Study type: Medical/biological study (experimental study)

ERK1/2 phosphorylation, induced by electromagnetic fields, diminishes during neoplastic transformation. med./bio.

Published in: J Cell Biochem 2000; 78 (3): 371-379

Aim of study (acc. to author)

The question whether an extremely low frequency electromagnetic field can act as co-promoter during neoplastic transformation should be clarified in mouse cells in vitro.

Background/further details

The cell line used could be modified in its transformation status. Adding of retinyl acetate leads to suppression of the cell transformation thus affording the cell examination at three stages: 1. before initiation of transformation, 2. early in the transformation, and 3. at full of transformation.
TPA treated cells were used as positive control.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 60 Hz
Exposure duration: up to 180 min continuous

General information

Cells were exposed: i) during suppression of neoplastic phenotype ii) 4 days after withdrawal of RAC iii) during full neoplastic transformation

Exposure 1

Main characteristics
Frequency 60 Hz
Type
Waveform
Exposure duration up to 180 min continuous
Exposure setup
Exposure source
Chamber 100 mm Petri dishes on Plexiglas stand, horizontal orientation
Setup coils consisting of 164 turns of 19-gauge wire on a square form (13 cm long, 14 cm wide) with 8 cm spacing; coils shielded in µ-metal containers
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
electric field strength 11 µV/m - calculated - for 8µT
magnetic flux density 300 µT maximum measured - 0.8, 8, 80, 300 µT

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • before exposure
  • during exposure
  • after exposure

Main outcome of study (acc. to author)

The exposure to electromagnetic field induced significant increases in Hsp70, c-Fos levels and in AP-1 DNA binding activation in non-transformed cells (stage 1). These effects reduced in transformed cells.
Phosphorylation of mitogen-activated protein kinase was most pronounced before the onset of transformation, but this increase diminished during the transformation process. No changes in phosphorylation of the stress-activated protein kinase was detected in cells exposed to electromagnetic fields at any transformation stage.
The results of the examined parameters indicate that electromagnetic fields did not affect the cell transformation rate or acted as a co-promoter.

Study character:

Study funded by

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