ENHANCEMENT OF ANCHORAGE-INDEPENDENT GROWTH IN JB6 CELLS EXPOSED TO 60 HERTZ MAGNETIC-FIELDS

Extremely low frequency electromagnetic fields (EMFs) are implicated i n the genesis of childhood leukemias and lymphomas after residential e xposure, and of tumors in adults after occupational exposure. Experime nts in vitro have demonstrated biochemical changes with cultured cells including modulation of signal transduction pathways. We examined the ability of 60 Hz sinusoidal EMFs to alter the growth of a promotion-s ensitive mouse epidermal cell line (JB6) under anchorage-independent c onditions. Cells (10(4) per dish) were suspended in 0.3% agar in 60 mm dishes and exposed to a 1.1 X 10(-3) T field generated by a Helmholtz coil held in an incubator at 37 degrees C, 5% CO2 and 90%-97% relativ e humidity. Growth of colonies more than 60 mu m in diameter was score d after 10-14 days. Exposure to the EMF significantly increased the co lony-forming efficiency, by 40%-70% compared with control cells(> 95% confidence level), suggesting interaction with a growth control/signal transduction pathway.