Study type: Medical/biological study (experimental study)

ELF-MF exposure affects the robustness of epigenetic programming during granulopoiesis. med./bio.

Published in: Sci Rep 2017; 7: 43345

Aim of study (acc. to author)

To investigate the potential effect of a 50 Hz magnetic field on epigenetic modifications in Jurkat cells and human haematopoietic stem cells during granulopoiesis.

Background/further details

Extremely low frequency magnetic fields have been associated with an increased risk of childhood leukemia. However, no underlying mechanism of action has been found to date, which could explain the development of leukemia due to weak magnetic fields. The authors of the present study reasoned that magnetic fields may influence epigenetics rather than the genome and that these epigenetic alterations could affect cancer promotion.
Granulopoiesis is haematopoiesis of granulocytes.
A positive control was conducted with the histone deacetylation inhibitor trichostatin A (TSA), which is a known epigenetic modulator.
Two to three repetitions were performed.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 50 Hz
Exposure duration: intermittent (5 min on, 10 min off) for 72 hours

Exposure 1

Main characteristics
Frequency 50 Hz
Type
Waveform
Exposure duration intermittent (5 min on, 10 min off) for 72 hours
Exposure setup
Exposure source
Setup each coil was placed inside a µ metal box; these boxes were placed side by side in the same incubator to decouple the coils and to shield the electric and magnetic fields from the incubator as well as to ensure the same environmental conditions (temperature, humidity and CO2); magnetic field uniformity was >1% (standard deviation)
Sham exposure A sham exposure was conducted.
Additional info magnetic field during sham exposure was <7 μT
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 1 mT - - - -

Exposed system:

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

In both cell lines, no significant differences were observed between exposed and sham exposed cells regarding proliferation, cell cycle distribution, number of living, apoptotic and necrotic cells, and cell differentiation.
In Jurkat cells, no significant differences were found between exposed and sham exposed cells regarding the occurrence of the key histone marks H3K4me2 and H3K27me3. Similarly, in stem cells, magnetic field exposure did not reproducibly influence the histone modification pattern and the formation of cell-type specific DNA methylation pattern. However, magnetic field exposure significantly reduced the variability of histone modifications and DNA methylation particularly in differentiating cells and increased the robustness of histone modifications and DNA methylation.
The authors conclude that exposure of Jurkat cells and hematopoietic stem cells to a 50 Hz magnetic field could stabilize active chromatin, especially during cell differentiation.

Study character:

Study funded by

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