Ataxia telangiectasia mutated deficiency does not result in genetic susceptibility to 50 Hz magnetic fields exposure in mouse embryonic fibroblasts.

Extremely low frequency magnetic field (ELF-MF) has been classified as a possible carcinogen to humans by the International Agency for Research on Cancer [2002]. However, debate on the genotoxic effects of ELF-MF has continued due to lack of sufficient experimental evidence. Ataxia telangiectasia mutated (ATM) plays a central role in DNA damage repair; its deficiency can result in cellular sensitivity to DNA-damaging agents. To evaluate the genotoxicity of ELF-MF, we investigated the effects of 50 Hz MF on DNA damage in ATM-proficient (Atm+/+ ) mouse embryonic fibroblasts (MEFs) and ATM-deficient (Atm-/- ) MEFs, a radiosensitive cell line. Results showed no significant difference in average number of γH2AX foci per cell (9.37 ± 0.44 vs. 9.08 ± 0.28, P = 0.58) or percentage of γH2AX foci positive cells (49.22 ± 1.86% vs. 49.74 ± 1.44%, P = 0.83) between sham and exposure groups when Atm+/+ MEFs were exposed to 50 Hz MF at 2.0 mT for 15 min. Extending exposure duration to 1 or 24 h did not significantly change γH2AX foci formation in Atm+/+ MEFs. Similarly, the exposure did not significantly affect γH2AX foci formation in Atm-/- MEFs. Furthermore, 50 Hz MF exposure also did not significantly influence DNA fragmentation, cell viability, or cell cycle progression in either cell types. In conclusion, exposure to 50 Hz MF did not induce significant DNA damage in either Atm+/+ or Atm-/- MEFs under the reported experimental conditions. Bioelectromagnetics. 39:476-484, 2018.