Study type: Medical/biological study (experimental study)

Gene expression changes in human cells after exposure to mobile phone microwaves. med./bio.

Published in: Proteomics 2006; 6 (17): 4745-4754

Aim of study (acc. to editor)

To study the effects of microwaves emitted by mobile phones on gene expression patterns in human cells.

Background/further details

Six human cell types, immortalized cell lines and primary cells, were exposed. Immortalized cell lines can be standardized, but they are different from primary cells or even genetically instable. This can lead to changes in apoptosis, cell proliferation, and cell differentiation.
The work is part of the REFLEX project (Risk Evaluation of Potential Environmental Hazards From Low Energy Electromagnetic Field Exposure Using Sensitive in vitro Methods), funded by the European Union.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 1,800 MHz
Modulation type: pulsed
Exposure duration: intermittent, 5 min on/10 min off, for 24 h
NB69 cells
Exposure 2: 1,800 MHz
Modulation type: pulsed
Exposure duration: continuous for 1 h
E.A.hy926 cells
  • SAR: 2.5 W/kg (1.8-2.5 W/kg)
Exposure 3: 1,800 MHz
Modulation type: pulsed
Exposure duration: intermittent, 10 min on/20 min off, for 44 h
  • SAR: 1.4 W/kg
Exposure 4: 1,800 MHz
Modulation type: pulsed
Exposure duration: intermittent, 5 min on/5 min off, for 24 h
Exposure 5: 1,800 MHz
Modulation type: pulsed
Exposure duration: continuous for 24 h
  • SAR: 1.3 W/kg
Exposure 6: 900 MHz
Modulation type: pulsed
Exposure duration: continuous for 1 h
E.A.hy926 cells
  • SAR: 2.5 W/kg (1.8-2.5 W/kg)
Exposure 7: 900 MHz
Modulation type: pulsed
Exposure duration: continuous for 1 h
U937 and CHME5 cells

Exposure 1

Main characteristics
Frequency 1,800 MHz
Type
Charakteristic
  • guided field
Exposure duration intermittent, 5 min on/10 min off, for 24 h
Additional info NB69 cells
Modulation
Modulation type pulsed
Pulse width 576 µs
Rise time 15 µs
Fall time 15 µs
Duty cycle 12.5 %
Repetition frequency 217 Hz
Additional info

GSM basic mode with every 26th frame idle which adds an 8-Hz modulation component to the signal

Exposure setup
Exposure source
Chamber Two single-mode cavities equipped with a fan were placed inside a CO2 incubator. Exposure and sham conditions were blindly assigned by the computer-controlled signal unit. Monopole antennas were integrated to monitor and control the incident field.
Setup Six 35-mm Petri dishes were placed in each waveguide in a dish holder holding them in the H-field maximum of the standing wave. The system enabled the exposure of monolayers of cells with an SAR non-uniformity of less than 30%.
Sham exposure A sham exposure was conducted.
Additional info The air flow temperature monitored with accurate Pt100 probes showed differences of less than 0.1°C between exposed and sham waveguides. A numerical heat flow analysis showed that hot spots inside the medium could be excluded.
Parameters
Measurand Value Type Method Mass Remarks
SAR 2 W/kg - measured and calculated - -

Exposure 2

Main characteristics
Frequency 1,800 MHz
Type
Charakteristic
  • guided field
Exposure duration continuous for 1 h
Additional info E.A.hy926 cells
Modulation
Modulation type pulsed
Pulse width 576 µs
Rise time 15 µs
Fall time 15 µs
Duty cycle 12.5 %
Repetition frequency 217 Hz
Additional info

GSM basic mode

Exposure setup
Exposure source
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
SAR 2.5 W/kg - measured and calculated - 1.8-2.5 W/kg

Exposure 3

Main characteristics
Frequency 1,800 MHz
Type
Charakteristic
  • guided field
Exposure duration intermittent, 10 min on/20 min off, for 44 h
Additional info T-lymphocytes
Modulation
Modulation type pulsed
Pulse width 576 µs
Rise time 15 µs
Fall time 15 µs
Duty cycle 12.5 %
Repetition frequency 217 Hz
Additional info

GSM basic mode

Exposure setup
Exposure source
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
SAR 1.4 W/kg - measured and calculated - -

Exposure 4

Main characteristics
Frequency 1,800 MHz
Type
Charakteristic
  • guided field
Exposure duration intermittent, 5 min on/5 min off, for 24 h
Additional info HL-60 cells
Modulation
Modulation type pulsed
Pulse width 576 µs
Rise time 15 µs
Fall time 15 µs
Duty cycle 12.5 %
Repetition frequency 217 Hz
Additional info

GSM DTX mode

Exposure setup
Exposure source
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
SAR 1 W/kg - measured and calculated - -

Exposure 5

Main characteristics
Frequency 1,800 MHz
Type
Charakteristic
  • guided field
Exposure duration continuous for 24 h
Additional info HL-60 cells
Modulation
Modulation type pulsed
Pulse width 576 µs
Rise time 15 µs
Fall time 15 µs
Duty cycle 12.5 %
Repetition frequency 217 Hz
Additional info

GSM DTX mode

Exposure setup
Exposure source
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
SAR 1.3 W/kg - measured and calculated - -

Exposure 6

Main characteristics
Frequency 900 MHz
Type
Charakteristic
  • guided field
Exposure duration continuous for 1 h
Additional info E.A.hy926 cells
Modulation
Modulation type pulsed
Pulse width 576 µs
Rise time 15 µs
Fall time 15 µs
Duty cycle 12.5 %
Repetition frequency 217 Hz
Additional info

GSM basic mode

Exposure setup
Exposure source
Chamber The exposure chamber was positioned vertically inside a cell culture incubator.
Setup Two 55-mm glass Petri dishes were placed in such a way that the E-field vector was parallel to the plane of the culture medium.
Sham exposure A sham exposure was conducted.
Additional info Temperature-controlled water was circulated through a thin (9 mm) rectangular glass fibre moulded waterbed underneath the Petri dishes [Leszczynski et al., 2002].
Parameters
Measurand Value Type Method Mass Remarks
SAR 2.5 W/kg - measured and calculated - 1.8-2.5 W/kg

Exposure 7

Main characteristics
Frequency 900 MHz
Type
Charakteristic
  • guided field
Exposure duration continuous for 1 h
Additional info U937 and CHME5 cells
Modulation
Modulation type pulsed
Pulse width 576 µs
Rise time 15 µs
Fall time 15 µs
Duty cycle 12.5 %
Repetition frequency 217 Hz
Additional info

GSM basic mode

Exposure setup
Exposure source
  • wire patch cell [Laval et al., 2000], PIOM/IT'IS exposure setup for U937 and CHME5 cells
Setup The wire patch cell (WPC) accommodated eight 3.5-cm Petri dishes in the following way: Each Petri dish was positioned inside a 5-cm outer dish filled with distilled water. Two of these double Petri dishes were piled up, and four of these stacks were placed in the WPC.
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
SAR 2 W/kg - measured and calculated - -

Reference articles

  • Leszczynski D et al. (2002): Non-thermal activation of the hsp27/p38MAPK stress pathway by mobile phone radiation in human endothelial cells: Molecular mechanism for cancer- and blood-brain barrier-related effects.
  • Laval L et al. (2000): A new in vitro exposure device for the mobile frequency of 900 MHz.
  • Moros EG et al. (1999): On the assumption of negligible heat diffusion during the thermal measurement of a nonuniform specific absorption rate.

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

Exposed CHME5 microglial cells, NB69 neuroblastoma cells, and T lymphocytes did not show significant changes in gene expression.
In HL-60 leukemia cells, EA.hy926 endothelial cells, and U937 lymphoblastoma cells between 12 and 34 up-regulated or down-regulated genes were found. Changes depended on cell type and radiofrequency electromagnetic field signal. Analysis of the affected gene families did not point towards a stress response. However, following microwave irradiation, some but not all human cells might react with an increase in expression of genes encoding ribosomal proteins and therefore up-regulating the cellular metabolism.

Study character:

Study funded by

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