Evaluation of the potential of mobile phone specific electromagnetic fields (UMTS) to produce micronuclei in human glioblastoma cell lines

Abstract

Evaluation of the potential of mobile phone specific electromagnetic fields (UMTS) to produce micronuclei in human glioblastoma cell lines Halh Al-Serori, Michael Kundi, Franziska Ferk, Miroslav Mišík,Armen Nersesyan, Manuel Murbach, Tamara T. Lah, Siegfried Knasmüller. Evaluation of the potential of mobile phone specific electromagnetic fields (UMTS) to produce micronuclei in human glioblastoma cell lines. Toxicology in Vitro. 40:264-271. April 2017. dx.doi.org Highlights • Aim was to find out if mobile phone specific radiation causes chromosomal damage. • The effect of the UMTS signal was tested in two human glioblastoma cell lines. • No induction of micronuclei and several other nuclear anomalies were found. • Induction of programmed cell death was observed in a p53 mutated cell line (U251). • In p53 proficient cells (U87) the apoptosis rate was not increased. Abstract Some epidemiological studies indicate that mobile phones cause glioblastomas in humans. Since it is known that genomic instability plays a key role in the etiology of cancer, we investigated the effects of the universal mobile telecommunications system radiofrequency (UMTS-RF) signal, which is used in "smart" phones, on micronucleus (MN) formation and other anomalies such as nuclear buds (NBUDs) and nucleoplasmatic bridges (NPBs). MN are formed by structural and numerical aberrations, NBs reflect gene amplification and NPBs are formed from dicentric chromosomes. The experiments were conducted with human glioblastoma cell lines, which differ in regard to their p53 status, namely U87 (wild-type) and U251 (mutated). The cells were cultivated for 16 h in presence and absence of fetal calf serum and exposed to different SAR doses (0.25, 0.50 and 1.00 W/kg), which reflect the exposure of humans, in presence and absence of mitomycin C as former studies indicate that RF may cause synergistic effects in combination with this drug. We found no evidence for induction of MN and other anomalies. However, with the highest dose, induction of apoptosis was observed in U251 cells on the basis of the morphological features of the cells. Our findings indicate that the UMTS-RF signal does not cause chromosomal damage in glioblastoma cells; the mechanisms which lead to induction of programmed cell death will be investigated in further studies. Excerpts 1950 MHz UMTS In conclusion, the results of the present study indicate that exposure of cultured human glioblastoma cells to mobile phone specific RF does not cause MN formation. These findings can be taken as an indication that mechanisms other than chromosomal damage lead to induction of glioblastomas, which was observed in a number of epidemiological studies (for review see IARC (2013) Volume 102). However, as described above we found clear evidence for induction of apoptosis in one of the cell lines with defective p53. The observation of induction of programmed cell death in a glioma derived cell line indicates that the UMTS signal causes physiological effects (such as primary DNA damage or other processes), which finally leads to the elimination of the cells. Future investigations will be conducted to understand the biological consequences and the molecular mechanisms which cause this phenomenon.

AI evidence extraction

Main findings

In U87 and U251 human glioblastoma cell lines exposed to a 1950 MHz UMTS-RF signal at SAR 0.25, 0.50, and 1.00 W/kg for 16 h, no evidence for induction of micronuclei or other nuclear anomalies (NBUDs, NPBs) was found. At the highest SAR dose, apoptosis was observed in the p53-mutated U251 cell line, while apoptosis was not increased in p53-proficient U87 cells.

Outcomes measured

• Micronucleus (MN) formation
• Nuclear buds (NBUDs)
• Nucleoplasmatic bridges (NPBs)
• Apoptosis / programmed cell death
• Other nuclear anomalies

Limitations

• Sample size not reported in the provided abstract/metadata
• In vitro cell-line model; generalizability to humans not established in the abstract
• Apoptosis assessment described as based on morphological features (details not provided in the abstract)
• Exposure parameters beyond frequency, SAR range, and 16 h cultivation/exposure conditions not fully detailed in the abstract

Suggested hubs

• mobile-phones-rf (0.9)
  Study tests a UMTS mobile-phone RF signal (1950 MHz) in cell lines.

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    "exposure": {
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        "source": "mobile phone (UMTS)",
        "frequency_mhz": 1950,
        "sar_wkg": 1,
        "duration": "16 h"
    },
    "population": "Human glioblastoma cell lines (U87 wild-type p53; U251 mutated p53)",
    "sample_size": null,
    "outcomes": [
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    ],
    "main_findings": "In U87 and U251 human glioblastoma cell lines exposed to a 1950 MHz UMTS-RF signal at SAR 0.25, 0.50, and 1.00 W/kg for 16 h, no evidence for induction of micronuclei or other nuclear anomalies (NBUDs, NPBs) was found. At the highest SAR dose, apoptosis was observed in the p53-mutated U251 cell line, while apoptosis was not increased in p53-proficient U87 cells.",
    "effect_direction": "mixed",
    "limitations": [
        "Sample size not reported in the provided abstract/metadata",
        "In vitro cell-line model; generalizability to humans not established in the abstract",
        "Apoptosis assessment described as based on morphological features (details not provided in the abstract)",
        "Exposure parameters beyond frequency, SAR range, and 16 h cultivation/exposure conditions not fully detailed in the abstract"
    ],
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    "confidence": 0.7399999999999999911182158029987476766109466552734375,
    "peer_reviewed_likely": "yes",
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        "SAR",
        "micronuclei",
        "genotoxicity",
        "glioblastoma",
        "U87",
        "U251",
        "p53",
        "apoptosis",
        "nuclear buds",
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