Medical/biological Study (experimental study)

Induction of adaptive response in human blood lymphocytes exposed to 900 MHz radiofrequency fields: Influence of cell cycle. med./biol.

PubMed Entry

Journal web site

Aim of study (according to author)
To study the influence of the cell cycle on the adaptive response induced by the exposure of human blood lymphocytes to radiofrequency fields.
Background/further details:
Adaptive response: Different cell types that were exposed to an extremely small adaptation dose of a genotoxic agent were found to be less susceptible to the induction of genetic damage when given a higher challenge dose of the same or similar genotoxic agent. The induction of an adaptive response was shown to be influenced by several factors (e.g. the dose used for adaptation, the dose rate, the time between the adaptation and challenge doses).
Human peripheral blood lymphocytes in G₀ phase, G₁ phase or S phase of the cell cycle were exposed for 20 hours to an adaptive dose of 900 MHz radiofrequency and then treated with a challenge dose of 100 ng/ml mitomycin C.
Lymphocytes of nine different healthy male donors were investigated.

Endpoint

• genotoxicity/mutation: DNA damage (micronucleus formation)

Exposure
General category: mobile communication system, mobile phone, GSM, radio frequency field

Field characteristics	Parameters
900 MHz exposure duration: continuous for 20 h	SAR: 1.25 W/kg average over time SAR: 10 W/kg peak value

Exposed system:
intact cell/cell culture (in vitro)

Methods
Endpoint/Measurement parameters/Methodology

• genotoxicity/mutation: micronucleus formation (cytokinesis block micronucleus assay; Giemsa stain; light microscopy)
• cell viability/cell division/proliferation: cytotoxicity (proliferation index (M1+2M2+3(M3+M4)/total number of cells; M1 to M4: number of cells with 1 to 4 nuclei); binucleate cell index (percentage of binucleated cells))

Main outcome of study (according to author)
The data indicated that the cells which were exposed to an adaptive dose of radiofrequency in G₀ phase and G₁ phase of the cell cycle did not exhibit an adaptive response while such a response was observed when the cells were exposed to an adaptive dose of radiofrequency in the S phase of the cell cycle.
These findings confirmed the observations reported in previous investigations (Sannino et al. 2009) where an adaptive response was found in human blood lymphocytes exposed to an adaptive dose of radiofrequency in S phase of the cell cycle and further suggested that the timing of an adaptive dose exposure of radiofrequency is important to elicit an adaptive response.

(Study character: medical/biological study, experimental study, full/main study)

Study funded by

• not stated/none

• Karaca E et al. (2012): The genotoxic effect of radiofrequency waves on mouse brain.
• Hintzsche H et al. (2012): 900 MHz radiation does not induce micronucleus formation in different cell...
• Jiang B et al. (2012): Adaptive Response in Mice Exposed to 900 MHz Radiofrequency Fields: Primary DNA...
• Zeni O et al. (2012): Induction of an adaptive response in human blood lymphocytes exposed to...
• Maaroufi K et al. (2011): Oxidative stress and prevention of the adaptive response to chronic iron...
• Cao Y et al. (2011): Induction of adaptive response: pre-exposure of mice to 900 MHz radiofrequency...
• Hansteen IL et al. (2009): Cytogenetic effects of 18.0 and 16.5 GHz microwave radiation on human...
• Sannino A et al. (2009): Induction of adaptive response in human blood lymphocytes exposed to...
• Hansteen IL et al. (2009): Cytogenetic effects of exposure to 2.3 GHz radiofrequency radiation on human...
• Zeni O et al. (2008): Evaluation of genotoxic effects in human leukocytes after in vitro exposure to...
• Vijayalaxmi et al. (2008): Genetic damage in mammalian somatic cells exposed to radiofrequency radiation:...
• Scarfi MR et al. (2006): Exposure to radiofrequency radiation (900 MHz, GSM signal) does not affect...