Microwaves from Mobile Phones Inhibit 53BP1 Focus Formation in Human Stem Cells More Strongly Than in Differentiated Cells: Possible Mechanistic Link to Cancer Risk.

Background: It is widely accepted that DNA double-strand breaks (DSBs) and their misrepair instem cells are critical events in the multistage origination of various leukemias and tumors, includinggliomas.Objectives: We studied whether microwaves from mobile telephones of the Global System forMobile Communication (GSM) and the Universal Global Telecommunications System (UMTS)induce DSBs or affect DSB repair in stem cells.Methods: We analyzed tumor suppressor TP53 binding protein 1 (53BP1) foci that are typicallyformed at the sites of DSB location (referred to as DNA repair foci) by laser confocal microscopy.Results: Microwaves from mobile phones inhibited formation of 53BP1 foci in human primaryfibroblasts and mesenchymal stem cells. These data parallel our previous findings for humanlymphocytes.Importantly, the same GSM carrier frequency (915 MHz) and UMTS frequency band(1947.4 MHz) were effective for all cell types. Exposure at 905 MHz did not inhibit 53BP1 foci indifferentiated cells, either fibroblasts or lymphocytes, whereas some effects were seen in stem cells at905 MHz. Contrary to fibroblasts, stem cells did not adapt to chronic exposure during 2 weeks.Conclusions: The strongest microwave effects were always observed in stem cells. This result maysuggest both significant misbalance in DSB repair and severe stress response. Our findings that stemcells are most sensitive to microwave exposure and react to more frequencies than do differentiatedcells may be important for cancer risk assessment and indicate that stem cells are the most relevantcellular model for validating safe mobile communication signals. [ABSTRACT FROM AUTHOR]

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