Study type: Medical/biological study (experimental study)

Phosphorylation and gene expression of p53 are not affected in human cells exposed to 2.1425 GHz band CW or W-CDMA modulated radiation allocated to mobile radio base stations. med./bio.

Published in: Bioelectromagnetics 2006; 27 (6): 494-504

Aim of study (acc. to author)

To test the hypothesis that modulated radiofrequency fields from mobile radio base stations induce apoptosis or other cellular stress response that activate p53 or the p53-signaling pathway (and thus important regulators of apoptosis).

Background/further details

Phosphorylation of p53 is believed to be one of the mechanisms by which p53 is activated or stabilized in response to cell stress.
Cells treated with doxorubicin were used as positive controls for the induction of apoptosis and cells treated with doxorubicin or heat shock were used as positive controls for p53 phosphorylation and gene expression.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 2.1425 GHz
Exposure duration: continuous for 24 or 48 h
A172 cells
  • SAR: 80 mW/kg mean (correspondends to the ICNIRP limit for the average whole-body SAR value)
  • SAR: 250 mW/kg mean (correspondends to three times the ICNIRP limit for the average whole-body SAR value)
  • SAR: 800 mW/kg mean (correspondends to ten times the ICNIRP limit for the average whole-body SAR value)
Exposure 2: 2.1425 GHz
Exposure duration: continuous for 28 h
IMR-90 cells
Exposure 3: 2.1425 GHz
Modulation type: CW
Exposure duration: continuous for 24 or 48 h (A172) or 28 h (IMR-90)

Exposure 1

Main characteristics
Frequency 2.1425 GHz
Type
Exposure duration continuous for 24 or 48 h
Additional info A172 cells
Modulation
Modulation type cf. additional info
Additional info

The W-CDMA component of the IMT-2000 cellular system adopts Direct Sequence CDMA (DS-CDMA) and Frequency Division Duplex (FDD) as a multiple access and duplex scheme. The chip rate of the spread code is 3.84 megachip per second (Mcps).

Exposure setup
Exposure source
Setup The system allowed simultaneous exposure of 49 (7 x 7 array) 35-mm culture dishes with a similar SAR uniformity within each dish [Iyama et al., 2004]. Twelve dishes in the inner 25 culture dishes were used in this study.
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
SAR 80 mW/kg mean - - correspondends to the ICNIRP limit for the average whole-body SAR value
SAR 250 mW/kg mean - - correspondends to three times the ICNIRP limit for the average whole-body SAR value
SAR 800 mW/kg mean - - correspondends to ten times the ICNIRP limit for the average whole-body SAR value

Exposure 2

Main characteristics
Frequency 2.1425 GHz
Type
Exposure duration continuous for 28 h
Additional info IMR-90 cells
Modulation
Modulation type cf. additional info
Additional info

The W-CDMA component of the IMT-2000 cellular system adopts Direct Sequence CDMA (DS-CDMA) and Frequency Division Duplex (FDD) as a multiple access and duplex scheme. The chip rate of the spread code is 3.84 megachip per second (Mcps).

Exposure setup
Exposure source
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
SAR 80 mW/kg mean - - ±47%

Exposure 3

Main characteristics
Frequency 2.1425 GHz
Type
Exposure duration continuous for 24 or 48 h (A172) or 28 h (IMR-90)
Modulation
Modulation type CW
Exposure setup
Exposure source
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
SAR 80 mW/kg mean - - ±47%

Reference articles

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated material:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

The data showed that p53 phosphorylation in the two cell lines investigated is not induced by exposure to 2.1425 GHz W-CDMA or CW signal. Moreover, changes in expression levels of the p53 protein and p53-related genes, and the frequency of apoptotis were not induced by any of the radiofrequency exposures.

Study character:

Study funded by

Related articles