Extremely low frequency electromagnetic field selectively impairs breast cancer cells through apoptosis

Background: Breast cancer (BC) is the most common cancer among women worldwide. The treatment options depending on the stage of cancer include surgery, chemotherapy, or ionizing radiation (IR) or a combination of them. Both chemotherapy and IR can be effective against BC, but they also kill surrounding normal tissues. Therefore, developing selective treatment is necessary. Recent studies have shown that non-ionizing electromagnetic fields (EMFs) in specific frequency ranges and intensities have anticancer therapeutic effects. Extremely low frequency EMFs (ELF-EMFs) in moderate intensities have reportedly shown anticancer effects in different cancer types. Therefore, this study aims to investigate the selectivity of the treatment and the mechanisms of actions ELF-EMF at 50 HZ and 3 mT on breast cancer cells. Objective: To comparatively investigate the effects of 50 Hz ELF-EMF at 3mT at two exposure times of 24 and 48 hrs on breast normal (MCF-10) and cancer cells (MCF-7) and also to assess the selectivity and mechanism of action of the EMFs on BC cells. Method: The cells were cultured in DMEM medium and treated by EMF (50 HZ, 3 mT) for 24 and 48 hrs in a special purpose EMF generator device with uniform exposure. The cell viability and apoptosis percentage in the treated cells were assessed using MTT assay and flow cytometry, apoptosis assay by Annexin V staining, respectively. Results: The 50 Hz ELF-EMF in 3mT induced more mortality rates in MCF-7 than MCF-10 which were significant for both 24 (78.1% versus 98.7%) (P=0.013) and 48 (41.6% versus 92.39%) h (P=0.0001) exposure. times. Interestingly, increasing exposure time from 24 to 48 h did not significantly increase the mortality rate in normal breast cell line (P=0.9), whereas significantly increased the mortality rate in cancerous cell line by 60%. In the 48 h exposure time, apoptosis percentage significantly increased in cancerous cells, compared to the control cells (by 8.8%) (P=0.001). Conclusion: Our data suggest that 50 HZ ELF-EMF at 3 mT selectively impaired breast cancer cell viability while did not affect normal cell line. The main mechanism of action of the cell death in cancerous breast cell line is induction of apoptosis. These data suggest that 50 Hz ELF-EMF may be a potential BC treatment.