60 Hz magnetic fields do not enhance cell killing by genotoxic chemicals in ataxia telangiectasia and normal lymphoblastoid cells

Ataxia telangiectasia (AT) is an inherited autosomal recessive disease char acterized by increased risk of cancer, immune deficiency, and neurodegenera tion, Cells cultured from AT patients are highly sensitive to genotoxic age nts and are deficient in cell cycle arrest after exposure to ionizing radia tion. In consideration of their sensitivity to both ionizing and nonionizin g radiation, AT cells may provide a sensitive model system to study the bio logical activity of other components of the electromagnetic spectrum. To ch aracterize the effects of power-frequency (60 Hz) magnetic fields (MFs) in AT cells, we compared responses of AT and normal lymphoblast cells to sinus oidal MFs at 1.0 mT, either alone or in combination with the genotoxic agen ts mitomycin C or streptonigrin, The MF alone had no effect on cell growth or survival in a clonogenic assay in either AT or normal cells. The MF also had no effect on induction of cell death by mitomycin C or streptonigrin i n either cell type. AT cells do not demonstrate differential sensitivity to MF exposure. These results do not support the hypothesis that MFs interact with genotoxic agents to induce adverse biological effects in either norma l or genetically susceptible human cells. (C) 2000 by Radiation Research So ciety.