Exposure of Daudi cells to low-frequency magnetic fields does not elevate MYC steady-state mRNA levels.

Abstract

The effect of extremely low-frequency electromagnetic field (ELF EMF) exposures to human health has been widely debated. Epidemiological studies have found a possible correlation between increased cancer incidence and environmental ELF EMF exposures. Results from in vitro studies performed to examine the possible underlying bioeffects of ELF EMFs have varied greatly. Reported effects range from robust and reproducible effects to undetectable. In this study, Daudi cells were exposed to 60 Hz magnetic fields for 20, 40 or 60 min at flux densities of 12.5, 50, 100 or 500 microT. Exposures were performed in the Regional ELF-EMF Exposure Facility (Rockville, MD) to minimize variables that might contribute to a false positive effect. Exposures included sham/sham, exposed/sham or sham/exposed, and were performed with blinding with respect to type of exposure. 12-O-Tetradecanoylphorbol-13-acetate (TPA) treatment was used as a positive control. Total cellular RNA was isolated using a single-step technique. Human MYC expression was measured by northern blot hybridization as an indicator of the responsiveness of Daudi cells to experimental conditions. Beta-2-microglobulin (B2M) expression was measured simultaneously as an internal control. Exposure to a 60 Hz magnetic field did not significantly alter MYC expression in Daudi cells under any of the exposure conditions.