University Politehnica of Bucharest, Faculty of Applied Chemistry and Materials Science, 1-7 Polizu, 011061 Bucharest, Romania
| | - Anca Hermenean
- Department of Experimental and Applied Biology, Institute of Life Sciences, Vasile Goldis Western University of Arad, 86 Rebreanu, Arad 310414, Romania; Department of Histology, Faculty of Medicine, Vasile Goldis Western University of Arad, 1 Feleacului, Arad 310396, Romania
| | - Sevinci Pop
- Victor Babes National Institute of Pathology, Bucharest, Splaiul Independenţei 99 - 101, 050096, Romania
| | - Ioana Demetrescu
- University Politehnica of Bucharest, Faculty of Applied Chemistry and Materials Science, 1-7 Polizu, 011061 Bucharest, Romania
| | - Anca Dinischiotu
- University of Bucharest, Faculty of Biology, Department of Biochemistry and Molecular Biology, Splaiul Independentei 91-95, 50095 Bucharest, Romania.
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12
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Yadav P, Masroor M, Tanwer K, Mir R, Javid J, Ahmad I, Zuberi M, Kaza RCM, Jain SK, Khurana N, Ray PC, Saxena A. Clinical significance of TP53 (R72P) and MDM2 (T309G) polymorphisms in breast cancer patients. Clin Transl Oncol 2015; 18:728-34. [PMID: 26553387 DOI: 10.1007/s12094-015-1425-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Accepted: 10/08/2015] [Indexed: 12/16/2022]
Abstract
INTRODUCTION TP53 gene is the most frequently altered tumor suppressor gene in breast cancer. It has been observed that MDM2 plays a central role in regulating the TP53 pathway. This study aimed to investigate the role of TP53 Arg72Pro and MDM2 T309G polymorphisms in breast cancer patients. MATERIAL AND METHOD The TP53 (Arg72Pro) and MDM2 (T309G) polymorphisms were studied in a hospital-based case control study by AS-PCR in 100 breast cancer patients and 100 healthy control subjects. RESULTS It was observed that TP53 Arg72Pro polymorphism was significantly associated with breast cancer (χ (2) = 9.92, p = 0.007). A significantly increased breast cancer risk was associated with the Proline allele [odds ratio 1.84 (95 % CI: 1.22-2.77), risk ratio 1.34 (95 % CI: 1.11-1.63), p value 0.003], HER2/neu status (p = 0.01) and distant metastasis (p = 0.05). On the other hand, we have found a significant correlation between MDM2 (T309G) polymorphism with HER2/neu status (χ (2) = 11.14, p = 0.003) and distant metastasis (p value = 0.04). CONCLUSION Our finding suggests that TP53 (Arg72Pro) polymorphism may play a significant role as risk factor for breast cancer in north Indian breast cancer patients. While MDM2 (T309G) polymorphism may not be directly associated with the risk of breast cancer occurrence in the same population, but it may play role in disease progression by triggering TP53.
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Affiliation(s)
- P Yadav
- Department of Biochemistry, Maulana Azad Medical College and Associated Hospitals, New Delhi, 110002, India
| | - M Masroor
- Department of Biochemistry, Maulana Azad Medical College and Associated Hospitals, New Delhi, 110002, India
| | - K Tanwer
- Department of Biochemistry, Maulana Azad Medical College and Associated Hospitals, New Delhi, 110002, India
| | - R Mir
- Faculty of Applied Medical Sciences, University of Tabuk, Tabuk, 71491, Saudi Arabia
| | - J Javid
- Faculty of Applied Medical Sciences, University of Tabuk, Tabuk, 71491, Saudi Arabia
| | - I Ahmad
- Department of Biochemistry, Maulana Azad Medical College and Associated Hospitals, New Delhi, 110002, India
| | - M Zuberi
- Department of Biochemistry, Maulana Azad Medical College and Associated Hospitals, New Delhi, 110002, India
| | - R C M Kaza
- Department of Surgery, Maulana Azad Medical College and Associated Hospitals, New Delhi, India
| | - S K Jain
- Department of Surgery, Maulana Azad Medical College and Associated Hospitals, New Delhi, India
| | - N Khurana
- Department of Pathology, Maulana Azad Medical College and Associated Hospitals, New Delhi, India
| | - P C Ray
- Department of Biochemistry, Maulana Azad Medical College and Associated Hospitals, New Delhi, 110002, India
| | - A Saxena
- Department of Biochemistry, Maulana Azad Medical College and Associated Hospitals, New Delhi, 110002, India.
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Rosso M, Polotskaia A, Bargonetti J. Homozygous mdm2 SNP309 cancer cells with compromised transcriptional elongation at p53 target genes are sensitive to induction of p53-independent cell death. Oncotarget 2015; 6:34573-91. [PMID: 26416444 PMCID: PMC4741474 DOI: 10.18632/oncotarget.5312] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Accepted: 09/07/2015] [Indexed: 11/25/2022] Open
Abstract
A single nucleotide polymorphism (T to G) in the mdm2 P2 promoter, mdm2 SNP309, leads to MDM2 overexpression promoting chemotherapy resistant cancers. Two mdm2 G/G SNP309 cancer cell lines, MANCA and A875, have compromised wild-type p53 that co-localizes with MDM2 on chromatin. We hypothesized that MDM2 in these cells inhibited transcription initiation at the p53 target genes p21 and puma. Surprisingly, following etoposide treatment transcription initiation occurred at the compromised target genes in MANCA and A875 cells similar to the T/T ML-1 cell line. In all cell lines tested there was equally robust recruitment of total and initiated RNA polymerase II (Pol II). We found that knockdown of MDM2 in G/G cells moderately increased expression of subsets of p53 target genes without increasing p53 stability. Importantly, etoposide and actinomycin D treatments increased histone H3K36 trimethylation in T/T, but not G/G cells, suggesting a G/G correlated inhibition of transcription elongation. We therefore tested a chemotherapeutic agent (8-amino-adenosine) that induces p53-independent cell death for higher clinically relevant cytotoxicity. We demonstrated that T/T and G/G mdm2 SNP309 cells were equally sensitive to 8-amino-adenosine induced cell death. In conclusion for cancer cells overexpressing MDM2, targeting MDM2 may be less effective than inducing p53-independent cell death.
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Affiliation(s)
- Melissa Rosso
- The Department of Biological Sciences Hunter College at The Belfer Research Building and The Graduate Center Biology PhD Program, CUNY, New York, NY 10021, USA
| | - Alla Polotskaia
- The Department of Biological Sciences Hunter College at The Belfer Research Building and The Graduate Center Biology PhD Program, CUNY, New York, NY 10021, USA
| | - Jill Bargonetti
- The Department of Biological Sciences Hunter College at The Belfer Research Building and The Graduate Center Biology PhD Program, CUNY, New York, NY 10021, USA
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Wang X, Jin L, Cui J, Ma K, Chen X, Li W. Mouse double minute-2 homolog (MDM2)-rs2279744 polymorphism associated with lung cancer risk in a Northeastern Chinese population. Thorac Cancer 2015; 6:91-6. [PMID: 26273341 PMCID: PMC4448458 DOI: 10.1111/1759-7714.12153] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2014] [Accepted: 07/16/2014] [Indexed: 12/02/2022] Open
Abstract
Background Altered expression or function of mouse double minute-2 (MDM2) protein could contribute to lung carcinogenesis; thus, this study investigated MDM2-rs2279744 polymorphism together with other epidemiologic factors for their association with lung cancer risk. Methods A total of 500 lung cancer patients and 500 age and gender-matched healthy controls living in Northeastern China were recruited for genotyping of MDM2-rs2279744. Clinicopathological data was collected and subjected to univariate and multivariate analyses. Results In univariate analysis, the MDM2-rs2279744 G/G genotype versus T/T + T/G genotypes showed a tendency toward a higher incidence of lung cancer in the recessive model (P = 0.043). However, there were no significant differences when it was analyzed by the dominant, additive, or multiplicative models. A significantly increased lung cancer risk was observed associated with lower education level, lower body mass index, cancer family history, prior diagnosis of chronic obstructive pulmonary disease and pneumonia, exposure to pesticide or gasoline/diesel, tobacco smoking, and heavy cooking emissions when assessed by multivariate analyses. Moreover, MDM2-rs2279744 was still a significant risk factor even after incorporating environmental and lifestyle factors. However, there was no association between MDM2-rs2279744 and other factors. Conclusions The MDM2-rs2279744 G/G genotype was associated with a higher lung cancer risk, even after incorporating other epidemiologic factors.
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Affiliation(s)
- Xu Wang
- Cancer Center, First Affiliated Hospital, Jilin University Changchun, China
| | - Lina Jin
- School of Public Health, Jilin University Changchun, China
| | - Jiuwei Cui
- Cancer Center, First Affiliated Hospital, Jilin University Changchun, China
| | - Kewei Ma
- Cancer Center, First Affiliated Hospital, Jilin University Changchun, China
| | - Xiao Chen
- Cancer Center, First Affiliated Hospital, Jilin University Changchun, China
| | - Wei Li
- Cancer Center, First Affiliated Hospital, Jilin University Changchun, China
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Zheng D, Chen Y, Gao C, Wei Y, Cao G, Lu N, Hou Y, Jiang X, Wang J. Polymorphisms of p53 and MDM2 genes are associated with severe toxicities in patients with non-small cell lung cancer. Cancer Biol Ther 2015; 15:1542-51. [PMID: 25482940 DOI: 10.4161/15384047.2014.956599] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Adverse events in platinum-based chemotherapy for patients with advanced non-small cell lung cancer (NSCLC) are major challenges. In this study, we investigated the role of the p53 and MDM2 genes in predicting adverse events in NSCLC patients treated with platinum-based chemotherapy. Specifically, we examined the p53 p. Pro72Arg (rs1042522), MDM2 c.14 + 309T>G (rs2279744) and MDM2 c.- 461C > G (rs937282) polymorphisms using PCR-based restriction fragment length polymorphism (RFLP) in 444 NSCLC patients. We determine that MDM2 c.14 + 309T > G was significantly associated with severe hematologic and overall toxicities for advanced NSCLC patients treated with platinum-based chemotherapy, especially for patients aged 57 and younger. This was also true for patients with adenocarcinoma. Second, we determine that severe gastrointestinal toxicities in patients with heterozygous MDM2 c.-461C > G were significantly higher than in patients with the G/G genotype. Third, patients with the MDM2 c.-461C > G - c.14 + 309T > G CT haplotype show much higher toxicities than those of CG haplotype. Moreover, patients carrying the MDM2 c.-461 > G -c.14 + 309T > G CG/CT diplotype exhibited higher toxicities than those carrying CG/CG. Fourth, we found that the p53 p. Pro72Arg polymorphism interacts with both age and genotype. In addition, no significant associations were observed between the 3 SNPs and the response to first-line platinum-based chemotherapy in advanced NSCLC patients. In summary, we found that the p53 p. Pro72Arg, MDM2 c.14 + 309T > G and MDM2 c.-461C > G polymorphisms are associated with toxicity risks following platinum-based chemotherapy treatment in advanced NSCLC patients. We suggest that MDM2 c.14 + 309T > G may be used as a candidate biomarker to predict adverse events in advanced NSCLC patients who had platinum-based chemotherapy treatment.
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Key Words
- CBR, clinical benefit rate
- CR, complete response
- MDM2
- NSCLC, non-small cell lung cancer
- ORR, objective response rate
- PCR-RFLP, PCR-based restriction fragment length polymorphism
- PD, progressive disease
- PR, partial response
- PS, performance status
- SCLC, small-cell lung cancer
- SD, stable disease
- SNP, single nucleotide polymorphism
- TNM, tumor/node/metastasis
- non-small cell lung cancer
- p53
- polymorphism
- toxicity
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Affiliation(s)
- Datong Zheng
- a Department of Biological Science and Technology and State Key Laboratory of Pharmaceutical Biotechnology; School of Life Sciences ; Nanjing University ; Nanjing , China
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16
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Genetic risk of subsequent esophageal cancer in lymphoma and breast cancer long-term survival patients: a pilot study. THE PHARMACOGENOMICS JOURNAL 2015; 16:266-71. [DOI: 10.1038/tpj.2015.41] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Revised: 04/22/2015] [Accepted: 04/28/2015] [Indexed: 02/06/2023]
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17
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He L, Che M, Hu J, Li S, Jia Z, Lou W, Li C, Yang J, Sun S, Wang H, Chen X. Twist contributes to proliferation and epithelial-to-mesenchymal transition-induced fibrosis by regulating YB-1 in human peritoneal mesothelial cells. THE AMERICAN JOURNAL OF PATHOLOGY 2015; 185:2181-93. [PMID: 26055210 DOI: 10.1016/j.ajpath.2015.04.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Revised: 04/05/2015] [Accepted: 04/23/2015] [Indexed: 10/23/2022]
Abstract
Twist is overexpressed in high glucose (HG) damage of human peritoneal mesothelial cells (HPMCs) in vitro. Herein, we further identified its precise function related to fibrosis of peritoneal membranes (PMs). The overexpression and activation of Twist and YB-1 (official name, YBX1) and a transformed fibroblastic phenotype of HPMCs were found to be positively related to epithelial-mesenchymal transition progress and PM fibrosis ex vivo in 93 patients who underwent continuous ambulatory peritoneal dialysis (PD), and also in HG-induced immortal HPMCs and an animal model of PD. Evidence from chromatin immunoprecipitation and luciferase reporter assays supported that YBX1 is transcriptionally regulated by the direct binding of Twist to E-box. Overexpression of Twist and YB-1 led to an increase in epithelial-mesenchymal transition, proliferation, and cell cycle progress of HPMCs, which might contribute to PM fibrosis. In contrast, the silencing of Twist or YB-1 inhibited HG-induced growth and cell cycle progression of HPMCs; this led to a down-regulation in the expression of cyclin Ds and cyclin-dependent kinases, finally inhibiting PM fibrosis. Twist contributes to PM fibrosis during PD treatment, mainly through regulation of YB-1.
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Affiliation(s)
- Lijie He
- Department of Nephrology, Xijing Hospital, the Fourth Military Medical University, Xi'an, Shaanxi, People's Republic of China; State Key Laboratory of Cancer Biology, Xijing Hospital, the Fourth Military Medical University, Xi'an, Shaanxi, People's Republic of China
| | - Mingwen Che
- Department of Nephrology, Xijing Hospital, the Fourth Military Medical University, Xi'an, Shaanxi, People's Republic of China; State Key Laboratory of Cancer Biology, Xijing Hospital, the Fourth Military Medical University, Xi'an, Shaanxi, People's Republic of China; Department of Medicine, No. 273 Hospital of PLA, Korla, Xinjiang, People's Republic of China
| | - Jinping Hu
- Department of Nephrology, Xijing Hospital, the Fourth Military Medical University, Xi'an, Shaanxi, People's Republic of China; State Key Laboratory of Cancer Biology, Xijing Hospital, the Fourth Military Medical University, Xi'an, Shaanxi, People's Republic of China
| | - Sutong Li
- Department of Nephrology, Xijing Hospital, the Fourth Military Medical University, Xi'an, Shaanxi, People's Republic of China; Department of Nephrology, the Central Hospital of Xi'an, Xi'an, Shaanxi, People's Republic of China
| | - Zhen Jia
- Department of Nephrology, Xijing Hospital, the Fourth Military Medical University, Xi'an, Shaanxi, People's Republic of China; Department of Nephrology, the First Hospital of Xi'an, Xi'an, Shaanxi, People's Republic of China
| | - Weijuan Lou
- Department of Nephrology, Xijing Hospital, the Fourth Military Medical University, Xi'an, Shaanxi, People's Republic of China
| | - Cuixiang Li
- Department of Nephrology, Xijing Hospital, the Fourth Military Medical University, Xi'an, Shaanxi, People's Republic of China
| | - Jun Yang
- Department of Nephrology, Xijing Hospital, the Fourth Military Medical University, Xi'an, Shaanxi, People's Republic of China
| | - Shiren Sun
- Department of Nephrology, Xijing Hospital, the Fourth Military Medical University, Xi'an, Shaanxi, People's Republic of China.
| | - Hanmin Wang
- Department of Nephrology, Xijing Hospital, the Fourth Military Medical University, Xi'an, Shaanxi, People's Republic of China.
| | - Xiangmei Chen
- Department of Nephrology, Xijing Hospital, the Fourth Military Medical University, Xi'an, Shaanxi, People's Republic of China; Department of Nephrology, State Key Laboratory of Kidney Diseases, Chinese PLA General Hospital and Medical College, Beijing, People's Republic of China
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18
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Zhang D, Ding Y, Wang Z, Wang Y, Zhao G. Impact of MDM2 gene polymorphism on sarcoma risk. Tumour Biol 2014; 36:1791-5. [PMID: 25366142 DOI: 10.1007/s13277-014-2781-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2014] [Accepted: 10/27/2014] [Indexed: 12/25/2022] Open
Abstract
A T>G single nucleotide polymorphism (SNP, rs2279744) of the MDM2 gene has been investigated in sarcoma community, but the findings are conflicting. This study was designed to well define the relationship between SNP rs2279744 and sarcoma risk. We did a systematic computerized search of the PubMed, Web of Science, and Science Direct databases to identify the human case-control studies investigating the relationship between SNP rs2279744 and sarcoma risk with complete genetic data. Pooled odds ratios (ORs) were calculated with the Mantel-Haenszel fixed-effect model or the DerSimonian and Laird random effects model to estimate the risk of sarcoma. Overall analysis included five independent studies. On the whole, the T/G genotype or the combined G/G and T/G genotypes appeared to be associated with approximately 1.40-fold higher risk of sarcoma relative to the T/T genotype (T/G vs. T/T: OR 1.33, 95% CI 1.00-1.77; G/G + T/G vs. T/T: OR 1.42, 95% CI 1.08-1.85). We noted that the Caucasian populations showed a similarly increased risk of sarcoma ascribed to the carriage of the same genotypes (T/G vs. T/T: OR 1.41, 95% CI 1.05-1.90; G/G + T/G vs. T/T: OR 1.49, 95% CI 1.13-1.97). This meta-analysis provides evidence that MDM2 SNP rs2279744 may be significantly associated with increased risk of sarcoma in Caucasian individuals.
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Affiliation(s)
- Dawei Zhang
- Department of Orthopedics, Xi Jing Hospital, The Fourth Military Medical University, Xi'an, 710032, China
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He L, Lou W, Ji L, Liang W, Zhou M, Xu G, Zhao L, Huang C, Li R, Wang H, Chen X, Sun S. Serum response factor accelerates the high glucose-induced Epithelial-to-Mesenchymal Transition (EMT) via snail signaling in human peritoneal mesothelial cells. PLoS One 2014; 9:e108593. [PMID: 25303231 PMCID: PMC4193747 DOI: 10.1371/journal.pone.0108593] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Accepted: 09/01/2014] [Indexed: 01/06/2023] Open
Abstract
Background Epithelial-to-Mesenchymal Transition (EMT) induced by glucose in human peritoneal mesothelial cells (HPMCs) is a major cause of peritoneal membrane (PM) fibrosis and dysfunction. Methods To investigate serum response factor (SRF) impacts on EMT-derived fibrosis in PM, we isolated HPMCs from the effluents of patients with end-stage renal disease (ESRD) to analyze alterations during peritoneal dialysis (PD) and observe the response of PM to SRF in a rat model. Results Our results demonstrated the activation and translocation of SRF into the nuclei of HPMCs under extensive periods of PD. Accordingly, HPMCs lost their epithelial morphology with a decrease in E-cadherin expression and an increase in α-smooth muscle actin (α-SMA) expression, implying a transition in phenotype. PD with 4.25% glucose solution significantly induced SRF up-regulation and increased peritoneal thickness. In immortal HPMCs, high glucose (HG, 60 mmol/L) stimulated SRF overexpression in transformed fibroblastic HPMCs. SRF-siRNA preserved HPMC morphology, while transfection of SRF plasmid into HPMCs caused the opposite effects. Evidence from electrophoretic mobility shift, chromatin immunoprecipitation and reporter assays further supported that SRF transcriptionally regulated Snail, a potent inducer of EMT, by directly binding to its promoter. Conclusions Our data suggested that activation of SRF/Snail pathway might contribute to the progressive PM fibrosis during PD.
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Affiliation(s)
- Lijie He
- Department of Nephrology, Xijing Hospital, the Fourth Military Medical University, Xi'an, Shaan xi, China
- State Key Laboratory of Cancer Biology, Xijing Hospital, the Fourth Military Medical University, Xi'an, Shaan xi, China
| | - Weijuan Lou
- Department of Nephrology, Xijing Hospital, the Fourth Military Medical University, Xi'an, Shaan xi, China
- State Key Laboratory of Cancer Biology, Xijing Hospital, the Fourth Military Medical University, Xi'an, Shaan xi, China
| | - Lihua Ji
- Department of Nephrology, Xijing Hospital, the Fourth Military Medical University, Xi'an, Shaan xi, China
- State Key Laboratory of Cancer Biology, Xijing Hospital, the Fourth Military Medical University, Xi'an, Shaan xi, China
- Department of Nephrology, Xingyuan Hospital, the Fourth Hospital of Yulin, Yulin, Shaan xi, China
| | - Wei Liang
- Department of Nephrology, Xijing Hospital, the Fourth Military Medical University, Xi'an, Shaan xi, China
- State Key Laboratory of Cancer Biology, Xijing Hospital, the Fourth Military Medical University, Xi'an, Shaan xi, China
- Department of Nephrology, the Ninth Hospital of Xi'an, Xi'an, Shaan xi, China
| | - Meilan Zhou
- Department of Nephrology, Xijing Hospital, the Fourth Military Medical University, Xi'an, Shaan xi, China
| | - Guoshang Xu
- Department of Nephrology, Xijing Hospital, the Fourth Military Medical University, Xi'an, Shaan xi, China
| | - Lijuan Zhao
- Department of Nephrology, Xijing Hospital, the Fourth Military Medical University, Xi'an, Shaan xi, China
| | - Chen Huang
- Department of Nephrology, Xijing Hospital, the Fourth Military Medical University, Xi'an, Shaan xi, China
| | - Rong Li
- Department of Nephrology, Xijing Hospital, the Fourth Military Medical University, Xi'an, Shaan xi, China
| | - Hanmin Wang
- Department of Nephrology, Xijing Hospital, the Fourth Military Medical University, Xi'an, Shaan xi, China
- State Key Laboratory of Cancer Biology, Xijing Hospital, the Fourth Military Medical University, Xi'an, Shaan xi, China
| | - Xiangmei Chen
- Department of Nephrology, Xijing Hospital, the Fourth Military Medical University, Xi'an, Shaan xi, China
- Department of Nephrology, State Key Laboratory of Kidney Diseases, Chinese PLA General Hospital and Medical College, Beijing, China
- * E-mail: (SRS); (XMC)
| | - Shiren Sun
- Department of Nephrology, Xijing Hospital, the Fourth Military Medical University, Xi'an, Shaan xi, China
- State Key Laboratory of Cancer Biology, Xijing Hospital, the Fourth Military Medical University, Xi'an, Shaan xi, China
- * E-mail: (SRS); (XMC)
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Peng Q, Lao X, Chen Z, Lai H, Deng Y, Wang J, Mo C, Sui J, Wu J, Zhai L, Yang S, Qin X, Li S. TP53 and MDM2 gene polymorphisms, gene-gene interaction, and hepatocellular carcinoma risk: evidence from an updated meta-analysis. PLoS One 2013; 8:e82773. [PMID: 24376578 PMCID: PMC3871586 DOI: 10.1371/journal.pone.0082773] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2013] [Accepted: 10/28/2013] [Indexed: 01/08/2023] Open
Abstract
Background The association between TP53 R72P and/or MDM2 SNP309 polymorphisms and hepatocellular carcinoma (HCC) risk has been widely reported, but results were inconsistent. To clarify the effects of these polymorphisms on HCC risk, an updated meta-analysis of all available studies was conducted. Methods Eligible articles were identified by search of databases including PubMed, Cochrane Library, EMBASE and Chinese Biomedical Literature database (CBM) for the period up to July 2013. Data were extracted by two independent authors and pooled odds ratio (OR) with 95% confidence interval (CI) was calculated. Metaregression and subgroup analyses were performed to identify the source of heterogeneity. Results Finally, a total of 10 studies including 2,243 cases and 3,615 controls were available for MDM2 SNP309 polymorphism and 14 studies containing 4,855 cases and 6,630 controls were included for TP53 R72P polymorphism. With respect to MDM2 SNP309 polymorphism, significantly increased HCC risk was found in the overall population. In subgroup analysis by ethnicity and hepatitis virus infection status, significantly increased HCC risk was found in Asians, Caucasians, Africans, and HCV positive patients. With respect to TP53 R72P polymorphism, no significant association with HCC risk was observed in the overall and subgroup analyses. In the MDM2 SNP309–TP53 R72P interaction analysis, we found that subjects with MDM2 309TT and TP53 Pro/Pro genotype, MDM2 309 TG and TP53 Arg/Pro genotype, and MDM2 309 GG and TP53 Pro/Pro genotype were associated with significantly increased risk of developing HCC as compared with the reference MDM2 309TT and TP53 Arg/Arg genotype. Conclusions We concluded that MDM2 SNP309 polymorphism may play an important role in the carcinogenesis of HCC. In addition, our findings further suggest that the combination of MDM2 SNP 309 and TP53 Arg72Pro genotypes confers higher risk to develop HCC. Further large and well-designed studies are needed to confirm this association.
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Affiliation(s)
- Qiliu Peng
- Department of Clinical Laboratory, First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China
| | - Xianjun Lao
- Department of Clinical Laboratory, First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China
| | - Zhiping Chen
- Department of Occupational Health and Environmental Health, School of Public Health at Guangxi Medical University, Nanning, Guangxi, China
| | - Hao Lai
- Department of Gastrointestinal Surgery, Tumor Hospital of Guangxi Medical University, Nanning, Guangxi, China
| | - Yan Deng
- Department of Clinical Laboratory, First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China
| | - Jian Wang
- Department of Clinical Laboratory, First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China
| | - Cuiju Mo
- Department of Clinical Laboratory, First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China
| | - Jingzhe Sui
- Department of Clinical Laboratory, First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China
| | - Junrong Wu
- Department of Clinical Laboratory, First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China
| | - Limin Zhai
- Department of Clinical Laboratory, First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China
| | - Shi Yang
- Department of Clinical Laboratory, First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China
| | - Xue Qin
- Department of Clinical Laboratory, First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China
- * E-mail: (XQ); (SL)
| | - Shan Li
- Department of Clinical Laboratory, First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China
- * E-mail: (XQ); (SL)
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McNally JP, Elfers EE, Terrell CE, Grunblatt E, Hildeman DA, Jordan MB, Katz JD. Eliminating encephalitogenic T cells without undermining protective immunity. THE JOURNAL OF IMMUNOLOGY 2013; 192:73-83. [PMID: 24277699 DOI: 10.4049/jimmunol.1301891] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The current clinical approach for treating autoimmune diseases is to broadly blunt immune responses as a means of preventing autoimmune pathology. Among the major side effects of this strategy are depressed beneficial immunity and increased rates of infections and tumors. Using the experimental autoimmune encephalomyelitis model for human multiple sclerosis, we report a novel alternative approach for purging autoreactive T cells that spares beneficial immunity. The moderate and temporally limited use of etoposide, a topoisomerase inhibitor, to eliminate encephalitogenic T cells significantly reduces the onset and severity of experimental autoimmune encephalomyelitis, dampens cytokine production and overall pathology, while dramatically limiting the off-target effects on naive and memory adaptive immunity. Etoposide-treated mice show no or significantly ameliorated pathology with reduced antigenic spread, yet have normal T cell and T-dependent B cell responses to de novo antigenic challenges as well as unimpaired memory T cell responses to viral rechallenge. Thus, etoposide therapy can selectively ablate effector T cells and limit pathology in an animal model of autoimmunity while sparing protective immune responses. This strategy could lead to novel approaches for the treatment of autoimmune diseases with both enhanced efficacy and decreased treatment-associated morbidities.
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Affiliation(s)
- Jonathan P McNally
- Division of Immunobiology, Cincinnati Children's Research Foundation, Cincinnati, OH 45229
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22
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Ruocco E, Ruocco V, Tornesello ML, Gambardella A, Wolf R, Buonaguro FM. Kaposi's sarcoma: etiology and pathogenesis, inducing factors, causal associations, and treatments: facts and controversies. Clin Dermatol 2013; 31:413-422. [PMID: 23806158 PMCID: PMC7173141 DOI: 10.1016/j.clindermatol.2013.01.008] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Kaposi's sarcoma (KS), an angioproliferative disorder, has a viral etiology and a multifactorial pathogenesis hinged on an immune dysfunction. The disease is multifocal, with a course ranging from indolent, with only skin manifestations to fulminant, with extensive visceral involvement. In the current view, all forms of KS have a common etiology in human herpesvirus (HHV)-8 infection, and the differences among them are due to the involvement of various cofactors. In fact, HHV-8 infection can be considered a necessary but not sufficient condition for the development of KS, because further factors (genetic, immunologic, and environmental) are required. The role of cofactors can be attributed to their ability to interact with HHV-8, to affect the immune system, or to act as vasoactive agents. In this contribution, a survey of the current state of knowledge on many and various factors involved in KS pathogenesis is carried out, in particular by highlighting the facts and controversies about the role of some drugs (quinine analogues and angiotensin-converting enzyme inhibitors) in the onset of the disease. Based on these assessments, it is possible to hypothesize that the role of cofactors in KS pathogenesis can move toward an effect either favoring or inhibiting the onset of the disease, depending on the presence of other agents modulating the pathogenesis itself, such as genetic predisposition, environmental factors, drug intake, or lymph flow disorders. It is possible that the same agents may act as either stimulating or inhibiting cofactors according to the patient’s genetic background and variable interactions. Treatment guidelines for each form of KS are outlined, because a unique standard therapy for all of them cannot be considered due to KS heterogeneity. In most cases, therapeutic options, both local and systemic, should be tailored to the patient’s peculiar clinical conditions.
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Affiliation(s)
- Eleonora Ruocco
- Department of Dermatology, Second University of Naples, via S. Pansini, 5 - 80131 Naples, Italy
| | - Vincenzo Ruocco
- Department of Dermatology, Second University of Naples, via S. Pansini, 5 - 80131 Naples, Italy.
| | - Maria Lina Tornesello
- Molecular Biology and Viral Oncology and AIDS Reference Centre, National Cancer Institute, "Fondazione Pascale," via M. Semmola - 80131 Naples, Italy
| | - Alessio Gambardella
- Department of Dermatology, Second University of Naples, via S. Pansini, 5 - 80131 Naples, Italy
| | - Ronni Wolf
- Dermatology Unit, Kaplan Medical Center, Rehovot 76100 Israel; The School of Medicine, Hebrew University and Hadassah Medical Center, Jerusalem, Israel
| | - Franco M Buonaguro
- Molecular Biology and Viral Oncology and AIDS Reference Centre, National Cancer Institute, "Fondazione Pascale," via M. Semmola - 80131 Naples, Italy
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23
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Okoro DR, Arva N, Gao C, Polotskaia A, Puente C, Rosso M, Bargonetti J. Endogenous human MDM2-C is highly expressed in human cancers and functions as a p53-independent growth activator. PLoS One 2013; 8:e77643. [PMID: 24147044 PMCID: PMC3795673 DOI: 10.1371/journal.pone.0077643] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2012] [Accepted: 09/12/2013] [Indexed: 01/22/2023] Open
Abstract
Human cancers over-expressing mdm2, through a T to G variation at a single nucleotide polymorphism at position 309 (mdm2 SNP309), have functionally inactivated p53 that is not effectively degraded. They also have high expression of the alternatively spliced transcript, mdm2-C. Alternatively spliced mdm2 transcripts are expressed in many forms of human cancer and when they are exogenously expressed they transform human cells. However no study to date has detected endogenous MDM2 protein isoforms. Studies with exogenous expression of splice variants have been carried out with mdm2-A and mdm2-B, but the mdm2-C isoform has remained virtually unexplored. We addressed the cellular influence of exogenously expressed MDM2-C, and asked if endogenous MDM2-C protein was present in human cancers. To detect endogenous MDM2-C protein, we created a human MDM2-C antibody to the splice junction epitope of exons four and ten (MDM2 C410) and validated the antibody with in vitro translated full length MDM2 compared to MDM2-C. Interestingly, we discovered that MDM2-C co-migrates with MDM2-FL at approximately 98 kDa. Using the validated C410 antibody, we detected high expression of endogenous MDM2-C in human cancer cell lines and human cancer tissues. In the estrogen receptor positive (ER+) mdm2 G/G SNP309 breast cancer cell line, T47D, we observed an increase in endogenous MDM2-C protein with estrogen treatment. MDM2-C localized to the nucleus and the cytoplasm. We examined the biological activity of MDM2-C by exogenously expressing the protein and observed that MDM2-C did not efficiently target p53 for degradation or reduce p53 transcriptional activity. Exogenous expression of MDM2-C in p53-null human cancer cells increased colony formation, indicating p53-independent tumorigenic properties. Our data indicate a role for MDM2-C that does not require the inhibition of p53 for increasing cancer cell proliferation and survival.
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Affiliation(s)
- Danielle R. Okoro
- Department of Biological Sciences Hunter College and The Graduate Center Departments of Biology and Biochemistry, City University of New York, New York City, United States of America
| | - Nicoleta Arva
- Department of Biological Sciences Hunter College and The Graduate Center Departments of Biology and Biochemistry, City University of New York, New York City, United States of America
| | - Chong Gao
- Department of Biological Sciences Hunter College and The Graduate Center Departments of Biology and Biochemistry, City University of New York, New York City, United States of America
| | - Alla Polotskaia
- Department of Biological Sciences Hunter College and The Graduate Center Departments of Biology and Biochemistry, City University of New York, New York City, United States of America
| | - Cindy Puente
- Department of Biological Sciences Hunter College and The Graduate Center Departments of Biology and Biochemistry, City University of New York, New York City, United States of America
| | - Melissa Rosso
- Department of Biological Sciences Hunter College and The Graduate Center Departments of Biology and Biochemistry, City University of New York, New York City, United States of America
| | - Jill Bargonetti
- Department of Biological Sciences Hunter College and The Graduate Center Departments of Biology and Biochemistry, City University of New York, New York City, United States of America
- * E-mail:
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Tuna G, Küçükhüseyin O, Arıkan S, Kaytan Sağlam E, Güler E, Cacına C, Oztop O, Turan S, Korkmaz G, Yaylım I. Do CDKN2 p16 540 C>G, CDKN2 p16 580 C>T, and MDM2 SNP309 T>G gene variants act on colorectal cancer development or progression? DNA Cell Biol 2013; 32:400-8. [PMID: 23777425 DOI: 10.1089/dna.2012.1933] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
CDNK2 p16 plays a pivotal role in G1/S transition by regulating the p53 pathway, which was regulated by a nuclear oncoprotein, mouse double minute 2 (MDM2). Overexpression of the MDM2 gene has been shown in a number of tumor types, its gene amplification is found to associate with accelerated tumor development and failure to treatment in both hereditary and sporadic cancers. Although genetic association studies have revealed the relationship between certain genetic polymorphisms and genes that play important roles in the development and progression of colorectal cancer (CRC), it is still unknown. Therefore, the polymorphisms of p16 540 C>G, 580 C>T, and MDM2 SNP309 T>G designed to investigate the risk of CRC development and progression in a Turkish population. We enrolled 87 patients with CRC and 75 healthy controls into the study. Genotypings were determined using polymerase chain reaction-restriction fragment length polymorphism techniques. Genotype distributions of p16 540 C>G and 580 C>T were found in agreement with the Hardy-Weinberg equilibrium in patients and controls. MDM2 SNP309 T>G was found in agreement with the Hardy-Weinberg equilibrium in controls, but not in patients. The results of our study, the G allele of p16 540 C>G and GG genotype of MDM2 SNP309 T>G were found significantly lower in patients compared with controls (p<0.001, p<0.05, respectively). Haplotype analyses have shown that the C allele of both the CDKN2 p16 540 C>G and 580 C>T variants together indicate a risk haplotype for the patient group; besides, carrying the G allele of p16 540 and G allele of MDM2 also seems a risk haplotype for the patient group. Our study is the first study that investigates the relationship among variants of CDKN2 p16 540 C>G, 580 C>T, and MDM2 SNP309 T>G risk of CRC and the development and progression in the Turkish population.
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Affiliation(s)
- Gülay Tuna
- Department of Molecular Medicine, The Institute of Experimental Medicine, Istanbul University, Istanbul, Turkey
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25
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Yoneda T, Kuboyama A, Kato K, Ohgami T, Okamoto K, Saito T, Wake N. Association of MDM2 SNP309 and TP53 Arg72Pro polymorphisms with risk of endometrial cancer. Oncol Rep 2013; 30:25-34. [PMID: 23624782 PMCID: PMC3729233 DOI: 10.3892/or.2013.2433] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2013] [Accepted: 03/28/2013] [Indexed: 01/30/2023] Open
Abstract
The incidence of endometrial cancer, a common gynecological malignancy, is increasing in Japan. We have previously shown that the ER/MDM2/p53/p21 pathway plays an important role in endometrial carcinogenesis. In the present study, we investigated the effects of germline single nucleotide polymorphisms in murine double minute 2 (MDM2) SNP309, TP53 Arg72Pro, ESR1 PvuII and XbaI, and p21 codon 31 on endometrial cancer risk. We evaluated these polymorphisms in DNA samples from 125 endometrial cancer cases and 200 controls using polymerase chain reaction-based restriction fragment length polymorphism. The association of each genetic polymorphism with endometrial cancer was examined by the odds ratio and 95% confidence interval, which were obtained using logistic regression analysis. The SNP309 GG genotype non-significantly increased the risk of endometrial cancer. The 95% confidence interval for the GG genotype vs. the TT genotype of MDM2 SNP309 was 1.76 (0.93–3.30). Endometrial cancer was not associated with tested SNP genotypes for TP53, ESR1 and p21. The combination of SNP309 GG + TG and TP53 codon 72 Arg/Arg significantly increased endometrial cancer risk. The adjusted OR was 2.53 (95% confidence interval, 1.03–6.21) and P for the interaction was 0.04. This result was supported by in vitro data showing that endometrial cancer cell lines with the SNP309 G allele failed to show growth inhibition by treatment with RITA, which reduces p53-MDM2 binding. The presence of the SNP309 G allele and TP53 codon 72 Arg/Arg genotype is associated with an increased risk of endometrial cancer in Japanese women.
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Affiliation(s)
- Tomoko Yoneda
- Department of Obstetrics and Gynecology, School of Medicine, Kyushu University, Fukuoka 812-8582, Japan
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26
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Meyer B, Voss KO, Tobias F, Jakob B, Durante M, Taucher-Scholz G. Clustered DNA damage induces pan-nuclear H2AX phosphorylation mediated by ATM and DNA-PK. Nucleic Acids Res 2013; 41:6109-18. [PMID: 23620287 PMCID: PMC3695524 DOI: 10.1093/nar/gkt304] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
DNA double-strand breaks (DSB) are considered as the most deleterious DNA lesions, and their repair is further complicated by increasing damage complexity. However, the molecular effects of clustered lesions are yet not fully understood. As the locally restricted phosphorylation of H2AX to form γH2AX is a key step in facilitating efficient DSB repair, we investigated this process after localized induction of clustered damage by ionizing radiation. We show that in addition to foci at damaged sites, H2AX is also phosphorylated in undamaged chromatin over the whole-cell nucleus in human and rodent cells, but this is not related to apoptosis. This pan-nuclear γH2AX is mediated by the kinases ataxia telangiectasia mutated and DNA-dependent protein kinase (DNA-PK) that also phosphorylate H2AX at DSBs. The pan-nuclear response is dependent on the amount of DNA damage and is transient even under conditions of impaired DSB repair. Using fluorescence recovery after photobleaching (FRAP), we found that MDC1, but not 53BP1, binds to the nuclear-wide γH2AX. Consequently, the accumulation of MDC1 at DSBs is reduced. Altogether, we show that a transient dose-dependent activation of the kinases occurring on complex DNA lesions leads to their nuclear-wide distribution and H2AX phosphorylation, yet without eliciting a full pan-nuclear DNA damage response.
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Affiliation(s)
- Barbara Meyer
- Department of Biophysics, GSI Helmholtz Center for Heavy Ion Research, Planckstrasse 1, D-64291 Darmstadt, Germany
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27
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Abstract
Cancer cells often have high expression of Mdm2. However, in many cancers mdm2 is alternatively spliced, with more than 40 mRNA variants identified. Many of the alternative spliced mdm2 mRNAs have the potential to encode truncated Mdm2 isoforms. These putative Mdm2 isoforms can theoretically increase the diversity of the cancer proteome. The 3 best characterized are Mdm2-A, Mdm2-B, and Mdm2-C. As described in this review, the exogenous expression of these isoforms results in paradoxical phenotypes of transformation-associated growth as well as the inhibition of growth. Interestingly, these Mdm2 isoforms contribute tumor-promoting capacity in p53-null backgrounds. Herein we describe how alternative splicing of mdm2 may result in Mdm2 protein products that alter signal transduction to promote tumorigenesis. The tumor promoting capacity of Mdm2 isoforms is discussed in the context of functions that do not require the inhibition of p53. When N-terminal portions of Mdm2 are missing, the biochemical functions encoded by exon 12 are proposed to become more important. This may result in growth promoting functions when wild-type p53 is absent or compromised. The p53-independent tumor promoting activity of Mdm2 is proposed to result from C-terminal biochemical contributions of DNA binding, RNA binding, nucleolar localization, and nucleotide binding.
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Affiliation(s)
- Danielle R Okoro
- The City University of New York at Hunter College and the Graduate Center, New York, NY, USA
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Abstract
p53 is an important tumor suppressor, functioning as a transcriptional activator and repressor. Upon receiving signals from multiple stress related pathways, p53 regulates numerous activities such as cell cycle arrest, senescence, and cell death. When p53 activities are not required, the protein is held in check by interacting with 2 key homologous regulators, Mdm2 and MdmX, and a search for inhibitors of these interactions is well underway. However, it is now recognized that Mdm2 and MdmX function beyond simple inhibition of p53, and a complete understanding of Mdm2 and MdmX functions is ever more important. Indeed, increasing evidence suggests that Mdm2 and MdmX affect p53 target gene specificity and influence the activity of other transcription factors, and Mdm2 itself may even function as a transcription co-factor through post-translational modification of chromatin. Additionally, Mdm2 affects post-transcriptional activities such as mRNA stability and translation of a variety of transcripts. Thus, Mdm2 and MdmX influence the expression of many genes through a wide variety of mechanisms, which are discussed in this review.
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Affiliation(s)
- Lynn Biderman
- Department of Biological Sciences, Columbia University, New York, NY, USA
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Lalonde ME, Ouimet M, Larivière M, Kritikou EA, Sinnett D. Identification of functional DNA variants in the constitutive promoter region of MDM2. Hum Genomics 2012; 6:15. [PMID: 23244604 PMCID: PMC3500213 DOI: 10.1186/1479-7364-6-15] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2012] [Accepted: 05/31/2012] [Indexed: 01/30/2023] Open
Abstract
Although mutations in the oncoprotein murine double minute 2 (MDM2) are rare, MDM2 gene overexpression has been observed in several human tumors. Given that even modest changes in MDM2 levels might influence the p53 tumor suppressor signaling pathway, we postulated that sequence variation in the promoter region of MDM2 could lead to disregulated expression and variation in gene dosage. Two promoters have been reported for MDM2; an internal promoter (P2), which is located near the end of intron 1 and is p53-responsive, and an upstream constitutive promoter (P1), which is p53-independent. Both promoter regions contain DNA variants that could influence the expression levels of MDM2, including the well-studied single nucleotide polymorphism (SNP) SNP309, which is located in the promoter P2; i.e., upstream of exon 2. In this report, we screened the promoter P1 for DNA variants and assessed the functional impact of the corresponding SNPs. Using the dbSNP database and genotyping validation in individuals of European descent, we identified three common SNPs (-1494 G > A; indel 40 bp; and -182 C > G). Three major promoter haplotypes were inferred by using these three promoter SNPs together with rs2279744 (SNP309). Following subcloning into a gene reporter system, we found that two of the haplotypes significantly influenced MDM2 promoter activity in a haplotype-specific manner. Site-directed mutagenesis experiments indicated that the 40 bp insertion/deletion variation is causing the observed allelic promoter activity. This study suggests that part of the variability in the MDM2 expression levels could be explained by allelic p53-independent P1 promoter activity.
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Affiliation(s)
- Marie-Eve Lalonde
- Division of Hematology-Oncology, Research Center, Sainte-Justine Hospital, 3175 Chemin de la Cote-Sainte-Catherine, Montreal H3T 1C5, Canada
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30
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Gu B, Zhu WG. Surf the post-translational modification network of p53 regulation. Int J Biol Sci 2012; 8:672-84. [PMID: 22606048 PMCID: PMC3354625 DOI: 10.7150/ijbs.4283] [Citation(s) in RCA: 164] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2012] [Accepted: 05/07/2012] [Indexed: 02/07/2023] Open
Abstract
Among the human genome, p53 is one of the first tumor suppressor genes to be discovered. It has a wide range of functions covering cell cycle control, apoptosis, genome integrity maintenance, metabolism, fertility, cellular reprogramming and autophagy. Although different possible underlying mechanisms for p53 regulation have been proposed for decades, none of them is conclusive. While much literature focuses on the importance of individual post-translational modifications, further explorations indicate a new layer of p53 coordination through the interplay of the modifications, which builds up a complex 'network'. This review focuses on the necessity, characteristics and mechanisms of the crosstalk among post-translational modifications and its effects on the precise and selective behavior of p53.
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Affiliation(s)
- Bo Gu
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Biochemistry and Molecular Biology, Peking University Health Science Center, Beijing 100191, China
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Nanosensing protein allostery using a bivalent mouse double minute two (MDM2) assay. Proc Natl Acad Sci U S A 2012; 109:8073-8. [PMID: 22556265 DOI: 10.1073/pnas.1116637109] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
The tumor suppressor protein, p53, is either mutated or absent in >50% of cancers and is negatively regulated by the mouse double minute (MDM2) protein. Understanding and inhibition of the MDM2-p53 interaction are, therefore, critical for developing novel chemotherapeutics, which are currently limited because of a lack of appropriate study tools. We present a nanosensing approach to investigate full-length MDM2 interactions with p53, thus providing an allosteric assay for identifying binding ligands. Surface-enhanced Raman scattering (SERS)-active nanoparticles, functionalized with a p53 peptide mimic (peptide 12.1), display biologically specific aggregation following addition of MDM2. Nanoparticle assembly is competitively inhibited by the N-terminal MDM2-binding ligands peptide 12.1 and Nutlin-3. This study reports nanoparticle assembly through specific protein-peptide interactions that can be followed by SERS. We demonstrate solution-based MDM2 allosteric interaction studies that use the full-length protein.
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Impact of MDM2 polymorphism: increased risk of developing colorectal cancer and a poor prognosis in the Tunisian population. Eur J Gastroenterol Hepatol 2012; 24:320-7. [PMID: 22266832 DOI: 10.1097/meg.0b013e32834bdf84] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
INTRODUCTION MDM2 was originally identified as an oncoprotein that binds to p53 and inhibits p53-mediated transactivation. Scientists have described functional single-nucleotide polymorphisms (SNP) in the MDM2 gene. They showed that the genotype of SNP 309 induces an increase in the level of MDM2 protein, which causes attenuation of the p53 pathway. In this study, we sought to investigate whether this polymorphism was related to risk of colorectal cancer and whether there were relationships between SNP 309 and protein expression or clinicopathological variables in Tunisian patients. MATERIALS AND METHODS To investigate the effect of this polymorphism in colorectal cancer pathogenesis, we genotyped 167 patients and 167 blood donors. Immunohistochemistry was performed on normal mucosa and tumor. RESULTS The rates of MDM2 genotypes were 6.6% for wild-type (T/T) and 93.4% for the SNP 309 polymorphic genotype (T/G and G/G) in patients and 38.3 and 61.7% in controls, respectively. There were significant differences in the frequencies of genotypes between patients and controls (P<0.01). We did not find any relationship between genotypes and clinicopathological features of patients, except in the case of the nonmucinous histological subtype (P=0.001). Moreover, we found that patients with the wild-type genotype (T/T) had significantly more favorable clinical outcome than did patients with the SNP 309 genotype (T/G, G/G) (P=0.005). In addition, we found an association between positive expression of p53 and polymorphic genotypes of MDM2 (T/G, G/G) (P=0.037). There was a significant association between tumoral immunostaning and MDM2 polymorphism (P=0.01). CONCLUSION Our results suggest that the MDM2 polymorphism is significantly associated with colorectal cancer risk and may provide useful prognostic information for Tunisian patients with colorectal cancer.
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The functional MDM2 T309G genetic variant but not P53 Arg72Pro polymorphism is associated with risk of sarcomas: a meta-analysis. J Cancer Res Clin Oncol 2011; 138:555-61. [DOI: 10.1007/s00432-011-1124-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2011] [Accepted: 12/09/2011] [Indexed: 02/08/2023]
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Di Vuolo V, Buonaguro L, Izzo F, Losito S, Botti G, Buonaguro FM, Tornesello ML. TP53 and MDM2 gene polymorphisms and risk of hepatocellular carcinoma among Italian patients. Infect Agent Cancer 2011; 6:13. [PMID: 21843334 PMCID: PMC3170208 DOI: 10.1186/1750-9378-6-13] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2011] [Accepted: 08/15/2011] [Indexed: 02/08/2023] Open
Abstract
Background Single-nucleotide polymorphisms within TP53 gene (codon 72 exon 4, rs1042522, encoding either arginine or proline) and MDM2 promoter (SNP309; rs2279744), have been independently associated with increased risk of several cancer types. Few studies have analysed the role of these polymorphisms in the development of hepatocellular carcinoma. Methods Genotype distribution of TP53 codon 72 and MDM2 SNP309 in 61 viral hepatitis-related hepatocellular carcinoma cases and 122 blood samples (healthy controls) from Italian subjects were determined by PCR and restriction fragment length polymorphism (RFLP). Results Frequencies of TP53 codon 72 alleles were not significantly different between cases and controls. A significant increase of MDM2 SNP309 G/G and T/G genotypes were observed among hepatocellular carcinoma cases (Odds Ratio, OR = 3.56, 95% Confidence Limits, 95% CI = 1.3-9.7; and OR = 2.82, 95% CI = 1.3-6.4, respectively). Conclusions These results highlight a significant role of MDM2 SNP309 G allele as a susceptibility gene for the development of viral hepatitis-related hepatocellular carcinoma among Italian subjects.
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Affiliation(s)
- Valeria Di Vuolo
- Molecular Biology and Viral Oncology and AIDS Ref, Centre, National Cancer Institute "Fond, Pascale", Naples, Italy.
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Wo X, Han D, Sun H, Liu Y, Meng X, Bai J, Chen F, Yu Y, Jin Y, Fu S. MDM2 SNP309 contributes to tumor susceptibility: a meta-analysis. J Genet Genomics 2011; 38:341-50. [PMID: 21867960 DOI: 10.1016/j.jgg.2011.07.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2011] [Revised: 07/18/2011] [Accepted: 07/18/2011] [Indexed: 02/07/2023]
Abstract
The potentially functional polymorphism, SNP309, in the promoter region of MDM2 gene has been implicated in cancer risk, but individual published studies showed inconclusive results. To obtain a more precise estimate of the association between MDM2 SNP309 and risk of cancer, we performed a meta-analysis of 70 individual studies in 59 publications that included 26,160 cases with different types of tumors and 33,046 controls. Summary odds ratios (OR) and corresponding 95% confidence intervals (CIs) were estimated using fixed- and random-effects models when appropriate. Overall, the variant genotypes were associated with a significantly increased cancer risk for all cancer types in different genetic models (GG vs. TT: OR, 1.123; 95% CI, 1.056-1.193; GG/GT vs. TT: OR, 1.028; 95% CI, 1.006-1.050). In the stratified analyses, the increased risk remained for the studies of most types of cancers, Asian populations, and hospital- /population-based studies in different genetic models, whereas significantly decreased risk was found in prostate cancer (GG vs. TT: OR, 0.606; 95% CI, 0.407-0.903; GG/GT vs. TT: OR, 0.748; 95% CI, 0.579-0.968). In conclusion, the data of meta-analysis suggests that MDM2 SNP309 is a potential biomarker for cancer risk.
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Affiliation(s)
- Xiaoman Wo
- Laboratory of Medical Genetics, Harbin Medical University, China
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Ohsaka Y, Nishino H. Polymorphisms in promoter sequences of MDM2, p53, and p16 genes in normal Japanese individuals. Genet Mol Biol 2011; 33:615-26. [PMID: 21637567 PMCID: PMC3036159 DOI: 10.1590/s1415-47572010000400004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2010] [Accepted: 07/02/2010] [Indexed: 02/11/2023] Open
Abstract
Research has been conducted to identify sequence polymorphisms of gene promoter regions in patients and control subjects, including normal individuals, and to determine the influence of these polymorphisms on transcriptional regulation in cells that express wild-type or mutant p53. In this study we isolated genomic DNA from whole blood of healthy Japanese individuals and sequenced the promoter regions of the MDM2, p53, and p16(INK4a) genes. We identified polymorphisms comprising 3 nucleotide substitutions at exon 1 and intron 1 regions of the MDM2 gene and 1 nucleotide insertion at a poly(C) nucleotide position in the p53 gene. The Japanese individuals also exhibited p16(INK4a) polymorphisms at several positions, including position -191. Reporter gene analysis by using luciferase revealed that the polymorphisms of MDM2, p53, and p16(INK4a) differentially altered luciferase activities in several cell lines, including the Colo320DM, U251, and T98G cell lines expressing mutant p53. Our results indicate that the promoter sequences of these genes differ among normal Japanese individuals and that polymorphisms can alter gene transcription activity.
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Affiliation(s)
- Yasuhito Ohsaka
- Department of Biochemistry and Molecular Biology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto Japan
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Cross B, Chen L, Cheng Q, Li B, Yuan ZM, Chen J. Inhibition of p53 DNA binding function by the MDM2 protein acidic domain. J Biol Chem 2011; 286:16018-29. [PMID: 21454483 DOI: 10.1074/jbc.m111.228981] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
MDM2 regulates p53 predominantly by promoting p53 ubiquitination. However, ubiquitination-independent mechanisms of MDM2 have also been implicated. Here we show that MDM2 inhibits p53 DNA binding activity in vitro and in vivo. MDM2 binding promotes p53 to adopt a mutant-like conformation, losing reactivity to antibody Pab1620, while exposing the Pab240 epitope. The acidic domain of MDM2 is required to induce p53 conformational change and inhibit p53 DNA binding. Alternate reading frame binding to the MDM2 acidic domain restores p53 wild type conformation and rescues DNA binding activity. Furthermore, histone methyl transferase SUV39H1 binding to the MDM2 acidic domain also restores p53 wild type conformation and allows p53-MDM2-SUV39H1 complex to bind DNA. These results provide further evidence for an ubiquitination-independent mechanism of p53 regulation by MDM2 and reveal how MDM2-interacting repressors gain access to p53 target promoters and repress transcription. Furthermore, we show that the MDM2 inhibitor Nutlin cooperates with the proteasome inhibitor Bortezomib by stimulating p53 DNA binding and transcriptional activity, providing a rationale for combination therapy using proteasome and MDM2 inhibitors.
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Affiliation(s)
- Brittany Cross
- Molecular Oncology Department, Moffitt Cancer Center, Tampa, Florida 33612, USA
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MDM2 SNP309 is associated with endometrial cancer susceptibility: a meta-analysis. Hum Cell 2011; 24:57-64. [PMID: 21547352 DOI: 10.1007/s13577-011-0013-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2010] [Accepted: 11/24/2010] [Indexed: 10/18/2022]
Abstract
Epidemiological studies have investigated the association between MDM2 promoter SNP 309 (T/G) and endometrial cancer susceptibility. However, the results are still controversial. To obtain a more precise estimate of the relationship, we conducted a meta-analysis of 1,001 cases and 1,889 controls from 6 published case-control studies (one of five articles contains two studies) to estimate the effect of SNP309 on endometrial cancer risk. The strength of association between MDM2 SNP309 and endometrial cancer susceptibility was assessed by calculating pooled odds ratios (ORs) with 95% confidence intervals (CIs). When all the eligible studies were pooled in the meta-analysis, we found that elevated endometrial cancer risk was significantly associated with GG variant genotype, however, heterozygous genotype TG seemed to be only a minor modifier on endometrial cancer risk (for GG vs. TT, OR = 1.54, 95% CI = 1.21-1.95, P = 0.0004; for TG vs. TT, OR = 0.96, 95% CI = 0.81-1.14, P = 0.66; for dominant model, OR = 1.09, 95% CI = 0.93-1.29, P = 0.29; for recessive model, OR = 1.65, 95% CI = 1.33-2.04, P < 0.00001). Overall, the meta-analysis suggested that the GG genotype of MDM2 SNP309 was significantly associated with the increased endometrial cancer risk.
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RNA content in the nucleolus alters p53 acetylation via MYBBP1A. EMBO J 2011; 30:1054-66. [PMID: 21297583 DOI: 10.1038/emboj.2011.23] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2010] [Accepted: 01/11/2011] [Indexed: 12/23/2022] Open
Abstract
A number of external and internal insults disrupt nucleolar structure, and the resulting nucleolar stress stabilizes and activates p53. We show here that nucleolar disruption induces acetylation and accumulation of p53 without phosphorylation. We identified three nucleolar proteins, MYBBP1A, RPL5, and RPL11, involved in p53 acetylation and accumulation. MYBBP1A was tethered to the nucleolus through nucleolar RNA. When rRNA transcription was suppressed by nucleolar stress, MYBBP1A translocated to the nucleoplasm and facilitated p53-p300 interaction to enhance p53 acetylation. We also found that RPL5 and RPL11 were required for rRNA export from the nucleolus. Depletion of RPL5 or RPL11 blocked rRNA export and counteracted reduction of nucleolar RNA levels caused by inhibition of rRNA transcription. As a result, RPL5 or RPL11 depletion inhibited MYBBP1A translocation and p53 activation. Our observations indicated that a dynamic equilibrium between RNA generation and export regulated nucleolar RNA content. Perturbation of this balance by nucleolar stress altered the nucleolar RNA content and modulated p53 activity.
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Sucheston L, Witonsky DB, Hastings D, Yildiz O, Clark VJ, Di Rienzo A, Onel K. Natural selection and functional genetic variation in the p53 pathway. Hum Mol Genet 2011; 20:1502-8. [PMID: 21266458 DOI: 10.1093/hmg/ddr028] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
The allele frequencies of two functional single-nucleotide polymorphisms (SNPs) in the p53 pathway, the MDM2 SNP309 and TP53 Arg72Pro, vary dramatically among populations. That the frequencies of the TP53 SNP follow a clinal distribution may suggest that selective pressure from environmental variables correlated with latitude contributed to these observed population differences. Recently, winter temperature and UV radiation were found to be significantly correlated with the TP53 and the MDM2 SNPs, respectively, in East Asians; whether these correlations are more extreme than expected based upon nonselective factors such as patterns of human migration remains unclear. Here, we genotyped these two SNPs in 971 unrelated individuals from 52 unique populations worldwide and tested for correlations with both latitude and a number of climate-related environmental variables on a global scale, controlling for these neutral processes. The TP53 SNP was associated with a significant selection signal for a few climate variables, such as short-wave radiation flux in the winter, but these signals were no longer significant after correction for multiple tests. The MDM2 SNP did not exhibit a significant signal with any climate variable. Therefore, these SNPs are unlikely to be under selective pressure driven by these variables. Thus, these data underscore the need to incorporate population history when assessing signatures of selection.
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Affiliation(s)
- Lara Sucheston
- Department of Cancer Prevention and Control, Roswell Park Cancer Institute, Buffalo, NY 14203, USA
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Brekman A, Singh KE, Polotskaia A, Kundu N, Bargonetti J. A p53-independent role of Mdm2 in estrogen-mediated activation of breast cancer cell proliferation. Breast Cancer Res 2011; 13:R3. [PMID: 21223569 PMCID: PMC3109566 DOI: 10.1186/bcr2804] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2010] [Revised: 11/17/2010] [Accepted: 01/11/2011] [Indexed: 12/14/2022] Open
Abstract
Introduction Estrogen receptor positive breast cancers often have high levels of Mdm2. We investigated if estrogen signaling in such breast cancers occurred through an Mdm2 mediated pathway with subsequent inactivation of p53. Methods We examined the effect of long-term 17β-estradiol (E2) treatment (five days) on the p53-Mdm2 pathway in estrogen receptor alpha (ERα) positive breast cancer cell lines that contain wild-type p53 (MCF-7 and ZR75-1). We assessed the influence of estrogen by examining cell proliferation changes, activation of transcription of p53 target genes, p53-chromatin interactions and cell cycle profile changes. To determine the effects of Mdm2 and p53 knockdown on the estrogen-mediated proliferation signals we generated MCF-7 cell lines with inducible shRNA for mdm2 or p53 and monitored their influence on estrogen-mediated outcomes. To further address the p53-independent effect of Mdm2 in ERα positive breast cancer we generated cell lines with inducible shRNA to mdm2 using the mutant p53 expressing cell line T-47D. Results Estrogen increased the Mdm2 protein level in MCF-7 cells without decreasing the p53 protein level. After estrogen treatment of MCF-7 cells, down-regulation of basal transcription of p53 target genes puma and p21 was observed. Estrogen treatment also down-regulated etoposide activated transcription of puma, but not p21. Mdm2 knockdown in MCF-7 cells increased p21 mRNA and protein, decreased cell growth in 3D matrigel and also decreased estrogen-induced cell proliferation in 2D culture. In contrast, knockdown of p53 had no effect on estrogen-induced cell proliferation. In T-47D cells with mutant p53, the knockdown of Mdm2 decreased estrogen-mediated cell proliferation but did not increase p21 protein. Conclusions Estrogen-induced breast cancer cell proliferation required a p53-independent role of Mdm2. The combined influence of genetic and environmental factors on the tumor promoting effects of estrogen implicated Mdm2 as a strong contributor to the bypass of cell cycle checkpoints. The novel finding that p53 was not the key target of Mdm2 in the estrogen activation of cell proliferation could have great benefit for future Mdm2-targeted breast cancer therapies.
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Affiliation(s)
- Angelika Brekman
- Department of Biological Sciences, Hunter College and The Graduate Center Biochemistry and Biology Programs, CUNY, 695 Park Ave, New York, NY 10065, USA
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Tornesello ML, Buonaguro L, Cristillo M, Biryahwaho B, Downing R, Hatzakis A, Alessi E, Cusini M, Ruocco V, Viviano E, Romano N, Katongole-Mbidde E, Buonaguro FM. MDM2 and CDKN1A gene polymorphisms and risk of Kaposi's sarcoma in African and Caucasian patients. Biomarkers 2010; 16:42-50. [PMID: 20979563 DOI: 10.3109/1354750x.2010.525664] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
A single-nucleotide polymorphism in the MDM2 promoter (SNP309; rs2279744) causes elevated transcription of this major negative regulator of p53 in several cancer types. We investigated MDM2 SNP309 and CDKN1A (p21/Waf1/Cip1) codon 31 (rs1801270) polymorphisms in 86 cases of cutaneous Kaposi's sarcoma (KS) from African and Caucasian patients, and 210 healthy controls. A significant increase of the MDM2 SNP309 T/G genotype was observed among classic KS cases (odds ratio 2.38, 95% confidence interval 1.0-5.5). Frequencies of CDKN1A codon 31 genotypes were not significantly different between cases and controls. The results suggest that the MDM2 SNP309 G allele may act as a susceptibility gene for the development of classic KS in Caucasian patients.
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Affiliation(s)
- Maria Lina Tornesello
- Molecular Biology and Viral Oncology and AIDS Reference Centre, National Cancer Institute, 'Fondazione Pascale', Naples, Italy
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Phillips CL, Gerbing R, Alonzo T, Perentesis JP, Harley ITW, Meshinchi S, Bhatla D, Radloff G, Davies SM. MDM2 polymorphism increases susceptibility to childhood acute myeloid leukemia: a report from the Children's Oncology Group. Pediatr Blood Cancer 2010; 55:248-53. [PMID: 20582981 PMCID: PMC2915901 DOI: 10.1002/pbc.22519] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
BACKGROUND The variant polymorphism in the gene MDM2, SNP309, leads to increased level of mdm2 protein and subsequent downregulation of p53 tumor suppressor pathway. Presence of this single nucleotide polymorphism (SNP) has been associated with earlier tumorigenesis in patients with Li-Fraumeni syndrome, as well as decreased survival in patients with CLL. In addition, cells homozygous (G/G) for SNP 309 were found to have 10-fold increase resistance to topoisomerase II inhibitors in vitro. PROCEDURE We genotyped children (n = 575) with de novo acute myeloid leukemia (AML) treated on three Children's Oncology Group protocols (CCG 2941/2961/AAML 03P1) for the presence of SNP309. Healthy blood donors were genotyped as control population. RESULTS The variant G/G genotype was associated with an increased susceptibility to AML (OR 1.5; P = 0.049). However, the presence of the variant allele at SNP309 did not modify disease response or toxicity in children treated on CCG protocols 2941/2961. CONCLUSIONS The variant SNP 309 influences susceptibility to pediatric AML, but does not impact overall response to therapy.
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Affiliation(s)
- Christine L Phillips
- Division of Hematology Oncology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio 45229, USA.
| | | | | | - John P Perentesis
- Division of Hematology Oncology, Cincinnati Children’s Hospital Medical Center and Department of Pediatrics, University of Cincinnati, Cincinnati, OH, USA
| | - Isaac TW Harley
- Division of Hematology Oncology, Cincinnati Children’s Hospital Medical Center and Department of Pediatrics, University of Cincinnati, Cincinnati, OH, USA
| | - Soheil Meshinchi
- Fred Hutchinson Cancer Research Center, University of Washington Medical Center, Seattle, WA, USA
| | - Deepika Bhatla
- Division of Hematology Oncology, Cincinnati Children’s Hospital Medical Center and Department of Pediatrics, University of Cincinnati, Cincinnati, OH, USA
| | - Gretchen Radloff
- Division of Hematology Oncology, Cincinnati Children’s Hospital Medical Center and Department of Pediatrics, University of Cincinnati, Cincinnati, OH, USA
| | - Stella M Davies
- Division of Hematology Oncology, Cincinnati Children’s Hospital Medical Center and Department of Pediatrics, University of Cincinnati, Cincinnati, OH, USA
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Muench P, Probst S, Schuetz J, Leiprecht N, Busch M, Wesselborg S, Stubenrauch F, Iftner T. Cutaneous papillomavirus E6 proteins must interact with p300 and block p53-mediated apoptosis for cellular immortalization and tumorigenesis. Cancer Res 2010; 70:6913-24. [PMID: 20663910 DOI: 10.1158/0008-5472.can-10-1307] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The binding of the papillomavirus E6 protein to E6AP and the induction of p53 degradation are common features of high-risk genital human papillomaviruses (HPV); cutaneous HPVs, on the other hand, lack these capacities. Nevertheless, several cutaneous HPV types of the beta-genus, such as HPV38 are associated with tumor formation when combined with genetic predisposition, immunosuppression, or UV exposure. In an animal model system, the cottontail rabbit papillomavirus (CRPV) rapidly induces skin cancer without additional cofactors, and CRPVE6 and E7 immortalize rabbit keratinocytes in vitro. However, CRPVE6 neither interacts with E6AP and p53 nor does it induce p53 degradation. In this study, we show that the interaction of CRPVE6, or HPV38E6, with the histone acetyltransferase p300 is crucial to inhibit the ability of p53 to induce apoptosis. Strikingly, E6 mutants deficient for p300 binding are incapable of preventing p53 acetylation, p53-dependent transcription, and apoptosis induction. Moreover, E6 mutants deficient for p300 binding cannot contribute to HPV38-induced immortalization of human keratinocytes or CRPV-induced tumor formation. Our findings highlight changes in the p53 acetylation status mediated by the viral E6 protein as a crucial requirement in the ability of high-risk cutaneous papillomaviruses to immortalize primary keratinocytes and induce tumors. Cancer Res; 70(17); 6913-24. (c)2010 AACR.
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Affiliation(s)
- Peter Muench
- Institute for Medical Virology and Epidemiology of Viral Diseases, University Hospital Tuebingen, Tuebingen, Germany
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Maslon MM, Hupp TR. Drug discovery and mutant p53. Trends Cell Biol 2010; 20:542-55. [PMID: 20656489 DOI: 10.1016/j.tcb.2010.06.005] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2010] [Revised: 06/14/2010] [Accepted: 06/15/2010] [Indexed: 12/24/2022]
Abstract
Missense mutations in the p53 gene are commonly selected for in developing human cancer cells. These diverse mutations in p53 can inactivate its normal sequence-specific DNA-binding and transactivation function, but these mutations can also stabilize a mutant form of p53 with pro-oncogenic potential. Recent multi-disciplinary advances have demonstrated exciting and unexpected potential in therapeutically targeting the mutant p53 pathway, including: the development of biophysical models to explain how mutations inactivate p53 and strategies for refolding and reactivation of mutant p53, the ability of mutant p53 protein to escape MDM2-mediated degradation in human cancers, and the growing 'interactome' of mutant p53 that begins to explain how the mutant p53 protein can contribute to diverse oncogenic and pro-metastatic signaling. Our rapidly accumulating knowledge on mutant p53-signaling pathways will facilitate drug discovery programmes in the challenging area of protein-protein interactions and mutant protein conformational control.
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Affiliation(s)
- Magda M Maslon
- University of Edinburgh, Institute of Genetics and Molecular Medicine, Cell Signalling Unit, Cancer Research UK p53 Signal Transduction Group, Edinburgh EH4 2XR, UK
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Chen L, Li Z, Zwolinska AK, Smith MA, Cross B, Koomen J, Yuan ZM, Jenuwein T, Marine JC, Wright KL, Chen J. MDM2 recruitment of lysine methyltransferases regulates p53 transcriptional output. EMBO J 2010; 29:2538-52. [PMID: 20588255 DOI: 10.1038/emboj.2010.140] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2010] [Indexed: 11/10/2022] Open
Abstract
MDM2 is a key regulator of the p53 tumor suppressor acting primarily as an E3 ubiquitin ligase to promote its degradation. MDM2 also inhibits p53 transcriptional activity by recruiting histone deacetylase and corepressors to p53. Here, we show that immunopurified MDM2 complexes have significant histone H3-K9 methyltransferase activity. The histone methyltransferases SUV39H1 and EHMT1 bind specifically to MDM2 but not to its homolog MDMX. MDM2 mediates formation of p53-SUV39H1/EHMT1 complex capable of methylating H3-K9 in vitro and on p53 target promoters in vivo. Furthermore, MDM2 promotes EHMT1-mediated p53 methylation at K373. Knockdown of SUV39H1 and EHMT1 increases p53 activity during stress response without affecting p53 levels, whereas their overexpression inhibits p53 in an MDM2-dependent manner. The p53 activator ARF inhibits SUV39H1 and EHMT1 binding to MDM2 and reduces MDM2-associated methyltransferase activity. These results suggest that MDM2-dependent recruitment of methyltransferases is a novel mechanism of p53 regulation through methylation of both p53 itself and histone H3 at target promoters.
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Affiliation(s)
- Lihong Chen
- Molecular Oncology Department, Moffitt Cancer Center, Tampa, FL, USA
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Shi Y, Takenobu H, Kurata K, Yamaguchi Y, Yanagisawa R, Ohira M, Koike K, Nakagawara A, Jiang LL, Kamijo T. HDM2 impairs Noxa transcription and affects apoptotic cell death in a p53/p73-dependent manner in neuroblastoma. Eur J Cancer 2010; 46:2324-34. [PMID: 20591651 DOI: 10.1016/j.ejca.2010.05.026] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2010] [Revised: 05/17/2010] [Accepted: 05/24/2010] [Indexed: 11/20/2022]
Abstract
HDM2, a human homologue of MDM2, is a major negative regulator of p53 function, and increased expression of HDM2 by its promoter polymorphism SNP309 resulted in p53 inactivation and an increased risk of several tumours, including neuroblastoma (NB). Herein, we show that increased expression of HDM2 is related to a worse prognosis in MYCN-amplified NB patients. HDM2 plays an important role in the expression of Noxa, a pro-apoptotic molecule of the Bcl-2 family, which induces NB cell apoptotic death after doxorubcin (Doxo) treatment. Knockdown of HDM2 by siRNA resulted in the upregulation of Noxa at mRNA/protein levels and improved the sensitivity of Doxo-resistant NB cells, although these were not observed in p53-mutant NB cells. Noxa-knockdown abolished the recovered Doxo-induced cell death by HDM2 reduction. Intriguingly, resistance to Doxo was up-regulated by over-expression of HDM2 in Doxo-sensitive NB cells. By HDM2 expression, p53 was inactivated but its degradation was not accelerated, suggesting that p53 was degraded in a proteasome-independent manner in NB cells; downstream effectors of p53, p21(Cip1/Waf1) and Noxa were suppressed by HDM2. Noxa transcription was considerably regulated by both p53 and p73 in NB cells. Furthermore, in vivo binding of p53 and p73 to Noxa promoter was suppressed and Noxa promoter activation was inhibited by HDM2. Taken together, our results may indicate that the HDM2-related resistance to chemotherapeutic drugs of NB is regulated by p53/p73-dependent Noxa expression in NB.
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Affiliation(s)
- Yun Shi
- Division of Biochemistry and Molecular Carcinogenesis, Chiba Cancer Center Research Institute, 666-2 Nitona, Chuoh-ku, Chiba 260-8717, Japan
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Grochola LF, Zeron-Medina J, Mériaux S, Bond GL. Single-nucleotide polymorphisms in the p53 signaling pathway. Cold Spring Harb Perspect Biol 2010; 2:a001032. [PMID: 20452958 PMCID: PMC2857176 DOI: 10.1101/cshperspect.a001032] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The p53 tumor suppressor pathway is central both in reducing cancer frequency in vertebrates and in mediating the response of commonly used cancer therapies. This article aims to summarize and discuss a large body of evidence suggesting that the p53 pathway harbors functional inherited single-nucleotide polymorphisms (SNPs) that affect p53 signaling in cells, resulting in differences in cancer risk and clinical outcome in humans. The insights gained through these studies into how the functional p53 pathway SNPs could help in the tailoring of cancer therapies to the individual are discussed. Moreover, recent work is discussed that suggests that many more functional p53 pathway SNPs are yet to be fully characterized and that a thorough analysis of the functional human genetics of this important tumor suppressor pathway is required.
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Affiliation(s)
- Lukasz F Grochola
- Ludwig Institute for Cancer Research, University of Oxford, Oxford, OX3 7DQ, United Kingdom
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The Effects of Phosphomimetic Lid Mutation on the Thermostability of the N-terminal Domain of MDM2. J Mol Biol 2010; 398:414-28. [DOI: 10.1016/j.jmb.2010.03.023] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2010] [Revised: 03/11/2010] [Accepted: 03/11/2010] [Indexed: 12/21/2022]
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Abstract
Inactivation of p53 is critical for the formation of most tumors. Illumination of the key function(s) of p53 protein in protecting cells from becoming cancerous is therefore a worthy goal. Arguably p53's most important function is to act as a transcription factor that directly regulates perhaps several hundred of the cell's RNA polymerase II (RNAP II)-transcribed genes, and indirectly regulates thousands of others. Indeed p53 is the most well studied mammalian transcription factor. The p53 tetramer binds to its response element where it can recruit diverse transcriptional coregulators such as histone modifying enzymes, chromatin remodeling factors, subunits of the mediator complex, and components of general transcription machinery and preinitiation complex (PIC) to modulate RNAPII activity at target loci (Laptenko and Prives 2006). The p53 transcriptional program is regulated in a stimulus-specific fashion (Murray-Zmijewski et al. 2008; Vousden and Prives 2009), whereby distinct subsets of p53 target genes are induced in response to different p53-activating agents, likely allowing cells to tailor their response to different types of stress. How p53 is able to discriminate between these different loci is the subject of intense research. Here, we describe key aspects of the fundamentals of p53-mediated transcriptional regulation and target gene promoter selectivity.
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Affiliation(s)
- Rachel Beckerman
- Department of Biological Sciences, Columbia University, New York, New York 10027, USA
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