ID Number		1663
Study Type		In Vitro
Model		864, 915 and 1800 MHz exposure to V79 hamster cells and neuroblastoma cells and analysis of growth, viability, microtubular structure and oxidation-reduction processes.
Details		V79 Chinese hamster cells were exposed to 864 and 935 MHz (CW) at an average SAR of 0.08 or 0.12 W/kg, respectively, for 2-3 hours in a TEM cell and analyzed for growth and viability. The authors report exposure decreased growth on the 3rd day following exposure, although colony forming ability and viability remained unaffected. In a subsequent study, V79 cells were again exposed to 935 MHz (CW) for 3 hours and evaluated for growth at 24, 48, 72, 96, and 120 hours. The authors again report decreased growth on the 3rd day following exposure with some evidence of blocked microtubule formation as a mechanism. In a study reported in 2009, the authors report exposure as above (V79 exposed to 935 MHz at 0.12 W/kg for 1, 2, or 3 hr and analyzed at 24, 48, 72, and 96 hrs post exposure). The authors again report that cells analyzed for growth on the 3rd day following exposure showed statistically significant reductions in growth. There were also irregularities in cell morphology and microtubule structure, but not in mitotic index. AUTHORS' ABSTRACT: Marjanovic, Pavicic and Trosic 2014 (IEEE #5691): Aim of this study was to evaluate an influence of modulated radiofrequency field (RF) of 1800 MHz, strength of 30 V/m on oxidation-reduction processes within the cell. The assigned RF field was generated within Gigahertz Transversal Electromagnetic Mode cell equipped by signal generator, modulator, and amplifier. Cell line V79, was irradiated for 10, 30, and 60 min, specific absorption rate was calculated to be 1.6 W/kg. Cell metabolic activity and viability was determined by MTT assay. In order to define total protein content, colorimetric method was used. Concentration of oxidised proteins was evaluated by enzyme-linked immunosorbent assay. Reactive oxygen species (ROS) marked with fluorescent probe 2',7'-dichlorofluorescin diacetate were measured by means of plate reader device. In comparison with control cell samples, metabolic activity and total protein content in exposed cells did not differ significantly. Concentrations of carbonyl derivates, a product of protein oxidation, insignificantly but continuously increase with duration of exposure. In exposed samples, ROS level significantly (p < 0.05) increased after 10 min of exposure. Decrease in ROS level was observed after 30-min treatment indicating antioxidant defence mechanism activation. In conclusion, under the given laboratory conditions, modulated RF radiation might cause impairment in cell oxidation-reduction equilibrium within the growing cells. AUTHORS' ABSTRACT: Marjanovic, Pavicic and Trosic 2012 (IEEE #5949): Over the years, due to rapid technological progress, radiation from man-made sources exceeded that of natural origin. There is a general concern regarding a growing number of appliances that use radiofrequency/ microwave (RF/MW) radiation with particular emphasis on mobile communication systems. Since nonthermal biological effects and mechanisms of RF/MW radiation are still uncertain, laboratory studies on animal models, tissues, cells, and cell free system are of extraordinary importance in bioelectromagnetic research. We believe that such investigations play a supporting role in public risk assessment. Cellular systems with the potential for a clear response to RF/MW exposures should be used in those studies. It is known that organism is a complex electrochemical system where processes of oxidation and reduction regularly occur. One of the plausible mechanisms is connected with generation of reactive oxygen species (ROS). Depending on concentration, ROS can have both beneficial and deleterious effects. Positive effects are connected with cell signalling, defence against infectious agents, and proliferative cell ability. On the other hand, excessive production, which overloads antioxidant defence mechanism, leads to cellular damage with serious potential for disease development. ROS concentration increase within the cell caused by RF/MW radiation seems to be a biologically relevant hypothesis to give clear insight into the RF/MW action at non-thermal level of radiation. In order to better understand the exact mechanism of action and its consequences, further research is needed in the field. We would like to present current knowledge on possible biological mechanisms of RF/MW actions. AUTHORS' ABSTRACT: Trosic et al. 2012 (IEEE #6284): This article gives a review or several hypotheses on the biological effects of non-thermal radiofrequency/microwave (RF/MW) radiation and discusses our own findings from animal and in vitro studies performed over the last decade. We have found that RF/MW radiation disturbs cell proliferation and leads to cell differentiation in the bone marrow, which is reflected in the peripheral blood of rats. Repeated RF/MW radiation can also temporarily disrupt melatonin turnover. The observed changes seem to be a sign of adaptation to stress caused by irradiation rather than of malfunction. The article looks further into the basic mechanisms of RF/MW biological action, including cell growth parameters, colony-forming ability, viability, and the polar and apolar protein cytoskeleton structures. The observed reversible cell changes significantly obstructed cell growth. In contrast to the apolar intermediate proteins, the intracellular polar microtubule and actin fibres were damaged by radiation in a time-dependent manner. These significantly altered parameters can be considered as the biomarkers of exposure. Future research should combine dosimetry, experimental studies, and epidemiological data. AUTHORS' ABSTRACT: Marjanovic Cermak et al. 2017 (IEEE # 6875): The exact mechanism that could explain the effects of radiofrequency (RF) radiation exposure at non-thermal level is still unknown. Increasing evidence suggests a possible involvement of reactive oxygen species (ROS) and development of oxidative stress. To test the proposed hypothesis, human neuroblastoma cells (SH-SY5Y) were exposed to 1800 MHz short-term RF exposure for 10, 30 and 60 minutes. Electric field strength within Gigahertz Transverse Electromagnetic cell (GTEM) was 30 V m-1 and specific absorption rate (SAR) was calculated to be 1.6 W kg-1. Cellular viability was measured by MTT assay and level of ROS was determined by fluorescent probe 2',7'-dichlorofluorescin diacetate. Concentrations of malondialdehyde and protein carbonyls were used to assess lipid and protein oxidative damage and antioxidant activity was evaluated by measuring concentrations of total glutathione (GSH). After radiation exposure, viability of irradiated cells remained within normal physiological values. Significantly higher ROS level was observed for every radiation exposure time. After 60 min of exposure, the applied radiation caused significant lipid and protein damage. The highest GSH concentration was detected after 10 minute-exposure. The results of our study showed enhanced susceptibility of SH-SY5Y cells for development of oxidative stress even after short-term RF exposure.
Findings		Effects
Status		Completed With Publication
Principal Investigator		Inst Med Research, Zagreb, Croatia - ipavicic@imi.hr
Funding Agency		Croatian Ministry Sci Ed Sport
Country		CROATIA (local name: Hrvatska)
References		Trosic, I et al. Arh Hig Rada Toksikol., (2009) 60:109-115 Pavicic, I et al. Toxicol In Vitro, (2008) 22:1344-1348 Pavicic, I et al. Arh Hig Rada Toksikol, (2006) 57:149-154 Marjanovic, AM et al. Electromagn Biol Med., (2015) 34:381-386 Marjanovic , AM et al. Arh Hig Rada Toksikol., (2012) 63:407-416 Trosic, I et al. Arh Hig Rada Toksikol., (2012) 63 Suppl 1.:67-73 Marjanovic Cermak, AM et al. Gen Physiol Biophys., (2017) 36:407-414 Marjanovic Cermak, AM et al. J Environ Sci Health A Tox Hazard Subst Environ Eng., (2018) 53:132-138 Cermak, AMM et al. Arh Hig Rada Toksikol., (2020) 71:205-210
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