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Updated: Jul 11, 2026
13:47
Enhanced Reduced Representation Bisulfite Sequencing for Assessment of DNA Methylation at Base Pair Resolution
Published on: February 24, 2015
Radioprotective properties of DNA methylation-disrupting agents.
J F Kalinich1, G N Catravas, S L Snyder
1Radiation Biochemistry Department, Armed Forces Radiobiology Research Institute, NNMC-NCR, Bethesda, MD 20889-5145.
International Journal of Radiation Biology
|May 1, 1991
Summary
5-Azacytidine enhances cell survival against gamma radiation by reducing DNA methylation. This DNA hypomethylation may activate repair enzymes, improving radioprotective effects in V79A03 cells.
Area of Science:
- Molecular Biology
- Radiation Biology
- Epigenetics
Background:
- DNA methylation is a key epigenetic mechanism influencing gene expression.
- Radioprotective agents are crucial for mitigating radiation damage.
- Understanding epigenetic modifications' role in radioresistance is an active research area.
Purpose of the Study:
- To investigate the radioprotective potential of DNA methylation-disrupting agents, 5-azacytidine and sodium butyrate, on V79A03 cells.
- To determine the correlation between DNA methylation status and cellular survival following gamma radiation exposure.
Main Methods:
- V79A03 cells were treated with 5-azacytidine or sodium butyrate.
- DNA methylation levels (5-methylcytosine content) were quantified.
- Cell survival rates after gamma radiation exposure were assessed.
- Dose reduction factor (DRF) was calculated for 5-azacytidine.
Main Results:
- 5-Azacytidine (3 µM, 24h) decreased DNA 5-methylcytosine content by 50% and increased cell survival, yielding a DRF of 1.8.
- Sodium butyrate (1 mM, 24h) increased 5-methylcytosine content by 700% but did not significantly enhance cell survival.
- Both agents induced expression of previously unexpressed genes, such as metallothionein.
Conclusions:
- Hypomethylation of genomic DNA prior to gamma radiation exposure correlates with increased V79A03 cell survival.
- 5-Azacytidine exhibits significant radioprotective properties.
- The observed radioprotection may be linked to the activation of DNA repair mechanisms induced by hypomethylation.
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