Adaptive response in human blood lymphocytes exposed to non-ionizing radiofrequency fields: resistance to ionizing radiation-induced damage

Abstract

The aim of this preliminary investigation was to assess whether human peripheral blood lymphocytes which have been pre-exposed to non-ionizing radiofrequency fields exhibit an adaptive response (AR) by resisting the induction of genetic damage from subsequent exposure to ionizing radiation. Peripheral blood lymphocytes from four healthy donors were stimulated with phytohemagglutinin for 24 h and then exposed for 20 h to 1950 MHz radiofrequency fields (RF, adaptive dose, AD) at an average specific absorption rate of 0.3 W/kg. At 48 h, the cells were subjected to a challenge dose (CD) of 1.0 or 1.5 Gy X-irradiation (XR, challenge dose, CD). After a 72 h total culture period, cells were collected to examine the incidence of micronuclei (MN). There was a significant decrease in the number of MN in lymphocytes exposed to RF + XR (AD + CD) as compared with those subjected to XR alone (CD). These observations thus suggested a RF-induced AR and induction of resistance to subsequent damage from XR. There was variability between the donors in RF-induced AR. The data reported in our earlier investigations also indicated a similar induction of AR in human blood lymphocytes that had been pre-exposed to RF (AD) and subsequently treated with a chemical mutagen, mitomycin C (CD). Since XR and mitomycin-C induce different kinds of lesions in cellular DNA, further studies are required to understand the mechanism(s) involved in the RF-induced adaptive response.

Modifying effects of low-intensity extremely high-frequency electromagnetic radiation on content and composition of fatty acids in thymus of mice exposed to X-rays

“…It was shown that the apoptosis rate of BEL-7402 cells, a human hepatoma cell line, exposed to X-rays (2-8 Gy) could be significantly increased by alternating MF (100 Hz, 0.7 mT) (Jian et al 2009). Pre-exposure of human peripheral blood lymphocytes to 1950-MHz UMTS (Universal Mobile Telecommunications System) radiofrequency (RF) field (for 20 h at 0.3 W/kg specific absorption rate (SAR)) significantly decreased the number of micronuclei after subsequent exposure of the cells to X-rays (1 and 1.5 Gy) as compared with those subjected to X-rays alone (Sannino et al 2014). Using the comet assay technique there were no found any synergistic effects of 1.8-Int J Radiat Biol Downloaded from informahealthcare.com by Korea University on 12/27/14…”

The Protective Effect of Autophagy on DNA Damage in Mouse Spermatocyte-Derived Cells Exposed to 1800 MHz Radiofrequency Electromagnetic Fields

“…Thus, autophagy can play a dual role in determining cell fate by two process, not only can it play a protective role, but autophagy can also lead to cell death [44]. Autophagy can induce an adaptive response to protect against chemical mutagens and ionizing radiation [45][46][47][48]. This protective role is generally described as an adaptive response and has been well documented in human and animal cells [49].…”

Enhancement of X-ray Induced Apoptosis by Mobile Phone-Like Radio-Frequency Electromagnetic Fields in Mouse Spermatocyte-Derived Cells

“…It was found that pre-exposure to an RF field protected cultured cells from the damaging effects of ionizing radiation [27,28]. For example, human blood lymphocytes exposed to 1950MHz RF fields resulted in a resistance to subsequent 1.0 or 1.5 Gy X-irradiation induced DNA damage.…”