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Yin Q, Hu Y, Dong Z, Lu J, Wang H. Cellular, Structural Basis, and Recent Progress for Targeting Murine Double Minute X (MDMX) in Tumors. J Med Chem 2024. [PMID: 39185935 DOI: 10.1021/acs.jmedchem.4c00913] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/27/2024]
Abstract
Murine double minute X (MDMX) is an oncoprotein that mainly has a negative regulatory effect on the tumor suppressor p53 to induce tumorigenesis. As MDMX is highly expressed in various types of tumor cells, targeting and inhibiting MDMX are becoming a promising strategy for treating cancers. However, the high degree of structural homology between MDMX and its homologous protein murine double minute 2 (MDM2) is a great challenge for the development of MDMX-targeted therapies. This review introduces the structure, distribution, and regulation of the MDMX, summarizes the structural features and structure-activity relationships (SARs) of MDMX ligands, and focuses on the differences between MDMX and MDM2 in these aspects. Our purpose of this work is to propose potential strategies to achieve the specific targeting of MDMX.
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Affiliation(s)
- Qikun Yin
- School of Pharmacy, Key Laboratory of Molecular Pharmacology and Drug Evaluation (Yantai University), Ministry of Education, Collaborative Innovation Center of Advanced Drug Delivery System and Biotech Drugs in Universities of Shandong, Yantai University, Yantai 264005, China
| | - Yuemiao Hu
- School of Pharmacy, Key Laboratory of Molecular Pharmacology and Drug Evaluation (Yantai University), Ministry of Education, Collaborative Innovation Center of Advanced Drug Delivery System and Biotech Drugs in Universities of Shandong, Yantai University, Yantai 264005, China
| | - Zhiwen Dong
- School of Pharmacy, Key Laboratory of Molecular Pharmacology and Drug Evaluation (Yantai University), Ministry of Education, Collaborative Innovation Center of Advanced Drug Delivery System and Biotech Drugs in Universities of Shandong, Yantai University, Yantai 264005, China
| | - Jing Lu
- School of Pharmacy, Key Laboratory of Molecular Pharmacology and Drug Evaluation (Yantai University), Ministry of Education, Collaborative Innovation Center of Advanced Drug Delivery System and Biotech Drugs in Universities of Shandong, Yantai University, Yantai 264005, China
| | - Hongbo Wang
- School of Pharmacy, Key Laboratory of Molecular Pharmacology and Drug Evaluation (Yantai University), Ministry of Education, Collaborative Innovation Center of Advanced Drug Delivery System and Biotech Drugs in Universities of Shandong, Yantai University, Yantai 264005, China
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2
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Sterling NA, Cho SH, Kim S. Entosis implicates a new role for P53 in microcephaly pathogenesis, beyond apoptosis. Bioessays 2024; 46:e2300245. [PMID: 38778437 DOI: 10.1002/bies.202300245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Revised: 05/02/2024] [Accepted: 05/08/2024] [Indexed: 05/25/2024]
Abstract
Entosis, a form of cell cannibalism, is a newly discovered pathogenic mechanism leading to the development of small brains, termed microcephaly, in which P53 activation was found to play a major role. Microcephaly with entosis, found in Pals1 mutant mice, displays P53 activation that promotes entosis and apoptotic cell death. This previously unappreciated pathogenic mechanism represents a novel cellular dynamic in dividing cortical progenitors which is responsible for cell loss. To date, various recent models of microcephaly have bolstered the importance of P53 activation in cell death leading to microcephaly. P53 activation caused by mitotic delay or DNA damage manifests apoptotic cell death which can be suppressed by P53 removal in these animal models. Such genetic studies attest P53 activation as quality control meant to eliminate genomically unfit cells with minimal involvement in the actual function of microcephaly associated genes. In this review, we summarize the known role of P53 activation in a variety of microcephaly models and introduce a novel mechanism wherein entotic cell cannibalism in neural progenitors is triggered by P53 activation.
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Affiliation(s)
- Noelle A Sterling
- Shriners Hospitals Pediatric Research Center, Department of Neural Sciences, Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania, USA
- Biomedical Sciences Graduate Program, Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania, USA
| | - Seo-Hee Cho
- Center for Translational Medicine, Department of Medicine, Sydney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Seonhee Kim
- Shriners Hospitals Pediatric Research Center, Department of Neural Sciences, Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania, USA
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3
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Balasooriya ER, Madhusanka D, López-Palacios TP, Eastmond RJ, Jayatunge D, Owen JJ, Gashler JS, Egbert CM, Bulathsinghalage C, Liu L, Piccolo SR, Andersen JL. Integrating Clinical Cancer and PTM Proteomics Data Identifies a Mechanism of ACK1 Kinase Activation. Mol Cancer Res 2024; 22:137-151. [PMID: 37847650 PMCID: PMC10831333 DOI: 10.1158/1541-7786.mcr-23-0153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Revised: 08/17/2023] [Accepted: 10/13/2023] [Indexed: 10/19/2023]
Abstract
Beyond the most common oncogenes activated by mutation (mut-drivers), there likely exists a variety of low-frequency mut-drivers, each of which is a possible frontier for targeted therapy. To identify new and understudied mut-drivers, we developed a machine learning (ML) model that integrates curated clinical cancer data and posttranslational modification (PTM) proteomics databases. We applied the approach to 62,746 patient cancers spanning 84 cancer types and predicted 3,964 oncogenic mutations across 1,148 genes, many of which disrupt PTMs of known and unknown function. The list of putative mut-drivers includes established drivers and others with poorly understood roles in cancer. This ML model is available as a web application. As a case study, we focused the approach on nonreceptor tyrosine kinases (NRTK) and found a recurrent mutation in activated CDC42 kinase-1 (ACK1) that disrupts the Mig6 homology region (MHR) and ubiquitin-association (UBA) domains on the ACK1 C-terminus. By studying these domains in cultured cells, we found that disruption of the MHR domain helps activate the kinase while disruption of the UBA increases kinase stability by blocking its lysosomal degradation. This ACK1 mutation is analogous to lymphoma-associated mutations in its sister kinase, TNK1, which also disrupt a C-terminal inhibitory motif and UBA domain. This study establishes a mut-driver discovery tool for the research community and identifies a mechanism of ACK1 hyperactivation shared among ACK family kinases. IMPLICATIONS This research identifies a potentially targetable activating mutation in ACK1 and other possible oncogenic mutations, including PTM-disrupting mutations, for further study.
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Affiliation(s)
- Eranga R. Balasooriya
- The Fritz B. Burns Cancer Research Laboratory, Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah
- Center for Cancer Research, Massachusetts General Hospital, Boston, Massachusetts
- Dept. of Medicine, Harvard Medical School, Boston, Massachusetts
| | - Deshan Madhusanka
- The Fritz B. Burns Cancer Research Laboratory, Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah
- Department of Oncological Sciences and Huntsman Cancer Institute, University of Utah School of Medicine, Salt Lake City, Utah
| | - Tania P. López-Palacios
- The Fritz B. Burns Cancer Research Laboratory, Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah
- Department of Oncological Sciences and Huntsman Cancer Institute, University of Utah School of Medicine, Salt Lake City, Utah
| | - Riley J. Eastmond
- The Fritz B. Burns Cancer Research Laboratory, Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah
| | - Dasun Jayatunge
- The Fritz B. Burns Cancer Research Laboratory, Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah
- Department of Oncological Sciences and Huntsman Cancer Institute, University of Utah School of Medicine, Salt Lake City, Utah
| | - Jake J. Owen
- The Fritz B. Burns Cancer Research Laboratory, Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah
| | - Jack S. Gashler
- The Fritz B. Burns Cancer Research Laboratory, Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah
| | - Christina M. Egbert
- The Fritz B. Burns Cancer Research Laboratory, Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah
| | | | - Lu Liu
- Department of Computer Science, North Dakota State University, Fargo, North Dakota
| | | | - Joshua L. Andersen
- The Fritz B. Burns Cancer Research Laboratory, Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah
- Department of Oncological Sciences and Huntsman Cancer Institute, University of Utah School of Medicine, Salt Lake City, Utah
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4
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Fenton M, Borcherds W, Chen L, Anbanandam A, Levy R, Chen J, Daughdrill G. The MDMX Acidic Domain Uses Allovalency to Bind Both p53 and MDMX. J Mol Biol 2022; 434:167844. [PMID: 36181774 PMCID: PMC9644833 DOI: 10.1016/j.jmb.2022.167844] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 09/05/2022] [Accepted: 09/22/2022] [Indexed: 01/10/2023]
Abstract
Autoinhibition of p53 binding to MDMX requires two short-linear motifs (SLiMs) containing adjacent tryptophan (WW) and tryptophan-phenylalanine (WF) residues. NMR spectroscopy was used to show the WW and WF motifs directly compete for the p53 binding site on MDMX and circular dichroism spectroscopy was used to show the WW motif becomes helical when it is bound to the p53 binding domain (p53BD) of MDMX. Binding studies using isothermal titration calorimetry showed the WW motif is a stronger inhibitor of p53 binding than the WF motif when they are both tethered to p53BD by the natural disordered linker. We also investigated how the WW and WF motifs interact with the DNA binding domain (DBD) of p53. Both motifs bind independently to similar sites on DBD that overlap the DNA binding site. Taken together our work defines a model for complex formation between MDMX and p53 where a pair of disordered SLiMs bind overlapping sites on both proteins.
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Affiliation(s)
- Malissa Fenton
- Department of Cell Biology, Microbiology, and Molecular Biology, University of South Florida, Tampa, FL 33620, United States
| | - Wade Borcherds
- Department of Cell Biology, Microbiology, and Molecular Biology, University of South Florida, Tampa, FL 33620, United States
| | - Lihong Chen
- Molecular Oncology Department, Moffitt Cancer Center, Tampa, FL 33612, United States
| | - Asokan Anbanandam
- Department of Cell Biology, Microbiology, and Molecular Biology, University of South Florida, Tampa, FL 33620, United States
| | - Robin Levy
- Department of Cell Biology, Microbiology, and Molecular Biology, University of South Florida, Tampa, FL 33620, United States
| | - Jiandong Chen
- Molecular Oncology Department, Moffitt Cancer Center, Tampa, FL 33612, United States
| | - Gary Daughdrill
- Department of Cell Biology, Microbiology, and Molecular Biology, University of South Florida, Tampa, FL 33620, United States.
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5
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Srdanović S, Wolter M, Trinh CH, Ottmann C, Warriner SL, Wilson AJ. Understanding the interaction of 14-3-3 proteins with hDMX and hDM2: a structural and biophysical study. FEBS J 2022; 289:5341-5358. [PMID: 35286747 PMCID: PMC9541495 DOI: 10.1111/febs.16433] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 02/11/2022] [Accepted: 03/11/2022] [Indexed: 01/06/2023]
Abstract
p53 plays a critical role in regulating diverse biological processes: DNA repair, cell cycle arrest, apoptosis and senescence. The p53 pathway has therefore served as the focus of multiple drug-discovery efforts. p53 is negatively regulated by hDMX and hDM2; prior studies have identified 14-3-3 proteins as hDMX and hDM2 client proteins. 14-3-3 proteins are adaptor proteins that modulate localization, degradation and interactions of their targets in response to phosphorylation. Thus, 14-3-3 proteins may indirectly modulate the interaction between hDMX or hDM2 and p53 and represent potential targets for modulation of the p53 pathway. In this manuscript, we report on the biophysical and structural characterization of peptide/protein interactions that are representative of the interaction between 14-3-3 and hDMX or hDM2. The data establish that proximal phosphosites spaced ~20-25 residues apart in both hDMX and hDM2 co-operate to facilitate high-affinity 14-3-3 binding and provide structural insight that can be utilized in future stabilizer/inhibitor discovery efforts.
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Affiliation(s)
- Sonja Srdanović
- Astbury Centre for Structural Molecular BiologyUniversity of LeedsUK,School of ChemistryUniversity of LeedsUK
| | - Madita Wolter
- Laboratory of Chemical BiologyDepartment of Biomedical EngineeringTechnische Universiteit EindhovenThe Netherlands,Institute for Complex Molecular SystemsTechnische Universiteit EindhovenThe Netherlands
| | - Chi H. Trinh
- Astbury Centre for Structural Molecular BiologyUniversity of LeedsUK,School of Molecular and Cellular BiologyUniversity of LeedsUK
| | - Christian Ottmann
- Laboratory of Chemical BiologyDepartment of Biomedical EngineeringTechnische Universiteit EindhovenThe Netherlands,Institute for Complex Molecular SystemsTechnische Universiteit EindhovenThe Netherlands
| | - Stuart L. Warriner
- Astbury Centre for Structural Molecular BiologyUniversity of LeedsUK,School of ChemistryUniversity of LeedsUK
| | - Andrew J. Wilson
- Astbury Centre for Structural Molecular BiologyUniversity of LeedsUK,School of ChemistryUniversity of LeedsUK
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6
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Kowalczyk D, Nakasone MA, Smith BO, Huang DT. Bivalent binding of p14ARF to MDM2 RING and acidic domains inhibits E3 ligase function. Life Sci Alliance 2022; 5:e202201472. [PMID: 35944929 PMCID: PMC9366199 DOI: 10.26508/lsa.202201472] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 07/19/2022] [Accepted: 07/19/2022] [Indexed: 12/29/2022] Open
Abstract
ARF tumor suppressor protein is a key regulator of the MDM2-p53 signaling axis. ARF interferes with MDM2-mediated ubiquitination and degradation of p53 by sequestering MDM2 in the nucleolus and preventing MDM2-p53 interaction and nuclear export of p53. Moreover, ARF also directly inhibits MDM2 ubiquitin ligase (E3) activity, but the mechanism remains elusive. Here, we apply nuclear magnetic resonance and biochemical analyses to uncover the mechanism of ARF-mediated inhibition of MDM2 E3 activity. We show that MDM2 acidic and zinc finger domains (AD-ZnF) form a weak intramolecular interaction with the RING domain, where the binding site overlaps with the E2∼ubiquitin binding surface and thereby partially reduces MDM2 E3 activity. Binding of human N-terminal 32 residues of p14ARF to the acidic domain of MDM2 strengthens the AD-ZnF-RING domain interaction. Furthermore, the N-terminal RxFxV motifs of p14ARF participate directly in the MDM2 RING domain interaction. This bivalent binding mode of p14ARF to MDM2 acidic and RING domains restricts E2∼ubiquitin recruitment and massively hinders MDM2 E3 activity. These findings elucidate the mechanism by which ARF inhibits MDM2 E3 activity.
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Affiliation(s)
| | | | - Brian O Smith
- Institute of Molecular Cell and System Biology, University of Glasgow, Glasgow, UK
| | - Danny T Huang
- Cancer Research UK Beatson Institute, Glasgow, UK
- School of Cancer Sciences, University of Glasgow, Glasgow, UK
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7
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Floris M, Pira G, Castiglia P, Idda M, Steri M, De Miglio M, Piana A, Cossu A, Azara A, Arru C, Deiana G, Putzu C, Sanna V, Carru C, Serra A, Bisail M, Muroni M. Impact on breast cancer susceptibility and clinicopathological traits of common genetic polymorphisms in TP53, MDM2 and ATM genes in Sardinian women. Oncol Lett 2022; 24:331. [PMID: 36039053 PMCID: PMC9404703 DOI: 10.3892/ol.2022.13451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Accepted: 06/22/2022] [Indexed: 11/06/2022] Open
Abstract
Common variants of genes involved in DNA damage correction [tumor protein p53 (TP53), murine double 2 homolog oncoprotein (MDM2) and ataxia-telengiectasia mutated (ATM)] may serve a role in cancer predisposition. The purpose of the present study was to investigate the association of five variants in these genes with breast cancer risk and clinicopathological traits in a cohort of 261 women from northern Sardinia. Polymorphic variants in TP53 (rs17878362, rs1042522 and rs1625895), MDM2 (rs2279744) and ATM (rs1799757) were determined by PCR and TaqMan single nucleotide polymorphism assay in patients with breast cancer (n=136) and healthy controls (n=125). Association with clinicopathological (e.g., age at diagnosis, lymph node involvement, clinical stage) and lifestyle factors (e.g., smoking status, alcohol intake, contraceptive use) was also evaluated. TP53 rs17878362 and rs1625895 polymorphisms were associated with decreased risk of BC diagnosis in patients older than 50 years (codominant and recessive models) and post-menopause (recessive model). Furthermore, there was a significant association between lymph node status (positive vs. negative) and ATM rs1799757-delT in dominant and additive models and between MDM2 rs2279744-allele and use of oral contraceptives. This analysis suggested that TP53 rs17878362 and rs1625895 may affect age of onset of breast cancer and ATM rs1799757 and MDM2 rs2279744 may be associated with lymph node status and prolonged use of oral contraceptives, respectively.
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Affiliation(s)
- Matteo Floris
- Department of Biomedical Sciences, Surgery and Pharmacy, University of Sassari, Sassari, I-07100 Sardinia, Italy
| | - Giovanna Pira
- Department of Biomedical Sciences, Surgery and Pharmacy, University of Sassari, Sassari, I-07100 Sardinia, Italy
| | - Paolo Castiglia
- Department of Medicine, Surgery and Pharmacy, University of Sassari, Sassari, I-07100 Sardinia, Italy
| | - Maria Idda
- Institute for Genetic and Biomedical Research, National Research Council, Monserrato, Cagliari, I-09121 Sardinia, Italy
| | - Maristella Steri
- Institute for Genetic and Biomedical Research, National Research Council, Monserrato, Cagliari, I-09121 Sardinia, Italy
| | - Maria De Miglio
- Department of Medicine, Surgery and Pharmacy, University of Sassari, Sassari, I-07100 Sardinia, Italy
| | - Andrea Piana
- Department of Medicine, Surgery and Pharmacy, University of Sassari, Sassari, I-07100 Sardinia, Italy
| | - Andrea Cossu
- Department of Medicine, Surgery and Pharmacy, University of Sassari, Sassari, I-07100 Sardinia, Italy
| | - Antonio Azara
- Department of Medicine, Surgery and Pharmacy, University of Sassari, Sassari, I-07100 Sardinia, Italy
| | - Caterina Arru
- Department of Biomedical Sciences, Surgery and Pharmacy, University of Sassari, Sassari, I-07100 Sardinia, Italy
| | - Giovanna Deiana
- Department of Biomedical Sciences, Surgery and Pharmacy, University of Sassari, Sassari, I-07100 Sardinia, Italy
| | - Carlo Putzu
- Division of Medical Oncology, Azienda Ospedaliera Universitaria, Sassari, I-07100 Sardinia, Italy
| | - Valeria Sanna
- Division of Medical Oncology, Azienda Ospedaliera Universitaria, Sassari, I-07100 Sardinia, Italy
| | - Ciriaco Carru
- Department of Biomedical Sciences, Surgery and Pharmacy, University of Sassari, Sassari, I-07100 Sardinia, Italy
| | - Antonello Serra
- Unit of Occupational Medicine, Azienda Ospedaliera Universitaria, Sassari, I-07100 Sardinia, Italy
| | - Marco Bisail
- Lega Italiana per la Lotta contro i Tumori, Sassari, I-07100 Sardinia, Italy
| | - Maria Muroni
- Institute for Genetic and Biomedical Research, National Research Council, Monserrato, Cagliari, I-09121 Sardinia, Italy
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8
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Zhang C, Xu H, Sui X, Chen L, Chen B, Lv H, Wang S, Wang X. Icaritin inhibits PLK1 to activate DNA damage response in NK/T cell lymphoma and increases sensitivity to GELOX regime. Mol Ther Oncolytics 2022; 25:288-304. [PMID: 35663228 PMCID: PMC9127125 DOI: 10.1016/j.omto.2022.04.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Accepted: 04/29/2022] [Indexed: 02/07/2023] Open
Abstract
Natural killer/T cell lymphoma (NKTCL) is a highly aggressive subtype of non-Hodgkin lymphoma. Gemcitabine, oxaliplatin, and L-asparaginase (GELOX) is one of the first-line chemotherapy regimens of NKTCL. Yet, the prognosis of NKTCL is poor. Icaritin is an herb-derived monomer from icariin with antitumor effects. We found that icaritin induced proliferation inhibition and apoptosis of NKTCL both in vitro and in vivo. Moreover, icaritin inhibited the dissemination of NKTCL in vivo. RNA sequencing revealed the Polo-like kinase 1 (PLK1) gene and DNA damage response (DDR) as the targets of icaritin. Mechanistically, icaritin inhibited PLK1 to promote checkpoint kinase 2 (Chk2) homodimerization and its T387 phosphorylation, which further activated p53, leading to the activation of the DDR pathway. Moreover, inhibiting PLK1 increased Forkhead box O3a nuclear localization, the latter of which activated ataxia telangiectasia mutated (ATM), an early sensor of DNA damage. Then ATM phosphorylated Chk2 T68 and initiated Chk2 activation. Remarkably, the combined treatment of icaritin and GELOX achieved better antitumor efficacy than single treatment in vivo. In summary, our results proved the efficacy of icaritin treating NKTCL, provided insights into its antitumor molecular mechanism, and revealed the application value of icaritin in facilitating clinical NKTCL treatment.
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Affiliation(s)
- Canjing Zhang
- Key Laboratory of Medical Molecular Virology of Ministry of Education & Ministry of Health, School of Basic Medical Sciences and Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, People's Republic of China.,Laboratory of Medical Molecular Biology, Experimental Teaching Center, School of Basic Medical Sciences, Fudan University, Shanghai 200032, People's Republic of China
| | - Huiwen Xu
- Key Laboratory of Medical Molecular Virology of Ministry of Education & Ministry of Health, School of Basic Medical Sciences and Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, People's Republic of China.,Department of Hematology, Huashan Hospital, Fudan University, Shanghai 200040, People's Republic of China
| | - Xianxian Sui
- Laboratory of Medical Molecular Biology, Experimental Teaching Center, School of Basic Medical Sciences, Fudan University, Shanghai 200032, People's Republic of China
| | - Lina Chen
- Key Laboratory of Medical Molecular Virology of Ministry of Education & Ministry of Health, School of Basic Medical Sciences and Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, People's Republic of China
| | - Bobin Chen
- Department of Hematology, Huashan Hospital, Fudan University, Shanghai 200040, People's Republic of China
| | - Haozhen Lv
- Shanghai Medical College, Fudan University, Shanghai 200032, People's Republic of China
| | - Songmei Wang
- Laboratory of Medical Molecular Biology, Experimental Teaching Center, School of Basic Medical Sciences, Fudan University, Shanghai 200032, People's Republic of China
| | - Xuanyi Wang
- Key Laboratory of Medical Molecular Virology of Ministry of Education & Ministry of Health, School of Basic Medical Sciences and Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, People's Republic of China
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9
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Cryptic in vitro ubiquitin ligase activity of HDMX towards p53 is likely regulated by an induced fit mechanism. Biosci Rep 2022; 42:231398. [PMID: 35674210 PMCID: PMC9254666 DOI: 10.1042/bsr20220186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Revised: 05/29/2022] [Accepted: 05/31/2022] [Indexed: 11/17/2022] Open
Abstract
HDMX and its homologue HDM2 are two essential proteins for the cell; after genotoxic stress, both are phosphorylated near to their RING domain, specifically at serine 403 and 395, respectively. Once phosphorylated, both can bind the p53 mRNA and enhance its translation; however, both recognise p53 protein and provoke its degradation under normal conditions. HDM2 has been well-recognised as an E3 ubiquitin ligase, whereas it has been reported that even with the high similarity between the RING domains of the two homologs, HDMX does not have the E3 ligase activity. Despite this, HDMX is needed for the proper p53 poly-ubiquitination. Phosphorylation at serine 395 changes the conformation of HDM2, helping to explain the switch in its activity, but no information on HDMX has been published. Here we study the conformation of HDMX and its phospho-mimetic mutant S403D, investigate its E3 ligase activity and dissect its binding with p53. We show that phospho-mutation does not change the conformation of the protein, but HDMX is indeed an E3 ubiquitin ligase in vitro; however, in vivo, no activity was found. We speculated that HDMX is regulated by induced fit, being able to switch activity accordingly to the specific partner as p53 protein, p53 mRNA or HDM2. Our results aim to contribute to the elucidation of the contribution of the HDMX to p53 regulation.
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10
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Czajkowski D, Szmyd R, Gee HE. Impact of DNA damage response defects in cancer cells on response to immunotherapy and radiotherapy. J Med Imaging Radiat Oncol 2022; 66:546-559. [PMID: 35460184 PMCID: PMC9321602 DOI: 10.1111/1754-9485.13413] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 04/03/2022] [Accepted: 04/06/2022] [Indexed: 11/30/2022]
Abstract
The DNA damage response (DDR) is a complex set of downstream pathways triggered in response to DNA damage to maintain genomic stability. Many tumours exhibit mutations which inactivate components of the DDR, making them prone to the accumulation of DNA defects. These can both facilitate the development of tumours and provide potential targets for novel therapeutic interventions. The inhibition of the DDR has been shown to induce radiosensitivity in certain cancers, rendering them susceptible to treatment with radiotherapy and improving the therapeutic window. Moreover, DDR defects are a strong predictor of patient response to immune checkpoint inhibition (ICI). The ability to target the DDR selectively has the potential to expand the tumour neoantigen repertoire, thus increasing tumour immunogenicity and facilitating a CD8+ T and NK cell response against cancer cells. Combinatorial approaches, which seek to integrate DDR inhibition with radiotherapy and immunotherapy, have shown promise in early trials. Further studies are necessary to understand these synergies and establish reliable biomarkers.
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Affiliation(s)
| | - Radosław Szmyd
- Genome Integrity Unit, Children's Medical Research Institute, University of Sydney, Sydney, New South Wales, Australia.,Sydney West Radiation Oncology Network, Crown Princess Mary Cancer Centre Westmead, Sydney, New South Wales, Australia
| | - Harriet E Gee
- University of Sydney, Sydney, New South Wales, Australia.,Genome Integrity Unit, Children's Medical Research Institute, University of Sydney, Sydney, New South Wales, Australia.,Sydney West Radiation Oncology Network, Crown Princess Mary Cancer Centre Westmead, Sydney, New South Wales, Australia
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11
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Li Z, Li S, Luo M, Jhong JH, Li W, Yao L, Pang Y, Wang Z, Wang R, Ma R, Yu J, Huang Y, Zhu X, Cheng Q, Feng H, Zhang J, Wang C, Hsu JBK, Chang WC, Wei FX, Huang HD, Lee TY. dbPTM in 2022: an updated database for exploring regulatory networks and functional associations of protein post-translational modifications. Nucleic Acids Res 2021; 50:D471-D479. [PMID: 34788852 PMCID: PMC8728263 DOI: 10.1093/nar/gkab1017] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 10/08/2021] [Accepted: 10/13/2021] [Indexed: 01/02/2023] Open
Abstract
Protein post-translational modifications (PTMs) play an important role in different cellular processes. In view of the importance of PTMs in cellular functions and the massive data accumulated by the rapid development of mass spectrometry (MS)-based proteomics, this paper presents an update of dbPTM with over 2 777 000 PTM substrate sites obtained from existing databases and manual curation of literature, of which more than 2 235 000 entries are experimentally verified. This update has manually curated over 42 new modification types that were not included in the previous version. Due to the increasing number of studies on the mechanism of PTMs in the past few years, a great deal of upstream regulatory proteins of PTM substrate sites have been revealed. The updated dbPTM thus collates regulatory information from databases and literature, and merges them into a protein-protein interaction network. To enhance the understanding of the association between PTMs and molecular functions/cellular processes, the functional annotations of PTMs are curated and integrated into the database. In addition, the existing PTM-related resources, including annotation databases and prediction tools are also renewed. Overall, in this update, we would like to provide users with the most abundant data and comprehensive annotations on PTMs of proteins. The updated dbPTM is now freely accessible at https://awi.cuhk.edu.cn/dbPTM/.
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Affiliation(s)
- Zhongyan Li
- The Genetics Laboratory, Longgang District Maternity & Child Healthcare Hospital of Shenzhen City, Shenzhen 518172, China.,School of Life and Health Sciences, The Chinese University of Hong Kong, Shenzhen 518172, China.,Warshel Institute for Computational Biology, The Chinese University of Hong Kong, Shenzhen 518172, China
| | - Shangfu Li
- Warshel Institute for Computational Biology, The Chinese University of Hong Kong, Shenzhen 518172, China
| | - Mengqi Luo
- Warshel Institute for Computational Biology, The Chinese University of Hong Kong, Shenzhen 518172, China
| | - Jhih-Hua Jhong
- Warshel Institute for Computational Biology, The Chinese University of Hong Kong, Shenzhen 518172, China
| | - Wenshuo Li
- Warshel Institute for Computational Biology, The Chinese University of Hong Kong, Shenzhen 518172, China.,School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen 518172, China
| | - Lantian Yao
- Warshel Institute for Computational Biology, The Chinese University of Hong Kong, Shenzhen 518172, China.,School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen 518172, China
| | - Yuxuan Pang
- Warshel Institute for Computational Biology, The Chinese University of Hong Kong, Shenzhen 518172, China.,School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen 518172, China
| | - Zhuo Wang
- Warshel Institute for Computational Biology, The Chinese University of Hong Kong, Shenzhen 518172, China
| | - Rulan Wang
- Warshel Institute for Computational Biology, The Chinese University of Hong Kong, Shenzhen 518172, China.,School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen 518172, China
| | - Renfei Ma
- Warshel Institute for Computational Biology, The Chinese University of Hong Kong, Shenzhen 518172, China
| | - Jinhan Yu
- Warshel Institute for Computational Biology, The Chinese University of Hong Kong, Shenzhen 518172, China
| | - Yuqi Huang
- School of Life and Health Sciences, The Chinese University of Hong Kong, Shenzhen 518172, China.,Warshel Institute for Computational Biology, The Chinese University of Hong Kong, Shenzhen 518172, China
| | - Xiaoning Zhu
- School of Life and Health Sciences, The Chinese University of Hong Kong, Shenzhen 518172, China.,Warshel Institute for Computational Biology, The Chinese University of Hong Kong, Shenzhen 518172, China
| | - Qifan Cheng
- School of Life and Health Sciences, The Chinese University of Hong Kong, Shenzhen 518172, China.,Warshel Institute for Computational Biology, The Chinese University of Hong Kong, Shenzhen 518172, China
| | - Hexiang Feng
- School of Life and Health Sciences, The Chinese University of Hong Kong, Shenzhen 518172, China.,Warshel Institute for Computational Biology, The Chinese University of Hong Kong, Shenzhen 518172, China
| | - Jiahong Zhang
- School of Life and Health Sciences, The Chinese University of Hong Kong, Shenzhen 518172, China.,Warshel Institute for Computational Biology, The Chinese University of Hong Kong, Shenzhen 518172, China
| | - Chunxuan Wang
- School of Life and Health Sciences, The Chinese University of Hong Kong, Shenzhen 518172, China.,Warshel Institute for Computational Biology, The Chinese University of Hong Kong, Shenzhen 518172, China
| | - Justin Bo-Kai Hsu
- Department of Medical Research, Taipei Medical University Hospital, Taipei 110, Taiwan
| | - Wen-Chi Chang
- Institute of Tropical Plant Sciences and Microbiology, National Cheng Kung University, Tainan 701, Taiwan
| | - Feng-Xiang Wei
- The Genetics Laboratory, Longgang District Maternity & Child Healthcare Hospital of Shenzhen City, Shenzhen 518172, China.,Department of Cell Biology, Jiamusi University, Jiamusi 154007, China.,Shenzhen Children's Hospital of China Medical University, Shenzhen 518172, China
| | - Hsien-Da Huang
- The Genetics Laboratory, Longgang District Maternity & Child Healthcare Hospital of Shenzhen City, Shenzhen 518172, China.,School of Life and Health Sciences, The Chinese University of Hong Kong, Shenzhen 518172, China.,Warshel Institute for Computational Biology, The Chinese University of Hong Kong, Shenzhen 518172, China
| | - Tzong-Yi Lee
- School of Life and Health Sciences, The Chinese University of Hong Kong, Shenzhen 518172, China.,Warshel Institute for Computational Biology, The Chinese University of Hong Kong, Shenzhen 518172, China
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12
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MDM2, MDMX, and p73 regulate cell-cycle progression in the absence of wild-type p53. Proc Natl Acad Sci U S A 2021; 118:2102420118. [PMID: 34716260 DOI: 10.1073/pnas.2102420118] [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: 02/08/2021] [Accepted: 09/21/2021] [Indexed: 02/08/2023] Open
Abstract
The p53 tumor suppressor protein, known to be critically important in several processes including cell-cycle arrest and apoptosis, is highly regulated by multiple mechanisms, most certifiably the Murine Double Minute 2-Murine Double Minute X (MDM2-MDMX) heterodimer. The role of MDM2-MDMX in cell-cycle regulation through inhibition of p53 has been well established. Here we report that in cells either lacking p53 or expressing certain tumor-derived mutant forms of p53, loss of endogenous MDM2 or MDMX, or inhibition of E3 ligase activity of the heterocomplex, causes cell-cycle arrest. This arrest is correlated with a reduction in E2F1, E2F3, and p73 levels. Remarkably, direct ablation of endogenous p73 produces a similar effect on the cell cycle and the expression of certain E2F family members at both protein and messenger RNA levels. These data suggest that MDM2 and MDMX, working at least in part as a heterocomplex, may play a p53-independent role in maintaining cell-cycle progression by promoting the activity of E2F family members as well as p73, making them a potential target of interest in cancers lacking wild-type p53.
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13
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Sanford JD, Yang J, Han J, Tollini LA, Jin A, Zhang Y. MDMX is essential for the regulation of p53 protein levels in the absence of a functional MDM2 C-terminal tail. BMC Mol Cell Biol 2021; 22:46. [PMID: 34551723 PMCID: PMC8459461 DOI: 10.1186/s12860-021-00385-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Accepted: 08/20/2021] [Indexed: 01/21/2023] Open
Abstract
BACKGROUND MDM2 is an E3 ubiquitin ligase that is able to ubiquitinate p53, targeting it for proteasomal degradation. Its homologue MDMX does not have innate E3 activity, but is able to dimerize with MDM2. Although mouse models have demonstrated both MDM2 and MDMX are individually essential for p53 regulation, the significance of MDM2-MDMX heterodimerization is only partially understood and sometimes controversial. MDM2C462A mice, where the C462A mutation abolishes MDM2 E3 ligase activity as well as its ability to dimerize with MDMX, die during embryogenesis. In contrast, the MDM2Y487A mice, where the Y487A mutation at MDM2 C-terminus significantly reduces its E3 ligase activity without disrupting MDM2-MDMX binding, survive normally even though p53 is expressed to high levels. This indicates that the MDM2-MDMX heterodimerization plays a critical role in the regulation of p53. However, it remains unclear whether MDMX is essential for the regulation of p53 protein levels in the context of an endogenous MDM2 C-terminal tail mutation. RESULTS Here, we studied the significance of MDM2-MDMX binding in an MDM2 E3 ligase deficient context using the MDM2Y487A mouse embryonic fibroblast (MEF) cells. Surprisingly, down-regulation of MDMX in MDM2Y487A MEFs resulted in a significant increase of p53 protein levels. Conversely, ectopic overexpression of MDMX reduced p53 protein levels in MDM2Y487A MEFs. Mutations of the RING domain of MDMX prevented MDMX-MDM2 binding, and ablated MDMX-mediated suppression of p53 protein expression. Additionally, DNA damage treatment and nuclear sequestration of MDMX inhibited MDMX activity to suppress p53 protein expression. CONCLUSIONS These results suggest that MDMX plays a key role in suppressing p53 protein expression in the absence of normal MDM2 E3 ligase activity. We found that the ability of MDMX to suppress p53 levels requires MDM2 binding and its cytoplasmic localization, and this ability is abrogated by DNA damage. Hence, MDMX is essential for the regulation of p53 protein levels in the context of an MDM2 C-terminal mutation that disrupts its E3 ligase activity but not MDMX binding. Our study is the first to examine the role of MDMX in the regulation of p53 in the context of endogenous MDM2 C-terminal mutant MEF cells.
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Affiliation(s)
- Jack D Sanford
- Department of Radiation Oncology, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27514, USA
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27514, USA
- Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27514, USA
| | - Jing Yang
- Department of Radiation Oncology, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27514, USA
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27514, USA
- Jiangsu Province Key Laboratory of Immunity and Metabolism and Department of Pathogenic Biology and Immunology, Xuzhou Medical University, Xuzhou, 221002, Jiangsu, China
| | - Jing Han
- Department of Radiation Oncology, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27514, USA
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27514, USA
- Jiangsu Province Key Laboratory of Immunity and Metabolism and Department of Pathogenic Biology and Immunology, Xuzhou Medical University, Xuzhou, 221002, Jiangsu, China
| | - Laura A Tollini
- Department of Radiation Oncology, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27514, USA
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27514, USA
- Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27514, USA
| | - Aiwen Jin
- Department of Radiation Oncology, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27514, USA
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27514, USA
| | - Yanping Zhang
- Department of Radiation Oncology, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27514, USA.
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27514, USA.
- Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27514, USA.
- Department of Pharmacology, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27514, USA.
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14
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Checker R, Patwardhan RS, Jayakumar S, Maurya DK, Bandekar M, Sharma D, Sandur SK. Chemical and biological basis for development of novel radioprotective drugs for cancer therapy. Free Radic Res 2021; 55:595-625. [PMID: 34181503 DOI: 10.1080/10715762.2021.1876854] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Ionizing radiation (IR) causes chemical changes in biological systems through direct interaction with the macromolecules or by causing radiolysis of water. This property of IR is harnessed in the clinic for radiotherapy in almost 50% of cancers patients. Despite the advent of stereotactic radiotherapy instruments and other advancements in shielding techniques, the inadvertent deposition of radiation dose in the surrounding normal tissue can cause late effects of radiation injury in normal tissues. Radioprotectors, which are chemical or biological agents, can reduce or mitigate these toxic side-effects of radiotherapy in cancer patients and also during radiation accidents. The desired characteristics of an ideal radioprotector include low chemical toxicity, high risk to benefit ratio and specific protection of normal cells against the harmful effects of radiation without compromising the cytotoxic effects of IR on cancer cells. Since reactive oxygen species (ROS) are the major contributors of IR mediated toxicity, plethora of studies have highlighted the potential role of antioxidants to protect against IR induced damage. However, owing to the lack of any clinically approved radioprotector against whole body radiation, researchers have shifted the focus toward finding alternate targets that could be exploited for the development of novel agents. The present review provides a comprehensive insight in to the different strategies, encompassing prime molecular targets, which have been employed to develop radiation protectors/countermeasures. It is anticipated that understanding such factors will lead to the development of novel strategies for increasing the outcome of radiotherapy by minimizing normal tissue toxicity.
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Affiliation(s)
- Rahul Checker
- Radiation Biology & Health Sciences Division, Bio-science Group, Bhabha Atomic Research Centre, Mumbai, India.,Homi Bhabha National Institute, Anushaktinagar, Mumbai, India
| | - Raghavendra S Patwardhan
- Radiation Biology & Health Sciences Division, Bio-science Group, Bhabha Atomic Research Centre, Mumbai, India.,Homi Bhabha National Institute, Anushaktinagar, Mumbai, India
| | - Sundarraj Jayakumar
- Radiation Biology & Health Sciences Division, Bio-science Group, Bhabha Atomic Research Centre, Mumbai, India
| | - Dharmendra Kumar Maurya
- Radiation Biology & Health Sciences Division, Bio-science Group, Bhabha Atomic Research Centre, Mumbai, India.,Homi Bhabha National Institute, Anushaktinagar, Mumbai, India
| | - Mayuri Bandekar
- Radiation Biology & Health Sciences Division, Bio-science Group, Bhabha Atomic Research Centre, Mumbai, India
| | - Deepak Sharma
- Radiation Biology & Health Sciences Division, Bio-science Group, Bhabha Atomic Research Centre, Mumbai, India.,Homi Bhabha National Institute, Anushaktinagar, Mumbai, India
| | - Santosh K Sandur
- Radiation Biology & Health Sciences Division, Bio-science Group, Bhabha Atomic Research Centre, Mumbai, India.,Homi Bhabha National Institute, Anushaktinagar, Mumbai, India
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15
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Role of Dietary Antioxidants in p53-Mediated Cancer Chemoprevention and Tumor Suppression. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2021; 2021:9924328. [PMID: 34257824 PMCID: PMC8257365 DOI: 10.1155/2021/9924328] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Accepted: 05/31/2021] [Indexed: 02/07/2023]
Abstract
Cancer arises through a complex interplay between genetic, behavioral, metabolic, and environmental factors that combined trigger cellular changes that over time promote malignancy. In terms of cancer prevention, behavioral interventions such as diet can promote genetic programs that may facilitate tumor suppression; and one of the key tumor suppressors responsible for initiating such programs is p53. The p53 protein is activated by various cellular events such as DNA damage, hypoxia, heat shock, and overexpression of oncogenes. Due to its role in cell fate decisions after DNA damage, regulatory pathways controlled by p53 help to maintain genome stability and thus “guard the genome” against mutations that cause cancer. Dietary intake of flavonoids, a C15 group of polyphenols, is known to inhibit cancer progression and assist DNA repair through p53-mediated mechanisms in human cells via their antioxidant activities. For example, quercetin arrests human cervical cancer cell growth by blocking the G2/M phase cell cycle and inducing mitochondrial apoptosis through a p53-dependent mechanism. Other polyphenols such as resveratrol upregulate p53 expression in several cancer cell lines by promoting p53 stability, which in colon cancer cells results in the activation of p53-mediated apoptosis. Finally, among vitamins, folic acid seems to play an important role in the chemoprevention of gastric carcinogenesis by enhancing gastric epithelial apoptosis in patients with premalignant lesions by significantly increased expression of p53. In this review, we discuss the role of these and other dietary antioxidants in p53-mediated cell signaling in relation to cancer chemoprevention and tumor suppression in normal and cancer cells.
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16
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Timmerman DM, Remmers TL, Hillenius S, Looijenga LHJ. Mechanisms of TP53 Pathway Inactivation in Embryonic and Somatic Cells-Relevance for Understanding (Germ Cell) Tumorigenesis. Int J Mol Sci 2021; 22:ijms22105377. [PMID: 34065345 PMCID: PMC8161298 DOI: 10.3390/ijms22105377] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 05/14/2021] [Accepted: 05/15/2021] [Indexed: 01/10/2023] Open
Abstract
The P53 pathway is the most important cellular pathway to maintain genomic and cellular integrity, both in embryonic and non-embryonic cells. Stress signals induce its activation, initiating autophagy or cell cycle arrest to enable DNA repair. The persistence of these signals causes either senescence or apoptosis. Over 50% of all solid tumors harbor mutations in TP53 that inactivate the pathway. The remaining cancers are suggested to harbor mutations in genes that regulate the P53 pathway such as its inhibitors Mouse Double Minute 2 and 4 (MDM2 and MDM4, respectively). Many reviews have already been dedicated to P53, MDM2, and MDM4, while this review additionally focuses on the other factors that can deregulate P53 signaling. We discuss that P14ARF (ARF) functions as a negative regulator of MDM2, explaining the frequent loss of ARF detected in cancers. The long non-coding RNA Antisense Non-coding RNA in the INK4 Locus (ANRIL) is encoded on the same locus as ARF, inhibiting ARF expression, thus contributing to the process of tumorigenesis. Mutations in tripartite motif (TRIM) proteins deregulate P53 signaling through their ubiquitin ligase activity. Several microRNAs (miRNAs) inactivate the P53 pathway through inhibition of translation. CCCTC-binding factor (CTCF) maintains an open chromatin structure at the TP53 locus, explaining its inactivation of CTCF during tumorigenesis. P21, a downstream effector of P53, has been found to be deregulated in different tumor types. This review provides a comprehensive overview of these factors that are known to deregulate the P53 pathway in both somatic and embryonic cells, as well as their malignant counterparts (i.e., somatic and germ cell tumors). It provides insights into which aspects still need to be unraveled to grasp their contribution to tumorigenesis, putatively leading to novel targets for effective cancer therapies.
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17
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Kilarkaje N, Al-Qaryyan M, Al-Bader MD. Trans-resveratrol imparts disparate effects on transcription of DNA damage sensing/repair pathway genes in euglycemic and hyperglycemic rat testis. Toxicol Appl Pharmacol 2021; 418:115510. [PMID: 33775663 DOI: 10.1016/j.taap.2021.115510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 03/12/2021] [Accepted: 03/23/2021] [Indexed: 11/25/2022]
Abstract
Prevention or repair of DNA damage is critical to inhibit carcinogenesis in living organisms. Using quantitative RT2 Profiler™ PCR array, we investigated if trans-resveratrol could modulate the transcription of DNA damage sensing/repair pathway genes in euglycemic and non-obese type 2 diabetic Goto-Kakizaki rat testis. Trans-resveratrol imparted disparate effects on gene expressions. In euglycemic rats, it downregulated 79% and upregulated 2% of genes. However, in diabetic rats, it upregulated only 2% and downregulated 4% of genes. As such, diabetes upregulated 16% and downregulated 4% of genes. Trans-resveratrol normalized the expression of 9 (60%) out of 15 upregulated genes in diabetic rats. In euglycemic rats, trans-resveratrol inhibited ATM/ATR, DNA damage repair, pro-cell cycle progression, and apoptosis signaling genes. However, it increased Cdkn1a and Sumo1, indicating cell cycle arrest, apoptosis, and cytostasis in conjunction with increased DNA double-strand breaks and apoptosis. Diabetes increased DNA damage and apoptosis but did not affect ATM/ATR and double-strand break repair genes, although it increased few single-strand repair genes. Diabetes increased Abl1 and Sirt1, which may be related to apoptosis, but their increase may well suggest the enhanced cell cycle progression and putative carcinogenicity. The transcription of Rad17 and Smc1a increased in diabetic rats indicating G2 phase arrest and increases in a few DNA single-strand breaks repair genes suggesting DNA damage repair. Trans-resveratrol inhibits the cell cycle and causes cell death in euglycemic rat testis but normalizes diabetes-induced genes related to DNA damage and cell cycle control, suggesting its usefulness in maintaining DNA integrity in diabetes.
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Affiliation(s)
| | - Mariam Al-Qaryyan
- Department of Physiology Faculty of Medicine, Kuwait University, Kuwait
| | - Maie D Al-Bader
- Department of Physiology Faculty of Medicine, Kuwait University, Kuwait
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18
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He Y, Yin X, Dong J, Yang Q, Wu Y, Gong Z. Transcriptome Analysis of Caco-2 Cells upon the Exposure of Mycotoxin Deoxynivalenol and Its Acetylated Derivatives. Toxins (Basel) 2021; 13:167. [PMID: 33671637 PMCID: PMC7927021 DOI: 10.3390/toxins13020167] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Revised: 02/16/2021] [Accepted: 02/19/2021] [Indexed: 11/17/2022] Open
Abstract
Deoxynivalenol (DON), 3-acetyldeoxynivalenol (3-ADON) and 15-acetyldeoxynivalenol (15-ADON) are type B trichothecenes; one of the major pollutants in food and feed products. Although the toxicity of DON has been well documented, information on the toxicity of its acetylated derivative remains incomplete. To acquire more detailed insight into 3-ADON and 15-ADON, Caco-2 cells under 0.5 µM DON, 3-ADON and 15-ADON treatment for 24 h were subjected to RNA-seq analysis. In the present study, 2656, 3132 and 2425 differentially expressed genes (DEGs) were selected, respectively, and were enriched utilizing the Kyoto Encyclopedia of Genes and Genomes (KEGG) and the Gene Ontology (GO) database. The upregulation of ataxia-telangiectasia mutated kinase (ATM), WEE1 homolog 2 (WEE2) and downregulation of proliferating cell nuclear antigen (PCNA), minichromosome maintenance (MCMs), cyclin dependent kinase (CDKs), and E2Fs indicate that the three toxins induced DNA damage, inhibition of DNA replication and cell cycle arrest in Caco-2 cells. Additionally, the upregulation of sestrin (SENEs) and NEIL1 implied that the reason for DNA damage may be attributable to oxidative stress. Our study provides insight into the toxic mechanism of 3-ADON and 15-ADON.
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Affiliation(s)
- Yuyun He
- Key Laboratory for Deep Processing of Major Grain and Oil of Ministry of Education, Wuhan Polytechnic University, Wuhan 430023, China; (Y.H.); (X.Y.); (J.D.); (Q.Y.)
| | - Xiaoyao Yin
- Key Laboratory for Deep Processing of Major Grain and Oil of Ministry of Education, Wuhan Polytechnic University, Wuhan 430023, China; (Y.H.); (X.Y.); (J.D.); (Q.Y.)
| | - Jingjing Dong
- Key Laboratory for Deep Processing of Major Grain and Oil of Ministry of Education, Wuhan Polytechnic University, Wuhan 430023, China; (Y.H.); (X.Y.); (J.D.); (Q.Y.)
| | - Qing Yang
- Key Laboratory for Deep Processing of Major Grain and Oil of Ministry of Education, Wuhan Polytechnic University, Wuhan 430023, China; (Y.H.); (X.Y.); (J.D.); (Q.Y.)
| | - Yongning Wu
- China National Center for Food Safety Risk Assessment, NHC Key Laboratory of Food Safety Risk Assessment, Food Safety Research Unit (2019RU014) of Chinese Academy of Medical Science, Beijing 100000, China;
| | - Zhiyong Gong
- Key Laboratory for Deep Processing of Major Grain and Oil of Ministry of Education, Wuhan Polytechnic University, Wuhan 430023, China; (Y.H.); (X.Y.); (J.D.); (Q.Y.)
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19
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Moon JY, Ediriweera MK, Ryu JY, Kim HY, Cho SK. Catechol enhances chemo‑ and radio‑sensitivity by targeting AMPK/Hippo signaling in pancreatic cancer cells. Oncol Rep 2021; 45:1133-1141. [PMID: 33650657 PMCID: PMC7860010 DOI: 10.3892/or.2021.7924] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Accepted: 11/26/2020] [Indexed: 12/11/2022] Open
Abstract
Overcoming chemo‑ and radio‑resistance is a major challenge in pancreatic cancer treatment. Therefore, there is an urgent need to discover novel therapeutic approaches to avoid chemo‑ and radio‑resistance in pancreatic cancer. Catechol is a phytochemical found in some fruits and vegetables. A few studies have reported on the potential anticancer effects of pure catechol. The present study aimed to explore the chemo‑ and radio‑sensitizing effects of catechol in Panc‑1 human pancreatic cancer cells. The effects of catechol on Panc‑1 cell proliferation, clonogenic survival, invasion, and migration were assessed using MTT, cell migration, and Transwell invasion assays. The chemo‑ and radio‑sensitizing effects of catechol on Panc‑1 cells were evaluated via MTT assay and flow cytometry. Western blotting was conducted to analyze the expression of proteins involved in several mechanisms induced by catechol in Panc‑1 cells, including growth inhibition, apoptosis, suppression of epithelial‑mesenchymal transition (EMT), and chemo‑ and radio‑sensitizing activities. The results indicated that catechol inhibited proliferation, promoted apoptosis, and suppressed cell migration, invasion, and EMT in Panc‑1 cells in a dose‑dependent manner. Catechol treatment also induced the phosphorylation of AMP‑activated protein kinase (AMPK) with a concomitant reduction in the expression of Hippo signaling pathway components, including Yes‑associated protein, cysteine‑rich angiogenic inducer 61, and connective tissue growth factor. In addition, catechol enhanced the chemosensitivity of Panc‑1 cells to gemcitabine, a commonly used chemotherapy in pancreatic cancer treatment. A combination of catechol and radiation enhanced apoptosis and increased the expression of two radiation‑induced DNA damage markers, p‑ATM and p‑Chk2. Collectively, the present results demonstrated that catechol, a naturally occurring compound, could suppress the proliferation of pancreatic cancer cells, reduce the expression of EMT‑related proteins, and enhance the chemo‑ and radio‑sensitivity of Panc‑1 cells by targeting AMPK/Hippo signaling.
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Affiliation(s)
- Jeong Yong Moon
- Subtropical/Tropical Organism Gene Bank, Jeju National University, Jeju Special Self‑Governing Province 63243, Republic of Korea
| | - Meran Keshawa Ediriweera
- Subtropical/Tropical Organism Gene Bank, Jeju National University, Jeju Special Self‑Governing Province 63243, Republic of Korea
| | - Ji Yeon Ryu
- School of Biomaterials Science and Technology, College of Applied Life Sciences, Jeju National University, Jeju Special Self‑Governing Province 63243, Republic of Korea
| | - Hee Young Kim
- Interdisciplinary Graduate Program in Advanced Convergence Technology and Science, Jeju National University, Jeju Special Self‑Governing Province 63243, Republic of Korea
| | - Somi Kim Cho
- Subtropical/Tropical Organism Gene Bank, Jeju National University, Jeju Special Self‑Governing Province 63243, Republic of Korea
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20
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Stolarova L, Kleiblova P, Janatova M, Soukupova J, Zemankova P, Macurek L, Kleibl Z. CHEK2 Germline Variants in Cancer Predisposition: Stalemate Rather than Checkmate. Cells 2020; 9:cells9122675. [PMID: 33322746 PMCID: PMC7763663 DOI: 10.3390/cells9122675] [Citation(s) in RCA: 98] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Revised: 12/04/2020] [Accepted: 12/10/2020] [Indexed: 12/15/2022] Open
Abstract
Germline alterations in many genes coding for proteins regulating DNA repair and DNA damage response (DDR) to DNA double-strand breaks (DDSB) have been recognized as pathogenic factors in hereditary cancer predisposition. The ATM-CHEK2-p53 axis has been documented as a backbone for DDR and hypothesized as a barrier against cancer initiation. However, although CHK2 kinase coded by the CHEK2 gene expedites the DDR signal, its function in activation of p53-dependent cell cycle arrest is dispensable. CHEK2 mutations rank among the most frequent germline alterations revealed by germline genetic testing for various hereditary cancer predispositions, but their interpretation is not trivial. From the perspective of interpretation of germline CHEK2 variants, we review the current knowledge related to the structure of the CHEK2 gene, the function of CHK2 kinase, and the clinical significance of CHEK2 germline mutations in patients with hereditary breast, prostate, kidney, thyroid, and colon cancers.
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Affiliation(s)
- Lenka Stolarova
- Institute of Biochemistry and Experimental Oncology, First Faculty of Medicine, Charles University, 12800 Prague, Czech Republic; (L.S.); (M.J.); (J.S.); (P.Z.)
- Laboratory of Cancer Cell Biology, Institute of Molecular Genetics of the Czech Academy of Sciences, 14220 Prague, Czech Republic;
| | - Petra Kleiblova
- Institute of Biology and Medical Genetics, First Faculty of Medicine, Charles University and General University Hospital in Prague, 12800 Prague, Czech Republic;
| | - Marketa Janatova
- Institute of Biochemistry and Experimental Oncology, First Faculty of Medicine, Charles University, 12800 Prague, Czech Republic; (L.S.); (M.J.); (J.S.); (P.Z.)
| | - Jana Soukupova
- Institute of Biochemistry and Experimental Oncology, First Faculty of Medicine, Charles University, 12800 Prague, Czech Republic; (L.S.); (M.J.); (J.S.); (P.Z.)
| | - Petra Zemankova
- Institute of Biochemistry and Experimental Oncology, First Faculty of Medicine, Charles University, 12800 Prague, Czech Republic; (L.S.); (M.J.); (J.S.); (P.Z.)
| | - Libor Macurek
- Laboratory of Cancer Cell Biology, Institute of Molecular Genetics of the Czech Academy of Sciences, 14220 Prague, Czech Republic;
| | - Zdenek Kleibl
- Institute of Biochemistry and Experimental Oncology, First Faculty of Medicine, Charles University, 12800 Prague, Czech Republic; (L.S.); (M.J.); (J.S.); (P.Z.)
- Correspondence: ; Tel.: +420-22496-745
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21
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McIntosh MT, Koganti S, Boatwright JL, Li X, Spadaro SV, Brantly AC, Ayers JB, Perez RD, Burton EM, Burgula S, MacCarthy T, Bhaduri-McIntosh S. STAT3 imparts BRCAness by impairing homologous recombination repair in Epstein-Barr virus-transformed B lymphocytes. PLoS Pathog 2020; 16:e1008849. [PMID: 33002095 PMCID: PMC7529304 DOI: 10.1371/journal.ppat.1008849] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Accepted: 07/31/2020] [Indexed: 12/30/2022] Open
Abstract
Epstein-Barr virus (EBV) causes lymphomas and epithelial cell cancers. Though generally silent in B lymphocytes, this widely prevalent virus can cause endemic Burkitt lymphoma and post-transplant lymphoproliferative disorders/lymphomas in immunocompromised hosts. By learning how EBV breaches barriers to cell proliferation, we hope to undermine those strategies to treat EBV lymphomas and potentially other cancers. We had previously found that EBV, through activation of cellular STAT3 prevents phosphorylation of Chk1, and thereby, suppresses activation of the intra-S phase cell-cycle checkpoint, a potent barrier to oncogene-driven proliferation. This observation prompted us to examine the consequences on DNA repair since homologous recombination repair, the most error-free form, requires phosphoChk1. We now report that the defect in Chk1 phosphorylation also curtails RAD51 nucleation, and thereby, homologous recombination repair of DNA double strand breaks. The resulting reliance on error-prone microhomology-mediated end-joining (MMEJ) repair makes EBV-transformed cells susceptible to PARP inhibition and simultaneous accrual of genome-wide deletions and insertions resulting from synthesis-dependent MMEJ. Analysis of transcriptomic and drug susceptibility data from hundreds of cancer lines reveals a STAT3-dependent gene-set predictive of susceptibility of cancers to synthetic lethal PARP inhibition. These findings i) demonstrate how the tumor virus EBV re-shapes cellular DNA repair, ii) provide the first genome-wide evidence for insertions resulting from MMEJ in human cells, and iii) expand the range of cancers (EBV-related and -unrelated) that are likely to respond to synthetic lethal inhibitors given the high prevalence of cancers with constitutively active STAT3.
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Affiliation(s)
- Michael T. McIntosh
- Child Health Research Institute, Department of Pediatrics, University of Florida, Gainesville, FL, United States of America
- Department of Molecular Genetics and Microbiology, University of Florida, Gainesville, FL, United States of America
- * E-mail: (MTM); (SBM)
| | - Siva Koganti
- Division of Infectious Diseases, Department of Pediatrics, Stony Brook University, Stony Brook, NY, United States of America
| | - J. Lucas Boatwright
- Bioinformatics Core Facility, University of Florida, Gainesville, FL, United States of America
| | - Xiaofan Li
- Division of Infectious Diseases, Department of Pediatrics, University of Florida, Gainesville, FL, United States of America
| | - Salvatore V. Spadaro
- Division of Infectious Diseases, Department of Pediatrics, Stony Brook University, Stony Brook, NY, United States of America
| | - Alexis C. Brantly
- Division of Infectious Diseases, Department of Pediatrics, University of Florida, Gainesville, FL, United States of America
| | - Jasmine B. Ayers
- Division of Infectious Diseases, Department of Pediatrics, Stony Brook University, Stony Brook, NY, United States of America
| | - Ramon D. Perez
- Department of Microbiology and Immunology, Stony Brook University, Stony Brook, NY, United States of America
| | - Eric M. Burton
- Division of Infectious Diseases, Department of Pediatrics, University of Florida, Gainesville, FL, United States of America
| | - Sandeepta Burgula
- Division of Infectious Diseases, Department of Pediatrics, Stony Brook University, Stony Brook, NY, United States of America
| | - Thomas MacCarthy
- Laufer Center for Physical and Quantitative Biology, Stony Brook University, Stony Brook, NY, United States of America
| | - Sumita Bhaduri-McIntosh
- Department of Molecular Genetics and Microbiology, University of Florida, Gainesville, FL, United States of America
- Division of Infectious Diseases, Department of Pediatrics, University of Florida, Gainesville, FL, United States of America
- * E-mail: (MTM); (SBM)
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22
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Valles GJ, Bezsonova I, Woodgate R, Ashton NW. USP7 Is a Master Regulator of Genome Stability. Front Cell Dev Biol 2020; 8:717. [PMID: 32850836 PMCID: PMC7419626 DOI: 10.3389/fcell.2020.00717] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Accepted: 07/13/2020] [Indexed: 12/25/2022] Open
Abstract
Genetic alterations, including DNA mutations and chromosomal abnormalities, are primary drivers of tumor formation and cancer progression. These alterations can endow cells with a selective growth advantage, enabling cancers to evade cell death, proliferation limits, and immune checkpoints, to metastasize throughout the body. Genetic alterations occur due to failures of the genome stability pathways. In many cancers, the rate of alteration is further accelerated by the deregulation of these processes. The deubiquitinating enzyme ubiquitin specific protease 7 (USP7) has recently emerged as a key regulator of ubiquitination in the genome stability pathways. USP7 is also deregulated in many cancer types, where deviances in USP7 protein levels are correlated with cancer progression. In this work, we review the increasingly evident role of USP7 in maintaining genome stability, the links between USP7 deregulation and cancer progression, as well as the rationale of targeting USP7 in cancer therapy.
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Affiliation(s)
- Gabrielle J Valles
- Department of Molecular Biology and Biophysics, UConn Health, Farmington, CT, United States
| | - Irina Bezsonova
- Department of Molecular Biology and Biophysics, UConn Health, Farmington, CT, United States
| | - Roger Woodgate
- Laboratory of Genomic Integrity, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, United States
| | - Nicholas W Ashton
- Laboratory of Genomic Integrity, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, United States
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23
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Chen PH, Tseng WHS, Chi JT. The Intersection of DNA Damage Response and Ferroptosis-A Rationale for Combination Therapeutics. BIOLOGY 2020; 9:E187. [PMID: 32718025 PMCID: PMC7464484 DOI: 10.3390/biology9080187] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 07/16/2020] [Accepted: 07/17/2020] [Indexed: 12/17/2022]
Abstract
Ferroptosis is a novel form of iron-dependent cell death characterized by lipid peroxidation. While the importance and disease relevance of ferroptosis are gaining recognition, much remains unknown about its interaction with other biological processes and pathways. Recently, several studies have identified intricate and complicated interplay between ferroptosis, ionizing radiation (IR), ATM (ataxia-telangiectasia mutated)/ATR (ATM and Rad3-related), and tumor suppressor p53, which signifies the participation of the DNA damage response (DDR) in iron-related cell death. DDR is an evolutionarily conserved response triggered by various DNA insults to attenuate proliferation, enable DNA repairs, and dispose of cells with damaged DNA to maintain genome integrity. Deficiency in proper DDR in many genetic disorders or tumors also highlights the importance of this pathway. In this review, we will focus on the biological crosstalk between DDR and ferroptosis, which is mediated mostly via noncanonical mechanisms. For clinical applications, we also discuss the potential of combining ionizing radiation and ferroptosis-inducers for synergistic effects. At last, various ATM/ATR inhibitors under clinical development may protect ferroptosis and treat many ferroptosis-related diseases to prevent cell death, delay disease progression, and improve clinical outcomes.
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Affiliation(s)
- Po-Han Chen
- Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, NC 27710, USA; (P.-H.C.); (W.H.-S.T.)
- Center for Genomic and Computational Biology, Duke University School of Medicine, Durham, NC 27710, USA
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, CT 06511, USA
| | - Watson Hua-Sheng Tseng
- Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, NC 27710, USA; (P.-H.C.); (W.H.-S.T.)
- Center for Genomic and Computational Biology, Duke University School of Medicine, Durham, NC 27710, USA
- Institute of Clinical Medicine, National Yang-Ming University, Taipei 112, Taiwan
| | - Jen-Tsan Chi
- Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, NC 27710, USA; (P.-H.C.); (W.H.-S.T.)
- Center for Genomic and Computational Biology, Duke University School of Medicine, Durham, NC 27710, USA
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24
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Huang Q, Chen L, Schonbrunn E, Chen J. MDMX inhibits casein kinase 1α activity and stimulates Wnt signaling. EMBO J 2020; 39:e104410. [PMID: 32511789 DOI: 10.15252/embj.2020104410] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Revised: 05/11/2020] [Accepted: 05/13/2020] [Indexed: 12/20/2022] Open
Abstract
Casein kinase 1 alpha (CK1α) is a serine/threonine kinase with numerous functions, including regulating the Wnt/β-catenin and p53 pathways. CK1α has a well-established role in inhibiting the p53 tumor suppressor by binding to MDMX and stimulating MDMX-p53 interaction. MDMX purified from cells contains near-stoichiometric amounts of CK1α, suggesting that MDMX may in turn regulate CK1α function. We present evidence that MDMX is a potent competitive inhibitor of CK1α kinase activity (Ki = 8 nM). Depletion of MDMX increases CK1α activity and β-catenin S45 phosphorylation, whereas ectopic MDMX expression inhibits CK1α activity and β-catenin phosphorylation. The MDMX acidic domain and zinc finger are necessary and sufficient for binding and inhibition of CK1α. P53 binding to MDMX disrupts an intramolecular auto-regulatory interaction and enhances its ability to inhibit CK1α. P53-null mice expressing the MDMXW 200S/W201G mutant, defective in CK1α binding, exhibit reduced Wnt/β-catenin target gene expression and delayed tumor development. Therefore, MDMX is a physiological inhibitor of CK1α and has a role in modulating cellular response to Wnt signaling. The MDMX-CK1α interaction may account for certain p53-independent functions of MDMX.
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Affiliation(s)
- Qingling Huang
- Molecular Oncology Department, Moffitt Cancer Center, Tampa, FL, USA
| | - Lihong Chen
- Molecular Oncology Department, Moffitt Cancer Center, Tampa, FL, USA
| | - Ernst Schonbrunn
- Drug Discovery Department, Moffitt Cancer Center, Tampa, FL, USA
| | - Jiandong Chen
- Molecular Oncology Department, Moffitt Cancer Center, Tampa, FL, USA
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25
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Karakostis K, Vadivel Gnanasundram S, López I, Thermou A, Wang L, Nylander K, Olivares-Illana V, Fåhraeus R. A single synonymous mutation determines the phosphorylation and stability of the nascent protein. J Mol Cell Biol 2020; 11:187-199. [PMID: 30252118 DOI: 10.1093/jmcb/mjy049] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Revised: 05/29/2018] [Accepted: 06/19/2018] [Indexed: 01/06/2023] Open
Abstract
p53 is an intrinsically disordered protein with a large number of post-translational modifications and interacting partners. The hierarchical order and subcellular location of these events are still poorly understood. The activation of p53 during the DNA damage response (DDR) requires a switch in the activity of the E3 ubiquitin ligase MDM2 from a negative to a positive regulator of p53. This is mediated by the ATM kinase that regulates the binding of MDM2 to the p53 mRNA facilitating an increase in p53 synthesis. Here we show that the binding of MDM2 to the p53 mRNA brings ATM to the p53 polysome where it phosphorylates the nascent p53 at serine 15 and prevents MDM2-mediated degradation of p53. A single synonymous mutation in p53 codon 22 (L22L) prevents the phosphorylation of the nascent p53 protein and the stabilization of p53 following genotoxic stress. The ATM trafficking from the nucleus to the p53 polysome is mediated by MDM2, which requires its interaction with the ribosomal proteins RPL5 and RPL11. These results show how the ATM kinase phosphorylates the p53 protein while it is being synthesized and offer a novel mechanism whereby a single synonymous mutation controls the stability and activity of the encoded protein.
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Affiliation(s)
- Konstantinos Karakostis
- Équipe Labellisée Ligue Contre le Cancer, Université Paris 7, INSERM UMR 1162, 27 Rue Juliette Dodu, Paris, France
| | | | - Ignacio López
- Équipe Labellisée Ligue Contre le Cancer, Université Paris 7, INSERM UMR 1162, 27 Rue Juliette Dodu, Paris, France
| | - Aikaterini Thermou
- Équipe Labellisée Ligue Contre le Cancer, Université Paris 7, INSERM UMR 1162, 27 Rue Juliette Dodu, Paris, France
| | - Lixiao Wang
- Department of Medical Biosciences, Umeå University, Umeå, Sweden
| | - Karin Nylander
- Department of Medical Biosciences, Umeå University, Umeå, Sweden
| | | | - Robin Fåhraeus
- Équipe Labellisée Ligue Contre le Cancer, Université Paris 7, INSERM UMR 1162, 27 Rue Juliette Dodu, Paris, France.,Department of Medical Biosciences, Umeå University, Umeå, Sweden.,RECAMO, Masaryk Memorial Cancer Institute, Zluty kopec 7, Brno, Czech Republic
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26
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Magnussen HM, Ahmed SF, Sibbet GJ, Hristova VA, Nomura K, Hock AK, Archibald LJ, Jamieson AG, Fushman D, Vousden KH, Weissman AM, Huang DT. Structural basis for DNA damage-induced phosphoregulation of MDM2 RING domain. Nat Commun 2020; 11:2094. [PMID: 32350255 PMCID: PMC7190642 DOI: 10.1038/s41467-020-15783-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Accepted: 03/27/2020] [Indexed: 01/30/2023] Open
Abstract
Phosphorylation of MDM2 by ATM upon DNA damage is an important mechanism for deregulating MDM2, thereby leading to p53 activation. ATM phosphorylates multiple residues near the RING domain of MDM2, but the underlying molecular basis for deregulation remains elusive. Here we show that Ser429 phosphorylation selectively enhances the ubiquitin ligase activity of MDM2 homodimer but not MDM2-MDMX heterodimer. A crystal structure of phospho-Ser429 (pS429)-MDM2 bound to E2-ubiquitin reveals a unique 310-helical feature present in MDM2 homodimer that allows pS429 to stabilize the closed E2-ubiquitin conformation and thereby enhancing ubiquitin transfer. In cells Ser429 phosphorylation increases MDM2 autoubiquitination and degradation upon DNA damage, whereas S429A substitution protects MDM2 from auto-degradation. Our results demonstrate that Ser429 phosphorylation serves as a switch to boost the activity of MDM2 homodimer and promote its self-destruction to enable rapid p53 stabilization and resolve a long-standing controversy surrounding MDM2 auto-degradation in response to DNA damage.
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Affiliation(s)
- Helge M Magnussen
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow, G61 1BD, UK
- Institute of Cancer Sciences, University of Glasgow, Glasgow, G61 1QH, UK
| | - Syed F Ahmed
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow, G61 1BD, UK
| | - Gary J Sibbet
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow, G61 1BD, UK
| | - Ventzislava A Hristova
- Laboratory of Protein Dynamics and Signaling, Center for Cancer Research, National Cancer Institute, Frederick, MD, 21702, USA
| | - Koji Nomura
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow, G61 1BD, UK
- Institute of Cancer Sciences, University of Glasgow, Glasgow, G61 1QH, UK
| | - Andreas K Hock
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow, G61 1BD, UK
- AstraZeneca, AstraZeneca R&D, Innovative Medicines, Discovery Sciences, Darwin (Building 310), Cambridge Science Park, Milton Road, Cambridge, CB4 0WG, UK
| | - Lewis J Archibald
- School of Chemistry, University of Glasgow, Joseph Black Building, G12 8QQ, Glasgow, UK
| | - Andrew G Jamieson
- School of Chemistry, University of Glasgow, Joseph Black Building, G12 8QQ, Glasgow, UK
| | - David Fushman
- Department of Chemistry and Biochemistry, Center for Biomolecular Structure and Organization, University of Maryland, College Park, MD, 20742, USA
| | | | - Allan M Weissman
- Laboratory of Protein Dynamics and Signaling, Center for Cancer Research, National Cancer Institute, Frederick, MD, 21702, USA
| | - Danny T Huang
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow, G61 1BD, UK.
- Institute of Cancer Sciences, University of Glasgow, Glasgow, G61 1QH, UK.
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27
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Xia Y, Wang L, Ma X, Li X. Investigation on the Genomic Characterization of Uterine Sarcoma for rAd- p53 Combined with Chemotherapy Treatment. Hum Gene Ther 2020; 31:881-890. [PMID: 32013587 DOI: 10.1089/hum.2019.305] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
The aim is to investigate the genomic characterization of uterine sarcoma for rAd-p53 (Gendicine®) combined with chemotherapy treatment. We recently published an article on 12 cases of uterine sarcomas, which were treated with rAd-p53 combined with chemotherapy. We found that rAd-p53 combined with chemotherapy is effective for various uterine sarcomas. Pretreatment pathological specimens of four uterine sarcoma patients were collected from the above recent clinical research and numbered 1-4A/B. Tumor samples were subjected to targeted sequencing by using a 416 genes panel. We profiled the mutation spectrum and tumor mutation burden in the tumors, identified mutated genes, and explored their gene function. We also verified the p53 protein expression using immunohistochemistry. We identified a total of 30 mutated genes that were found from the next-generation sequencing test results. The average number of mutated genes was up to seven in the five samples. TP53 gene was mutated in two of the four patients, No. 1 and No. 4B. They are c.C833G (p.P278R) missense mutation and a point mutation (C141*) that result in a premature stop codon. We did not find a mutated TP53 gene in the other two cases, but we identified mutated genes, including CREBBP, LYN, CDKN2A, and JAK2, which were located upstream of the TP53 gene; they may have an impact on TP53. We also identified 11 additional genes which are involved in p53-related signaling pathways or have interaction with p53. Compared to solid tumor mutational burden (TMB) distribution, none of their TMB was ranking in the top 25%. Mutant p53 protein expression was positive in two specimens. Our results demonstrated that the TP53 signaling pathway plays an important role in uterine sarcoma tumorigenesis. TP53 and the upstream genes such as CREBBP, LYN, CDKN2A, and JAK2 may be involved in the genomic characterization for rAd-p53 (Gendicine) combined with chemotherapy in uterine sarcoma. Besides, the average amount of mutated genes from every patient is large.
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Affiliation(s)
- Yu Xia
- Department of Obstetrics and Gynecology, Shengjing Hospital of China Medical University, Shenyang, China
| | - Lei Wang
- Department of Obstetrics and Gynecology, Shengjing Hospital of China Medical University, Shenyang, China
| | - Xiaolin Ma
- Department of Obstetrics and Gynecology, Shengjing Hospital of China Medical University, Shenyang, China
| | - Xiuqin Li
- Department of Obstetrics and Gynecology, Shengjing Hospital of China Medical University, Shenyang, China
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28
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AlDubayan SH, Pyle LC, Gamulin M, Kulis T, Moore ND, Taylor-Weiner A, Hamid AA, Reardon B, Wubbenhorst B, Godse R, Vaughn DJ, Jacobs LA, Meien S, Grgic M, Kastelan Z, Markt SC, Damrauer SM, Rader DJ, Kember RL, Loud JT, Kanetsky PA, Greene MH, Sweeney CJ, Kubisch C, Nathanson KL, Van Allen EM, Stewart DR, Lessel D. Association of Inherited Pathogenic Variants in Checkpoint Kinase 2 (CHEK2) With Susceptibility to Testicular Germ Cell Tumors. JAMA Oncol 2020; 5:514-522. [PMID: 30676620 DOI: 10.1001/jamaoncol.2018.6477] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Importance Approximately 50% of the risk for the development of testicular germ cell tumors (TGCTs) is estimated to be heritable, but no mendelian TGCT predisposition genes have yet been identified. It is hypothesized that inherited pathogenic DNA repair gene (DRG) alterations may drive susceptibility to TGCTs. Objective To systematically evaluate the enrichment of germline pathogenic variants in the mendelian cancer predisposition DRGs in patients with TGCTs vs healthy controls. Design, Setting, and Participants A case-control enrichment analysis was performed from January 2016 to May 2018 to screen for 48 DRGs in 205 unselected men with TGCT and 27 173 ancestry-matched cancer-free individuals from the Exome Aggregation Consortium cohort in the discovery stage. Significant findings were selectively replicated in independent cohorts of 448 unselected men with TGCTs and 442 population-matched controls, as well as 231 high-risk men with TGCTs and 3090 ancestry-matched controls. Statistical analysis took place from January to May 2018. Main Outcomes and Measures Gene-level enrichment analysis of germline pathogenic variants in individuals with TGCTs relative to cancer-free controls. Results Among 205 unselected men with TGCTs (mean [SD] age, 33.04 [9.67] years), 22 pathogenic germline DRG variants, one-third of which were in CHEK2 (OMIM 604373), were identified in 20 men (9.8%; 95% CI, 6.1%-14.7%). Unselected men with TGCTs were approximately 4 times more likely to carry germline loss-of-function CHEK2 variants compared with cancer-free individuals from the Exome Aggregation Consortium cohort (odds ratio [OR], 3.87; 95% CI, 1.65-8.86; nominal P = .006; q = 0.018). Similar enrichment was also seen in an independent cohort of 448 unselected Croatian men with TGCTs (mean [SD] age, 31.98 [8.11] years) vs 442 unselected Croatian men without TGCTs (at least 50 years of age at time of sample collection) (OR, >1.4; P = .03) and 231 high-risk men with TGCTs (mean [SD] age, 31.54 [9.24] years) vs 3090 men (all older than 50 years) from the Penn Medicine Biobank (OR, 6.30; 95% CI, 2.34-17.31; P = .001). The low-penetrance CHEK2 variant (p.Ile157Thr) was found to be a Croatian founder TGCT risk variant (OR, 3.93; 95% CI, 1.53-9.95; P = .002). Individuals with the pathogenic CHEK2 loss-of-function variants developed TGCTs 6 years earlier than individuals with CHEK2 wild-type alleles (5.95 years; 95% CI, 1.48-10.42; P = .009). Conclusions and Relevance This multicenter case-control analysis of men with or without TGCTs provides evidence for CHEK2 as a novel moderate-penetrance TGCT susceptibility gene, with potential clinical utility. In addition to highlighting DNA-repair deficiency as a potential mechanism driving TGCT susceptibility, this analysis also provides new avenues to explore management strategies and biological investigations for high-risk individuals.
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Affiliation(s)
- Saud H AlDubayan
- Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts.,Cancer Program, the Broad Institute of MIT and Harvard, Cambridge, Massachusetts.,Division of Genetics, Brigham and Women's Hospital, Boston, Massachusetts.,Department of Medicine, King Saud bin Abdul-Aziz University for Health Sciences, Riyadh, Saudi Arabia
| | - Louise C Pyle
- Division of Human Genetics, Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania.,Division of Translational Medicine and Human Genetics, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia
| | - Marija Gamulin
- Division of Medical Oncology, Urogenital Unit, Department of Oncology, University Hospital Centre Zagreb, Zagreb, Croatia
| | - Tomislav Kulis
- Department of Urology, University Hospital Center Zagreb, University of Zagreb, School of Medicine, Zagreb, Croatia
| | - Nathanael D Moore
- Cancer Program, the Broad Institute of MIT and Harvard, Cambridge, Massachusetts
| | - Amaro Taylor-Weiner
- Cancer Program, the Broad Institute of MIT and Harvard, Cambridge, Massachusetts
| | - Anis A Hamid
- Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts.,Cancer Program, the Broad Institute of MIT and Harvard, Cambridge, Massachusetts
| | - Brendan Reardon
- Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts.,Cancer Program, the Broad Institute of MIT and Harvard, Cambridge, Massachusetts
| | - Bradley Wubbenhorst
- Division of Translational Medicine and Human Genetics, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia
| | - Rama Godse
- Division of Translational Medicine and Human Genetics, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia
| | - David J Vaughn
- Division of Hematology/Oncology, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia
| | - Linda A Jacobs
- Abramson Cancer Center, Perelman School of Medicine, University of Pennsylvania, Philadelphia
| | - Stefanie Meien
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Mislav Grgic
- Division of Medical Oncology, Urogenital Unit, Department of Oncology, University Hospital Centre Zagreb, Zagreb, Croatia
| | - Zeljko Kastelan
- Department of Urology, University Hospital Center Zagreb, University of Zagreb, School of Medicine, Zagreb, Croatia
| | - Sarah C Markt
- Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, Massachusetts
| | - Scott M Damrauer
- Department of Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia
| | - Daniel J Rader
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia
| | - Rachel L Kember
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia
| | - Jennifer T Loud
- Clinical Genetics Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, Maryland
| | - Peter A Kanetsky
- Department of Cancer Epidemiology, Moffitt Cancer Center and Research Institute, Tampa, Florida
| | - Mark H Greene
- Clinical Genetics Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, Maryland
| | - Christopher J Sweeney
- Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts
| | - Christian Kubisch
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Katherine L Nathanson
- Division of Translational Medicine and Human Genetics, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia.,Abramson Cancer Center, Perelman School of Medicine, University of Pennsylvania, Philadelphia
| | - Eliezer M Van Allen
- Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts.,Cancer Program, the Broad Institute of MIT and Harvard, Cambridge, Massachusetts
| | - Douglas R Stewart
- Clinical Genetics Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, Maryland
| | - Davor Lessel
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
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Chen S, Zhou Q, Guo Z, Wang Y, Wang L, Liu X, Lu M, Ju L, Xiao Y, Wang X. Inhibition of MELK produces potential anti-tumour effects in bladder cancer by inducing G1/S cell cycle arrest via the ATM/CHK2/p53 pathway. J Cell Mol Med 2019; 24:1804-1821. [PMID: 31821699 PMCID: PMC6991658 DOI: 10.1111/jcmm.14878] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Revised: 10/30/2019] [Accepted: 11/16/2019] [Indexed: 12/13/2022] Open
Abstract
We aimed to investigate the biological function of MELK and the therapeutic potential of OTSSP167 in human bladder cancer (BCa). First, we observed overexpression of MELK in BCa cell lines and tissues and found that it was associated with higher tumour stage and tumour grade, which was consistent with transcriptome analysis. High expression of MELK was significantly correlated with poor prognosis in BCa patients, and MELK was found to have a role in the cell cycle, the G1/S transition in mitosis, and DNA repair and replication. Furthermore, BCa cells presented significantly decreased proliferation capacity following silencing of MELK or treatment with OTSSP167 in vitro and in vivo. Functionally, reduction in MELK or treatment of cells with OTSSP167 could induce cell cycle arrest and could suppress migration. In addition, these treatments could activate phosphorylation of ATM and CHK2, which would be accompanied by down‐regulated MDMX, cyclin D1, CDK2 and E2F1; however, p53 and p21 would be activated. Opposite results were observed when MELK expression was induced. Overall, MELK was found to be a novel oncogene in BCa that induces cell cycle arrest via the ATM/CHK2/p53 pathway. OTSSP167 displays potent anti‐tumour activities, which may provide a new molecule‐based strategy for BCa treatment.
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Affiliation(s)
- Song Chen
- Department of Urology, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Qiang Zhou
- Department of Urology, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Zicheng Guo
- Department of Urology, Zhongnan Hospital of Wuhan University, Wuhan, China.,Department of Urology, Enshi Clinical College of Wuhan University, Enshi, China
| | - Yejinpeng Wang
- Department of Urology, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Lu Wang
- Department of Urology, Zhongnan Hospital of Wuhan University, Wuhan, China.,Department of Urology, Qingdao Municipal Hospital, Qingdao University, Qingdao, China
| | - Xuefeng Liu
- Department of Pathology, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, DC, USA
| | - Mengxin Lu
- Department of Urology, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Lingao Ju
- Department of Biological Repositories, Zhongnan Hospital of Wuhan University, Wuhan, China.,Laboratory of Precision Medicine, Zhongnan Hospital of Wuhan University, Wuhan, China.,Human Genetics Resource Preservation Center of Hubei Province, Wuhan, China
| | - Yu Xiao
- Department of Urology, Zhongnan Hospital of Wuhan University, Wuhan, China.,Department of Biological Repositories, Zhongnan Hospital of Wuhan University, Wuhan, China.,Laboratory of Precision Medicine, Zhongnan Hospital of Wuhan University, Wuhan, China.,Human Genetics Resource Preservation Center of Hubei Province, Wuhan, China
| | - Xinghuan Wang
- Department of Urology, Zhongnan Hospital of Wuhan University, Wuhan, China.,Human Genetics Resource Preservation Center of Hubei Province, Wuhan, China.,Medical Research Institute, Wuhan University, Wuhan, China
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30
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Kwon HJ, Kim LH, Ahn CH, Yang IH, Hong KO, Doo Hong S, Shin JA, Cho SD. A new insight into the apoptotic effect of nitidine chloride targeting Checkpoint kinase 2 in human cervical cancer in vitro. J Clin Biochem Nutr 2019; 65:193-202. [PMID: 31777420 PMCID: PMC6877403 DOI: 10.3164/jcbn.19-28] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Accepted: 08/14/2019] [Indexed: 12/12/2022] Open
Abstract
Nitidine chloride (NC), a natural, bioactive, phytochemical alkaloid derived from the roots of Zanthoxylum nitidum, has been reported to exhibit anti-tumor activity against various types of cancer. However, the potential therapeutic role of NC in human cervical cancer has not yet been studied. We are the first to report that NC acts as a potential apoptosis-inducing agent for human cervical cancer in vitro. NC treatment of human cervical cancer cell lines induced caspase-mediated apoptosis, thereby reducing cell viability. Phospho-kinase proteome profiling using a human phospho-kinase array revealed that NC treatment phosphorylated Checkpoint kinase 2 (Chk2) at Thr68, which activates Chk2 in both cell lines. We also found that NC significantly affected the p53/Bim signaling axis, which was accompanied by mitochondrial membrane depolarization and cytochrome c release from the mitochondria into the cytosol. In addition, NC profoundly increased phosphorylation of the histone variant H2AX at Ser139, a typical marker of DNA damage. Taken together, these results provide in vitro evidence that NC can increase Chk2 activation, thereby acting as an attractive cell death inducer for treatment of human cervical cancer.
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Affiliation(s)
- Hye-Jeong Kwon
- Department of Oral Pathology, School of Dentistry and Dental Research Institute, Seoul National University, 101 Daehak-ro, Jongno-gu, Seoul 03080, Republic of Korea
| | - Lee-Han Kim
- Department of Microbiology, Institute for Immunology and Immunological Diseases, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul 03722, Republic of Korea
| | - Chi-Hyun Ahn
- Department of Oral Pathology, School of Dentistry and Dental Research Institute, Seoul National University, 101 Daehak-ro, Jongno-gu, Seoul 03080, Republic of Korea
| | - In-Hyoung Yang
- Department of Oral Pathology, School of Dentistry and Dental Research Institute, Seoul National University, 101 Daehak-ro, Jongno-gu, Seoul 03080, Republic of Korea
| | - Kyoung-Ok Hong
- Department of Oral Pathology, School of Dentistry and Dental Research Institute, Seoul National University, 101 Daehak-ro, Jongno-gu, Seoul 03080, Republic of Korea
| | - Seong Doo Hong
- Department of Oral Pathology, School of Dentistry and Dental Research Institute, Seoul National University, 101 Daehak-ro, Jongno-gu, Seoul 03080, Republic of Korea
| | - Ji-Ae Shin
- Department of Oral Pathology, School of Dentistry and Dental Research Institute, Seoul National University, 101 Daehak-ro, Jongno-gu, Seoul 03080, Republic of Korea
| | - Sung-Dae Cho
- Department of Oral Pathology, School of Dentistry and Dental Research Institute, Seoul National University, 101 Daehak-ro, Jongno-gu, Seoul 03080, Republic of Korea
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31
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Liang M, Li H, Wang Z, Cai L, Yang L. Rice protein reduces DNA damage by activating the p53 pathway and stimulating endogenous antioxidant response in growing and adult rats. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2019; 99:6097-6107. [PMID: 31250448 DOI: 10.1002/jsfa.9888] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 06/20/2019] [Accepted: 06/21/2019] [Indexed: 06/09/2023]
Abstract
BACKGROUND Reactive oxygen species (ROS) can cause DNA damage. Rice protein (RP) inhibits ROS accumulation. However, a link between the reduction of ROS-derived DNA damage and the intake of RP is far from clear. The main objective of this study is to elucidate the effects of RPs on the reduction of DNA damage in growing and adult rats. RESULTS An intake of RP for 2 weeks significantly reduced the hepatic accumulation of ROS and 8-hydroxydeoxyguanosine (8-OHdG) in growing and adult rats, whereas the hepatic p53 content was markedly increased by RPs. After 2 weeks' feeding, the mRNA levels and protein expressions of p53, ataxia-telangiectasia mutated (ATM), and Checkpoint kinase 2 (Chk2) were up-regulated by RPs, whereas Murine Double Minute 2 (MDM2) expressions were markedly inhibited by RPs, resulting in more p53 being translocated into the nucleus. Nuclear factor erythroid 2 (NF-E2)-related factor 2 (Nrf2) was activated by RP by reducing Kelch-like ECH-associated protein 1 (Keap1), resulting in the up-regulation of antioxidant expressions of catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) in RP groups. CONCLUSION Rice protein can exert an endogenous antioxidant activity to reduce ROS-derived DNA damage by activating the Nrf2-Keap1 pathway. This study suggests that the activation of the ATM-Chk2-p53 pathway might be one of the mechanisms exerted by RP for reducing DNA damage in growing and adult rats. © 2019 Society of Chemical Industry.
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Affiliation(s)
- Mingcai Liang
- Department of Food Science and Engineering, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin, China
| | - Hui Li
- Department of Food Science and Engineering, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin, China
| | - Zhengxuan Wang
- Department of Food Science and Engineering, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin, China
| | - Liang Cai
- Department of Food Science and Engineering, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin, China
| | - Lin Yang
- Department of Food Science and Engineering, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin, China
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32
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Haupt S, Mejía-Hernández JO, Vijayakumaran R, Keam SP, Haupt Y. The long and the short of it: the MDM4 tail so far. J Mol Cell Biol 2019; 11:231-244. [PMID: 30689920 PMCID: PMC6478121 DOI: 10.1093/jmcb/mjz007] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Revised: 12/16/2018] [Accepted: 01/21/2019] [Indexed: 12/27/2022] Open
Abstract
The mouse double minute 4 (MDM4) is emerging from the shadow of its more famous relative MDM2 and is starting to steal the limelight, largely due to its therapeutic possibilities. MDM4 is a vital regulator of the tumor suppressor p53. It restricts p53 transcriptional activity and also, at least in development, facilitates MDM2's E3 ligase activity toward p53. These functions of MDM4 are critical for normal cell function and a proper response to stress. Their importance for proper cell maintenance and proliferation identifies them as a risk for deregulation associated with the uncontrolled growth of cancer. MDM4 tails are vital for its function, where its N-terminus transactivation domain engages p53 and its C-terminus RING domain binds to MDM2. In this review, we highlight recently identified cellular functions of MDM4 and survey emerging therapies directed to correcting its dysregulation in disease.
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Affiliation(s)
- Sue Haupt
- Tumor Suppression Laboratory, Peter MacCallum Cancer Centre, 305 Grattan Street, Melbourne, Victoria, Australia
- Department of Clinical Pathology, The University of Melbourne, Parkville, Victoria, Australia
| | | | - Reshma Vijayakumaran
- Tumor Suppression Laboratory, Peter MacCallum Cancer Centre, 305 Grattan Street, Melbourne, Victoria, Australia
| | - Simon P Keam
- Tumor Suppression Laboratory, Peter MacCallum Cancer Centre, 305 Grattan Street, Melbourne, Victoria, Australia
| | - Ygal Haupt
- Tumor Suppression Laboratory, Peter MacCallum Cancer Centre, 305 Grattan Street, Melbourne, Victoria, Australia
- Department of Clinical Pathology, The University of Melbourne, Parkville, Victoria, Australia
- Department of Biochemistry and Molecular Biology, Monash University, Clayton Campus, Victoria, Australia
- Sir Peter MacCallum Department of Oncology, The University of Melbourne, Parkville, Victoria, Australia
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33
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Moussa RS, Park KC, Kovacevic Z, Richardson DR. Ironing out the role of the cyclin-dependent kinase inhibitor, p21 in cancer: Novel iron chelating agents to target p21 expression and activity. Free Radic Biol Med 2019; 133:276-294. [PMID: 29572098 DOI: 10.1016/j.freeradbiomed.2018.03.027] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Revised: 03/02/2018] [Accepted: 03/14/2018] [Indexed: 12/12/2022]
Abstract
Iron (Fe) has become an important target for the development of anti-cancer therapeutics with a number of Fe chelators entering human clinical trials for advanced and resistant cancer. An important aspect of the activity of these compounds is their multiple molecular targets, including those that play roles in arresting the cell cycle, such as the cyclin-dependent kinase inhibitor, p21. At present, the exact mechanism by which Fe chelators regulate p21 expression remains unclear. However, recent studies indicate the ability of chelators to up-regulate p21 at the mRNA level was dependent on the chelator and cell-type investigated. Analysis of the p21 promoter identified that the Sp1-3-binding site played a significant role in the activation of p21 transcription by Fe chelators. Furthermore, there was increased Sp1/ER-α and Sp1/c-Jun complex formation in melanoma cells, suggesting these complexes were involved in p21 promoter activation. Elucidating the mechanisms involved in the regulation of p21 expression in response to Fe chelator treatment in neoplastic cells will further clarify how these agents achieve their anti-tumor activity. It will also enhance our understanding of the complex roles p21 may play in neoplastic cells and lead to the development of more effective and specific anti-cancer therapies.
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Affiliation(s)
- Rayan S Moussa
- Molecular Pharmacology and Pathology Program, Discipline of Pathology and Bosch Institute, Medical Foundation Building (K25), The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Kyung Chan Park
- Molecular Pharmacology and Pathology Program, Discipline of Pathology and Bosch Institute, Medical Foundation Building (K25), The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Zaklina Kovacevic
- Molecular Pharmacology and Pathology Program, Discipline of Pathology and Bosch Institute, Medical Foundation Building (K25), The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Des R Richardson
- Molecular Pharmacology and Pathology Program, Discipline of Pathology and Bosch Institute, Medical Foundation Building (K25), The University of Sydney, Sydney, New South Wales 2006, Australia; Department of Pathology and Biological Responses, Nagoya University Graduate School of Medicine, 65 Tsurumai, Showa-ku, Nagoya 466-8550, Japan.
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34
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Xu Q, Li M, Yang M, Yang J, Xie J, Lu X, Wang F, Chen W. α-pinene regulates miR-221 and induces G 2/M phase cell cycle arrest in human hepatocellular carcinoma cells. Biosci Rep 2018; 38:BSR20180980. [PMID: 30473536 PMCID: PMC6294613 DOI: 10.1042/bsr20180980] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Revised: 11/15/2018] [Accepted: 11/20/2018] [Indexed: 01/25/2023] Open
Abstract
The naturally occurring compound α-pinene induces cell cycle arrest and antitumor activity. We examined effects of α-pinene on cell cycle regulation in hepatocellular carcinoma cells (HepG2) cells to establish a foundation for its development as a novel treatment for hepatocellular carcinoma (HCC). HepG2 cells treated with α-pinene exhibited dose-dependent growth inhibition as a result of G2/M-phase cell cycle arrest. Cell cycle arrest was associated with down-regulated cyclin-dependent kinase 1 (CDK1) and miR-221 levels and up-regulated levels of CDKN1B/p27, γ-H2AX, phosphorylated ATM, phosphorylated Chk2 and phosphorylated p53. Our observations are consistent with a model in which α-pinene inhibits miR221 expression, which leads to G2/M-phase arrest and activation of CDKN1B/p27-CDK1 and ATM-p53-Chk2 pathways that suppress human hepatoma tumor progression. Additionally, α-pinene was found to trigger oxidative stress and induce apoptosis of HepG2 cells. α-pinene, therefore, represents a potential chemotherapeutic compound for the treatment of HCC.
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Affiliation(s)
- Qiuxiang Xu
- School of Basic Medicine, Guangdong Pharmaceutical University, Guangzhou Higher Education Mega Center, Outer Ring East Road No. 280, Panyu District, Guangzhou 510006, Guangdong Province, China
| | - Ming Li
- School of Basic Medicine, Guangdong Pharmaceutical University, Guangzhou Higher Education Mega Center, Outer Ring East Road No. 280, Panyu District, Guangzhou 510006, Guangdong Province, China
| | - Mengdie Yang
- School of Basic Medicine, Guangdong Pharmaceutical University, Guangzhou Higher Education Mega Center, Outer Ring East Road No. 280, Panyu District, Guangzhou 510006, Guangdong Province, China
| | - Jiebo Yang
- School of Basic Medicine, Guangdong Pharmaceutical University, Guangzhou Higher Education Mega Center, Outer Ring East Road No. 280, Panyu District, Guangzhou 510006, Guangdong Province, China
| | - Jingjing Xie
- School of Basic Medicine, Guangdong Pharmaceutical University, Guangzhou Higher Education Mega Center, Outer Ring East Road No. 280, Panyu District, Guangzhou 510006, Guangdong Province, China
| | - Xinshuo Lu
- School of Basic Medicine, Guangdong Pharmaceutical University, Guangzhou Higher Education Mega Center, Outer Ring East Road No. 280, Panyu District, Guangzhou 510006, Guangdong Province, China
| | - Fang Wang
- School of Basic Medicine, Guangdong Pharmaceutical University, Guangzhou Higher Education Mega Center, Outer Ring East Road No. 280, Panyu District, Guangzhou 510006, Guangdong Province, China
| | - Weiqiang Chen
- School of Basic Medicine, Guangdong Pharmaceutical University, Guangzhou Higher Education Mega Center, Outer Ring East Road No. 280, Panyu District, Guangzhou 510006, Guangdong Province, China
- Guangdong Province Precise Medicine and Big Data Engineering Technology Research Center for Traditional Chinese medicine, Guangdong Pharmaceutical University, Guangzhou Higher Education Mega Center, Outer Ring East Road No. 280, Panyu District, Guangzhou 510006, Guangdong Province, China
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Neuroblastoma Cell Lines Are Refractory to Genotoxic Drug-Mediated Induction of Ligands for NK Cell-Activating Receptors. J Immunol Res 2018; 2018:4972410. [PMID: 29805983 PMCID: PMC5901817 DOI: 10.1155/2018/4972410] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Revised: 02/07/2018] [Accepted: 02/18/2018] [Indexed: 12/20/2022] Open
Abstract
Neuroblastoma (NB), the most common extracranial solid tumor of childhood, causes death in almost 15% of children affected by cancer. Treatment of neuroblastoma is based on the combination of chemotherapy with other therapeutic interventions such as surgery, radiotherapy, use of differentiating agents, and immunotherapy. In particular, adoptive NK cell transfer is a new immune-therapeutic approach whose efficacy may be boosted by several anticancer agents able to induce the expression of ligands for NK cell-activating receptors, thus rendering cancer cells more susceptible to NK cell-mediated lysis. Here, we show that chemotherapeutic drugs commonly used for the treatment of NB such as cisplatin, topotecan, irinotecan, and etoposide are unable to induce the expression of activating ligands in a panel of NB cell lines. Consistently, cisplatin-treated NB cell lines were not more susceptible to NK cells than untreated cells. The refractoriness of NB cell lines to these drugs has been partially associated with the abnormal status of genes for ATM, ATR, Chk1, and Chk2, the major transducers of the DNA damage response (DDR), triggered by several anticancer agents and promoting different antitumor mechanisms including the expression of ligands for NK cell-activating receptors. Moreover, both the impaired production of reactive oxygen species (ROS) in some NB cell lines and the transient p53 stabilization in response to our genotoxic drugs under our experimental conditions could contribute to inefficient induction of activating ligands. These data suggest that further investigations, exploiting molecular strategies aimed to potentiate the NK cell-mediated immunotherapy of NB, are warranted.
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36
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MDMX acidic domain inhibits p53 DNA binding in vivo and regulates tumorigenesis. Proc Natl Acad Sci U S A 2018; 115:E3368-E3377. [PMID: 29581299 DOI: 10.1073/pnas.1719090115] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The MDM2 homolog MDMX oncoprotein is indispensable for inhibition of p53 during normal embryonic development and malignant transformation, yet how MDMX harnesses p53 functions is unclear. In addition to a canonical N-terminal p53-binding domain, recent work suggests the central acidic domain of MDMX regulates p53 interaction through intramolecular mimicry and engages in second-site interaction with the p53 core domain in vitro. To test the physiological relevance of these interactions, we generated an MDMX knockin mouse having substitutions in a conserved WW motif necessary for these functions (W201S/W202G). Notably, MDMXSG cells have normal p53 level but increased p53 DNA binding and target gene expression, and rapidly senesce. In vivo, MDMXSG inhibits early-phase disease in Eµ-Myc transgenic mice but accelerates the onset of lethal lymphoma and shortens overall survival. Therefore, MDMX is an important regulator of p53 DNA binding, which complements the role of MDM2 in regulating p53 level. Furthermore, the results suggest that the WW motif has dual functions that regulate p53 and inhibit Myc-driven lymphomas independent of p53.
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37
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Galal SA, Khattab M, Shouman SA, Ramadan R, Kandil OM, Kandil OM, Tabll A, El Abd YS, El-Shenawy R, Attia YM, El-Rashedy AA, El Diwani HI. Part III: Novel checkpoint kinase 2 (Chk2) inhibitors; design, synthesis and biological evaluation of pyrimidine-benzimidazole conjugates. Eur J Med Chem 2018; 146:687-708. [PMID: 29407991 DOI: 10.1016/j.ejmech.2018.01.072] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Revised: 01/20/2018] [Accepted: 01/22/2018] [Indexed: 02/07/2023]
Abstract
Recently a dramatic development of the cancer drug discovery has been shown in the field of targeted cancer therapy. Checkpoint kinase 2 (Chk2) inhibitors offer a promising approach to enhance the effectiveness of cancer chemotherapy. Accordingly, in this study many pyrimidine-benzimidazole conjugates were designed and twelve feasible derivatives were selected to be synthesized to investigate their activity against Chk2 and subjected to study their antitumor activity alone and in combination with the genotoxic anticancer drugs cisplatin and doxorubicin on breast carcinoma, (ER+) cell line (MCF-7). The results indicated that the studied compounds inhibited Chk2 activity with high potency (IC50 = 5.56 nM - 46.20 nM). The studied candidates exhibited remarkable antitumor activity against MCF-7 (IG50 = 6.6 μM - 24.9 μM). Compounds 10a-c, 14 and 15 significantly potentiated the activity of the studied genotoxic drugs, whereas, compounds 9b and 20-23 antagonized their activity. Moreover, the combination of compound 10b with cisplatin revealed the best apoptotic effect as well as combination of compound 10b with doxorubicin led to complete arrest of the cell cycle at S phase where more than 40% of cells are in the S phase with no cells at G2/M. Structure-activity relationship was discussed on the basis of molecular modeling study using Molecular modeling Environment program (MOE).
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Affiliation(s)
- Shadia A Galal
- Department of Chemistry of Natural and Microbial Products, Division of Pharmaceutical and Drug Industries, National Research Centre, Cairo, 12622, Egypt.
| | - Muhammad Khattab
- Department of Chemistry of Natural and Microbial Products, Division of Pharmaceutical and Drug Industries, National Research Centre, Cairo, 12622, Egypt
| | - Samia A Shouman
- Department of Cancer Biology, National Cancer Institute, Cairo University, Egypt
| | - Raghda Ramadan
- Radiobiology Unit, Belgian Nuclear Research Center (SCK•CEN), Mol, Belgium; Department of Basic Medical Sciences, Physiology Group, Ghent University, Ghent, Belgium
| | - Omaima M Kandil
- Department of Animal Reproduction & Artificial Insemination, Division, of Veterinary Research, National Research Centre, Cairo, 12622, Egypt
| | - Omnia M Kandil
- Department of Parasitology, Animal Disease, Division, of Veterinary, National Research Centre, Cairo, 12622, Egypt
| | - Ashraf Tabll
- Department of Microbial Biotechnology, Division of Genetic Engineering & Biotechnology, National Research Centre, 12622, Cairo, Egypt
| | - Yasmine S El Abd
- Department of Microbial Biotechnology, Division of Genetic Engineering & Biotechnology, National Research Centre, 12622, Cairo, Egypt
| | - Reem El-Shenawy
- Department of Microbial Biotechnology, Division of Genetic Engineering & Biotechnology, National Research Centre, 12622, Cairo, Egypt
| | - Yasmin M Attia
- Department of Cancer Biology, National Cancer Institute, Cairo University, Egypt
| | - Ahmed A El-Rashedy
- Department of Chemistry of Natural and Microbial Products, Division of Pharmaceutical and Drug Industries, National Research Centre, Cairo, 12622, Egypt
| | - Hoda I El Diwani
- Department of Chemistry of Natural and Microbial Products, Division of Pharmaceutical and Drug Industries, National Research Centre, Cairo, 12622, Egypt
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Ruihua H, Mengyi Z, Chong Z, Meng Q, Xin M, Qiulin T, Feng B, Ming L. RhoA regulates resistance to irinotecan by regulating membrane transporter and apoptosis signaling in colorectal cancer. Oncotarget 2018; 7:87136-87146. [PMID: 27888624 PMCID: PMC5349977 DOI: 10.18632/oncotarget.13548] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Accepted: 11/08/2016] [Indexed: 02/05/2023] Open
Abstract
Colorectal cancer (CRC) is a major cause of mortality and morbidity worldwide. While surgery remains the mainstay of treatment in early stage CRC, chemotherapy is usually given to prolong the overall survival and improve the quality of life for metastatic colorectal cancer (mCRC). But drug resistance is one of the major hurdles of mCRC treatment, and the underlying mechanisms are still largely unknown. In this study, we show that, compared with parental cells, RhoA is up-regulated in irinotecan (CPT-11)-resistant CRC cells. Furthermore, inhibition of RhoA in drug resistant cells, at least partially, rescues the resistance against irinotecan and increases the sensitivity to other chemotherapeutic drug by inhibiting expression of MDR1, MRP1and GSTP1, promotes apoptosis by suppressing the expression of BCL-XL and Bcl-2 and increasing Bax expression, and significantly decreases side population cells. Our results suggest that, in addition to survival, proliferation, migration, adhesion, cell cycle and gene transcription, RhoA is also involved in chemoresistance by regulating the expression of membrane transporter and apoptosis protein in colorectal cancer. They raise an interesting possibility that the expression of RhoA may indicate a poor prognosis due to the high probability to therapy resistance and, on the other hand, inhibition of RhoA activity and function may overcome chemoresistance and improve the effectiveness of clinical treatment of CRC.
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Affiliation(s)
- Huang Ruihua
- Department of Medical Oncology/Laboratory of Signal Transduction and Molecular Targeted Therapy, West China Hospital, Sichuan University, Chengdu, Sichuan Province, China
| | - Zhang Mengyi
- Department of Medical Oncology/Laboratory of Signal Transduction and Molecular Targeted Therapy, West China Hospital, Sichuan University, Chengdu, Sichuan Province, China
| | - Zhao Chong
- Department of Radiotherapy, The Tumor Hospital of Chengdu/The Seventh Peoples's Hospital of Chengdu, Chengdu, Sichuan Province, China
| | - Qiu Meng
- Department of Medical Oncology/Laboratory of Signal Transduction and Molecular Targeted Therapy, West China Hospital, Sichuan University, Chengdu, Sichuan Province, China
| | - Ma Xin
- Department of Medical Oncology/Laboratory of Signal Transduction and Molecular Targeted Therapy, West China Hospital, Sichuan University, Chengdu, Sichuan Province, China
| | - Tang Qiulin
- Department of Medical Oncology/Laboratory of Signal Transduction and Molecular Targeted Therapy, West China Hospital, Sichuan University, Chengdu, Sichuan Province, China
| | - Bi Feng
- Department of Medical Oncology/Laboratory of Signal Transduction and Molecular Targeted Therapy, West China Hospital, Sichuan University, Chengdu, Sichuan Province, China
| | - Liu Ming
- Department of Medical Oncology/Laboratory of Signal Transduction and Molecular Targeted Therapy, West China Hospital, Sichuan University, Chengdu, Sichuan Province, China
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Cifaldi L, Locatelli F, Marasco E, Moretta L, Pistoia V. Boosting Natural Killer Cell-Based Immunotherapy with Anticancer Drugs: a Perspective. Trends Mol Med 2017; 23:1156-1175. [PMID: 29133133 DOI: 10.1016/j.molmed.2017.10.002] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Revised: 10/12/2017] [Accepted: 10/16/2017] [Indexed: 12/27/2022]
Abstract
Natural killer (NK) cells efficiently recognize and kill tumor cells through several mechanisms including the expression of ligands for NK cell-activating receptors on target cells. Different clinical trials indicate that NK cell-based immunotherapy represents a promising antitumor treatment. However, tumors develop immune-evasion strategies, including downregulation of ligands for NK cell-activating receptors, that can negatively affect antitumor activity of NK cells, which either reside endogenously, or are adoptively transferred. Thus, restoration of the expression of NK cell-activating ligands on tumor cells represents a strategic therapeutic goal. As discussed here, various anticancer drugs can fulfill this task via different mechanisms. We envision that the combination of selected chemotherapeutic agents with NK cell adoptive transfer may represent a novel strategy for cancer immunotherapy.
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Affiliation(s)
- Loredana Cifaldi
- Department of Pediatric Haematology/Oncology, Ospedale Pediatrico Bambino Gesù, IRCCS, Rome, Italy.
| | - Franco Locatelli
- Department of Pediatric Haematology/Oncology, Ospedale Pediatrico Bambino Gesù, IRCCS, Rome, Italy; Department of Pediatric Sciences, University of Pavia, Pavia, Italy
| | - Emiliano Marasco
- Department of Rheumatology, Ospedale Pediatrico Bambino Gesù, IRCCS, Rome, Italy
| | - Lorenzo Moretta
- Immunology Research Area, Ospedale Pediatrico Bambino Gesù, IRCCS, Rome, Italy
| | - Vito Pistoia
- Immunology Research Area, Ospedale Pediatrico Bambino Gesù, IRCCS, Rome, Italy
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40
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Lee JY, Kim MS, Ju JE, Lee MS, Chung N, Jeong YK. Simvastatin enhances the radiosensitivity of p53‑deficient cells via inhibition of mouse double minute 2 homolog. Int J Oncol 2017; 52:211-218. [PMID: 29115437 DOI: 10.3892/ijo.2017.4192] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Accepted: 10/21/2017] [Indexed: 11/05/2022] Open
Abstract
Simvastatin exhibits anticancer activities, but its molecular mechanisms and radiosensitizing effects relative to p53 status remain unclear. In this study, we investigated whether the combination of simvastatin and ionizing radiation (IR) would enhance the antitumor effects of IR alone in HCT116 p53+/+ and p53‑/- colon cancer cells. Using colony formation assays and a xenograft mouse model, we found that simvastatin potently stimulated radiosensitization of HCT116 p53‑/- cells and xenograft tumors. The combination of simvastatin with IR decreased G2/M arrest and delayed the repair of IR-induced DNA damage; however, no differences between the HCT116 p53+/+ and p53‑/- cells were evident. A further analysis revealed that simvastatin exhibited a novel function, namely, MDM2 suppression, regardless of p53 status. Interestingly, simvastatin induced radiosensitization by enhancing MDM2 suppression and elevating IR-induced p‑ATM foci formation compared with IR alone in HCT116 p53‑/- cells. Furthermore, simvastatin caused accumulations of the FOXO3a, E-cadherin, and p21 tumor suppressor proteins, which are downstream factors of MDM2, in HCT116 p53‑/- cells. In conclusion, simvastatin enhanced radiosensitivity by inducing MDM2 inhibition and increasing tumor suppressor protein levels in radioresistant HCT116 p53‑/- cells and xenografts. Overall, our novel findings suggest a scientific rationale for the clinical use of simvastatin as an MDM2 inhibitor and radiosensitizer for p53‑deficient colorectal tumor treatments.
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Affiliation(s)
- Ji Young Lee
- Radiation Non-Clinical Center, Korea Institute of Radiological and Medical Sciences, Seoul, Republic of Korea
| | - Mi-Sook Kim
- Department of Radiation Oncology, Korea Institute of Radiological and Medical Sciences, Seoul, Republic of Korea
| | - Jae Eun Ju
- Radiation Non-Clinical Center, Korea Institute of Radiological and Medical Sciences, Seoul, Republic of Korea
| | - Mi So Lee
- Radiation Non-Clinical Center, Korea Institute of Radiological and Medical Sciences, Seoul, Republic of Korea
| | - Namhyun Chung
- Department of Biosystems Engineering, College of Life Sciences and Biotechnology, Korea University, Seoul, Republic of Korea
| | - Youn Kyoung Jeong
- Radiation Non-Clinical Center, Korea Institute of Radiological and Medical Sciences, Seoul, Republic of Korea
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41
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Hauck PM, Wolf ER, Olivos DJ, McAtarsney CP, Mayo LD. The fate of murine double minute X (MdmX) is dictated by distinct signaling pathways through murine double minute 2 (Mdm2). Oncotarget 2017; 8:104455-104466. [PMID: 29262653 PMCID: PMC5732819 DOI: 10.18632/oncotarget.22320] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Accepted: 10/05/2017] [Indexed: 01/17/2023] Open
Abstract
Mouse double minute 2 (Mdm2) and MdmX dimerize in response to low levels of genotoxic stress to function in a ubiquitinating complex, which signals for destabilization of p53. Under growth conditions, Mdm2 functions as a neddylating ligase, but the importance and extent of MdmX involvement in this process are largely unknown. Here we show that when Mdm2 functions as a neddylating enzyme, MdmX is stabilized. Furthermore, we demonstrate that under growth conditions, MdmX enhances the neddylation activity of Mdm2 on p53 and is a substrate for neddylation itself. Importantly, MdmX knockdown in MCF-7 breast cancer cells resulted in diminished neddylated p53, suggesting that MdmX is important for Mdm2-mediated neddylation. Supporting this finding, the lack of MdmX in transient assays or in p53/MdmX-/- MEFs results in decreased or altered neddylation of p53 respectively; therefore, MdmX is a critical component of the Mdm2-mediated neddylating complex. c-Src is the upstream activator of this Mdm2-MdmX neddylating pathway and loss of Src signaling leads to the destabilization of MdmX that is dependent on the RING (Really Interesting New Gene) domain of MdmX. Treatment with a small molecule inhibitor of neddylation, MLN4924, results in the activation of Ataxia Telangiectasia Mutated (ATM). ATM phosphorylates Mdm2, converting Mdm2 to a ubiquitinating enzyme which leads to the destabilization of MdmX. These data show how distinct signaling pathways engage neddylating or ubiquitinating activities and impact the Mdm2-MdmX axis.
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Affiliation(s)
- Paula M Hauck
- Department of Pediatrics, Herman B Wells Center for Pediatrics Research, Indianapolis, Indiana, 46202, United States of America
| | - Eric R Wolf
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana, 46202, United States of America
| | - David J Olivos
- Department of Pediatrics, Herman B Wells Center for Pediatrics Research, Indianapolis, Indiana, 46202, United States of America
| | - Ciaran P McAtarsney
- Department of Pediatrics, Herman B Wells Center for Pediatrics Research, Indianapolis, Indiana, 46202, United States of America
| | - Lindsey D Mayo
- Department of Pediatrics, Herman B Wells Center for Pediatrics Research, Indianapolis, Indiana, 46202, United States of America.,Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana, 46202, United States of America.,Indiana University Simon Cancer Center, Indiana University School of Medicine, Indianapolis, Indiana, 46202, United States of America
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42
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Saadatzadeh MR, Elmi AN, Pandya PH, Bijangi-Vishehsaraei K, Ding J, Stamatkin CW, Cohen-Gadol AA, Pollok KE. The Role of MDM2 in Promoting Genome Stability versus Instability. Int J Mol Sci 2017; 18:ijms18102216. [PMID: 29065514 PMCID: PMC5666895 DOI: 10.3390/ijms18102216] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Revised: 10/06/2017] [Accepted: 10/11/2017] [Indexed: 02/07/2023] Open
Abstract
In cancer, the mouse double minute 2 (MDM2) is an oncoprotein that contributes to the promotion of cell growth, survival, invasion, and therapeutic resistance. The impact of MDM2 on cell survival versus cell death is complex and dependent on levels of MDM2 isoforms, p53 status, and cellular context. Extensive investigations have demonstrated that MDM2 protein–protein interactions with p53 and other p53 family members (p63 and p73) block their ability to function as transcription factors that regulate cell growth and survival. Upon genotoxic insults, a dynamic and intricately regulated DNA damage response circuitry is activated leading to release of p53 from MDM2 and activation of cell cycle arrest. What ensues following DNA damage, depends on the extent of DNA damage and if the cell has sufficient DNA repair capacity. The well-known auto-regulatory loop between p53-MDM2 provides an additional layer of control as the cell either repairs DNA damage and survives (i.e., MDM2 re-engages with p53), or undergoes cell death (i.e., MDM2 does not re-engage p53). Furthermore, the decision to live or die is also influenced by chromatin-localized MDM2 which directly interacts with the Mre11-Rad50-Nbs1 complex and inhibits DNA damage-sensing giving rise to the potential for increased genome instability and cellular transformation.
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Affiliation(s)
- M Reza Saadatzadeh
- Department of Pediatrics (Division of Hematology/Oncology), Indianapolis, IN 46202, USA.
- Herman B. Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN 46202, USA.
- Herman B. Wells Center for Pediatric Research, Indiana University Simon Cancer Center, 1044 West Walnut Street R4 302, Indianapolis, IN 46202-5525, USA.
| | - Adily N Elmi
- Herman B. Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN 46202, USA.
| | - Pankita H Pandya
- Department of Pediatrics (Division of Hematology/Oncology), Indianapolis, IN 46202, USA.
| | | | - Jixin Ding
- Department of Pediatrics (Division of Hematology/Oncology), Indianapolis, IN 46202, USA.
- Herman B. Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN 46202, USA.
- Herman B. Wells Center for Pediatric Research, Indiana University Simon Cancer Center, 1044 West Walnut Street R4 302, Indianapolis, IN 46202-5525, USA.
| | - Christopher W Stamatkin
- Herman B. Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN 46202, USA.
- Herman B. Wells Center for Pediatric Research, Indiana University Simon Cancer Center, 1044 West Walnut Street R4 302, Indianapolis, IN 46202-5525, USA.
| | | | - Karen E Pollok
- Department of Pediatrics (Division of Hematology/Oncology), Indianapolis, IN 46202, USA.
- Herman B. Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN 46202, USA.
- Herman B. Wells Center for Pediatric Research, Indiana University Simon Cancer Center, 1044 West Walnut Street R4 302, Indianapolis, IN 46202-5525, USA.
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43
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Hong SY. DNA damage response is hijacked by human papillomaviruses to complete their life cycle. J Zhejiang Univ Sci B 2017; 18:215-232. [PMID: 28271657 DOI: 10.1631/jzus.b1600306] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The DNA damage response (DDR) is activated when DNA is altered by intrinsic or extrinsic agents. This pathway is a complex signaling network and plays important roles in genome stability, tumor transformation, and cell cycle regulation. Human papillomaviruses (HPVs) are the main etiological agents of cervical cancer. Cervical cancer ranks as the fourth most common cancer among women and the second most frequent cause of cancer-related death worldwide. Over 200 types of HPVs have been identified and about one third of these infect the genital tract. The HPV life cycle is associated with epithelial differentiation. Recent studies have shown that HPVs deregulate the DDR to achieve a productive life cycle. In this review, I summarize current findings about how HPVs mediate the ataxia-telangiectasia mutated kinase (ATM) and the ATM-and RAD3-related kinase (ATR) DDRs, and focus on the roles that ATM and ATR signalings play in HPV viral replication. In addition, I demonstrate that the signal transducer and activator of transcription-5 (STAT)-5, an important immune regulator, can promote ATM and ATR activations through different mechanisms. These findings may provide novel opportunities for development of new therapeutic targets for HPV-related cancers.
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Affiliation(s)
- Shi-Yuan Hong
- Department of Microbiology-Immunology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
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44
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Tackmann NR, Zhang Y. Mouse modelling of the MDM2/MDMX-p53 signalling axis. J Mol Cell Biol 2017; 9:34-44. [PMID: 28096294 PMCID: PMC5907827 DOI: 10.1093/jmcb/mjx006] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Accepted: 01/12/2017] [Indexed: 01/10/2023] Open
Abstract
It is evident that p53 activity is critical for tumour prevention and stress response through its transcriptional activation of genes affecting cellular senescence, apoptosis, cellular metabolism, and DNA repair. The regulation of p53 is highly complex, and MDM2 and MDMX are thought to be critical for deciding the fate of p53, both through inhibitory binding and post-translational modification. Many mouse models have been generated to study the regulation of p53 in vivo, and they have altered our interpretations of how p53 is regulated by MDM2 and MDMX. Although MDM2 is absolutely required for p53 regulation, certain functions are dispensable under unstressed conditions, including the ability of MDM2 to degrade p53. MDMX, on the other hand, may only be required in select situations, like embryogenesis. These models have also clarified how cellular stress signals modify the p53-inhibiting activities of MDM2 and MDMX in vivo. It is clear that more work will need to be performed to further understand the contexts for each of these signals and the requirements of various MDM2 and MDMX functions. Here, we will discuss what we have learned from mouse modelling of MDM2 and MDMX and underscore the ways in which these models could inform future therapies.
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Affiliation(s)
- Nicole R Tackmann
- Department of Radiation Oncology, Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27514, USA.,Curriculum in Genetics and Molecular Biology, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC 27514, USA
| | - Yanping Zhang
- Department of Radiation Oncology, Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27514, USA.,Jiangsu Center for the Collaboration and Innovation of Cancer Biotherapy, Cancer Institute, Xuzhou Medical College, Xuzhou 221002, China
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45
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Chen Y, Wang YG, Li Y, Sun XX, Dai MS. Otub1 stabilizes MDMX and promotes its proapoptotic function at the mitochondria. Oncotarget 2017; 8:11053-11062. [PMID: 28035068 PMCID: PMC5355245 DOI: 10.18632/oncotarget.14278] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Accepted: 12/20/2016] [Indexed: 11/25/2022] Open
Abstract
Otub1 regulates p53 stability and activity via non-canonical inhibition of UbcH5, the MDM2 cognate ubiquitin-conjugating enzyme (E2). However, whether Otub1 regulates MDMX stability and activity is not clear. Here we report that Otub1 also suppresses MDM2-mediated MDMX ubiquitination in cells and in vitro, independently of its deubiquitinating enzyme activity. Consequently, overexpression of Otub1 markedly stabilized MDMX and increased its levels, whereas knockdown of Otub1 reduced the levels of MDMX. Interestingly, MDMX induced by Otub1 can localize to mitochondria in addition to the cytosol, enhance p53 phosphorylation at S46 (p53S46P) and promote mitochondria-mediated apoptotic pathway. Knockdown of MDMX reduced Otub1-induced p53S46P, which was shown to be critical for p53's mitochondrial function and apoptotic activity. Furthermore, Otub1 promotes UV-irradiation-induced p53S46P and apoptosis, which can be significantly inhibited by MDMX depletion. Together, these results suggest that Otub1 stabilizes MDMX and promotes p53S46P and mitochondria-mediated apoptosis, providing an alternative mechanism of Otub1's role in apoptosis.
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Affiliation(s)
- Yingxiao Chen
- Department of Molecular and Medical Genetics, School of Medicine, and The OHSU Knight Cancer Institute, Oregon Health and Science University, Portland, OR 97239, USA
| | - Yue-Gang Wang
- Department of Molecular and Medical Genetics, School of Medicine, and The OHSU Knight Cancer Institute, Oregon Health and Science University, Portland, OR 97239, USA
| | - Yuhuang Li
- Department of Molecular and Medical Genetics, School of Medicine, and The OHSU Knight Cancer Institute, Oregon Health and Science University, Portland, OR 97239, USA
| | - Xiao-Xin Sun
- Department of Molecular and Medical Genetics, School of Medicine, and The OHSU Knight Cancer Institute, Oregon Health and Science University, Portland, OR 97239, USA
| | - Mu-Shui Dai
- Department of Molecular and Medical Genetics, School of Medicine, and The OHSU Knight Cancer Institute, Oregon Health and Science University, Portland, OR 97239, USA
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46
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Zhou X, Cao B, Lu H. Negative auto-regulators trap p53 in their web. J Mol Cell Biol 2017; 9:62-68. [PMID: 28069666 PMCID: PMC5907828 DOI: 10.1093/jmcb/mjx001] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Revised: 11/14/2016] [Accepted: 01/06/2017] [Indexed: 01/07/2023] Open
Abstract
The transcriptional factor p53 activates the expression of a myriad of target genes involving a complicated signalling network, resulting in various cellular outcomes, such as growth arrest, senescence, apoptosis, and metabolic changes, and leading to consequent suppression of tumour growth and progression. Because of the profoundly adverse effect of p53 on growth and proliferation of cancer cells, several feedback mechanisms have been employed by the cells to constrain p53 activity. Two major antagonists MDM2 and MDMX (the long forms) are transcriptionally induced by p53, but in return block p53 activity, forming a negative feedback circuit and rendering chemoresistance of several cancer cells. However, they are not alone, as cancer cells also employ other proteins encoded by p53 target genes to inhibit p53 activity at transcriptional, translational, and posttranslational levels. This essay is thus composed to review a recent progress in understanding the mechanisms for how cancer cells hijack the p53 autoregulation by these proteins for their growth advantage and to discuss the clinical implications of these autoregulatory loops.
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Affiliation(s)
- Xiang Zhou
- Fudan University Shanghai Cancer Center and the Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, China
| | - Bo Cao
- Department of Biochemistry & Molecular Biology and Tulane Cancer Center, Tulane University School of Medicine, New Orleans, LA 70112, USA
| | - Hua Lu
- Department of Biochemistry & Molecular Biology and Tulane Cancer Center, Tulane University School of Medicine, New Orleans, LA 70112, USA
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47
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Neault M, Couteau F, Bonneau É, De Guire V, Mallette FA. Molecular Regulation of Cellular Senescence by MicroRNAs: Implications in Cancer and Age-Related Diseases. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2017; 334:27-98. [DOI: 10.1016/bs.ircmb.2017.04.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
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48
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Xie X, He G, Siddik ZH. Functional Activation of Mutant p53 by Platinum Analogues in Cisplatin-Resistant Cells Is Dependent on Phosphorylation. Mol Cancer Res 2016; 15:328-339. [PMID: 28031409 DOI: 10.1158/1541-7786.mcr-16-0257-t] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Revised: 11/22/2016] [Accepted: 11/29/2016] [Indexed: 02/01/2023]
Abstract
Dysfunctionality of the p53 tumor suppressor is a major cause of therapeutic drug resistance in cancer. Recently, we reported that mutant, but otherwise functional, p53v172F was inactivated in cisplatin-resistant 2780CP/Cl-16 and 2780CP/Cl-24 human ovarian tumor cells by increased recruitment of the inhibitor MDM4. The current study demonstrates that, unlike cisplatin, platinum analogues oxaliplatin and DACH-diacetato-dichloro-Pt(IV) (DAP) strongly stabilize and activate p53v172F in resistant cells, as indicated by prolonged p53 half-life and transactivation of targets p21 (CDKN1A) and MDM2. This increase in MDM2 reduced MDM4 levels in cell lysates as well as the p53 immunocomplex and prevented reversion of p53 to the inactive p53-MDM2-MDM4-bound state. Phosphorylation of p53 at Ser15 was demonstrated by all three drugs in sensitive A2780 and corresponding resistant 2780CP/Cl-16 and 2780CP/Cl-24 cell lines. However, cisplatin induced Ser20 phosphorylation in A2780 cells only, but not in resistant cells; in contrast, both DAP and oxaliplatin induced this phosphorylation in all three cell lines. The inference that Ser20 phosphorylation is more important for p53 activation was confirmed by ectopic expression of a phosphomimetic (S20D) mutant p53 that displayed reduced binding, relative to wild-type p53, to both MDM2 and MDM4 in p53-knockout A2780 cells. In consonance, temporal studies demonstrated drug-induced Ser15 phosphorylation coincided with p53 stabilization, whereas Ser20 phosphorylation coincided with p53 transactivation.Implications: Cisplatin fails to activate the pathway involved in phosphorylating mutant p53v172F at Ser20 in resistant cells, but this phosphorylation is restored by oxaliplatin and DAP that reactivates p53 function and circumvents cisplatin resistance. Mol Cancer Res; 15(3); 328-39. ©2016 AACR.
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Affiliation(s)
- Xiaolei Xie
- Department of Experimental Therapeutics, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Guangan He
- Department of Experimental Therapeutics, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Zahid H Siddik
- Department of Experimental Therapeutics, The University of Texas MD Anderson Cancer Center, Houston, Texas.
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49
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Phosphorylation of the Mdm2 oncoprotein by the c-Abl tyrosine kinase regulates p53 tumor suppression and the radiosensitivity of mice. Proc Natl Acad Sci U S A 2016; 113:15024-15029. [PMID: 27956626 DOI: 10.1073/pnas.1611798114] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The p53 tumor suppressor acts as a guardian of the genome by preventing the propagation of DNA damage-induced breaks and mutations to subsequent generations of cells. We have previously shown that phosphorylation of the Mdm2 oncoprotein at Ser394 by the ATM kinase is required for robust p53 stabilization and activation in cells treated with ionizing radiation, and that loss of Mdm2 Ser394 phosphorylation leads to spontaneous tumorigenesis and radioresistance in Mdm2S394A mice. Previous in vitro data indicate that the c-Abl kinase phosphorylates Mdm2 at the neighboring residue (Tyr393) in response to DNA damage to regulate p53-dependent apoptosis. In this present study, we have generated an Mdm2 mutant mouse (Mdm2Y393F) to determine whether c-Abl phosphorylation of Mdm2 regulates the p53-mediated DNA damage response or p53 tumor suppression in vivo. The Mdm2Y393F mice develop accelerated spontaneous and oncogene-induced tumors, yet display no defects in p53 stabilization and activity following acute genotoxic stress. Although apoptosis is unaltered in these mice, they recover more rapidly from radiation-induced bone marrow ablation and are more resistant to whole-body radiation-induced lethality. These data reveal an in vivo role for c-Abl phosphorylation of Mdm2 in regulation of p53 tumor suppression and bone marrow failure. However, c-Abl phosphorylation of Mdm2 Tyr393 appears to play a lesser role in governing Mdm2-p53 signaling than ATM phosphorylation of Mdm2 Ser394. Furthermore, the effects of these phosphorylation events on p53 regulation are not additive, as Mdm2Y393F/S394A mice and Mdm2S394A mice display similar phenotypes.
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50
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Carr MI, Jones SN. Regulation of the Mdm2-p53 signaling axis in the DNA damage response and tumorigenesis. Transl Cancer Res 2016; 5:707-724. [PMID: 28690977 PMCID: PMC5501481 DOI: 10.21037/tcr.2016.11.75] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The p53 tumor suppressor acts as a guardian of the genome in mammalian cells undergoing DNA double strand breaks induced by a various forms of cell stress, including inappropriate growth signals or ionizing radiation. Following damage, p53 protein levels become greatly elevated in cells and p53 functions primarily as a transcription factor to regulate the expression a wide variety of genes that coordinate this DNA damage response. In cells undergoing high amounts of DNA damage, p53 can promote apoptosis, whereas in cells undergoing less damage, p53 promotes senescence or transient cell growth arrest and the expression of genes involved in DNA repair, depending upon the cell type and level of damage. Failure of the damaged cell to undergo growth arrest or apoptosis, or to respond to the DNA damage by other p53-coordinated mechanisms, can lead to inappropriate cell growth and tumorigenesis. In cells that have successfully responded to genetic damage, the amount of p53 present in the cell must return to basal levels in order for the cell to resume normal growth and function. Although regulation of p53 levels and function is coordinated by many proteins, it is now widely accepted that the master regulator of p53 is Mdm2. In this review, we discuss the role(s) of p53 in the DNA damage response and in tumor suppression, and how post-translational modification of Mdm2 regulates the Mdm2-p53 signaling axis to govern p53 activities in the cell.
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Affiliation(s)
- Michael I Carr
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Stephen N Jones
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, Worcester, MA 01655, USA
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