[An experimental attempt to potentiate therapeutic effects of combined use of pulsing magnetic fields and antitumor agents].

With a view to examining the possible clinical applicability of pulsing magnetic fields (PMF), we investigated the effects of weak, non-heat inducing, PMF on DNA synthesis and sensitivity of cancer cells to antitumor agents. Leukemic T-cells (Molt-4) and a pancreatic ductal adenocarcinoma (solid tumor) transplanted in a Syrian golden hamster were used for the in vitro experiment and in vivo experiment respectively. In order to evaluate the effects of PMF on the DNA synthesis of cancer cells and the incorporation of antitumor agent into cancer cells, cultured cells or solid tumor were exposed to PMF generated by a solenoid coil immediately after 3H-or 14C-thymidine and 3H-methotrexate administration respectively. Thymidine uptake was found to increase by exposure to PMF, as did also 3H-methotrexate uptake by leukemic T-cells. Following exposure to PMF immediately after administration of methotrexate or mitomycin C, antitumor activity in both cells was increased. From these results it appears that the incorporation of antitumor agents into the cells increases by eddy current stimulation induced by PMF, and that the cell cycle shifts from the non-proliferative to proliferative phase, resulting in increased antitumor activity.