Gene Expression Analysis in Human Peripheral Blood Cells after 900 MHz RF-EMF Short-Term Exposure

Abstract

Radiofrequency electromagnetic fields (RF-EMF) are a basic requirement of modern wireless communication technology. Statutory thresholds of RF-EMF are established to limit relevant additional heat supply in human tissue. Nevertheless, to date, questions concerning nonthermal biological effects have yet to be fully addressed. New versions of microarrays (8 × 60K v2) provide a higher resolution of whole genome gene expression to display adaptive processes in cells after irradiation. In this ex vivo/ in vitro study, we irradiated peripheral blood cells from five donors with a continuous wave of 900 MHz RF-EMF for 0, 30, 60 and 90 min. Gene expression changes ( P ≤ 0.05 and ≥twofold differences above or below the room temperature control exposed samples) were evaluated with microarray analysis. The results were compared with data from room temperature + 2°C samples. Verification of microarray results was performed using bioinformatic analyses and qRT-PCR. We registered a lack of an EMF-specific gene expression response after applying the false discovery rate adjustment (FDR), using a high-stringency approach. Low-stringency analysis revealed 483 statistically significant deregulated transcripts in all RF-EMF groups relative to the room temperature exposed samples without an association with their corresponding room temperature + 2°C controls. Nevertheless, these transcripts must be regarded as statistical artefacts due to the absence of a targeted biological response, including enrichment and network analyses administered to microarray expressed gene subset profiles. Correspondingly, 14 most promising candidate transcripts examined by qRT-PCR displayed an absence of correlation with respect to the microarray results. In conclusion, these findings indicate that 900 MHz EMF exposure establishing an average specific absorption rate of 9.3 W/kg to whole blood cells is insufficient to induce nonthermal effects in gene expression during short-time exposure up to 90 min.

Human Fibroblasts In Vitro Exposed to 2.45 GHz Continuous and Pulsed Wave Signals: Evaluation of Biological Effects with a Multimethodological Approach

“…Since the application of FDR analysis may have determined the exclusion of some true positive events (type 2 error), a second statistical analysis was performed without FDR-corrected approach [ 61 , 77 ], by which only those genes with p -values less than 0.05 and a fold-change of 1.5 were selected. Using this method, as expected, some genes showed differential expression profiles for both types of exposures and for each time point evaluated.…”

NextGEM: Next-Generation Integrated Sensing and Analytical System for Monitoring and Assessing Radiofrequency Electromagnetic Field Exposure and Health

“…In the current published literature, in most cases, no effect was detected, and when present, it was due to a temperature increase. However, some studies suggested that non-thermal exposure can affect a variety of biological functions, including the expression of several genes [ 15 ], although these findings have not been confirmed in other independent investigations [ 17 ]. Overall, results are often contradictory, and well-performed mechanistic studies, using an intervention in biological processes investigating specific biochemical and molecular events and molecules, are needed [ 18 ].…”

Electromagnetic Fields, Genomic Instability and Cancer: A Systems Biological View

“…Several research groups have investigated transcriptomic, proteomic, or metabolomic changes following exposure to ELF or RF electromagnetic fields. Earlier studies have been reviewed [63,64], and additional studies have been published recently [65,66,67,68,69,70,71,72]. There are many limitations in individual studies such as short exposure times, limited range of exposure levels, and limited number of sampling times after exposure.…”