scholarly journals AID and Reactive Oxygen Species Can Induce DNA Breaks within Human Chromosomal Translocation Fragile Zones

2019 ◽  
Vol 73 (3) ◽  
pp. 639
Author(s):  
Nicholas R. Pannunzio ◽  
Michael R. Lieber
Keyword(s):  
Reactive Oxygen Species ◽  
Chromosomal Translocation ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Dna Breaks

scholarly journals MYC Can Induce DNA Breaks In vivo and In vitro Independent of Reactive Oxygen Species

2006 ◽  
Vol 66 (13) ◽  
pp. 6598-6605 ◽  
Author(s):  
Suma Ray ◽  
Kondala R. Atkuri ◽  
Debabrita Deb-Basu ◽  
Adam S. Adler ◽  
Howard Y. Chang ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Dna Breaks

scholarly journals Site-specific targeting of a light activated dCas9-KIllerRed fusion protein generates transient, localized regions of oxidative DNA damage

2020 ◽  
Author(s):  
Nealia C.M. House ◽  
Jacob V. Layer ◽  
Brendan D. Price
Keyword(s):  
Reactive Oxygen Species ◽  
Dna Damage ◽  
Oxidative Dna Damage ◽  
Light Exposure ◽  
Green Light ◽  
Reactive Oxygen ◽  
Dna Lesions ◽  
Oxygen Species ◽  
Dna Breaks ◽  
Site Specific

AbstractDNA repair requires reorganization of the local chromatin structure to facilitate access to and repair of the DNA. Studying DNA double-strand break (DSB) repair in specific chromatin domains has been aided by the use of sequence-specific endonucleases to generate targeted breaks. Here, we describe a new approach that combines KillerRed, a photosensitizer that generates reactive oxygen species (ROS) when exposed to light, and the genome-targeting properties of the CRISPR/Cas9 system. Fusing KillerRed to catalytically inactive Cas9 (dCas9) generates dCas9-KR, which can then be targeted to any desired genomic region with an appropriate guide RNA. Activation of dCas9-KR with green light generates a local increase in reactive oxygen species, resulting in “clustered” oxidative damage, including both DNA breaks and base damage. Activation of dCas9-KR rapidly (within minutes) increases both γH2AX and recruitment of the KU70/80 complex. Importantly, this damage is repaired within 10 minutes of termination of light exposure, indicating that the DNA damage generated by dCas9-KR is both rapid and transient. Further, repair is carried out exclusively through NHEJ, with no detectable contribution from HR-based mechanisms. Surprisingly, sequencing of repaired DNA damage regions did not reveal any increase in either mutations or INDELs in the targeted region, implying that NHEJ has high fidelity under the conditions of low level, limited damage. The dCas9-KR approach for creating targeted damage has significant advantages over the use of endonucleases, since the duration and intensity of DNA damage can be controlled in “real time” by controlling light exposure. In addition, unlike endonucleases that carry out multiple cut-repair cycles, dCas9-KR produces a single burst of damage, more closely resembling the type of damage experienced during acute exposure to reactive oxygen species or environmental toxins. dCas9-KR is a promising system to induce DNA damage and measure site-specific repair kinetics at clustered DNA lesions.

scholarly journals Metformin in combination with JS-K inhibits growth of renal cell carcinoma cells via reactive oxygen species activation and inducing DNA breaks

2020 ◽  
Vol 11 (13) ◽  
pp. 3701-3712
Author(s):  
Yuwan Zhao ◽  
Qiuming Luo ◽  
Jierong Mo ◽  
Jianwei Li ◽  
Dongcai Ye ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Renal Cell Carcinoma ◽  
Cell Carcinoma ◽  
Renal Cell ◽  
Reactive Oxygen ◽  
Carcinoma Cells ◽  
Oxygen Species ◽  
Dna Breaks

scholarly journals Reactive oxygen species in BCR-ABL1-expressing cells – relevance to chronic myeloid leukemia

2016 ◽  
Vol 64 (1) ◽  
Author(s):  
Joanna Antoszewska-Smith ◽  
Elzbieta Pawlowska ◽  
Janusz Błasiak
Keyword(s):  
Reactive Oxygen Species ◽  
Chronic Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Kinase Inhibitors ◽  
Continuous Production ◽  
Chromosomal Translocation ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Tki Resistance ◽  
Stem And Progenitor Cells

Chronic myeloid leukemia (CML) results from the t(9;22) reciprocal chromosomal translocation producing the BCR-ABL1 gene, conferring growth and proliferation advantages in the CML cells.  CML progresses from chronic, often syndrome-free, to blast phase, fatal if not treated. Although the involvement of BCR-ABL1 in some signaling pathways is considered as the cause of CML, the mechanisms resulting in its progression are not completely known. However, BCR-ABL1 stimulates the production of reactive oxygen species (ROS), which levels increase with CML progression and induce BCR-ABL1 self-mutagenesis. Introducing imatinib and other tyrosine kinase inhibitors (TKIs) to CML therapy radically improved its outcome, but TKIs-resistance became an emerging problem. TKI-resistance can be associated with even higher ROS production than in TKI-sensitive cells. Therefore, ROS-induced self-mutagenesis of BCR-ABL1 can be crucial for CML progression and TKI resistance and in this way should be taken into account in therapeutic strategies. As a continuous production of ROS by BCR-ABL1 would lead to its self-destruction and death of CML cells, there must be mechanisms controlling this phenomenon. These can be dependent on DNA repair, which is modulated by BCR-ABL1 and can be different in CML stem and progenitor cells. Altogether, the mechanisms of the involvement of BCR-ABL1 in ROS signaling can be involved in CML progression and TKI-resistance and warrant further study.

scholarly journals Hepatitis C Virus Triggers Mitochondrial Permeability Transition with Production of Reactive Oxygen Species, Leading to DNA Damage and STAT3 Activation

2006 ◽  
Vol 80 (14) ◽  
pp. 7199-7207 ◽  
Author(s):  
Keigo Machida ◽  
Kevin T.-H. Cheng ◽  
Chao-Kuen Lai ◽  
King-Song Jeng ◽  
Vicky M.-H. Sung ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Dna Damage ◽  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Reactive Oxygen ◽  
Mitochondrial Damage ◽  
Hcv Infection ◽  
Oxygen Species ◽  
Dna Breaks ◽  
Infected Cells

ABSTRACT Hepatitis C virus (HCV) infection is frequently associated with the development of hepatocellular carcinomas and non-Hodgkin's B-cell lymphomas. Previously, we reported that HCV infection causes cellular DNA damage and mutations, which are mediated by nitric oxide (NO). NO often damages mitochondria, leading to induction of double-stranded DNA breaks (DSBs) and accumulation of oxidative DNA damage. Here we report that HCV infection causes production of reactive oxygen species (ROS) and lowering of mitochondrial transmembrane potential (ΔΨm) in in vitro HCV-infected cell cultures. The changes in membrane potential could be inhibited by BCL-2. Furthermore, an inhibitor of ROS production, antioxidant N-acetyl-l-cysteine (NAC), or an inhibitor of NO, 1400W, prevented the alterations of ΔΨm. The HCV-induced DSB was also abolished by a combination of NO and ROS inhibitors. These results indicated that the mitochondrial damage and DSBs in HCV-infected cells were mediated by both NO and ROS. Among the HCV proteins, core, E1, and NS3 are potent ROS inducers: their expression led to DNA damage and activation of STAT3. Correspondingly, core-protein-transgenic mice showed elevated levels of lipid peroxidation and oxidatively damaged DNA. These HCV studies thus identified ROS, along with the previously identified NO, as the primary inducers of DSBs and mitochondrial damage in HCV-infected cells.

scholarly journals Az oxidatív stressz szerepe szívelégtelenségben

2015 ◽  
Vol 156 (47) ◽  
pp. 1916-1920 ◽  
Author(s):  
Roland Gál ◽  
Róbert Halmosi
Keyword(s):  
Reactive Oxygen Species ◽  
Vascular System ◽  
Reactive Oxygen ◽  
Mitochondrial Respiratory Chain ◽  
Cell Types ◽  
Oxygen Species ◽  
Cytochrome P450 Enzymes ◽  
Dna Breaks ◽  
Hypertrophic Growth ◽  
Myocardium Remodeling

Oxidative stress plays an important role in the development of heart failure. Reactive oxygen and nitrogen species can be generated in all cell types that can be found in the myocardium. Potential sources of reactive oxygen species are the NADPH oxidases, nitric oxide synthase, lipoxygenases, cyclooxygenase, xanthine oxidase, cytochrome P450 enzymes, and the mitochondrial respiratory chain. The reactive oxygen species mediated damages are implicated in both the vascular system (endothelial dysfunction, atherosclerosis) and the myocardium (remodeling). Oixidative stress causes lipid and protein oixidation as well as single stranded DNA breaks and induces changes in signaling pathways which serve as central transducers of cardiac hypertrophic growth, remodeling and/or ventricular dilatation. Orv. Hetil., 2015, 156(47), 1916–1920.

scholarly journals Reactive oxygen species play a dominant role in all pathways of rapid quinolone-mediated killing

2019 ◽  
Vol 75 (3) ◽  
pp. 576-585 ◽  
Author(s):  
Yuzhi Hong ◽  
Qiming Li ◽  
Qiong Gao ◽  
Jianping Xie ◽  
Haihui Huang ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Dominant Role ◽  
Reactive Oxygen ◽  
Dna Lesions ◽  
Dominant Factor ◽  
Oxygen Species ◽  
Protective Effects ◽  
Dna Breaks ◽  
E Coli ◽  
Ros Accumulation

Abstract Background Quinolones have been thought to rapidly kill bacteria in two ways: (i) quinolone-topoisomerase-DNA lesions stimulate the accumulation of toxic reactive oxygen species (ROS); and (ii) the lesions directly cause lethal DNA breaks. Traditional killing assays may have underestimated the ROS contribution by overlooking the possibility that ROS continue to accumulate and kill cells on drug-free agar after quinolone removal. Methods Quinolone-induced, ROS-mediated killing of Escherichia coli was measured by plating post-treatment samples on agar with/without anti-ROS agents. Results When E. coli cultures were treated with ciprofloxacin or moxifloxacin in the presence of chloramphenicol (to accentuate DNA-break-mediated killing), lethal activity, revealed by plating on quinolone-free agar, was inhibited by supplementing agar with ROS-mitigating agents. Moreover, norfloxacin-mediated lethality, observed with cells suspended in saline, was blocked by inhibitors of ROS accumulation and exacerbated by a katG catalase deficiency that impairs peroxide detoxification. Unlike WT cells, the katG mutant was killed by nalidixic acid or norfloxacin with chloramphenicol present and by nalidixic or oxolinic acid with cells suspended in saline. ROS accumulated after quinolone removal with cultures either co-treated with chloramphenicol or suspended in saline. Deficiencies in recA or recB reduced the protective effects of ROS-mitigating agents, supporting the idea that repair of quinolone-mediated DNA lesions suppresses the direct lethal effects of such lesions. Conclusions ROS are the dominant factor in all modes of quinolone-mediated lethality, as quinolone-mediated primary DNA lesions are insufficient to kill without triggering ROS accumulation. ROS-stimulating adjuvants may enhance the lethality of quinolones and perhaps other antimicrobials.

scholarly journals Site-specific targeting of a light activated dCas9-KillerRed fusion protein generates transient, localized regions of oxidative DNA damage

PLoS ONE ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. e0237759
Author(s):  
Nealia C. M. House ◽  
Ramya Parasuram ◽  
Jacob V. Layer ◽  
Brendan D. Price
Keyword(s):  
Reactive Oxygen Species ◽  
Dna Damage ◽  
Oxidative Dna Damage ◽  
Light Exposure ◽  
Green Light ◽  
Reactive Oxygen ◽  
Dna Lesions ◽  
Oxygen Species ◽  
Dna Breaks ◽  
Site Specific

DNA repair requires reorganization of the local chromatin structure to facilitate access to and repair of the DNA. Studying DNA double-strand break (DSB) repair in specific chromatin domains has been aided by the use of sequence-specific endonucleases to generate targeted breaks. Here, we describe a new approach that combines KillerRed, a photosensitizer that generates reactive oxygen species (ROS) when exposed to light, and the genome-targeting properties of the CRISPR/Cas9 system. Fusing KillerRed to catalytically inactive Cas9 (dCas9) generates dCas9-KR, which can then be targeted to any desired genomic region with an appropriate guide RNA. Activation of dCas9-KR with green light generates a local increase in reactive oxygen species, resulting in “clustered” oxidative damage, including both DNA breaks and base damage. Activation of dCas9-KR rapidly (within minutes) increases both γH2AX and recruitment of the KU70/80 complex. Importantly, this damage is repaired within 10 minutes of termination of light exposure, indicating that the DNA damage generated by dCas9-KR is both rapid and transient. Further, repair is carried out exclusively through NHEJ, with no detectable contribution from HR-based mechanisms. Surprisingly, sequencing of repaired DNA damage regions did not reveal any increase in either mutations or INDELs in the targeted region, implying that NHEJ has high fidelity under the conditions of low level, limited damage. The dCas9-KR approach for creating targeted damage has significant advantages over the use of endonucleases, since the duration and intensity of DNA damage can be controlled in “real time” by controlling light exposure. In addition, unlike endonucleases that carry out multiple cut-repair cycles, dCas9-KR produces a single burst of damage, more closely resembling the type of damage experienced during acute exposure to reactive oxygen species or environmental toxins. dCas9-KR is a promising system to induce DNA damage and measure site-specific repair kinetics at clustered DNA lesions.

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