Electromagnetic noise inhibits radiofrequency radiation-induced DNA damage and reactive oxygen species increase in human lens epithelial cells.
OBJECTIVE
The goal of this study was to investigate whether superposing of electromagnetic noise could block or attenuate DNA damage and intracellular reactive oxygen species (ROS) increase of cultured human lens epithelial cells (HLECs) induced by acute exposure to 1.8 GHz radiofrequency field (RF) of the Global System for Mobile Communications (GSM).


METHODS
An sXc-1800 RF exposure system was used to produce a GSM signal at 1.8 GHz (217 Hz amplitude-modulated) with the specific absorption rate (SAR) of 1, 2, 3, and 4 W/kg. After 2 h of intermittent exposure, the ROS level was assessed by the fluorescent probe, 2',7'-dichlorodihydrofluorescein diacetate (DCFH-DA). DNA damage to HLECs was examined by alkaline comet assay and the phosphorylated form of histone variant H2AX (gammaH2AX) foci formation assay.


RESULTS
After exposure to 1.8 GHz RF for 2 h, HLECs exhibited significant intracellular ROS increase in the 2, 3, and 4 W/kg groups. RF radiation at the SAR of 3 W/kg and 4 W/kg could induce significant DNA damage, examined by alkaline comet assay, which was used to detect mainly single strand breaks (SSBs), while no statistical difference in double strand breaks (DSBs), evaluated by gammaH2AX foci, was found between RF exposure (SAR: 3 and 4 W/kg) and sham exposure groups. When RF was superposed with 2 muT electromagnetic noise could block RF-induced ROS increase and DNA damage.


CONCLUSIONS
DNA damage induced by 1.8 GHz radiofrequency field for 2 h, which was mainly SSBs, may be associated with the increased ROS production. Electromagnetic noise could block RF-induced ROS formation and DNA damage.
Yao
Ke
K
Eye Center, Affiliated Second Hospital, College of Medicine, Zhejiang University, Hangzhou,China. xlren@zju.edu.cn
Wu
Wei
W
Wang
KaiJun
K
Ni
Shuang
S
Ye
PanPan
P
Yu
YiBo
Y
Ye
Juan
J
Sun
LiXia
L
D002478:Cells, Cultured; D020552:Comet Assay; D053903:DNA Breaks, Double-Stranded / Q000528:radiation effects; D004249:DNA Damage; D055590:Electromagnetic Phenomena; D004847:Epithelial Cells / Q000166:cytology / Q000378:metabolism / Q000528:radiation effects*; D006657:Histones / Q000378:metabolism; D006801:Humans; D007908:Lens, Crystalline / Q000166:cytology* / Q000528:radiation effects*; D008872:Microwaves; D011846:Radio Waves; D017382:Reactive Oxygen Species / Q000378:metabolism*
C468783:H2AX protein, human; D006657:Histones; D017382:Reactive Oxygen Species