Roux D, Girard S, Paladian F, Bonnet P, Lalléchère S, Gendraud M, Davies E, Vian A. Human keratinocytes in culture exhibit no response when exposed to short duration, low amplitude, high frequency (900 MHz) electromagnetic fields in a reverberation chamber. Bioelectromagnetics. Ahead of print. Dec 22, 2010.
Environmental electromagnetic radiation has increased dramatically in recent years, mainly because of the massive development of wireless communication devices. Possible effects of such radiation on living organisms have long been questioned.
The objective of this study was to determine if gene expression is modified in normal human epidermal keratinocytes exposed to short duration, high frequency, and low amplitude electromagnetic fields (EMF).
Non-transformed, non-tumor human epidermal keratinocytes were incubated in culture dishes until they reached 70% confluence. Cells were then randomly selected from first subcultures for exposed or sham samples. Eight boxes of cells were housed in a reverberation chamber and either subjected to a sham exposure or one of two non-thermal exposure conditions: a 10-min exposure with a field amplitude of 8 V/m, or a 30 min exposure with a field amplitude of 41 V/m. Corresponding specific absorption rates ranged from 2.6 to 73 mW/kg (continuous wave, 900 MHz carrier frequency). RNA was collected from the cells and a large-scale microarray screening was conducted for over 47000 human genes.
Exposure of keratinocytes to either level of EMF had very little effect. Only 20 genes displayed significant modulation. These genes were associated with various cellular functions such as receptor activity, signaling pathways, cell growth and proliferation, and regulation of metabolism. However, the expression ratios were very small (close to 1.5-fold change), and none of them were shared by the two tested conditions. Those assayed using polymerase chain reaction also did not display significant expression modulation (overall mean of the exposed samples was 1.20 + 0.18).
Interpretation and Limitations
The results of this study agree with previous results demonstrated by the authors of a link between low amplitude, short duration high-frequency EMF exposure and stress-related mRNA accumulation in tomato plants. The present study indicates that cultured skin cells in vitro are far less responsive to EMF than cells of intact plants and differences between the responses may be related to the monolayer cell culture. Limitations of this study are it was conducted in vitro and it is unknown if human keratinocytes would be more sensitive to high-frequency EMF in vivo.
This study suggests that cultured keratinocytes are not significantly affected by EMF exposure.