Sakuri T, Kiyokawa T, Narita E, Suzuki Y, Taki M, Miyakoshi J. Analysis of Gene Expression in a Human-derived Glial Cell Line Exposed to 2.45 GHz Continuous Radiofrequency Electromagnetic Fields. J. Radiation Research, Advanced Publication, 2011.
Public concern about health effects due to increased cell phone use is increasing. Many groups have investigated whether this type of radiofrequency (RF) exposure changes the expression levels of genes within a cell. Any significant change could produce harmful changes within a cell and initiate adverse health effects. Today with a technique call ‘microarray analysis’ the expression levels of thousands of genes can be measured at the same time and this group investigates whether exposure to RF fields leads to any changes in gene expression levels.
The objective of this study was to determine if exposure to RF field for different periods of time causes changes in the expression levels of genes within a foetus-derived brain cell.
The cells used in this study were foetal brain cells. Several different RF exposures were analyzed for changes in gene expression patterns and compared to cells that were sham exposed for the same amount of time. Cell were exposed to RF fields at a 1 or 5 or 10 W/kg specific absorption rate for 1h, 4h and 24 hours. Cells were harvested and analyzed using microarray analysis. The expression levels of up to 10,000 different genes were analyzed and compared.
The researchers found 28 genes that were consistently expressed abnormally in the microarray; either the expression levels were too high or too low compared to sham exposed cells. To validate that the expression levels of these genes were not false positives, the expression levels of the genes were then reassessed individually using a more accurate and sensitive technique. Only 23/28 genes could be assessed by this method, but all those genes were found to be in the normal expression range after RF exposures. The researchers concluded that the 23 reassessed genes were within normal expression levels.
Interpretation and Limitations
The authors could not find any significant alterations in the gene expression patterns for any of the exposure times to RF fields. They believed the reasons for the false positives found in the microarray was due to the low expression levels of these genes that were beyond the accurate detection limits of the microarray analysis.
This study found no evidence that RF exposure of human foetal brains would cause any significant changes in gene expression levels under their experimental conditions.