Nylund R, Tammio H, Kuster N, Leszczynski D. (2009). Proteomic Analysis of the Response of Human Endothelial Cell Line EA.hy926 to 1800 GSM Mobile Phone Radiation. J Proteomics Bioinform. 2:455-462.
The issue of the potential health effects of exposure to radiation from mobile phones remains controversial. Finding genes and proteins responding to mobile phone radiation may help find out whether such exposure can pose any health risk. In an earlier study, the author demonstrated that exposure of human brain capillary endothelial cell line EA.hy926 to 900 MHz GSM caused changes in protein expression. Endothelial cells were selected because in some animal experiments it was shown that radiation emitted by mobile phones might affect function of the blood-brain barrier.
The objective was to examine whether exposure to 1800 MHz GSM signal also affects protein expression in the same cell line.
Cells in one of the two chambers were exposed to 1800 MHz GSM signal (SAR=2.0 W/kg) for one hour at 37±0.3°C. Cells in the other chamber were sham-exposed for one hour at the same temperature. Proteins were extracted and separated using 2-dimensional electrophoresis (2DE).
Results and Interpretation
Ten replicates were generated from both radiation-exposed and sham-exposed samples. About 900 protein spots were detected in the 2DE gels using PDQuest 7.2 software. Eight protein spots were differentially expressed in the radiation exposed cells: expression of four proteins was down-regulated and expression of four proteins was up-regulated by the exposure. Three of these eight protein spots were identified using Maldi-ToF mass spectrometry (MS): spermidine synthase (SRM), 78 kDa glucose-regulated protein (GRP78) and proteasome subunit alpha type 1 (PSA1). Expression of GRP78 was further examined using western-blot technique, and this technique did not confirm the results obtained with 2DE. The western-blot technique has not detected any effect of the 1800 MHz GSM radiation on the expression of vimentin and Hsp27, the proteins that were affected by the 900 MHz GSM exposure in the earlier experiment. In general, the number of proteins significantly affected by the 1800 MHz GSM radiation in this experiment is smaller than the number observed in the earlier experiment with 900 MHz GSM radiation. The discrepancies between the results of the two experiments may be explained by different frequencies or by different distribution of radiation field within the cell culture (non-uniform SAR distribution in the 900 MHz set-up), or by both factors.
The results suggest that expression of some proteins in the EA.hy926 cells may be affected by exposure to 900 MHz and 1800 MHz GSM signals. The discrepancy between the results for GRP78 expression obtained by the two different methods indicates the importance of validation of 2DE results using other methods, such as western-blot.