ID Number		61
Study Type		In Vitro
Model		835.62 MHz (CDMA) exposure to cell lines and analysis of gene expression
Details		C3H 10T1/2 fibroblast cells were exposed to 835.62 MHz (FM) and 847.74 MHz (CDMA) signals at 0.6 W/kg for 1, 4, or 7 days, and expression of c-fos, c-jun, and c-myc mRNA was determined by rtPCR. No changes were observed for c-jun and c-myc expression. An initial 1.4 to 2 fold increase in c-fos expression was reported with exposure under all conditions of cell growth (log phase, transitional phase, or plateau phase). The researchers concluded that the change was real but not biologically relevant, especially in light of the lack of observable AP-1 DNA binding on gel shifts from the same cells. Follow-on studies, however, reported that the effects were not reproducible and that the frequency of false positives was as expected. No effect of CDMA or FM RF was observed (by gel shifts) on TATA, AP1, & NFkB. Both CDMA and FM RF exposure did, however, result in a 50% increase in the DNA binding activity of the AP2 factor. The authors again concluded that because of the small magnitude of increase as well as the lack of a concurrent elevation in AP1 in the same exposed groups of cells, the increase appeared to be either spurrious or not biologically relevant. An initial study (Goswami et al, 1997, Cell Proliferation 30:271-82) described the rtPCR assay to detect GAPDH and oncogene expression levels. Follow up studies using the same frequency and exposure system at 5 and 10 W/kg did not observe any elevation in c-fos mRNA levels using rtPCR in serum stimulated cells, thus not confirming the earlier reported effects. Additional studies following acute 24 hour exposures at 5 W/kg and analyzing RNA expression patterns with Affymetrix DNA chips (12,488 gene probe set) also reported no consistent significant changes in expression pattern. An initial study by Chen and Roti Roti looked at C3H 10T1/2 fibroblast cells exposed to 847 MHz (CDMA) for 1 or 7 days at 0.6 W/kg in a radial transmission line (RTL) exposure system. Identification of genes which are differentially expressed as a result of exposure was attempted using rtPCR amplification and differential display. No expressed gene differences between exposed and sham exposed cells were identified.
Findings		No Effects
Status		Completed With Publication
Principal Investigator		Washington University, USA - rotiroti@radonc.wustl.edu
Funding Agency		Motorola
Country		UNITED STATES
References		Whitehead, TD et al. Proteomics, (2006) 6:4739-4744 Whitehead, TD et al. Radiation Research., (2006) 165:626-635 , , () :- Whitehead, TD et al. Radiation Research, (2005) 164:420-430 Goswami, PC et al. Radiat. Res., (1999) 151:300-309 Goswami, PC et al. Cell Prolif, (1997) 30:271-282
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