Medical/biological study (experimental study)

The influence of 1.2 microT, 60 Hz magnetic fields on melatonin- and tamoxifen-induced inhibition of MCF-7 cell growth.

Published in: Bioelectromagnetics 2001; 22 (2): 122-128

Aim of study (acc. to author)

To replicate the study of Harland and Liburdy (1997), in which the exposure to 60 Hz magnetic fields could significantly reduce the inhibitory action of melatonin and tamoxifen on the growth of MCF-7 human breast cancer cells in vitro.
Background/further details: In the melatonin study, nine cell samples were subdivided in the following groups and investigated on day 7: 1.) control group, 2.) melatonin group (10 -9 M), and 3.) melatonin + exposure group.
In the tamoxifen study, 48 cell samples were subdivided in the following groups: 1.) control group, 2.) tamoxifen group (10 -7 M), and 3.) tamoxifen + exposure group. The samples were investigated on days 4, 5, 6, and 7.



Exposure Parameters
Exposure 1: 60 Hz
Exposure duration: continuous, up to 7 days
Exposure 1
Main characteristics
Frequency 60 Hz
Exposure duration continuous, up to 7 days
Exposure setup
Exposure source
Chamber CO2 incubator, 35 mm dishes
Setup coils with 1000 turns, 20 cm diameter, 10 cm apart, vertical field; culture dishes in uniform field region
Sham exposure A sham exposure was conducted.
Measurand Value Type Method Mass Remarks
magnetic flux density 1.2 µT effective value measured - -
Additional parameter details
ambient fields: 0.04 µT rms; static magnetic field < 0.3 µT
Reference articles
Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated material:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

In the melatonin study, cell numbers were significantly reduced (by 16.7%) in the melatonin treated cultures after 7 days of incubation compared to control cultures, whereas the melatonin treated and exposed cultures had the same cell populations as the control cultures. In the tamoxifen study, tamoxifen reduced the cell growth by 18.6% and 25% on days 6 and 7, respectively, compared to the control group, while the cell growth in the tamoxifen treated and exposed cell cultures was reduced only by 8.7% and 13.1%, respectively.
The authors conclude that these results are consistent with those reported by Harland and Liburdy (1997).
Study character:

Study funded by

  • Department of Energy, USA

Related articles

  • Lee HC et al. (2015): Effect of extremely low frequency magnetic fields on cell proliferation and gene expression.
  • Kakikawa M et al. (2014): Effect of Extremely Low-Frequency (ELF) Magnetic Fields on the Potency of Drugs in Bacterial Cells.
  • Trillo MA et al. (2013): Retinoic acid inhibits the cytoproliferative response to weak 50Hz magnetic fields in neuroblastoma cells.
  • Trillo MA et al. (2012): Influence of a 50 Hz magnetic field and of all-transretinol on the proliferation of human cancer cell lines.
  • Cid MA et al. (2012): Antagonistic effects of a 50 Hz magnetic field and melatonin in the proliferation and differentiation of hepatocarcinoma cells.
  • Kakikawa M et al. (2012): Effect of Extremely Low-Frequency (ELF) Magnetic Fields on Anticancer Drugs Potency.
  • Girgert R et al. (2010): Signal transduction of the melatonin receptor MT1 is disrupted in breast cancer cells by electromagnetic fields.
  • Girgert R et al. (2008): Electromagnetic fields alter the expression of estrogen receptor cofactors in breast cancer cells.
  • Girgert R et al. (2005): Induction of tamoxifen resistance in breast cancer cells by ELF electromagnetic fields.
  • Zwirska-Korczala K et al. (2004): Influence of extremely-low-frequency magnetic field on antioxidative melatonin properties in AT478 murine squamous cell carcinoma culture.
  • Leman ES et al. (2001): Studies of the interactions between melatonin and 2 Hz, 0.3 mT PEMF on the proliferation and invasion of human breast cancer cells.
  • Ishido M et al. (2001): Magnetic fields (MF) of 50 Hz at 1.2 microT as well as 100 microT cause uncoupling of inhibitory pathways of adenylyl cyclase mediated by melatonin 1a receptor in MF-sensitive MCF-7 cells.
  • Jajte J et al. (2001): Protective effect of melatonin against in vitro iron ions and 7 mT 50 Hz magnetic field-induced DNA damage in rat lymphocytes.
  • Harland J et al. (1999): Evidence for a slow time-scale of interaction for magnetic fields inhibiting tamoxifen's antiproliferative action in human breast cancer cells.
  • Rosen LA et al. (1998): A 0.5 G, 60 Hz magnetic field suppresses melatonin production in pinealocytes.
  • Harland JD et al. (1997): Environmental magnetic fields inhibit the antiproliferative action of tamoxifen and melatonin in a human breast cancer cell line.
  • Mevissen M et al. (1996): Exposure of DMBA-treated female rats in a 50-Hz, 50 microTesla magnetic field: effects on mammary tumor growth, melatonin levels, and T lymphocyte activation.
  • Liburdy RP et al. (1993): ELF magnetic fields, breast cancer, and melatonin: 60 Hz fields block melatonin's oncostatic action on ER+ breast cancer cell proliferation.