Radiofrequency radiation (900 MHz) induces Egr-1 gene expression and affects cell-cycle control in human neuroblastoma cells.

Abstract

Many environmental signals, including ionizing radiation and UV rays, induce activation of Egr-1 gene, thus affecting cell growth and apoptosis. The paucity and the controversial knowledge about the effect of electromagnetic fields (EMF) exposure of nerve cells prompted us to investigate the bioeffects of radiofrequency (RF) radiation on SH-SY5Y neuroblastoma cells. The effect of a modulated RF field of 900 MHz, generated by a wire patch cell (WPC) antenna exposure system on Egr-1 gene expression, was studied as a function of time. Short-term exposures induced a transient increase in Egr-1 mRNA level paralleled with activation of the MAPK subtypes ERK1/2 and SAPK/JNK. The effects of RF radiations on cell growth rate and apoptosis were also studied. Exposure to RF radiation had an anti-proliferative activity in SH-SY5Y cells with a significant effect observed at 24 h. RF radiation impaired cell cycle progression, reaching a significant G2-M arrest. In addition, the appearance of the sub-G1 peak, a hallmark of apoptosis, was highlighted after a 24-h exposure, together with a significant decrease in mRNA levels of Bcl-2 and survivin genes, both interfering with signaling between G2-M arrest and apoptosis. Our results provide evidence that exposure to a 900 MHz-modulated RF radiation affect both Egr-1 gene expression and cell regulatory functions, involving apoptosis inhibitors like Bcl-2 and survivin, thus providing important insights into a potentially broad mechanism for controlling in vitro cell viability.

AI evidence extraction

Main findings

In SH-SY5Y human neuroblastoma cells, short-term 900 MHz modulated RF exposure induced a transient increase in Egr-1 mRNA, paralleling activation of ERK1/2 and SAPK/JNK. RF exposure showed anti-proliferative activity with a significant effect at 24 h, impaired cell-cycle progression with significant G2-M arrest, and was associated with a sub-G1 peak after 24 h along with decreased Bcl-2 and survivin mRNA levels.

Outcomes measured

• Egr-1 mRNA expression
• MAPK activation (ERK1/2, SAPK/JNK)
• cell growth rate / proliferation
• cell-cycle progression (G2-M arrest)
• apoptosis (sub-G1 peak)
• Bcl-2 mRNA levels
• survivin mRNA levels

Limitations

• No SAR or exposure intensity reported in the abstract
• In vitro neuroblastoma cell model; generalizability to in vivo/humans not addressed in abstract
• Sample size and replication details not provided in abstract

{
    "study_type": "in_vitro",
    "exposure": {
        "band": "RF",
        "source": "antenna exposure system (wire patch cell (WPC) antenna)",
        "frequency_mhz": 900,
        "sar_wkg": null,
        "duration": "short-term exposures (time course) and 24 h exposure"
    },
    "population": null,
    "sample_size": null,
    "outcomes": [
        "Egr-1 mRNA expression",
        "MAPK activation (ERK1/2, SAPK/JNK)",
        "cell growth rate / proliferation",
        "cell-cycle progression (G2-M arrest)",
        "apoptosis (sub-G1 peak)",
        "Bcl-2 mRNA levels",
        "survivin mRNA levels"
    ],
    "main_findings": "In SH-SY5Y human neuroblastoma cells, short-term 900 MHz modulated RF exposure induced a transient increase in Egr-1 mRNA, paralleling activation of ERK1/2 and SAPK/JNK. RF exposure showed anti-proliferative activity with a significant effect at 24 h, impaired cell-cycle progression with significant G2-M arrest, and was associated with a sub-G1 peak after 24 h along with decreased Bcl-2 and survivin mRNA levels.",
    "effect_direction": "harm",
    "limitations": [
        "No SAR or exposure intensity reported in the abstract",
        "In vitro neuroblastoma cell model; generalizability to in vivo/humans not addressed in abstract",
        "Sample size and replication details not provided in abstract"
    ],
    "evidence_strength": "low",
    "confidence": 0.7399999999999999911182158029987476766109466552734375,
    "peer_reviewed_likely": "yes",
    "keywords": [
        "radiofrequency",
        "900 MHz",
        "modulated RF",
        "SH-SY5Y",
        "neuroblastoma",
        "Egr-1",
        "MAPK",
        "ERK1/2",
        "SAPK/JNK",
        "cell cycle",
        "G2-M arrest",
        "apoptosis",
        "Bcl-2",
        "survivin"
    ],
    "suggested_hubs": []
}

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