Mahmoudinasab Hamideh, Sanie-Jahromi Fatemeh, Saadat Mostafa
Department of Biology, College of Sciences, Shiraz University, Shiraz 71467-13565, Iran.
Mol Biol Res Commun. 2016 Jun;5(2):77-85.
In the past three decades, study on the biological effects of extremely low-frequency electromagnetic fields (ELF-EMFs) has been of interest to scientists. Although the exact mechanism of its effect is not fully understood, free radical processes has been proposed as a possible mechanism. This study was designed to evaluate the effect of 50-Hz EMFs on the mRNA levels of seven antioxidant genes (, , , , , , and ) in human MCF-7 cells. The EMF exposure patterns were: 1) 5 min field-on/5 min filed-off, 2) 15 min field-on/15 min field-off, 3) 30 min field-on continuously. In all three exposure conditions we tried to have total exposure time of 30 minutes. Control cultures were located in the exposure apparatus when the power was off. The experiments were done at two field intensities; 0.25 mT and 0.50 mT. The RNA extraction was done at two times; immediately post exposure and two hours post exposure. The mRNA levels were determined using quantitative real-time polymerase chain reaction. MTT assay for three exposure conditions in the two field intensities represented no cytotoxic effect on MCF-7 cells. Statistical comparison showed a significant difference between 0.25 mT and 0.50 mT intensities for "the 15 min field-on/15 min field-off condition" (Fisher's exact test, P=0.041), indicating that at 0.50 mT intensity field, the number of down-regulated and/or up-regulated genes increased compared with the other ones. However, there is no statistical significant difference between the field intensities for the two others EMF exposure conditions.
在过去三十年中，极低频电磁场（ELF-EMFs）的生物学效应研究一直是科学家们感兴趣的课题。尽管其确切作用机制尚未完全明了，但自由基过程被认为是一种可能的机制。本研究旨在评估50赫兹电磁场对人MCF-7细胞中七个抗氧化基因（、、、、、和）mRNA水平的影响。电磁场暴露模式为：1）5分钟开场/5分钟关场；2）15分钟开场/15分钟关场；3）30分钟持续开场。在所有三种暴露条件下，我们试图使总暴露时间为30分钟。对照培养物在电源关闭时置于暴露装置中。实验在两种场强下进行，分别为0.25毫特斯拉和0.50毫特斯拉。RNA提取在两个时间点进行，暴露后立即和暴露后两小时。使用定量实时聚合酶链反应测定mRNA水平。在两种场强下对三种暴露条件进行的MTT分析表明，对MCF-7细胞无细胞毒性作用。统计比较显示，在“15分钟开场/15分钟关场条件”下，0.25毫特斯拉和0.50毫特斯拉场强之间存在显著差异（Fisher精确检验，P = 0.041），这表明在0.50毫特斯拉场强下，与其他场强相比，下调和/或上调基因的数量增加。然而，在其他两种电磁场暴露条件下，场强之间没有统计学上的显著差异。
