ID Number		102
Study Type		In Vitro
Model		960 MHz (GSM) exposure to cell lines and analysis of growth
Details		Transformed human epithelial amnion cells were exposed to 960 MHz GSM for 20, 30, or 40 minutes at SARs 0.021, 0.21, and 2.1 mW/kg in a TEM cell. Proliferation, as determined by mitochondrial MTT (mitochondrial dehydrogenase enzyme) assay, was decreased at all 3 exposure levels in a manner seemingly dependent upon cumulative dose. In a follow-up study, cells held at temperatures of either 35 or 39 degrees in combination with RF exposure as above also showed similar proliferation changes, while temperature changes alone (sham exposure) were not reported to result in proliferation changes. Exposure was also reported to result in increased expression of hsp27 and hsp 70.
Findings		Effects
Status		Completed With Publication
Principal Investigator		University of Aarhus, Denmark - skwee@biokemi.au.dk
Funding Agency		Private/Instit.
Country		DENMARK
References		Kwee, S et al. Electro Magnetobiol , (2001) 20:141-152 Kwee, S et al. Bioelectrochem. & Bioenerg., (1998) 44:251-255 Velizarov, S et al. Bioelectrochem. & Bioenerg., (1999) 48:177-180
Comments		It is peculiar that maximal effects for decreased proliferation rate seemed to depend upon a cumulative total energy deposition level, and no clear exposure/response relationship between the various increasing exposure levels was observed at a given timepoint. Further, repeated periods of exposure did not seem to further decrease proliferation rate, suggesting that the cells somehow "acclimated" to the exposure effects once a threshold was reached. In the follow up study, the lack of an effect on proliferation at 35 or 39 degrees is also in contrast to other studies, including Higashikubo et al. The method for determining SAR values during exposure was not fully explained and there was no indication of appropriate temperature monitoring or characterization during exposure. Regarding the hsp27 and hsp70 findings, Cotgreave (2005) comments: "It is difficult to rationalize the results in terms of the kinetics of the responses reported, thus detracting from their use in extrapolations.... The data also lack any quantitative evaluation of the levels of HSP 70 using Western blotting in the culture as a whole."