Impact of 60‐GHz millimeter waves and corresponding heat effect on endoplasmic reticulum stress sensor gene expression

Abstract

Emerging high data rate wireless communication systems, currently under development, will operate at millimeter waves (MMW) and specifically in the 60 GHz band for broadband short-range communications. The aim of this study was to investigate potential effects of MMW radiation on the cellular endoplasmic reticulum (ER) stress. Human skin cell lines were exposed at 60.4 GHz, with incident power densities (IPD) ranging between 1 and 20 mW/cm(2) . The upper IPD limits correspond to the ICNIRP local exposure limit for the general public. The expression of ER-stress sensors, namely BIP and ORP150, was then examined by real-time RT-PCR. Our experimental data demonstrated that MMW radiations do not change BIP or ORP150 mRNA basal levels, whatever the cell line, the exposure duration or the IPD level. Co-exposure to the well-known ER-stress inducer thapsigargin (TG) and MMW were then assessed. Our results show that MMW exposure at 20 mW/cm(2) inhibits TG-induced BIP and ORP150 over expression. Experimental controls showed that this inhibition is linked to the thermal effect resulting from the MMW exposure.

Effects of 60-GHz millimeter waves on neurite outgrowth in PC12 cells using high-content screening

“…We reported that levels of several stressinducible genes were not significantly enhanced [29,32], suggesting that MMW around 60…”

Effects of Long-Term Exposure to 60 GHz Millimeter-Wavelength Radiation on the Genotoxicity and Heat Shock Protein (Hsp) Expression of Cells Derived from Human Eye

“…Nicolaz et al [22] described that exposure to 60.4 GHz radiation at a power density of 0.14 mW/cm 2 did not cause endoplasmic reticulum stress in human glial cells. Le Dréan’s group has also published studies on the effects of 60.4 GHz radiation [23,24,25]. Le Quément et al [23,24] showed no significant differences in gene expression following exposure to millimeter-wavelength radiation: although after 6 h exposure at 20 mW/cm 2 real-time PCR analysis showed that some gene expression levels were affected, and this effect was linked to the increased temperature caused by exposure.…”

“…Le Dréan’s group has also published studies on the effects of 60.4 GHz radiation [23,24,25]. Le Quément et al [23,24] showed no significant differences in gene expression following exposure to millimeter-wavelength radiation: although after 6 h exposure at 20 mW/cm 2 real-time PCR analysis showed that some gene expression levels were affected, and this effect was linked to the increased temperature caused by exposure. Haas et al [25] also indicated that a slight increase in protein expression observed following exposure to 60.4 GHz for 24 h was related to heating, and that there were no differences in the protein expression of neuronal marker β-tubulin or in the internal expression of control β-tubulin, consistent with our data.…”

Millimeter‐Wave Heating in In Vitro Studies: Effect of Convection in Continuous and Pulse‐Modulated Regimes

“…Before exposure, the medium was replaced by DMEM without sodium bicarbonate (Ref. 12800‐017; Thermo Fisher Scientific, Waltham, MA) containing 4.6 mM of Hepes (Thermo Fisher Scientific) to maintain constant pH in the non‐gassed incubator of the exposure system [Le Quément et al, ]. SUT 4 . Agar gel (98.5% of distilled water and 1.5% of agar) was used as a reference water‐equivalent model without convection.…”