Wang Xiaoya, Liu Chuan, Ma Qinglong, Feng Wei, Yang Lingling, Lu Yonghui, Zhou Zhou, Yu Zhengping, Li Wei, Zhang Lei
Cell Physiol Biochem. 2015;37(3):1075-88. doi: 10.1159/000430233. Epub 2015 Sep 25.
BACKGROUND/AIMS: The purpose of this study was to explore the in vitro putative genotoxicity during exposure of Neuro-2a cells to radiofrequency electromagnetic fields (RF-EMFs) with or without silencing of 8-oxoG DNA glycosylase-1 (OGG1).
Neuro-2a cells treated with or without OGG1 siRNA were exposed to 900 MHz Global System for Mobile Communication (GSM) Talk signals continuously at a specific absorption rate (SAR) of 0, 0.5, 1 or 2 W/kg for 24 h. DNA strand breakage and DNA base damage were measured by the alkaline comet assay and a modified comet assay using formamidopyrimidine DNA glycosylase (FPG), respectively. Reactive oxygen species (ROS) levels and cell viability were monitored using the non-fluorescent probe 2, 7-dichlorofluorescein diacetate (DCFH-DA) and CCK-8 assay.
Exposure to 900 MHz RF-EMFs with insufficient energy could induce oxidative DNA base damage in Neuro-2a cells. These increases were concomitant with similar increases in the generation of reactive oxygen species (ROS). Without OGG1 siRNA, 2 W/kg RF-EMFs induced oxidative DNA base damage in Neuro-2a cells. Interestingly, with OGG1 siRNA, RF-EMFs could cause DNA base damage in Neuro-2a cells as low as 1 W/kg. However, neither DNA strand breakage nor altered cell viability was observed.
Even if further studies remain conducted we support the hypothesis that OGG1 is involved in the process of DNA base repair and may play a pivotal role in protecting DNA bases from RF-EMF induced oxidative damage.
背景/目的：本研究旨在探讨神经母细胞瘤细胞（Neuro-2a细胞）暴露于射频电磁场（RF-EMF）时，无论8-氧代鸟嘌呤DNA糖基化酶1（OGG1）是否沉默，其体外潜在的遗传毒性。
用或不用OGG1小干扰RNA（siRNA）处理Neuro-2a细胞，然后以0、0.5、1或2W/kg的比吸收率（SAR）连续暴露于900MHz全球移动通信系统（GSM）通话信号24小时。分别通过碱性彗星试验和使用甲酰胺嘧啶DNA糖基化酶（FPG）的改良彗星试验来检测DNA链断裂和DNA碱基损伤。使用非荧光探针2,7-二氯荧光素二乙酸酯（DCFH-DA）和CCK-8试验监测活性氧（ROS）水平和细胞活力。
暴露于能量不足的900MHz RF-EMF可诱导Neuro-2a细胞发生氧化性DNA碱基损伤。这些损伤的增加与活性氧生成的类似增加同时出现。在没有OGG1 siRNA的情况下，2W/kg的RF-EMF可诱导Neuro-2a细胞发生氧化性DNA碱基损伤。有趣的是，在有OGG1 siRNA的情况下，低至1W/kg的RF-EMF就能导致Neuro-2a细胞发生DNA碱基损伤。然而，未观察到DNA链断裂或细胞活力改变。
即使仍需进一步研究，我们也支持这样的假设，即OGG1参与DNA碱基修复过程，并且可能在保护DNA碱基免受RF-EMF诱导的氧化损伤中起关键作用。
