Switching "on" and "off" of genes would be a useful tool in gene therapy. In the present study, the possibility was examined to increase the enzyme activity via the insertion of DNA sequences which are sensitive to magnetic fields.
Promoter sequences consisting of cytosine and thymine seem to act as so called "electromagnetic field response elements" (EMREs). Segments of 900 base pairs of the c-myc promoter, containing these EMREs were cloned into constructs of catalase or luciferase, which are otherwise unresponsive to electromagnetic fields. Those constructs were transfected into HeLa cells.
Enzyme activity was measured 30 minutes after a 30 minutes-exposure period. Five groups were examined: 1.) exposed transfected HeLa cells, 2.) sham exposed transfected HeLa cells, 3.) exposed transfected HeLa cells, but without the 900 base pairs of the c-myc promoter containing the EMREs, 4.) non-specific protein samples as a negative control and 5.) at 43°C heat shocked HeLa cells as a positive control.
|Setup||cells in a Plexiglas stand in horizontal position; Helmholtz coils consisted of 19 gauge wire bundles, wound in 164 rectangular turns around a rectangular form (13 x 14 cm) with 8 cm spacing; coils were closed within mu-metal containers for shielding (30 cm high, 15 cm diameter cylindrical container)|
|Sham exposure||A sham exposure was conducted.|
Transfected cells exposed to a 60 Hz-magnetic field (group 1) showed significantly increased enzyme activities of catalase and luciferase in comparison to sham exposed transfected cells (group 2), while no increased enzyme activities were measured in transfected cells without the c-myc-promoter containing the EMREs (group 3).
The data indicate that the regulation of genes could be possible via the insertion of DNA sequences which are sensitive to magnetic fields.