Bioelectromagnetics 35:444^451 (2014)

Impact of 60-GHz Millimeter Waves and Corresponding Heat Effect on Endoplasmic Reticulum Stress Sensor Gene Expression Catherine Le Que¤ment,1 Christophe Nicolas Nicolaz,1,2 Denis Habauzit,1 Maxim Zhadobov,2 Ronan Sauleau,2 and Yves Le Dre¤an1* 1

Transcription, Environment and Cancer Group, Institute of Research in Environmental and Occupational HealthçIRSET, INSERM, University of Rennes 1, Rennes, France 2 Institute of Electronics and Telecommunications of RennesçIETR, University of Rennes 1, UMR CNRS, Rennes, France 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/cm2. 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/cm2 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. Bioelectromagnetics 35:444–451, 2014. © 2014 Wiley Periodicals, Inc. Key words: millimeter waves; 60-GHz band; biological effects; BIP; ORP-150; keratinocytes

INTRODUCTION Millimeter waves (MMW) are electromagnetic radiations with frequencies ranging from 30 to 300 GHz. They are increasingly employed in multiple applications [Pellegrini et al., 2013] including, body-centric wireless communications for high data rate transmission, remote security and localization techniques, and in several military applications (e.g., radars, non-lethal weapons). In this context, 60 GHz wireless systems represent a new anthropogenic factor and their potential biological effects, as a function of the power density, have to be carefully quantified. The strongest argument in favor of a possible interaction between MMW and living organisms is that these radiations have been utilized as a therapeutic modality in some Eastern-European countries [Rojavin and Ziskin, 1998]. Three specific frequencies have been employed (42.2, 53.6, and 61.2 GHz). For these medical applications, the MMW source is usually placed close to the skin (near-field exposure condition), inducing power densities typically ranging from 10 to 20 mW/cm2. Under these conditions, the exposures produce a low, but significant temperature increase [Alekseev and Ziskin, 2009], and therefore, the  2014 Wiley Periodicals, Inc.

biological effects cannot be classified as purely nonthermal. It is unclear whether the effects observed in therapy could be transferable under the conditions of use in other applications (e.g., telecommunication). The International Commission on Non-Ionizing Radiation Protection (ICNIRP) recommends limiting the 60 GHz incident power density (IPD) to 1 mW/cm2 under Grant sponsors: Bio-CEM Project, French National Research Agency (Agence Nationale de la Recherche, ANR); grant number: 09-RPDOC-003-01; BioREF Project, French National Research Agency; grant number: 10-CESA-017-01. Catherine Le Quément and Christophe Nicolas Nicolaz contributed equally to this study. *Correspondence to: Yves Le Dréan, Equipe “Transcription, Environnement et Cancer” IRSET, Université de Rennes 1, Campus de Beaulieu, Bât. 13, 263 ave. du G. Leclerc, 35042 Rennes Cedex, France. E-mail: [email protected] Received for review 6 December 2013; Accepted 17 May 2014 DOI: 10.1002/bem.21864 Published online 6 August 2014 in Wiley Online Library (wileyonlinelibrary.com).

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far-field exposure conditions (averaged over 20 cm2) for the general public [ICNIRP, 1998]. However, under near-field exposure conditions corresponding to some emerging body-centric application, the exposure level is limited to 20 mW/cm2 (averaged over 1 cm2). Another major challenge is the identification of cellular and molecular targets of these radiations [Zhadobov et al., 2011]. Despite the existence of a few theories regarding non-thermal MMW interactions, their exact mechanisms remain unknown, and therapeutic applications of low-power MMW are based mainly on empirical data. However, few reported data have shown that MMW radiations may interfere with some cellular processes [Le Drean et al., 2013]. MMWs around 60 GHz, with power levels (roughly 0.4 mW/cm2) close to those typically expected from wireless communication systems, have been shown to induce structural modifications in artificial biomembranes [Zhadobov et al., 2006]. It was also demonstrated that 53 GHz radiations (0.1 mW/cm2) could induce physical changes and modify permeability of phospholipid vesicles [Ramundo-Orlando et al., 2009]. Reversible externalization of phosphatidylserine was also observed for different exposed cell lines (42.25 GHz, 34.5 mW/cm2) without detectable membrane damage [Szabo et al., 2006]. Moreover, in vitro experiments using an epithelial cell line expressing a farnesylated green fluorescent protein showed that a 2 min MMW exposure (50 GHz, 1–3 mW/cm2) induced a membrane depolarization [Seigel and Pikov, 2010]. Besides, results of experiments on kidney cells, using the patch voltage-clamp method, suggest that MMW (42.25 GHz, 100 mW/cm2) can alter the activation of Ca2þ-activated Kþ channels by decreasing its affinity for internal Ca2þ [Geletyuk et al., 1995]. Furthermore, Ca2þ dynamics in mouse embryonic stem cell-derived neuronal cells seem to be modulated by high-power 94-GHz radiations at 1.86 W/cm2 [Titushkin et al., 2009]. Taken together, all these data suggest that cellular organelles containing membranes and calcium, for example endoplasmic reticulum (ER), could be potential targets for MMW. The endoplasmic reticulum, which is the site of synthesis and folding of secreted proteins, is known to be very sensitive to environmental insults [Romanoski et al., 2010]. At the present time, very few articles have been published about the MMW impacts on ER. Analyses by transmission electron microscopy have revealed ultrastructural modifications of the rough endoplasmic reticulum in MMW-irradiated hematopoietic cells (53–78 GHz, 1 mW/cm2) [Beneduci et al., 2007]. Besides, 30/40-GHz MMW (4 mW/cm2) exposures were reported to induce enrichment and development of ER in exposed mesenchymal stem

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cells [Wu et al., 2009]. However, our group has recently demonstrated that low-power MMW (0.14 mW/cm2) within 59–61.2 GHz frequency range does not affect the basal ER homeostasis in the human cell line [Nicolas Nicolaz et al., 2009a,b]. The aim of this work is to further investigate the effect of a 60 GHz exposure at various power densities, on basal or stress-induced expression of ER chaperons BIP and ORP150, in order to identify possible power thresholds of induced effects and compare them with the thermal thresholds. MATERIALS AND METHODS Millimeter-Wave Exposure Set-Up and Temperature Measurements The main units of the exposure set-up and our dosimetry approach were described and characterized in detail in previous reports [Zhadobov et al., 2009, 2012]. The six-well tissue culture plate that contained the cells was placed in the MEMMERT UE400 incubator (Fisher Scientific, Illkirch, France) at 37 8C and irradiated from the bottom by a standard pyramidal horn antenna (The antenna was built few years ago at the Institute of Electronics and Telecommunications of Rennes. Dimension and characteristics were previously described in the cited publications [Zhadobov et al., 2009, 2012]). Under far-field conditions, the sixwell plate was fully exposed with a maximal averaged over the cell layer IPD of 1.8 mW/cm2. Under nearfield conditions, only one well per plate was exposed at a time, with a maximal averaged IPD of 20 mW/ cm2. This exposure limit was chosen according to the ICNIRP recommendation [ICNIRP, 1998]. Temperature elevations within the culture medium were locally monitored within central wells using a Reflex multichannel optical fiber thermometer (Neoptix, Québec City, Canada) [Zhadobov et al., 2012]. The temperature dynamics were measured at the tip of the optical fiber with a diameter of 0.4 mm and a 1 Hz sampling rate. Cell Culture and Exposure Protocol Since more than 90% of MMW power is absorbed in the superficial layers of the skin [Zhadobov et al., 2011], we carried out this study by using keratinocyte and melanocyte cell lines. The human malignant melanoma cell line A375 (American Type Cultures Collection (ATCC), Biovalley, Marne-laVallée, France), and the human keratinocyte cell line, HaCaT (kindly provided by Dr. M-D. Galibert-Anne, University of Rennes 1, Rennes, France), were cultured in Dulbecco’s modified Eagle medium (Gibco/ Bioelectromagnetics

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Life Technologies, Saint Aubin, France) supplemented with 10% fetal calf serum (FCS), 1% antibiotics and 1% L-glutamine, in a humidified incubator at 37 8C and an atmosphere of 5% CO2. Cells (16000 cells/ cm2) were transferred to six-well plates one day before exposure to MMW. The cells were exposed to MMW for 20 min, 1 h, 6 h, 16 h, or 24 h with an IPD ranging between 1 and 20 mW/cm2. Sham exposures were performed under identical experimental conditions, but with the generator switched off. Three to five independent biological replicates per condition were used. As positive control for stress induction, cells cultured under the same conditions were treated for 16 h with thapsigargin (Sigma, Saint-Quentin Fallavier, France), a drug which triggers ER stress by selectively inhibiting the ER Ca2þ-ATPase pump. Plasmids and Transient Transfection The reporter plasmid pBiP304/þ7-luc, containing the firefly luciferase reporter gene placed under the control of the human BIP gene promoter [Yoshida et al., 1998], was kindly provided by Dr. K. Mori (Department of Biophysics, Graduate School of Science, Kyoto, Japan). For the normalization of the assays, a TK-Renilla luciferase vector (pTK-luc; Promega, Charbonnieres, France) was used; pBIP304/þ7-luc and pTK-luc vectors were transiently transfected in either A375 cells or HaCaT cells using JetPei DNA transfection reagent (Polyplus Transfection, Illkirch, France), according to the manufacturer’s procedures. Twenty-four hours after transfection, cells were treated or not with the thapsigargin, an ER-stress inducer (TG 0, 2, 4, or 6 nM), and exposed or not to MMW for 16 h. At the end of the exposure, cells were harvested and the luciferase activities were determined with dual luciferase assay system (Promega). Real Time RT-PCR Analysis RNAs from exposed cells were extracted with TRIzol reagent (Invitrogen, Saint Aubin, France), and then 2 mg of RNAs were retro transcribed using M-MLV Reverse Transcriptase (Invitrogen). Then, the resulting cDNA were used to perform real-time quantitative reverse transcription polymerase chain reaction (RT-PCR) using 200 nM of each sense and antisense primers (sequences indicated in Table 1), and iQ SYBR Green Supermix (Bio-Rad, Marnes-la-Coquette, France). Amplification of each studied gene (BIP (immunoglobulin heavy-chain binding protein, also known as HSPA5: Heat Shock 70 kDa Protein 5 (Glucose-Regulated Protein, 78 kDa)), and ORP150 (150 kDa oxygen-regulated protein, also known as HYOU1: Hypoxia Up-Regulated 1)) was normalized Bioelectromagnetics

using the amplification of three housekeeping genes (glyceraldehyde-3-phosphate dehydrogenase (GAPDH), Hypoxanthine guanine phophoribosyltransferase 1 (HPRT1) and TATA box binding protein (TBP), sequences are indicated in Table 1). Polymerase chain reaction (PCR) products were measured continuously with MyIQ Real-Time PCR detection system (Bio-Rad). All data were implemented in Gene Expression software (Bio-Rad), and relative changes in gene expression were analyzed using the delta Ct method [Winer et al., 1999]. RESULTS Effect of Exposure Durations on Basal ER-chaperons Expression We measured the mRNA levels of two ERresident chaperons, BIP and ORP150, known to be over expressed during ER stress [Nicolas Nicolaz et al., 2009a]. In HaCaT, TG treatment (1 mM, 16 h) increased the BIP and ORP150 mRNA levels by 12and 8-fold, respectively (black histograms, Fig. 1A,B). These data validate BIP and ORP150 utilization as sensitive biosensors to detect ER stress. Cell cultures were irradiated for various durations (20 min, 1 h, 6 h, or 24 h) at 60.4 GHz, with an average IPD of 1.8 mW/ cm2. Quantitative RT-PCR analysis did not show any change in BIP (Fig. 1A) and ORP150 (Fig. 1B) basal expressions, no matter the duration of the exposure. Same results were observed in the malignant A375 melanoma cell line (data not shown). Effect of IPD Increase on Basal ER-chaperons Expression In order to identify IPD thresholds corresponding to the potential induction of an ER stress, we increased the IPD up to 20 mW/cm2 under near-field exposure conditions, as reported in [Zhadobov et al., 2012]. The cells were exposed or sham-exposed at 60.4 GHz with average IPD ranging from 1 to 20 mW/cm2 for 24 h. Then, by real-time RT-PCR, we measured the basal expression levels of BIP and ORP150. As shown in Figure 2A, we did not observe any significant modification of BIP mRNA levels, regardless of the IPD used. Concerning the ORP150 transcript, a slight decrease of the basal expression was measured at 15 and 20 mW/cm2, but this decrease is not statistically significant (Fig. 2B). A temperature control experiment was carried out because exposure to high power MMW results in significant heating. Temperature was recorded at the centre of the well of the tissue culture plate at 1 mm above the bottom of the well. The temperature rise is proportional to the IPD level, and the medium

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TABLE 1. PCR Primers Gene name and symbol Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) TATA-box binding protein (TBP) Hypoxanthine-guanine phosphoribosyltransferase (HPRT1) Immunoglobulin heavy-chain binding protein (BIP) Oxygen-regulated protein 150 kDa (ORP150) Heat shock protein 70 kDa (HSP70A1A) Heat shock protein 27 kDa (HSP27)

Forward primer

Reverse primer

TGCACCACCAACTGCTTAGC

GGCATGGACTGTGGTCATGAG

TGCACAGGAGCCAAGAGTGAA

CACATCACAGCTCCCCACCA

TGACACTGGCAAAACAATGCA

GGTCCTTTTCACCAGCAAGCT

CTCGAATTCCAAAGATTCAGCAACT

CTCCCACAGTTTCAATACCAAGTG

TGCAGTGATCACCGTGCCAG

TCTTTCCGGCGGAAGACACC

AGGCCGACAAGAAGAAGGTGCT

TGGTACAGTCCGCTGATGATGG

CAGGACGAGCATGGCTACATCT

GGGATGGTGATCTCGTTGGAC

temperature reached was 42.98  0.1 8C at an IPD of 20 mW/cm2. We therefore considered the expression of two members of the cytosolic Heat shock protein (HSP) family: HSP27 and HSP70. Those messengers are usually synthesized in response to heat shock or other proteotoxic stress. The RNAs were collected and the specific transcript levels were measured by realtime RT-PCR. Between 0 and 10 mW/cm2, neither

Fig. 1. Prolonged MMW exposures do not modify basal expression of the ER-stress-related genes BIP (A) and ORP150 (B). Results were expressed in fold of induction, normalized to the sham samples for the duration of each exposure. Data are expressed as mean  SD of three independent exposure experiments.

HSP27 nor HSP70 were induced by MMW after 24 h of exposure. However, a significant 10 and 12-fold increase of HSP27 and HSP70 were observed after 24 h MMW-exposure with an IPD of 20 mW/cm2, respectively (Fig. 2C). These HSP mRNA induction levels are identical to those obtained after a heat shock control (data not shown). Effect of MMW Exposure on ER-stress Induced BIP and ORP150 Expression We then aimed to assess the TG and MMW coexposure effect for several IPD values. This analysis was first performed on transient transfection of luciferase reporter construct driven by the human BIP promoter. Cells were treated with increased concentrations of TG (0, 2, 4, 6 nM; Fig. 3A), which induced a concentration-dependent increase of the luciferase activity before reaching a plateau for doses ranging from 10 nM to 1 mM (data not shown). This ER stress response was not modified by the MMW exposure at 1.8 mW/cm2 (Fig. 3A). In addition, we assessed the level of endogenous BIP mRNA by RT-PCR after a treatment with TG at 6 nM during 16 h, in combination or not with the MMW exposure. TG treatment induced an increase of BIP mRNA levels, but we did not observed any impact of the MMW exposure on the relative amount of BIP transcript after TG treatment (Fig. 3B). These experiments were also performed on A375 cell line and similar results were obtained (data not shown). Consequently, we performed a co-treatment with thapsigargin and MMW exposure at 20 mW/cm2. Contrary to what we have observed previously for low-power exposures, here we obtained a complete Bioelectromagnetics

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controls were performed to verify that the TG activity is not heat sensitive (data not shown). In order to verify whether thermal effects are responsible for the ER stress response inhibition observed after MMW exposure, we cultured the HaCaT cells in the same conditions as during the sham experiment, but at 43 8C. In these conditions, the gene expressions of HSP27 and HSP70 were multiplied by 11.5 and 12.8, respectively (data not shown). These inductions are similar to those obtained with MMW exposure at 20 mW/cm2. Moreover, as previously found with the MMW exposure at 20 mW/cm2, a temperature of 43 8C prevented the TG-induction of BIP (Fig. 3E) and of ORP150 (Fig. 3F), whereas it had no impact on the basal expression of these genes. These data clearly indicate that MMW-inhibition of ER stress response can be mimicked by a temperature elevation in the culture medium. DISCUSSION

Fig. 2. High power MMW exposures do not modify basal expression of the ER-stress-related genes, but increase the HSP gene expression. BIP (A), ORP150 (B) or HSP27 andHSP70chaperones (C) transcript levels were measured by real-time RT-PCR. Results were expressed in fold of induction, normalized to the sham samples. Data are expressed as mean  SD of three independent exposure experiments.

inhibition of the TG induction when cells were exposed to MMW at high IPD. Indeed, during a 16 h exposure at 20 mW/cm2, treatment with TG no longer results in an induction of BIP (Fig. 3C) and ORP150 (Fig. 3D). To ensure that this decline in induction is not due to a problem of TG stability under exposure, we used a higher dose of TG (1 mM) and additional Bioelectromagnetics

Several indications in scientific literature suggest that membrane-rich cellular organelles, such as ER, could be potential targets of MMW. We previously proved that ER homeostasis does not undergo any modification at molecular level after exposure to lowpower (0.14 mW/cm2) MMW radiations around 60 GHz [Nicolas Nicolaz et al., 2009a,b]. Therefore, it was interesting to further investigate the effects of high-power MMW, especially for IPD close to the ICNIRP limits set for the general public (1 or 20 mW/ cm2, depending on exposure scenarios). This study shows that MMW radiations do not change the basal expression of the ER chaperones, BIP and ORP150, whatever the cell line, the duration of exposure or the IPD used. However, the ER chaperones over expression induced by TG treatment was completely ablated in cells exposed to MMW at 20 mW/cm2, demonstrating that for high IPD, MMW radiations could interfere with ER stress response. It is important to notice that this repression occurs with exposure conditions that induce an important temperature increase. Measurement of the temperature dynamics in our in vitro exposure system showed that at 20 mW/cm2, the temperature in the culture medium rises up to 43 8C. However, this temperature is not lethal for our cellular model, probably because of the peculiarity of the cellular model used. Indeed, due to the barrier function of the skin, the keratinocytes are resistant to many environmental insults. We verified that under these conditions, cells are still physiologically able to respond to stress. Heat effect associated with high IPD exposure increase HSP27 and HSP70 gene expressions, which indicates that the inhibition of ER stress

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Fig. 3. Co-treatment of thapsigargin and MMW exposure. (A and B) HaCaT cells were sham-exposed or exposed at 60.4 GHz with an average IPD of 1.8 mW/cm2, during 16 h. Cells were transfected with pBiP 304/þ7-luciferase reporter vector, and treated with various concentrations of thapsigargin (TG: 0, 2, 4, 6 nM) during the exposure duration (A).The firefly luciferase activity was normalized to renilla luciferase activity and the promoter activity was expressed as the fold of induction over the control without TG. Using real-time PCR, mRNA levels of endogenous BIP were measured (B).Cells exposed or sham-exposed to MMW were stimulated with 6 nM thapsigargin, ornot (DMSO). (Cand D) HaCaT cellswere sham-exposed orexposedat 60.4 GHz withanaverage IPD of 20 mW/cm2, during16 h.Using RT-PCR, mRNAlevels of BIP (C) and ORP150 (D) were measuredin cellsco-treated, ornot (DMSO), with1 mM thapsigargin. (Eand F) HaCaT cellswere stimulated with thapsigargin (TG 1 mM) at 37 8C or 43 8C, during 16 h. Using RT-PCR, mRNA levels of BIP (E) and ORP150 (F) were measured. Expression data were normalized by three reference genes, and the resultswere expressed in fold of induction, normalized to the DMSO control conditionat 37 8C.Dataare expressedasmean  SDofthreetofiveindependentexposure experiments. NS: not statistically different,  P < 0.05;  P < 0.01;  P < 0.005, when using a Welch two sample Student’s t-test.

response is specific and not related to a global transcriptional decrease or to the cell death. Furthermore, we showed that the ER stress response to TG could also be reduced by an incubation of cells at 43 8C. This observation suggests that the repressor effect of MMW radiations on ER stress response can be attributed to the associated thermal effect. In fact, interferences between ER stress and heat shock responses have already been described in the

literature. Until now, it was shown that heat shock induces ER stress rather than represses it [Xu et al., 2011; Liu et al., 2012; Zhu et al., 2012]. It is noteworthy that this induction occurs for milder heat shock. Moreover, it seems that sensitivity to heatinduced ER stress depends on cell type and may involve an atypical signaling pathway [Heldens et al., 2011; Liu et al., 2012]. However, when cells were subjected to a severe heat shock (43 8C for 3–6 h), Bioelectromagnetics

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BIP mRNA expression was found to be repressed by approximately 50% [Xu et al., 2011]. The exact molecular mechanism is still unknown, even if it was postulated that heat shock in a second step could block and render the transcriptional activation of ER-stress response unproductive [Heldens et al., 2011]. In conclusion, we found that MMW alone do not trigger ER stress on keratinocytes, which are their main cellular targets. This study also shows that MMW exposure with IPD levels close to the exposure limits averaged over 1 cm2 could lead to some inhibitory effects in cells that are already ER stressed. However, at this high IPD level, MMW generate a heat effect and we demonstrated that the MMW exposure threshold is correlated to this thermal effect. As ER stress response is a biological process known to be involved in pathogenesis of many human diseases [Wang and Kaufman, 2012], this information is relevant for the safety evaluation of emerging MMW wireless communication systems. Therefore, it will be important to confirm this MMW interference on in vivo models, before having to rethink the current near-field standards. ACKNOWLEDGMENT The authors thank Catherine Martin for her technical assistance. REFERENCES Alekseev SI, Ziskin MC. 2009. Influence of blood flow and millimeter wave exposure on skin temperature in different thermal models. Bioelectromagnetics 30:52–58. Beneduci A, Chidichimo G, Tripepi S, Perrotta E, Cufone F. 2007. Antiproliferative effect of millimeter radiation on human erythromyeloid leukemia cell line K562 in culture: Ultrastructural- and metabolic-induced changes. Bioelectrochemistry 70:214–220. Geletyuk VI, Kazachenko VN, Chemeris NK, Fesenko EE. 1995. Dual effects of microwaves on single Ca(2þ)-activated Kþ channels in cultured kidney cells Vero. FEBS Lett 359: 85–88. Heldens L, Hensen SMM, Onnekink C, van Genesen ST, Dirks RP, Lubsen NH. 2011. An atypical unfolded protein response in heat shocked cells. PLoS ONE 6:e23512. ICNIRP. 1998. Guidelines for limiting exposure to time varying electric, magnetic, and electromagnetic fields (up to 300 GHz). Health Phys 74:494–522. Liu Y, Sakamoto H, Adachi M, Zhao S, Ukai W, Hashimoto E, Hareyama M, Ishida T, Imai K, Shinomura Y. 2012. Heat stress activates ER stress signals which suppress the heat shock response, an effect occurring preferentially in the cortex in rats. Mol Biol Rep 39:3987–3993. Le Drean Y, Soubere Mahamoud Y, Le Page Y, Habauzit D, Le Quement C, Zhadobov M, Sauleau R. 2013. State of knowledge on biological effects at 40–60 GHz. Comptes Bioelectromagnetics

Rendus de l’Académie des Sciences—Physique 14: 402–411. Nicolas Nicolaz C, Zhadobov M, Desmots F, Sauleau R, Thouroude D, Michel D, Le Dréan Y. 2009a. Absence of direct effect of low-power millimeter-wave radiation at 60.4 GHz on endoplasmic reticulum stress. Cell Biol Toxicol 25:471–478. Nicolas Nicolaz C, Zhadobov M, Desmots F, Ansart A, Sauleau R, Thouroude D, Michel D, Le Dréan Y. 2009b. Study of narrow band millimeter-wave potential interactions with endoplasmic reticulum stress sensor genes. Bioelectromagnetics 30:365–373. Pellegrini A, Brizzi A, Zhang L, Ali K, Hao Y, Wu X, Constantinou CC, Nechayev Y, Hall PS, Chahat N, Zhadobov M, Sauleau R. 2013. Antennas and propagation for body-centric wireless communications at millimeterwave frequencies: A review. IEEE Antennas Propag Mag 55:262–287. Ramundo-Orlando A, Longo G, Cappelli M, Girasole M, Tarricone L, Beneduci A, Massa R. 2009. The response of giant phospholipid vesicles to millimeter waves radiation. Biochim Biophys Acta 1788:1497–1507. Rojavin MA, Ziskin MC. 1998. Medical application of millimetre waves. QJM 91:57–66. Romanoski CE, Lee S, Kim MJ, Ingram-Drake L, Plaisier CL, Yordanova R, Tilford C, Guan B, He A, Gargalovic PS, Kirchgessner TG, Berliner JA, Lusis AJ. 2010. Systems genetics analysis of gene-by-environment interactions in human cells. Am J Hum Genet 86:399–410. Seigel PH, Pikov V. 2010. Impact of low intensity millimetre waves on cell functions. Electron Lett S70–S72. Szabo I, Kappelmayer J, Alekseev SI, Ziskin MC. 2006. Millimeter wave induced reversible externalization of phosphatidylserine molecules in cells exposed in vitro. Bioelectromagnetics 27:233–244. Titushkin IA, Rao VS, Pickard WF, Moros EG, Shafirstein G, Cho MR. 2009. Altered calcium dynamics mediates P19-derived neuron-like cell responses to millimeter-wave radiation. Radiat Res 172:725–736. Wang S, Kaufman RJ. 2012. The impact of the unfolded protein response on human disease. J Cell Biol 197:857–867. Winer J, Jung CK, Shackel I, Williams PM. 1999. Development and validation of real-time quantitative reverse transcriptase-polymerase chain reaction for monitoring gene expression in cardiac myocytes in vitro. Anal Biochem 270: 41–49. Wu GW, Liu XX, Wu MX, Zhao JY, Chen WL, Lin RH, Lin JM. 2009. Experimental study of millimeter wave-induced differentiation of bone marrow mesenchymal stem cells into chondrocytes. Int J Mol Med 23:461–467. Xu X, Gupta S, Hu W, McGrath BC, Cavener DR. 2011. Hyperthermia induces the ER stress pathway. PLoS ONE 6: e23740. Yoshida H, Haze K, Yanagi H, Yura T, Mori K. 1998. Identification of the cis-acting endoplasmic reticulum stress response element responsible for transcriptional induction of mammalian glucose-regulated proteins. Involvement of basic leucine zipper transcription factors. J Biol Chem 273: 33741–33749. Zhadobov M, Sauleau R, Vié V, Himdi M, Le Coq L, Thouroude D. 2006. Interactions between 60 GHz millimeter waves and artificial biological membranes: Dependence on radiation parameters. IEEE Trans Microw Theory Tech 54: 2534–2542.

ER Stress Under MMW Exposure Zhadobov M, Nicolas Nicolaz C, Sauleau R, Desmots F, Thouroude D, Michel D, Le Dréan Y. 2009. Evaluation of the potential biological effects of the 60-GHz millimeter waves upon human cells. IEEE Trans Antennas Propag 57:2949–2956. Zhadobov M, Chahat N, Sauleau R, Le Quement C, Le Dréan Y. 2011. Millimeter-wave interactions with the human body: State of knowledge and recent advances. Int J Microw Wirless Technol 3:237–247.

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Zhadobov M, Sauleau R, Augustine R, Le Quément C, Le Dréan Y, Thouroude D. 2012. Near-field dosimetry for in vitro exposure of human cells at 60 GHz. Bioelectromagnetics 33:55–64. Zhu H, Guo FJ, Zhao W, Zhou J, Liu Y, Song F, Wang Y. 2012. ATF4 and IRE1a inhibit DNA repair protein DNAdependent protein kinase 1 induced by heat shock. Mol Cell Biochem 371:225–232.

Bioelectromagnetics

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

Emerging high data rate wireless communication systems, currently under development, will operate at millimeter waves (MMW) and specifically in the 60...
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