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.
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 duration: continuous, up to 7 days
|Exposure duration||continuous, up to 7 days|
|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.|
|magnetic flux density||1.2 µT||effective value||measured||-||-|
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).