Growth of injected melanoma cells is suppressed by whole body exposure to specific spatial-temporal configurations of weak intensity magnetic fields

Abstract

Purpose: To measure the effect of exposure to a specific spatial-temporal, hysiologically-patterned electromagnetic field presented using different geometric configurations on the growth of experimental tumours in mice.

Methods: C57b male mice were inoculated subcutaneously with B16-BL6 melanoma cells in two blocks of experiments separated by six months (to control for the effects of geomagnetic field). The mice were exposed to the same time-varying electromagnetic field nightly for 3 h in one of six spatial configurations or two control conditions and tumour growth assessed.

Results: Mice exposed to the field that was rotated through the three spatial dimensions and through all three planes every 2 sec did not grow tumours after 38 days. However, the mice in the sham-field and reference controls showed massive tumours after 38 days. Tumour growth was also affected by the intensity of the field, with mice exposed to a weak intensity field (1–5 nT) forming smaller tumours than mice exposed to sham or stronger, high intensity (2–5 μT) fields. Immunochemistry of tumours from those mice exposed to the different intensity fields suggested that alterations in leukocyte infiltration or vascularisation could contribute to the differences in tumour growth.

Conclusions: Exposure to specific spatial-temporal regulated electromagnetic field configurations had potent effects on the growth of experimental tumours in mice.

Keywords:

• frequency-modulated
• magnetic fields
• mice
• melanoma
• nocturnal exposures
• spatial configurations

Acknowledgements

Special thanks to Chris Bloome for his assistance with care of the animals.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.

Note

A recent report by V.V. Novikov, G.V. Novikov, and E.E. Fesenko (2009) [Effect of weak combined static and extremely low-frequency alternating magnetic fields on tumor growth in mice inoculated with the Ehrlich ascites carcinoma. Bioelectromagnetics 30:343] has described potent anti-tumor effects of low intensity (100–300 μT), low frequency (1–16.5 Hz) alternating magnetic fields on mice transplanted with the Ehrlich carcinoma. The conclusions from this study are in support of what we have reported using a different model system.