On the basis of our recent in vitro evidence for the carcinogenic action of 2.45 GHz microwaves (MW), we propose to assess the effect of MW, in the absence of MW heating (less than 0.3 degrees C temperature rise during MW cell exposure), on in vitro oncogenic transformation with or without other co-stressors [X rays, tumor promoter 12-0-tetradecanoyl-phorbol-13-acetate (TPA)]. Our experiments aim at: (a) the elucidation of interaction mechanisms at the cellular level leading to oncogenic effects, (b) the establishment of the MW dose-response relationship in terms of the specific absorption rate (SAR) for oncogenic effects. We will use the C3H/10T1/2 cell line derived from mouse embryo cells in which transformation is quantitated by scoring piled-up foci on top of a confluent monolayer. Experiments will be performed at 37 degrees C with actively growing cultures. The effect of MW on C3H/10T1/2 cells in culture will be measured by comparing the number of transformants induced by free-field microwave irradiation lasting for 24 h (SAR = 0.1 to 10 W/kg) with or without subsequent post-treatment culture in TPA at 0.1 g/ml for up to 8 weeks. Parallel experiments will include the use of graded doses of X rays as a second initiator of transformation in conjunction with microwaves and tumor promoter to test hypothesis that the prolonged exposure to microwaves can enhance and elicit effect of other carcinogens. The importance of understanding of the cellular mechanisms whereby non-thermal MW fields interact with biological systems is important due to the pervasive presence of such fields in the environment.
