Low voltage irreversible electroporation induced apoptosis in HeLa cells

Abstract

High-voltage electric field pulses can make cell membrane electroporated irreversibly and eliminate malignant cells via necrosis. However, low-voltage is not efficient as that. This study determined the differential effects of high- and low-voltage electric field pulses on HeLa cells, when the power of low-voltage was enhanced by increasing quantity of pulses. Pulses electric fields with permanent frequency (1 Hz) and pulse length (100 μs) were performed on HeLa cells. Voltage and pulse sets (8 pulses/set) were various during treatment. CCK-8 assay was used to detect cell viability. The quantitative determination of apoptosis and necrosis were performed by flow cytometry with Annexin V and PI staining. Transmission electron microscopy was used to observe the ultrastructure of HeLa cells. Caspase-3 and caspase-8, the enzymes in apoptotic pathway, were determined by western blot. The data showed that low-voltage electric field pulses also could make cell irreversible electroporation (IRE) and ablate HeLa cells effectively by induction of apoptosis. The ablating effect due to low-voltage treatments delivered with a greater number of pulses may be as satisfactory as high-voltage, or even preferable because it causes less necrosis and more apoptosis. IRE induced by low voltage with more pulses could ablate HeLa cells effectively as high voltage, and it was preferable that less necrosis and more apoptosis occurred under such condition.