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

摘要

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 50Hz 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 H2AX foci per cell (9.37 +/- 0.44 vs. 9.08 +/- 0.28, P=0.58) or percentage of H2AX 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 50Hz MF at 2.0mT for 15min. Extending exposure duration to 1 or 24h did not significantly change H2AX foci formation in Atm(+/+) MEFs. Similarly, the exposure did not significantly affect H2AX foci formation in Atm(-/-) MEFs. Furthermore, 50Hz MF exposure also did not significantly influence DNA fragmentation, cell viability, or cell cycle progression in either cell types. In conclusion, exposure to 50Hz MF did not induce significant DNA damage in either Atm(+/+) or Atm(-/-) MEFs under the reported experimental conditions. Bioelectromagnetics. 39:476-484, 2018. (c) 2018 Wiley Periodicals, Inc.