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Note: This study found no significant biological effects under its experimental conditions. We include all studies for scientific completeness.

Cellular Effects

Effects of exposure to a 1950 MHz radio frequency field on expression of Hsp70 and Hsp27 in human glioma cells.

No Effects Found

Miyakoshi J, Takemasa K, Takashima Y, Ding GR, Hirose H, Koyama S · 2005

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RF radiation at cell phone-level exposures disrupted cellular protection mechanisms without triggering obvious stress responses in brain cells.

Plain English Summary

Summary written for general audiences

Researchers exposed human brain tumor cells to 1950 MHz radiofrequency radiation (similar to 3G cell phone frequencies) at various intensities for up to 2 hours. While the radiation didn't affect cell growth or activate major stress response proteins, it did reduce a specific cellular protection mechanism at the highest exposure level (10 W/kg). This suggests that even when cells appear unaffected, subtle molecular changes may still be occurring.

Why This Matters

This study reveals something important about how we evaluate EMF safety. The researchers found no obvious cellular damage or stress response activation, which industry advocates might cite as evidence of safety. But look deeper and you find that RF exposure actually impaired a key cellular protection mechanism - the phosphorylation of Hsp27, which helps cells respond to stress and maintain proper function. The exposure levels tested (1-10 W/kg SAR) span the range from typical cell phone use to the maximum allowed by safety standards. What this means for you is that even exposures that don't trigger obvious cellular alarms may still be interfering with your cells' ability to protect themselves. This is exactly why we need more research that looks beyond just whether cells die or grow abnormally - the subtle effects may be just as important for long-term health.

Exposure Details

SAR
1, 2, and 10 W/kg
Source/Device
1950 MHz
Exposure Duration
2h

Exposure Context

This study used 1, 2, and 10 W/kg for SAR (device absorption):

Building Biology guidelines are practitioner-based limits from real-world assessments. BioInitiative Report recommendations are based on peer-reviewed science. Check Your Exposure to compare your own measurements.

Where This Falls on the Concern Scale

Study Exposure Level in ContextStudy Exposure Level in ContextThis study: 1, 2, and 10 W/kgExtreme Concern - 0.1 W/kgFCC Limit - 1.6 W/kgEffects observed in the Extreme Concern range (Building Biology)FCC limit is 2 times higher than this level
A logarithmic frequency spectrum from 10 Hz to 100 GHz showing where this study's 1.95 GHz exposure sits relative to common EMF sources.Where This Frequency Sits on the EMF SpectrumELFVLFLF / MFHF / VHFUHFSHFmm10 Hz100 GHzThis study: 1.95 GHzPower lines50/60 Hz5G mm28 GHzLogarithmic scale

Study Details

To study the effects of exposure to a 1950 MHz radio frequency field on expression of Hsp70 and Hsp27 in human glioma cells.

Human glioma MO54 cells were used to investigate whether radio frequency (RF) field exposure could a...

It was found that sham exposed and RF exposed cells demonstrated a similar growth pattern up to 4 d...

Our results suggest that although exposure to a 1950 MHz RF field has no effect on cell proliferation and expression of Hsp 27 and Hsp70, it may inhibit the phosphorylation of Hsp27 at Serine 78 in MO54 cells.

Cite This Study
Miyakoshi J, Takemasa K, Takashima Y, Ding GR, Hirose H, Koyama S (2005). Effects of exposure to a 1950 MHz radio frequency field on expression of Hsp70 and Hsp27 in human glioma cells. Bioelectromagnetics. 26(4):251-257, 2005.
Show BibTeX
@article{j_2005_effects_of_exposure_to_3249,
  author = {Miyakoshi J and Takemasa K and Takashima Y and Ding GR and Hirose H and Koyama S},
  title = {Effects of exposure to a 1950 MHz radio frequency field on expression of Hsp70 and Hsp27 in human glioma cells.},
  year = {2005},
  
  url = {https://pubmed.ncbi.nlm.nih.gov/15832340/},
}
PubMed: 15832340

Cited By (71 papers)

View all 71 citing papers on Semantic Scholar

Quick Questions About This Study

A 2005 study found that 1950 MHz radiofrequency radiation (similar to 3G frequencies) did not affect the growth of human brain tumor cells over 4 days. Cells exposed to radiation showed similar growth patterns to unexposed cells, even at high exposure levels of 10 W/kg.
Research on 1950 MHz radiation showed no activation of major heat shock proteins Hsp27 and Hsp70 in human brain tumor cells. These proteins typically activate during cellular stress, suggesting the radiation didn't trigger significant stress responses at the tested exposure levels.
High-level 1950 MHz exposure at 10 W/kg significantly reduced phosphorylated Hsp27 levels in brain tumor cells. This molecular change occurred without affecting overall cell growth or stress protein expression, indicating subtle cellular effects even when cells appear normal.
A study exposing human brain tumor cells to 1950 MHz radiation for up to 2 hours found no effects on cell survival or growth. However, the highest exposure level (10 W/kg) did alter specific cellular protection mechanisms, suggesting potential molecular changes.
Research found that 1950 MHz radiation exposure didn't activate typical cellular stress indicators like Hsp70 and Hsp27 proteins in human glioma cells. However, it did reduce a specific cellular protection mechanism at high exposure levels, indicating subtle molecular effects.