Medical/biological study (experimental study)

Effect of 60 Hz magnetic fields on the activation of hsp70 promoter in cultured INER-37 and RMA E7 cells med./bio.

By: Heredia-Rojas JA, Rodriguez de la Fuente AO, Alcocer Gonzalez JM, Rodriguez-Flores LE, Rodriguez-Padilla C, Santoyo-Stephano MA, Castaneda-Garza E, Tamez-Guerra RS

Published in: In Vitro Cell Dev Biol Anim 2010; 46 (9): 758-763

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Aim of study (acc. to author)

To study the effect of a 60 Hz electromagnetic field on the activity of hsp70 promoter in cells transfected with the luciferase gene as reporter gene.

Background/further details

Experiments were carried out in five groups (for each cell line): 1) non-transfected cells as control (without magnetic field exposure or thermal treatment), 2) transfected cells but not exposed to the magnetic field or thermal treatment, 3) transfected cells treated with a thermal shock (43°C), 4) transfected cells exposed to the magnetic field at 8 µT, and 5) transfected cells exposed to the magnetic field at 80 µT. Five cell cultures were used for each treatment regimen and controls.

Endpoint

molecular biosynthesis: activity of hsp70 promoter: gene expression of luciferase gene

Exposure

- 50/60 Hz
- magnetic field

Exposure	Parameters
Exposure 1: 60 Hz Exposure duration: continuous for 20 min	magnetic flux density: 8 µT effective value magnetic flux density: 80 µT effective value

General information

cells were treated with i) 8 µT EMF ii) 80 µT EMF iii) 43° C heat shock

Exposure 1

Main characteristics

Frequency	60 Hz
Type	magnetic field
Waveform	sinusoidal
Exposure duration	continuous for 20 min

Exposure setup

Exposure source	solenoid
Setup	25 cm long solenoid with a radius of 5.27 cm and 340 turns of enamel isolated copper wire with a diameter of 1.3 mm placed inside a temperature-controlled incubator; cultures positioned in the middle of the solenoid where the magnetic field was homogeneous
Sham exposure	A sham exposure was conducted.

Parameters

Measurand	Value	Type	Method	Mass	Remarks
magnetic flux density	8 µT	effective value	measured	-	-
magnetic flux density	80 µT	effective value	measured	-	-

Additional parameter details

geomagnetic field: 20 µT (spatial average)

Exposed system:

intact cell/cell culture
INER-37 (human non-small-cell lung cancer cell line) and RMA E7 cells (E7-transfected mouse RMA lymphoma cells), transfected with the plasmid pEMF (electromagnetic field plasmid containing hsp70 promotor and the luciferase gene as reporter gene)

Methods Endpoint/measurement parameters/methodology

molecular biosynthesis: activity of hsp70 promoter: gene expression of luciferase gene (luciferase enzyme activity)

Investigated system:

cell lysates

Time of investigation:

after exposure

Main outcome of study (acc. to author)

The data showed an increased luciferase gene expression in INER-37 cells exposed to the magnetic field or thermal shock compared with controls, but the magnetic field exposure had no effect on the RMA E7 cell line.

Study character:

medical/biological study
experimental study
full/main study

Study funded by

Programa de Apoyo a la Investigación Científica y Tecnológica (PAICYT), Universidad Autonoma de Nuevo Leon (UANL), Mexico

Rodriguez-De la Fuente AO et al. (2012): Effect of 60 Hz electromagnetic fields on the activity of hsp70 promoter: an in vivo study
Mannerling AC et al. (2010): Effects of 50-Hz magnetic field exposure on superoxide radical anion formation and HSP70 induction in human K562 cells
Rodriguez de la Fuente AO et al. (2009): Effect of 60 Hz electromagnetic fields on the activity of hsp70 promoter: An in vitro study
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