Exploring The Biological Effects Of1800MHz GSM Mobile Phone Radio Frequency Electromagnetic Fields Through Identifying Its Responsive Cell Types

Whether exposure to the mobile phone radiation (MPR) can induce genotoxic effect is a key issue in its health risk assessment. Different research groups have used different cell types, exposure systems, exposure parameters and detection technique in the genotoxic studies that make it remain contradictory and inconclusive. A number of studies have shown that different cells might respond differently under the same RF-EMF exposure model and testing method. So more sensitive method and systematic research strategy are warranted to evaluate its genotoxicity, and study based on sensitive cell types would be promising to elucidate the real biological effects induced by MPR and its underlying mechanism of action.To systematically investigate the effects of RF-EMF on DNA damage, we examined and compared yH2AX foci formation in six cell types after1800MHz GSM (global system for mobile communications) RF-EMF exposure, determined whether RF-EMF induce DNA damage is cell-type dependent, and investigated the biological consequences if RF-EMF does increase yH2AX foci formation in MPR-sensitive cells.The data showed that intermittent exposure of cells to1800MHz MPR at a specific absorption rate (SAR) of3W/kg for1hour did not induce statistically significant changes in any of the six examined cell types, i.e., Chinese hamster lung cells (CHL), astrocytes, human amnion epithelial cells (FL), human umbilical vein endothelial cells (HUVEC), human lens epithelial cells (HLEC) and human skin fibroblasts cells (HSF). Following the24-hr exposure, the average number of yH2AX foci per cell increased significantly in CHL and HSF but not in the remaining four cell types.Further, the cell DNA fragments were determined by comet assay, cell cycle progression by flow cytometry with PI staining, proliferation by cell counting, viability with Cell Counting Kit-8colorimetric assays,53BP1and RAD51foci formation with immunofluencese and the intracellular radical oxygen species (ROS) level by flow cytometry with DCFH-DA staining using the MPR-sensitive cell-HSF. RF-EMF-elevated yH2AX foci formation in HSF cells did not result in detectable DNA fragmentation, sustainable cell cycle arrest, cell proliferation or viability change and53BP1and Rad51foci formation. RF-EMF exposure slightly but not significantly increased the cellular ROS level.Conclusions:1) MPR induces yH2AX foci formation in a time-related and cell type-dependent manner;2) CHL and HSF cells were approved as the RF-EMF relatively-sensitive cells;3) A slight increase of yH2AX foci formation does not affect cell behaviors.Innovations:strategies and methods,1) According to our knowledge, this is the first study using more sensitive method to systematically investigate and compare the effect of MPR on DNA damage in different cell types;2) This is the first study exploring the biological effects of1800MHz GSM mobile phone RF-EMF through identified relatively-sensitive cells. Results:1) CHL and HSF were identified as RF-EMF relatively-sensitive cells;2) RF-EMF-elevated yH2AX foci formation in HSF cells did not result in other biological effects.