Gene expression in human breast epithelial cells exposed to 60 Hz magnetic fields.

Carcinogenesis · 1999 · No effect · Low evidence

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No effectLow evidencePaper 5369

Study snapshot

PublicationCarcinogenesis · 1999

Study typein_vitro

Reported directionNo effect

Evidence ratingLow

Abstract

Epidemiology suggests a possible relationship between exposure to power frequency magnetic fields (EMF) and breast cancer. One mechanism through which EMF could stimulate breast cancer induction is via altered expression of oncogenes and/or tumor suppressor genes that regulate normal and neoplastic growth. To evaluate the hypothesis that EMF action in the breast is mediated by alterations in gene expression, transcript levels of c-myc and a battery of other cancer-associated genes were quantitated in human breast epithelial cells exposed to pure, linearly polarized 60 Hz EMF with low harmonic distortion. HBL-100 cells and normal (non-transformed) human mammary epithelial cells were exposed to EMF flux densities of 0.1, 1.0 and 10.0 Gauss (G) for periods ranging from 20 min to 24 h; concurrent sham controls were exposed to ambient fields (<0.001 G) only. Gene expression was quantitated using ribonuclease protection assays. EMF exposure had no statistically significant effect on basal levels of c-myc transcripts in either human breast cell model, and had no effect on alterations in c-myc expression induced by 12-O-tetradecanoylphorbol-13-acetate. Transcript levels of c-erbB-2, p53, p21, GADD45, bax, bcl-x, mcl-1, and c-fos were also unaffected by EMF exposure. These results suggest that EMF is unlikely to influence breast cancer induction through a mechanism involving altered expression of these genes.

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 breast epithelial cells (HBL-100 and normal/non-transformed human mammary epithelial cells)

Sample sizeNot supplied

ExposureELF · 6e-05 MHz · 20 min to 24 h

Evidence strengthLowConfidence: 78% · Peer reviewed: yes

Main findings

Human breast epithelial cells exposed to pure, linearly polarized 60 Hz magnetic fields at 0.1, 1.0, or 10.0 G for 20 min to 24 h showed no statistically significant changes in basal c-myc transcript levels versus sham controls (<0.001 G). EMF exposure also did not affect 12-O-tetradecanoylphorbol-13-acetate-induced changes in c-myc, and transcript levels of several other cancer-associated genes (c-erbB-2, p53, p21, GADD45, bax, bcl-x, mcl-1, c-fos) were unaffected.

Outcomes measured

Transcript levels / gene expression of c-myc
Transcript levels / gene expression of c-erbB-2
Transcript levels / gene expression of p53
Transcript levels / gene expression of p21
Transcript levels / gene expression of GADD45
Transcript levels / gene expression of bax
Transcript levels / gene expression of bcl-x
Transcript levels / gene expression of mcl-1
Transcript levels / gene expression of c-fos
Effect of EMF on 12-O-tetradecanoylphorbol-13-acetate-induced alterations in c-myc expression

View raw extracted JSON

{
  "study_type": "in_vitro",
  "exposure": {
    "band": "ELF",
    "source": null,
    "frequency_mhz": 6e-05,
    "sar_wkg": null,
    "duration": "20 min to 24 h"
  },
  "population": "Human breast epithelial cells (HBL-100 and normal/non-transformed human mammary epithelial cells)",
  "sample_size": null,
  "outcomes": [
    "Transcript levels / gene expression of c-myc",
    "Transcript levels / gene expression of c-erbB-2",
    "Transcript levels / gene expression of p53",
    "Transcript levels / gene expression of p21",
    "Transcript levels / gene expression of GADD45",
    "Transcript levels / gene expression of bax",
    "Transcript levels / gene expression of bcl-x",
    "Transcript levels / gene expression of mcl-1",
    "Transcript levels / gene expression of c-fos",
    "Effect of EMF on 12-O-tetradecanoylphorbol-13-acetate-induced alterations in c-myc expression"
  ],
  "main_findings": "Human breast epithelial cells exposed to pure, linearly polarized 60 Hz magnetic fields at 0.1, 1.0, or 10.0 G for 20 min to 24 h showed no statistically significant changes in basal c-myc transcript levels versus sham controls (<0.001 G). EMF exposure also did not affect 12-O-tetradecanoylphorbol-13-acetate-induced changes in c-myc, and transcript levels of several other cancer-associated genes (c-erbB-2, p53, p21, GADD45, bax, bcl-x, mcl-1, c-fos) were unaffected.",
  "effect_direction": "no_effect",
  "limitations": [],
  "evidence_strength": "low",
  "confidence": 0.78,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "60 Hz",
    "power frequency",
    "magnetic fields",
    "ELF-EMF",
    "breast epithelial cells",
    "HBL-100",
    "mammary epithelial cells",
    "gene expression",
    "c-myc",
    "oncogenes",
    "tumor suppressor genes",
    "ribonuclease protection assay",
    "sham control",
    "Gauss"
  ],
  "suggested_hubs": [
    {
      "slug": "occupational-exposure",
      "weight": 0.25,
      "reason": "Study examines power-frequency (60 Hz) magnetic-field exposure relevant to power/occupational environments, though conducted 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: 10.1093/carcin/20.8.1633
PubMed: 10426819

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