极低频电磁场诱导人骨肉瘤细胞凋亡及其机制研究

Extremely low frequency electromagnetic field induces apoptosis of osteosarcoma cells via oxidative stress

目的：探索极低频电磁场对人骨肉瘤细胞增殖凋亡的影响及其分子机制。方法：采用50 Hz、1 mT 的极低频电磁场作用于人骨肉瘤细胞MG－63，通过MTT法检测MG－63细胞的存活率，通过流式细胞术检测MG－63细胞的凋亡率及活性氧水平，并检测 MG－63细胞给予活性氧抑制剂 N－乙酰半胱氨酸（ NAC ）及p38 MAPK抑制剂SB203580作用后细胞凋亡率的变化；通过蛋白质印迹法检测极低频电磁场处理及NAC干预后MG－63细胞p38 MAPK蛋白水平。结果：极低频电磁场能够显著抑制MG－63细胞的存活率，诱导MG－63细胞凋亡及活性氧生成；给予2．5 mmol／L NAC或SB203580干预后MG－63细胞凋亡率显著下降；极低频电磁场处理MG－63细胞后胞内p38 MAPK表达增多，而NAC干预后磷酸化p38 MAPK减少。结论：极低频电磁场可诱导人骨肉瘤细胞MG－63凋亡，其机制可能与活性氧生成增加、p38 MAPK激活有关。

Objective： To investigate the effects of extremely low frequency electromagnetic field （ ELF-EMF ） on human osteosarcoma cells and its mechanisms . Methods：Human osteosarcoma MG-63 cells were exposed to 50 Hz,1 mT ELF-EMF for 1, 2 and 3 h in vitro, with or without pretreatment by reactive oxygen species （ROS） inhibitor N acetylcysteine （ NAC） or p38MAPK inhibitor SB203580.The proliferation of MG-63 cells was determined by MTT method; the apoptosis rate and ROS level in MG-63 cells were detected by flow cytometry .The expression of p38MAPK in MG-63 cells was determined by Western blotting .Results： ELF-EMF decreased the viability of MG-63 cells, inhibited cell growth , induced cell apoptosis and increased the level of ROS significantly .The apoptosis rate declined significantly after treatment with ROS inhibitor NAC or p38MAPK inhibitor SB203580 .After exposure to ELF-EMF, p38 MAPK in MG-63 cells was activated , and the phosphorylation level was also inhibited after treatment with NAC .Conclusion：ELF-EMF can induce the apoptosis of MG-63 cells. Increased ROS and p38MAPK activation may be involved in the mechanism .