Effects of nano-second electrical pulses (nsPEFs) on cell cycle progression and susceptibility at various phases

Abstract

Exposure to nano-second pulsed electrical fields (nsPEFs) has been shown to cause poration of external and internal cell membranes, DNA damage, and blebbing of the plasma membrane. Recovery from nsPEF exposure is likely dependent on multiple factors, including exposure parameters, length of time between pulses, and extent of cellular damage. As cells progress through the cell cycle, variations in DNA and nucleus structure, cytoskeletal arrangement, and elasticity of cell membrane could cause nsPEFs to affect cells differently during different cell cycle phases. To better understand the impact of nsPEF on cell cycle, we investigated CHO cell cycle progression following varying intensities of nsPEFexposures. Cell populations were examined post exposure (10 ns pulse trains at 100, 150, or 200kV/cm) by analysis of DNA content via propidium iodide staining and flow cytometric analysis to determine cell cycle phase. Populations exhibited arrest in G2/M phase, but not in G1 phase at 1h post-exposure that increased in severity and duration with increasing exposure dose. Recovery from arrest was complete after 12h, and populations did not exhibit an increase in apoptosis as a result of exposure. Post exposure arrest in G2/M phase may indicate that nsPEF-induced damage is not significant to cause G1 arrest or that mitotic checkpoints are more important regulators of cell cycle progression after nsPEF exposure.

Nanosecond Pulsed Electric Field Only Transiently Affects the Cellular and Molecular Processes of Leydig Cells

“…The exposure of cells of the same origin, but at different cycle phases, can produce divergent results. Jurkat cells appeared to be more sensitive to nsPEFs in the G2/M phase than in the G1/S phase [ 73 ]. Monitoring cell distribution at a specified cell cycle phase, we did not observe cell cycle arrest in the G2/M phase, unlike previous studies performed on Chinese hamster ovary (CHO) cells [ 73 , 74 ].…”

“…Jurkat cells appeared to be more sensitive to nsPEFs in the G2/M phase than in the G1/S phase [ 73 ]. Monitoring cell distribution at a specified cell cycle phase, we did not observe cell cycle arrest in the G2/M phase, unlike previous studies performed on Chinese hamster ovary (CHO) cells [ 73 , 74 ]. Instead, a lower proportion of the G2/M phase was visible at 4 h after treatment compared to the sham samples.…”