Cells were divided into four groups: 1) control group, 2) ionizing radiation (60Co, 5 Gy) group, 3) microwave exposure group, and 4) "microwave + ionizing radiation" exposure group. Group 3 and 4 were further divided into different subgroups according to the intensity of microwave exposure.
|Exposure duration||continuous for 2 h/day on 3 days|
Exposure of glioma cells to 900 MHz (group 3; 4 mW/cm² and 6 mW/cm² ) microwaves and exposure to 6 mW/cm² in combination with gamma radiation resulted in a significant inhibition of cell proliferation. Furthermore, pre-exposure with 900 MHz microwaves followed by gamma radiation significantly increased the rate of apoptosis in a dose-dependent manner.
Both, 900 MHz microwave exposure and gamma radiation did not produce significant effects on cell cycle phase distribution.
The co-exposure of electromagnetic fields and gamma radiation resulted in a synergistic effect by triggering stress response, which increased reactive oxygen species (increase of MDA, decrease of superoxide dismutase in group 4 (with 6 mW/cm²)), but the expression of HSP70 remained unchanged.
The data indicate that the adverse effects of gamma radiation on cellular functions are strengthened by electromagnetic fields.