Study type: Medical/biological study (experimental study)

Effects of extremely low-frequency electromagnetic field on expression levels of some antioxidant genes in human MCF-7 cells. med./bio.

Published in: Mol Biol Res Commun 2016; 5 (2): 77-85

Aim of study (acc. to author)

The effects of exposure of human breast cancer cells to a 50 Hz magnetic field on the gene expression of 7 antioxidant genes should be investigated.

Background/further details

Cells were divided into the following groups: 1) intermittent exposure to the 0.25 mT magnetic field with 5 min on/5 min off conditions, 2) intermittent exposure to the 0.25 mT magnetic field with 15 min on/15 min off conditions, 3) continuous exposure to the 0.25 mT magnetic field, 4) intermittent exposure to the 0.5 mT magnetic field with 5 min on/5 min off conditions, 5) intermittent exposure to the 0.5 mT magnetic field with 15 min on/15 min off conditions, 6) continuous exposure to the 0.5 mT magnetic field. For each exposure group, a separate sham exposure group was used.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 50 Hz
Exposure duration: intermittent 5 min on/5 min off for 30 minutes
Exposure 2: 50 Hz
Exposure duration: intermittent 15 min on/15 min off for 30 minutes
Exposure 3: 50 Hz
Exposure duration: continuous for 30 minutes
Exposure 4: 50 Hz
Exposure duration: intermittent 5 min on/5 min off for 30 minutes
Exposure 5: 50 Hz
Exposure duration: intermittent 15 min on/15 min off for 30 minutes
Exposure 6: 50 Hz
Exposure duration: continuous for 30 minutes

Exposure 1

Main characteristics
Frequency 50 Hz
Type
Waveform
Exposure duration intermittent 5 min on/5 min off for 30 minutes
Exposure setup
Exposure source
Chamber petri dishes
Setup solenoid with 44 cm length and 14 cm diameter consisted of 200 turns of 1 mm diameter copper wire, which was wounded in two layers; it was placed in a box shielded with 2 layers of aluminum and 1 layer of copper; dishes were located on the axis of the solenoid for an almost uniform exposure; temperature changes were monitored during exposure and no change was observed
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 0.25 mT - measured and calculated - -

Exposure 2

Main characteristics
Frequency 50 Hz
Type
Waveform
Exposure duration intermittent 15 min on/15 min off for 30 minutes
Exposure setup
Exposure source
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 0.25 mT - measured and calculated - -

Exposure 3

Main characteristics
Frequency 50 Hz
Type
Waveform
Exposure duration continuous for 30 minutes
Exposure setup
Exposure source
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 0.25 mT - measured and calculated - -

Exposure 4

Main characteristics
Frequency 50 Hz
Type
Waveform
Exposure duration intermittent 5 min on/5 min off for 30 minutes
Exposure setup
Exposure source
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 0.5 mT - measured and calculated - -

Exposure 5

Main characteristics
Frequency 50 Hz
Type
Waveform
Exposure duration intermittent 15 min on/15 min off for 30 minutes
Exposure setup
Exposure source
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 0.5 mT - measured and calculated - -

Exposure 6

Main characteristics
Frequency 50 Hz
Type
Waveform
Exposure duration continuous for 30 minutes
Exposure setup
Exposure source
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 0.5 mT - measured and calculated - -

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

Several significantly differently expressed genes were found in exposure groups compared to respective sham exposed cells, with group 4 (15 min on/15 min off, 0.5 mT) showing the most genes with differential expression.
Moreover, gene expression was significantly different between 0.25 mT and 0.5 mT fields in intermittent 15 min on/15 min off conditions (groups 2 and 4, respectively).
There were no differences found in cell viability between exposure groups and the respective sham exposure groups.
The authors conclude that exposure of human breast cancer cells to a 50 Hz magnetic field might have an effect on the gene expression of some antioxidant genes.

Study character:

Study funded by

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