Recent investigations into the biological effects of radiofrequency radiation (RFR) have revealed a potential epigenetic dimension to cellular response. A pivotal study by the U.S. Air Force Research Laboratory, as detailed in the IEEE Xplore document with DOI: 10.1109/ACCESS.2022.3174249, demonstrated that low-level RF exposure can elicit immediate changes in DNA methylation patterns within human keratinocytes. Utilizing whole-genome bisulfite sequencing, the research identified alterations in gene expression regulation, suggesting a profound epigenetic role in the cellular response to RFR. These findings challenge the longstanding paradigm that RFR’s biological impact is limited to thermal effects, thereby uncovering the potential for epigenetic biomarkers of RF exposure and opening new inquiries into the non-thermal interactions between electromagnetic fields and living systems. This abstract encapsulates the essence of the study and its significance in the expanding field of bioelectromagnetics
Methylation changes refer to alterations in the DNA methylation patterns within the genome, which is a key epigenetic mechanism. DNA methylation typically involves the addition of a methyl group to the DNA molecule, usually at cytosine bases that are followed by guanine bases, known as CpG sites. This process can influence gene expression without altering the underlying DNA sequence.
Research on Methylation Changes Due to RF Exposure:
The research conducted by the U.S. Air Force Research Laboratory investigated the immediate effects of RF exposure on human keratinocytes, which are the predominant cell type in the outer layer of the skin. The study used whole-genome bisulfite sequencing, a technique that can determine the methylation status of CpG sites throughout the genome, to observe changes in DNA methylation patterns following exposure to RF radiation.
Key findings from such research include:
- Changes in DNA Methylation: After exposing human keratinocytes to 900 MHz RF radiation, researchers observed immediate alterations in DNA methylation patterns. This suggests that RF exposure can lead to epigenetic changes.
- Gene Expression: The study found early differentially methylated genes, which implies that RF exposure could potentially affect gene expression. Methylation typically acts to suppress gene expression when it occurs in the promoter regions of genes.
- Potential Biomarkers: The changes in methylation patterns could potentially serve as biomarkers for cellular responses to RF exposure. Biomarkers are indicators of a biological state or condition and are useful in detecting or monitoring disease processes or responses to exposure or intervention.
Effects of Methylation Changes:
- Gene Expression Regulation: Methylation changes can lead to the silencing or activation of genes. When methylation occurs in gene promoter regions, it usually suppresses gene expression. Conversely, demethylation can activate the expression of previously silenced genes.
- Cellular Function and Development: Since gene expression is fundamental to cell function and development, changes in methylation can have wide-ranging effects on cellular processes, including cell differentiation, proliferation, and apoptosis (programmed cell death).
- Health Implications: Abnormal DNA methylation patterns are associated with a variety of health issues, including cancers, neurological disorders, and developmental diseases. For example, hypermethylation of tumor suppressor genes can lead to their inactivation, which might contribute to cancer development.
- Epigenetic Inheritance: Some methylation patterns can be inherited, meaning the effects of RF exposure might not be limited to the individual exposed but could potentially be passed down to offspring, affecting their gene expression patterns as well.
It’s important to note that while these studies provide valuable insights into the potential epigenetic effects of RF exposure, they do not necessarily indicate that these changes will lead to adverse health outcomes. The biological significance of these changes depends on many factors, including the specific genes affected, the duration and level of exposure, and the individual’s overall health and genetic background.
The findings suggest that the biological response to RF radiation is more complex than previously understood and may involve epigenetic mechanisms. This research potentially opens up a new understanding of how RF radiation can interact with biological systems and highlights the need for further studies to fully understand the implications of these interactions for human health.
The increasing use of nonionizing radiofrequency electromagnetic fields (RF-EMFs) in a wide range of technologies necessitates studies to further understand of biological effects from exposures to such forms of electromagnetic fields. While previous studies have described mechanisms for cellular changes occurring following exposure to low-intensity RF-EMFs, the role of molecular epigenetics has not been thoroughly investigated. Specifically unresolved is the effect of RF-EMFs on deoxyribonucleic acid (DNA) methylation, which is a powerful epigenetic process, used by cells to regulate gene expression. DNA methylation is dynamic and can be rapidly triggered in response to external stimuli such as exposure to RF-EMFs. In the present study, we performed a global analysis of DNA methylation patterns in human keratinocytes exposed to 900 MHz RF-EMFs for 1 h at a low dose rate (estimated mean specific absorption rate (SAR) < 10 mW/kg). We used a custom system to allow stable exposure of cell cultures to RF-EMFs under biologically relevant conditions (37 °C, 5% CO2 , 95% humidity). We performed whole genome bisulfite sequencing directly following RF-EMF exposure to examine the immediate changes in DNA methylation patterns and identify early differentially methylated genes in RF-EMF-exposed keratinocytes. By correlating global gene expression to whole genome bisulfite sequencing, we identified six common targets that were both differentially methylated and differentially expressed in response to RF-EMF exposure. The results highlight a potential epigenetic role in the cellular response to RF-EMFs. Particularly, the six identified targets may potentially be developed as epigenetic biomarkers for immediate responses to RF-EMF exposure.
Keywords: DNA methylation; epigenetics; keratinocytes; radiofrequency.