Proteomic Analysis of the Response

Background: We have earlier shown that exposure of human endothelial cell line EA.hy926 to 900 MHz GSM mobile phone radiation causes changes in the expression of numerous proteins. Here, we have examined the effects of 1800 MHz GSM mobile phone signal on the proteome of the same cell line. Results: EA.hy926 cells were exposed for one hour to 1800 MHz GSM signal, simulating mobile phone talking conditions, at an average specific absorption rate (SAR) of 2.0 W/kg at 37±0.3°C. Sham samples were produced simultaneously in the same conditions but without the radiation exposure. Cells were harvested immediately after 1-hour exposure to the radiation, and proteins were extracted and separated using 2-dimensional electrophoresis (2DE). In total, 10 experimental replicates were generated from both exposed and sham samples. About 900 protein spots were detected in the 2DE-gels using PDQuest software and eight of them were found to be differentially expressed in exposed cells (p<0.05, t-test). Three out of these eight proteins were identified using Maldi-ToF mass spectrometry (MS). These proteins are: spermidine synthase (SRM), 78 kDa glucose-regulated protein (55 kDa fragment) (GRP78) and proteasome subunit alpha type 1 (PSA1). Due to the lack of the availability of commercial antibodies we were able to further examine expression of only GRP78. Using SDSPAGE and western blot method we were not able to confirm the result obtained for GRP78 using 2DE. Additionally, we have not seen any effect of 1800GSM exposure on the expression of vimentin and Hsp27 proteins that were affected by the 900 MHz GSM exposure in our earlier studies. Conclusions: Our results suggest that the 900GSM and 1800GSM exposures might affect the expression of some proteins in the EA.hy926 cell line. The observed here discrepancy between the expression changes of GRP78 detected with 1DE and 2DE confirms the importance of validation of the results obtained with 2DE using other methods, e.g. western blot. *Corresponding author: Dariusz Leszczynski, PhD, STUK-Radiation and Nuclear Safety Authority, Laippatie 4, 00880 Helsinki, Finland, E-mail: [email protected] Received September 22, 2009; Accepted October 26, 2009; Published October 26, 2009 Citation: Nylund R, Tammio H, Kuster N, Leszczynski D (2009) Proteomic Analysis of the Response of Human Endothelial Cell Line EA.hy926 to 1800 GSM Mobile Phone Radiation. J Proteomics Bioinform 2: 455-462. doi:10.4172/jpb.1000105 Copyright: © 2009 Nylund R, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Proteomic Analysis of the Response of Human Endothelial Cell Line EA.hy926 to 1800 GSM Mobile Phone Radiation Reetta Nylund, Hanna Tammio, Niels Kuster, Dariusz Leszczynski* STUK Radiation and Nuclear Safety Authority, Helsinki, Finland IT’IS Foundation, Swiss Federal Institute of Technology, Zurich, Switzerland Abbreviations: 2DE: Two-dimensional electrophoresis; CHAPS: 3-[(3Cholamidopropyl)dimethylammonio]-1propanesulfonate; Da: Dalton; ddH 2 O: Double distilled water; DMEM: Dulbecco’s Modified Eagle’s Medium; DTT: Dithioreitol; EA.hy926: Human endothelial cell line; ECL Enhanced chemiluminescence; GSM: Global System for Mobile Communications; HAT: (mixture of) sodium hypoxanthine, aminopterin, and thymidine; HRP: Horseradish peroxidase; IAA: Iodoacetamide; IEF: Isoelectric focusing; IPG: Immobilized pH gradient; LR: Linear-reflectron; MALDI-TOF: Matrix-assisted laser desorption/ionization time of flight; MS: Mass spectrometry/ mass spectrometer; NH 4 HCO 3 : Ammoniumbicarbonate; PAGE: Polyacrylamide gel electrophoresis; PBS: Phosphate buffered saline; pI: Isoelectric point; PMF: Peptide mass fingerprint; PMSF: Phenylmethylsulphonyl fluoride; PVDF: Polyvinylidene Fluoride; RF-EMF: Radiofrequency modulated electromagnetic field; SAR: Specific absorption rate; SDS: Sodium dodecyl sulphate; Tris-HCl: Tris(hydroxymethyl)aminomethane hydrochloride; Versene: Chelating agent containing EDTA