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Poque E, Ruigrok HJ, Arnaud-Cormos D, Habauzit D, Chappe Y, Martin C, De Gannes FP, Hurtier A, Garenne A, Lagroye I, Le Dréan Y, Lévêque P, Percherancier Y. Effects of radiofrequency field exposure on proteotoxic-induced and heat-induced HSF1 response in live cells using the bioluminescence resonance energy transfer technique. Cell Stress Chaperones 2021; 26:241-251. [PMID: 33067759 PMCID: PMC7736596 DOI: 10.1007/s12192-020-01172-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 10/09/2020] [Accepted: 10/12/2020] [Indexed: 01/09/2023] Open
Abstract
As of today, only acute effects of RF fields have been confirmed to represent a potential health hazard and they are attributed to non-specific heating (≥ 1 °C) under high-level exposure. Yet, the possibility that environmental RF impact living matter in the absence of temperature elevation needs further investigation. Since HSF1 is both a thermosensor and the master regulator of heat-shock stress response in eukaryotes, it remains to assess HSF1 activation in live cells under exposure to low-level RF signals. We thus measured basal, temperature-induced, and chemically induced HSF1 trimerization, a mandatory step on the cascade of HSF1 activation, under RF exposure to continuous wave (CW), Global System for Mobile (GSM), and Wi-Fi-modulated 1800 MHz signals, using a bioluminescence resonance energy transfer technique (BRET) probe. Our results show that, as expected, HSF1 is heat-activated by acute exposure of transiently transfected HEK293T cells to a CW RF field at a specific absorption rate of 24 W/kg for 30 min. However, we found no evidence of HSF1 activation under the same RF exposure condition when the cell culture medium temperature was fixed. We also found no experimental evidence that, at a fixed temperature, chronic RF exposure for 24 h at a SAR of 1.5 and 6 W/kg altered the potency or the maximal capability of the proteasome inhibitor MG132 to activate HSF1, whatever signal used. We only found that RF exposure to CW signals (1.5 and 6 W/kg) and GSM signals (1.5 W/kg) for 24 h marginally decreased basal HSF1 activity.
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Affiliation(s)
- Emmanuelle Poque
- CNRS, Bordeaux INP, CBMN laboratory, UMR5248, Bordeaux University, F-33607, Pessac, France
| | - Hermanus J Ruigrok
- CNRS, IMS laboratory, UMR5218, Bordeaux University, F-33400, Talence, France
| | - Delia Arnaud-Cormos
- CNRS, XLIM, UMR 7252, Limoges University, F-87000, Limoges, France
- Institut Universitaire de France (IUF), F-75005, Paris, France
| | - Denis Habauzit
- Institut de Recherche en Santé, Environnement et Travail (IRSET) - UMR_S 1085, Rennes University, F-35000, Rennes, France
| | - Yann Chappe
- CNRS, IMS laboratory, UMR5218, Bordeaux University, F-33400, Talence, France
| | - Catherine Martin
- Institut de Recherche en Santé, Environnement et Travail (IRSET) - UMR_S 1085, Rennes University, F-35000, Rennes, France
| | | | - Annabelle Hurtier
- CNRS, IMS laboratory, UMR5218, Bordeaux University, F-33400, Talence, France
| | - André Garenne
- CNRS, IMS laboratory, UMR5218, Bordeaux University, F-33400, Talence, France
| | - Isabelle Lagroye
- CNRS, IMS laboratory, UMR5218, Bordeaux University, F-33400, Talence, France
- Paris Sciences et Lettres Research University, F-75006, Paris, France
| | - Yves Le Dréan
- Institut de Recherche en Santé, Environnement et Travail (IRSET) - UMR_S 1085, Rennes University, F-35000, Rennes, France
| | - Philippe Lévêque
- CNRS, XLIM, UMR 7252, Limoges University, F-87000, Limoges, France
| | - Yann Percherancier
- CNRS, IMS laboratory, UMR5218, Bordeaux University, F-33400, Talence, France.
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Halgamuge MN, Skafidas E, Davis D. A meta-analysis of in vitro exposures to weak radiofrequency radiation exposure from mobile phones (1990-2015). ENVIRONMENTAL RESEARCH 2020; 184:109227. [PMID: 32199316 DOI: 10.1016/j.envres.2020.109227] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2020] [Revised: 01/29/2020] [Accepted: 02/03/2020] [Indexed: 06/10/2023]
Abstract
To function, mobile phone systems require transmitters that emit and receive radiofrequency signals over an extended geographical area exposing humans in all stages of development ranging from in-utero, early childhood, adolescents and adults. This study evaluates the question of the impact of radiofrequency radiation on living organisms in vitro studies. In this study, we abstract data from 300 peer-reviewed scientific publications (1990-2015) describing 1127 experimental observations in cell-based in vitro models. Our first analysis of these data found that out of 746 human cell experiments, 45.3% indicated cell changes, whereas 54.7% indicated no changes (p = 0.001). Realizing that there are profound distinctions between cell types in terms of age, rate of proliferation and apoptosis, and other characteristics and that RF signals can be characterized in terms of polarity, information content, frequency, Specific Absorption Rate (SAR) and power, we further refined our analysis to determine if there were some distinct properties of negative and positive findings associated with these specific characteristics. We further analyzed the data taking into account the cumulative effect (SAR × exposure time) to acquire the cumulative energy absorption of experiments due to radiofrequency exposure, which we believe, has not been fully considered previously. When the frequency of signals, length and type of exposure, and maturity, rate of growth (doubling time), apoptosis and other properties of individual cell types are considered, our results identify a number of potential non-thermal effects of radiofrequency fields that are restricted to a subset of specific faster-growing less differentiated cell types such as human spermatozoa (based on 19 reported experiments, p-value = 0.002) and human epithelial cells (based on 89 reported experiments, p-value < 0.0001). In contrast, for mature, differentiated adult cells of Glia (p = 0.001) and Glioblastoma (p < 0.0001) and adult human blood lymphocytes (p < 0.0001) there are no statistically significant differences for these more slowly reproducing cell lines. Thus, we show that RF induces significant changes in human cells (45.3%), and in faster-growing rat/mouse cell dataset (47.3%). In parallel with this finding, further analysis of faster-growing cells from other species (chicken, rabbit, pig, frog, snail) indicates that most undergo significant changes (74.4%) when exposed to RF. This study confirms observations from the REFLEX project, Belyaev and others that cellular response varies with signal properties. We concur that differentiation of cell type thus constitutes a critical piece of information and should be useful as a reference for many researchers planning additional studies. Sponsorship bias is also a factor that we did not take into account in this analysis.
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Affiliation(s)
- Malka N Halgamuge
- Department Department of Electrical and Electronic Engineering, The University of Melbourne, Parkville, VIC, 3010, Australia.
| | - Efstratios Skafidas
- Department Department of Electrical and Electronic Engineering, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Devra Davis
- Environmental Health Trust, Teton Village, WY, 83025, USA
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3
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Manna D, Ghosh R. Effect of radiofrequency radiation in cultured mammalian cells: A review. Electromagn Biol Med 2016; 35:265-301. [PMID: 27053138 DOI: 10.3109/15368378.2015.1092158] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The use of mobile phone related technologies will continue to increase in the foreseeable future worldwide. This has drawn attention to the probable interaction of radiofrequency electromagnetic radiation with different biological targets. Studies have been conducted on various organisms to evaluate the alleged ill-effect on health. We have therefore attempted to review those work limited to in vitro cultured cells where irradiation conditions were well controlled. Different investigators have studied varied endpoints like DNA damage, cell cycle arrest, reactive oxygen species (ROS) formation, cellular morphology and viability to weigh the genotoxic effect of such radiation by utilizing different frequencies and dose rates under various irradiation conditions that include continuous or pulsed exposures and also amplitude- or frequency-modulated waves. Cells adapt to change in their intra and extracellular environment from different chemical and physical stimuli through organized alterations in gene or protein expression that result in the induction of stress responses. Many studies have focused on such effects for risk estimations. Though the effects of microwave radiation on cells are often not pronounced, some investigators have therefore combined radiofrequency radiation with other physical or chemical agents to observe whether the effects of such agents were augmented or not. Such reports in cultured cellular systems have also included in this review. The findings from different workers have revealed that, effects were dependent on cell type and the endpoint selection. However, contradictory findings were also observed in same cell types with same assay, in such cases the specific absorption rate (SAR) values were significant.
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Affiliation(s)
- Debashri Manna
- a Department of Biochemistry & Biophysics , University of Kalyani , Kalyani , India
| | - Rita Ghosh
- a Department of Biochemistry & Biophysics , University of Kalyani , Kalyani , India
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Gao Y, Lu Y, Yi J, Li Z, Gao D, Yu Z, Wu T, Zhang C. A Genome-Wide mRNA Expression Profile in Caenorhabditis elegans under Prolonged Exposure to 1750MHz Radiofrequency Fields. PLoS One 2016; 11:e0147273. [PMID: 26811916 PMCID: PMC4727783 DOI: 10.1371/journal.pone.0147273] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2015] [Accepted: 12/31/2015] [Indexed: 01/06/2023] Open
Abstract
OBJECTIVE C. elegans has been used as a biomonitor for microwave-induced stress. However, the RF (radiofrequency) fields that have been used in previous studies were weak (≤1.8W/kg), and the bio-effects on C. elegans were mostly negative or ambiguous. Therefore, this study used more intense RF fields (SAR = 3W/kg) and longer time course of exposure (60h at 25°C, L1 stage through adult stage) to investigate the biological consequences of 1750 MHz RF fields in wild-type worms. METHODS The growth rates and lifespans of RF-exposure group and the control group were carefully recorded. RNA samples were collected at L4 (35h) and gravid adult (50h) stages for further high-throughput sequencing, focusing on differences between the RF-exposure and the sham control groups. RESULTS The RF-exposed and sham control groups developed at almost the same rate and had similar longevity curves. In L4 stage worms, 94 up-regulated and 17 down-regulated genes were identified, while 186 up-regulated and 3 down-regulated genes were identified in adult stage worms. GO analysis showed that the differentially expressed genes at 35h were associated with growth, body morphogenesis and collagen and cuticle-based development. Genes that were linked to growth rate and reproductive development were differentially expressed at 50h. Some embryonic and larval development genes in the offspring were also differentially expressed at 50h. Ten genes were differentially expressed at both 35h and 50h, most of which were involved in both embryonic and larval developmental processes. Although prolonged RF fields did not induce significant temperature increase in RF exposure groups, the temperature inside worms during exposure was unknown. CONCLUSIONS No harmful effects were observed in prolonged exposure to 1750 MHz RF fields at SAR of 3W/kg on development and longevity of C. elegans. Although some differentially expressed genes were found after prolonged RF exposure, these differences were ascribed to oscillating gene expression patterns in L4 and gravid adult worms. It was also difficult to rule out a weak thermal effect caused by prolonged RF exposure inside the worms.
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Affiliation(s)
- Yan Gao
- Beijing Institute of Radiation Medicine, Cognitive and Mental Health Research Center, State Key Laboratory of Proteomics, State Key Laboratory of Millimeter Wave, Beijing, 100850, China
| | - Yiming Lu
- Beijing Institute of Radiation Medicine, Cognitive and Mental Health Research Center, State Key Laboratory of Proteomics, State Key Laboratory of Millimeter Wave, Beijing, 100850, China
| | - Jianming Yi
- Beijing Institute of Radiation Medicine, Cognitive and Mental Health Research Center, State Key Laboratory of Proteomics, State Key Laboratory of Millimeter Wave, Beijing, 100850, China
| | - Zhihui Li
- Beijing Institute of Radiation Medicine, Cognitive and Mental Health Research Center, State Key Laboratory of Proteomics, State Key Laboratory of Millimeter Wave, Beijing, 100850, China
| | - Dawen Gao
- Beijing Institute of Radiation Medicine, Cognitive and Mental Health Research Center, State Key Laboratory of Proteomics, State Key Laboratory of Millimeter Wave, Beijing, 100850, China
| | - Zhoulong Yu
- Beijing Institute of Radiation Medicine, Cognitive and Mental Health Research Center, State Key Laboratory of Proteomics, State Key Laboratory of Millimeter Wave, Beijing, 100850, China
| | - Tongning Wu
- China Academy of Telecommunication Research of Ministry of Industry and Information Technology, No. 52 Huayuanbei Road, Beijing, 100191, China
| | - Chenggang Zhang
- Beijing Institute of Radiation Medicine, Cognitive and Mental Health Research Center, State Key Laboratory of Proteomics, State Key Laboratory of Millimeter Wave, Beijing, 100850, China
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Targeting the heat shock response in combination with radiotherapy: Sensitizing cancer cells to irradiation-induced cell death and heating up their immunogenicity. Cancer Lett 2015; 368:209-29. [DOI: 10.1016/j.canlet.2015.02.047] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2014] [Revised: 02/22/2015] [Accepted: 02/26/2015] [Indexed: 12/16/2022]
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Abstract
The heat shock response (HSR) is an ancient and highly conserved process that is essential for coping with environmental stresses, including extremes of temperature. Fever is a more recently evolved response, during which organisms temporarily subject themselves to thermal stress in the face of infections. We review the phylogenetically conserved mechanisms that regulate fever and discuss the effects that febrile-range temperatures have on multiple biological processes involved in host defense and cell death and survival, including the HSR and its implications for patients with severe sepsis, trauma, and other acute systemic inflammatory states. Heat shock factor-1, a heat-induced transcriptional enhancer is not only the central regulator of the HSR but also regulates expression of pivotal cytokines and early response genes. Febrile-range temperatures exert additional immunomodulatory effects by activating mitogen-activated protein kinase cascades and accelerating apoptosis in some cell types. This results in accelerated pathogen clearance, but increased collateral tissue injury, thus the net effect of exposure to febrile range temperature depends in part on the site and nature of the pathologic process and the specific treatment provided.
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Affiliation(s)
- Jeffrey D Hasday
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, University of Maryland School of Medicine and the Baltimore V.A. Medical Center, Baltimore, Maryland
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7
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Abstract
The heat shock response is a highly conserved primitive response that is essential for survival against a wide range of stresses, including extremes of temperature. Fever is a more recently evolved response, during which organisms raise their core body temperature and temporarily subject themselves to thermal stress in the face of infections. The present review documents studies showing the potential overlap between the febrile response and the heat shock response and how both activate the same common transcriptional programme (although with different magnitudes) including the stress-activated transcription factor, heat shock factor-1, to modify host defences in the context of infection, inflammation and injury. The review focuses primarily on how hyperthermia within the febrile range that often accompanies infections and inflammation acts as a biological response modifier and modifies innate immune responses. The characteristic 2-3 °C increase in core body temperature during fever activates and utilises elements of the heat shock response pathway to modify cytokine and chemokine gene expression, cellular signalling and immune cell mobilisation to sites of inflammation, infection and injury. Interestingly, typical proinflammatory agonists such as Toll-like receptor agonists modify the heat shock-induced transcriptional programme and expression of HSP genes following co-exposure to febrile range hyperthermia or heat shock, suggesting a complex reciprocal regulation between the inflammatory pathway and the heat shock response pathway.
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Affiliation(s)
- Ishwar S Singh
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, USA.
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Terro F, Magnaudeix A, Crochetet M, Martin L, Bourthoumieu S, Wilson CM, Yardin C, Leveque P. GSM-900MHz at low dose temperature-dependently downregulates α-synuclein in cultured cerebral cells independently of chaperone-mediated-autophagy. Toxicology 2012; 292:136-44. [PMID: 22185909 DOI: 10.1016/j.tox.2011.12.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2011] [Revised: 11/09/2011] [Accepted: 12/05/2011] [Indexed: 12/24/2022]
Abstract
The expanding use of GSM devices has resulted in public concern. Chaperone-mediated autophagy (CMA) is a way for protein degradation in the lysosomes and increases under stress conditions as a cell defense response. α-synuclein, a CMA substrate, is a component of Parkinson disease. Since GSM might constitute a stress signal, we raised the possibility that GSM could alter the CMA process. Here, we analyzed the effects of chronic exposure to a low GSM-900MHz dose on apoptosis and CMA. Cultured cerebral cortical cells were sham-exposed or exposed to GSM-900MHz at specific absorption rate (SAR): 0.25W/kg for 24 h using a wire-patch cell. Apoptosis was analyzed by DAPI stain of the nuclei and western blot of cleaved caspase-3. The expression of proteins involved in CMA (HSC70, HSP40, HSP90 and LAMP-2A) and α-synuclein were analyzed by western blot. CMA was also quantified in situ by analyzing the cell localization of active lysosomes. 24 h exposure to GSM-900MHz resulted in ∼0.5°C temperature rise. It did not induce apoptosis but increased HSC70 by 26% and slightly decreased HSP90 (<10%). It also decreased α-synuclein by 24% independently of CMA, since the localization of active lysosomes was not altered. Comparable effects were observed in cells incubated at 37.5°C, a condition that mimics the GSM-generated temperature rise. The GSM-induced changes in HSC70, HSP90 and α-synuclein are most likely linked to temperature rise. We did not observe any immediate effect on cell viability. However, the delayed and long term consequences (protective or deleterious) of these changes on cell fate should be examined.
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Affiliation(s)
- Faraj Terro
- Groupe de Neurobiologie Cellulaire - EA3842 Homéostasie cellulaire et pathologies, Faculté de Médecine, 2 rue du Dr Raymond Marcland, 87025 Limoges Cedex, France.
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9
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Marino C, Lagroye I, Scarfì MR, Sienkiewicz Z. Are the young more sensitive than adults to the effects of radiofrequency fields? An examination of relevant data from cellular and animal studies. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2011; 107:374-85. [DOI: 10.1016/j.pbiomolbio.2011.09.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2011] [Accepted: 09/01/2011] [Indexed: 10/17/2022]
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Juutilainen J, Höytö A, Kumlin T, Naarala J. Review of possible modulation-dependent biological effects of radiofrequency fields. Bioelectromagnetics 2011; 32:511-34. [PMID: 21480304 DOI: 10.1002/bem.20652] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2010] [Accepted: 01/04/2011] [Indexed: 12/13/2022]
Affiliation(s)
- Jukka Juutilainen
- Department of Environmental Science, University of Eastern Finland, Kuopio, Finland.
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11
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McNamee JP, Chauhan V. Radiofrequency Radiation and Gene/Protein Expression: A Review. Radiat Res 2009; 172:265-87. [DOI: 10.1667/rr1726.1] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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12
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Tulapurkar ME, Asiegbu BE, Singh IS, Hasday JD. Hyperthermia in the febrile range induces HSP72 expression proportional to exposure temperature but not to HSF-1 DNA-binding activity in human lung epithelial A549 cells. Cell Stress Chaperones 2009; 14:499-508. [PMID: 19221897 PMCID: PMC2728283 DOI: 10.1007/s12192-009-0103-3] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2008] [Revised: 01/26/2009] [Accepted: 01/29/2009] [Indexed: 10/21/2022] Open
Abstract
Expression of heat shock proteins (HSPs) is classically activated at temperatures above the physiologic range (>or=42 degrees C) via activation of the stress-activated transcription factor, heat shock factor-1 (HSF-1). Several studies suggest that less extreme hyperthermia, especially within the febrile range, as occurs during fever and exertional/environmental hyperthemia, can also activate HSF-1 and enhance HSP expression. We compared HSP72 protein and mRNA expression in human A549 lung epithelial cells continuously exposed to 38.5 degrees C, 39.5 degrees C, or 41 degrees C or exposed to a classic heat shock (42 degrees C for 2 h). We found that expression of HSP72 protein and mRNA increased linearly as incubation temperature was increased from 37 degrees C to 41 degrees C, but increased abruptly when the incubation temperature was raised to 42 degrees C. A similar response in luciferase activity was observed using A549 cells stably transfected with an HSF-1-responsive luciferase reporter plasmid. However, activation of intranuclear HSF-1 DNA-binding activity was comparable at 38.5 degrees C, 39.5 degrees C, and 41 degrees C and only modestly greater at 42 degrees C but the mobility of HSF1 protein on a denaturing gel was altered with increasing exposure temperature and was distinctly different at 42 degrees C. These findings indicate that the proportional changes in HSF-1-dependent HSP72 expression at febrile-range temperatures are dependent upon exposure time and temperature but not on the degree of HSF-1 DNA-binding activity. Instead, HSF-1-mediated HSP expression following hyperthermia and heat shock appears to be mediated, in addition to HSF-1 activation, by posttranslational modifications of HSF-1 protein.
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Affiliation(s)
- Mohan E. Tulapurkar
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, School of Medicine, University of Maryland, Baltimore, MD 21201 USA
| | - Benedict E. Asiegbu
- Division of Neonatology, Department of Pediatrics, School of Medicine, University of Maryland, Baltimore, MD 21201 USA
| | - Ishwar S. Singh
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, School of Medicine, University of Maryland, Baltimore, MD 21201 USA
- Mucosal Biology Research Center, School of Medicine, University of Maryland, Baltimore, MD 21201 USA
- Research Services, Baltimore VA Medical Center, Baltimore, MD USA
| | - Jeffrey D. Hasday
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, School of Medicine, University of Maryland, Baltimore, MD 21201 USA
- Mucosal Biology Research Center, School of Medicine, University of Maryland, Baltimore, MD 21201 USA
- Research Services, Baltimore VA Medical Center, Baltimore, MD USA
- Health Science Facility-II, School of Medicine, University of Maryland, Rm. 327, 20 Penn St., Baltimore, MD 21201 USA
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Vanderwaal RP, Cha B, Moros EG, Roti Roti JL. HSP27 phosphorylation increases after 45°C or 41°C heat shocks but not after non-thermal TDMA or GSM exposures. Int J Hyperthermia 2009; 22:507-19. [PMID: 16971370 DOI: 10.1080/02656730600924406] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
Abstract
PURPOSE Experiments with cultured HeLa, S3 and E.A. Hy296 cells were performed to determine if exposure to acute (30 min at 45 degrees C) or chronic (2 h at 41 degrees C) heat shocks or to non-thermal exposures of radiofrequency radiation (RF) induce changes in HSP27 phosphorylation. MATERIALS AND METHODS The radiofrequency (RF) exposures used in this study were 847 MHz time division multiple access modulated (TDMA) at a specific absorption rate (SAR) of 5 W kg-1 for 1, 2 or 24 h or 900 MHz GSM modulated (GSM) at a SAR of 3.7 W kg-1 for 1, 2 or 5 h. HSP27 phosphorylation was evaluated by resolving the various phosphorylation forms using two-dimensional gel electrophoresis measuring the relative amount of each by densitometry. Alternatively, an antibody specific for phosphorylated HSP27 was used to detect changes in HSP27 phosphorylation levels. All heat shock and RF exposure conditions were analysed simultaneously along with a matched incubator control sample. Each experiment was repeated three times. RESULTS Following heat shock, the degree of phosphorylation of HSP27 varied with the heat dose, with acute hyperthermia (45 degrees C) having an increased proportion of higher phosphorylated forms. Exposure of HeLa S3 cells to 5 W kg-1 TDMA for 1, 2 or 24 h did not induce significant differences in the levels of HSP27 phosphorylation compared to incubator control or sham. Exposure of E.A. Hy926 cells to 3.7 W kg-1 900 MHz GSM for 1, 2 or 5 h did not induce significant differences in the levels of HSP27 phosphorylation compared to sham exposed. CONCLUSIONS Acute and moderate hyperthermia significantly increase HSP27 phosphorylation, but there was no significant change in the levels of HSP27 following non-thermal exposure to TDMA and GSM modulated RF radiations.
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Affiliation(s)
- Robert P Vanderwaal
- Department of Radiation Oncology, Washington University School of Medicine, St Louis, MO 63108, USA
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14
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Sontag W, Kruglikov IL. Expression of heat shock proteins after ultrasound exposure in HL-60 cells. ULTRASOUND IN MEDICINE & BIOLOGY 2009; 35:1032-1041. [PMID: 19285782 DOI: 10.1016/j.ultrasmedbio.2008.12.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2008] [Revised: 12/15/2008] [Accepted: 12/16/2008] [Indexed: 05/27/2023]
Abstract
One of the important cellular defense mechanisms against stress is the induction of heat shock proteins (HSPs). We have recently demonstrated that a low frequency electromagnetic field is unable to induce the heat shock response (HSR). In the present study, we expanded our investigations to the induction of HSPs, particularly Hsp72, by ultrasound (US). Human promyelocytic leukemia HL-60 cells were exposed in suspension to US at 1, 3 and 10 MHz, as well as combinations of two of these frequencies. The ability of US to induce Hsp72 was tested for different frequencies, intensities and exposure times. In addition, the water bath temperature was varied from 30 to 36 degrees C. The Hsp72 protein expression was determined 4 and 24 h after treatment. We found that the amount of Hsp72 increased with increasing US frequency, reaching its highest level of about 1800%, induced by 10 MHz. After increasing the temperature of the water bath, the amount of Hsp72 in the treated cells was also increased, whereas no induction was observed at 30 degrees C. For all treatment conditions, ultrasound of 1 MHz was unable to significantly induce Hsp72. At 10 MHz, the exposure time was varied from 0 to 20 min. We found that the induction of Hsp72 took place after 5 min of exposure. For a fixed level of absorbed US energy, the continuous regime, as well as a pulsation of 1:2 (5 ms on and 5 ms off) induced the same Hsp72 level. Pulsation of 1:5 (2 ms on and 8 ms off) and 1:10 (1 ms on and 9 ms off) did not show any effect. A single sonication of 20 min, as well as a fractionated sonication of two 10 min exposures induced the same level of Hsp72, whereas four exposures of 5 min reduced the Hsp72 level. At the optimum exposure conditions (10 MHz, 10 min), the concentration of other HSPs was also determined. Hsp27 showed no effect but Hsp32, Hsp40 and Hsp72 were induced. Taken together, these results suggest a synergistic interaction between heat and US.
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Affiliation(s)
- Werner Sontag
- Institut für Biologische Grenzflächen, Forschungszentrum Karlsruhe, Karlsruhe, Germany.
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15
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Habash RWY, Elwood JM, Krewski D, Lotz WG, McNamee JP, Prato FS. Recent advances in research on radiofrequency fields and health: 2004-2007. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART B, CRITICAL REVIEWS 2009; 12:250-288. [PMID: 20183523 DOI: 10.1080/10937400903094125] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The widespread use of wireless telecommunications devices, particularly mobile phones and wireless networks, has resulted in increased human exposure to radiofrequency (RF) fields. Although national and international agencies have established safety guidelines for exposure to RF fields, concerns remain about the potential for adverse health outcomes to occur in relation to RF field exposure. The extensive literature on RF fields and health was reviewed by a number of authorities, including the Royal Society of Canada (1999). This report is the third in a series of updates to the original report of the Royal Society of Canada, covering the period 2004-2007. In particular, the present study examined new data on (1) dosimetry and exposure assessment, (2) biological effects of RF fields such as enzyme induction, and (3) toxicological effects, including genotoxicity and carcinogenicity. Epidemiological studies of the potential health effects of RF exposure, particularly from mobile phones, were determined, along with human and animal studies of neurological and behavioural effects. Within the last 4 yrs investigators concluded that there is no clear evidence of adverse health effects associated with RF fields, although continued research is recommended to address specific areas of concern, including exposure to RF fields among children using mobile phones. The results of the ongoing 13-country World Health Organization INTERPHONE study of mobile phones may provide important new information on the potential cancer risks associated with mobile phone use.
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Affiliation(s)
- Riadh W Y Habash
- R. Samuel McLaughlin Center for Population Health Risk Assessment, University of Ottawa, Ottawa, Ontario, Canada.
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16
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Makker K, Varghese A, Desai NR, Mouradi R, Agarwal A. Cell phones: modern man's nemesis? Reprod Biomed Online 2009; 18:148-57. [DOI: 10.1016/s1472-6483(10)60437-3] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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17
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Singh IS, Shah NG, Almutairy E, Hasday JD. Role of HSF1 in Infectious Disease. HEAT SHOCK PROTEINS 2009. [DOI: 10.1007/978-90-481-2976-8_1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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18
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Vanderstraeten J, Verschaeve L. Gene and protein expression following exposure to radiofrequency fields from mobile phones. ENVIRONMENTAL HEALTH PERSPECTIVES 2008; 116:1131-1135. [PMID: 18795152 PMCID: PMC2535611 DOI: 10.1289/ehp.11279] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2008] [Accepted: 05/09/2008] [Indexed: 05/26/2023]
Abstract
BACKGROUND Since 1999, several articles have been published on genome-wide and/or proteome-wide response after exposure to radiofrequency (RF) fields whose signal and intensities were similar to or typical of those of currently used mobile telephones. These studies were performed using powerful high-throughput screening techniques (HTSTs) of transcriptomics and/or proteomics, which allow for the simultaneous screening of the expression of thousands of genes or proteins. OBJECTIVES We reviewed these HTST-based studies and compared the results with currently accepted concepts about the effects of RF fields on gene expression. In this article we also discuss these last in light of the recent concept of microwave-assisted chemistry. DISCUSSION To date, the results of HTST-based studies of transcriptomics and/or proteomics after exposure to RF fields relevant to human exposure are still inconclusive, as most of the positive reports are flawed by methodologic imperfections or shortcomings. In addition, when positive findings were reported, no precise response pattern could be identified in a reproducible way. In particular, results from HTST studies tend to exclude the role of a cell stressor for exposure to RF fields at nonthermal intensities. However, on the basis of lessons from microwave-assisted chemistry, we can assume that RF fields might affect heat-sensitive gene or protein expression to an extent larger than would be predicted from temperature change only. But in all likelihood, this would concern intensities higher than those relevant to usual human exposure. CONCLUSIONS The precise role of transcriptomics and proteomics in the screening of bioeffects from exposure to RF fields from mobile phones is still uncertain in view of the lack of positively identified phenotypic change and the lack of theoretical, as well as experimental, arguments for specific gene and/or protein response patterns after this kind of exposure.
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Affiliation(s)
- Jacques Vanderstraeten
- Research Unit on Work Health and Environmental Toxicology, School of Public Health, Université Libre de Bruxelles, Brussels, Belgium.
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Takebayashi T, Varsier N, Kikuchi Y, Wake K, Taki M, Watanabe S, Akiba S, Yamaguchi N. Mobile phone use, exposure to radiofrequency electromagnetic field, and brain tumour: a case-control study. Br J Cancer 2008; 98:652-9. [PMID: 18256587 PMCID: PMC2243154 DOI: 10.1038/sj.bjc.6604214] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
In a case–control study in Japan of brain tumours in relation to mobile phone use, we used a novel approach for estimating the specific absorption rate (SAR) inside the tumour, taking account of spatial relationships between tumour localisation and intracranial radiofrequency distribution. Personal interviews were carried out with 88 patients with glioma, 132 with meningioma, and 102 with pituitary adenoma (322 cases in total), and with 683 individually matched controls. All maximal SAR values were below 0.1 W kg−1, far lower than the level at which thermal effects may occur, the adjusted odds ratios (ORs) for regular mobile phone users being 1.22 (95% confidence interval (CI): 0.63–2.37) for glioma and 0.70 (0.42–1.16) for meningioma. When the maximal SAR value inside the tumour tissue was accounted for in the exposure indices, the overall OR was again not increased and there was no significant trend towards an increasing OR in relation to SAR-derived exposure indices. A non-significant increase in OR among glioma patients in the heavily exposed group may reflect recall bias.
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Affiliation(s)
- T Takebayashi
- Department of Preventive Medicine and Public Health, Keio University School of Medicine, Tokyo, Japan
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20
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Dawe AS, Nylund R, Leszczynski D, Kuster N, Reader T, De Pomerai DI. Continuous wave and simulated GSM exposure at 1.8 W/kg and 1.8 GHz do not inducehsp16-1 heat-shock gene expression inCaenorhabditis elegans. Bioelectromagnetics 2008; 29:92-9. [PMID: 17902155 DOI: 10.1002/bem.20366] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Recent data suggest that there might be a subtle thermal explanation for the apparent induction by radiofrequency (RF) radiation of transgene expression from a small heat-shock protein (hsp16-1) promoter in the nematode, Caenorhabditis elegans. The RF fields used in the C. elegans study were much weaker (SAR 5-40 mW kg(-1)) than those routinely tested in many other published studies (SAR approximately 2 W kg(-1)). To resolve this disparity, we have exposed the same transgenic hsp16-1::lacZ strain of C. elegans (PC72) to higher intensity RF fields (1.8 GHz; SAR approximately 1.8 W kg(-1)). For both continuous wave (CW) and Talk-pulsed RF exposures (2.5 h at 25 degrees C), there was no indication that RF exposure could induce reporter expression above sham control levels. Thus, at much higher induced RF field strength (close to the maximum permitted exposure from a mobile telephone handset), this particular nematode heat-shock gene is not up-regulated. However, under conditions where background reporter expression was moderately elevated in the sham controls (perhaps as a result of some unknown co-stressor), we found some evidence that reporter expression may be reduced by approximately 15% following exposure to either Talk-pulsed or CW RF fields.
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Affiliation(s)
- Adam S Dawe
- Institute of Genetics, School of Biology, University of Nottingham, University Park, Nottingham, United Kingdom
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21
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Chauhan V, Qutob SS, Lui S, Mariampillai A, Bellier PV, Yauk CL, Douglas GR, Williams A, McNamee JP. Analysis of gene expression in two human-derived cell lines exposedin vitro to a 1.9 GHz pulse-modulated radiofrequency field. Proteomics 2007; 7:3896-905. [PMID: 17902192 DOI: 10.1002/pmic.200700215] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
There is considerable controversy surrounding the biological effects of radiofrequency (RF) fields, as emitted by mobile phones. Previous work from our laboratory has shown no effect related to the exposure of 1.9 GHz pulse-modulated RF fields on the expression of 22,000 genes in a human glioblastoma-derived cell-line (U87MG) at 6 h following a 4 h RF field exposure period. As a follow-up to this study, we have now examined the effect of RF field exposure on the possible expression of late onset genes in U87MG cells after a 24 h RF exposure period. In addition, a human monocyte-derived cell-line (Mono-Mac-6, MM6) was exposed to intermittent (5 min ON, 10 min OFF) RF fields for 6 h and then gene expression was assessed immediately after exposure and at 18 h postexposure. Both cell lines were exposed to 1.9 GHz pulse-modulated RF fields for 6 or 24 h at specific absorption rates (SARs) of 0.1-10.0 W/kg. In support of our previous results, we found no evidence that nonthermal RF field exposure could alter gene expression in either cultured U87MG or MM6 cells, relative to nonirradiated control groups. However, exposure of both cell-lines to heat-shock conditions (43 degrees C for 1 h) caused an alteration in the expression of a number of well-characterized heat-shock proteins.
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Affiliation(s)
- Vinita Chauhan
- Consumer and Clinical Radiation Protection Bureau, Healthy Environments and Consumer Safety Branch, Health Canada, Ottawa, Ontario, Canada
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22
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Sanchez S, Haro E, Ruffié G, Veyret B, Lagroye I. In vitro study of the stress response of human skin cells to GSM-1800 mobile phone signals compared to UVB radiation and heat shock. Radiat Res 2007; 167:572-80. [PMID: 17474794 DOI: 10.1667/rr0802.1] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2006] [Accepted: 11/13/2006] [Indexed: 11/03/2022]
Abstract
The evolution of mobile phone technology is toward an increase of the carrier frequency up to 2.45 GHz. Absorption of radiofrequency (RF) radiation becomes more superficial as the frequency increases. This increasingly superficial absorption of RF radiation by the skin, which is the first organ exposed to RF radiation, may lead to stress responses in skin cells. We thus investigated the expression of three heat-shock proteins (HSP70, HSC70, HSP27) using immunohistochemistry and induction of apoptosis by flow cytometry on human primary keratinocytes and fibroblasts. A well-characterized exposure system, SXC 1800, built by the IT'IS foundation was used at 1800 MHz, with a 217 Hz modulation. We tested a 48-h exposure at an SAR of 2 W/kg (ICNIRP local exposure limit). Skin cells were also irradiated with a 600 mJ/cm2 single dose of UVB radiation and subjected to heat shock (45 degrees C, 20 min) as positive controls for apoptosis and HSP expression, respectively. The results showed no effect of a 48-h GSM-1800 exposure at 2 W/kg on either keratinocytes or fibroblasts, in contrast to UVB-radiation or heat-shock treatments, which injured cells. We thus conclude that the GSM-1800 signal does not act as a stress factor on human primary skin cells in vitro.
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Affiliation(s)
- S Sanchez
- University of Bordeaux 1, IMS Laboratory, UMR 5218 CNRS, EPHE Bioelectromagnetics Group, Pessac, France.
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Foster KR, Glaser R. Thermal mechanisms of interaction of radiofrequency energy with biological systems with relevance to exposure guidelines. HEALTH PHYSICS 2007; 92:609-20. [PMID: 17495663 DOI: 10.1097/01.hp.0000262572.64418.38] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
This article reviews thermal mechanisms of interaction between radiofrequency (RF) fields and biological systems, focusing on theoretical frameworks that are of potential use in setting guidelines for human exposure to RF energy. Several classes of thermal mechanisms are reviewed that depend on the temperature increase or rate of temperature increase and the relevant dosimetric considerations associated with these mechanisms. In addition, attention is drawn to possible molecular and physiological reactions that could be induced by temperature elevations below 0.1 degrees, which are normal physiological responses to heat, and to the so-called microwave auditory effect, which is a physiologically trivial effect resulting from thermally-induced acoustic stimuli. It is suggested that some reported "nonthermal" effects of RF energy may be thermal in nature; also that subtle thermal effects from RF energy exist but have no consequence to health or safety. It is proposed that future revisions of exposure guidelines make more explicit use of thermal models and empirical data on thermal effects in quantifying potential hazards of RF fields.
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Affiliation(s)
- Kenneth R Foster
- University of Pennsylvania, Department of Bioengineering, Philadelphia, PA 19104, USA.
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24
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Whitehead TD, Moros EG, Brownstein BH, Roti Roti JL. The number of genes changing expression after chronic exposure to Code Division Multiple Access or Frequency DMA radiofrequency radiation does not exceed the false-positive rate. Proteomics 2006; 6:4739-44. [PMID: 16933338 DOI: 10.1002/pmic.200600051] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Experiments with cultured C3H 10T 1/2 cells were performed to determine if exposure to cell phone radiofrequency (RF) radiations induce changes in gene expression. Following a 24 h exposure of 5 W/kg specific adsorption rate, RNA was extracted from the exposed and sham control cells for microarray analysis on Affymetrix U74Av2 Genechips. Cells exposed to 0.68 Gy of X-rays with a 4-h recovery were used as positive controls. The number of gene expression changes induced by RF radiation was not greater than the number of false positives expected based on a sham versus sham comparison. In contrast, the X-irradiated samples showed higher numbers of probe sets changing expression level than in the sham versus sham comparison.
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Affiliation(s)
- Timothy D Whitehead
- Department of Radiation Oncology, Washington University School of Medicine, St. Louis, MO 63108, USA
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Chauhan V, Mariampillai A, Gajda GB, Thansandote A, McNamee JP. Analysis of proto-oncogene and heat-shock protein gene expression in human derived cell-lines exposed in vitro to an intermittent 1.9 GHz pulse-modulated radiofrequency field. Int J Radiat Biol 2006; 82:347-54. [PMID: 16782652 DOI: 10.1080/09553000600771549] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
PURPOSE Several studies have reported that radiofrequency (RF) fields, as emitted by mobile phones, may cause changes in gene expression in cultured human cell-lines. The current study was undertaken to evaluate this possibility in two human-derived immune cell-lines. MATERIALS AND METHODS HL-60 and Mono-Mac-6 (MM6) cells were individually exposed to intermittent (5 min on, 10 min off) 1.9 GHz pulse-modulated RF fields at a average specific absorption rate (SAR) of 1 and 10 W/kg at 37 +/- 0.5 degrees C for 6 h. Concurrent negative and positive (heat-shock for 1 h at 43 degrees C) controls were conducted with each experiment. Immediately following RF field exposure (T = 6 h) and 18 h post-exposure (T = 24 h), cell pellets were collected from each of the culture dishes and analyzed for transcript levels of proto-oncogenes (c-jun, c-myc and c-fos) and the stress-related genes (heat shock proteins (HSP) HSP27 and HSP70B) by quantitative reverse transcriptase polymerase chain reaction (RT-PCR). RESULTS No significant effects were observed in mRNA expression of HSP27, HSP70, c-jun, c-myc or c-fos between the sham and RF-exposed groups, in either of the two cell-lines. However, the positive (heat-shock) control group displayed a significant elevation in the expression of HSP27, HSP70, c-fos and c-jun in both cell-lines at T = 6 and 24 h, relative to the sham and negative control groups. CONCLUSION This study found no evidence that exposure of cells to non-thermalizing levels of 1.9 GHz pulse-modulated RF fields can cause any detectable change in stress-related gene expression.
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Affiliation(s)
- Vinita Chauhan
- Consumer and Clinical Radiation Protection Bureau, Healthy Environment and Consumer Safety Branch, Health Canada, Ottawa, Ontario, Canada
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Rockwell S, Kimler BF, Moulder JE. Publishing negative results: the problem of publication bias. Radiat Res 2006; 165:623-5. [PMID: 16802861 DOI: 10.1667/rr3573.1] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Qutob SS, Chauhan V, Bellier PV, Yauk CL, Douglas GR, Berndt L, Williams A, Gajda GB, Lemay E, Thansandote A, McNamee JP. Microarray Gene Expression Profiling of a Human Glioblastoma Cell Line ExposedIn Vitroto a 1.9 GHz Pulse-Modulated Radiofrequency Field. Radiat Res 2006; 165:636-44. [PMID: 16802863 DOI: 10.1667/rr3561.1] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The widespread use of mobile phones has led to public concerns about the health effects associated with exposure to radiofrequency (RF) fields. The paramount concern of most persons relates to the potential of these fields to cause cancer. Unlike ionizing radiation, RF fields used for mobile telecommunications (800-1900 MHz) do not possess sufficient energy to directly damage DNA. Most rodent bioassay and in vitro genotoxicity/mutation studies have reported that RF fields at non-thermal levels have no direct mutagenic, genotoxic or carcinogenic effects. However, some evidence has suggested that RF fields may cause detectable postexposure changes in gene expression. Therefore, the purpose of this study was to assess the ability of exposure to a 1.9 GHz pulse-modulated RF field for 4 h at specific absorption rates (SARs) of 0.1, 1.0 and 10.0 W/kg to affect global gene expression in U87MG glioblastoma cells. We found no evidence that non-thermal RF fields can affect gene expression in cultured U87MG cells relative to the nonirradiated control groups, whereas exposure to heat shock at 43 degrees C for 1 h up-regulated a number of typical stress-responsive genes in the positive control group. Future studies will assess the effect of RF fields on other cell lines and on gene expression in the mouse brain after in vivo exposure.
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Affiliation(s)
- S S Qutob
- Consumer and Clinical Radiation Protection Bureau, Healthy Environment and Consumer Safety Branch, Health Canada, Ottawa, Ontario, Canada, K1A 1C1
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Whitehead TD, Moros EG, Brownstein BH, Roti Roti JL. Gene Expression does not Change Significantly in C3H 10T½ Cells after Exposure to 847.74 CDMA or 835.62 FDMA Radiofrequency Radiation. Radiat Res 2006; 165:626-35. [PMID: 16802862 DOI: 10.1667/rr3560.1] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
In vitro experiments with C3H 10T(1/2) mouse cells were performed to determine whether Frequency Division Multiple Access (FDMA) or Code Division Multiple Access (CDMA) modulated radiofrequency (RF) radiations induce changes in gene expression. After the cells were exposed to either modulation for 24 h at a specific absorption rate (SAR) of 5 W/ kg, RNA was extracted from both exposed and sham-exposed cells for gene expression analysis. As a positive control, cells were exposed to 0.68 Gy of X rays and gene expression was evaluated 4 h after exposure. Gene expression was evaluated using the Affymetrix U74Av2 GeneChip to detect changes in mRNA levels. Each exposure condition was repeated three times. The GeneChip data were analyzed using a two-tailed t test, and the expected number of false positives was estimated from t tests on 20 permutations of the six sham RF-field-exposed samples. For the X-ray-treated samples, there were more than 90 probe sets with expression changes greater than 1.3-fold beyond the number of expected false positives. Approximately one-third of these genes had previously been reported in the literature as being responsive to radiation. In contrast, for both CDMA and FDMA radiation, the number of probe sets with an expression change greater than 1.3-fold was less than or equal to the expected number of false positives. Thus the 24-h exposures to FDMA or CDMA RF radiation at 5 W/kg had no statistically significant effect on gene expression.
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Affiliation(s)
- T D Whitehead
- Department of Radiation Oncology, Washington University School of Medicine, St. Louis, Missouri 63108, USA
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Chauhan V, Mariampillai A, Bellier PV, Qutob SS, Gajda GB, Lemay E, Thansandote A, McNamee JP. Gene expression analysis of a human lymphoblastoma cell line exposed in vitro to an intermittent 1.9 GHz pulse-modulated radiofrequency field. Radiat Res 2006; 165:424-9. [PMID: 16579654 DOI: 10.1667/rr3531.1] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
This study was designed to determine whether radiofrequency (RF) fields of the type used for wireless communications could elicit a cellular stress response. As general indicators of a cellular stress response, we monitored changes in proto-oncogene and heat-shock protein expression. Exponentially growing human lymphoblastoma cells (TK6) were exposed to 1.9 GHz pulse-modulated RF fields at average specific absorption rates (SARs) of 1 and 10 W/kg. Perturbations in the expression levels of the proto-oncogenes FOS, JUN and MYC after exposure to sham and RF fields were assessed by real-time RT-PCR. In addition, the transcript levels of the cellular stress proteins HSP27 and inducible HSP70 were also monitored. We demonstrated that transcript levels of these genes in RF-field-exposed cells showed no significant difference in relation to the sham treatment group. However, concurrent positive (heat-shock) control samples displayed a significant elevation in the expression of HSP27, HSP70, FOS and JUN. Conversely, the levels of MYC mRNA were found to decline in the positive (heat-shock) control. In conclusion, our study found no evidence that the 1.9 GHz RF-field exposure caused a general stress response in TK6 cells under our experimental conditions.
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Affiliation(s)
- V Chauhan
- Consumer and Clinical Radiation Protection Bureau, Healthy Environment and Consumer Safety Branch, Health Canada, Ottawa, Ontario, Canada K1A 1C1
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