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Effects of 1800 MHz radiofrequency fields on signal transduction and antioxidant proteins in human A172 glioblastoma cells.

International journal of radiation biology · 2021 · No effect · Low evidence

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No effectLow evidencePaper 5691

Some statistically significant decreases were observed for specific proteins under particular conditions (e.g., CAT, total JNK, STAT3, phosphorylated-CREB with continuous-wave exposure in serum; total STAT5 with GSM-modulated exposure in serum-free cultures),…

Study snapshot

PublicationInternational journal of radiation biology · 2021
Study typein_vitro
Reported directionNo effect
Evidence ratingLow

Abstract

PURPOSE: To assess the effects of 1800 MHz radiofrequency electromagnetic field (RF-EMF) exposure on the expression of signal transduction and antioxidant proteins in a human-derived A172 glioblastoma cell line. MATERIALS AND METHODS: Adherent human-derived A172 glioblastoma cells (1.0 × 10 cells per 35 mm culture dish, containing 2 mL DMEM media) were exposed to 1800 MHz continuous-wave (CW) or GSM-modulated RF fields, in the presence or absence of serum for 5, 30 or 240 min at a specific absorption rate (SAR) of 0 (sham) or 2.0 W/kg. Concurrent negative (vehicle) and positive controls (1 µg/mL anisomycin) were included in each experiment. Cell lysates were collected immediately after exposure, stabilized by protease and phosphatase inhibitors in lysis buffer, then frozen and maintained at -80 °C until analysis. The relative expression levels of phosphorylated- and total-signal transduction proteins (CREB, JNK, NF-κB, ERK1/2, Akt, p70S6K, STAT3 and STAT5) and antioxidant proteins (SOD1, SOD2, CAT, TRX1, PRX2) were assessed using Milliplex magnetic bead array panels and a MagPix Multiplex imaging system. RESULTS: In cells exposed to 1800 MHz continuous-wave RF-EMF with the presence of serum in the culture medium, CAT expression was statistically significantly decreased after a 30 min exposure, total JNK was decreased at both 30 and 240 min of exposure, STAT3 was decreased after 240 min of exposure and phosphorylated-CREB expression was decreased after 30 min of exposure. In cells exposed to 1800 MHz GSM-modulated RF-EMF in serum-free cultures, the expression level of total STAT5 was decreased after 30 and 240 min of exposure. These observed changes were detected sporadically across time-points, culture conditions and RF-EMF exposure conditions indicating the likelihood of false positive events. When cells were treated with anisomycin for 15 min as a positive control, dramatic increases in the expression of phosphorylated signaling proteins were observed in both serum-starved and serum-fed A172 cells, with larger fold change increases in the serum-free cultures. No statistically significant differences in the expression levels of SOD1, SOD2 or TRX1 were observed under any tested conditions after exposure to RF-EMF. CONCLUSIONS: The current study found no consistent evidence of changes in the expression of antioxidant proteins (SOD1, SOD2, CAT or TRX2) or a variety of signal transductions proteins (CREB, JNK, NF-κB, ERK1/2, Akt, p70S6K, STAT3, STAT5) in a human-derived glioblastoma A172 cell line in response to exposure to 1800 MHz continuous-wave or GSM-modulated RF-EMF for 5, 30 or 240 min in either serum-free or serum-containing cultures.

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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 directionno_effect
PopulationHuman-derived A172 glioblastoma cell line (adherent cells)
Sample sizeNot supplied
ExposureRF · 1800 MHz · 2 W/kg · 5, 30 or 240 min
Evidence strengthLowConfidence: 78% · Peer reviewed: yes

Main findings

Some statistically significant decreases were observed for specific proteins under particular conditions (e.g., CAT, total JNK, STAT3, phosphorylated-CREB with continuous-wave exposure in serum; total STAT5 with GSM-modulated exposure in serum-free cultures), but these changes were sporadic across time points and conditions and were interpreted as likely false positives. Overall, the study concluded there was no consistent evidence of RF-EMF-induced changes in the assessed antioxidant or signal transduction proteins after 1800 MHz continuous-wave or GSM-modulated exposure for 5–240 minutes at 2.0 W/kg.

Outcomes measured

  • Expression levels of signal transduction proteins (phosphorylated and total: CREB, JNK, NF-κB, ERK1/2, Akt, p70S6K, STAT3, STAT5)
  • Expression levels of antioxidant proteins (SOD1, SOD2, CAT, TRX1, PRX2)

Limitations

  • Sample size/number of replicates not reported in abstract
  • Multiple proteins and conditions tested with sporadic significant findings noted as likely false positives
  • In vitro cell-line model (A172 glioblastoma) may not generalize beyond this system
  • Only immediate post-exposure measurements reported in abstract
View raw extracted JSON
{
  "study_type": "in_vitro",
  "exposure": {
    "band": "RF",
    "source": null,
    "frequency_mhz": 1800,
    "sar_wkg": 2,
    "duration": "5, 30 or 240 min"
  },
  "population": "Human-derived A172 glioblastoma cell line (adherent cells)",
  "sample_size": null,
  "outcomes": [
    "Expression levels of signal transduction proteins (phosphorylated and total: CREB, JNK, NF-κB, ERK1/2, Akt, p70S6K, STAT3, STAT5)",
    "Expression levels of antioxidant proteins (SOD1, SOD2, CAT, TRX1, PRX2)"
  ],
  "main_findings": "Some statistically significant decreases were observed for specific proteins under particular conditions (e.g., CAT, total JNK, STAT3, phosphorylated-CREB with continuous-wave exposure in serum; total STAT5 with GSM-modulated exposure in serum-free cultures), but these changes were sporadic across time points and conditions and were interpreted as likely false positives. Overall, the study concluded there was no consistent evidence of RF-EMF-induced changes in the assessed antioxidant or signal transduction proteins after 1800 MHz continuous-wave or GSM-modulated exposure for 5–240 minutes at 2.0 W/kg.",
  "effect_direction": "no_effect",
  "limitations": [
    "Sample size/number of replicates not reported in abstract",
    "Multiple proteins and conditions tested with sporadic significant findings noted as likely false positives",
    "In vitro cell-line model (A172 glioblastoma) may not generalize beyond this system",
    "Only immediate post-exposure measurements reported in abstract"
  ],
  "evidence_strength": "low",
  "confidence": 0.78,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "1800 MHz",
    "RF-EMF",
    "GSM-modulated",
    "continuous-wave",
    "SAR 2.0 W/kg",
    "A172",
    "glioblastoma cells",
    "signal transduction",
    "antioxidant proteins",
    "CREB",
    "JNK",
    "NF-κB",
    "ERK1/2",
    "Akt",
    "STAT3",
    "STAT5",
    "SOD1",
    "SOD2",
    "CAT",
    "TRX1",
    "PRX2"
  ],
  "suggested_hubs": []
}
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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: 10.1080/09553002.2021.1934751
PubMed: 34047676

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