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Updated: Jun 30, 2026
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Published on: March 29, 2019
Pre-exposure to 50 Hz magnetic fields modifies menadione-induced DNA damage response in murine L929 cells
Ari Markkanen1, Jukka Juutilainen, Jonne Naarala
1Department of Environmental Science, University of Kuopio, Kuopio, Finland. ari.markkanen@ktl.fi
Purpose:
Effects on DNA damage response were investigated in murine L929 cells exposed to 50 Hz magnetic fields (MF) with or without ultraviolet B (UVB, wavelength 280-320 nm) radiation or menadione (MQ).
Materials And Methods:
Cells were exposed to MF at 100 or 300 microT combined with MQ (150 microM, 1 hour) or UVB radiation (160 J/m(2)) using various exposure schedules. The samples were stained with propidium iodide (PI) and analysed by flow cytometer for cell cycle stages. Apoptotic cells were defined as sub G(1) events.
Results:
In cells first exposed to 100 microT MF for 24 h, the response to subsequent MQ treatment was significantly altered so that the proportion of sub G(1) cells was decreased and the proportion of cells in the G(2)/M phase was increased. When a 300 microT MF was used, also the proportion of cells in the G(1) phase was decreased. MF exposures after MQ treatment did not alter responses to MQ. No effects were found from MF exposure alone or from MF combined with UVB radiation.
Conclusions:
The results strengthen previous findings suggesting that pre-exposure to MF can alter cellular responses to other agents, and indicate that MF as low as 100 microT has measurable impacts on cancer-relevant cellular processes such as DNA-damage.
Insights
Pre-exposure to magnetic fields (MF) alters cellular responses to DNA damage agents. Even low levels of MF (100 microT) impact cancer-relevant processes, affecting cell cycle progression and apoptosis.
Area of Science:
- Cellular and Molecular Biology
- Biophysics
- Environmental Health
Background:
- Investigating cellular responses to environmental stressors is crucial for understanding health impacts.
- DNA damage response pathways are key targets in cancer research.
- Electromagnetic fields (EMF) are ubiquitous, necessitating research into their biological effects.
Purpose of the Study:
- To investigate the effects of 50 Hz magnetic fields (MF) on DNA damage response in murine L929 cells.
- To determine if MF exposure modifies cellular responses when combined with ultraviolet B (UVB) radiation or menadione (MQ).
Main Methods:
- Murine L929 cells were exposed to MF (100 or 300 microT) with or without UVB or MQ.
- Cell cycle analysis was performed using propidium iodide staining and flow cytometry.
- Apoptotic cells were quantified as sub G(1) events.
Main Results:
- Pre-exposure to 100 microT MF for 24 hours significantly decreased apoptosis (sub G(1)) and increased G(2)/M phase cells following MQ treatment.
- Higher MF intensity (300 microT) also decreased G(1) phase cells.
- MF exposure after MQ treatment or in combination with UVB did not alter cellular responses.
Conclusions:
- Pre-exposure to MF can modulate cellular responses to genotoxic agents.
- Magnetic fields as low as 100 microT demonstrate measurable impacts on DNA damage response and cell cycle regulation.
- These findings highlight MF's potential role in cancer-relevant cellular processes.
