Study type: Medical/biological study (experimental study)

Extremely Low-Frequency Electromagnetic Fields Cause G1 Phase Arrest through the Activation of the ATM-Chk2-p21 Pathway. med./bio.

Published in: PLoS One 2014; 9 (8): e104732

Aim of study (acc. to author)

To investigate the biological effects of exposure to extremely low frequency magnetic fields in HaCaT cells at the transcriptional, protein and cellular level.

Background/further details

Ionizing radiation (UV-B, 233 J/m²) was performed as a positive control.
Further controls were performed using siRNA (small interfering RNA), which is a class of double-stranded RNA molecules, 20-25 base pairs in length and do not code for proteins. It is most notable in the interference of the expression of specific genes with complementary nucleotide sequences resulting in a prevention of translation.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 60 Hz
Exposure duration: continuous up to 144 hours (24, 48, 72, 96, 120, 144 hours)

Exposure 1

Main characteristics
Frequency 60 Hz
Type
Exposure duration continuous up to 144 hours (24, 48, 72, 96, 120, 144 hours)
Exposure setup
Exposure source
Setup pair of coil apparatuses each had a diameter of 34 cm and were 17 cm apart. AC power to the Helmholtz coil system was supplied by a step-down transformer connected to a 60-Hz, 110 V AC source
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 1.5 mT - measured - ± 0.03 µT, in the central area of the coils

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

In 144 hours-exposed cell cultures, the number of cells in the G1 phase was significant increased ("G1 phase cell cycle arrest") compared to the sham exposure, while the cell proliferation and colony forming units were significantly decreased. The protein expression of phosphorylated ATM, phosphorylated Chk2 and p21 was higher in the exposed cell cultures (after 96, 120 and 144 hours) than in the sham exposed ones. The magnetic field-induced G1 phase cell cycle arrest was diminished when the gene expression of CHK2 was prevented by transfection with the siRNA.
The authors conclude that extremely low frequency magnetic fields can trigger cell cycle arrest in the G1 phase in HaCaT cells. Furthermore, they conclude that the results indicate an involvement of an ATM-Chk2-p21 pathway.

Study character:

Study funded by

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