scholarly journals Cellular DNA damage by hydrogen peroxide is attenuated by hypotonicity

1994 ◽  
Vol 299 (1) ◽  
pp. 137-140 ◽  
Author(s):  
E A Martins ◽  
R Meneghini
Keyword(s):  
Dna Damage ◽  
Culture Medium ◽  
Cell Clone ◽  
Chinese Hamster ◽  
Fenton Chemistry ◽  
Structural Modifications ◽  
Hypotonic Stress ◽  
Cellular Dna ◽  
Normal Sensitivity ◽  
Phosphate Buffered Saline

Chinese hamster fibroblasts (line V79) withstand well exposure for 30 min to hypotonic medium, corresponding to 25% physiological phosphate-buffered saline (PBS). Under these conditions, the cells become resistant to two effects of H2O2: DNA damage and inhibition of cell clone formation. The normal sensitivity to the DNA-damaging action of H2O2 is restored if, after exposure to hypotonic PBS, the cells are incubated in isotonic cell-culture medium. However, restoration of sensitivity is not observed on incubation in isotonic PBS. The normal sensitivity to H2O2 is also restored if one of the following reducing agents is added to hypotonic PBS: ascorbate, NADH and NADPH, in this order of decreasing efficiency. The recovery of sensitivity to H2O2 by ascorbate is completely inhibited by 1,10-phenanthroline, indicating that ascorbate is mediating the reduction of Fe(III). The decrease in the sensitivity to the DNA-damaging action of H2O2 is not a peculiarity of hypotonic PBS, since it appears to be caused by hypo-osmolarity in general: it is also observed in culture medium of 25% the isotonic concentration, and in 0.07 M sucrose. One explanation for this phenomenon is that hypotonic stress leads to a depletion of reducing species, in particular ascorbate. Under these conditions Fe(II) tends to be oxidized to Fe(III) and the Fenton chemistry is mitigated. However, other possibilities are that hypotonicity brings about structural modifications in the chromatin, rendering it less accessible to H2O2, or that it attenuates the Ca(2+)-activation of endonuclease, induced by oxidative stress.

scholarly journals Targeting Protein-Protein Interactions in the DNA Damage Response Pathways for Cancer Chemotherapy

2021 ◽  
Author(s):  
Kerry Silva McPherson ◽  
Dmitry Korzhnev
Keyword(s):  
Dna Damage ◽  
Dna Damage Response ◽  
Protein Interactions ◽  
Cell Cycle Progression ◽  
Protein Protein Interactions ◽  
Cycle Progression ◽  
Damage Recognition ◽  
Damage Response ◽  
Cellular Dna ◽  
Dna Damage Recognition

Cellular DNA damage response (DDR) is an extensive signaling network that orchestrates DNA damage recognition, repair and avoidance, cell cycle progression and cell death. DDR alternation is a hallmark of...

Production of Recombinant Proteins in Chinese Hamster Ovary Cells Using A Protein-Free Cell Culture Medium

1995 ◽  
Vol 13 (4) ◽  
pp. 389-392 ◽  
Author(s):  
Michael Zang ◽  
Helmut Trautmann ◽  
Christine Gandor ◽  
Ferruccio Messi ◽  
Fred Asselbergs ◽  
...  
Keyword(s):  
Cell Culture ◽  
Recombinant Proteins ◽  
Chinese Hamster Ovary ◽  
Culture Medium ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Free Cell ◽  
Cell Culture Medium ◽  
Ovary Cells

scholarly journals Avian Sarcoma and Leukosis Virus Cytopathic Effect in the Absence of TVB Death Domain Signaling

2005 ◽  
Vol 79 (13) ◽  
pp. 8243-8248 ◽  
Author(s):  
Sara Klucking ◽  
Asha S. Collins ◽  
John A. T. Young
Keyword(s):  
Dna Damage ◽  
Signaling Pathways ◽  
Dna Damage Response ◽  
Cytopathic Effect ◽  
Tumor Necrosis Factor Receptor ◽  
Death Domain ◽  
Trail Receptors ◽  
Damage Response ◽  
Cellular Dna ◽  
Avian Sarcoma

ABSTRACT The cytopathic effect (CPE) seen with some subgroups of avian sarcoma and leukosis virus (ASLV) is associated with viral Env activation of the death-promoting activity of TVB (a tumor necrosis factor receptor-related receptor that is most closely related to mammalian TNF-related apoptosis-inducing ligand [TRAIL] receptors) and with viral superinfection leading to unintegrated viral DNA (UVD) accumulation, which is presumed to activate a cellular DNA damage response. In this study, we employed cells that express signaling-deficient ASLV receptors to demonstrate that an ASLV CPE can be uncoupled from the death-promoting functions of the TVB receptor. However, these cell-killing events were associated with much higher levels of viral superinfection and DNA accumulation than those seen when the virus used signaling-competent TVB receptors. These findings suggest that a putative cellular DNA damage response that is activated by UVD accumulation might act in concert with the death-signaling pathways activated by Env-TVB interactions to trigger cell death. Such a model is consistent with the well-established synergy that exists between TRAIL-signaling pathways and DNA damage responses which is currently being exploited in cancer therapy regimens.

8. Evaluation of Snow Fungus Polysaccharides on benzo[a]pyrene-induced DNA Damage

2018 ◽  
Author(s):  
Daisy Liu
Keyword(s):  
Oxidative Stress ◽  
Dna Damage ◽  
Free Radical ◽  
Radical Scavenging ◽  
Chinese Hamster ◽  
Negative Control ◽  
Lung Fibroblasts ◽  
Protective Effects ◽  
Tremella Fuciformis

Snow fungus, Tremella fuciformis, has been demonstrated to have numerous health benefits including purported chemopreventive properties due to free radical-scavenging ability. Protective effects derived from snow fungus polysaccharides are evaluated on Chinese hamster lung fibroblasts (CCL-39) exposed to carcinogen benzo[a]pyrene known to cause free radical formation and oxidative stress to cells. In this experiment, it was hypothesized that the naturally occurring polysaccharides in snow fungus are able to protect against or reduce oxidative stress-induced DNA damage. Polysaccharides were isolated through an alkaline extraction and in-vitro digestion. DNA damage was measured using the single-cell gel electrophoresis comet assay after exposure to benzo[a]pyrene and polysaccharide extract to lung fibroblasts. Results were calculated using the mean and standard deviation data of tail length and area, respectively. Each damaged cell was measured and analyzed through ImageJ Editing Software. The results indicate a promising trend which depict snow fungus polysaccharides yielding lower levels of DNA damage compared to cells exposed to benzo[a]pyrene and compared to the negative control (phosphate buffered saline and Dulbecco’s cell medium). This study suggests polysaccharides from Tremella fuciformis could truly prevent cellular DNA damage by protecting against oxidative stress.

scholarly journals HPV16-E2 induces prophase arrest and activates the cellular DNA damage response in vitro and in precursor lesions of cervical carcinoma

Oncotarget ◽  
2015 ◽  
Vol 6 (33) ◽  
pp. 34979-34991 ◽  
Author(s):  
Yuezhen Xue ◽  
Shen Yon Toh ◽  
Pingping He ◽  
Thimothy Lim ◽  
Diana Lim ◽  
...  
Keyword(s):  
Dna Damage ◽  
Dna Damage Response ◽  
Cervical Carcinoma ◽  
Precursor Lesions ◽  
Damage Response ◽  
Cellular Dna

scholarly journals Targeted deletion of mouse Rad1 leads to deficient cellular DNA damage responses

2011 ◽  
Vol 2 (5) ◽  
pp. 410-422 ◽  
Author(s):  
Chunbo Zhang ◽  
Yuheng Liu ◽  
Zhishang Hu ◽  
Lili An ◽  
Yikun He ◽  
...  
Keyword(s):  
Dna Damage ◽  
Targeted Deletion ◽  
Dna Damage Responses ◽  
Cellular Dna
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