Caspase-3 Activation by Exponential Decay Nanosecond Pulsed Electric Fields on Tumor-Bearing BALB/c Nude Mice In Vivo

In order to study the apoptosis-induction effects of exponential decay nanosecond pulsed electric fields (EDnsPEF) in vivo, tumor models in 20 female BALB/c nude mice were established by inoculating them with human melanoma cells A375. These mice were randomly divided into treated group (exposed to EDnsPEF with intensity of 20 kV/cm and duration of 300 ns) and control group equally. Twenty days later, tumor growth in the treated group was effectively inhibited (P <; 0.01 compared with that in control group), typical morphological apoptosis characteristics in ultrastructure were observed by transmission electron microscope, and expression of caspase-3 and caspase-3 messenger ribonucleic acid were obviously increased (P <; 0.01) using immunofluorescence and RT-PCR, respectively. These experimental results contributed evidence of tumor-growth inhibition by EDnsPEF exposure in vivo. The mechanism was apoptosis-induction effects of EDnsPEF on cancer cells by activating caspase-3. This study presented in vivo evidence of caspase-3 activation for apoptosis-induction effects of EDnsPEF, and this supported possible drug-free tumor therapy utilizing EDnsPEF.