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Chan CY, Chen Z, Destro G, Veal M, Lau D, O’Neill E, Dias G, Mosley M, Kersemans V, Guibbal F, Gouverneur V, Cornelissen B. Imaging PARP with [ 18F]rucaparib in pancreatic cancer models. Eur J Nucl Med Mol Imaging 2022; 49:3668-3678. [PMID: 35614267 PMCID: PMC9399069 DOI: 10.1007/s00259-022-05835-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Accepted: 05/08/2022] [Indexed: 12/27/2022]
Abstract
PURPOSE Rucaparib, an FDA-approved PARP inhibitor, is used as a single agent in maintenance therapy to provide promising treatment efficacy with an acceptable safety profile in various types of BRCA-mutated cancers. However, not all patients receive the same benefit from rucaparib-maintenance therapy. A predictive biomarker to help with patient selection for rucaparib treatment and predict clinical benefit is therefore warranted. With this aim, we developed [18F]rucaparib, an 18F-labelled isotopologue of rucaparib, and employed it as a PARP-targeting agent for cancer imaging with PET. Here, we report the in vitro and in vivo evaluation of [18F]rucaparib in human pancreatic cancer models. METHOD We incorporated the positron-emitting 18F isotope into rucaparib, enabling its use as a PET imaging agent. [18F]rucaparib binds to the DNA damage repair enzyme, PARP, allowing direct visualisation and measurement of PARP in cancerous models before and after PARP inhibition or other genotoxic cancer therapies, providing critical information for cancer diagnosis and therapy. Proof-of-concept evaluations were determined in pancreatic cancer models. RESULTS Uptake of [18F]rucaparib was found to be mainly dependent on PARP1 expression. Induction of DNA damage increased PARP expression, thereby increasing uptake of [18F]rucaparib. In vivo studies revealed relatively fast blood clearance of [18F]rucaparib in PSN1 tumour-bearing mice, with a tumour uptake of 5.5 ± 0.5%ID/g (1 h after i.v. administration). In vitro and in vivo studies showed significant reduction of [18F]rucaparib uptake by addition of different PARP inhibitors, indicating PARP-selective binding. CONCLUSION Taken together, we demonstrate the potential of [18F]rucaparib as a non-invasive PARP-targeting imaging agent for pancreatic cancers.
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Affiliation(s)
- Chung Ying Chan
- Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Old Road Campus Research Building, Off Roosevelt Drive, OX3 7DQ Oxford, UK
| | - Zijun Chen
- Department of Chemistry, Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford, OX1 3TA UK
| | - Gianluca Destro
- Department of Chemistry, Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford, OX1 3TA UK
| | - Mathew Veal
- Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Old Road Campus Research Building, Off Roosevelt Drive, OX3 7DQ Oxford, UK
| | - Doreen Lau
- Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Old Road Campus Research Building, Off Roosevelt Drive, OX3 7DQ Oxford, UK
| | - Edward O’Neill
- Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Old Road Campus Research Building, Off Roosevelt Drive, OX3 7DQ Oxford, UK
| | - Gemma Dias
- Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Old Road Campus Research Building, Off Roosevelt Drive, OX3 7DQ Oxford, UK
| | - Michael Mosley
- Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Old Road Campus Research Building, Off Roosevelt Drive, OX3 7DQ Oxford, UK
| | - Veerle Kersemans
- Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Old Road Campus Research Building, Off Roosevelt Drive, OX3 7DQ Oxford, UK
| | - Florian Guibbal
- Department of Chemistry, Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford, OX1 3TA UK
| | - Véronique Gouverneur
- Department of Chemistry, Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford, OX1 3TA UK
| | - Bart Cornelissen
- Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Old Road Campus Research Building, Off Roosevelt Drive, OX3 7DQ Oxford, UK
- Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
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Osmotic Stress Interferes with DNA Damage Response and H2AX Phosphorylation in Human Keratinocytes. Cells 2022; 11:cells11060959. [PMID: 35326410 PMCID: PMC8946833 DOI: 10.3390/cells11060959] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 03/02/2022] [Accepted: 03/04/2022] [Indexed: 12/07/2022] Open
Abstract
The human skin and in particular its outermost layer, the epidermis, protects the body from potentially harmful substances, radiation as well as excessive water loss. However, the interference between the various stress responses of the epidermal keratinocytes, which often occur simultaneously, is largely unknown. The focus of this study was to investigate the interference between osmotic stress and DNA damage response. In addition to revealing the already well-described regulation of diverse gene sets, for example, cellular processes such as transcription, translation, and metabolic pathways (e.g., the KEGG citrate cycle and Reactome G2/M checkpoints), gene expression analysis of osmotically stressed keratinocytes revealed an influence on the transcription of genes also related to UV-induced DNA damage response. A gene network regulating the H2AX phosphorylation was identified to be regulated by osmotic stress. To analyze and test the interference between osmotic stress and DNA damage response, which can be triggered by UV stress on the one hand and oxidative stress on the other, in more detail, primary human keratinocytes were cultured under osmotic stress conditions and subsequently exposed to UV light and H2O2, respectively. γH2AX measurements revealed lower γH2AX levels in cells previously cultured under osmotic stress conditions.
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Chen C, Enomoto A, Weng L, Taki T, Shiraki Y, Mii S, Ichihara R, Kanda M, Koike M, Kodera Y, Takahashi M. Complex roles of the actin-binding protein Girdin/GIV in DNA damage-induced apoptosis of cancer cells. Cancer Sci 2020; 111:4303-4317. [PMID: 32875699 PMCID: PMC7648047 DOI: 10.1111/cas.14637] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 08/19/2020] [Accepted: 08/23/2020] [Indexed: 12/24/2022] Open
Abstract
The actin‐binding protein Girdin is a hub protein that interacts with multiple proteins to regulate motility and Akt and trimeric G protein signaling in cancer cells. Girdin expression correlates with poor outcomes in multiple human cancers. However, those findings are not universal, as they depend on study conditions. Those data suggest that multiple aspects of Girdin function and its role in tumor cell responses to anticancer therapeutics must be reconsidered. In the present study, we found that Girdin is involved in DNA damage‐induced cancer cell apoptosis. An esophageal cancer cell line that exhibited high Girdin expression showed a marked sensitivity to UV‐mediated DNA damage compared to a line with low Girdin expression. When transcriptional activation of endogenous Girdin was mediated by an engineered CRISPR/Cas9 activation system, sensitivity to DNA damage increased in both stationary and migrating HeLa cancer cells. High Girdin expression was associated with dysregulated cell cycle progression and prolonged G1 and M phases. These features were accompanied by p53 activation, which conceivably increases cancer cell vulnerability to UV exposure. These data highlight the importance of understanding complex Girdin functions that influence cancer cell sensitivity to therapeutics.
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Affiliation(s)
- Chen Chen
- Department of Pathology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Atsushi Enomoto
- Department of Pathology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Liang Weng
- Center for Molecular Medicine, Xiangya Hospital, Central South University, Changsha, China.,Key Laboratory of Molecular Radiation Oncology Hunan Province, Changsha, China
| | - Tetsuro Taki
- Department of Pathology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Yukihiro Shiraki
- Department of Pathology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Shinji Mii
- Department of Pathology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Ryosuke Ichihara
- Department of Pathology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Mitsuro Kanda
- Department of Gastroenterological Surgery (Surgery II), Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Masahiko Koike
- Department of Gastroenterological Surgery (Surgery II), Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Yasuhiro Kodera
- Department of Gastroenterological Surgery (Surgery II), Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Masahide Takahashi
- Department of Pathology, Nagoya University Graduate School of Medicine, Nagoya, Japan.,International Center for Cell and Gene Therapy, Fujita Health University, Toyoake, Japan
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4
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A Single Radioprotective Dose of Prostaglandin E 2 Blocks Irradiation-Induced Apoptotic Signaling and Early Cycling of Hematopoietic Stem Cells. Stem Cell Reports 2020; 15:358-373. [PMID: 32735825 PMCID: PMC7419738 DOI: 10.1016/j.stemcr.2020.07.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2020] [Revised: 07/02/2020] [Accepted: 07/03/2020] [Indexed: 10/24/2022] Open
Abstract
Ionizing radiation exposure results in acute and delayed bone marrow suppression. Treatment of mice with 16,16-dimethyl prostaglandin E2 (dmPGE2) prior to lethal ionizing radiation (IR) facilitates survival, but the cellular and molecular mechanisms are unclear. In this study we show that dmPGE2 attenuates loss and enhances recovery of bone marrow cellularity, corresponding to a less severe hematopoietic stem cell nadir, and significantly preserves long-term repopulation capacity and progenitor cell function. Mechanistically, dmPGE2 suppressed hematopoietic stem cell (HSC) proliferation through 24 h post IR, which correlated with fewer DNA double-strand breaks and attenuation of apoptosis, mitochondrial compromise, oxidative stress, and senescence. RNA sequencing of HSCs at 1 h and 24 h post IR identified a predominant interference with IR-induced p53-downstream gene expression at 1 h, and confirmed the suppression of IR-induced cell-cycle genes at 24 h. These data identify mechanisms of dmPGE2 radioprotection and its potential role as a medical countermeasure against radiation exposure.
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Cabezas M, García-Quevedo L, Alonso C, Manubens M, Álvarez Y, Barquinero JF, Ramón Y Cajal S, Ortega M, Blanco A, Caballín MR, Armengol G. Polymorphisms in MDM2 and TP53 Genes and Risk of Developing Therapy-Related Myeloid Neoplasms. Sci Rep 2019; 9:150. [PMID: 30655613 PMCID: PMC6336808 DOI: 10.1038/s41598-018-36931-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Accepted: 11/22/2018] [Indexed: 12/28/2022] Open
Abstract
One of the most severe complications after successful cancer therapy is the development of therapy-related myeloid neoplasms (t-MN). Constitutional genetic variation is likely to impact on t-MN risk. We aimed to evaluate if polymorphisms in the p53 pathway can be useful for predicting t-MN susceptibility. First, an association study revealed that the Pro variant of the TP53 Arg72Pro polymorphism and the G allele of the MDM2 SNP309 were associated with t-MN risk. The Arg variant of TP53 is more efficient at inducing apoptosis, whereas the Pro variant is a more potent inductor of cell cycle arrest and DNA repair. As regards MDM2 SNP309, the G allele is associated with attenuation of the p53 apoptotic response. Second, to evaluate the biological effect of the TP53 polymorphism, we established Jurkat isogenic cell lines expressing p53Arg or p53Pro. Jurkat p53Arg cells presented higher DNA damage and higher apoptotic potential than p53Pro cells, after treatment with chemotherapy agents. Only p53Pro cells presented t(15;17) translocation and del(5q). We suggest that failure to repair DNA lesions in p53Arg cells would lead them to apoptosis, whereas some p53Pro cells, prone to cell cycle arrest and DNA repair, could undergo misrepair, generating chromosomal abnormalities typical of t-MN.
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Affiliation(s)
- Maria Cabezas
- Unit of Biological Anthropology, Department of Animal Biology, Plant Biology and Ecology, Faculty of Biosciences, Universitat Autònoma de Barcelona, 08193, Bellaterra, Catalonia, Spain
| | - Lydia García-Quevedo
- Unit of Biological Anthropology, Department of Animal Biology, Plant Biology and Ecology, Faculty of Biosciences, Universitat Autònoma de Barcelona, 08193, Bellaterra, Catalonia, Spain
| | - Cintia Alonso
- Unit of Biological Anthropology, Department of Animal Biology, Plant Biology and Ecology, Faculty of Biosciences, Universitat Autònoma de Barcelona, 08193, Bellaterra, Catalonia, Spain
| | - Marta Manubens
- Unit of Biological Anthropology, Department of Animal Biology, Plant Biology and Ecology, Faculty of Biosciences, Universitat Autònoma de Barcelona, 08193, Bellaterra, Catalonia, Spain
| | - Yolanda Álvarez
- Unit of Biological Anthropology, Department of Animal Biology, Plant Biology and Ecology, Faculty of Biosciences, Universitat Autònoma de Barcelona, 08193, Bellaterra, Catalonia, Spain
| | - Joan Francesc Barquinero
- Unit of Biological Anthropology, Department of Animal Biology, Plant Biology and Ecology, Faculty of Biosciences, Universitat Autònoma de Barcelona, 08193, Bellaterra, Catalonia, Spain
| | - Santiago Ramón Y Cajal
- Department of Pathology, Vall d'Hebron University Hospital, 08035, Barcelona, Catalonia, Spain.,Spanish Biomedical Research Network Centre in Oncology (CIBERONC), Barcelona, Catalonia, Spain
| | - Margarita Ortega
- Department of Hematology, Vall d'Hebron University Hospital, 08035, Barcelona, Catalonia, Spain
| | - Adoración Blanco
- Department of Hematology, Vall d'Hebron University Hospital, 08035, Barcelona, Catalonia, Spain
| | - María Rosa Caballín
- Unit of Biological Anthropology, Department of Animal Biology, Plant Biology and Ecology, Faculty of Biosciences, Universitat Autònoma de Barcelona, 08193, Bellaterra, Catalonia, Spain
| | - Gemma Armengol
- Unit of Biological Anthropology, Department of Animal Biology, Plant Biology and Ecology, Faculty of Biosciences, Universitat Autònoma de Barcelona, 08193, Bellaterra, Catalonia, Spain.
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Chang JF, Hsu JL, Sheng YH, Leu WJ, Yu CC, Chan SH, Chan ML, Hsu LC, Liu SP, Guh JH. Phosphodiesterase Type 5 (PDE5) Inhibitors Sensitize Topoisomerase II Inhibitors in Killing Prostate Cancer Through PDE5-Independent Impairment of HR and NHEJ DNA Repair Systems. Front Oncol 2019; 8:681. [PMID: 30705876 PMCID: PMC6344441 DOI: 10.3389/fonc.2018.00681] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Accepted: 12/27/2018] [Indexed: 01/17/2023] Open
Abstract
Human castration-resistant prostate cancer (CRPC) is a significant target of clinical research. The use of DNA-damaging agents has a long history in cancer chemotherapy but is limited by their toxicities. The combination with a safer drug can be a strategy in reducing dosage and toxicity while increasing anticancer activity in CRPC treatment. Phosphodiesterase type 5 (PDE5) inhibitors are used to treat erectile dysfunction through the selective inhibition of PDE5 that is responsible for cGMP degradation in the corpus cavernosum. Several studies have reported that PDE5 inhibitors display protective effect against doxorubicin-induced cardiotoxicity. The combinatory treatment of CRPC with doxorubicin and PDE5 inhibitors has been studied accordingly. The data demonstrated that sildenafil or vardenafil (two structure-related PDE5 inhibitors) but not tadalafil (structure-unrelated to sildenafil) sensitized doxorubicin-induced apoptosis in CRPC cells with deteriorating the down-regulation of anti-apoptotic Bcl-2 family members, including Bcl-xL and Mcl-1, and amplifying caspase activation. Homologous recombination (HR) and non-homologous end joining (NHEJ) DNA repair systems were inhibited in the apoptotic sensitization through detection of nuclear foci formation of Rad51 and DNA end-binding of Ku80. PDE5 knockdown to mimic the exposure to PDE5 inhibitors did not reproduce apoptotic sensitization, suggesting a PDE5-independent mechanism. Not only doxorubicin, sildenafil combined with other inhibitors of topoisomerase II but not topoisomerase I also triggered apoptotic sensitization. In conclusion, the data suggest that sildenafil and vardenafil induce PDE5-independent apoptotic sensitization to doxorubicin (or other topoisomerase II inhibitors) through impairment of both HR and NHEJ repair systems that are evident by a decrease of nuclear Rad51 levels and their foci formation in the nucleus, and an inhibition of Ku80 DNA end-binding capability. The combinatory treatment may enable an important strategy for anti-CRPC development.
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Affiliation(s)
- Jo-Fan Chang
- School of Pharmacy, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Jui-Ling Hsu
- School of Pharmacy, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Yi-Hua Sheng
- School of Pharmacy, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Wohn-Jenn Leu
- School of Pharmacy, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Chia-Chun Yu
- School of Pharmacy, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - She-Hung Chan
- School of Pharmacy, College of Medicine, National Taiwan University, Taipei, Taiwan.,Department of Cosmetic Science, Providence University, Taichung, Taiwan
| | - Mei-Ling Chan
- School of Pharmacy, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Lih-Ching Hsu
- School of Pharmacy, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Shih-Ping Liu
- Department of Urology, National Taiwan University Hospital and College of Medicine, Taipei, Taiwan
| | - Jih-Hwa Guh
- School of Pharmacy, College of Medicine, National Taiwan University, Taipei, Taiwan
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7
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Tomita T, Ieguchi K, Takita M, Tsukahara F, Yamada M, Egly JM, Maru Y. C1D is not directly involved in the repair of UV-damaged DNA but protects cells from oxidative stress by regulating gene expressions in human cell lines. J Biochem 2019; 164:415-426. [PMID: 30165670 DOI: 10.1093/jb/mvy069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Accepted: 08/24/2018] [Indexed: 11/14/2022] Open
Abstract
A small nuclear protein, C1D, has roles in various cellular processes, transcription regulation, genome stability surveillance, DNA repair and RNA processing, all of which are required to maintain the host life cycles. In the previous report, C1D directly interacts with XPB, a component of the nucleotide excision repair complex, and C1D knockdown reduced cell survival of 27-1 cells, CHO derivative cells, after UV irradiation. To find out the role of C1D in UV-damaged cells, we used human cell lines with siRNA or shRNA to knockdown C1D. C1D knockdown reduced cell survival rates of LU99 and 786-O after UV irradiation, although C1D knockdown did not affect the efficiency of the nucleotide excision repair. Immunostaining data support that C1D is not directly involved in the DNA repair process in UV-damaged cells. However, H2O2 treatment reduced cell viability in LU99 and 786-O cells. We also found that C1D knockdown upregulated DDIT3 expression in LU99 cells and downregulated APEX1 in 786-O cells, suggesting that C1D functions as a co-repressor/activator. The data accounts for the reduction of cell survival rates upon UV irradiation.
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Affiliation(s)
- Takeshi Tomita
- Department of Pharmacology, Tokyo Women's Medical University, 8-1 Kawada, Shinjuku, Tokyo, Japan
| | - Katsuaki Ieguchi
- Department of Pharmacology, Tokyo Women's Medical University, 8-1 Kawada, Shinjuku, Tokyo, Japan
| | - Morichika Takita
- Department of Pharmacology, Tokyo Women's Medical University, 8-1 Kawada, Shinjuku, Tokyo, Japan
| | - Fujiko Tsukahara
- Department of Pharmacology, Tokyo Women's Medical University, 8-1 Kawada, Shinjuku, Tokyo, Japan
| | - Masayuki Yamada
- Center for Medical Education, Graduate School of Medicine, Kyoto University, Yoshida-Konoe-cho, Sakyo-ku, Kyoto, Japan
| | - Jean-Marc Egly
- Institut de Génétique et de Biologie Moléculaire et Cellulaire CNRS/INSERM/UdS 1, rue Laurent Fries, BP163 F-67404 Illkirch Cedex, France
| | - Yoshiro Maru
- Department of Pharmacology, Tokyo Women's Medical University, 8-1 Kawada, Shinjuku, Tokyo, Japan
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Xia Y, Ivanovska IL, Zhu K, Smith L, Irianto J, Pfeifer CR, Alvey CM, Ji J, Liu D, Cho S, Bennett RR, Liu AJ, Greenberg RA, Discher DE. Nuclear rupture at sites of high curvature compromises retention of DNA repair factors. J Cell Biol 2018; 217:3796-3808. [PMID: 30171044 PMCID: PMC6219729 DOI: 10.1083/jcb.201711161] [Citation(s) in RCA: 105] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Revised: 05/24/2018] [Accepted: 08/20/2018] [Indexed: 02/07/2023] Open
Abstract
The nucleus is physically linked to the cytoskeleton, adhesions, and extracellular matrix-all of which sustain forces, but their relationships to DNA damage are obscure. We show that nuclear rupture with cytoplasmic mislocalization of multiple DNA repair factors correlates with high nuclear curvature imposed by an external probe or by cell attachment to either aligned collagen fibers or stiff matrix. Mislocalization is greatly enhanced by lamin A depletion, requires hours for nuclear reentry, and correlates with an increase in pan-nucleoplasmic foci of the DNA damage marker γH2AX. Excess DNA damage is rescued in ruptured nuclei by cooverexpression of multiple DNA repair factors as well as by soft matrix or inhibition of actomyosin tension. Increased contractility has the opposite effect, and stiff tumors with low lamin A indeed exhibit increased nuclear curvature, more frequent nuclear rupture, and excess DNA damage. Additional stresses likely play a role, but the data suggest high curvature promotes nuclear rupture, which compromises retention of DNA repair factors and favors sustained damage.
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Affiliation(s)
- Yuntao Xia
- Physical Sciences Oncology Center at Penn, University of Pennsylvania, Philadelphia, PA ,Molecular and Cell Biophysics Lab, University of Pennsylvania, Philadelphia, PA
| | - Irena L. Ivanovska
- Physical Sciences Oncology Center at Penn, University of Pennsylvania, Philadelphia, PA ,Molecular and Cell Biophysics Lab, University of Pennsylvania, Philadelphia, PA
| | - Kuangzheng Zhu
- Physical Sciences Oncology Center at Penn, University of Pennsylvania, Philadelphia, PA ,Molecular and Cell Biophysics Lab, University of Pennsylvania, Philadelphia, PA
| | - Lucas Smith
- Physical Sciences Oncology Center at Penn, University of Pennsylvania, Philadelphia, PA ,Molecular and Cell Biophysics Lab, University of Pennsylvania, Philadelphia, PA
| | - Jerome Irianto
- Physical Sciences Oncology Center at Penn, University of Pennsylvania, Philadelphia, PA ,Molecular and Cell Biophysics Lab, University of Pennsylvania, Philadelphia, PA
| | - Charlotte R. Pfeifer
- Physical Sciences Oncology Center at Penn, University of Pennsylvania, Philadelphia, PA ,Molecular and Cell Biophysics Lab, University of Pennsylvania, Philadelphia, PA
| | - Cory M. Alvey
- Physical Sciences Oncology Center at Penn, University of Pennsylvania, Philadelphia, PA ,Molecular and Cell Biophysics Lab, University of Pennsylvania, Philadelphia, PA,Graduate Group, Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA
| | - Jiazheng Ji
- Physical Sciences Oncology Center at Penn, University of Pennsylvania, Philadelphia, PA ,Molecular and Cell Biophysics Lab, University of Pennsylvania, Philadelphia, PA
| | - Dazhen Liu
- Physical Sciences Oncology Center at Penn, University of Pennsylvania, Philadelphia, PA ,Molecular and Cell Biophysics Lab, University of Pennsylvania, Philadelphia, PA
| | - Sangkyun Cho
- Physical Sciences Oncology Center at Penn, University of Pennsylvania, Philadelphia, PA ,Molecular and Cell Biophysics Lab, University of Pennsylvania, Philadelphia, PA
| | - Rachel R. Bennett
- Physical Sciences Oncology Center at Penn, University of Pennsylvania, Philadelphia, PA ,Graduate Group, Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA
| | - Andrea J. Liu
- Physical Sciences Oncology Center at Penn, University of Pennsylvania, Philadelphia, PA ,Graduate Group, Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA
| | - Roger A. Greenberg
- Physical Sciences Oncology Center at Penn, University of Pennsylvania, Philadelphia, PA ,Cancer Biology, Abramson Family Cancer Research Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Dennis E. Discher
- Physical Sciences Oncology Center at Penn, University of Pennsylvania, Philadelphia, PA ,Molecular and Cell Biophysics Lab, University of Pennsylvania, Philadelphia, PA,Graduate Group, Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA,Correspondence to Dennis E. Discher:
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9
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Guérard M, Marchand C, Funk J, Christen F, Winter M, Zeller A. DNA Damage Response of 4-Chloro-Ortho-Toluidine in Various Rat Tissues. Toxicol Sci 2018; 163:516-524. [DOI: 10.1093/toxsci/kfy054] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Melanie Guérard
- Pharmaceutical Sciences, Roche Pharma Research and Early Development, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, 4070 Basel, Switzerland
| | - Christine Marchand
- Pharmaceutical Sciences, Roche Pharma Research and Early Development, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, 4070 Basel, Switzerland
| | - Jürgen Funk
- Pharmaceutical Sciences, Roche Pharma Research and Early Development, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, 4070 Basel, Switzerland
| | - Francois Christen
- Pharmaceutical Sciences, Roche Pharma Research and Early Development, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, 4070 Basel, Switzerland
| | - Michael Winter
- Pharmaceutical Sciences, Roche Pharma Research and Early Development, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, 4070 Basel, Switzerland
| | - Andreas Zeller
- Pharmaceutical Sciences, Roche Pharma Research and Early Development, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, 4070 Basel, Switzerland
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10
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Hershman JM, France B, Hon K, Damoiseaux R. Direct quantification of gamma H2AX by cell-based high throughput screening for evaluation of genotoxicity of pesticides in a human thyroid cell lines. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2017; 58:522-528. [PMID: 28640454 PMCID: PMC6550478 DOI: 10.1002/em.22103] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Revised: 05/08/2017] [Accepted: 05/08/2017] [Indexed: 06/01/2023]
Abstract
Genotoxicity is thought to be the cause of many cancers. Genotoxicity due to environmental toxins may be partly responsible for the dramatic increase in the incidence of papillary thyroid cancer over the past two decades. Here, we present a fully automatable assay platform that directly quantifies the phosphorylation of nuclear histone gamma H2AX (γH2AX), a specific cellular marker for DNA double strand breaks (DSBs) via immunohistochemistry and laser scanning cytometry. It multiplexes γH2AX with total cell number measured as propidium iodide and calculates the percentage of cells with DSBs. Validation of this assay using NTHY-ori-3-1 human thyroid cells and etoposide showed that it was an excellent choice for high throughput applications. We used the assay to test the genotoxic effects of the EPA Toxcast Phase 1 pesticide library of 309 compounds. Compounds were evaluated in dose response and the DSB was quantified. We found that 19 pesticides induce DSB in vitro, highlighting a need to further assess these pesticides for their long-term oncogenic effects on the thyroid gland. Environ. Mol. Mutagen. 58:522-528, 2017. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Jerome M. Hershman
- West Los Angeles VA Medical Center, David Geffen School of Medicine at UCLA, Los Angeles, California
| | - Bryan France
- University of California Los Angeles, California NanoSystems Institute, Los Angeles, California
| | - Kevin Hon
- West Los Angeles VA Medical Center, David Geffen School of Medicine at UCLA, Los Angeles, California
| | - Robert Damoiseaux
- Department of Medicinal and Molecular Pharmacology, California Nano Systems Institute, Los Angeles, California
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11
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Nikolova T, Marini F, Kaina B. Genotoxicity testing: Comparison of the γH2AX focus assay with the alkaline and neutral comet assays. MUTATION RESEARCH-GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2017; 822:10-18. [PMID: 28844237 DOI: 10.1016/j.mrgentox.2017.07.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Revised: 07/14/2017] [Accepted: 07/17/2017] [Indexed: 10/19/2022]
Abstract
Genotoxicity testing relies on the quantitative measurement of adverse effects, such as chromosome aberrations, micronuclei, and mutations, resulting from primary DNA damage. Ideally, assays will detect DNA damage and cellular responses with high sensitivity, reliability, and throughput. Several novel genotoxicity assays may fulfill these requirements, including the comet assay and the more recently developed γH2AX assay. Although they are thought to be specific for genotoxicants, a systematic comparison of the assays has not yet been undertaken. In the present study, we compare the γH2AX focus assay with the alkaline and neutral versions of the comet assay, as to their sensitivities and limitations for detection of genetic damage. We investigated the dose-response relationships of γH2AX foci and comet tail intensities at various times following treatment with four prototypical genotoxicants, methyl methanesulfonate (MMS), N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), mitomycin C, and hydrogen peroxide (H2O2) and we tested whether there is a correlation between the endpoints, i.e., alkali-labile sites and DNA strand breaks on the one hand and the cell's response to DNA double-strand breaks and blocked replication forks on the other. Induction of γH2AX foci gave a linear dose response and all agents tested were positive in the assay. The increase in comet tail intensity was also a function of dose; however, mitomycin C was almost completely ineffective in the comet assay, and the doses needed to achieve a significant effect were somewhat higher for some treatments in the comet assay than in the γH2AX foci assay, which was confirmed by threshold analysis. There was high correlation between tail intensity and γH2AX foci for MMS and H2O2, less for MNNG, and none for mitomycin C. From this we infer that the γH2AX foci assay is more reliable, sensitive, and robust than the comet assay for detecting genotoxicant-induced DNA damage.
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Affiliation(s)
- Teodora Nikolova
- Institute of Toxicology, University Medical Center, Mainz, Germany
| | - Federico Marini
- Institute of Medical Biostatistics, Epidemiology and Informatics, University Medical Center, Mainz, Germany
| | - Bernd Kaina
- Institute of Toxicology, University Medical Center, Mainz, Germany.
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12
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Sun B, Ross SM, Rowley S, Adeleye Y, Clewell RA. Contribution of ATM and ATR kinase pathways to p53-mediated response in etoposide and methyl methanesulfonate induced DNA damage. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2017; 58:72-83. [PMID: 28195382 DOI: 10.1002/em.22070] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Revised: 12/06/2016] [Accepted: 12/07/2016] [Indexed: 06/06/2023]
Abstract
p53 is a key integrator of cellular response to DNA damage, supporting post-translational repair and driving transcription-mediated responses including cell cycle arrest, apoptosis, and repair. DNA damage sensing kinases recognize different types of DNA damage and initiate specific responses through various post-translational modifications of p53. This study evaluated chemical specificity of the p53 pathway response by manipulating p53 or its upstream kinases and assessing the effect on DNA damage and cellular responses to prototype chemicals: etoposide (ETP, topoisomerase II inhibitor) and methyl methane sulfonate (MMS, alkylating agent). p53-deficient cells demonstrated reduced accumulation of the p53 target proteins MDM2, p21, and Wip1; reduced apoptotic response; and increased DNA damage (p-H2AX and micronuclei) with both chemicals. However, p53 was not essential for cell cycle arrest in HT1080 or HCT116 cells. The two chemicals induced different patterns of kinase activation, particularly in terms of Chk 1, Chk 2, p38, and ERK 1/2. However, inhibition of the ATM pathway showed a greater effect on p53 activtation, apoptosis, and accumulation of DNA damage than ATR-Chk 1 or the MAP kinases regardless of the chemical used. These results indicate that ATM is the predominant upstream kinase responsible for activation of the p53-mediated DNA damage response for both MMS and ETP, though the downstream kinase response is markedly different. Environ. Mol. Mutagen. 58:72-83, 2017. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Bin Sun
- The Hamner Institutes for Health Sciences, Research Triangle Park, North Carolina, 27709
| | - Susan M Ross
- ScitoVation, LLC, Research Triangle Park, NC, 27709
| | - Sean Rowley
- ScitoVation, LLC, Research Triangle Park, NC, 27709
| | - Yeyejide Adeleye
- Unilever, Safety and Environmental Assurance Centre, Colworth Science Park, Sharnbrook, Bedfordshire, MK44 1LQ, United Kingdom
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13
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Solovjeva L, Firsanov D, Pleskach N, Svetlova M. Immunofluorescence Analysis of γ-H2AX Foci in Mammalian Fibroblasts at Different Phases of the Cell Cycle. Methods Mol Biol 2017; 1644:187-194. [PMID: 28710765 DOI: 10.1007/978-1-4939-7187-9_17] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
H2AX phosphorylation at Ser139 (formation of γ-H2AX) is an indicator of double-strand breaks in DNA (DSBs) after the action of different genotoxic stresses, including ionizing radiation, environmental agents, and chemotherapy drugs. The sites of DSBs can be visualized as focal sites of γ-H2AX using antibodies and immunofluorescence microscopy. The microscopy technique is the most sensitive method of DSB detection in individual cells. It is useful for experimental research, radiation biodosimetry, and clinical practice. In this chapter, we provide an immunochemical protocol for γ-H2AX labeling and analysis by confocal microscopy. The advantage of the assay is that it enables the quantitation of γ-H2AX foci in individual cells in different phases of the cell cycle.
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Affiliation(s)
- Liudmila Solovjeva
- Institute of Cytology RAS, 4 Tikhoretski Ave., Saint-Petersburg, 194064, Russia
| | - Denis Firsanov
- Institute of Cytology RAS, 4 Tikhoretski Ave., Saint-Petersburg, 194064, Russia
| | - Nadezhda Pleskach
- Institute of Cytology RAS, 4 Tikhoretski Ave., Saint-Petersburg, 194064, Russia
| | - Maria Svetlova
- Institute of Cytology RAS, 4 Tikhoretski Ave., Saint-Petersburg, 194064, Russia.
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14
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Hill MA, O'Neill P, McKenna WG. Comments on potential health effects of MRI-induced DNA lesions: quality is more important to consider than quantity. Eur Heart J Cardiovasc Imaging 2016; 17:1230-1238. [PMID: 27550664 PMCID: PMC5081138 DOI: 10.1093/ehjci/jew163] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Accepted: 07/13/2016] [Indexed: 01/01/2023] Open
Abstract
Magnetic resonance imaging (MRI) is increasingly being used in cardiology to detect heart disease and guide therapy. It is mooted to be a safer alternative to imaging techniques, such as computed tomography (CT) or coronary angiographic imaging. However, there has recently been an increased interest in the potential long-term health risks of MRI, especially in the light of the controversy resulting from a small number of research studies reporting an increase in DNA damage following exposure, with calls to limit its use and avoid unnecessary examination, according to the precautionary principle. Overall the published data are somewhat limited and inconsistent; the ability of MRI to produce DNA lesions has yet to be robustly demonstrated and future experiments should be carefully designed to optimize sensitivity and benchmarked to validate and assess reproducibility. The majority of the current studies have focussed on the initial induction of DNA damage, and this has led to comparisons between the reported induction of γH2AX and implied double-strand break (DSB) yields produced following MRI with induction by imaging techniques using ionizing radiation. However, γH2AX is not only a marker of classical double-ended DSB, but also a marker of stalled replication forks and in certain circumstances stalled DNA transcription. Additionally, ionizing radiation is efficient at producing complex DNA damage, unique to ionizing radiation, with an associated reduction in repairability. Even if the fields associated with MRI are capable of producing DNA damage, the lesions produced will in general be simple, similar to those produced by endogenous processes. It is therefore inappropriate to try and infer cancer risk by simply comparing the yields of γH2AX foci or DNA lesions potentially produced by MRI to those produced by a given exposure of ionizing radiation, which will generally be more biologically effective and have a greater probability of leading to long-term health effects. As a result, it is important to concentrate on more relevant downstream end points (e.g. chromosome aberration production), along with potential mechanisms by which MRI may lead to DNA lesions. This could potentially involve a perturbation in homeostasis of oxidative stress, modifying the background rate of endogenous DNA damage induction. In summary, what the field needs at the moment is more research and less fear mongering.
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Affiliation(s)
- M A Hill
- CRUK/MRC Oxford Institute for Radiation Oncology, University of Oxford, Gray Laboratories, ORCRB Roosevelt Drive, Oxford OX3 7DQ, UK
| | - P O'Neill
- CRUK/MRC Oxford Institute for Radiation Oncology, University of Oxford, Gray Laboratories, ORCRB Roosevelt Drive, Oxford OX3 7DQ, UK
| | - W G McKenna
- CRUK/MRC Oxford Institute for Radiation Oncology, University of Oxford, Gray Laboratories, ORCRB Roosevelt Drive, Oxford OX3 7DQ, UK
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15
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Coucoravas C, Dhanjal S, Henriksson S, Böhm S, Farnebo M. Phosphorylation of the Cajal body protein WRAP53β by ATM promotes its involvement in the DNA damage response. RNA Biol 2016; 14:804-813. [PMID: 27715493 PMCID: PMC5519231 DOI: 10.1080/15476286.2016.1243647] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The cellular response to DNA double-strand breaks is orchestrated by the protein kinase ATM, which phosphorylates key actors in the DNA repair network. WRAP53β is a multifunctional protein that controls trafficking of factors to Cajal bodies, telomeres and DNA double-strand breaks but what regulates the involvement of WRAP53β in these separate processes remains unclear. Here, we show that in response to various types of DNA damage, including IR and UV, WRAP53β is phosphorylated on serine residue 64 by ATM with a time-course that parallels its accumulation at DNA lesions. Interestingly, recruitment of phosphorylated WRAP53β (pWRAP53βS64) to sites of such DNA damage promotes its interaction with γH2AX at these locations. Moreover, pWRAP53βS64 stimulates the accumulation of the repair factor 53BP1 at DNA double-strand breaks and enhances repair of this type of damage via homologous recombination and non-homologous end joining. At the same time, phosphorylation of WRAP53β is dispensable for its localization to Cajal bodies, where it accumulates even in unstressed cells. These findings not only reveal ATM to be an upstream regulator of WRAP53β, but also indicates that phosphorylation of WRAP53β at serine 64 controls its involvement in the DNA damage response and may also restrict its other functions.
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Affiliation(s)
- Christos Coucoravas
- a Department of Oncology-Pathology , Cancer Centrum Karolinska (CCK), Karolinska Institutet , Stockholm , Sweden
| | - Soniya Dhanjal
- a Department of Oncology-Pathology , Cancer Centrum Karolinska (CCK), Karolinska Institutet , Stockholm , Sweden
| | - Sofia Henriksson
- a Department of Oncology-Pathology , Cancer Centrum Karolinska (CCK), Karolinska Institutet , Stockholm , Sweden
| | - Stefanie Böhm
- a Department of Oncology-Pathology , Cancer Centrum Karolinska (CCK), Karolinska Institutet , Stockholm , Sweden
| | - Marianne Farnebo
- a Department of Oncology-Pathology , Cancer Centrum Karolinska (CCK), Karolinska Institutet , Stockholm , Sweden
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16
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Huang Y, Wang X, Niu X, Wang X, Jiang R, Xu T, Liu Y, Liang L, Ou X, Xing X, Li W, Hu C. EZH2 suppresses the nucleotide excision repair in nasopharyngeal carcinoma by silencing XPA gene. Mol Carcinog 2016; 56:447-463. [DOI: 10.1002/mc.22507] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Revised: 05/05/2016] [Accepted: 05/31/2016] [Indexed: 12/24/2022]
Affiliation(s)
- Yuxiang Huang
- Department of Radiation Oncology; Fudan University Shanghai Cancer Center; Shanghai China
| | - Xuanyi Wang
- Institute of Traditional Chinese Medicine and Western Medicine; School of Medicine; Yangzhou University; Yangzhou China
| | - Xiaoshuang Niu
- Department of Radiation Oncology; Fudan University Shanghai Cancer Center; Shanghai China
| | - Xiaoshen Wang
- Department of Radiation Oncology; Fudan University Shanghai Cancer Center; Shanghai China
| | - Rui Jiang
- Department of Radiation Oncology; Fudan University Shanghai Cancer Center; Shanghai China
| | - Tingting Xu
- Department of Radiation Oncology; Fudan University Shanghai Cancer Center; Shanghai China
| | - Yong Liu
- Department of Radiation Oncology; Fudan University Shanghai Cancer Center; Shanghai China
| | - Liping Liang
- Department of Radiation Oncology; Fudan University Shanghai Cancer Center; Shanghai China
| | - Xiaomin Ou
- Department of Radiation Oncology; Fudan University Shanghai Cancer Center; Shanghai China
| | - Xing Xing
- Department of Radiation Oncology; Fudan University Shanghai Cancer Center; Shanghai China
| | - Weiwei Li
- Department of Radiation Oncology; Fudan University Shanghai Cancer Center; Shanghai China
| | - Chaosu Hu
- Department of Radiation Oncology; Fudan University Shanghai Cancer Center; Shanghai China
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17
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Zambrano S, De Toma I, Piffer A, Bianchi ME, Agresti A. NF-κB oscillations translate into functionally related patterns of gene expression. eLife 2016; 5:e09100. [PMID: 26765569 PMCID: PMC4798970 DOI: 10.7554/elife.09100] [Citation(s) in RCA: 101] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Accepted: 01/13/2016] [Indexed: 12/18/2022] Open
Abstract
Several transcription factors (TFs) oscillate, periodically relocating between the cytoplasm and the nucleus. NF-κB, which plays key roles in inflammation and cancer, displays oscillations whose biological advantage remains unclear. Recent work indicated that NF-κB displays sustained oscillations that can be entrained, that is, reach a persistent synchronized state through small periodic perturbations. We show here that for our GFP-p65 knock-in cells NF-κB behaves as a damped oscillator able to synchronize to a variety of periodic external perturbations with no memory. We imposed synchronous dynamics to prove that transcription of NF-κB-controlled genes also oscillates, but mature transcript levels follow three distinct patterns. Two sets of transcripts accumulate fast or slowly, respectively. Another set, comprising chemokine and chemokine receptor mRNAs, oscillates and resets at each new stimulus, with no memory of the past. We propose that TF oscillatory dynamics is a means of segmenting time to provide renewing opportunity windows for decision.
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Affiliation(s)
- Samuel Zambrano
- Division of Genetics and Cell Biology, San Raffaele Scientific Institute, Milan, Italy
- San Raffaele University, Milan, Italy
| | | | | | - Marco E Bianchi
- Division of Genetics and Cell Biology, San Raffaele Scientific Institute, Milan, Italy
- San Raffaele University, Milan, Italy
| | - Alessandra Agresti
- Division of Genetics and Cell Biology, San Raffaele Scientific Institute, Milan, Italy
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18
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Kim E, Davidson LA, Zoh RS, Hensel ME, Patil BS, Jayaprakasha GK, Callaway ES, Allred CD, Turner ND, Weeks BR, Chapkin RS. Homeostatic responses of colonic LGR5+ stem cells following acute in vivo exposure to a genotoxic carcinogen. Carcinogenesis 2015; 37:206-14. [PMID: 26717997 DOI: 10.1093/carcin/bgv250] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Accepted: 11/26/2015] [Indexed: 12/13/2022] Open
Abstract
Perturbations in DNA damage, DNA repair, apoptosis and cell proliferation in the base of the crypt where stem cells reside are associated with colorectal cancer (CRC) initiation and progression. Although the transformation of leucine-rich repeat-containing G protein-coupled receptor 5 (Lgr5)(+) cells is an extremely efficient route towards initiating small intestinal adenomas, the role of Lgr5(+) cells in CRC pathogenesis has not been well investigated. Therefore, we further characterized the properties of colonic Lgr5(+) cells compared to differentiated cells in Lgr5-EGFP-IRES-creER(T2) knock-in mice at the initiation stage of carcinogen azoxymethane (AOM)-induced tumorigenesis using a quantitative immunofluorescence microscopy approach. At 12 and 24h post-AOM treatment, colonic Lgr5(+) stem cells (GFP(high)) were preferentially damaged by carcinogen, exhibiting a 4.7-fold induction of apoptosis compared to differentiated (GFP(neg)) cells. Furthermore, with respect to DNA repair, O(6)-methylguanine DNA methyltransferase (MGMT) expression was preferentially induced (by 18.5-fold) in GFP(high) cells at 24h post-AOM treatment compared to GFP(neg) differentiated cells. This corresponded with a 4.3-fold increase in cell proliferation in GFP(high) cells. These data suggest that Lgr5(+) stem cells uniquely respond to alkylation-induced DNA damage by upregulating DNA damage repair, apoptosis and cell proliferation compared to differentiated cells in order to maintain genomic integrity. These findings highlight the mechanisms by which colonic Lgr5(+) stem cells respond to cancer-causing environmental factors.
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Affiliation(s)
- Eunjoo Kim
- Program in Integrative Nutrition and Complex Diseases, Cellular and Molecular Medicine, Texas A&M Health Science Center
| | - Laurie A Davidson
- Program in Integrative Nutrition and Complex Diseases, Department of Nutrition and Food Science
| | - Roger S Zoh
- Program in Integrative Nutrition and Complex Diseases, Department of Statistics
| | | | - Bhimanagouda S Patil
- Vegetable Crop Improvement Center, Texas A&M University, College Station, TX, USA
| | | | - Evelyn S Callaway
- Program in Integrative Nutrition and Complex Diseases, Department of Nutrition and Food Science
| | | | - Nancy D Turner
- Department of Nutrition and Food Science, Vegetable Crop Improvement Center, Texas A&M University, College Station, TX, USA
| | | | - Robert S Chapkin
- Program in Integrative Nutrition and Complex Diseases, Department of Nutrition and Food Science, Vegetable Crop Improvement Center, Texas A&M University, College Station, TX, USA
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19
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Rothkamm K, Barnard S, Moquet J, Ellender M, Rana Z, Burdak-Rothkamm S. DNA damage foci: Meaning and significance. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2015; 56:491-504. [PMID: 25773265 DOI: 10.1002/em.21944] [Citation(s) in RCA: 237] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Accepted: 02/13/2015] [Indexed: 06/04/2023]
Abstract
The discovery of DNA damage response proteins such as γH2AX, ATM, 53BP1, RAD51, and the MRE11/RAD50/NBS1 complex, that accumulate and/or are modified in the vicinity of a chromosomal DNA double-strand break to form microscopically visible, subnuclear foci, has revolutionized the detection of these lesions and has enabled studies of the cellular machinery that contributes to their repair. Double-strand breaks are induced directly by a number of physical and chemical agents, including ionizing radiation and radiomimetic drugs, but can also arise as secondary lesions during replication and DNA repair following exposure to a wide range of genotoxins. Here we aim to review the biological meaning and significance of DNA damage foci, looking specifically at a range of different settings in which such markers of DNA damage and repair are being studied and interpreted.
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Affiliation(s)
- Kai Rothkamm
- Public Health England, Centre for Radiation, Chemical and Environmental Hazards, Chilton, United Kingdom
- Department of Radiotherapy, Laboratory of Radiation Biology and Experimental Radiation Oncology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Stephen Barnard
- Public Health England, Centre for Radiation, Chemical and Environmental Hazards, Chilton, United Kingdom
| | - Jayne Moquet
- Public Health England, Centre for Radiation, Chemical and Environmental Hazards, Chilton, United Kingdom
| | - Michele Ellender
- Public Health England, Centre for Radiation, Chemical and Environmental Hazards, Chilton, United Kingdom
| | - Zohaib Rana
- Public Health England, Centre for Radiation, Chemical and Environmental Hazards, Chilton, United Kingdom
| | - Susanne Burdak-Rothkamm
- Department of Cellular Pathology, Oxford University Hospitals, Headley Way, Headington, Oxford, United Kingdom
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20
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Bohrer RC, Duggavathi R, Bordignon V. Inhibition of histone deacetylases enhances DNA damage repair in SCNT embryos. Cell Cycle 2014; 13:2138-48. [PMID: 24841373 DOI: 10.4161/cc.29215] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Recent studies have shown that DNA damage affects embryo development and also somatic cell reprogramming into induced pluripotent stem (iPS) cells. It has been also shown that treatment with histone deacetylase inhibitors (HDACi) improves development of embryos produced by somatic cell nuclear transfer (SCNT) and enhances somatic cell reprogramming. There is evidence that increasing histone acetylation at the sites of DNA double-strand breaks (DSBs) is critical for DNA damage repair. Therefore, we hypothesized that HDACi treatment enhances cell programming and embryo development by facilitating DNA damage repair. To test this hypothesis, we first established a DNA damage model wherein exposure of nuclear donor cells to ultraviolet (UV) light prior to nuclear transfer reduced the development of SCNT embryos proportional to the length of UV exposure. Detection of phosphorylated histone H2A.x (H2AX139ph) foci confirmed that exposure of nuclear donor cells to UV light for 10 s was sufficient to increase DSBs in SCNT embryos. Treatment with HDACi during embryo culture increased development and reduced DSBs in SCNT embryos produced from UV-treated cells. Transcript abundance of genes involved in either the homologous recombination (HR) or nonhomologous end-joining (NHEJ) pathways for DSBs repair was reduced by HDACi treatment in developing embryos at day 5 after SCNT. Interestingly, expression of HR and NHEJ genes was similar between HDACi-treated and control SCNT embryos that developed to the blastocyst stage. This suggested that the increased number of embryos that could achieve the blastocyst stage in response to HDACi treatment have repaired DNA damage. These results demonstrate that DNA damage in nuclear donor cells is an important component affecting development of SCNT embryos, and that HDACi treatment after nuclear transfer enhances DSBs repair and development of SCNT embryos.
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Affiliation(s)
| | - Raj Duggavathi
- Department of Animal Science; McGill University; Ste. Anne de Bellevue, Quebec, Canada
| | - Vilceu Bordignon
- Department of Animal Science; McGill University; Ste. Anne de Bellevue, Quebec, Canada
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21
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Ryu S, Kawamura R, Naka R, Silberberg YR, Nakamura N, Nakamura C. Nanoneedle insertion into the cell nucleus does not induce double-strand breaks in chromosomal DNA. J Biosci Bioeng 2013; 116:391-6. [DOI: 10.1016/j.jbiosc.2013.03.022] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2013] [Revised: 03/27/2013] [Accepted: 03/27/2013] [Indexed: 12/30/2022]
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22
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Garcia-Canton C, Anadon A, Meredith C. Assessment of the in vitro γH2AX assay by High Content Screening as a novel genotoxicity test. MUTATION RESEARCH-GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2013; 757:158-66. [PMID: 23988589 DOI: 10.1016/j.mrgentox.2013.08.002] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Revised: 07/07/2013] [Accepted: 08/07/2013] [Indexed: 10/26/2022]
Abstract
The γH2AX assay is widely used as a marker of DNA damage in multiple scientific fields such as cancer biomarker, clinical studies and radiation biology. In particular, the in vitro γH2AX assay has been suggested as a novel in vitro genotoxicity test with potential as a pre-screening tool. However, to date, limited assessments have been carried out to evaluate the sensitivity, specificity and accuracy of the in vitro γH2AX assay. In this study, the microscopy-based system combining automated cellular image acquisition with software quantification for High Content Screening (HCS) has been used for the first time to evaluate the in vitro γH2AX assay. A panel of well-characterised genotoxic and non-genotoxic compounds was selected to assess the performance of the in vitro γH2AX assay in the human bronchial epithelial cell line BEAS-2B. The results obtained during this preliminary assessment indicate that the in vitro γH2AX assay has a high accuracy (86%) as a result of high sensitivity and specificity (86-92% and 80-88% respectively). Our data highlight the potential for γH2AX detection in HCS as a complement to the current regulatory genotoxicity battery of in vitro assays. We therefore recommend more comprehensive assessments to confirm the performance of the in vitro γH2AX assay by HCS with a more extensive set of compounds.
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Affiliation(s)
- Carolina Garcia-Canton
- British American Tobacco, Group Research and Development, Regents Park Road, Southampton, Hampshire SO15 8TL, United Kingdom; Department of Toxicology and Pharmacology, Universidad Complutense de Madrid, Madrid, Spain.
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23
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Scarpato R, Castagna S, Aliotta R, Azzara A, Ghetti F, Filomeni E, Giovannini C, Pirillo C, Testi S, Lombardi S, Tomei A. Kinetics of nuclear phosphorylation ( -H2AX) in human lymphocytes treated in vitro with UVB, bleomycin and mitomycin C. Mutagenesis 2013; 28:465-73. [DOI: 10.1093/mutage/get024] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
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24
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Cameron RS, Liu C, Pihkala JPS. Myosin 16 levels fluctuate during the cell cycle and are downregulated in response to DNA replication stress. Cytoskeleton (Hoboken) 2013; 70:328-48. [PMID: 23596177 DOI: 10.1002/cm.21109] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Accepted: 03/27/2013] [Indexed: 01/03/2023]
Abstract
Myosins comprise a highly conserved superfamily of eukaryotic actin-dependent motor proteins implicated in a large repertoire of functions in both the cytoplasm and the nucleus. Class XVI myosin, MYO16, reveals expression in most somatic as well as meiotic cells with prominent localization in the nucleus, excepting the nucleolus; however, the role(s) of Myo16 in the nucleus remain unknown. In this report, we investigated Myo16 abundance during transit through the cell cycle. Immunolocalization, immunoblot, flow cytometric and quantitative RT-PCR studies performed in Rat2 cells indicate that Myo16 mRNA and protein abundance are cell cycle regulated: in the unperturbed cell cycle, each rises to peak levels in late G1 and thereon through S-phase and each decays as cells enter M-phase. Notably, RNA interference-induced Myo16 depletion results in altered cell cycle distribution as well as in large-scale cell death. In response to DNA replication stress (impaired replication fork progression as a consequence of DNA damage, lack of sufficient deoxynucleotides, or inhibition of DNA polymerases), Myo16 protein shows substantial loss. Attenuation of replication stress (aphidicolin or hydroxyurea) is followed by a recovery of Myo16 expression and resumption of S-phase progression. Collectively, these observations suggest that Myo16 may play a regulatory role in cell cycle progression.
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Affiliation(s)
- Richard S Cameron
- Institute of Molecular Medicine and Genetics, Department of Medicine, Georgia Regents University, Medical College of Georgia, Augusta, Georgia 30912, USA.
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25
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Recruitment of HRDC domain of WRN and BLM to the sites of DNA damage induced by mitomycin C and methyl methanesulfonate. Cell Biol Int 2013; 36:873-81. [PMID: 22657828 DOI: 10.1042/cbi20110510] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
The HRDC (helicase and RNase D C-terminal) domain at the C-terminal of WRNp (Werner protein) (1150-1229 amino acids) and BLMp (Bloom protein) (1212-1292 amino acids) recognize laser microirradiation-induced DNA dsbs (double-strand breaks). However, their role in the recognition of DNA damage other than dsbs has not been reported. In this work, we show that HRDC domain of both the proteins can be recruited to the DNA damage induced by MMS (methyl methanesulfonate) and MMC (methyl mitomycin C). GFP (green fluorescent protein)-tagged HRDC domain produces distinct foci-like respective wild-types after DNA damage induced by the said agents and co-localize with γ-H2AX. However, in time course experiment, we observed that the foci of HRDC domain exist after 24 h of removal of the damaging agents, while the foci of full-length protein disappear completely. This indicates that the repair events are not completed by the presence of protein corresponding to only the HRDC domain. Consequently, cells overexpressing the HRDC domain fail to survive after DNA damage, as determined by MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide] assay. Moreover, 24 h after removal of damaging agents, the extent of DNA damage is greater in cells overexpressing HRDC domain compared with corresponding wild-types, as observed by comet assay. Thus, our observations suggest that HRDC domain of both WRN and BLM can also recognize different types of DNA damages, but for the successful repair they fail to respond to subsequent repair events.
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Vare D, Groth P, Carlsson R, Johansson F, Erixon K, Jenssen D. DNA interstrand crosslinks induce a potent replication block followed by formation and repair of double strand breaks in intact mammalian cells. DNA Repair (Amst) 2012; 11:976-85. [DOI: 10.1016/j.dnarep.2012.09.010] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2012] [Revised: 09/17/2012] [Accepted: 09/19/2012] [Indexed: 11/17/2022]
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Exonuclease 1 (Exo1) is required for activating response to S(N)1 DNA methylating agents. DNA Repair (Amst) 2012; 11:951-64. [PMID: 23062884 DOI: 10.1016/j.dnarep.2012.09.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2012] [Revised: 09/08/2012] [Accepted: 09/11/2012] [Indexed: 11/23/2022]
Abstract
S(N)1 DNA methylating agents are genotoxic agents that methylate numerous nucleophilic centers within DNA including the O(6) position of guanine (O(6)meG). Methylation of this extracyclic oxygen forces mispairing with thymine during DNA replication. The mismatch repair (MMR) system recognizes these O(6)meG:T mispairs and is required to activate DNA damage response (DDR). Exonuclease I (EXO1) is a key component of MMR by resecting the damaged strand; however, whether EXO1 is required to activate MMR-dependent DDR remains unknown. Here we show that knockdown of the mouse ortholog (mExo1) in mouse embryonic fibroblasts (MEFs) results in decreased G2/M checkpoint response, limited effects on cell proliferation, and increased cell viability following exposure to the S(N)1 methylating agent N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), establishing a phenotype paralleling MMR deficiency. MNNG treatment induced formation of γ-H2AX foci with which EXO1 co-localized in MEFs, but mExo1-depleted MEFs displayed a significant diminishment of γ-H2AX foci formation. mExo1 depletion also reduced MSH2 association with DNA duplexes containing G:T mismatches in vitro, decreased MSH2 association with alkylated chromatin in vivo, and abrogated MNNG-induced MSH2/CHK1 interaction. To determine if nuclease activity is required to activate DDR we stably overexpressed a nuclease defective form of human EXO1 (hEXO1) in mExo1-depleted MEFs. These experiments indicated that expression of wildtype and catalytically null hEXO1 was able to restore normal response to MNNG. This study indicates that EXO1 is required to activate MMR-dependent DDR in response to S(N)1 methylating agents; however, this function of EXO1 is independent of its nucleolytic activity.
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Spagnolo L, Barbeau J, Curtin NJ, Morris EP, Pearl LH. Visualization of a DNA-PK/PARP1 complex. Nucleic Acids Res 2012; 40:4168-77. [PMID: 22223246 PMCID: PMC3351162 DOI: 10.1093/nar/gkr1231] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The DNA-dependent protein kinase (DNA-PK) and Poly(ADP-ribose) polymerase-1 (PARP1) are critical enzymes that reduce genomic damage caused by DNA lesions. They are both activated by DNA strand breaks generated by physiological and environmental factors, and they have been shown to interact. Here, we report in vivo evidence that DNA-PK and PARP1 are equally necessary for rapid repair. We purified a DNA-PK/PARP1 complex loaded on DNA and performed electron microscopy and single particle analysis on its tetrameric and dimer-of-tetramers forms. By comparison with the DNA-PK holoenzyme and fitting crystallographic structures, we see that the PARP1 density is in close contact with the Ku subunit. Crucially, PARP1 binding elicits substantial conformational changes in the DNA-PK synaptic dimer assembly. Taken together, our data support a functional, in-pathway role for DNA-PK and PARP1 in double-strand break (DSB) repair. We also propose a NHEJ model where protein-protein interactions alter substantially the architecture of DNA-PK dimers at DSBs, to trigger subsequent interactions or enzymatic reactions.
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Affiliation(s)
- Laura Spagnolo
- Cancer Research UK DNA Repair Enzymes Group, The Institute of Cancer Research, London SW3 6JB, UK.
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Alotaibi A, Baumgartner A, Najafzadeh M, Cemeli E, Anderson D. <i>In Vitro</i> Investigation of DNA Damage Induced by the DNA Cross-Linking Agents Oxaliplatin and Satraplatin in Lymphocytes of Colorectal Cancer Patients. ACTA ACUST UNITED AC 2012. [DOI: 10.4236/jct.2012.31011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Ting HJ, Yasmin-Karim S, Yan SJ, Hsu JW, Lin TH, Zeng W, Messing J, Sheu TJ, Bao BY, Li WX, Messing E, Lee YF. A positive feedback signaling loop between ATM and the vitamin D receptor is critical for cancer chemoprevention by vitamin D. Cancer Res 2011; 72:958-68. [PMID: 22207345 DOI: 10.1158/0008-5472.can-11-0042] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Both epidemiologic and laboratory studies have shown the chemopreventive effects of 1α,25-dihydroxyvitamin D(3) (1,25-VD) in tumorigenesis. However, understanding of the molecular mechanism by which 1,25-VD prevents tumorigenesis remains incomplete. In this study, we used an established mouse model of chemical carcinogenesis to investigate how 1,25-VD prevents malignant transformation. In this model, 1,25-VD promoted expression of the DNA repair genes RAD50 and ATM, both of which are critical for mediating the signaling responses to DNA damage. Correspondingly, 1,25-VD protected cells from genotoxic stress and growth inhibition by promoting double-strand break DNA repair. Depletion of the vitamin D receptor (VDR) reduced these genoprotective effects and drove malignant transformation that could not be prevented by 1,25-VD, defining an essential role for VDR in mediating the anticancer effects of 1,25-VD. Notably, genotoxic stress activated ATM and VDR through phosphorylation of VDR. Mutations in VDR at putative ATM phosphorylation sites impaired the ability of ATM to enhance VDR transactivation activity, diminishing 1,25-VD-mediated induction of ATM and RAD50 expression. Together, our findings identify a novel vitamin D-mediated chemopreventive mechanism involving a positive feedback loop between the DNA repair proteins ATM and VDR.
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Affiliation(s)
- Huei-Ju Ting
- Department of Urology, University of Rochester, Rochester, New York, USA
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Cleaver JE. γH2Ax: biomarker of damage or functional participant in DNA repair "all that glitters is not gold!". Photochem Photobiol 2011; 87:1230-9. [PMID: 21883247 DOI: 10.1111/j.1751-1097.2011.00995.x] [Citation(s) in RCA: 89] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The phosphorylation of H2Ax on its S139 site, γH2Ax, is important for the assembly of repair complexes at DNA double strand breaks (DSBs). The formation and functional role of γH2Ax after other kinds of DNA damage, especially UV light, where DSBs are rare, is less clear. Following UV light in the UVB and UVC ranges, complex distributions of γH2Ax can be identified, quite unlike the discrete enumerable foci seen after ionizing radiation. Several distinct distributions of γH2Ax occur: a low level nuclear-wide distribution of γH2Ax occurs during nucleotide excision repair; irregular focal distributions occur at arrested replication forks; high intensity nuclear-wide γH2Ax occurs in association with S-phase apoptosis. The intensity and distributions of γH2Ax vary according to the activity of excision repair, bypass polymerase and apoptotic caspases. The frequency of DSBs at arrested replication forks is low but highly variable in different cell types, and probably caused by enzymatic action. Despite the prominence of S139 phosphorylation following UV damage, mutation of this site has no influence on the UV damage response indicating that γH2Ax is a biomarker but not a participant in the UV-DNA damage response.
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Affiliation(s)
- James E Cleaver
- Department of Dermatology, University of California, San Francisco, CA, USA.
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Petrillo SK, Desmeules P, Truong TQ, Devine PJ. Detection of DNA damage in oocytes of small ovarian follicles following phosphoramide mustard exposures of cultured rodent ovaries in vitro. Toxicol Appl Pharmacol 2011; 253:94-102. [PMID: 21439308 DOI: 10.1016/j.taap.2011.03.012] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2011] [Revised: 03/01/2011] [Accepted: 03/02/2011] [Indexed: 01/17/2023]
Abstract
Healthy oocytes are critical for producing healthy children, but little is known about whether or not oocytes have the capacity to identify and recover from injury. Using a model ovotoxic alkylating drug, cyclophosphamide (CPA), and its active metabolite, phosphoramide mustard (PM), we previously showed that PM (≥3μM) caused significant follicle loss in postnatal day 4 (PND4) mouse ovaries in vitro. We now investigate whether PM induces DNA damage in oocytes, examining histone H2AX phosphorylation (γH2AX), a marker of DNA double-strand breaks (DSBs). Exposure of cultured PND4 mouse ovaries to 3 and 0.1μM PM induced significant losses of primordial and small primary follicles, respectively. PM-induced γH2AX was observed predominantly in oocytes, in which foci of γH2AX staining increased in a concentration-dependent manner and peaked 18-24h after exposure to 3-10μMPM. Numbers of oocytes with ≥5 γH2AX foci were significantly increased both 1 and 8days after exposure to ≥1μMPM compared to controls. Inhibiting the kinases that phosphorylate H2AX significantly increased follicle loss relative to PM alone. In adult mice, CPA also induced follicle loss in vivo. PM also significantly decreased primordial follicle numbers (≥30μM) and increased γH2AX foci (≥3μM) in cultured PND4 Sprague-Dawley rat ovaries. Results suggest oocytes can detect PM-induced damage at or below concentrations which cause significant follicle loss, and there are quantitative species-specific differences in sensitivity. Surviving oocytes with DNA damage may represent an increased risk for fertility problems or unhealthy offspring.
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Affiliation(s)
- Stephanie K Petrillo
- Université du Québec, Institut national de la recherche scientifique, Institut Armand-Frappier, Laval, QC, Canada
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Hammond-Martel I, Pak H, Yu H, Rouget R, Horwitz AA, Parvin JD, Drobetsky EA, Affar EB. PI 3 kinase related kinases-independent proteolysis of BRCA1 regulates Rad51 recruitment during genotoxic stress in human cells. PLoS One 2010; 5:e14027. [PMID: 21103343 PMCID: PMC2984446 DOI: 10.1371/journal.pone.0014027] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2010] [Accepted: 10/05/2010] [Indexed: 12/17/2022] Open
Abstract
Background The function of BRCA1 in response to ionizing radiation, which directly generates DNA double strand breaks, has been extensively characterized. However previous investigations have produced conflicting data on mutagens that initially induce other classes of DNA adducts. Because of the fundamental and clinical importance of understanding BRCA1 function, we sought to rigorously evaluate the role of this tumor suppressor in response to diverse forms of genotoxic stress. Methodology/Principal Findings We investigated BRCA1 stability and localization in various human cells treated with model mutagens that trigger different DNA damage signaling pathways. We established that, unlike ionizing radiation, either UVC or methylmethanesulfonate (MMS) (generating bulky DNA adducts or alkylated bases respectively) induces a transient downregulation of BRCA1 protein which is neither prevented nor enhanced by inhibition of PIKKs. Moreover, we found that the proteasome mediates early degradation of BRCA1, BARD1, BACH1, and Rad52 implying that critical components of the homologous recombinaion machinery need to be functionally abrogated as part of the early response to UV or MMS. Significantly, we found that inhibition of BRCA1/BARD1 downregulation is accompanied by the unscheduled recruitment of both proteins to chromatin along with Rad51. Consistently, treatment of cells with MMS engendered complete disassembly of Rad51 from pre-formed ionizing radiation-induced foci. Following the initial phase of BRCA1/BARD1 downregulation, we found that the recovery of these proteins in foci coincides with the formation of RPA and Rad51 foci. This indicates that homologous recombination is reactivated at later stage of the cellular response to MMS, most likely to repair DSBs generated by replication blocks. Conclusion/Significance Taken together our results demonstrate that (i) the stabilities of BRCA1/BARD1 complexes are regulated in a mutagen-specific manner, and (ii) indicate the existence of mechanisms that may be required to prevent the simultaneous recruitment of conflicting signaling pathways to sites of DNA damage.
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Affiliation(s)
- Ian Hammond-Martel
- Department of Medicine, Maisonneuve-Rosemont Hospital Research Center, University of Montréal, Montréal, Québec, Canada
| | - Helen Pak
- Department of Medicine, Maisonneuve-Rosemont Hospital Research Center, University of Montréal, Montréal, Québec, Canada
| | - Helen Yu
- Department of Medicine, Maisonneuve-Rosemont Hospital Research Center, University of Montréal, Montréal, Québec, Canada
| | - Raphael Rouget
- Department of Medicine, Maisonneuve-Rosemont Hospital Research Center, University of Montréal, Montréal, Québec, Canada
| | - Andrew A. Horwitz
- Department of Pathology, Harvard Medical School and Brigham and Women's Hospital, Boston, Massachusetts, United States of America
| | - Jeffrey D. Parvin
- Department of Pathology, Harvard Medical School and Brigham and Women's Hospital, Boston, Massachusetts, United States of America
| | - Elliot A. Drobetsky
- Department of Medicine, Maisonneuve-Rosemont Hospital Research Center, University of Montréal, Montréal, Québec, Canada
| | - El Bachir Affar
- Department of Medicine, Maisonneuve-Rosemont Hospital Research Center, University of Montréal, Montréal, Québec, Canada
- * E-mail:
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Zhao H, Traganos F, Darzynkiewicz Z. Kinetics of the UV-induced DNA damage response in relation to cell cycle phase. Correlation with DNA replication. Cytometry A 2010; 77:285-93. [PMID: 20014310 DOI: 10.1002/cyto.a.20839] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
It has been reported that exposure to UV light triggers DNA damage response (DDR) seen as induction of gammaH2AX not only in S- but also in G(1)-phase cells. In the present study, in addition to gammaH2AX, we assessed other markers of DDR, namely phosphorylation of ATM on Ser1981, of ATM/ATR substrate on Ser/Thr at SQ/TQ cluster domains and of the tumor suppressor p53 on Ser15, in human pulmonary carcinoma A549 cells irradiated with 50 J/m(2) of UV-B. Phosphorylation of these proteins detected with phospho-specific Abs and measured by laser scanning cytometry in relation the cell cycle phase was found to be selective to S-phase cells. The kinetics of phosphorylation of ATM was strikingly similar to that of ATM/ATR substrate, peaking at 30 min after UV irradiation and followed by rapid dephosphorylation. The peak of H2AX phosphorylation was seen at 2 h and the peak of p53 phosphorylation at 4 h after exposure to UV light. Local high spatial density of these phospho-proteins reported by intensity of maximal pixel of immunofluorescence in the DDR nuclear foci was distinctly more pronounced in the early compared to late portion of S-phase. Exposure of cells to UV following 1 h pulse-labeling of their DNA with 5-ethynyl-2'deoxyuridine (EdU) made it possible to correlate the extent of DNA replication during the pulse with the extent of the UV-induced H2AX phosphorylation within the same cells. This correlation was very strong (R(2) = 0.98) and the cells that did not incorporate EdU showed no evidence of H2AX phosphorylation. The data are consistent with the mechanism in which stalling of DNA replication forks upon collision with the primary UV-induced DNA lesions and likely formation of double-strand DNA breaks triggers DDR. The prior reports (including our own) on induction of gammaH2AX in G(1) cells by UV may have erroneously identified cells initiating DNA replication following UV exposure as G(1) cells due to the fact that their DNA content did not significantly differ from that of G(1) cells that had not initiated DNA replication.
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Affiliation(s)
- Hong Zhao
- Department of Pathology, Brander Cancer Research Institute, New York Medical College, Valhalla, New York 10595, USA
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Rübe CE, Fricke A, Schneider R, Simon K, Kühne M, Fleckenstein J, Gräber S, Graf N, Rübe C. DNA repair alterations in children with pediatric malignancies: novel opportunities to identify patients at risk for high-grade toxicities. Int J Radiat Oncol Biol Phys 2010; 78:359-69. [PMID: 20153123 DOI: 10.1016/j.ijrobp.2009.08.052] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2009] [Revised: 08/10/2009] [Accepted: 08/10/2009] [Indexed: 12/21/2022]
Abstract
PURPOSE To evaluate, in a pilot study, the phosphorylated H2AX (γH2AX) foci approach for identifying patients with double-strand break (DSB) repair deficiencies, who may overreact to DNA-damaging cancer therapy. METHODS AND MATERIALS The DSB repair capacity of children with solid cancers was analyzed compared with that of age-matched control children and correlated with treatment-related normal-tissue responses (n = 47). Double-strand break repair was investigated by counting γH2AX foci in blood lymphocytes at defined time points after irradiation of blood samples. RESULTS Whereas all healthy control children exhibited proficient DSB repair, 3 children with tumors revealed clearly impaired DSB repair capacities, and 2 of these repair-deficient children developed life-threatening or even lethal normal-tissue toxicities. The underlying mutations affecting regulatory factors involved in DNA repair pathways were identified. Moreover, significant differences in mean DSB repair capacity were observed between children with tumors and control children, suggesting that childhood cancer is based on genetic alterations affecting DSB repair function. CONCLUSIONS Double-strand break repair alteration in children may predispose to cancer formation and may affect children's susceptibility to normal-tissue toxicities. Phosphorylated H2AX analysis of blood samples allows one to detect DSB repair deficiencies and thus enables identification of children at risk for high-grade toxicities.
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Affiliation(s)
- Claudia E Rübe
- Department of Radiation Oncology, Saarland University, Homburg/Saar, Germany.
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