Authors: Djuari, M. A. ; Engelke, M.;Reamon-Buettner, S. M.; Ziemann, C.; Bitsch, A.
53rd EEMGS, Bratislava, Slovakia, 02-05 June 2025.
Abstract
A more stable, faster mobile communications is nowadays increasingly important. The latest innovation is the fifth generation of mobile telephony (5G New Radio). A major advancement in 5G technology is the introduction of a second frequency range (FR2) between 24.52 GHz and 52.6 GHz in the millimeter wave (mmWave) spectrum, which exhibits low-penetration depth. Thus, skin represents the main target organ for potential adverse FR2 effects. Therefore, the EU-funded SEAWave project aims, among others, to investigate biological effects of FR2 on human and rodent skin.
Here, we investigated potential mmWave-mediated induction of DNA-strand breaks and oxidative DNA-lesions as well as transcriptomic changes in low-pigmented primary human juvenile epidermal keratinocytes (NHEK) using the hOOG1-modified alkaline comet assay and microarray technology, respectively. After characterization of cells (growth behavior, chromosome number), cells were exposed blinded to mmWave at three power densities, i.e., sham, 3.33, or 10 W/m2 for 24 h, with subsequent analysis of DNA integrity and gene expression. Cytotoxicity was determined in parallel by automatic cell counting.
After 24 h of exposure to mmWave, no cytotoxicity and direct DNA damage, i.e., increase in median- based mean tail intensity (maximum fold change of 1.09), was noted. When comparing results ± hOOG1 treatment, no oxidative DNA damage was present in NHEK cells. Transcriptome analysis showed that after 24 h of exposure at 3.33 W/m2, some pathways were shown activated, including mitochondrial dysfunction and sonic hedgehog signaling pathway, and some pathways were inhibited, such as triacylglycerol biosynthesis at 3.33 W/m2 and renin-angiotensin signaling at 10 W/m2.
In conclusion, after 24 h of exposure, mmWave did not induce DNA damage or oxidative DNA lesions in NHEK cells, but nevertheless activated and inhibited certain pathways, some of which are
important for cell growth. Further analyses will investigate DNA damages, gene expression, epigenetic landscape and telomere length in additional skin cell models.