Proto-oncogene mRNA levels and activities of multiple transcription factors in C3H 10T1/2 murine embryonic fibroblasts exposed to 835.62 and 847.74 MHz cellular phone communication frequency radiation

This study was designed to determine whether tao differently modulated radi ofrequencies of the type generally used in cellular phone communications co uld elicit a general stress response in a biological system. The two modula tions and frequencies studied were a frequently-modulated continuous wave ( FMCW) with a carrier frequency of 835.62 MHz and a code division multiple-a ccess (CDMA) modulation centered on 847.74 MHz. Changes in proto-oncogene e xpression, determined by measuring For, Jun, and Myc mRNA levels as well as by the DNA-binding activity of the AP1, AP2 and NF-kappa B transcription f actors, were used as indicators of a general stress response, The effect of radiofrequency exposure on proto-oncogene expression was assessed (1) in e xponentially growing C3H 10T 1/2 mouse embryo fibroblasts during their tran sition to plateau phase and (2) during transition of serum-deprived cells t o the proliferation cycle after serum stimulation. Exposure of serum-depriv ed cells to 835.62 MHz FMCW or 847.74 MHz CDMA microwaves (at an average sp ecific absorption rate, SAR, of 0.6 W/kg) did not significantly change the kinetics of proto-oncogene expression after serum stimulation, Similarly, t hese exposures did not affect either the Jun and Myc mRNA levels or the DNA -binding activity of AP1, AP2 and NF-kappa B in exponential cells during tr ansit to plateau-phase growth. Therefore, these results suggest that the ra diofrequency exposure is unlikely to elicit a general stress response in ce lls of this cell, line under these conditions, However, statistically signi ficant increases (similar to 2-fold, P = 0.001) in For mRNA levels were det ected in exponential cells in transit to the plateau phase and in plateau-p hase cells exposed to 835.62 MHz FMCW microwaves, For 847.74 MHz CDMA expos ure, the increase was 1.4-fold (P = 0.04). This increase in For expression suggests that expression of specific genes could be affected by radiofreque ncy exposure, (C) 1999 by Radiation Research Society.