915 MHz microwaves and 50 Hz magnetic field affect chromatin conformation and 53BP1 foci in human lymphocytes from hypersensitive and healthy persons.
We used exposure to microwaves from a global system for mobile communication (GSM) mobile phone (915 MHz, specific absorption rate (SAR) 37 mW/kg) and power frequency magnetic field (50 Hz, 15 muT peak value) to investigate the response of lymphocytes from healthy subjects and from persons reporting hypersensitivity to electromagnetic field (EMF). The hypersensitive and healthy donors were matched by gender and age and the data were analyzed blind to treatment condition. The changes in chromatin conformation were measured with the method of anomalous viscosity time dependencies (AVTD). 53BP1 protein, which has been shown to colocalize in foci with DNA double strand breaks (DSBs), was analyzed by immunostaining in situ. Exposure at room temperature to either 915 MHz or 50 Hz resulted in significant condensation of chromatin, shown as AVTD changes, which was similar to the effect of heat shock at 41 degrees C. No significant differences in responses between normal and hypersensitive subjects were detected. Neither 915 MHz nor 50 Hz exposure induced 53BP1 foci. On the contrary, a distinct decrease in background level of 53BP1 signaling was observed upon these exposures as well as after heat shock treatments. This decrease correlated with the AVTD data and may indicate decrease in accessibility of 53BP1 to antibodies because of stress-induced chromatin condensation. Apoptosis was determined by morphological changes and by apoptotic fragmentation of DNA as analyzed by pulsed-field gel electrophoresis (PFGE). No apoptosis was induced by exposure to 50 Hz and 915 MHz microwaves. In conclusion, 50 Hz magnetic field and 915 MHz microwaves under specified conditions of exposure induced comparable responses in lymphocytes from healthy and hypersensitive donors that were similar but not identical to stress response induced by heat shock.
Belyaev
Igor Y
IY
Department of Genetics, Microbiology and Toxicology, Stockholm University, S-106 91 Stockholm, Sweden. Igor.Belyaev@gmt.su.se
Hillert
Lena
L
Protopopova
Marina
M
Tamm
Christoffer
C
Malmgren
Lars O G
LO
Persson
Bertil R R
BR
Selivanova
Galina
G
Harms-Ringdahl
Mats
M
D000328:Adult; D017209:Apoptosis / Q000528:radiation effects; D040421:Cell Phone; D002478:Cells, Cultured; D002843:Chromatin / Q000528:radiation effects; D004249:DNA Damage; D004574:Electromagnetic Fields; D018869:Heat-Shock Response / Q000528:radiation effects; D006801:Humans; D006967:Hypersensitivity / Q000097:blood* / Q000378:metabolism* / Q000473:pathology; D066298:In Vitro Techniques; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism*; D008214:Lymphocytes / Q000378:metabolism* / Q000473:pathology / Q000528:radiation effects*; D008297:Male; D008872:Microwaves; D008875:Middle Aged; D009690:Nucleic Acid Conformation / Q000528:radiation effects; D010750:Phosphoproteins / Q000378:metabolism*; D016037:Single-Blind Method; D000071857:Tumor Suppressor p53-Binding Protein 1
D002843:Chromatin; D047908:Intracellular Signaling Peptides and Proteins; D010750:Phosphoproteins; C498301:TP53BP1 protein, human; D000071857:Tumor Suppressor p53-Binding Protein 1