Cell viability and growth in a battery of human breast cancer cell lines exposed to 60 Hz magnetic fields

Epidemiological data suggest that exposure to power-frequency (50/60 Hz) ma gnetic fields (MFs) may be a risk factor for breast cancer in humans. To de termine whether MFs affect human breast canter cells, we measured viability , growth and cytotoxicity in a battery of breast cancer cell lines after in vitro MF and sham exposure. Cells of three estrogen receptor-positive huma n breast cancer cell lines (MCF-7, ZR-75-1 and T-47D) and one estrogen rece ptor-negative human breast cancer cell line (MDA-MB-231) and normal (nontra nsformed) human breast epithelial cells were exposed to MFs (1 mT) or sham fields (<0.0001 mT) for 72 h. Cell viability was determined using the sulfo rhodamine B (SRB) assay at 0 and 72 h after the MF exposure period. Cell gr owth was measured as the change in SRB dye uptake over 72 h after MF exposu re. MF exposure had no effect on cell viability or growth in any cell type examined. Similarly, MF exposure had no effect on cytotoxicity induced by e xposure to the retinoid N-(4-hydroxyphenyl)retinamide. These data do not su pport the hypothesis that MF exposure stimulates growth of breast cancer ce lls. (C) 2000 by Radiation Research Society.