[The adjuvant killing effect of modulated electro-hyperthermia combined with chemotherapy on B16F10 melanoma cells]

Our aim was to detect the effect of modulated electro-hyperthermia (mEHT) on cell viability and to examine if hyperthermia can augment the cell killing effect of various chemotherapeutic agents. B16F10 melanoma cells were treated for 30, 60, 90 and 120 minutes with mEHT using LabEHY100 (OncothermTM). Cell viability was measured using MTT assay and apoptosis by annexin V/7-AAD staining using flow cytometry 24 hours post-treatment. For analyzing gene expression with qPCR cells were harvested after 60 minutes treatment. In combined protocols, cells were treated with paclitaxel (40 nM), dacarbazine (40 μM) or nutlin-3a (10 μM) after mEHT. mEHT induced nuclear translocation of p53 which in turn regulates pro- and anti-apoptotic gene expression accounting for decreased cell viability. In combination with chemotherapy, mEHT augmented the cell killing effect of dacarbazine or nutlin-3a but not that of paclitaxel determined 48 hours post-treatment. The sensitizing effect on chemotherapeutics demonstrate the efficiency of mEHT as an adjuvant modality in cancer treatment.