1800MHz射频电磁场对人乳腺癌细胞基因表达的影响

Global gene response to GSM 1800 MHz radiofrequency electromagnetic field in MCF-7 cells

目的了解GSM1800MHz射频电磁场对人乳腺癌细胞株MCF7细胞基因表达谱的影响,筛选射频电磁场的可能反应基因,判断射频电磁场对细胞功能的影响。方法体外传代培养的MCF7细胞分为2组,分别接受GSM1800MHz射频电磁场辐照和假辐照24h,辐照组细胞受比吸收率为2.0W/kg或3.5W/kg的射频电磁场间断辐照(5min开、10min关),辐照结束后,立即抽提细胞总RNA,用基因芯片进行全基因转录组水平分析,芯片实验数据采用MAS5.0软件和DMT3.0软件进行分析。采用定量逆转录聚合酶链反应(RTPCR)验证基因芯片分析筛选到的候选差异表达基因。结果MAS软件分析结果表明,MCF7细胞受辐照后,有少量基因的表达水平发生变化。用DMT软件进行重复性和一致性分析后,在比吸收率为2.0W/kg的射频电磁场辐照组,未找到100%一致变化的差异基因;在比吸收率为3.5W/kg的射频电磁场辐照组,找到5个100%一致变化的候选差异基因,但定量RTPCR结果未能验证基因芯片分析筛选到的差异基因。结论在本实验条件下,未能检测到GSM1800MHz射频电磁场明显影响MCF7细胞的基因表达谱,提示所用的射频电磁场辐照不影响本研究中所用的MCF7细胞功能,或该MCF7细胞对射频电磁场辐照反应性低。

Objective To investigate whether GSM 1800 MHz radiofrequency electromagnetic field （RF EMF） can change the gene expression profile in MCF-7 cells and to screen RF EMF responsive genes. Methods Subcuhured MCF-7 cells were intermittently （5-minute fields on/10-minute fields off） exposed or sham-exposed to GSM 1800 MHz RF EMF, which was modulated by 217 Hz EMF, for 24 hours at an average specific absorption rate （SAR） of 2. 0 W/kg or 3.5 W/kg. Immediately after RF EMF exposure or sham-exposure, total RNA was isolated from MCF-7 cells and then purified. Affymetrix Human Genome U133A Genechip was applied to examine the change of gene expression profile according to the manufacturer＇s instruction. Data was analyzed by Affymetrix Microarray Suite 5.0 （MAS 5. 0） and Affymetrix Data Mining Tool 3.0 （DMT 3. 0）. Quantitative reverse transcription polymerase chain reaction （RT-PCR） was used to validate the differentially expressed genes identified hy Genechip analysis. Results A small number of differential expression genes were found in each comparison after RF EMF exposure. Through reproducible and consistent analysis, no gene or five up-regulated genes were screened out after exposure to RF EMF at SAR of 2. 0 W/kg or 3.5 W/kg, respectively. However, these five genes could not be further confirmed by RT-PCR. Conclusion The present study did not provide clear evidence that RF EMF exposure might distinctly change the gene expression profile in MCF-7 cells under current experimental conditions, implying that the exposure might not affect the MCF-7 cell physiology, or this cell line might be less sensitive to the RF EMF exposure.