scholarly journals Differentiation-Induced Radioresistance in Muscle Cells

2004 ◽  
Vol 24 (14) ◽  
pp. 6350-6361 ◽  
Author(s):  
Lucia Latella ◽  
Jiri Lukas ◽  
Cristiano Simone ◽  
Pier Lorenzo Puri ◽  
Jiri Bartek
Keyword(s):  
Cell Cycle ◽  
Dna Damage ◽  
Dna Double Strand Breaks ◽  
Proliferating Cells ◽  
Histone H2ax ◽  
Selective Blockade ◽  
Differentiated Cells ◽  
Dna Damage Signaling ◽  
Ataxia Teleangiectasia ◽  
Associated Proteins

ABSTRACT DNA damage induces cell cycle arrest and DNA repair or apoptosis in proliferating cells. Terminally differentiated cells are permanently withdrawn from the cell cycle and partly resistant to apoptosis. To investigate the effects of genotoxic agents in postmitotic cells, we compared DNA damage-activated responses in mouse and human proliferating myoblasts and their differentiated counterparts, the myotubes. DNA double-strand breaks caused by ionizing radiation (IR) induced rapid activating autophosphorylation of ataxia-teleangiectasia-mutated (ATM), phosphorylation of histone H2AX, recruitment of repair-associated proteins MRE11 and Nbs1, and activation of Chk2 in both myoblasts and myotubes. However, IR-activated, ATM-mediated phosphorylation of p53 at serine 15 (human) or 18 (mouse) [Ser15(h)/18(m)], and apoptosis occurred in myoblasts but was impaired in myotubes. This phosphorylation could be enforced in myotubes by the anthracycline derivative doxorubicin, leading to selective activation of proapoptotic genes. Unexpectedly, the abundance of autophosphorylated ATM was indistinguishable after exposure of myotubes to IR (10 Gy) or doxorubicin (1 μM/24 h) despite efficient phosphorylation of p53 Ser15(h)/18(m), and apoptosis occurred only in response to doxorubicin. These results suggest that radioresistance in myotubes might reflect a differentiation-associated, pathway-selective blockade of DNA damage signaling downstream of ATM. This mechanism appears to preserve IR-induced activation of the ATM-H2AX-MRE11/Rad50/Nbs1 lesion processing and repair pathway yet restrain ATM-p53-mediated apoptosis, thereby contributing to life-long maintenance of differentiated muscle tissues.

scholarly journals DNA damage signaling in response to double-strand breaks during mitosis

2010 ◽  
Vol 190 (2) ◽  
pp. 197-207 ◽  
Author(s):  
Simona Giunta ◽  
Rimma Belotserkovskaya ◽  
Stephen P. Jackson
Keyword(s):  
Dna Damage ◽  
Mitotic Cell ◽  
Double Strand Breaks ◽  
Dna Double Strand Breaks ◽  
Strand Breaks ◽  
Histone H2ax ◽  
Mrn Complex ◽  
Dna Damage Signaling ◽  
Dependent Protein ◽  
Mitotic Cells

The signaling cascade initiated in response to DNA double-strand breaks (DSBs) has been extensively investigated in interphase cells. Here, we show that mitotic cells treated with DSB-inducing agents activate a “primary” DNA damage response (DDR) comprised of early signaling events, including activation of the protein kinases ataxia telangiectasia mutated (ATM) and DNA-dependent protein kinase (DNA-PK), histone H2AX phosphorylation together with recruitment of mediator of DNA damage checkpoint 1 (MDC1), and the Mre11–Rad50–Nbs1 (MRN) complex to damage sites. However, mitotic cells display no detectable recruitment of the E3 ubiquitin ligases RNF8 and RNF168, or accumulation of 53BP1 and BRCA1, at DSB sites. Accordingly, we found that DNA-damage signaling is attenuated in mitotic cells, with full DDR activation only ensuing when a DSB-containing mitotic cell enters G1. Finally, we present data suggesting that induction of a primary DDR in mitosis is important because transient inactivation of ATM and DNA-PK renders mitotic cells hypersensitive to DSB-inducing agents.

Lack of Effect of RuvB-Like Proteins on DNA Damage Signaling Activation

2010 ◽  
Vol 65 (1-2) ◽  
pp. 148-152
Author(s):  
Anastas Gospodinov ◽  
Boyka Anachkova
Keyword(s):  
Cell Cycle ◽  
Dna Damage ◽  
Cellular Response ◽  
Cell Cycle Distribution ◽  
Ataxia Telangiectasia Mutated ◽  
Atm Kinase ◽  
Strand Breaks ◽  
Histone H2ax ◽  
Dna Damage Signaling ◽  
Signaling Activation

Ataxia telangiectasia mutated (ATM) kinase is a central player in cellular response to DNA damage. Phosphorylation of the histone H2AX by ATM is required for the accumulation of repair proteins at the sites of double-strand breaks. Recently, it was reported that the histone acetyltransferase Tat interactive protein-60 (TIP60) is required to acetylate ATM prior to its activation. The RuvB-like proteins TIP48 and TIP49 are known to be necessary for the assembly and functional activity of the TIP60 acetyltransferase complex. In the present communication, we investigated the requirements of TIP48 and TIP49 for ATM activation by monitoring the cell cycle distribution and H2AX phosphorylation after irradiation of TIP48- and TIP49-depleted cells. We found that neither the cell cycle nor γ-H2AX were affected in TIP48- and TIP49-silenced cells, suggesting that the TIP60 chromatin modifi cation complex is not engaged in DNA damage signaling upstream of ATM.

scholarly journals DNA double-strand break repair: a theoretical framework and its application

2016 ◽  
Vol 13 (114) ◽  
pp. 20150679 ◽  
Author(s):  
Philip J. Murray ◽  
Bart Cornelissen ◽  
Katherine A. Vallis ◽  
S. Jon Chapman
Keyword(s):  
Dna Damage ◽  
Auger Electron ◽  
Strand Break ◽  
Dna Double Strand Breaks ◽  
Dsb Repair ◽  
Histone H2ax ◽  
Dna Double Strand Break ◽  
A Cell

DNA double-strand breaks (DSBs) are formed as a result of genotoxic insults, such as exogenous ionizing radiation, and are among the most serious types of DNA damage. One of the earliest molecular responses following DSB formation is the phosphorylation of the histone H2AX, giving rise to γ H2AX. Many copies of γ H2AX are generated at DSBs and can be detected in vitro as foci using well-established immuno-histochemical methods. It has previously been shown that anti- γ H2AX antibodies, modified by the addition of the cell-penetrating peptide TAT and a fluorescent or radionuclide label, can be used to visualize and quantify DSBs in vivo . Moreover, when labelled with a high amount of the short-range, Auger electron-emitting radioisotope, 111 In, the amount of DNA damage within a cell can be increased, leading to cell death. In this report, we develop a mathematical model that describes how molecular processes at individual sites of DNA damage give rise to quantifiable foci. Equations that describe stochastic mean behaviours at individual DSB sites are derived and parametrized using population-scale, time-series measurements from two different cancer cell lines. The model is used to examine two case studies in which the introduction of an antibody (anti- γ H2AX-TAT) that targets a key component in the DSB repair pathway influences system behaviour. We investigate: (i) how the interaction between anti- γ H2AX-TAT and γ H2AX effects the kinetics of H2AX phosphorylation and DSB repair and (ii) model behaviour when the anti- γ H2AX antibody is labelled with Auger electron-emitting 111 In and can thus instigate additional DNA damage. This work supports the conclusion that DSB kinetics are largely unaffected by the introduction of the anti- γ H2AX antibody, a result that has been validated experimentally, and hence the hypothesis that the use of anti- γ H2AX antibody to quantify DSBs does not violate the image tracer principle. Moreover, it provides a novel model of DNA damage accumulation in the presence of Auger electron-emitting 111 In that is supported qualitatively by the available experimental data.

Cell cycle control and DNA-damage signaling in mammals

2021 ◽  
pp. 237-255
Author(s):  
R. Gundogdu ◽  
A. Hergovich ◽  
V. Gómez
Keyword(s):  
Cell Cycle ◽  
Dna Damage ◽  
Cell Cycle Control ◽  
Dna Damage Signaling

scholarly journals MDC1 PST-repeat region promotes histone H2AX-independent chromatin association and DNA damage tolerance

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Israel Salguero ◽  
Rimma Belotserkovskaya ◽  
Julia Coates ◽  
Matylda Sczaniecka-Clift ◽  
Mukerrem Demir ◽  
...  
Keyword(s):  
Dna Damage ◽  
Double Strand Breaks ◽  
Repeat Region ◽  
Independent Function ◽  
Dna Double Strand Breaks ◽  
Dna Damage Tolerance ◽  
Strand Breaks ◽  
Histone H2ax ◽  
Independent Association ◽  
Dna Damage Signalling

AbstractHistone H2AX and MDC1 are key DNA repair and DNA-damage signalling proteins. When DNA double-strand breaks (DSBs) occur, H2AX is phosphorylated and then recruits MDC1, which in turn serves as a docking platform to promote the localization of other factors, including 53BP1, to DSB sites. Here, by using CRISPR-Cas9 engineered human cell lines, we identify a hitherto unknown, H2AX-independent, function of MDC1 mediated by its PST-repeat region. We show that the PST-repeat region directly interacts with chromatin via the nucleosome acidic patch and mediates DNA damage-independent association of MDC1 with chromatin. We find that this region is largely functionally dispensable when the canonical γH2AX-MDC1 pathway is operative but becomes critical for 53BP1 recruitment to DNA-damage sites and cell survival following DSB induction when H2AX is not available. Consequently, our results suggest a role for MDC1 in activating the DDR in areas of the genome lacking or depleted of H2AX.

scholarly journals Giant cell glioblastoma is a distinctive subtype of glioma characterized by vulnerability to DNA damage

2019 ◽  
Vol 37 (1) ◽  
pp. 5-13 ◽  
Author(s):  
Kaoru Ogawa ◽  
Akira Kurose ◽  
Akihisa Kamataki ◽  
Kenichiro Asano ◽  
Kosuke Katayama ◽  
...  
Keyword(s):  
Dna Damage ◽  
Giant Cell ◽  
Small Cells ◽  
Wild Type ◽  
Dna Double Strand Breaks ◽  
Proliferating Cells ◽  
Strand Breaks ◽  
Mitotic Slippage ◽  
Minimal Invasion ◽  
Giant Cell Glioblastoma

Abstract Giant cell glioblastoma (GC-GBM) consists of large cells with pleomorphic nuclei. As a contrast to GC-GBM, we defined monotonous small GBM (MS-GBM) as GBM that consists of small cells with monotonous small nuclei, and compared the DNA damage as well as other pathological features. GC-GBM showed minimal invasion (< 2 mm) and focal sarcomatous areas. TERTp was wild type in GC-GBM but mutant in MS-GBM. OLIG2 expression was significantly higher in MS-GBM (P < 0.01) (77% in MS-GBM and 7% in GC-GBM). GC-GBM showed significantly higher DNA double-strand breaks (DSBs) compared with MS-GBM (P < 0.01) (76% in GC-GBM and 15% in MS-GBM). Nearly, all large cells in GC-GBM underwent DSBs. Thus, significant DSBs in GC-GBM might be induced by an innate lesser stemness characteristic and be followed by mitotic slippage, resulting in polyploidization and the large pleomorphic nuclei. We conclude that GC-GBM is a distinctive subtype of glioma characterized by its vulnerability to DNA damage and that wild-type TERTp and lower OLIG2 function might induce this feature. Notably, even large pleomorphic nuclei with severe DSBs demonstrated Ki67 positivity, which alerts pathologists to the interpretation of Ki67 positivity, because cells with large nuclei undergoing severe DSBs cannot be recognized as proliferating cells that contribute to tumor aggressiveness.

Loss Of NIPA Leads To Defects In The Repair Of DNA Double Strand Breaks In Mice

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 2488-2488
Author(s):  
Anna Lena Illert ◽  
Cristina Antinozzi ◽  
Hiroyuki Kawaguchi ◽  
Michal Kulinski ◽  
Christine Klitzing ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Dna Damage ◽  
Meiotic Prophase ◽  
Conflicts Of Interest ◽  
Cyclin B1 ◽  
Double Strand Breaks ◽  
Conditional Knockout ◽  
Dna Double Strand Breaks ◽  
Strand Breaks ◽  
Chromosome Axis

Abstract Regulated oscillation of protein expression is an essential mechanism of cell cycle control. The SCF class of E3 ubiquitin ligases is involved in this process by targeting cell cycle regulatory proteins for degradation by the proteasome. We previously reported the cloning of NIPA (Nuclear Interaction Partner of ALK) in complex with constitutively active oncogenic fusions of ALK, which contributes to the development of lymphomas and sarcomas. Subsequently we characterized NIPA as a F-Box protein that defines an oscillating ubiquitin E3 ligase targeting nuclear cyclin B1 in interphase thus contributing to the timing of mitotic entry. Using a conditional knockout strategy we inactivated the gene encoding Nipa. Nipa-deficient animals are viable, but show a lower birth rate and a reduced body weight. Furthermore, Nipa-deficient males were sterile due to a block of spermatogenesis during meiotic prophase. Virtually no spermatocytes progress beyond a late-zygotene to early-pachytene stage and reach an aberrant stage, with synaptonemal complex disassembly and incomplete synapsis. Nipa-/- females are sub-fertile with an early and severe meiotic defect during embryogenesis with extensive apoptosis in early prophase (E13.5-E14.5). Here we report, that Nipa-/- meiocytes exhibit persistent cytological markers for DNA double strand break repair proteins (like DMC1, RAD51) in meiotic prophase with more than twice as many DMC1 foci as control animals. Kinetic analysis of the first wave of spermatogenesis showed increased DMC1/RAD51 foci in Nipa-/- cells as soon as early-pachynema cells appear (13-14 days post partum). Moreover, we show that Nipa deficiency does not lead to a defect in meiotic sex chromosome inactivation despite epithelial stage IV apoptosis. Nipa-deficient spermatocytes exhibit numerous abnormalities in staining of chromosome axis associated proteins (like SYCP3 and STAG3) indicating that chromosome axis defects were associated with compromised chromosome axis integrity leading to overt chromosome fragmentation. Further in vitro analyses with bleomycin treated MEFs displayed high pH2AX levels in cells lacking NIPA. Repair of DNA DSB seemed to be abolished in these cells as the pH2AX-level were sustained and still visible after 90 min of timecourse, where wildtype cells already repaired sides of DNA Damage. Consistent with these findings NIPA-deficient spleen cells showed compromised DNA Damage repair measured in a comet assay with a significantly longer olive tail moment in NIPA knockout cells under repair conditions. Taken together, the phenotype of Nipa-knockout mice is a definitive proof of the meiotic significance of NIPA and our results show a new, unsuspected role of NIPA in chromosome stability and the repair of DNA double strand breaks. Disclosures: No relevant conflicts of interest to declare.

scholarly journals The chromatin-remodeling factor CHD4 coordinates signaling and repair after DNA damage

2010 ◽  
Vol 190 (5) ◽  
pp. 731-740 ◽  
Author(s):  
Dorthe Helena Larsen ◽  
Catherine Poinsignon ◽  
Thorkell Gudjonsson ◽  
Christoffel Dinant ◽  
Mark R. Payne ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Dna Damage ◽  
Dna Repair ◽  
Chromatin Remodeling ◽  
Cell Cycle Progression ◽  
Clonogenic Survival ◽  
Dna Double Strand Breaks ◽  
Checkpoint Signaling ◽  
Strand Breaks ◽  
Delay Cell

In response to ionizing radiation (IR), cells delay cell cycle progression and activate DNA repair. Both processes are vital for genome integrity, but the mechanisms involved in their coordination are not fully understood. In a mass spectrometry screen, we identified the adenosine triphosphate–dependent chromatin-remodeling protein CHD4 (chromodomain helicase DNA-binding protein 4) as a factor that becomes transiently immobilized on chromatin after IR. Knockdown of CHD4 triggers enhanced Cdc25A degradation and p21Cip1 accumulation, which lead to more pronounced cyclin-dependent kinase inhibition and extended cell cycle delay. At DNA double-strand breaks, depletion of CHD4 disrupts the chromatin response at the level of the RNF168 ubiquitin ligase, which in turn impairs local ubiquitylation and BRCA1 assembly. These cell cycle and chromatin defects are accompanied by elevated spontaneous and IR-induced DNA breakage, reduced efficiency of DNA repair, and decreased clonogenic survival. Thus, CHD4 emerges as a novel genome caretaker and a factor that facilitates both checkpoint signaling and repair events after DNA damage.

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