Stress proteins are not induced in mammalian cells exposed to radiofrequency or microwave radiation

Abstract

The induction of stress proteins in HeLa and CHO cells was investigated following a 2 h exposure to radiofrequency (RF) or microwave radiation. Cells were exposed or sham exposed in vitro under isothermal (37 ± 0.2 °C) conditions. HeLa cells were exposed to 27‐ or 2450 MHz continuous wave (CW) radiation at a specific absorption rate (SAR) of 25 W/kg. CHO cells were exposed to CW 27 MHz radiation at a SAR of 100 W/kg. Parallel positive control studies included 2 h exposure of HeLa or CHO cells to 40 °C or to 45 μM cadmium sulfate. Stress protein induction was assayed 24 h after treatment by electrophoresis of whole‐cell extracted protein labeled with [³⁵S]‐methionine. Both cell types exhibited well‐characterized responses to the positive control stresses. Under these exposure conditions, neither microwave nor RF radiation had a detectable effect on stress protein induction as determined by either comparison of RF‐exposed cells with sham‐exposed cells or comparison with heat‐stressed or Cd⁺⁺ positive control cells. Bioelectromagnetics 18:499–505, 1997.