Nylund R, Kuster N, Leszczynski D. Analysis of proteome response to the mobile phone radiation in two types of human primary endothelial cells. Proteome Sci. Oct 18, 2010;8(1):52. Ahead of print.
Use of mobile phones has widely increased over the past decade. However, in spite of extensive research, the potential health effects of mobile phone radiation remain unknown. Proteomics are a promising tool to study the biological effects of mobile phone radiation as past studies have shown that proteins respond to exposure.
The objective of this study was to determine the effects of exposure of 1800 MHz GSM mobile phone radiation on the proteome of human endothelial cell line EA.hy926 cells.
Primary human umbilical vein endothelial cells (HUVEC) and primary human brain microvascular endothelial cells (HBMEC) were separated into sham (unexposed control) and exposure groups (13 different groups for HUVEC, 11 different groups for HBMEC) in CellBIND Petri dishes. Dishes were placed in one of two identical exposure chambers mounted inside the same cell culture incubator. A computer controlled whether a chamber was exposed to an 1800 MHz GSM signal with an average SAR of 2.0 W/kg at 37 ± 0.3°C for 1 hour, or no signal (sham exposure) for the same duration of time at the same temperature. Cells were harvested immediately after the exposure and protein expression patterns were examined using two dimensional difference gel electrophoresis-based proteomics (2DE-DIGE).
Proteome analysis indicated differences in 2D protein expression patterns between HUVEC and HBMEC. After correcting for false discovery rate (FDR), 368 spots were found to differ between both cell types (p≤0.0001) and 145 spots were found to be differentially expressed by more than 2-fold up or down. Since the different physiological properties of the two cell types may lead to the induction of different protein expression profiles, differences in protein expression were analyzed for 1746 spots included in an Extended Data Analysis (EDA) module. In the HUVEC proteome there were 35 statistically significantly affected protein spots (p≤0.05) and in the HBMEC proteome there were 2 statistically significantly affected protein spots (p≤0.05) observed between sham and exposed samples. However, when FDR correction was performed, all statistically significantly affected spots were recognized as false positives.
Interpretation and Limitations
Exposure of HUVEC and HBMEC to 1800 MHz GSM mobile phone radiation did not cause any statistically significant changes in their proteomes. This result differs from earlier studies where human endothelial cell lines were exposed to 900 MHz GSM mobile phone signals and statistically significant changes in proteome were detected, but agrees with more recent studies using 1800 MHz GSM radiation. Differences with past studies could be a result of different exposure frequencies (900 MHz vs. 1800 MHz), differences in SAR distribution in cell culture dishes used in exposure set-ups, differences in cell types, and differences in the 2DE proteomics methodology. A limitation of this study is that the results are difficult to extrapolate to humans.
This study suggests that exposure of primary human endothelial cells to mobile phone radiation of 1800 MHz GSM for 1 hour does not affect protein expression.