The effect of repetitive magnetic stimulation on the tumor development

We investigated the effect of the magnetic stimulation on tumor developing processes in vitro and in vivo. B16-BL6 melanoma cells were exposed to repetitive pulsed magnetic stimulation of 0.75 T, 25 pulses/s at the stimulus conditions of 1000, 2000, 3000, and 1000 pulses/day for three days, 3000 pulses in total. 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl-tetrazorium bromide assay was performed to evaluate the cell viability. No significant differences were observed in cell viability between the control and stimulated groups. In animal experiment, B16-BL6 cells were subcutaneously injected into flanks of C57BL/6J mice. From the next day of the injection, repetitive pulsed magnetic stimulation (0.75 T, 25 pulses/s, 1000 pulses/day) was applied to the mice for series of 16 days. The estimated eddy currents induced in tumor area were 2.31-4.61 A/m(2). On day 17, mice were sacrificed and tumor weights were measured. There was no significant difference in the tumor weight between the stimulated group and the sham group. These results suggest that magnetically induced eddy currents have no effect on cancer cells and proliferation in vitro and in vivo.