Nuclear translocation and DNA-binding activity of NFKB (NF-kappaB) after exposure of human monocytes to pulsed ultra-wideband electromagnetic fields (1 kV/cm) fails to transactivate kappaB-dependent gene expression.

Radiation research · 2006 · Mixed · Low evidence

← Research stream

MixedLow evidencePaper 5121

Study snapshot

PublicationRadiation research · 2006

Study typein_vitro

Reported directionMixed

Evidence ratingLow

Abstract

The objective of this study was to investigate whether exposure of human monocytes to a pulsed ultra-wideband electromagnetic field (EMF) of 1 kV/cm average peak power triggers a signaling pathway responsible for the transcriptional regulation of NFKB (NF-kappaB)-dependent gene expression. Human Mono Mac 6 (MM6) cells were exposed intermittently to EMF pulses for a total of 90 min. The pulse width was 0.79+/-0.01 ns and the pulse repetition rate was 250 pps. The temperature of the medium was maintained at 37 degrees C in both sham- and EMF-exposed flasks. Total NFKB DNA-binding activity was measured in the nuclear extracts by the electrophoretic mobility shift assay. Cells exposed to the EMFs and incubated for 24 h postexposure showed a 3.5+/-0.2-fold increase in the NFKB DNA-binding activity. Since activation of NFKB was observed, the possibility of kappaB-dependent gene expression in response to exposure to the EMFs was investigated using NFKB signal-specific gene arrays. The results revealed no difference in the NFKB-dependent gene expression profiles at 8 or 24 h postexposure, indicating that activated NFKB does not lead to the differential expression of kappaB-dependent target genes. To determine whether the absence of the kappaB-dependent gene expression was due to compromised transcriptional regulation of NFKB, the functional activity of NFKB was examined in cells transiently transfected with Mercury Pathway constructs containing 4x NFKB binding sites associated either with the luciferase reporter system or a control vector. Pulsed EMF exposure did not induce NFKB-driven luciferase activity in these cells, indicating that the activation of NFKB at 24 h after the 1 kV/cm EMF exposure is functionally inactive. From these results, it is clear that the EMF-induced NFKB activation is only a transient response, with minimal or no downstream effect.

Machine Enhanced Logic

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

PopulationHuman Mono Mac 6 (MM6) monocytes (cell line)

Sample sizeNot supplied

Exposureintermittent pulses for a total of 90 min; assessed at 8 h and 24 h postexposure

Evidence strengthLowConfidence: 78% · Peer reviewed: yes

Main findings

After intermittent exposure to pulsed ultra-wideband EMF (1 kV/cm) for 90 min, cells incubated 24 h postexposure showed a 3.5±0.2-fold increase in total NFKB DNA-binding activity. However, NFKB-dependent gene expression profiles showed no differences at 8 or 24 h postexposure, and pulsed EMF exposure did not induce NFKB-driven luciferase activity, suggesting the observed NFKB activation was functionally inactive with minimal or no downstream effect.

Outcomes measured

NFKB (NF-kappaB) nuclear translocation/DNA-binding activity (EMSA)
NFKB-dependent gene expression profiles (NFKB signal-specific gene arrays)
NFKB-driven luciferase reporter activity (4x NFKB binding sites)

Limitations

In vitro study using a single human monocyte cell line (MM6)
Sample size not reported in abstract
Exposure characterized by field strength and pulse parameters, but no frequency spectrum or SAR reported
Outcomes focused on NFKB pathway; may not capture other biological endpoints

View raw extracted JSON

{
  "study_type": "in_vitro",
  "exposure": {
    "band": null,
    "source": "pulsed ultra-wideband electromagnetic field",
    "frequency_mhz": null,
    "sar_wkg": null,
    "duration": "intermittent pulses for a total of 90 min; assessed at 8 h and 24 h postexposure"
  },
  "population": "Human Mono Mac 6 (MM6) monocytes (cell line)",
  "sample_size": null,
  "outcomes": [
    "NFKB (NF-kappaB) nuclear translocation/DNA-binding activity (EMSA)",
    "NFKB-dependent gene expression profiles (NFKB signal-specific gene arrays)",
    "NFKB-driven luciferase reporter activity (4x NFKB binding sites)"
  ],
  "main_findings": "After intermittent exposure to pulsed ultra-wideband EMF (1 kV/cm) for 90 min, cells incubated 24 h postexposure showed a 3.5±0.2-fold increase in total NFKB DNA-binding activity. However, NFKB-dependent gene expression profiles showed no differences at 8 or 24 h postexposure, and pulsed EMF exposure did not induce NFKB-driven luciferase activity, suggesting the observed NFKB activation was functionally inactive with minimal or no downstream effect.",
  "effect_direction": "mixed",
  "limitations": [
    "In vitro study using a single human monocyte cell line (MM6)",
    "Sample size not reported in abstract",
    "Exposure characterized by field strength and pulse parameters, but no frequency spectrum or SAR reported",
    "Outcomes focused on NFKB pathway; may not capture other biological endpoints"
  ],
  "evidence_strength": "low",
  "confidence": 0.78,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "ultra-wideband",
    "pulsed EMF",
    "1 kV/cm",
    "human monocytes",
    "MM6",
    "NF-kappaB",
    "NFKB",
    "DNA-binding activity",
    "gene expression array",
    "luciferase reporter"
  ],
  "suggested_hubs": []
}

AI can be wrong. Always verify against the paper.

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: 10.1667/rr3564.1
PubMed: 16802864

Read the original paper →

Related papers

← Back to the Research Library