Abstract
AIM: We aimed to investigate the synergistic effects of pulsed electromagnetic field (PEMF) and doxorubicin therapy in a mouse osteosarcoma cell line (LM8 cells) in vitro. MATERIALS AND METHODS: The effects of PEMF (5 mT, 200 Hz) of different durations and doxorubicin on the proliferative activity of LM8 cells were measured by the MTT assay. Apoptotic-related factors such as cell-cycle phase, mitochondrial membrane potential, and caspase 3/7 activity were investigated using 4',6-diamidino-2-phenylindole staining and apoptosis kits. Identification of intracellular signaling molecules induced by the combination was comprehensively explored using a stress and apoptosis-related protein array kit. RESULTS: PEMF enhanced the inhibition of cell proliferation mediated by doxorubicin but did not affect the cell cycle, mitochondrial membrane potential, or doxorubicin-induced G(2)/M arrest. The combination of PEMF and doxorubicin altered a few signaling molecules. PEMF tended to reduce the doxorubicin-induced decrease of phosphorylated BAD, while reducing the increased expression of total IĸB and phosphorylated-CHK1 induced by doxorubicin. CONCLUSION: Our results indicate that combination of PEMF and doxorubicin could be a novel chemotherapeutic strategy.