Study type: Medical/biological study (experimental study)

Radiofrequency radiation (900 MHz) induces Egr-1 gene expression and affects cell-cycle control in human neuroblastoma cells. med./bio.

Published in: J Cell Physiol 2007; 213 (3): 759-767

Aim of study (acc. to editor)

This study was conducted to determine the effects of a 900 MHz-modulated radio frequency field on viability in human neuroblastoma cells in vitro.

Background/further details

The cell viability was assessed by cell proliferation, cell cycle progression, expression studies of genes involved in cell proliferation and apoptosis (egr-1, p53, apoptosis inhibitor: bcl-2, survivin) up to chrarcterization of molecular processes via enzyme activity. The investigated transcription factor egr-1 is a gene essential for cell proliferation, cell differentiation, and apoptosis. Increased egr-1 expression and the induced Egr-1 protein is a strong transcriptional activator of key genes involved in cell death pathway.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 900 MHz
Modulation type: pulsed
Exposure duration: continuous for 5, 15, 30 min, 6 or 24 h

General information

Lovisolo GA, Asta D, Ciammetti L, Mancini S, Marino C, Pinto R, D'Inzeo G. 2000. In vitro exposure system operating at 900 and 1800 MHz. In: Kostarakis P, Stavroulakis P, editors. Proceeding of Millennium International Workshop on Biological Effects of Electromagnetic field. Heraklion, Crete, Greece, 17-20 October, pp 169-175.

Exposure 1

Main characteristics
Frequency 900 MHz
Type
Exposure duration continuous for 5, 15, 30 min, 6 or 24 h
Modulation
Modulation type pulsed
Duty cycle 12.5 %
Additional info

GSM modulated

Exposure setup
Exposure source
Chamber The RF exposure system was based on a wire patch cell (WPC) antenna [Laval et al., 2000] and assembled as described in [Lovisolo et al., 2000]. Two WPCs were located in the same incubator for blinded RF and sham exposure. The absence of any interference between the two WPCs was experimentally confirmed.
Sham exposure A sham exposure was conducted.
Additional info Sixteen hours prior to RF exposure, cells in logarithmic growth were aliquoted from a single parental flask into individual 35-mm Petri dishes. The temperature of the dishes was maintained at 37 ± 1 °C by an appropriate cooling system [Ardoino et al., 2004]. The exposure system was turned on at least 30 min before the experiment, and the temperature in the incubator was monitored with a thermocouple probe (sensitivity ± 0.1 °C) during the exposure.
Parameters
Measurand Value Type Method Mass Remarks
electric field strength 23 V/m effective value calculated - -
SAR 1 W/kg mean calculated - -

Reference articles

Exposed system:

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

The exposure to radiofrequency field for 24 hours exerted a significant reduction in cell viability and cell proliferation. Within exposure the egr-1- gene expression increased in 5 minutes, reaching maximum after 15 minutes, and decline to baseline levels after 6 hours. The enzyme activities of the MAPK subtypes showed similar pattern.
Cells exposed for 24 hours exhibited cell cycle progress typical for apoptosis accompanied by significant decreased gene expression of the investigated apoptosis inhibitor bcl-2 and survivin.

Study character:

Study funded by

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