Increased γ-H2AX by exposure to a 60-Hz magnetic fields combined with ionizing radiation, but not hydrogen peroxide, in non-tumorigenic human cell lines.
OBJECTIVE
Genotoxic effects have been considered the gold standard to determine if an environmental factor is a carcinogen, but the currently available data for extremely low frequency time-varying magnetic fields (ELF-MF) remain controversial. As an environmental stimulus, the effect of ELF-MF on cellular DNA may be subtle. Therefore, a more sensitive method and systematic research strategy are warranted to evaluate genotoxicity.


METHODS
We investigated the effect of ELF-MF in combination with ionizing radiation (IR) or H(2)O(2) on the DNA damage response of expression of phosphorylated H2AX (γ-H2AX) and production of γ-H2AX foci in non-tumorigenic human cell systems consisting of human lung fibroblast WI-38 cells and human lung epithelial L132 cells.


RESULTS
Exposure to a 60-Hz, 2 mT ELF-MF for 6 h produced increased γ-H2AX expression, as well as γ-H2AX foci production, a common DNA double-strand break (DSB) marker. However, exposure to a 1 mT ELF-MF did not have the same effect. Moreover, 2 mT ELF-MF exposure potentiated the expression of γ-H2AX and γ-H2AX foci production when combined with IR, but not when combined with H(2)O(2).


CONCLUSIONS
ELF-MF could affect the DNA damage response and, in combination with different stimuli, provide different effects on γ-H2AX.
College of Pharmacy, Graduate School of Pharmaceutical Sciences, Ewha Womans University , Seoul , Korea.
Hye Eun
HE
Yoon
Jae Seon
JS
Lee
Sung Ho
SH
Myung
Yun-Sil
YS
Lee
D002478:Cells, Cultured; D004249:DNA Damage; D006657:Histones / Q000378:metabolism*; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D060526:Magnetic Fields; D011839:Radiation, Ionizing; D012854:Sister Chromatid Exchange / Q000528:radiation effects
C468783:H2AX protein, human; D006657:Histones; D006861:Hydrogen Peroxide