Complex repair kinetics of DNA strand breaks induced by γ-rays or UV radiation in Ehrlich ascites tumour cells

Mlejnek, Petr; Kozubek, Stanislav

doi:10.1007/s004110050027

Cited by 4 publications

(3 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For repair incubation periods of 150 min and more a significant reduction of SSB was noted, which the authors interpreted as a prevailing of the synthesis and ligation phase of nucleotide excision repair. For Ehrlich ascites tumor cells the maximum of secondary strand breaks was reported to appear even within 10-20 min after UVC-exposure using an ethidium bromide-based FADU technique (48).…”

Section: Discussionmentioning

confidence: 99%

Fluorometric Analysis of DNA Unwinding (FADU) as a Method for Detecting Repair-induced DNA Strand Breaks in UV-irradiated Mammalian Cells¶

Baumstark‐Khan

Hentschel²,

Nikandrova

et al. 2000

Photochem Photobiol

View full text Add to dashboard Cite

Fluorometric analysis of DNA unwinding (FADU assay) was originally designed to detect X-ray-induced DNA damage in repair-proficient and repair-deficient mammalian cell lines. The method was modified and applied to detect DNA strand breaks in Chinese hamster ovary (CHO) cells exposed to ionizing radiation as well as to UV light. Exposed cells were allowed to repair damaged DNA by incubation for up to 1 h after exposure under standard growth conditions in the presence and in the absence of the DNA synthesis inhibitor aphidicolin. Thereafter, cell lysates were mixed with 0.15 M sodium hydroxide, and DNA unwinding took place at pH 12.1 for 30 min at 20 degrees C. The amount of DNA remaining double-stranded after alkaline reaction was detected by binding to the Hoechst 33258 dye (bisbenzimide) and measuring the fluorescence. After exposure to X-rays DNA strand breaks were observed in all cell lines immediately after exposure with subsequent restitution of high molecular weight DNA during postexposure incubation. In contrast, after UV exposure delayed production of DNA strand break was observed only in cell lines proficient for nucleotide excision repair of DNA photoproducts. Here strand break production was enhanced when the polymerization step was inhibited by adding the repair inhibitor aphidicolin during repair incubation. These results demonstrate that the FADU approach is suitable to distinguish between different DNA lesions (strand breaks versus base alterations) preferentially induced by different environmental radiations (X-rays versus UV) and to distinguish between the different biochemical processes during damage repair (incision versus polymerization and ligation).

show abstract

Section: Discussionmentioning

confidence: 99%

Fluorometric Analysis of DNA Unwinding (FADU) as a Method for Detecting Repair-induced DNA Strand Breaks in UV-irradiated Mammalian Cells¶

Baumstark‐Khan

Hentschel²,

Nikandrova

et al. 2000

Photochem Photobiol

View full text Add to dashboard Cite

show abstract

“…DNA damage was measured by fluorometric analysis of DNA unwinding (the FADU assay), a method originally developed for the rapid detection of DNA strand breaks induced by γ-radiation (9), with slight modifications, as described elsewhere (10). Briefly, aliquots of cell suspension (1-2 × 10 6 cells) were distributed among three sets of test tubes, labelled T, P, and B.…”

Section: Measurement Of Dna Damagementioning

confidence: 99%

Cyclosporin a Potentiates the Cytotoxic Effects of Methyl Methanesulphonate in HL-60 and K562 Cells

2007

View full text Add to dashboard Cite

Methyl methanesulphonate (MMS) is a DNA damaging agent, which induces oxidative stress, ATP depletion, and consequently, cell death, in HL-60 and K562 cells. The cell death induced by MMS predominantly exhibited the morphological and biochemical hallmarks of necrosis. A minor population of dying cells exhibited apoptotic hallmarks, especially in K562 cell cultures. Cyclosporin A (CsA) was used to modulate the MMS-induced cell death. Our results indicated that CsA did not prevent cells from dying, but changed the mode of death from necrotic to apoptotic. Surprisingly, CsA enhanced oxidative stress and increased the overall number of dead cells. Based on these results, we conclude that the modulatory effect of CsA on MMS-induced cell death might arise from an interference by CsA with mitochondrial metabolism, rather than from inhibition of the MMS efflux mediated by P–glycoprotein.

show abstract

“…Therefore, the aim of this study was to test the effect of experimental conditions, such as temperature and light radiation, on chemiluminescence (CL) of lucigenin dissolved in various types of solvent. 0.61 J/m 2 /s [for more details see (5)]. After the irradiation, other lucigenin concentrations (10 −3 -10 −5 mol/L) were prepared by being diluting with test solvents.…”

Section: Introductionmentioning

confidence: 99%

Chemiluminescence of lucigenin is dependent on experimental conditions

Hyršl¹,

Lojek²,

Čı́ž³

et al. 2004

Luminescence

View full text Add to dashboard Cite

The aim of the study was to test the effect of experimental conditions such as light radiation and temperature on chemiluminescence (CL) of 10(-2)-10(-5) mol/L lucigenin dissolved in various types of solvents. Irradiation by UV light (280, 297, 313 or 400 nm) induced a significant increase in CL of lucigenin dissolved in borate buffer. This effect was the most obvious for 10(-2)-10(-3) mol/L lucigenin. All wavelengths used had a similar effect. UV irradiation did not induce changes in the CL activity of lucigenin dissolved in dH2O or in dimethyl sulphoxide (DMSO). Different results for various solvents were not dependent on pH. The CL activity of 10(-2) mol/L and 10(-3) mol/L lucigenin dissolved in borate buffer increased depending on the solution temperature (25 degrees C, 30 degrees C, 37 degrees C or 40 degrees C) already at the beginning of the analysis, with a further increase during 16 h incubation period. It can be summarized that temperatures higher than 25 degrees C and intensive light irradiation are among those factors which significantly affect the result of analysis when lucigenin is used as a luminophor.

show abstract

Complex repair kinetics of DNA strand breaks induced by γ-rays or UV radiation in Ehrlich ascites tumour cells

Cited by 4 publications

References 20 publications

Fluorometric Analysis of DNA Unwinding (FADU) as a Method for Detecting Repair-induced DNA Strand Breaks in UV-irradiated Mammalian Cells¶

Fluorometric Analysis of DNA Unwinding (FADU) as a Method for Detecting Repair-induced DNA Strand Breaks in UV-irradiated Mammalian Cells¶

Cyclosporin a Potentiates the Cytotoxic Effects of Methyl Methanesulphonate in HL-60 and K562 Cells

Chemiluminescence of lucigenin is dependent on experimental conditions

Contact Info

Product

Resources

About