Low power microwave radiation inhibits the proliferation of rabbit lens epithelial cells by upregulating P27Kip1 expression.

Molecular vision · 2004 · Harm · Low evidence

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HarmLow evidencePaper 6418

Study snapshot

PublicationMolecular vision · 2004

Study typein_vitro

Reported directionHarm

Evidence ratingLow

Abstract

PURPOSE: The goal of this study was to examine the effects of low power microwave radiation (<10 mW/cm2) on the proliferation of cultured rabbit lens epithelial cells (RLEC). METHODS: Cultured RLEC were exposed to continuous microwave radiation at a frequency of 2,450 MHz and power densities of 0.10, 0.25, 0.50, 1.00, and 2.00 mW/cm2 for 8 h. Cell morphologic changes were observed under a phase-contrast microscope. Cell viability was measured using the MTT assay and cell cycle analysis was measured using flow cytometry. After exposure to 2.00 mW/cm2 microwave radiation for 4, 6, and 8 h, the expression of cell cycle-regulatory proteins, P21WAF1 and P27Kip1, was examined using western blot analysis. Finally, the levels of P21WAF1 and P27Kip1 mRNA were analyzed by reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: After 8 h of radiation treatment, cells treated with 0.50, 1.00, and 2.00 mW/cm2 microwave radiation exhibited decreased cell viability, increased cell condensation and an inhibition of DNA synthesis. RLEC showed significant G0/G1 arrest. No obvious changes could be detected in the 0.10 and 0.25 mW/cm2 microwave treatment groups. Protein expression of P27Kip1 was markedly increased after microwave radiation. However, the mRNA levels were unchanged. On the other hand, there were no detectable differences in P21WAF1 protein expression and mRNA levels between microwave treatment and control groups. CONCLUSIONS: This study suggests that low power microwave radiation higher than 0.50 mW/cm2 can inhibit lens epithelial cell proliferation, and increase the expression of P27Kip1. These effects may account for the decline of lens epithelial proliferation after exposure to microwave radiation.

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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 directionharm

PopulationCultured rabbit lens epithelial cells (RLEC)

Sample sizeNot supplied

Exposuremicrowave · 2450 MHz · Continuous exposure for 8 h (dose-response at 0.10–2.00 mW/cm2); additional time-course at 2.00 mW/cm2 for 4, 6, and 8 h

Evidence strengthLowConfidence: 78% · Peer reviewed: yes

Main findings

After 8 h exposure, 0.50, 1.00, and 2.00 mW/cm2 groups showed decreased cell viability, increased cell condensation, inhibition of DNA synthesis, and significant G0/G1 arrest; 0.10 and 0.25 mW/cm2 showed no obvious changes. P27Kip1 protein expression increased after microwave radiation while P27Kip1 mRNA was unchanged; P21WAF1 protein and mRNA showed no detectable differences versus controls.

Outcomes measured

Cell proliferation/viability (MTT)
Cell morphology (phase-contrast microscopy)
DNA synthesis inhibition
Cell cycle distribution (flow cytometry; G0/G1 arrest)
P27Kip1 protein expression (western blot)
P27Kip1 mRNA levels (RT-PCR)
P21WAF1 protein expression (western blot)
P21WAF1 mRNA levels (RT-PCR)

Limitations

In vitro cell culture model; relevance to in vivo exposure not addressed in abstract
Sample size and replication not reported in abstract
Thermal control/temperature monitoring not described in abstract
Only one frequency (2450 MHz) and limited exposure durations assessed

View raw extracted JSON

{
  "study_type": "in_vitro",
  "exposure": {
    "band": "microwave",
    "source": null,
    "frequency_mhz": 2450,
    "sar_wkg": null,
    "duration": "Continuous exposure for 8 h (dose-response at 0.10–2.00 mW/cm2); additional time-course at 2.00 mW/cm2 for 4, 6, and 8 h"
  },
  "population": "Cultured rabbit lens epithelial cells (RLEC)",
  "sample_size": null,
  "outcomes": [
    "Cell proliferation/viability (MTT)",
    "Cell morphology (phase-contrast microscopy)",
    "DNA synthesis inhibition",
    "Cell cycle distribution (flow cytometry; G0/G1 arrest)",
    "P27Kip1 protein expression (western blot)",
    "P27Kip1 mRNA levels (RT-PCR)",
    "P21WAF1 protein expression (western blot)",
    "P21WAF1 mRNA levels (RT-PCR)"
  ],
  "main_findings": "After 8 h exposure, 0.50, 1.00, and 2.00 mW/cm2 groups showed decreased cell viability, increased cell condensation, inhibition of DNA synthesis, and significant G0/G1 arrest; 0.10 and 0.25 mW/cm2 showed no obvious changes. P27Kip1 protein expression increased after microwave radiation while P27Kip1 mRNA was unchanged; P21WAF1 protein and mRNA showed no detectable differences versus controls.",
  "effect_direction": "harm",
  "limitations": [
    "In vitro cell culture model; relevance to in vivo exposure not addressed in abstract",
    "Sample size and replication not reported in abstract",
    "Thermal control/temperature monitoring not described in abstract",
    "Only one frequency (2450 MHz) and limited exposure durations assessed"
  ],
  "evidence_strength": "low",
  "confidence": 0.78,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "microwave radiation",
    "2450 MHz",
    "power density",
    "rabbit lens epithelial cells",
    "cell proliferation",
    "MTT",
    "cell cycle arrest",
    "G0/G1",
    "P27Kip1",
    "P21WAF1"
  ],
  "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: Not supplied
PubMed: 14990889

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