Extremely Low Frequency Electromagnetic Field Induces Apoptosis Of Osteosarcoma Cells Via Oxidative Stress

Objective:To explore the effects of Extremely Low Frequency Electromagnetic Field (ELF-EMF) on the growth of the human osteosarcoma cells, and the mechanisms involved in this process.Methods:The effects of 50Hz,1mT ELF-EMF on the osteosarcoma cell line MG-63, MNNG-HOS C1 were determined by MTT assay. Flow cytometry was used to detect the apoptosis rate and reactive oxygen species(ROS) of the osteosarcoma cell lines, which were exposed to the 50Hz,1mT ELF-EMF with or without ROS inhibitor N acetylcysteine(NAC) and p38 MAPK inhibitors SB203580at different time points. Western blot analyses were performed to determine the activation of MAPK signal pathway when osteosarcoma cell line MG-63, MNNG-HOS C1 exposed to the 50Hz,1mT ELF-EMF at different time points.Result:ELF-EMF inhibited the growth of osteosarcoma cells in a time-dependent manner. The survival rate of osteosarcoma cells was merely 20% when they were exposed to ELF-EMF for 3 hours. ELF-EMF induced the apoptosis of osteosarcoma cells and elevated the level of ROS. But the apoptosis rate of osteosarcoma cells in the ELF-EMF declined dramatically when they were treated with ROS inhibitor NAC. MAPKp38 in osteosarcoma cell lines was phosphorylated, and activated MAPKp38 pathway, but the phosphorylation level of MAPKp38 was inhibited following the NAC and ELF-EMF exposure. In addition, the apoptosis rate declined obviously after adding the p38 MAPK inhibitors SB203580.Conclusion:ELF-EMF induced the apoptosis of osteosarcoma via elevating ROS level and activating MAPKp38 signal pathway.