Low voltage irreversible electroporation induced apoptosis in HeLa cells

Abstract

Background: 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.

Aims: 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.

Materials and methods: 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.

Results: 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.

Conclusions: 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.