900 MHz modulated electromagnetic fields accelerate the clathrin-mediated endocytosis pathway.

Bioelectromagnetics · 2009 · Mixed · Low evidence

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MixedLow evidencePaper 4977

Study snapshot

PublicationBioelectromagnetics · 2009

Study typein_vitro

Reported directionMixed

Evidence ratingLow

Abstract

We report new data regarding the molecular mechanisms of GSM-induced increase of cell endocytosis rate. Even though endocytosis represents an important physical and biological event for cell physiology, studies on modulated electromagnetic fields (EMF) effects on this process are scarce. In a previous article, we showed that fluid phase endocytosis rate increases when cultured cells are exposed to 900 MHz EMF similar to mobile phones' modulated GSM signals (217 Hz repetition frequency, 576 micros pulse width) and to electric pulses similar to the GSM electrical component. Trying to distinguish the mechanisms sustaining this endocytosis stimulation, we exposed murine melanoma cells to Lucifer Yellow (LY) or to GSM-EMF/electric pulses in the presence of drugs inhibiting the clathrin- or the caveolin-dependent endocytosis. Experiments were performed at a specific absorption rate (SAR) of 3.2 W/kg in a wire patch cell under homogeneously distributed EMF field and controlled temperature (in the range of 28.5-29.5 degrees C). Thus, the observed increase in LY uptake was not a thermal effect. Chlorpromazine and ethanol, but not Filipin, inhibited this increase. Therefore, the clathrin-dependent endocytosis is stimulated by the GSM-EMF, suggesting that the cellular mechanism affected by the modulated EMF involves vesicles that detach from the cell membrane, mainly clathrin-coated vesicles.

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AI evidence extraction

Structured fields below were generated from the paper’s abstract and metadata to make the evidence easier to inspect. Automated extraction may be incomplete or incorrect; verify important details against the original paper.

Study typein_vitro

Effect directionmixed

PopulationMurine melanoma cells (cultured)

Sample sizeNot supplied

ExposureRF · 900 MHz · 3.2 W/kg

Evidence strengthLowConfidence: 78% · Peer reviewed: yes

Main findings

Murine melanoma cells exposed to 900 MHz GSM-like modulated EMF (and GSM-like electric pulses) showed increased Lucifer Yellow uptake (fluid phase endocytosis). The increase was inhibited by chlorpromazine and ethanol (clathrin-pathway inhibitors) but not by Filipin (caveolin-pathway inhibitor), suggesting stimulation of clathrin-dependent endocytosis; temperature was controlled and authors state the effect was not thermal.

Outcomes measured

Cell endocytosis rate
Fluid phase endocytosis (Lucifer Yellow uptake)
Clathrin-mediated endocytosis vs caveolin-dependent endocytosis (drug inhibition tests)

Limitations

In vitro cell model (murine melanoma cells), limiting generalizability to humans or in vivo conditions
Exposure duration not stated in the abstract
Sample size and number of replicates not reported in the abstract
Mechanistic inference based on pharmacological inhibitors; specificity of inhibitors not discussed in the abstract

View raw extracted JSON

{
  "study_type": "in_vitro",
  "exposure": {
    "band": "RF",
    "source": "mobile phone",
    "frequency_mhz": 900,
    "sar_wkg": 3.2,
    "duration": null
  },
  "population": "Murine melanoma cells (cultured)",
  "sample_size": null,
  "outcomes": [
    "Cell endocytosis rate",
    "Fluid phase endocytosis (Lucifer Yellow uptake)",
    "Clathrin-mediated endocytosis vs caveolin-dependent endocytosis (drug inhibition tests)"
  ],
  "main_findings": "Murine melanoma cells exposed to 900 MHz GSM-like modulated EMF (and GSM-like electric pulses) showed increased Lucifer Yellow uptake (fluid phase endocytosis). The increase was inhibited by chlorpromazine and ethanol (clathrin-pathway inhibitors) but not by Filipin (caveolin-pathway inhibitor), suggesting stimulation of clathrin-dependent endocytosis; temperature was controlled and authors state the effect was not thermal.",
  "effect_direction": "mixed",
  "limitations": [
    "In vitro cell model (murine melanoma cells), limiting generalizability to humans or in vivo conditions",
    "Exposure duration not stated in the abstract",
    "Sample size and number of replicates not reported in the abstract",
    "Mechanistic inference based on pharmacological inhibitors; specificity of inhibitors not discussed in the abstract"
  ],
  "evidence_strength": "low",
  "confidence": 0.78,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "900 MHz",
    "GSM",
    "modulated electromagnetic fields",
    "RF-EMF",
    "specific absorption rate",
    "SAR 3.2 W/kg",
    "endocytosis",
    "Lucifer Yellow uptake",
    "clathrin-mediated endocytosis",
    "caveolin",
    "chlorpromazine",
    "Filipin",
    "murine melanoma cells"
  ],
  "suggested_hubs": [
    {
      "slug": "mobile-phones-rf",
      "weight": 0.9,
      "reason": "Uses 900 MHz GSM-like modulated signals similar to mobile phones and reports cellular effects."
    }
  ]
}

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AI-extracted fields are generated from the abstract and metadata and may be incomplete or incorrect. This material is for informational purposes and is not medical advice.

Identifiers and source

DOI: 10.1002/bem.20463
PubMed: 19072782

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