Medical/biological study (experimental study)

Effects of extremely low-frequency electromagnetic fields on delayed chromosomal instability induced by bleomycin in normal human fibroblast cells med./bio.

By: Cho YH, Jeon HK, Chung HW

Published in: J Toxicol Environ Health A 2007; 70 (15-16): 1252-1258

Aim of study (acc. to author)

To study the interaction of extremely low frequency electromagnetic fields on delayed chromosomal instability (with and without bleomycin) in human fibroblast cells.

Background/further details

Electromagnetic fields of 0.8 mT field strength was applied either alone or with bleomycin throughout the culture period. The frequencies of micronuclei and aneuploidy were analyzed at 28, 88, and 240 h after bleomycin treatment.

Endpoint

genotoxicity/mutation: chromosomal instability (of chromosome 1 and 4)

Exposure

- co-exposure

Exposure	Parameters
Exposure 1: 60 Hz Exposure duration: continuous throughout the cultivation period	magnetic flux density: 0.8 mT

General information

cells were treated: i) with sham EMF exposure ii) with EMF exposure iii) with EMF exposure and bleomycin

Exposure 1

Main characteristics

Frequency	60 Hz
Type	magnetic field
Exposure duration	continuous throughout the cultivation period

Exposure setup

Exposure source	solenoid
Setup	two solenoids, each 0.3 m long with a diameter of 0.15 m and 350 turns/m of number 16 bifilar magnet wire
Sham exposure	A sham exposure was conducted.

Parameters

Measurand	Value	Type	Method	Mass	Remarks
magnetic flux density	0.8 mT	-	-	-	-

Reference articles

Walleczek J et al. (1999): Increase in radiation-induced HPRT gene mutation frequency after nonthermal exposure to nonionizing 60 Hz electromagnetic fields

Exposed system:

intact cell/cell culture
CCD-986sk (human fibroblasts)

Methods Endpoint/measurement parameters/methodology

genotoxicity/mutation: chromosomal instability (of chromosome 1 and 4; cytokinesis block micronucleus assay; aneuploidy; fluorescence in situ hybridization)

Investigated system:

Time of investigation:

after exposure

Main outcome of study (acc. to author)

The co-exposure (bleomycin and electromagnetic field) led to a significant increase in the frequencies of micronuclei and aneuploidy compared to the cells treated with bleomycin alone.
However, no difference was found between electromagnetic field exposed and sham exposed control cells.
The frequency of micronuclei induced by bleomycin was increased at 28 h, and persistently increased up to 240 h, but the new levels were not significantly different from the level at 28 h (= no delayed chromosomal instability by electromagnetic fields). Bleomycin alone increased the frequencies of aneuploidy at 28, 88, and 240 h, and significantly higher frequency of aneuploidy was found in the cells analyzed at 240 h compared to the cells examined at 28 h.
The data suggest that the extremely low frequency electromagnetic field enhances the cytotoxicity of bleomycin. Bleomycin might induce delayed chromosomal instability, but no effect of extremely low frequency electromagnetic field was found on the bleomycin-induced delayed chromosomal instability in fibroblast cells.

Study character:

medical/biological study
experimental study
full/main study
blind study

Study funded by

Korea Research Foundation (KRF), Korea

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