Pulsed electromagnetic field at frequency and intensity resembling potassium ion cyclotron resonance selectively impairs breast cancer cell through apoptosis

Introduction: Breast cancer (BC) is the most common women cancer worldwide. Radiotherapy and chemotherapy are the two common treatment options but these techniques suffer low selectivity and adverse effects on surrounding normal tissues. Non- ionizing pulsed electromagnetic fields (PEMFs) in ultra-narrow band frequency and intensity have shown anticancer effects. Changing potassium ion (K+) activities is a pivotal mechanism regulating different physiological functions and cell proliferation. PEMFs at ion cyclotron resonance (ICR) frequency tuned to main biological ions such as K+ can modulate cell cycle and proliferation. The present study aims to comparatively investigate the effects of PEMF at frequency and intensity resembling K+-ICR condition (50 Hz, 127.2 µT) on cancerous (MCF-7) and normal breast (MCF-10) cells. In addition, the mechanisms of actions of the PEMF were assessed using MTT and flow cytometry assessments. Materials and Methods: The both cell lines had been treated by PEMF (50 HZ, 127.2 µT) for 24 and 48 h in a special purpose built PEMF generator that generated uniform magnetic fields resembling the K+-ICR condition at 50 Hz and intensity of 127.2 µT. The cell viability and apoptosis percentage were respectively assessed using MTT assay and flow cytometry with Annexin V apoptosis protocol. Results: In the PEMF (50 HZ and 127.2 µT) with 24 h exposure time, viability percentage of cancer cells significantly decreased compared to the normal cells (74.79% versus 90%) (P=0.007). Increasing the exposure time from 24 h to 48 h did not significantly alter the MCF- 10 cells proliferation (90% to 91.5%)(P=0.97). Contrary, the mortality rate in MCF-7 cell line significantly increased by 23.49% (P=0.0006). In the 48 h exposure time, late and early apoptosis percentage significantly increased in MCF-7 cells, compared to the control cells (9.96 ± 0.024 Versus 4.03 ± 0.025) (P= 0.001) Conclusion: PEMF with K+-ICR condition selectively impairs breast cancer cell viability while did not affect normal cell line. Induction of apoptosis seems the main mechanism of actions of cell death in the cancerous breast cell line under PEMF exposure. These data suggest that PEMF tuned to K+-ICR may be a potential BC treatment.