[Millimeter wave exposure induces apoptosis in human melanoma A375 cells in vitro].

Abstract

OBJECTIVE\nTo investigate the effects of millimeter wave (MMW) exposure on apoptosis of human melanoma A375 cells and explore the mechanisms.\n\n\nMETHODS\nThrough electromagnetic field calculation we simulated MMW exposure in cells and calculated the specific absorption rate (SAR). The optimal irradiation parameters were determined according to the uniformity and intensity of the SAR. A375 cells were then exposed to MMV for 15, 30, 60, or 90 min, with or without pretreatment with the caspase-3 inhibitor AC-DEVD-fmk (10 μmol/L) for 1 h at 90 min before the exposure. CCK-8 assay was used to assess the changes in the viability and Annexin-V/ PI staining was used to detect the apoptosis of the cells following the exposures; Western blotting was used to detect the expression of caspase-3 in the cells.\n\n\nRESULTS\nThe results of electromagnetic field calculation showed that for optimal MMV exposure, the incident field needed to be perpendicular to the bottom of the plastic Petri dish with the antenna placed below the dish. CCk-8 assay showed that MMW exposure significantly inhibited the cell viability in a time-dependent manner (P < 0.05); exposures for 15, 30, 60, and 90 min all resulted in significantly increased apoptosis of the cells (P < 0.05). The cells with MMW exposure showed significantly increased expression of caspase-3. The inhibitory effect of MMW on the cell viability was antagonized significantly by pretreatment of the cells with AC-DEVD-fmk (P < 0.05), which increased the cell viability rate from (36.7±0.09)% to (59.8±0.06)% (P < 0.05).\n\n\nCONCLUSIONS\n35.2 GHz millimeter wave irradiation induces apoptosis in A375 cells by activating the caspase-3 protein.