Power-line frequency electromagnetic fields do not induce changes in phosphorylation, localization, or expression of the 27-kilodalton heat shock protein in human keratinocytes.

Environmental health perspectives · 2003 · No effect · Low evidence

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No effectLow evidencePaper 5284

After exposure to 1 gauss (100 microT) 50–60 Hz EMF for 20 min to 24 hr, keratinocytes showed no change in HSP27 isoform pattern (no evidence of phosphorylation), no translocation of HSP27 to the nucleus, and no increase in HSP27 abundance. The study also rep…

Study snapshot

PublicationEnvironmental health perspectives · 2003

Study typein_vitro

Reported directionNo effect

Evidence ratingLow

Abstract

The linkage of the exposure to the power-line frequency (50-60 Hz) electromagnetic fields (EMF) with human cancers remains controversial after more than 10 years of study. The in vitro studies on the adverse effects of EMF on human cells have not yielded a clear conclusion. In this study, we investigated whether power-line frequency EMF could act as an environmental insult to invoke stress responses in human keratinocytes using the 27-kDa heat shock protein (HSP27) as a stress marker. After exposure to 1 gauss (100 micro T) EMF from 20 min to 24 hr, the isoform pattern of HSP27 in keratinocytes remained unchanged, suggesting that EMF did not induce the phosphorylation of this stress protein. EMF exposure also failed to induce the translocation of HSP27 from the cytoplasm to the nucleus. Moreover, EMF exposure did not increase the abundance of HSP27 in keratinocytes. In addition, we found no evidence that EMF exposure enhanced the level of the 70-kDa heat shock protein (HSP70) in breast or leukemia cells as reported previously. Therefore, in this study we did not detect any of a number of stress responses in human keratinocytes exposed to power-line frequency EMF.

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 directionno_effect

PopulationHuman keratinocytes (in vitro); also mentions breast or leukemia cells (in vitro) for HSP70 assessment

Sample sizeNot supplied

ExposureELF · 20 min to 24 hr

Evidence strengthLowConfidence: 78% · Peer reviewed: yes

Main findings

Outcomes measured

HSP27 phosphorylation (isoform pattern)
HSP27 subcellular localization/translocation (cytoplasm to nucleus)
HSP27 expression/abundance
HSP70 level in breast or leukemia cells

Limitations

Sample size not reported in abstract
In vitro design; findings may not generalize to in vivo human health outcomes
Only selected stress markers (HSP27/HSP70) and endpoints assessed

View raw extracted JSON

{
  "study_type": "in_vitro",
  "exposure": {
    "band": "ELF",
    "source": "power-line frequency",
    "frequency_mhz": null,
    "sar_wkg": null,
    "duration": "20 min to 24 hr"
  },
  "population": "Human keratinocytes (in vitro); also mentions breast or leukemia cells (in vitro) for HSP70 assessment",
  "sample_size": null,
  "outcomes": [
    "HSP27 phosphorylation (isoform pattern)",
    "HSP27 subcellular localization/translocation (cytoplasm to nucleus)",
    "HSP27 expression/abundance",
    "HSP70 level in breast or leukemia cells"
  ],
  "main_findings": "After exposure to 1 gauss (100 microT) 50–60 Hz EMF for 20 min to 24 hr, keratinocytes showed no change in HSP27 isoform pattern (no evidence of phosphorylation), no translocation of HSP27 to the nucleus, and no increase in HSP27 abundance. The study also reports no evidence that EMF exposure enhanced HSP70 levels in breast or leukemia cells.",
  "effect_direction": "no_effect",
  "limitations": [
    "Sample size not reported in abstract",
    "In vitro design; findings may not generalize to in vivo human health outcomes",
    "Only selected stress markers (HSP27/HSP70) and endpoints assessed"
  ],
  "evidence_strength": "low",
  "confidence": 0.78,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "power-line frequency",
    "50-60 Hz",
    "ELF EMF",
    "1 gauss",
    "100 microT",
    "human keratinocytes",
    "HSP27",
    "HSP70",
    "stress response",
    "phosphorylation",
    "translocation",
    "expression"
  ],
  "suggested_hubs": [
    {
      "slug": "occupational-exposure",
      "weight": 0.2,
      "reason": "Study examines power-line frequency (50–60 Hz) EMF, which is relevant to some occupational settings, though the work is in vitro."
    }
  ]
}

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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: 10.1289/ehp.5395
PubMed: 12611655

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