McNamee JP, Chauhan V. 2009. Radiofrequency radiation and gene/protein expression: a review. Radiat Res. 172(3):265-287.
Current epidemiological evidence of health risks from exposure to low-level radiofrequency (RF) radiation is inconclusive. Therefore, it is important to consider laboratory evidence of biological plausibility and potential mechanisms of such effects. The authors have reviewed scientific literature on changes in protein and gene expression induced by low-level RF radiation.
Heat-Shock Proteins (HSPs)
The HSPs, or “stress proteins” are expressed in response to environmental stresses. The majority of studies suggest that non-thermal RF-radiation exposures do not result in a cellular stress response characterized by altered HSP gene or protein expression. However, because such an effect was observed in a small number of studies with seemingly well-controlled exposure conditions, further research is required to determine whether these observations reflect “true” biologic response or they are related to some unknown uncontrolled variable.
Proto-oncogenes are genes whose protein products can induce cellular transformation. These genes are normally expressed at low levels but their expression is stimulated by stressful external factors. The authors have concluded that current scientific evidence does not support the hypothesis that non-thermal RF radiation alters proto-oncogene activation.
Signal Transduction Pathways
Cells regulate transcriptional activity in response to stressors through the mitogen-activated protein kinase (MAPK) pathways including the extracellular-signal regulated kinase (ERK), p38 and the 1/2 c-Jun N-terminal kinase (JNK) cascades. In particular, these pathways regulate cell proliferation, differentiation and metabolism. Similar to HSPs and the protooncogenes, studies on proteins and genes associated with signal transduction pathways involved in stress response have produced mixed results. There is no conclusive evidence that RF radiation can affect signal transduction pathways.
Microarray Studies Assessing the Effects of RF Radiation on Gene Expression
This technology is very useful for screening large numbers of genes for potential interaction with a test agent. However, there are a number of deficiencies in microarray studies. At this time, there is no convincing evidence of differential gene expression after exposure to non-thermal RF-radiation.Additional high-quality studies conducted according to best practices for microarray analysis are required.
The weight of evidence does not support the hypothesis of specific, non-thermal effect of RF radiation at the gene or protein level. However, because several well-conducted studies produced evidence of possible RF-radiation-induced gene/protein interaction, further research is warranted. To resolve existing discrepancies, future studies should have a sound experimental design and implement rigorous statistical analysis.