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

著者: Czyz J, Guan K, Zeng Q, Nikolova T, Meister A, Schönborn F, Schuderer J, Kuster N, Wobus AM
掲載誌: Bioelectromagnetics 2004; 25 (4): 296-307
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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、インビトロで分化中の遺伝子の転写を解析した。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 値 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
Additional parameter details

SAR values have been determined with simulations and measurements and represent voxel average values over the area of the cells. The uncertainty for the average values was assessed to be ±50% for hanging drops and ±20% for suspension cultivation.

測定および計算の詳細

The entire setup was computer controlled, enabling the automated setting of the modulation scheme as well as the exposure strength for the different media and culture applications.

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 値 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 値 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 値 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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