STRESS PROTEINS ARE NOT INDUCED IN MAMMALIAN-CELLS EXPOSED TO RADIOFREQUENCY OR MICROWAVE-RADIATION

The induction of stress proteins in HeLa and CHO cells was investigate d following a 2 h exposure to radiofrequency (RF) or microwave radiati on. Cells were exposed or sham exposed in vitro under isothermal (37 /- 0.2 degrees C) conditions. HeLa cells were exposed to 27- or 2450 M Hz 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 H eLa or CHO cells to 40 degrees C or to 45 mu M cadmium sulfate. Stress protein induction was assayed 24 h after treatment by electrophoresis of whole-cell extracted protein labeled with [S-35]-methionine. Both cell types exhibited well-characterized responses to the positive cont rol stresses. Under these exposure conditions, neither microwave nor R F radiation had a detectable effect on stress protein induction as det ermined by either comparison of RF-exposed cells with sham-exposed cel ls or comparison with heat-stressed or Cd++ positive control cells. (C ) 1997 Wiley-Liss, Inc.