Electric and magnetic noise blocks the 60 Hz magnetic field enhancement of steady state c-myc transcript levels in human leukemia cells

Abstract

We have previously demonstrated that exposure of human cultured cells to 60 Hz sinusoidal magnetic fields causes an increase in steady state transcript levels for the proto-oncogene c-myc. A study by Litovitz et al. (T.A. Litovitz D. Krause and J.M. Mullins, Biochem. Biophys. Res. Commun., 178(1991) 862) suggests that the induction of bioeffects from exposure to 60 Hz fields requires that the exposure field be coherent for some minimum length of time (approximately 10s). A related study demonstrated that these effects can be blocked by superposition of temporally incoherent magnetic noise fields. In this paper we investigate whether or not the superposition of a magnetic noise field can block the bioeffect of a coherent 60 Hz magnetic field on the transcript levels of the prooo-oncogene c-myc in HL60 cells. Experiments were performed using band-limited magnetic noise fields (30–90 Hz, 6.7 μT rms), and coherent 60 Hz magnetic fields (6.7 μT rms). The results show that exposure to the 60 Hz field alone produces approximately a 40% enhancement in the steady state level of the c-myc transcript. Superposition of the noise field on the 60 Hz field inhibited the enhancement of the c-myc transcript to the extent that no statistically significant was observed. This study provides additional proof of the coherence time requirement, and of the validity of the noise superposition method to block electric and magnetic field induced bioeffects.