Repetitive exposure to a 60-Hz time-varying magnetic field induces DNA double-strand breaks and apoptosis in human cells.
We investigated the effects of extremely low frequency time-varying magnetic fields (MFs) on human normal and cancer cells. Whereas a single exposure to a 60-Hz time-varying MF of 6mT for 30min showed no effect, repetitive exposure decreased cell viability. This decrease was accompanied by phosphorylation of γ-H2AX, a common DNA double-strand break (DSB) marker, and checkpoint kinase 2 (Chk2), which is critical to the DNA damage checkpoint pathway. In addition, repetitive exposure to a time-varying MF of 6mT for 30min every 24h for 3days led to p38 activation and induction of apoptosis in cancer and normal cells. Therefore, these results demonstrate that repetitive exposure to MF with extremely low frequency can induce DNA DSBs and apoptosis through p38 activation. These results also suggest the need for further evaluation of the effects of repetitive exposure to environmental time-varying MFs on human health.
Kim
Jiyeon
J
Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749, Republic of Korea.
Ha
Chang Seung
CS
Lee
Hae June
HJ
Song
Kiwon
K
D017209:Apoptosis; D002460:Cell Line; D045744:Cell Line, Tumor; D064447:Checkpoint Kinase 2; D053903:DNA Breaks, Double-Stranded; D004574:Electromagnetic Fields; D006657:Histones / Q000378:metabolism; D006801:Humans; D010766:Phosphorylation / Q000528:radiation effects; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
C468783:H2AX protein, human; D006657:Histones; D064447:Checkpoint Kinase 2; C578634:CHEK2 protein, human; D017346:Protein Serine-Threonine Kinases; D048051:p38 Mitogen-Activated Protein Kinases