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Nguyen A, Mustafa AHM, Leydecker AK, Halilovic M, Murr J, Butter F, Krämer OH. The protein phosphatase-2A subunit PR130 is involved in the formation of cytotoxic protein aggregates in pancreatic ductal adenocarcinoma cells. Cell Commun Signal 2024; 22:217. [PMID: 38570831 PMCID: PMC10993613 DOI: 10.1186/s12964-024-01597-8] [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: 11/11/2023] [Accepted: 03/26/2024] [Indexed: 04/05/2024] Open
Abstract
As a major source of cellular serine and threonine phosphatase activity, protein phosphatase-2A (PP2A) modulates signaling pathways in health and disease. PP2A complexes consist of catalytic, scaffolding, and B-type subunits. Seventeen PP2A B-type subunits direct PP2A complexes to selected substrates. It is ill-defined how PP2A B-type subunits determine the growth and drug responsiveness of tumor cells. Pancreatic ductal adenocarcinoma (PDAC) is a disease with poor prognosis. We analyzed the responses of murine and human mesenchymal and epithelial PDAC cells to the specific PP2A inhibitor phendione. We assessed protein levels by immunoblot and proteomics and cell fate by flow cytometry, confocal microscopy, and genetic manipulation. We show that murine mesenchymal PDAC cells express significantly higher levels of the PP2A B-type subunit PR130 than epithelial PDAC cells. This overexpression of PR130 is associated with a dependency of such metastasis-prone cells on the catalytic activity of PP2A. Phendione induces apoptosis and an accumulation of cytotoxic protein aggregates in murine mesenchymal and human PDAC cells. These processes occur independently of the frequently mutated tumor suppressor p53. Proteomic analyses reveal that phendione upregulates the chaperone HSP70 in mesenchymal PDAC cells. Inhibition of HSP70 promotes phendione-induced apoptosis and phendione promotes a proteasomal degradation of PR130. Genetic elimination of PR130 sensitizes murine and human PDAC cells to phendione-induced apoptosis and protein aggregate formation. These data suggest that the PP2A-PR130 complex dephosphorylates and thereby prevents the aggregation of proteins in tumor cells.
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Affiliation(s)
- Alexandra Nguyen
- Institute of Toxicology, University Medical Center of the Johannes Gutenberg University Mainz, Obere Zahlbacher St. 67, 55131, Mainz, Germany
| | - Al-Hassan M Mustafa
- Institute of Toxicology, University Medical Center of the Johannes Gutenberg University Mainz, Obere Zahlbacher St. 67, 55131, Mainz, Germany
- Department of Zoology, Faculty of Science, Aswan University, Aswan, Egypt
| | - Alessa K Leydecker
- Institute of Toxicology, University Medical Center of the Johannes Gutenberg University Mainz, Obere Zahlbacher St. 67, 55131, Mainz, Germany
| | - Melisa Halilovic
- Institute of Toxicology, University Medical Center of the Johannes Gutenberg University Mainz, Obere Zahlbacher St. 67, 55131, Mainz, Germany
| | - Janine Murr
- Medical Clinic and Polyclinic II, Klinikum Rechts Der Isar, Technical University Munich, 81675, Munich, Germany
| | - Falk Butter
- Institute of Molecular Biology (IMB), Ackermannweg 4, 55128, Mainz, Germany
- Federal Research Institute for Animal Health, Südufer 10, 17493, Greifswald, Insel Riems, Germany
| | - Oliver H Krämer
- Institute of Toxicology, University Medical Center of the Johannes Gutenberg University Mainz, Obere Zahlbacher St. 67, 55131, Mainz, Germany.
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2
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Sun G. Death and survival from executioner caspase activation. Semin Cell Dev Biol 2024; 156:66-73. [PMID: 37468421 DOI: 10.1016/j.semcdb.2023.07.005] [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: 04/08/2023] [Revised: 07/11/2023] [Accepted: 07/12/2023] [Indexed: 07/21/2023]
Abstract
Executioner caspases are evolutionarily conserved regulators of cell death under apoptotic stress. Activated executioner caspases drive apoptotic cell death through cleavage of diverse protein substrates or pyroptotic cell death in the presence of gasdermin E. On the other hand, activation of executioner caspases can also trigger pro-survival and pro-proliferation signals. In recent years, a growing body of studies have demonstrated that cells can survive from executioner caspase activation in response to stress and that the survivors undergo molecular and phenotypic alterations. This review focuses on death and survival from executioner caspase activation, summarizing the role of executioner caspases in apoptotic and pyroptotic cell death and discussing the potential mechanism and consequences of survival from stress-induced executioner caspase activation.
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Affiliation(s)
- Gongping Sun
- Key Laboratory of Experimental Teratology, Ministry of Education, Department of Histology and Embryology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, Shandong 250012, China.
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3
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Erdemir Sayan S, Sreekumar R, Bhome R, Mirnezami A, Yagci T, Sayan AE. ERCC1 abundance is an indicator of DNA repair-apoptosis decision upon DNA damage. Cell Death Discov 2024; 10:47. [PMID: 38272916 PMCID: PMC10810800 DOI: 10.1038/s41420-024-01817-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2023] [Revised: 01/06/2024] [Accepted: 01/12/2024] [Indexed: 01/27/2024] Open
Abstract
DNA repair is essential for successful propagation of genetic material and fidelity of transcription. Nucleotide excision repair (NER) is one of the earliest DNA repair mechanisms, functionally conserved from bacteria to human. The fact that number of NER genes vary significantly between prokaryotes and metazoans gives the insight that NER proteins have evolved to acquire additional functions to combat challenges associated with a diploid genome, including being involved in the decision between DNA repair and apoptosis. However, no direct association between apoptosis and NER proteins has been shown to date. In this study, we induced apoptosis with a variety of agents, including oxaliplatin, doxorubicin and TRAIL, and observed changes in the abundance and molecular weight of NER complex proteins. Our results showed that XPA, XPC and ERCC1 protein levels change during DNA damage-induced apoptosis. Among these, ERCC1 decrease was observed as a pre-mitochondria depolarisation event which marks the "point of no return" in apoptosis signalling. ERCC1 decrease was due to proteasomal degradation upon lethal doses of oxaliplatin exposure. When ERCC1 protein was stabilised using proteasome inhibitors, the pro-apoptotic activity of oxaliplatin was attenuated. These results explain why clinical trials using proteasome inhibitors and platinum derivatives showed limited efficacy in carcinoma treatment and also the importance of how deep understanding of DNA repair mechanisms can improve cancer therapy.
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Affiliation(s)
- Sule Erdemir Sayan
- Department of Molecular Biology and Genetics, Gebze Technical University, Kocaeli, 41400, Turkey
| | - Rahul Sreekumar
- Cancer Sciences Unit, University of Southampton, Southampton General Hospital, Somers Cancer Research Building, Southampton, SO16 6YD, UK
| | - Rahul Bhome
- Cancer Sciences Unit, University of Southampton, Southampton General Hospital, Somers Cancer Research Building, Southampton, SO16 6YD, UK
| | - Alex Mirnezami
- Cancer Sciences Unit, University of Southampton, Southampton General Hospital, Somers Cancer Research Building, Southampton, SO16 6YD, UK
| | - Tamer Yagci
- Department of Molecular Biology and Genetics, Gebze Technical University, Kocaeli, 41400, Turkey
| | - A Emre Sayan
- Cancer Sciences Unit, University of Southampton, Southampton General Hospital, Somers Cancer Research Building, Southampton, SO16 6YD, UK.
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4
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Brockmueller A, Buhrmann C, Moravejolahkami AR, Shakibaei M. Resveratrol and p53: How are they involved in CRC plasticity and apoptosis? J Adv Res 2024:S2090-1232(24)00005-5. [PMID: 38190940 DOI: 10.1016/j.jare.2024.01.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Revised: 12/27/2023] [Accepted: 01/05/2024] [Indexed: 01/10/2024] Open
Abstract
BACKGROUND Colorectal cancer (CRC), which is mainly caused by epigenetic and lifestyle factors, is very often associated with functional plasticity during its development. In addition, the malignant plasticity of CRC cells underscores one of their survival abilities to functionally adapt to specific stresses, including inflammation, that occur during carcinogenesis. This leads to the generation of various subsets of cancer cells with phenotypic diversity and promotes epithelial-mesenchymal transition (EMT), formation of cancer cell stem cells (CSCs) and metabolic reprogramming. This can enhance cancer cell differentiation and facilitate tumorigenic potential, drug resistance and metastasis. AIM OF REVIEW The tumor protein p53 acts as one of the central suppressors of carcinogenesis by regulating its target genes, whose proteins are involved in the plasticity of cancer cells, autophagy, cell cycle, apoptosis, DNA repair. The aim of this review is to summarize the latest published research on resveratrol's effect in the prevention of CRC, its regulatory actions, specifically on the p53 pathway, and its treatment options. KEY SCIENTIFIC CONCEPTS OF REVIEW Resveratrol, a naturally occurring polyphenol, is a potent inducer of a variety of tumor-controlling. However, the underlying mechanisms linking the p53 signaling pathway to the functional anti-plasticity effect of resveratrol in CRC are still poorly understood. Therefore, this review discusses novel relationships between anti-cellular plasticity/heterogeneity, pro-apoptosis and modulation of tumor protein p53 signaling in CRC oncogenesis, as one of the crucial mechanisms by which resveratrol prevents malignant phenotypic changes leading to cell migration and drug resistance, thus improving the ongoing treatment of CRC.
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Affiliation(s)
- Aranka Brockmueller
- Chair of Vegetative Anatomy, Institute of Anatomy, Faculty of Medicine, Ludwig-Maximilians-University Munich, Pettenkoferstr. 11, D-80336 Munich, Germany
| | - Constanze Buhrmann
- Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Augsburg, Augsburg, Germany
| | - Amir Reza Moravejolahkami
- Department of Clinical Nutrition, School of Nutrition & Food Science, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Mehdi Shakibaei
- Chair of Vegetative Anatomy, Institute of Anatomy, Faculty of Medicine, Ludwig-Maximilians-University Munich, Pettenkoferstr. 11, D-80336 Munich, Germany.
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5
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Park HJ, Gregory MA, Zaberezhnyy V, Goodspeed A, Jordan CT, Kieft JS, DeGregori J. Therapeutic resistance in acute myeloid leukemia cells is mediated by a novel ATM/mTOR pathway regulating oxidative phosphorylation. eLife 2022; 11:e79940. [PMID: 36259537 PMCID: PMC9645811 DOI: 10.7554/elife.79940] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Accepted: 10/17/2022] [Indexed: 11/13/2022] Open
Abstract
While leukemic cells are susceptible to various therapeutic insults, residence in the bone marrow microenvironment typically confers protection from a wide range of drugs. Thus, understanding the unique molecular changes elicited by the marrow is of critical importance toward improving therapeutic outcomes. In this study, we demonstrate that aberrant activation of oxidative phosphorylation serves to induce therapeutic resistance in FLT3 mutant human AML cells challenged with FLT3 inhibitor drugs. Importantly, our findings show that AML cells are protected from apoptosis following FLT3 inhibition due to marrow-mediated activation of ATM, which in turn upregulates oxidative phosphorylation via mTOR signaling. mTOR is required for the bone marrow stroma-dependent maintenance of protein translation, with selective polysome enrichment of oxidative phosphorylation transcripts, despite FLT3 inhibition. To investigate the therapeutic significance of this finding, we tested the mTOR inhibitor everolimus in combination with the FLT3 inhibitor quizartinib in primary human AML xenograft models. While marrow resident AML cells were highly resistant to quizartinib alone, the addition of everolimus induced profound reduction in tumor burden and prevented relapse. Taken together, these data provide a novel mechanistic understanding of marrow-based therapeutic resistance and a promising strategy for improved treatment of FLT3 mutant AML patients.
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Affiliation(s)
- Hae J Park
- Department of Biochemistry and Molecular Genetics, School of Medicine, University of Colorado Anschutz Medical CampusAuroraUnited States
- Medical Scientist Training Program, University of Colorado Anschutz Medical CampusAuroraUnited States
| | - Mark A Gregory
- Department of Biochemistry and Molecular Genetics, School of Medicine, University of Colorado Anschutz Medical CampusAuroraUnited States
| | - Vadym Zaberezhnyy
- Department of Biochemistry and Molecular Genetics, School of Medicine, University of Colorado Anschutz Medical CampusAuroraUnited States
| | - Andrew Goodspeed
- Department of Pharmacology, University of Colorado Anschutz Medical CampusAuroraUnited States
- University of Colorado Comprehensive Cancer Center, University of Colorado Anschutz Medical CampusAuroraUnited States
| | - Craig T Jordan
- Department of Medicine, Section of Hematology, University of Colorado Anschutz Medical CampusAuroraUnited States
| | - Jeffrey S Kieft
- Department of Biochemistry and Molecular Genetics, School of Medicine, University of Colorado Anschutz Medical CampusAuroraUnited States
| | - James DeGregori
- Department of Biochemistry and Molecular Genetics, School of Medicine, University of Colorado Anschutz Medical CampusAuroraUnited States
- University of Colorado Comprehensive Cancer Center, University of Colorado Anschutz Medical CampusAuroraUnited States
- Department of Medicine, Section of Hematology, University of Colorado Anschutz Medical CampusAuroraUnited States
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6
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Wu W, Dong J, Gou H, Geng R, Yang X, Chen D, Xiang B, Zhang Z, Ren S, Chen L, Liu J. EGCG synergizes the therapeutic effect of irinotecan through enhanced DNA damage in human colorectal cancer cells. J Cell Mol Med 2021; 25:7913-7921. [PMID: 34132471 PMCID: PMC8358867 DOI: 10.1111/jcmm.16718] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2021] [Revised: 05/15/2021] [Accepted: 05/26/2021] [Indexed: 01/30/2023] Open
Abstract
Irinotecan is a kind of alkaloid with antitumour activity, but its low solubility and high toxicity limit its application. Epigallocatechin‐3‐gallate (EGCG) is one of the main bioactive components in tea. The epidemiological investigation and animal and cell experiments show that EGCG has a preventive and therapeutic effect on many kinds of tumours. Here, colorectal cancer cells RKO and HCT116 were employed, and the CCK8 proliferation test was used to screen the appropriate concentration of EGCG and irinotecan, and the effects of single and/or combined drugs on migration, invasion, DNA damage, cell cycle and autophagy of tumour cells were investigated. The results showed that EGCG combined with irinotecan (0.5 μmol L−) not only had a stronger inhibitory effect on tumour cells than EGCG or irinotecan alone but also prevented tumour cell migration and invasion. EGCG alone did not cause DNA damage in colorectal cancer cells, but its combination with irinotecan could induce S or G2 phase arrest by inhibiting topoisomerase I to cause more extensive DNA damage. EGCG also induced apoptosis by promoting autophagy with irinotecan synergistically. These results indicated that EGCG in combination with irinotecan could be a promising strategy for colorectal cancer.
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Affiliation(s)
- Wenbing Wu
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences & Forensic Medicine, Sichuan University, Chengdu, China.,Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Southwest Medical University, Luzhou, China
| | - Jingying Dong
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences & Forensic Medicine, Sichuan University, Chengdu, China
| | - Hui Gou
- Department of Pharmacy, The Affiliated Hospital of Southwest Medical University, Luzhou, China
| | - Ruiman Geng
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences & Forensic Medicine, Sichuan University, Chengdu, China
| | - Xiaolong Yang
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences & Forensic Medicine, Sichuan University, Chengdu, China
| | - Dan Chen
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences & Forensic Medicine, Sichuan University, Chengdu, China
| | - Bin Xiang
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences & Forensic Medicine, Sichuan University, Chengdu, China
| | - Zhengkun Zhang
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences & Forensic Medicine, Sichuan University, Chengdu, China
| | - Sichong Ren
- State Key Laboratory of Quality Evaluation of Traditional Chinese Medicine, Sichuan Academy of Traditional Chinese Medicine, Chengdu, China
| | - Lihong Chen
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences & Forensic Medicine, Sichuan University, Chengdu, China
| | - Ji Liu
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences & Forensic Medicine, Sichuan University, Chengdu, China
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7
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Hashemi S, Hosseini SM, Ghalyanchilangeroudi A, Sheikhi N. Transcriptome based analysis of apoptosis genes in chickens co-infected with avian infectious bronchitis virus and pathogenic Escherichia coli. IRANIAN JOURNAL OF MICROBIOLOGY 2021; 13:17-22. [PMID: 33889358 PMCID: PMC8043830 DOI: 10.18502/ijm.v13i1.5487] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
BACKGROUND AND OBJECTIVES Infection with Infectious bronchitis virus (IBV) and avian pathogenic Escherichia coli (APEC) is an important respiratory infection worldwide. Apoptosis is a physiological process of cell death that occurs as part of normal development and responds to a variety of physiological and pathophysiological stimuli. The identification of molecular mechanisms of action or inaction of key apoptotic proteins is important. This study aimed to investigate apoptotic related genes in the trachea tissue of infected (IBV variant 2, and APEC serotype O78: K80) SPF chickens group compared to the control group. MATERIALS AND METHODS Forty SPF chickens was divided into 2 groups. Differential transcriptional profile in the infected SPF chickens trachea tissue was compared to those of control group in the early stage of infection by Illumina RNA-seq technique paired-end and strand-specific sequencing. Differentially expressed genes (DEGs) of transcriptome profiling of the trachea from the infected group were identified. Gene ontology category, KEGG pathway, and STRING analysis were analyzed to identify relationships among differentially expressed genes. RESULTS Twenty-eight apoptotic genes were identified. They consisted of six pathways related to cell death: the extrinsic pathway, intrinsic pathway, endoplasmic reticulum stress pathway, MAPK signaling pathway, and cell death by NFkB and activates mTOR pathway and some regulator and apoptosis inhibitors. CONCLUSION All of the apoptotic genes in our study were up-regulated. Among these genes, the more fold change value was for TRADD and BCL2A1 genes, and the less fold change value was for MAP3K14, NFKB1, PIK3CB, and ITPR2 genes.
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Affiliation(s)
- Shabnam Hashemi
- Department of Microbiology and Microbial Biotechnology, Faculty of Life Sciences and Biotechnology, Shahid Beheshti University, Tehran, Iran
| | - Seyed Masoud Hosseini
- Department of Microbiology and Microbial Biotechnology, Faculty of Life Sciences and Biotechnology, Shahid Beheshti University, Tehran, Iran
| | - Arash Ghalyanchilangeroudi
- Department of Microbiology and Immunology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran
| | - Nariman Sheikhi
- Department of Clinical Sciences, College of Veterinary, Tehran Sciences and Research Branch, Islamic Azad University, Tehran, Iran
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8
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Rieunier G, Wu X, Harris LE, Mills JV, Nandakumar A, Colling L, Seraia E, Hatch SB, Ebner DV, Folkes LK, Weyer-Czernilofsky U, Bogenrieder T, Ryan AJ, Macaulay VM. Targeting IGF Perturbs Global Replication through Ribonucleotide Reductase Dysfunction. Cancer Res 2021; 81:2128-2141. [PMID: 33509941 DOI: 10.1158/0008-5472.can-20-2860] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2020] [Revised: 12/17/2020] [Accepted: 01/22/2021] [Indexed: 11/16/2022]
Abstract
Inhibition of IGF receptor (IGF1R) delays repair of radiation-induced DNA double-strand breaks (DSB), prompting us to investigate whether IGF1R influences endogenous DNA damage. Here we demonstrate that IGF1R inhibition generates endogenous DNA lesions protected by 53BP1 bodies, indicating under-replicated DNA. In cancer cells, inhibition or depletion of IGF1R delayed replication fork progression accompanied by activation of ATR-CHK1 signaling and the intra-S-phase checkpoint. This phenotype reflected unanticipated regulation of global replication by IGF1 mediated via AKT, MEK/ERK, and JUN to influence expression of ribonucleotide reductase (RNR) subunit RRM2. Consequently, inhibition or depletion of IGF1R downregulated RRM2, compromising RNR function and perturbing dNTP supply. The resulting delay in fork progression and hallmarks of replication stress were rescued by RRM2 overexpression, confirming RRM2 as the critical factor through which IGF1 regulates replication. Suspecting existence of a backup pathway protecting from toxic sequelae of replication stress, targeted compound screens in breast cancer cells identified synergy between IGF inhibition and ATM loss. Reciprocal screens of ATM-proficient/deficient fibroblasts identified an IGF1R inhibitor as the top hit. IGF inhibition selectively compromised growth of ATM-null cells and spheroids and caused regression of ATM-null xenografts. This synthetic-lethal effect reflected conversion of single-stranded lesions in IGF-inhibited cells into toxic DSBs upon ATM inhibition. Overall, these data implicate IGF1R in alleviating replication stress, and the reciprocal IGF:ATM codependence we identify provides an approach to exploit this effect in ATM-deficient cancers. SIGNIFICANCE: This study identifies regulation of ribonucleotide reductase function and dNTP supply by IGFs and demonstrates that IGF axis blockade induces replication stress and reciprocal codependence on ATM. GRAPHICAL ABSTRACT: http://cancerres.aacrjournals.org/content/canres/81/8/2128/F1.large.jpg.
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Affiliation(s)
| | - Xiaoning Wu
- Department of Oncology, University of Oxford, Oxford, United Kingdom
| | - Letitia E Harris
- CRUK/MRC Oxford Institute for Radiation Oncology, University of Oxford, Oxford, United Kingdom
| | - Jack V Mills
- Department of Oncology, University of Oxford, Oxford, United Kingdom
| | - Ashwin Nandakumar
- Department of Oncology, University of Oxford, Oxford, United Kingdom
| | - Laura Colling
- Department of Oncology, Weatherall Institute of Molecular Medicine, Oxford, United Kingdom
| | - Elena Seraia
- Target Discovery Institute, University of Oxford, Oxford, United Kingdom
| | - Stephanie B Hatch
- Target Discovery Institute, University of Oxford, Oxford, United Kingdom
| | - Daniel V Ebner
- Target Discovery Institute, University of Oxford, Oxford, United Kingdom
| | - Lisa K Folkes
- CRUK/MRC Oxford Institute for Radiation Oncology, University of Oxford, Oxford, United Kingdom
| | | | - Thomas Bogenrieder
- AMAL Therapeutics, Geneva, Switzerland
- Department of Urology, University Hospital Grosshadern, Ludwig-Maximilians-University, Munich, Germany
| | - Anderson J Ryan
- CRUK/MRC Oxford Institute for Radiation Oncology, University of Oxford, Oxford, United Kingdom
| | - Valentine M Macaulay
- Department of Oncology, University of Oxford, Oxford, United Kingdom.
- Oxford Cancer and Haematology Centre, Oxford University Hospitals NHS Foundation Trust, Churchill Hospital, Oxford, United Kingdom
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9
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Sarkar A, Gandhi V. Activation of ATM kinase by ROS generated during ionophore-induced mitophagy in human T and B cell malignancies. Mol Cell Biochem 2020; 476:417-423. [PMID: 32996079 DOI: 10.1007/s11010-020-03917-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 09/15/2020] [Indexed: 01/07/2023]
Abstract
Ataxia telangiectasia mutated (ATM), a critical DNA damage sensor, also possesses non-nuclear functions owing to its presence in extra-nuclear compartments, including peroxisomes, lysosomes, and mitochondria. ATM is frequently altered in several human cancers. Recently, we and others have shown that loss of ATM is associated with defective mitochondrial autophagy (mitophagy) in ataxia-telangiectasia (A-T) fibroblasts and B-cell lymphomas. Further, we reported that ATM protein but not ATM kinase activity is required for mitophagy. However, the mechanism of ATM kinase activation during ionophore-induced mitophagy is unknown. In the work reported here, using several ionophores in A-T and multiple T-cell and B-cell lymphoma cell lines, we show that ionophore-induced mitophagy triggers oxidative stress-induced ATMSer1981 phosphorylation through ROS activation, which is different from neocarzinostatin-induced activation of ATMSer1981, Smc1Ser966, and Kap1Ser824. We used A-T cells overexpressed with WT or S1981A (auto-phosphorylation dead) ATM plasmids and show that ATM is activated by ROS-induced oxidative stress emanating from ionophore-induced mitochondrial damage and mitophagy. The antioxidants N-acetylcysteine and glutathione significantly inhibited ROS production and ATMSer1981 phosphorylation but failed to inhibit mitophagy as determined by retroviral infection with mt-mKeima construct followed by lysosomal dual-excitation ratiometric pH measurements. Our data suggest that while ATM kinase does not participate in mitophagy, it is activated via elevated ROS.
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Affiliation(s)
- Aloke Sarkar
- Department of Experimental Therapeutics, The University of Texas MD Anderson Cancer Center, Unit 1950, 1901 East Road, Houston, TX, 77054, USA.
| | - Varsha Gandhi
- Department of Experimental Therapeutics, The University of Texas MD Anderson Cancer Center, Unit 1950, 1901 East Road, Houston, TX, 77054, USA. .,Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, TX, USA. .,The University of Texas MD Anderson Cancer Center UT Health Graduate School of Biomedical Sciences, Houston, TX, USA.
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10
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Yang J, Wang T, Zhao L, Rajasekhar VK, Joshi S, Andreou C, Pal S, Hsu HT, Zhang H, Cohen IJ, Huang R, Hendrickson RC, Miele MM, Pei W, Brendel MB, Healey JH, Chiosis G, Kircher MF. Gold/alpha-lactalbumin nanoprobes for the imaging and treatment of breast cancer. Nat Biomed Eng 2020; 4:686-703. [PMID: 32661307 PMCID: PMC8255032 DOI: 10.1038/s41551-020-0584-z] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Accepted: 06/11/2020] [Indexed: 02/03/2023]
Abstract
Theranostic agents should ideally be renally cleared and biodegradable. Here, we report the synthesis, characterization and theranostic applications of fluorescent ultrasmall gold quantum clusters that are stabilized by the milk metalloprotein alpha-lactalbumin. We synthesized three types of these nanoprobes that together display fluorescence across the visible and near-infrared spectra when excited at a single wavelength through optical colour coding. In live tumour-bearing mice, the near-infrared nanoprobe generates contrast for fluorescence, X-ray computed tomography and magnetic resonance imaging, and exhibits long circulation times, low accumulation in the reticuloendothelial system, sustained tumour retention, insignificant toxicity and renal clearance. An intravenously administrated near-infrared nanoprobe with a large Stokes shift facilitated the detection and image-guided resection of breast tumours in vivo using a smartphone with modified optics. Moreover, the partially unfolded structure of alpha-lactalbumin in the nanoprobe helps with the formation of an anti-cancer lipoprotein complex with oleic acid that triggers the inhibition of the MAPK and PI3K-AKT pathways, immunogenic cell death and the recruitment of infiltrating macrophages. The biodegradability and safety profile of the nanoprobes make them suitable for the systemic detection and localized treatment of cancer.
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Affiliation(s)
- Jiang Yang
- Center for Molecular Imaging and Nanotechnology (CMINT), Memorial Sloan Kettering Cancer Center, New York, NY, USA
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China
| | - Tai Wang
- Chemical Biology Program, Sloan Kettering Institute, New York, NY, USA
| | - Lina Zhao
- CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, China
| | | | - Suhasini Joshi
- Chemical Biology Program, Sloan Kettering Institute, New York, NY, USA
| | - Chrysafis Andreou
- Center for Molecular Imaging and Nanotechnology (CMINT), Memorial Sloan Kettering Cancer Center, New York, NY, USA
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Suchetan Pal
- Center for Molecular Imaging and Nanotechnology (CMINT), Memorial Sloan Kettering Cancer Center, New York, NY, USA
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Hsiao-Ting Hsu
- Center for Molecular Imaging and Nanotechnology (CMINT), Memorial Sloan Kettering Cancer Center, New York, NY, USA
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Hanwen Zhang
- Center for Molecular Imaging and Nanotechnology (CMINT), Memorial Sloan Kettering Cancer Center, New York, NY, USA
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Ivan J Cohen
- Center for Molecular Imaging and Nanotechnology (CMINT), Memorial Sloan Kettering Cancer Center, New York, NY, USA
- Louis V. Gerstner Jr Graduate School of Biomedical Sciences, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Ruimin Huang
- Center for Molecular Imaging and Nanotechnology (CMINT), Memorial Sloan Kettering Cancer Center, New York, NY, USA
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Ronald C Hendrickson
- Proteomics and Microchemistry Core Laboratory, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Matthew M Miele
- Proteomics and Microchemistry Core Laboratory, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Wenbo Pei
- Chemical Biology Program, Sloan Kettering Institute, New York, NY, USA
| | - Matthew B Brendel
- Molecular Cytology Core Laboratory, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - John H Healey
- Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Gabriela Chiosis
- Chemical Biology Program, Sloan Kettering Institute, New York, NY, USA
- Breast Cancer Service, Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Moritz F Kircher
- Center for Molecular Imaging and Nanotechnology (CMINT), Memorial Sloan Kettering Cancer Center, New York, NY, USA.
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
- Molecular Pharmacology Program, Sloan Kettering Institute, New York, NY, USA.
- Department of Radiology, Weill Cornell Medical College, New York, NY, USA.
- Department of Imaging, Dana-Farber Cancer Institute and Harvard Medical School, Boston, MA, USA.
- Department of Radiology, Brigham & Women's Hospital and Harvard Medical School, Boston, MA, USA.
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11
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Timms RT, Zhang Z, Rhee DY, Harper JW, Koren I, Elledge SJ. A glycine-specific N-degron pathway mediates the quality control of protein N-myristoylation. Science 2020; 365:365/6448/eaaw4912. [PMID: 31273098 DOI: 10.1126/science.aaw4912] [Citation(s) in RCA: 121] [Impact Index Per Article: 30.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2018] [Revised: 03/29/2019] [Accepted: 05/15/2019] [Indexed: 12/21/2022]
Abstract
The N-terminal residue influences protein stability through N-degron pathways. We used stability profiling of the human N-terminome to uncover multiple additional features of N-degron pathways. In addition to uncovering extended specificities of UBR E3 ligases, we characterized two related Cullin-RING E3 ligase complexes, Cul2ZYG11B and Cul2ZER1, that act redundantly to target N-terminal glycine. N-terminal glycine degrons are depleted at native N-termini but strongly enriched at caspase cleavage sites, suggesting roles for the substrate adaptors ZYG11B and ZER1 in protein degradation during apoptosis. Furthermore, ZYG11B and ZER1 were found to participate in the quality control of N-myristoylated proteins, in which N-terminal glycine degrons are conditionally exposed after a failure of N-myristoylation. Thus, an additional N-degron pathway specific for glycine regulates the stability of metazoan proteomes.
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Affiliation(s)
- Richard T Timms
- Division of Genetics, Department of Medicine, Howard Hughes Medical Institute, Brigham and Women's Hospital, Boston, MA 02115, USA.,Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Zhiqian Zhang
- Division of Genetics, Department of Medicine, Howard Hughes Medical Institute, Brigham and Women's Hospital, Boston, MA 02115, USA.,Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - David Y Rhee
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - J Wade Harper
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Itay Koren
- Division of Genetics, Department of Medicine, Howard Hughes Medical Institute, Brigham and Women's Hospital, Boston, MA 02115, USA. .,Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Stephen J Elledge
- Division of Genetics, Department of Medicine, Howard Hughes Medical Institute, Brigham and Women's Hospital, Boston, MA 02115, USA. .,Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
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12
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Cho SO, Lim JW, Kim H. Oxidative stress induces apoptosis via calpain- and caspase-3-mediated cleavage of ATM in pancreatic acinar cells. Free Radic Res 2019; 54:799-809. [PMID: 31401888 DOI: 10.1080/10715762.2019.1655145] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Oxidative stress-induced DNA cleavage and apoptosis in pancreatic acinar cells has been implicated in the pathogenesis of acute pancreatitis. Thus, an efficient DNA repair process is key to prevention of apoptotic pancreatic acinar cell death. Ataxia telangiectasia mutated (ATM), a sensor of DNA breaks, functions by recruiting DNA repair proteins to initiate the DNA repair process. In the present study, we investigated whether H2O2 produced by the action of glucose oxidase on α-D-glucose (G/GO) induces apoptosis in pancreatic acinar AR42J cells through an alteration of the level of ATM. As a result, G/GO induced apoptosis by promoting a loss of cell viability, increase in Bax, decrease in Bcl-2, cleavage of poly (ADP-ribose) polymerase (PARP) and fragmentation of DNA. In addition, ATM cleavage along with elevated levels of calpain and caspase-3 activity was induced by G/GO. By using ATM siRNA, we demonstrated that reduction in ATM levels enhanced G/GO-induced apoptosis. Moreover, inhibition of calpain activity by calpeptin or calpastatin, or by inhibition of caspase-3 with z-DEVD, suppressed G/GO-induced apoptosis and ATM cleavage. Collectively, these findings suggest that proteolysis of ATM is the underlying mechanism of apoptosis of pancreatic acinar cells caused by exposure to oxidative stress.
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Affiliation(s)
- Soon Ok Cho
- Department of Pharmacology, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Joo Weon Lim
- Department of Food and Nutrition, BK 21 Plus Project, College of Human Ecology, Yonsei University, Seoul, Republic of Korea
| | - Hyeyoung Kim
- Department of Food and Nutrition, BK 21 Plus Project, College of Human Ecology, Yonsei University, Seoul, Republic of Korea
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13
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Khan C, Muliyil S, Rao BJ. Genome Damage Sensing Leads to Tissue Homeostasis in Drosophila. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2019; 345:173-224. [PMID: 30904193 DOI: 10.1016/bs.ircmb.2018.12.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
DNA repair is a critical cellular process required for the maintenance of genomic integrity. It is now well appreciated that cells employ several DNA repair pathways to take care of distinct types of DNA damage. It is also well known that a cascade of signals namely DNA damage response or DDR is activated in response to DNA damage which comprise cellular responses, such as cell cycle arrest, DNA repair and cell death, if the damage is irreparable. There is also emerging literature suggesting a cross-talk between DNA damage signaling and several signaling networks within a cell. Moreover, cell death players themselves are also well known to engage in processes outside their canonical function of apoptosis. This chapter attempts to build a link between DNA damage, DDR and signaling from the studies mainly conducted in mammals and Drosophila model systems, with a special emphasis on their relevance in overall tissue homeostasis and development.
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Affiliation(s)
- Chaitali Khan
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, India
| | - Sonia Muliyil
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, India
| | - B J Rao
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, India.
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14
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Hoey C, Ray J, Jeon J, Huang X, Taeb S, Ylanko J, Andrews DW, Boutros PC, Liu SK. miRNA-106a and prostate cancer radioresistance: a novel role for LITAF in ATM regulation. Mol Oncol 2018; 12:1324-1341. [PMID: 29845714 PMCID: PMC6068351 DOI: 10.1002/1878-0261.12328] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Revised: 04/30/2018] [Accepted: 05/01/2018] [Indexed: 01/09/2023] Open
Abstract
Recurrence of high-grade prostate cancer after radiotherapy is a significant clinical problem, resulting in increased morbidity and reduced patient survival. The molecular mechanisms of radiation resistance are being elucidated through the study of microRNA (miR) that negatively regulate gene expression. We performed bioinformatics analyses of The Cancer Genome Atlas (TCGA) dataset to evaluate the association between miR-106a and its putative target lipopolysaccharide-induced TNF-α factor (LITAF) in prostate cancer. We characterized the function of miR-106a through in vitro and in vivo experiments and employed transcriptomic analysis, western blotting, and 3'UTR luciferase assays to establish LITAF as a bona fide target of miR-106a. Using our well-characterized radiation-resistant cell lines, we identified that miR-106a was overexpressed in radiation-resistant cells compared to parental cells. In the TCGA, miR-106a was significantly elevated in high-grade human prostate tumors relative to intermediate- and low-grade specimens. An inverse correlation was seen with its target, LITAF. Furthermore, high miR-106a and low LITAF expression predict for biochemical recurrence at 5 years after radical prostatectomy. miR-106a overexpression conferred radioresistance by increasing proliferation and reducing senescence, and this was phenocopied by knockdown of LITAF. For the first time, we describe a role for miRNA in upregulating ATM expression. LITAF, not previously attributed to radiation response, mediates this interaction. This route of cancer radioresistance can be overcome using the specific ATM kinase inhibitor, KU-55933. Our research provides the first report of miR-106a and LITAF in prostate cancer radiation resistance and high-grade disease, and presents a viable therapeutic strategy that may ultimately improve patient outcomes.
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Affiliation(s)
- Christianne Hoey
- Biological SciencesSunnybrook Research InstituteSunnybrook Health Sciences CentreTorontoCanada
- Department of Medical BiophysicsUniversity of TorontoCanada
| | - Jessica Ray
- Biological SciencesSunnybrook Research InstituteSunnybrook Health Sciences CentreTorontoCanada
- Department of Medical BiophysicsUniversity of TorontoCanada
| | - Jouhyun Jeon
- Ontario Institute for Cancer ResearchUniversity Health NetworkTorontoCanada
| | - Xiaoyong Huang
- Biological SciencesSunnybrook Research InstituteSunnybrook Health Sciences CentreTorontoCanada
| | - Samira Taeb
- Biological SciencesSunnybrook Research InstituteSunnybrook Health Sciences CentreTorontoCanada
| | - Jarkko Ylanko
- Biological SciencesSunnybrook Research InstituteSunnybrook Health Sciences CentreTorontoCanada
| | - David W. Andrews
- Biological SciencesSunnybrook Research InstituteSunnybrook Health Sciences CentreTorontoCanada
- Department of Medical BiophysicsUniversity of TorontoCanada
| | - Paul C. Boutros
- Department of Medical BiophysicsUniversity of TorontoCanada
- Ontario Institute for Cancer ResearchUniversity Health NetworkTorontoCanada
- Department of Pharmacology and ToxicologyUniversity of TorontoCanada
| | - Stanley K. Liu
- Biological SciencesSunnybrook Research InstituteSunnybrook Health Sciences CentreTorontoCanada
- Department of Medical BiophysicsUniversity of TorontoCanada
- Department of Radiation OncologyUniversity of TorontoCanada
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15
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Tahara K, Takizawa M, Yamane A, Osaki Y, Ishizaki T, Mitsui T, Yokohama A, Saitoh T, Tsukamoto N, Matsumoto M, Murakami H, Nojima Y, Handa H. Overexpression of B-cell lymphoma 6 alters gene expression profile in a myeloma cell line and is associated with decreased DNA damage response. Cancer Sci 2017; 108:1556-1564. [PMID: 28544233 PMCID: PMC5543477 DOI: 10.1111/cas.13283] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Revised: 04/22/2017] [Accepted: 05/10/2017] [Indexed: 01/02/2023] Open
Abstract
B-cell lymphoma 6 (BCL6) attenuates DNA damage response (DDR) through gene repression and facilitates tolerance to genomic instability during immunoglobulin affinity maturation in germinal center (GC) B cells. Although BCL6 expression is repressed through normal differentiation of GC B cells into plasma cells, a recent study showed the ectopic expression of BCL6 in primary multiple myeloma (MM) cells. However, the functional roles of BCL6 in MM cells are largely unknown. Here, we report that overexpression of BCL6 in a MM cell line, KMS12PE, induced transcriptional repression of ataxia telangiectasia mutated (ATM), a DDR signaling kinase, which was associated with a reduction in γH2AX formation after DNA damage. In contrast, transcription of known targets of BCL6 in GC B cells was not affected, suggesting a cell type-specific function of BCL6. To further investigate the effects of BCL6 overexpression on the MM cell line, we undertook mRNA sequence analysis and found an upregulation in the genomic mutator activation-induced cytidine deaminase (AID) with alteration in the gene expression profile, which is suggestive of de-differentiation from plasma cells. Moreover, interleukin-6 exposure to KMS12PE led to upregulation of BCL6 and AID, downregulation of ATM, and attenuation of DDR, which were consistent with the effects of BCL6 overexpression in this MM cell line. Taken together, these results indicated that overexpression of BCL6 alters gene expression profile and confers decreased DDR in MM cells. This phenotypic change could be reproduced by interleukin-6 stimulation, suggesting an important role of external stimuli in inducing genomic instability, which is a hallmark of MM cells.
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Affiliation(s)
- Kenichi Tahara
- Department of Medicine and Clinical ScienceGunma University Graduate School of MedicineGunmaJapan
| | - Makiko Takizawa
- Department of Medicine and Clinical ScienceGunma University Graduate School of MedicineGunmaJapan
| | - Arito Yamane
- Department of Medicine and Clinical ScienceGunma University Graduate School of MedicineGunmaJapan
| | - Yohei Osaki
- Department of Medicine and Clinical ScienceGunma University Graduate School of MedicineGunmaJapan
| | - Takuma Ishizaki
- Department of Medicine and Clinical ScienceGunma University Graduate School of MedicineGunmaJapan
| | - Takeki Mitsui
- Department of Medicine and Clinical ScienceGunma University Graduate School of MedicineGunmaJapan
| | - Akihiko Yokohama
- Division of Blood Transfusion ServiceGunma University HospitalGunmaJapan
| | - Takayuki Saitoh
- Department of Laboratory SciencesGunma University Graduate School of Health SciencesGunmaJapan
| | | | - Morio Matsumoto
- Department of HematologyNational Hospital Organization Nishigunma National HospitalGunmaJapan
| | - Hirokazu Murakami
- Department of Laboratory SciencesGunma University Graduate School of Health SciencesGunmaJapan
| | - Yoshihisa Nojima
- Department of Medicine and Clinical ScienceGunma University Graduate School of MedicineGunmaJapan
| | - Hiroshi Handa
- Department of Medicine and Clinical ScienceGunma University Graduate School of MedicineGunmaJapan
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16
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Shen J, Kim HC, Wolfram J, Mu C, Zhang W, Liu H, Xie Y, Mai J, Zhang H, Li Z, Guevara M, Mao ZW, Shen H. A Liposome Encapsulated Ruthenium Polypyridine Complex as a Theranostic Platform for Triple-Negative Breast Cancer. NANO LETTERS 2017; 17:2913-2920. [PMID: 28418672 PMCID: PMC5484597 DOI: 10.1021/acs.nanolett.7b00132] [Citation(s) in RCA: 89] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Ruthenium coordination complexes have the potential to serve as novel theranostic agents for cancer. However, a major limitation in their clinical implementation is effective tumor accumulation. In this study, we have developed a liposome-based theranostic nanodelivery system for [Ru(phen)2dppz](ClO4)2 (Lipo-Ru). This ruthenium polypyridine complex emits a strong fluorescent signal when incorporated in the hydrophobic lipid bilayer of the delivery vehicle or in the DNA helix, enabling visualization of the therapeutic agent in tumor tissues. Incubation of MDA-MB-231 breast cancer cells with Lipo-Ru induced double-strand DNA breaks and triggers apoptosis. In a mouse model of triple-negative breast cancer, treatment with Lipo-Ru dramatically reduced tumor growth. Biodistribution studies of Lipo-Ru revealed that more than 20% of the injected dose accumulated in the tumor. These results suggest that Lipo-Ru could serve as a promising theranostic platform for cancer.
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Affiliation(s)
- Jianliang Shen
- Department of Nanomedicine, Houston Methodist Research Institute, Houston, TX 77030, United States
| | - Han-Cheon Kim
- Department of Nanomedicine, Houston Methodist Research Institute, Houston, TX 77030, United States
| | - Joy Wolfram
- Department of Nanomedicine, Houston Methodist Research Institute, Houston, TX 77030, United States
- Department of Transplantation, Mayo Clinic, Jacksonville, FL 3224, United States
| | - Chaofeng Mu
- Department of Nanomedicine, Houston Methodist Research Institute, Houston, TX 77030, United States
| | - Wei Zhang
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou, 510275, China
| | - Haoran Liu
- Department of Nanomedicine, Houston Methodist Research Institute, Houston, TX 77030, United States
| | - Yan Xie
- Department of Nanomedicine, Houston Methodist Research Institute, Houston, TX 77030, United States
- Research Center for Health and Nutrition, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, China
| | - Junhua Mai
- Department of Nanomedicine, Houston Methodist Research Institute, Houston, TX 77030, United States
| | - Hang Zhang
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou, 510275, China
| | - Zhi Li
- Department of Nanomedicine, Houston Methodist Research Institute, Houston, TX 77030, United States
| | - Maria Guevara
- Department of Nanomedicine, Houston Methodist Research Institute, Houston, TX 77030, United States
| | - Zong-Wan Mao
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou, 510275, China
| | - Haifa Shen
- Department of Nanomedicine, Houston Methodist Research Institute, Houston, TX 77030, United States
- Department of Cell and Developmental Biology, Weill Cornell Medicine, New York, NY 10065, United States
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17
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Khan C, Muliyil S, Ayyub C, Rao BJ. DNA damage signalling in D. melanogaster requires non-apoptotic function of initiator caspase Dronc. J Cell Sci 2017; 130:2984-2995. [DOI: 10.1242/jcs.200782] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Accepted: 07/24/2017] [Indexed: 01/31/2023] Open
Abstract
ϒH2Av response constitutes an important signalling event in DNA damage sensing ensuring effective repair by recruiting DNA repair machinery. In contrast, the occurrence of ϒH2Av response has also been reported in dying cells where it is shown to require activation of CAD (caspase activated DNase). Moreover, caspases are known to be required downstream of DNA damage for cell death execution. We show, for the first time, that initiator caspase Dronc, independent of executioner caspases, acts as an upstream regulator of DNA Damage Response (DDR) by facilitating ϒH2Av signalling perhaps involving non-apoptotic function. Such ϒH2Av response is mediated by ATM rather than ATR, suggesting that Dronc function is required upstream of ATM. In contrast, ϒH2Av appearance during cell death requires effector caspase and is associated with fragmented nuclei. Our study uncovers a novel function of Dronc in response to DNA damage aimed at promoting DDR via ϒH2Av signalling in intact nuclei. We propose that Dronc plays a dual role that can either initiate DDR or apoptosis depending upon the level and the required threshold of its activation in damaged cells.
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Affiliation(s)
- Chaitali Khan
- Department of Biological Sciences, Tata Institute of Fundamental Research, Colaba, Mumbai 400005, India
| | - Sonia Muliyil
- Current affiliation: Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK
| | - Champakali Ayyub
- Department of Biological Sciences, Tata Institute of Fundamental Research, Colaba, Mumbai 400005, India
| | - B. J. Rao
- Department of Biological Sciences, Tata Institute of Fundamental Research, Colaba, Mumbai 400005, India
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18
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Iuchi K, Yagura T. DNA binding activity of Ku during chemotherapeutic agent-induced early apoptosis. Exp Cell Res 2016; 342:135-44. [PMID: 26976509 DOI: 10.1016/j.yexcr.2016.03.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2015] [Revised: 03/08/2016] [Accepted: 03/09/2016] [Indexed: 01/09/2023]
Abstract
Ku protein is a heterodimer composed of two subunits, and is capable of both sequence-independent and sequence-specific DNA binding. The former mode of DNA binding plays a crucial role in DNA repair. The biological role of Ku protein during apoptosis remains unclear. Here, we show characterization of Ku protein during apoptosis. In order to study the DNA binding properties of Ku, we used two methods for the electrophoresis mobility shift assay (EMSA). One method, RI-EMSA, which is commonly used, employed radiolabeled DNA probes. The other method, WB-EMSA, employed unlabeled DNA followed by western blot and detection with anti-Ku antiserum. In this study, Ku-DNA probe binding activity was found to dramatically decrease upon etoposide treatment, when examined by the RI-EMSA method. In addition, pre-treatment with apoptotic cell extracts inhibited Ku-DNA probe binding activity in the non-treated cell extract. The inhibitory effect of the apoptotic cell extract was reduced by DNase I treatment. WB-EMSA showed that the Ku in the apoptotic cell extract bound to fragmented endogenous DNA. Interestingly, Ku in the apoptotic cell extract purified by the Resource Q column bound 15-bp DNA in both RI-EMSA and WB-EMSA, whereas Ku in unpurified apoptotic cell extracts did not bind additional DNA. These results suggest that Ku binds cleaved chromosomal DNA and/or nucleosomes in apoptotic cells. In conclusion, Ku is intact and retains DNA binding activity in early apoptotic cells.
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Affiliation(s)
- Katsuya Iuchi
- Department of Bioscience, Faculty of Science and Technology, Kwansei Gakuin University, 2-1 Gakuin, Sanda-shi, Hyogo-ken 669-1337, Japan.
| | - Tatsuo Yagura
- Department of Bioscience, Faculty of Science and Technology, Kwansei Gakuin University, 2-1 Gakuin, Sanda-shi, Hyogo-ken 669-1337, Japan
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19
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Prognostic Significance of Nuclear Phospho-ATM Expression in Melanoma. PLoS One 2015; 10:e0134678. [PMID: 26275218 PMCID: PMC4537129 DOI: 10.1371/journal.pone.0134678] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Accepted: 07/13/2015] [Indexed: 12/21/2022] Open
Abstract
UV radiation induced genomic instability is one of the leading causes for melanoma. Phosphorylation of Ataxia Telangiectasia Mutated (ATM) is one of the initial events that follow DNA damage. Phospho-ATM (p-ATM) plays a key role in the activation of DNA repair and several oncogenic pathways as well as in the maintenance of genomic integrity. The present study was therefore performed to understand the significance of p-ATM in melanoma progression and to correlate it with patient prognosis. Tissue microarray and immunohistochemical analysis were employed to study the expression of p-ATM in melanoma patients. A total of 366 melanoma patients (230 primary melanoma and 136 metastatic melanoma) were used for the study. Chi-square test, Kaplan-Meier, univariate and multivariate Cox regression analysis were used to elucidate the prognostic significance of p-ATM expression. Results revealed that both loss of, and gain in, p-ATM expression were associated with progression of melanoma from normal nevi to metastatic melanoma. Patients whose samples showed negative or strong p-ATM staining had significantly worse 5-year survival compared to patients who had weak to moderate expression. Loss of p-ATM expression was associated with relatively better 5-year survival, but the corresponding 10-year survival curve almost overlapped with that of strong p-ATM expression. p-ATM expression was found to be an independent prognostic factor for 5-year but not for 10-year patient survival. In conclusion our findings show that loss of p-ATM expression and gain-in p-ATM expression are indicators of worse melanoma patient survival.
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20
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Ichim G, Lopez J, Ahmed SU, Muthalagu N, Giampazolias E, Delgado ME, Haller M, Riley JS, Mason SM, Athineos D, Parsons MJ, van de Kooij B, Bouchier-Hayes L, Chalmers AJ, Rooswinkel RW, Oberst A, Blyth K, Rehm M, Murphy DJ, Tait SWG. Limited mitochondrial permeabilization causes DNA damage and genomic instability in the absence of cell death. Mol Cell 2015; 57:860-872. [PMID: 25702873 PMCID: PMC4352766 DOI: 10.1016/j.molcel.2015.01.018] [Citation(s) in RCA: 307] [Impact Index Per Article: 34.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Revised: 10/24/2014] [Accepted: 01/08/2015] [Indexed: 12/25/2022]
Abstract
During apoptosis, the mitochondrial outer membrane is permeabilized, leading to the release of cytochrome c that activates downstream caspases. Mitochondrial outer membrane permeabilization (MOMP) has historically been thought to occur synchronously and completely throughout a cell, leading to rapid caspase activation and apoptosis. Using a new imaging approach, we demonstrate that MOMP is not an all-or-nothing event. Rather, we find that a minority of mitochondria can undergo MOMP in a stress-regulated manner, a phenomenon we term “minority MOMP.” Crucially, minority MOMP leads to limited caspase activation, which is insufficient to trigger cell death. Instead, this caspase activity leads to DNA damage that, in turn, promotes genomic instability, cellular transformation, and tumorigenesis. Our data demonstrate that, in contrast to its well-established tumor suppressor function, apoptosis also has oncogenic potential that is regulated by the extent of MOMP. These findings have important implications for oncogenesis following either physiological or therapeutic engagement of apoptosis. MOMP can occur in a minority of mitochondria Minority MOMP triggers caspase activity but fails to kill cells Minority MOMP-induced caspase activity causes DNA damage and genomic instability Minority MOMP promotes cellular transformation and tumorigenesis
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Affiliation(s)
- Gabriel Ichim
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK; Institute of Cancer Sciences, University of Glasgow, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK
| | - Jonathan Lopez
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK; Institute of Cancer Sciences, University of Glasgow, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK
| | - Shafiq U Ahmed
- Institute of Cancer Sciences, University of Glasgow, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK
| | - Nathiya Muthalagu
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK; Institute of Cancer Sciences, University of Glasgow, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK
| | - Evangelos Giampazolias
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK; Institute of Cancer Sciences, University of Glasgow, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK
| | - M Eugenia Delgado
- Centre for Systems Medicine, Royal College of Surgeons in Ireland, Dublin 2, Ireland, Baylor College of Medicine, Houston, TX 77030, USA
| | - Martina Haller
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK; Institute of Cancer Sciences, University of Glasgow, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK
| | - Joel S Riley
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK; Institute of Cancer Sciences, University of Glasgow, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK
| | - Susan M Mason
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK
| | - Dimitris Athineos
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK
| | - Melissa J Parsons
- Center for Cell and Gene Therapy, Baylor College of Medicine, Houston, TX 77030, USA; Department of Pediatrics-Hematology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Bert van de Kooij
- Division of Immunology, The Netherlands Cancer Institute, Plesmanlaan 121, Amsterdam 1066 CX, the Netherlands
| | - Lisa Bouchier-Hayes
- Center for Cell and Gene Therapy, Baylor College of Medicine, Houston, TX 77030, USA; Department of Pediatrics-Hematology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Anthony J Chalmers
- Institute of Cancer Sciences, University of Glasgow, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK
| | - Rogier W Rooswinkel
- Division of Immunology, The Netherlands Cancer Institute, Plesmanlaan 121, Amsterdam 1066 CX, the Netherlands
| | - Andrew Oberst
- Department of Immunology, University of Washington, 750 Republican Street, Seattle, WA 98109, USA
| | - Karen Blyth
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK
| | - Markus Rehm
- Centre for Systems Medicine, Royal College of Surgeons in Ireland, Dublin 2, Ireland, Baylor College of Medicine, Houston, TX 77030, USA
| | - Daniel J Murphy
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK; Institute of Cancer Sciences, University of Glasgow, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK
| | - Stephen W G Tait
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK; Institute of Cancer Sciences, University of Glasgow, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK.
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21
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Cremona CA, Behrens A. ATM signalling and cancer. Oncogene 2014; 33:3351-60. [PMID: 23851492 DOI: 10.1038/onc.2013.275] [Citation(s) in RCA: 152] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2013] [Revised: 05/17/2013] [Accepted: 05/20/2013] [Indexed: 12/12/2022]
Abstract
ATM, the protein kinase mutated in the rare human disease ataxia telangiectasia (A-T), has been the focus of intense scrutiny over the past two decades. Initially this was because of the unusual radiosensitive phenotype of cells from A-T patients, and latterly because investigating ATM signalling has yielded valuable insights into the DNA damage response, redox signalling and cancer. With the recent explosion in genomic data, ATM alterations have been revealed both in the germline as a predisposing factor for cancer and as somatic changes in tumours themselves. Here we review these findings, as well as advances in the understanding of ATM signalling mechanisms in cancer and ATM inhibition as a strategy for cancer treatment.
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Affiliation(s)
- C A Cremona
- Mammalian Genetics Lab, Cancer Research UK London Research Institute, London, UK
| | - A Behrens
- Mammalian Genetics Lab, Cancer Research UK London Research Institute, London, UK
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22
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Okita N, Yoshimura M, Watanabe K, Minato S, Kudo Y, Higami Y, Tanuma SI. CHK1 cleavage in programmed cell death is intricately regulated by both caspase and non-caspase family proteases. Biochim Biophys Acta Gen Subj 2012; 1830:2204-13. [PMID: 23085068 DOI: 10.1016/j.bbagen.2012.10.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2012] [Revised: 09/18/2012] [Accepted: 10/10/2012] [Indexed: 02/08/2023]
Abstract
BACKGROUND CHK1 is an important effector kinase that regulates the cell cycle checkpoint. Previously, we showed that CHK1 is cleaved in a caspase (CASP)-dependent manner during DNA damage-induced programmed cell death (PCD) and have examined its physiological roles. METHODS AND RESULTS In this study, we investigated the behavior of CHK1 in PCD. Firstly, we found that CHK1 is cleaved at three sites in PCD, and all cleavages were inhibited by the co-treatment of a pan-CASP inhibitor or serine protease inhibitors. We also showed that CHK1 is cleaved by CASP3 and/or CASP7 recognizing at (296)SNLD(299) and (348)TCPD(351), and that the cleavage results in the enhancement of CHK1 kinase activity. Furthermore, as a result of the characterization of cleavage sites by site-directed mutagenesis and an analysis performed using deletion mutants, we identified (320)EPRT(323) as an additional cleavage recognition sequence. Considering the consensus sequence cleaved by CASP, it is likely that CHK1 is cleaved by non-CASP family protease(s) recognizing at (320)EPRT(323). Additionally, the cleavage catalyzed by the (320)EPRT(323) protease(s) markedly and specifically increased when U2OS cells synchronized into G1 phase were induced to PCD by cisplatin treatment. CONCLUSION CHK1 cleavage is directly and indirectly regulated by CASP and non-CASP family proteases including serine protease(s) and the "(320)EPRT(323) protease(s)." Furthermore, (320)EPRT(323) cleavage of CHK1 occurs efficiently in PCD which is induced at the G1 phase by DNA damage. GENERAL SIGNIFICANCE CASP and non-CASP family proteases intricately regulate cleavage for up-regulation of CHK1 kinase activity during PCD.
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Affiliation(s)
- Naoyuki Okita
- Department of Molecular Pathology and Metabolic Disease, Tokyo University of Science, Chiba, Japan.
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23
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Nowsheen S, Yang E. The intersection between DNA damage response and cell death pathways. Exp Oncol 2012; 34:243-254. [PMID: 23070009 PMCID: PMC3754840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Apoptosis is a finely regulated process that serves to determine the fate of cells in response to various stresses. One such stress is DNA damage, which not only can signal repair processes but is also intimately involved in regulating cell fate. In this review we examine the relationship between the DNA damage/repair response in cell survival and apoptosis following insults to the DNA. Elucidating these pathways and the crosstalk between them is of great importance, as they eventually contribute to the etiology of human disease such as cancer and may play key roles in determining therapeutic response. This article is part of a Special Issue entitled "Apoptosis: Four Decades Later".
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Affiliation(s)
- S. Nowsheen
- Departments of Radiation Oncology, Comprehensive Cancer Center, University of Alabama at Birmingham School of Medicine, Alabama, USA
| | - E.S. Yang
- Departments of Radiation Oncology, Comprehensive Cancer Center, University of Alabama at Birmingham School of Medicine, Alabama, USA
- Departments of Cell, Developmental, and Integrative Biology, Comprehensive Cancer Center, University of Alabama at Birmingham School of Medicine, Alabama, USA
- Departments of Pharmacology and Toxicology, Comprehensive Cancer Center, University of Alabama at Birmingham School of Medicine, Alabama, USA
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24
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Lei K, Zhu X, Xu R, Shao C, Xu T, Zhuang Y, Han M. Inner nuclear envelope proteins SUN1 and SUN2 play a prominent role in the DNA damage response. Curr Biol 2012; 22:1609-15. [PMID: 22863315 PMCID: PMC3466333 DOI: 10.1016/j.cub.2012.06.043] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2011] [Revised: 05/23/2012] [Accepted: 06/13/2012] [Indexed: 11/28/2022]
Abstract
The DNA damage response (DDR) and DNA repair are critical for maintaining genomic stability and evading many human diseases. Recent findings indicate that accumulation of SUN1, a nuclear envelope (NE) protein, is a significant pathogenic event in Emery-Dreifuss muscular dystrophy and Hutchinson-Gilford progeria syndrome, both caused by mutations in LMNA. However, roles of mammalian SUN proteins in mitotic cell division and genomic stability are unknown. Here we report that the inner NE proteins SUN1 and SUN2 may play a redundant role in DDR. Mouse embryonic fibroblasts from Sun1(-/-)Sun2(-/-) mice displayed premature proliferation arrest in S phase of cell cycle, increased apoptosis and DNA damage, and decreased perinuclear heterochromatin, indicating genome instability. Furthermore, activation of ATM and H2A.X, early events in DDR, were impaired in Sun1(-/-)Sun2(-/-) fibroblasts. A biochemical screen identified interactions between SUN1 and SUN2 and DNA-dependent protein kinase (DNAPK) complex that functions in DNA nonhomologous end joining repair and possibly in DDR. Knockdown of DNAPK reduced ATM activation in NIH 3T3 cells, consistent with a potential role of SUN1- and SUN2-DNAPK interaction during DDR. SUN1 and SUN2 could affect DDR by localizing certain nuclear factors to the NE or by mediating communication between nuclear and cytoplasmic events.
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Affiliation(s)
- Kai Lei
- Institute of Developmental Biology and Molecular Medicine, School of Life Science, Fudan University, Shanghai 200433, China
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25
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Jacquemin V, Rieunier G, Jacob S, Bellanger D, d'Enghien CD, Laugé A, Stoppa-Lyonnet D, Stern MH. Underexpression and abnormal localization of ATM products in ataxia telangiectasia patients bearing ATM missense mutations. Eur J Hum Genet 2011; 20:305-12. [PMID: 22071889 DOI: 10.1038/ejhg.2011.196] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Ataxia telangiectasia (A-T) is a rare autosomal recessive disorder characterized by progressive cerebellar ataxia, oculocutaneous telangiectasia, immune defects and predisposition to malignancies. A-T is caused by biallelic inactivation of the ATM gene, in most cases by frameshift or nonsense mutations. More rarely, ATM missense mutations with unknown consequences on ATM function are found, making definitive diagnosis more challenging. In this study, a series of 15 missense mutations, including 11 not previously reported, were identified in 16 patients with clinical diagnosis of A-T belonging to 14 families and 1 patient with atypical clinical features. ATM function was evaluated in patient lymphoblastoid cell lines by measuring H2AX and KAP1 phosphorylation in response to ionizing radiation, confirming the A-T diagnosis for 16 cases. In accordance with previous studies, we showed that missense mutations associated with A-T often lead to ATM protein underexpression (15 out of 16 cases). In addition, we demonstrated that most missense mutations lead to an abnormal cytoplasmic localization of ATM, correlated with its decreased expression. This new finding highlights ATM mislocalization as a new mechanism of ATM dysfunction, which may lead to therapeutic strategies for missense mutation associated A-T.
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26
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Loughery JE, Dunne PD, O'Neill KM, Meehan RR, McDaid JR, Walsh CP. DNMT1 deficiency triggers mismatch repair defects in human cells through depletion of repair protein levels in a process involving the DNA damage response. Hum Mol Genet 2011; 20:3241-55. [DOI: 10.1093/hmg/ddr236] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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27
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Targeting the DNA double strand break repair machinery in prostate cancer. PLoS One 2011; 6:e20311. [PMID: 21629734 PMCID: PMC3100351 DOI: 10.1371/journal.pone.0020311] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2011] [Accepted: 04/28/2011] [Indexed: 12/31/2022] Open
Abstract
Regardless of the achievable remissions with first line hormone therapy in patients with prostate cancer (CaP), the disease escapes the hormone dependent stage to a more aggressive status where chemotherapy is the only effective treatment and no treatment is curative. This makes it very important to identify new targets that can improve the outcome of treatment. ATM and DNA-PK are the two kinases responsible for signalling and repairing double strand breaks (DSB). Thus, both kinases are pertinent targets in CaP treatment to enhance the activity of the numerous DNA DSB inducing agents used in CaP treatment such as ionizing radiation (IR). Colony formation assay was used to assess the sensitivity of hormone dependent, p53 wt (LNCaP) and hormone independent p53 mutant (PC3) CaP cell lines to the cytotoxic effect of IR and Doxorubicin in the presence or absence of Ku55933 and NU7441 which are small molecule inhibitors of ATM and DNA-PK, respectively. Flow cytometry based methods were used to assess the effect of the two inhibitors on cell cycle, apoptosis and H2AX foci formation. Neutral comet assay was used to assess the induction of DNA DSBs. Ku55933 or NU7441 alone increased the sensitivity of CaP cell lines to the DNA damaging agents, however combining both inhibitors together resulted in further enhancement of sensitivity. The cell cycle profile of both cell lines was altered with increased cell death, DNA DSBs and H2AX foci formation. This study justifies further evaluation of the ATM and DNA-PK inhibitors for clinical application in CaP patients. Additionally, the augmented effect resulting from combining both inhibitors may have a significant implication for the treatment of CaP patients who have a defect in one of the two DSB repair pathways.
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28
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Singh PK, Kumar R, Sharma A, Arora R, Chawla R, Jain SK, Tripathi RP, Sharma RK. Role of Apoptotic Proteins in REC-2006 Mediated Radiation Protection in Hepatoma Cell Lines. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2011; 2011:758326. [PMID: 21799693 PMCID: PMC3137560 DOI: 10.1093/ecam/neq059] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/20/2009] [Accepted: 04/09/2010] [Indexed: 11/12/2022]
Abstract
The present study was carried out to evaluate the role of apoptotic proteins in REC-2006-mediated radiation protection in hepatoma cell lines. REC-2006 treatment 2 h before irradiation strongly inhibited the cleavage of ATM and PARP-1 in HepG2 cells. The expression of nuclear apoptosis inducing factor (AIF) was found to be more inhibited (~17%) in HepG2 cells in REC-2006 + radiation-treated group. More inhibition (~33%) of cytochrome c was observed in HepG2 cells upon REC-2006 treatment 2 h prior irradiation. Similarly, significantly more (P<.05) inhibition of Apaf-1, caspase-9 and caspase-3 was observed in REC-2006 + radition-treated group in HepG2 cells. REC-2006 treatment restored the expression of ICAD in HepG2 cells; however, no restoration was observed in Hep3B cells. Lower nuclear to cytoplasmic CAD ratio was observed in HepG2 cells (~0.6) as compared with Hep3B cells (~1.2) in REC-2006 + radiation-treated group. In conclusion, REC-2006 rendered higher protection in HepG2 cells by inhibiting the expression and translocation of AIF, inhibiting the cleavage of ATM and PARP-1, restoring the expression of ICAD, inhibiting the release of cytochrome c and thus modulating the expression of Apaf-1 caspase-9 and activity of caspase-3.
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Solier S, Pommier Y. MDC1 cleavage by caspase-3: a novel mechanism for inactivating the DNA damage response during apoptosis. Cancer Res 2010; 71:906-13. [PMID: 21148072 DOI: 10.1158/0008-5472.can-10-3297] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Recently, we identified the "apoptotic ring," containing phosphorylated histone H2AX (γ-H2AX), as an early chromatin modification during apoptosis. Because γ-H2AX initiates the DNA damage response (DDR), we tested whether the apoptotic H2AX response leads to the full recruitment of the DDR factors that normally coordinate DNA repair and cell-cycle checkpoints. We show that the apoptotic H2AX response does not recruit the DDR factors because MDC1 (mediator of DNA damage checkpoint protein 1), which normally binds to γ-H2AX in response to DNA damage and amplifies the DDR, is cleaved by caspase-3. This cleavage separates the BRCT and FHA domains of MDC1 and constitutes a novel mechanism for the inactivation of DNA repair in apoptotic cells. Also, we show that downregulation of MDC1 increases the apoptotic response to TRAIL. Together, these results implicate MDC1 in the cellular apoptotic response.
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Affiliation(s)
- Stéphanie Solier
- Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland 20892, USA
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30
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Wen W, Zhu F, Zhang J, Keum YS, Zykova T, Yao K, Peng C, Zheng D, Cho YY, Ma WY, Bode AM, Dong Z. MST1 promotes apoptosis through phosphorylation of histone H2AX. J Biol Chem 2010; 285:39108-16. [PMID: 20921231 DOI: 10.1074/jbc.m110.151753] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
MST1 (mammalian STE20-like kinase 1) is a serine/threonine kinase that is cleaved and activated by caspases during apoptosis. Overexpression of MST1 induces apoptotic morphological changes such as chromatin condensation, but the mechanism is not clear. Here we show that MST1 induces apoptotic chromatin condensation through its phosphorylation of histone H2AX at Ser-139. During etoposide-induced apoptosis in Jurkat cells, the cleavage of MST1 directly corresponded with strong H2AX phosphorylation. In vitro kinase assay results showed that MST1 strongly phosphorylates histone H2AX. Western blot and kinase assay results with a mutant S139A H2AX confirmed that MST1 phosphorylates H2AX at Ser-139. Direct binding of MST1 and H2AX can be detected when co-expressed in HEK293 cells and was also confirmed by an endogenous immunoprecipitation study. When overexpressed in HeLa cells, both the MST1 full-length protein and the MST1 kinase domain (MST1-NT), but not the kinase-negative mutant (MST1-NT-KN), could induce obvious endogenous histone H2AX phosphorylation. The caspase-3 inhibitor benzyloxycarbonyl-DEVD-fluoromethyl ketone (Z-DEVD-fmk) attenuates phosphorylation of H2AX by MST1 but cannot inhibit MST1-NT-induced histone H2AX phosphorylation, indicating that cleaved MST1 is responsible for H2AX phosphorylation during apoptosis. Histone H2AX phosphorylation and DNA fragmentation were suppressed in MST1 knockdown Jurkat cells after etoposide treatment. Taken together, our data indicated that H2AX is a substrate of MST1, which functions to induce apoptotic chromatin condensation and DNA fragmentation.
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Affiliation(s)
- Weihong Wen
- Hormel Institute, University of Minnesota, Austin, Minnesota 55912, USA
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31
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Yuan J, Adamski R, Chen J. Focus on histone variant H2AX: to be or not to be. FEBS Lett 2010; 584:3717-24. [PMID: 20493860 DOI: 10.1016/j.febslet.2010.05.021] [Citation(s) in RCA: 190] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2010] [Revised: 05/04/2010] [Accepted: 05/11/2010] [Indexed: 12/16/2022]
Abstract
Phosphorylation of histone variant H2AX at serine 139, named gammaH2AX, has been widely used as a sensitive marker for DNA double-strand breaks (DSBs). gammaH2AX is required for the accumulation of many DNA damage response (DDR) proteins at DSBs. Thus it is believed to be the principal signaling protein involved in DDR and to play an important role in DNA repair. However, only mild defects in DNA damage signaling and DNA repair were observed in H2AX-deficient cells and animals. Such findings prompted us and others to explore H2AX-independent mechanisms in DNA damage response. Here, we will review recent advances in our understanding of H2AX-dependent and independent DNA damage signaling and repair pathways in mammalian cells.
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Affiliation(s)
- Jingsong Yuan
- Department of Experimental Radiation Oncology, The University of Texas M.D. Anderson Cancer Center, Houston, TX 77030, USA
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32
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Karasic TB, Hei TK, Ivanov VN. Disruption of IGF-1R signaling increases TRAIL-induced apoptosis: a new potential therapy for the treatment of melanoma. Exp Cell Res 2010; 316:1994-2007. [PMID: 20417200 DOI: 10.1016/j.yexcr.2010.04.014] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2010] [Revised: 04/01/2010] [Accepted: 04/15/2010] [Indexed: 01/07/2023]
Abstract
Resistance of cancer cells to apoptosis is dependent on a balance of multiple genetic and epigenetic mechanisms, which up-regulate efficacy of the surviving growth factor-receptor signaling pathways and suppress death-receptor signaling pathways. The Insulin-like Growth Factor-1 Receptor (IGF-1R) signaling pathway is highly active in metastatic melanoma cells by mediating downstream activation of PI3K-AKT and MAPK pathways and controlling general cell survival and proliferation. In the present study, we used human melanoma lines with established genotypes that represented different phases of cancer development: radial-growth-phase WM35, vertical-growth-phase WM793, metastatic LU1205 and WM9 [1]. All these lines have normal NRAS. WM35, WM793, LU1205 and WM9 cells have mutated BRAF (V600E). WM35 and WM9 cells express normal PTEN, while in WM793 cells PTEN expression is down-regulated; finally, in LU1205 cells PTEN is inactivated by mutation. Cyclolignan picropodophyllin (PPP), a specific inhibitor of IGF-1R kinase activity, strongly down-regulated the basal levels of AKT activity in WM9 and in WM793 cells, modestly does so in LU1205, but has no effect on AKT activity in the early stage WM35 cells that are deficient in IGF-1R. In addition, PPP partially down-regulated the basal levels of active ERK1/2 in all lines used, highlighting the role of an alternative, non-BRAF pathway in MAPK activation. The final result of PPP treatment was an induction of apoptosis in WM793, WM9 and LU1205 melanoma cells. On the other hand, dose-dependent inhibition of IGF-1R kinase activity by PPP at a relatively narrow dose range (near 500 nM) has different effects on melanoma cells versus normal cells, inducing apoptosis in cancer cells and G2/M arrest of fibroblasts. To further enhance the pro-apoptotic effects of PPP on melanoma cells, we used a combined treatment of TNF-Related Apoptosis-Inducing Ligand (TRAIL) and PPP. This combination substantially increased death by apoptosis for WM793 and WM9 cells, but did so only modestly for LU1205 cells with very high basal activity of AKT. The ultimate goal of this direction of research is the discovery of a new treatment method for highly resistant human metastatic melanomas. Our findings provide the rationale for further preclinical evaluation of this novel treatment.
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Affiliation(s)
- Thomas B Karasic
- Center for Radiological Research, Department of Radiation Oncology, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
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33
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Abstract
Kinases and proteases are responsible for two fundamental regulatory mechanisms--phosphorylation and proteolysis--that orchestrate the rhythms of life and death in all organisms. Recent studies have highlighted the elaborate interplay between both post-translational regulatory systems. Many intracellular or pericellular proteases are regulated by phosphorylation, whereas multiple kinases are activated or inactivated by proteolytic cleavage. The functional consequences of this regulatory crosstalk are especially relevant in the different stages of cancer progression. What are the clinical implications derived from the fertile dialogue between kinases and proteases in cancer?
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Affiliation(s)
- Carlos López-Otín
- Departamento de Bioquímica y Biología Molecular, Facultad de Medicina, Instituto Universitario de Oncología, Universidad de Oviedo, 33006 Oviedo, Spain.
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Powell MD, Manandhar G, Spate L, Sutovsky M, Zimmerman S, Sachdev SC, Hannink M, Prather RS, Sutovsky P. Discovery of putative oocyte quality markers by comparative ExacTag proteomics. Proteomics Clin Appl 2010; 4:337-51. [PMID: 21137054 DOI: 10.1002/prca.200900024] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2009] [Revised: 10/01/2009] [Accepted: 11/03/2009] [Indexed: 12/28/2022]
Abstract
PURPOSE Identification of the biomarkers of oocyte quality, and developmental and reprogramming potential is of importance to assisted reproductive technology in humans and animals. EXPERIMENTAL DESIGN PerkinElmer ExacTag™ Kit was used to label differentially proteins in pig oocyte extracts (oocyte proteome) and pig oocyte-conditioned in vitro maturation media (oocyte secretome) obtained with high- and low-quality oocytes. RESULTS We identified 16 major proteins in the oocyte proteome that were expressed differentially in high- versus low-quality oocytes. More abundant proteins in the high-quality oocyte proteome included kelch-like ECH-associated protein 1 (an adaptor for ubiquitin-ligase CUL3), nuclear export factor CRM1 and ataxia-telangiectasia mutated protein kinase. Dystrophin (DMD) was more abundant in low-quality oocytes. In the secretome, we identified 110 proteins, including DMD and cystic fibrosis transmembrane conductance regulator, two proteins implicated in muscular dystrophy and cystic fibrosis, respectively. Monoubiquitin was identified in the low-quality-oocyte secretome. CONCLUSIONS AND CLINICAL IMPLICATIONS A direct, quantitative proteomic analysis of small oocyte protein samples can identify potential markers of oocyte quality without the need for a large amount of total protein. This approach will be applied to discovery of non-invasive biomarkers of oocyte quality in assisted human reproduction and in large animal embryo transfer programs.
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Almeida S, Cunha-Oliveira T, Laço M, Oliveira CR, Rego AC. Dysregulation of CREB activation and histone acetylation in 3-nitropropionic acid-treated cortical neurons: prevention by BDNF and NGF. Neurotox Res 2009; 17:399-405. [PMID: 19779956 DOI: 10.1007/s12640-009-9116-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2008] [Revised: 08/28/2009] [Accepted: 09/08/2009] [Indexed: 11/30/2022]
Abstract
3-Nitropropionic acid (3-NP), an inhibitor of mitochondrial complex II, leads to metabolic impairment and neurodegeneration. In this study, we investigated the roles of brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) in the dysregulation of transcription factors and histone modifying enzymes induced by 3-NP in primary cortical neurons. BDNF prevented the 3-NP-induced decrease in cAMP response-element binding protein (CREB) phosphorylation and CREB-binding protein levels. Both NGF and BDNF counteracted the increase in the levels of histone H3 and H4 acetylations and reduced histone deacetylase (HDAC) activity induced by 3-NP. BDNF further led to hyperphosphorylation of HDAC2. Our results support an important role for neurotrophins, particularly BDNF, in preventing detrimental changes in transcription factors and histone acetylation states in cortical neurons that have been subjected to selective mitochondrial inhibition.
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Affiliation(s)
- Sandra Almeida
- Center for Neuroscience and Cell Biology, Faculty of Medicine, Institute of Biochemistry, University of Coimbra, 3004-504 Coimbra, Portugal
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36
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Jang SH, Lim JW, Kim H. Mechanism of beta-carotene-induced apoptosis of gastric cancer cells: involvement of ataxia-telangiectasia-mutated. Ann N Y Acad Sci 2009; 1171:156-62. [PMID: 19723050 DOI: 10.1111/j.1749-6632.2009.04711.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Beta-carotene acts as an antioxidant or a pro-oxidant depending on the concentrations that cells are treated with. Oxidative DNA damage is related to apoptosis of various cells. Ataxia-telangiectasia-mutated (ATM), a sensor for DNA-damaging agents, activates a variety of effectors in multiple signaling pathways, such as DNA repair and apoptosis. In the present study, we investigated whether a high concentration of beta-carotene induces apoptosis of gastric adenocarcinoma (AGS) cells and whether ATM is involved in beta-carotene-induced apoptosis of AGS cells. We found that beta-carotene (100 micromol/L) induced apoptosis (determined by cell viability), DNA fragmentation, and the protein levels of p53 and Bcl-2 in AGS cells. ATM levels in the nucleus decreased from beta-carotene in AGS cells. beta-Carotene-induced alterations, including an increase in DNA fragmentation and p53 levels and a decrease in nuclear ATM and cellular Bcl-2 levels, were inhibited in the cells transfected with full-length ATM cDNA compared to wild-type cells or the cells transfected with control vector plasmid control DNA vector (pcDNA). In conclusion, beta-carotene induces apoptosis by increasing apoptotic protein p53 and decreasing anti-apoptotic Bcl-2 as well as nuclear ATM in AGS cells. Nuclear loss of ATM may be the underlying mechanism of beta-carotene-induced apoptosis of gastric cancer cells.
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Affiliation(s)
- Sung Hee Jang
- Department of Food and Nutrition, Brain Korea 21 Project, College of Human Ecology, Yonsei University, Seoul, Korea
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37
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Bolderson E, Richard DJ, Edelmann W, Khanna KK. Involvement of Exo1b in DNA damage-induced apoptosis. Nucleic Acids Res 2009; 37:3452-63. [PMID: 19339515 PMCID: PMC2691832 DOI: 10.1093/nar/gkp194] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Apoptosis is essential for the maintenance of inherited genomic integrity. During DNA damage-induced apoptosis, mechanisms of cell survival, such as DNA repair are inactivated to allow cell death to proceed. Here, we describe a role for the mammalian DNA repair enzyme Exonuclease 1 (Exo1) in DNA damage-induced apoptosis. Depletion of Exo1 in human fibroblasts, or mouse embryonic fibroblasts led to a delay in DNA damage-induced apoptosis. Furthermore, we show that Exo1 acts upstream of caspase-3, DNA fragmentation and cytochrome c release. In addition, induction of apoptosis with DNA-damaging agents led to cleavage of both isoforms of Exo1. The cleavage of Exo1 was mapped to Asp514, and shown to be mediated by caspase-3. Expression of a caspase-3 cleavage site mutant form of Exo1, Asp514Ala, prevented formation of the previously observed fragment without any affect on the onset of apoptosis. We conclude that Exo1 has a role in the timely induction of apoptosis and that it is subsequently cleaved and degraded during apoptosis, potentially inhibiting DNA damage repair.
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Affiliation(s)
- Emma Bolderson
- Signal Transduction Laboratory, Queensland Institute of Medical Research, Brisbane, Queensland 4006, Australia
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38
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Cell-cycle control in the face of damage--a matter of life or death. Trends Cell Biol 2009; 19:89-98. [PMID: 19168356 DOI: 10.1016/j.tcb.2008.12.003] [Citation(s) in RCA: 113] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2008] [Revised: 12/09/2008] [Accepted: 12/09/2008] [Indexed: 12/31/2022]
Abstract
Cells respond to DNA damage or defects in the mitotic spindle by activating checkpoints that arrest the cell cycle. Alternatively, damaged cells can undergo cell death by the process of apoptosis. The correct balance between these pathways is important for the maintenance of genomic integrity while preventing unnecessary cell death. Although the molecular mechanisms of the cell cycle and apoptosis have been elucidated, the links between them have not been clear. Recent work, however, indicates that common components directly link the regulation of apoptosis with cell-cycle checkpoints operating during interphase, whereas in mitosis, the control of apoptosis is directly coupled to the cell-cycle machinery. These findings shed new light on how the balance between cell-cycle progression and cell death is controlled.
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Brown ET, Robinson-Benion C, Holt JT. Radiation enhances caspase 3 cleavage of Rad51 in BRCA2-defective cells. Radiat Res 2008; 169:595-601. [PMID: 18439040 DOI: 10.1667/rr1129.1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2007] [Accepted: 01/11/2008] [Indexed: 11/03/2022]
Abstract
After DNA damage, caspases cleave and activate proteins involved in cell death by apoptosis but also cleave and inactivate proteins implicated in DNA repair. Here we report a rapid onset of Rad51 cleavage by caspase 3 in BRCA2-defective mouse and human cells. This rapid cleavage was reduced markedly by transfer of full-length human BRCA2 into BRCA2-defective mouse or human cells, which also blocked the association of caspase 3 and Rad51 proteins. Overall caspase 3 activity was increased in BRCA2-defective cells, but the time course was much slower than that for Rad51 cleavage. We further showed that caspase 3 cleavage of Rad51 resulted in a functional decrease in Rad51 strand exchange activity and that inhibition of caspase 3 activity increased Rad51 protein levels and Rad51 foci. These findings indicate that BRCA2 inhibits Rad51 cleavage and subsequent apoptosis.
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Affiliation(s)
- Erika T Brown
- Department of Pathology, University of Colorado Health Sciences Center, Aurora, Colorado 80010-7163, USA
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40
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Matskevich AA, Moelling K. Dicer is involved in protection against influenza A virus infection. J Gen Virol 2007; 88:2627-2635. [PMID: 17872512 DOI: 10.1099/vir.0.83103-0] [Citation(s) in RCA: 93] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
In mammals the interferon (IFN) system is a central innate antiviral defence mechanism, while the involvement of RNA interference (RNAi) in antiviral response against RNA viruses is uncertain. Here, we tested whether RNAi is involved in the antiviral response in mammalian cells. To investigate the role of RNAi in influenza A virus-infected cells in the absence of IFN, we used Vero cells that lack IFN-alpha and IFN-beta genes. Our results demonstrate that knockdown of a key RNAi component, Dicer, led to a modest increase of virus production and accelerated apoptosis of influenza A virus-infected cells. These effects were much weaker in the presence of IFN. The results also show that in both Vero cells and the IFN-producing alveolar epithelial A549 cell line influenza A virus targets Dicer at mRNA and protein levels. Thus, RNAi is involved in antiviral response, and Dicer is important for protection against influenza A virus infection.
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Affiliation(s)
- Alexey A Matskevich
- Institute of Medical Virology, University of Zurich, Gloriastrasse 30/32, CH-8006 Zurich, Switzerland
| | - Karin Moelling
- Institute of Medical Virology, University of Zurich, Gloriastrasse 30/32, CH-8006 Zurich, Switzerland
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41
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ATM kinase activity modulates Fas sensitivity through the regulation of FLIP in lymphoid cells. Blood 2007; 111:829-37. [PMID: 17932249 DOI: 10.1182/blood-2007-04-085399] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Ataxia telangiectasia (A-T) is a rare cancer-predisposing genetic disease, caused by the lack of functional ATM kinase, a major actor of the double strand brakes (DSB) DNA-damage response. A-T patients show a broad and diverse phenotype, which includes an increased rate of lymphoma and leukemia development. Fas-induced apoptosis plays a fundamental role in the homeostasis of the immune system and its defects have been associated with autoimmunity and lymphoma development. We therefore investigated the role of ATM kinase in Fas-induced apoptosis. Using A-T lymphoid cells, we could show that ATM deficiency causes resistance to Fas-induced apoptosis. A-T cells up-regulate FLIP protein levels, a well-known inhibitor of Fas-induced apoptosis. Reconstitution of ATM kinase activity was sufficient to decrease FLIP levels and to restore Fas sensitivity. Conversely, genetic and pharmacologic ATM kinase inactivation resulted in FLIP protein up-regulation and Fas resistance. Both ATM and FLIP are aberrantly regulated in Hodgkin lymphoma. Importantly, we found that reconstitution of ATM kinase activity decreases FLIP protein levels and restores Fas sensitivity in Hodgkin lymphoma-derived cells. Overall, these data identify a novel molecular mechanism through which ATM kinase may regulate the immune system homeostasis and impair lymphoma development.
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42
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Chattopadhyay S, Bielinsky AK. Human Mcm10 regulates the catalytic subunit of DNA polymerase-alpha and prevents DNA damage during replication. Mol Biol Cell 2007; 18:4085-95. [PMID: 17699597 PMCID: PMC1995709 DOI: 10.1091/mbc.e06-12-1148] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
In Saccharomyces cerevisiae, minichromosome maintenance protein (Mcm) 10 interacts with DNA polymerase (pol)-alpha and functions as a nuclear chaperone for the catalytic subunit, which is rapidly degraded in the absence of Mcm10. We report here that the interaction between Mcm10 and pol-alpha is conserved in human cells. We used a small interfering RNA-based approach to deplete Mcm10 in HeLa cells, and we observed that the catalytic subunit of pol-alpha, p180, was degraded with similar kinetics as Mcm10, whereas the regulatory pol-alpha subunit, p68, remained unaffected. Simultaneous loss of Mcm10 and p180 inhibited S phase entry and led to an accumulation of already replicating cells in late S/G2 as a result of DNA damage, which triggered apoptosis in a subpopulation of cells. These phenotypes differed considerably from analogous studies in Drosophila embryo cells that did not exhibit a similar arrest. To further dissect the roles of Mcm10 and p180 in human cells, we depleted p180 alone and observed a significant delay in S phase entry and fork progression but little effect on cell viability. These results argue that cells can tolerate low levels of p180 as long as Mcm10 is present to "recycle" it. Thus, human Mcm10 regulates both replication initiation and elongation and maintains genome integrity.
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Affiliation(s)
- Sharbani Chattopadhyay
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455
| | - Anja-Katrin Bielinsky
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455
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43
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Semple JI, Smits VAJ, Fernaud JR, Mamely I, Freire R. Cleavage and degradation of Claspin during apoptosis by caspases and the proteasome. Cell Death Differ 2007; 14:1433-42. [PMID: 17431426 DOI: 10.1038/sj.cdd.4402134] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Apoptosis plays a crucial role in development and tissue homeostasis. Some key survival pathways, such as DNA damage checkpoints and DNA repair, have been described to be inactivated during apoptosis. Here, we describe the processing of the human checkpoint protein Claspin during apoptosis. We observed cleavage of Claspin into multiple fragments in vivo. In vitro cleavage with caspases 3 and 7 of various fragments of the protein, revealed cut sites near the N- and C-termini of the protein. Using mass spectrometry, we identified a novel caspase cleavage site in Claspin at Asp25. Importantly, in addition to cleavage by caspases, we observed a proteasome-dependent degradation of Claspin under apoptotic conditions, resulting in a reduction of the levels of both full-length Claspin and its cleavage products. This degradation was not dependent upon the DSGxxS phosphodegron motif required for SCF(beta-TrCP)-mediated ubiquitination of Claspin. Finally, downregulation of Claspin protein levels by short interfering RNA resulted in an increase in apoptotic induction both in the presence and absence of DNA damage. We conclude that Claspin has antiapoptotic activity and is degraded by two different pathways during apoptosis. The resulting disappearance of Claspin from the cells further promotes apoptosis.
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Affiliation(s)
- J I Semple
- Unidad de Investigación, Hospital Universitario de Canarias. Ofra s/n, La Cuesta, 38320 La Laguna, Tenerife, Spain.
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Okita N, Kudo Y, Tanuma SI. Checkpoint Kinase 1 Is Cleaved in a Caspase-Dependent Pathway during Genotoxic Stress-Induced Apoptosis. Biol Pharm Bull 2007; 30:359-62. [PMID: 17268080 DOI: 10.1248/bpb.30.359] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Checkpoint kinase 1 (Chk1) plays important roles in genotoxic stress-induced cell cycle checkpoint and in normal cell cycle progression. Here, we show that Chk1 is cleaved in the treatment of apoptotic dose of etoposide (ETP) or cisplatin (CIS) but not of viable dose in HeLa S3 cells. The cleavage of Chk1 was completely inhibited by an irreversible and cell-permeable pan-caspase inhibitor, N-benzyloxycarbonyl-Val-Ala-Asp (OMe) fluoromethylketone (z-VAD-fmk). These results identify Chk1 as a novel substrate that is cleaved by a caspase-dependent manner during genotoxic stress-induced apoptosis. Our data may also indicate the existence of a novel Chk1-regulated apoptotic pathway.
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Affiliation(s)
- Naoyuki Okita
- Department of Biochemistry, Faculty of Pharmaceutical Sciences, Tokyo University of Science, Chiba, Japan
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Shreeram S, Hee WK, Demidov ON, Kek C, Yamaguchi H, Fornace AJ, Anderson CW, Appella E, Bulavin DV. Regulation of ATM/p53-dependent suppression of myc-induced lymphomas by Wip1 phosphatase. ACTA ACUST UNITED AC 2006; 203:2793-9. [PMID: 17158963 PMCID: PMC2118180 DOI: 10.1084/jem.20061563] [Citation(s) in RCA: 108] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The ataxia telangiectasia mutated (ATM) kinase is a key tumor suppressor that regulates numerous cell cycle checkpoints as well as apoptosis. Here, we report that ATM is a critical player in the regulation of apoptosis and lymphomagenesis in the presence of c-myc. In turn, deletion of the inhibitory ATM phosphatase, Wip1, results in ATM up-regulation and suppression of Eμ-myc–induced B cell lymphomas. Using mouse genetic crosses, we show that the onset of myc-induced lymphomas is dramatically delayed in Wip1-null mice in an ATM- and p53-, but not p38 MAPK– or Arf-, dependent manner. We propose that Wip1 phosphatase is critical for regulating the ATM-mediated tumor surveillance network.
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Escaffit F, Vaute O, Chevillard-Briet M, Segui B, Takami Y, Nakayama T, Trouche D. Cleavage and cytoplasmic relocalization of histone deacetylase 3 are important for apoptosis progression. Mol Cell Biol 2006; 27:554-67. [PMID: 17101790 PMCID: PMC1800792 DOI: 10.1128/mcb.00869-06] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The apoptotic process is accompanied by major changes in chromatin structure and gene expression. The apoptotic genetic program is progressively set up with the inhibition of antiapoptotic genes and the activation of proapoptotic ones. Here, we show that the histone deacetylase 3 (HDAC-3), which is a known co-repressor of many proapoptotic genes, is subjected to proteolytic cleavage during apoptosis in a cell type- and species-independent manner. This cleavage is caspase dependent and leads to the loss of the C-terminal part of HDAC-3. The cleaved form of HDAC-3 accumulates in the cytoplasm. Furthermore, we found that forced nuclear localization of HDAC-3 decreases the efficiency of apoptosis induction, indicating that HDAC-3 cytoplasmic relocalization is important for the apoptotic process. Finally, we observed that HDAC-3 cleavage allowed increased histone acetylation and transcriptional activation on a proapoptotic HDAC-3-target gene, the Fas-encoding gene. Altogether, our results thus indicate that HDAC-3 cleavage is crucial for efficient apoptosis induction because it allows the activation of some proapoptotic genes during apoptosis progression.
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Affiliation(s)
- Fabrice Escaffit
- Laboratoire de Biologie Moléculaire Eucaryote, UMR5099, CNRS and Université Paul Sabatier, IFR109, 118 Route de Narbonne, 31062 Toulouse Cedex 4, France
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47
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Wang J, Pabla N, Wang CY, Wang W, Schoenlein PV, Dong Z. Caspase-mediated cleavage of ATM during cisplatin-induced tubular cell apoptosis: inactivation of its kinase activity toward p53. Am J Physiol Renal Physiol 2006; 291:F1300-7. [PMID: 16849690 DOI: 10.1152/ajprenal.00509.2005] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Cisplatin induces renal cell injury and death, resulting in nephrotoxicity that limits its use in cancer therapy. Using cell culture models, recent work has suggested the involvement of p53 in renal cell apoptosis during cisplatin treatment. However, the signals upstream of p53 remain elusive. ATM and ATR are critical regulators of p53 under various conditions of DNA damage. Here, we show that ATM, and not ATR, was proteolytically cleaved into specific fragments of approximately 210 and 150 kDa during cisplatin-induced tubular cell apoptosis. ATM cleavage was paralleled by the development of apoptosis. VAD, a broad-spectrum inhibitor of caspases, attenuated the cleavage of ATM, whereas the inhibitors of specific caspases were less effective. In caspase-3-deficient MCF-7 cells, ATM was cleaved, releasing the 210- but not the 150-kDa fragment. Recombinant caspase-3 was much more effective than caspase-7 in cleaving ATM that was immunoprecipitated from cell lysates. During cisplatin incubation, VAD protected ATM and enhanced p53 phosphorylation. In vitro assay of protein kinase activity further showed that ATM immunoprecipitated from cisplatin-treated cells had significantly lower kinase activity toward p53 than that from control cells. Importantly, the protein kinase activity was restored in ATM that was protected by VAD during cisplatin incubation. ATM deficiency sensitized the cells to cisplatin-induced apoptosis, suggesting a cytoprotective role of ATM in this experimental model. Thus proteolysis of ATM by caspases may inactivate this regulatory molecule to facilitate the progression of apoptosis.
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Affiliation(s)
- Jinzhao Wang
- Department of Cellular Biology and Anatomy, Medical College of Georgia, 1459 Laney Walker Blvd., Augusta, GA 30912, USA
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Mukherjee B, Kessinger C, Kobayashi J, Chen BPC, Chen DJ, Chatterjee A, Burma S. DNA-PK phosphorylates histone H2AX during apoptotic DNA fragmentation in mammalian cells. DNA Repair (Amst) 2006; 5:575-90. [PMID: 16567133 DOI: 10.1016/j.dnarep.2006.01.011] [Citation(s) in RCA: 151] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2005] [Revised: 01/11/2006] [Accepted: 01/17/2006] [Indexed: 11/28/2022]
Abstract
The phosphorylation of histone H2AX at serine 139 is one of the earliest responses of mammalian cells to ionizing radiation-induced DNA breaks. DNA breaks are also generated during the terminal stages of apoptosis when chromosomal DNA is cleaved into oligonucleosomal pieces. Apoptotic DNA fragmentation and the consequent chromatin condensation are important for efficient clearing of genomic DNA and nucleosomes and for protecting the organism from auto-immmunization and oncogenic transformation. In this study, we demonstrate that H2AX is phosphorylated during apoptotic DNA fragmentation in mouse, Chinese hamster ovary, and human cells. We have previously shown that ataxia telangiectasia mutated kinase (ATM) is primarily responsible for H2AX phosphorylation in murine cells in response to ionizing radiation. Interestingly, we find here that DNA-dependent protein kinase (DNA-PK) is solely responsible for H2AX phosphorylation during apoptosis while ATM is dispensable for the process. Moreover, the kinase activity of DNA-PKcs (catalytic subunit of DNA-PK) is specifically required for the induction of gammaH2AX. We further show that DNA-PKcs is robustly activated in apoptotic cells, as evidenced by autophosphorylation at serine 2056, before it is inactivated by cleavage. In contrast, ATM is degraded well before DNA fragmentation and gammaH2AX induction resulting in the predominance of DNA-PK during the later stages of apoptosis. Finally, we show that DNA-PKcs autophosphorylation and gammaH2AX induction occur only in apoptotic nuclei with characteristic chromatin condensation but not in non-apoptotic nuclei from the same culture establishing the most direct link between DNA fragmentation, DNA-PKcs activation, and H2AX phosphorylation. It is well established that DNA-PK is inactivated by cleavage late in apoptosis in order to forestall DNA repair. Our results demonstrate, for the first time, that DNA-PK is actually activated in late apoptotic cells and is able to initiate an early step in the DNA-damage response, namely H2AX phosphorylation, before it is inactivated by proteolysis.
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Affiliation(s)
- Bipasha Mukherjee
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, 2201 Inwood Road, NC-7.206, Dallas, TX 75390, USA
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49
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Dumay A, Laulier C, Bertrand P, Saintigny Y, Lebrun F, Vayssière JL, Lopez BS. Bax and Bid, two proapoptotic Bcl-2 family members, inhibit homologous recombination, independently of apoptosis regulation. Oncogene 2006; 25:3196-205. [PMID: 16407825 DOI: 10.1038/sj.onc.1209344] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
In order to analyse the relationships between regulation of apoptosis and homologous recombination (HR), we overexpressed proapoptotic Bax or only-BH3 Bid proteins or antiapoptotic Bcl-2 or Bcl-XL, in hamster CHO cells or in SV40-transformed human fibroblasts. We measured HR induced by gamma-rays, UVC or a specific double-strand cleavage targeted in the recombination substrate by the meganuclease I-SceI. We show here that the induction of both recombinant cells and recombinant colonies was impaired when expressing Bcl-2 family members, in hamster as well as in human cells. Moreover, the pro- as well as antiapoptotic Bcl-2 family members inhibited HR, independently of degradation of the RAD51 recombination protein and of their impact on apoptosis. These data reveal a mechanism of HR downregulation by potentially proapoptotic proteins, distinct from and parallel to degradation of recombination proteins, a situation that should also optimize the efficiency of programmed cell death.
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Affiliation(s)
- A Dumay
- UMR 217 CNRS/CEA, DSV, DRR, Fontenay aux Roses Cédex, France
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50
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Meier M, den Boer ML, Hall AG, Irving JAE, Passier M, Minto L, van Wering ER, Janka-Schaub GE, Pieters R. Relation between genetic variants of the ataxia telangiectasia-mutated (ATM) gene, drug resistance, clinical outcome and predisposition to childhood T-lineage acute lymphoblastic leukaemia. Leukemia 2005; 19:1887-95. [PMID: 16167060 DOI: 10.1038/sj.leu.2403943] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The T-lineage phenotype in children with acute lymphoblastic leukaemia (ALL) is associated with in vitro drug resistance and a higher relapse-risk compared to a precursor B phenotype. Our study was aimed to investigate whether mutations in the ATM gene occur in childhood T-lineage acute lymphoblastic leukaemia (T-ALL) that are linked to drug resistance and clinical outcome. In all, 20 different single nucleotide substitutions were found in 16 exons of ATM in 62/103 (60%) T-ALL children and 51/99 (52%, P = 0.21) controls. Besides the well-known polymorphism D1853N, five other alterations (S707P, F858L, P1054R, L1472W, Y1475C) in the coding part of ATM were found. These five coding alterations seem to occur more frequently in T-ALL (13%) than controls (5%, P = 0.06), but did not associate with altered expression levels of ATM or in vitro resistance to daunorubicin. However, T-ALL patients carrying these five coding alterations presented with a higher white blood cell count at diagnosis (P = 0.05) and show an increased relapse-risk (5-year probability of disease-free survival (pDFS) = 48%) compared to patients with other alterations or wild-type ATM (5-year pDFS = 76%, P = 0.05). The association between five coding ATM alterations in T-ALL, their germline presence, white blood cell count and unfavourable outcome may point to a role for ATM in the development of T-ALL in these children.
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Affiliation(s)
- M Meier
- Department of Paediatric Oncology/Haematology, Erasmus MC/Sophia Children's Hospital, Erasmus University Medical Centre, Rotterdam, The Netherlands
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