Medical/biological study (experimental study)

Exposure of mcf-7 breast cancer cells to electromagnetic fields up-regulates the plasminogen activator system med./bio.

By: Girgert R, Emons G, Hanf V, Gründker C

Published in: Int J Gynecol Cancer 2009; 19 (3): 334-338

Aim of study (acc. to author)

To study the effects of low frequency electromagnetic fields on the plasminogen activator system in two different MCF-7 breast cancer cell lines.

Background/further details

The plasminogen activator system is involved in the degradation of the extracellular matrix (important process of the multiple steps of apoptosis).

Endpoint

molecular biosynthesis: gene expression (of four genes of the plasminogen activator system)

Exposure

Exposure	Parameters
Exposure 1: 50 Hz Exposure duration: continuous for 48 hr or 96 hr	magnetic flux density: 1.2 µT

Exposure 1

Main characteristics

Frequency	50 Hz
Type	magnetic field
Waveform	sinusoidal
Exposure duration	continuous for 48 hr or 96 hr

Exposure setup

Exposure source	coil(s)
Setup	homogeneous field: variation less than 5 %; 75 cm long copper tube with a diameter of 30 cm, closed on either end with a copper plate; a bifiliar wire wrapped around the tube for heating; on top of this a second layer of wiring was wound and connected to a signal generator
Sham exposure	A sham exposure was conducted.

Parameters

Measurand	Value	Type	Method	Mass	Remarks
magnetic flux density	1.2 µT	-	-	-	-

Exposed system:

intact cell/cell culture
MCF-7 (breast cancer cell line, p40 and p181 clone)

Methods Endpoint/measurement parameters/methodology

molecular biosynthesis: gene expression (of four genes of the plasminogen activator system (urokinase plasminogen activator, plasminogen activator inhibitor-1, receptor for urokinase plasminogen activator, tissue plasminogen activator); RT-PCR)
cell viability/cell division/proliferation: cell density, cell viability

Investigated system:

DNA/RNA
intact cell/cell culture

Time of investigation:

after exposure

Main outcome of study (acc. to author)

In MCF-7 cells exposed to 1.2 µT electromagnetic field gene expression of the urokinase plasminogen activator gene and of plasminogen activator inhibitor-1 was markedly increased. The gene expression of the receptor for urokinase plasminogen activator was only marginally increased in one of the two cell lines and expression of the tissue plasminogen activator was at least slightly down-regulated in exposed breast cancer cells.
The data showed that environmental electromagnetic fields increase the expression of important genes of the plasminogen activator system. The increased expression of urokinase plasminogen activator gene and of plasminogen activator inhibitor-1 may cause a higher metastatic potential of breast tumors.

Study character:

medical/biological study
experimental study
full/main study

Study funded by

Bundesministerium für Umwelt, Naturschutz und Reaktorsicherheit (Federal Ministry of the Environment, Nature Conservation, and Nuclear Safety), Germany

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