scholarly journals Increased activity of poly(ADP-ribose)-polymerase in PML-depleted cells - novel perspectives for cancer therapy

2013 ◽  
Vol 94 (1) ◽  
pp. 75-79
Author(s):  
S V Boichuk ◽  
B R Ramazanov ◽  
I G Mustafin ◽  
Gjoerup O
Keyword(s):  
Dna Damage ◽  
Ionizing Radiation ◽  
Genotoxic Stress ◽  
Dna Double Strand Breaks ◽  
Compensatory Response ◽  
Strand Breaks ◽  
Fetal Bovine ◽  
Parp Activity ◽  
The Relationship ◽  
Increased Activity

Aim. To investigate the relationship between PML expression and poly(ADP-ribose)-polymerase (PARP) activity in physiological conditions and at genotoxic stress induced by chemotherapy and ionizing radiation. Methods. The study was conducted on BJ fibroblasts cultured in DMEM/199 medium supplemented with fetal bovine serum, L-glutamine and antibiotics. PML down-regulation was achieved by short interfering ribonucleic acid transfection. To induce deoxyribonucleic acid (DNA) damage in BJ fibroblasts, doxorubicin and hydroxyurea or ionizing radiation were used. PARP activity, formation of DNA double-strand breaks and DNA damage response were examined by Western blotting and immunofluorescence microscopy. Results. PML knockdown was accomplished with an increased PARP activity, confirmed by an increased expression of poly-ADP-ribose (PAR) polymers. At PML knockdown ant DNA damage caused by chemotherapy and ionizing radiation, there is a significant increase in PAR polymers expression as well as increase in the number of cells containing PAR foci. Conclusion. Increased activity of poly(ADP-ribose)-polymerase at PML knockdown and DNA damaging conditions indicates the compensatory response due to insufficiency of the homologous recombination mechanisms. The phenomenon found widens the spectrum of malignancies that might be potentially sensitive to the therapy with poly(ADP-ribose)-polymerase inhibitors.

scholarly journals βarrestin-1 regulates DNA repair by acting as an E3-ubiquitin ligase adaptor for 53BP1

2019 ◽  
Vol 27 (4) ◽  
pp. 1200-1213 ◽  
Author(s):  
Ainhoa Nieto ◽  
Makoto R. Hara ◽  
Victor Quereda ◽  
Wayne Grant ◽  
Vanessa Saunders ◽  
...  
Keyword(s):  
Dna Damage ◽  
Ionizing Radiation ◽  
Ubiquitin Ligase ◽  
E3 Ubiquitin Ligase ◽  
Strand Break ◽  
Double Strand Breaks ◽  
Dna Double Strand Breaks ◽  
Molecular Scaffold ◽  
Strand Breaks

Abstract Cellular DNA is constantly under threat from internal and external insults, consequently multiple pathways have evolved to maintain chromosomal fidelity. Our previous studies revealed that chronic stress, mediated by continuous stimulation of the β2-adrenergic-βarrestin-1 signaling axis suppresses activity of the tumor suppressor p53 and impairs genomic integrity. In this pathway, βarrestin-1 (βarr1) acts as a molecular scaffold to promote the binding and degradation of p53 by the E3-ubiquitin ligase, MDM2. We sought to determine whether βarr1 plays additional roles in the repair of DNA damage. Here we demonstrate that in mice βarr1 interacts with p53-binding protein 1 (53BP1) with major consequences for the repair of DNA double-strand breaks. 53BP1 is a principle component of the DNA damage response, and when recruited to the site of double-strand breaks in DNA, 53BP1 plays an important role coordinating repair of these toxic lesions. Here, we report that βarr1 directs 53BP1 degradation by acting as a scaffold for the E3-ubiquitin ligase Rad18. Consequently, knockdown of βarr1 stabilizes 53BP1 augmenting the number of 53BP1 DNA damage repair foci following exposure to ionizing radiation. Accordingly, βarr1 loss leads to a marked increase in irradiation resistance both in cells and in vivo. Thus, βarr1 is an important regulator of double strand break repair, and disruption of the βarr1/53BP1 interaction offers an attractive strategy to protect cells against high levels of exposure to ionizing radiation.

scholarly journals DNA damage induces nuclear actin filament assembly by Formin-2 and Spire-1/2 that promotes efficient DNA repair

eLife ◽  
2015 ◽  
Vol 4 ◽  
Author(s):  
Brittany J Belin ◽  
Terri Lee ◽  
R Dyche Mullins
Keyword(s):  
Dna Damage ◽  
Dna Repair ◽  
Actin Filaments ◽  
Protein Misfolding ◽  
Molecular Mechanisms ◽  
Genotoxic Stress ◽  
Nuclear Actin ◽  
Dna Double Strand Breaks ◽  
Strand Breaks ◽  
Serum Stimulation

Actin filaments assemble inside the nucleus in response to multiple cellular perturbations, including heat shock, protein misfolding, integrin engagement, and serum stimulation. We find that DNA damage also generates nuclear actin filaments—detectable by phalloidin and live-cell actin probes—with three characteristic morphologies: (i) long, nucleoplasmic filaments; (ii) short, nucleolus-associated filaments; and (iii) dense, nucleoplasmic clusters. This DNA damage-induced nuclear actin assembly requires two biologically and physically linked nucleation factors: Formin-2 and Spire-1/Spire-2. Formin-2 accumulates in the nucleus after DNA damage, and depletion of either Formin-2 or actin's nuclear import factor, importin-9, increases the number of DNA double-strand breaks (DSBs), linking nuclear actin filaments to efficient DSB clearance. Nuclear actin filaments are also required for nuclear oxidation induced by acute genotoxic stress. Our results reveal a previously unknown role for nuclear actin filaments in DNA repair and identify the molecular mechanisms creating these nuclear filaments.

scholarly journals Automodified Poly(ADP-Ribose) Polymerase Analysis to monitor DNA Damage in Peripheral Lymphocytes of Floricoltorists occupationally exposed to Pesticides

2019 ◽  
Author(s):  
Serena Imperato ◽  
Carmela Mistretta ◽  
Maria Marone ◽  
Ilaria Migliaccio ◽  
Ilaria Pulcinelli ◽  
...  
Keyword(s):  
Dna Damage ◽  
Genotoxic Stress ◽  
Polymerase Activity ◽  
Peripheral Blood Lymphocytes ◽  
Activity Levels ◽  
Strand Breaks ◽  
Non Invasive ◽  
Occupationally Exposed ◽  
Parp Activity ◽  
Dna Strand

Background: Increased DNA damage and the propension to cancer development, depend on the modulation of the mechanisms to control and maintain genomic integrity. Poly(ADP-Ribose)Polymerase activation and automodification are early responses to genotoxic stress. Upon binding to DNA strand breaks, the enzyme, a molecular DNA nick sensor, is hyperactivated: this is the first step in a series of events leading to either DNA repair or apoptosis. Enzyme hyperactivation and automodification can be easily measured and are widely used to look at DNA damage extent in the cell. We investigated whether these two markers (increased catalytic activity and auto modification), could help to monitor DNA damage in lymphocytes of flower growers from Southern Italy, occupationally exposed to pesticides. Methods: Peripheral lymphocyte lysates were analysed for Poly(ADP-Ribose) Polymerase activity, and by SDS-PAGE and anti-Poly(ADP-Ribose)Polymerase 1-antibody to measure automodified anti-Poly(ADP-Ribose) Polymerase levels by densitometry. Results: Poly(ADP-Ribose)Polymerase activity levels were consistent with those of enzyme auto-modification. Growers daily exposed to pesticides, showed both biomarkers very high, either in the presence or in the absence of pathologies. Conclusions: PARP activity and auto-modification in peripheral blood lymphocytes are possible,non-invasive, and routinar tools to monitor the healthy conditions of floricoltorists.

scholarly journals Oocytes can efficiently repair DNA double-strand breaks to restore genetic integrity and protect offspring health

2020 ◽  
Vol 117 (21) ◽  
pp. 11513-11522 ◽  
Author(s):  
Jessica M. Stringer ◽  
Amy Winship ◽  
Nadeen Zerafa ◽  
Matthew Wakefield ◽  
Karla Hutt
Keyword(s):  
Dna Damage ◽  
Dna Repair ◽  
Germ Line ◽  
Genotoxic Stress ◽  
Double Strand Breaks ◽  
Genetic Integrity ◽  
Dna Double Strand Breaks ◽  
Γ Irradiation ◽  
Strand Breaks ◽  
Offspring Health

Female fertility and offspring health are critically dependent on an adequate supply of high-quality oocytes, the majority of which are maintained in the ovaries in a unique state of meiotic prophase arrest. While mechanisms of DNA repair during meiotic recombination are well characterized, the same is not true for prophase-arrested oocytes. Here we show that prophase-arrested oocytes rapidly respond to γ-irradiation–induced DNA double-strand breaks by activating Ataxia Telangiectasia Mutated, phosphorylating histone H2AX, and localizing RAD51 to the sites of DNA damage. Despite mobilizing the DNA repair response, even very low levels of DNA damage result in the apoptosis of prophase-arrested oocytes. However, we show that, when apoptosis is inhibited, severe DNA damage is corrected via homologous recombination repair. The repair is sufficient to support fertility and maintain health and genetic fidelity in offspring. Thus, despite the preferential induction of apoptosis following exogenously induced genotoxic stress, prophase-arrested oocytes are highly capable of functionally efficient DNA repair. These data implicate DNA repair as a key quality control mechanism in the female germ line and a critical determinant of fertility and genetic integrity.

scholarly journals Automodified Poly(ADP-Ribose) Polymerase Analysisto Monitor DNA Damagein Peripheral Lymphocytes of Floriculturists Occupationally Exposed to Pesticides

Cells ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 137 ◽  
Author(s):  
Serena Imperato ◽  
Carmela Mistretta ◽  
Maria Marone ◽  
Ilaria Migliaccio ◽  
Ilaria Pulcinelli ◽  
...  
Keyword(s):  
Dna Damage ◽  
Genotoxic Stress ◽  
Polymerase Activity ◽  
Peripheral Blood Lymphocytes ◽  
Strand Breaks ◽  
Non Invasive ◽  
Sds Page ◽  
Occupationally Exposed ◽  
Parp Activity ◽  
Dna Strand

Increased DNA damage and the propension to cancer development, depend on the modulation of the mechanisms to control and maintain genomic integrity. Poly(ADP-Ribose)Polymerase activation and automodification are early responses to genotoxic stress. Upon binding to DNA strand breaks, the enzyme, a molecular DNA nick sensor, is hyperactivated: this is the first step in a series of events leading to either DNA repair or apoptosis. Enzyme hyperactivation and automodification can be easily measured and are widely used to look at DNA damage extent in the cell. We investigated whether these two markers (increased catalytic activity and auto modification), could help to monitor DNA damage in lymphocytes of flower growers from Southern Italy, occupationally exposed to pesticides. Peripheral lymphocyte lysates were analyzed for Poly(ADP-Ribose)Polymerase activity, and by SDS-PAGE and anti-Poly(ADP-Ribose)Polymerase 1-antibodyto measure automodified Poly(ADP-Ribose)Polymerase levels bydensitometry. Poly(ADP-Ribose)Polymerase activity and PARP automodification followed the same trend. Growers daily exposed to pesticides, showed both biomarkers very high, either in the presence or in the absence of pathologies. PARP activity and auto-modification in peripheral blood lymphocytes are possible, non-invasive, androutinartools to monitor the healthy conditions of floricoltorists.

scholarly journals Analysis of Residual DSBs in Ataxia-Telangiectasia Lymphoblast Cells Initiating Apoptosis

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Teresa Anglada ◽  
Mariona Terradas ◽  
Laia Hernández ◽  
Anna Genescà ◽  
Marta Martín
Keyword(s):  
Dna Damage ◽  
Ataxia Telangiectasia ◽  
Dna Double Strand Breaks ◽  
Predictive Tool ◽  
Normal Cells ◽  
Strand Breaks ◽  
Radiation Induced ◽  
Late Apoptosis ◽  
Induced Apoptosis ◽  
The Relationship

In order to examine the relationship between accumulation of residual DNA double-strand breaks (DSBs) and cell death, we have used a control and an ATM (Ataxia-Telangiectasia Mutated) defective cell line, as Ataxia-Telangiectasia (AT) cells tend to accumulate residual DSBs at long times after damage infliction. After irradiation, AT cells showed checkpoint impairment and a fraction of cells displayed an abnormal centrosome number and tetraploid DNA content, and this fraction increased along with apoptosis rates. At all times analyzed, AT cells displayed a significantly higher rate of radiation-induced apoptosis than normal cells. Besides apoptosis, 70–85% of the AT viable cells (TUNEL-negative) carried ≥10γH2AX foci/cell, while only 12–27% of normal cells did. The fraction of AT and normal cells undergoing early and late apoptosis were isolated by flow cytometry and residual DSBs were concretely scored in these populations. Half of theγH2AX-positive AT cells undergoing early apoptosis carried ≥10γH2AX foci/cell and this fraction increased to 75% in late apoptosis. The results suggest that retention of DNA damage-inducedγH2AX foci is an indicative of lethal DNA damage, as cells undergoing apoptosis are those accumulating more DSBs. Scoring of residualγH2AX foci might function as a predictive tool to assess radiation-induced apoptosis.

Effects of melatonin on repair of DNA double strand breaks caused by ionizing radiation in rat peripheral blood

2016 ◽  
Vol 9 (4) ◽  
pp. 821-827 ◽  
Author(s):  
Majid Valizadeh ◽  
Alireza Shirazi ◽  
Pantea Izadi ◽  
Javad Tavakkoli Bazzaz ◽  
Hamed Rezaeejam ◽  
...  
Keyword(s):  
Ionizing Radiation ◽  
Peripheral Blood ◽  
Double Strand Breaks ◽  
Dna Double Strand Breaks ◽  
Strand Breaks

scholarly journals PARP1 exhibits enhanced association and catalytic efficiency with γH2A.X-nucleosome

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Deepti Sharma ◽  
Louis De Falco ◽  
Sivaraman Padavattan ◽  
Chang Rao ◽  
Susana Geifman-Shochat ◽  
...  
Keyword(s):  
Dna Damage ◽  
Mutational Analysis ◽  
Catalytic Efficiency ◽  
Double Strand Breaks ◽  
Genomic Integrity ◽  
Dna Double Strand Breaks ◽  
Strand Breaks ◽  
Nucleosome Core ◽  
Epigenetic Marker ◽  
Kinetics Of

AbstractThe poly(ADP-ribose) polymerase, PARP1, plays a key role in maintaining genomic integrity by detecting DNA damage and mediating repair. γH2A.X is the primary histone marker for DNA double-strand breaks and PARP1 localizes to H2A.X-enriched chromatin damage sites, but the basis for this association is not clear. We characterize the kinetics of PARP1 binding to a variety of nucleosomes harbouring DNA double-strand breaks, which reveal that PARP1 associates faster with (γ)H2A.X- versus H2A-nucleosomes, resulting in a higher affinity for the former, which is maximal for γH2A.X-nucleosome that is also the activator eliciting the greatest poly-ADP-ribosylation catalytic efficiency. The enhanced activities with γH2A.X-nucleosome coincide with increased accessibility of the DNA termini resulting from the H2A.X-Ser139 phosphorylation. Indeed, H2A- and (γ)H2A.X-nucleosomes have distinct stability characteristics, which are rationalized by mutational analysis and (γ)H2A.X-nucleosome core crystal structures. This suggests that the γH2A.X epigenetic marker directly facilitates DNA repair by stabilizing PARP1 association and promoting catalysis.

scholarly journals RepID-deficient cancer cells are sensitized to a drug targeting p97/VCP segregase

2021 ◽  
Author(s):  
Sang-Min Jang ◽  
Christophe E. Redon ◽  
Haiqing Fu ◽  
Fred E. Indig ◽  
Mirit I. Aladjem
Keyword(s):  
Dna Damage ◽  
Cancer Cells ◽  
Cell Sorting ◽  
Clonogenic Survival ◽  
Double Strand Breaks ◽  
Dna Double Strand Breaks ◽  
Strand Breaks ◽  
Ubiquitinated Proteins ◽  
Damage Response ◽  
Survival Assay

Abstract Background The p97/valosin-containing protein (VCP) complex is a crucial factor for the segregation of ubiquitinated proteins in the DNA damage response and repair pathway. Objective We investigated whether blocking the p97/VCP function can inhibit the proliferation of RepID-deficient cancer cells using immunofluorescence, clonogenic survival assay, fluorescence-activated cell sorting, and immunoblotting. Result p97/VCP was recruited to chromatin and colocalized with DNA double-strand breaks in RepID-deficient cancer cells that undergo spontaneous DNA damage. Inhibition of p97/VCP induced death of RepID-depleted cancer cells. This study highlights the potential of targeting p97/VCP complex as an anticancer therapeutic approach. Conclusion Our results show that RepID is required to prevent excessive DNA damage at the endogenous levels. Localization of p97/VCP to DSB sites was induced based on spontaneous DNA damage in RepID-depleted cancer cells. Anticancer drugs targeting p97/VCP may be highly potent in RepID-deficient cells. Therefore, we suggest that p97/VCP inhibitors synergize with RepID depletion to kill cancer cells.

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