研究のタイプ: 医学/生物学の研究 (experimental study)

[高周波電磁界(GSM信号)は腫瘍抑制因子p53欠損した胚性幹細胞に影響を与える] med./bio.

High frequency electromagnetic fields (GSM signals) affect gene expression levels in tumor suppressor p53-deficient embryonic stem cells.

掲載誌: Bioelectromagnetics 2004; 25 (4): 296-307

この研究は、多分化能を有する胚性幹細胞(ES細胞)を用いて、GSM信号電磁界の影響を調べた。野生株ES細胞および腫瘍抑制因子p53欠損ES細胞に、パルス変調のGSM1800信号の種々のモードをガイドラインの限度値以下のレベルでばく露し、インビトロ分化中の遺伝子転写を解析した。その結果、GSM-217 では、p53欠損ES細胞で、熱ショックタンパクhsp70のmRNAレベルに上方調節がみられ、それと同時にc-jun、c-myc、p21レベルの一過性上昇が見られたが、野生株では変化が見られなかった;GSM-Talkでは、いずれの細胞株でも、何も影響が見られなかった、などを報告している。

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研究目的(著者による)

The effects of electromagnetic field exposure were comparatively analyzed in pluripotent embryonic stem cells and embryonic carcinoma cells, including embryonic stem cells deficient for p53, a tumor suppressor protein, to determine the cellular susceptibility to develop spontaneous tumors.

詳細情報

Two GSM modulation schemes (GSM-217 and GSM-Talk), which generate temporal changes between GSM-Basic (active during talking phases) and GSM-DTX (active during listening phases thus simulating a typical conversation), were applied to the cells.

影響評価項目

ばく露

ばく露 パラメータ
ばく露1: 1.71 GHz
Modulation type: pulsed
ばく露時間: intermittent, 5/30 min On/Off cycles for 6 or 48 hours
  • SAR: 1.5 W/kg average over time
  • SAR: 12 W/kg cf. remarks (slot SAR)
ばく露2: 1.71 GHz
Modulation type: pulsed
ばく露時間: intermittent, 5/30 min On/Off cycles for 72 hours
  • SAR: 2 W/kg average over time
  • SAR: 16 W/kg cf. remarks (slot SAR)
ばく露3: 1.71 GHz
Modulation type: pulsed
ばく露時間: intermittent, 5/30 min On/Off cycles for 22 or 40 hours
  • SAR: 2 W/kg average over time
  • SAR: 16 W/kg cf. remarks (slot SAR)
ばく露4: 1.71 GHz
Modulation type: pulsed
ばく露時間: intermittent, 5/30 min On/Off cycles for 6 or 48 hours
  • SAR: 0.4 W/kg average over time
  • SAR: 8 W/kg cf. remarks (slot SAR)

ばく露1

主たる特性
周波数 1.71 GHz
タイプ
  • electromagnetic field
特性
  • guided field
ばく露時間 intermittent, 5/30 min On/Off cycles for 6 or 48 hours
Modulation
Modulation type pulsed
Pulse width 0.576 ms
Duty cycle 12.5 %
Repetition frequency 217 Hz
Pulse type rectangular
Additional information

GSM-217 signals

ばく露装置
ばく露の発生源/構造
チャンバの詳細 Four R14 waveguides (two for EMF exposure and two for sham exposure) enclosed in an incubator (5% CO2, 37 °C) were used.
ばく露装置の詳細 Petri dishes (60 mm) were positioned in the H field maximum of a standing wave and exposed in E polarization.
Additional information Cells were EMF or sham exposed during differentiation in hanging drops.
パラメータ
測定量 種別 Method Mass 備考
SAR 1.5 W/kg average over time 測定値および計算値 - -
SAR 12 W/kg cf. remarks 測定値および計算値 - slot SAR

ばく露2

主たる特性
周波数 1.71 GHz
タイプ
  • electromagnetic field
特性
  • guided field
ばく露時間 intermittent, 5/30 min On/Off cycles for 72 hours
Modulation
Modulation type pulsed
Pulse width 0.576 ms
Duty cycle 12.5 %
Repetition frequency 217 Hz
Pulse type rectangular
Additional information

GSM-217 signals

ばく露装置
ばく露の発生源/構造
  • E1と同じ装置
Additional information Cells were EMF or sham exposed during cultivation in suspension.
パラメータ
測定量 種別 Method Mass 備考
SAR 2 W/kg average over time 測定値および計算値 - -
SAR 16 W/kg cf. remarks 測定値および計算値 - slot SAR

ばく露3

主たる特性
周波数 1.71 GHz
タイプ
  • electromagnetic field
特性
  • guided field
ばく露時間 intermittent, 5/30 min On/Off cycles for 22 or 40 hours
Modulation
Modulation type pulsed
Pulse width 0.576 ms
Duty cycle 12.5 %
Repetition frequency 217 Hz
Pulse type rectangular
Additional information

GSM-217 signals

ばく露装置
ばく露の発生源/構造
  • E1と同じ装置
Additional information Cells were EMF or sham exposed during cultivation in monolayer.
パラメータ
測定量 種別 Method Mass 備考
SAR 2 W/kg average over time 測定値および計算値 - -
SAR 16 W/kg cf. remarks 測定値および計算値 - slot SAR

ばく露4

主たる特性
周波数 1.71 GHz
タイプ
  • electromagnetic field
特性
  • guided field
ばく露時間 intermittent, 5/30 min On/Off cycles for 6 or 48 hours
Modulation
Modulation type pulsed
Pulse width 0.576 ms
Duty cycle 12.5 %
Repetition frequency 217 Hz
Pulse type rectangular
Additional information

GSM-Talk signals were applied consisting of 33% GSM-Basic and 67% GSM-DTX (discontinuous transmission mode). GSM-Basic is similar to GSM-217 signal , except that every 26th frame is idle. The frame structure of the DTX signal results in 2, 8 and 217 Hz components.

ばく露装置
ばく露の発生源/構造
  • E1と同じ装置
Additional information Cells were EMF or sham exposed during differentiation in hanging drops.
パラメータ
測定量 種別 Method Mass 備考
SAR 0.4 W/kg average over time 測定値および計算値 - -
SAR 8 W/kg cf. remarks 測定値および計算値 - slot SAR

Reference articles

ばく露を受けた生物:

方法 影響評価項目/測定パラメータ/方法

研究対象とした生物試料:
調査の時期:
  • ばく露後

研究の主なアウトカム(著者による)

GSM-217 electromagnetic fields (EMF) induced a significant upregulation of mRNA levels of the heat shock protein, hsp70 of p53-deficient embryonic stem cells differentiating in vitro, paralleled by a low and transient increase of c-jun, c-myc, and p21 levels in p53-deficient, but not in wild-type cells. No responses were revealed in either cell type after electromagnetic field exposure to GSM-Talk applied at similar slot-averaged specific absorption rates (SAR), but at lower time-averaged SAR values. Cardiac differentiation and cell cycle characteristics were not affected in embryonic stem and embryonic carcinoma cells after irradiation to GSM-217 EMF signals. The results indicate that the genetic background determines cellular responses to GSM modulated EMF.

研究の種別:

研究助成

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