Exposure to 60 Hz magnetic field can affect membrane proteins and membrane potential in human cancer cells

The experimental data support the hypothesis that extremely low frequency magnetic field (ELF-MF) can affect cell membranes. Since our previous studies suggested that MF changes the permeability of cell membrane, in this study we focused on the cell membrane and investigated the effect of 60 Hz, 50 mT MF on the membrane potential and membrane proteins. The membrane potentials of three cultured human cancer cell lines, A549, MES-SA, and MES-SA/Dx5, were increased by exposure to ELF-MF. When exposed to MF and an anticancer drug, changes in the membrane potentials were detected in A549 and MES-SA cells, but not in the multi drug-resistant cells, MES-SA/Dx5. We examined whether MF has an influence on the membrane proteins extracted from cultured A549 cells, using DiBAC₄(3) dye enhanced fluorescence binding to a hydrophobic site. The increase in fluorescence observed following MF exposure for 10 min indicated that the structure of the hydrophobic site on the membrane proteins changed and became more likely to bind the probe dye. A decrease in fluorescence was detected following exposure to MF for 240 min. These results indicated that 60 Hz, 50 mT MF causes changes in the membrane potential of cultured cancer cells and the conformation of membrane proteins extracted from cultured cancer cells, and has different effects depending on the exposure time.

Magnetic fields enhance the anti-tumor efficacy of low dose cisplatin and reduce the nephrotoxicity

The present work was to examine a combination of therapy for a low dose of cisplatin and a magnetic field (MF) on Ehrlich carcinoma-bearing mice. In this study, a total of 50 BALB/C female mice were equally distributed into five groups. Mice from the control group did not receive MF or cisplatin. The low and high dose cisplatin groups were injected intraperitoneal (i.p.) with 3 and 6 mg/kg cisplatin, respectively, on the experimental days (1, 4, and 8). Mice group of cisplatin + MF was injected with a low dose of cisplatin followed by MF exposure (50 Hz, 50 mT), and the MF group was exposed to MF only. The impact of MF and cisplatin on the tumor and kidney were evaluated by measuring superoxide dismutase (SOD) activity, malondialdehyde (MDA) and glutathione (GSH) levels, DNA injury (comet assay), histopathological investigation of tissues, and tumor progress. The results suggested that the combination of a low dose of cisplatin with MF was significantly elevated in MDA levels, reduced SOD activity, and GSH levels. Furthermore, it caused a rise in comet parameters and inhibition in tumor growth. These results showed that MF enhances the therapeutic efficacy of low cisplatin doses and reduces nephrotoxicity.