To study the response of two proliferating human cell lines (neuroblastoma and hepatocarcinoma) to a 42 h, intermittent exposure with a weak magnetic field, alone or in combination with all-trans-retinol (a retinoid applied in oncostatic therapies).
The cell samples were submitted to one of the following treatment combinations: 1) magnetic field exposure and all-trans-retinol treatment (0.5 µg/ml) , 2) magnetic field exposure alone, 3) all-trans-retinol treatment alone or 4) no treatment at all.
The work is part of the REFLEX project funded by the European Union.
Exposure duration: 3 h on/3 h off during 42 h
|Setup||two pairs of Helmholtz coils with a coil diameter of 20 cm and 1000 turns of enameled copper wire, aligned coaxially 10 cm apart; cell culture dishes placed inside the coil system; each coil pair installed separately in the center of a magnetically shielded chamber (co-netic alloy), placed inside an incubator|
|Sham exposure||A sham exposure was conducted.|
|magnetic flux density||100 µT||-||measured||-||-|
The data showed that the two treatments (magnetic field and all-trans-retinol) significantly enhanced cell proliferation in both cell lines, when administered separately. In NB69 cells, simultaneous exposure (co-exposure) induced an additive increase in cell proliferation, associated with increased DNA content. By contrast, in HepG2 cells the all-trans-retinol-induced cell proliferation and increased protein content were partially blocked by the simultaneous exposure to the magnetic field.
In conclusion, these data showed that both agents (magnetic field and all-trans-retinol) induced a proliferative response in the two human cell lines. However, significant differences were observed between the responses of the two cell types to the co-exposure, indicating that the underlying mechanisms is cell type-specific.