Nanosecond pulsed current under plasma-producing conditions induces morphological alterations and stress fiber formation in human fibrosarcoma HT-1080 cells.

Cold atmospheric plasma (CAP) is a promising means for various biomedical applications, including cancer therapy. Although the biological action of CAP is considered to be brought about by synergistic effects of reactive species and electrical factors of CAP, limited information is currently available on the contribution of electrical factors to CAP-induced cell responses. We have previously demonstrated that nanosecond pulsed current (nsPC) under CAP-producing conditions significantly promoted the motility of human HT-1080 cells. In this study, we explored the effects of nsPC on cell morphology associated with cell motility. We observed that nsPC stimulation caused extended cell shape, membrane protrusion formation, and increased cell surface area, but not cell death induction. nsPC stimulation also caused elevated intracellular ROS and Ca. HT-1080 cells can undergo two modes of cell motility, namely mesenchymal and ameboid motility, and we found that morphological features of mesenchymal motility was partly shared with nsPC-stimulated cells. Furthermore, nsPC-stimulated cells had extended stress fibers composed of filamentous actin. Taken together, this study provides a novel insight into the electrical aspect of CAP action, and we speculate that nsPC activates a certain mechanism involving intracellular signaling for stress fiber formation, leading to altered cell morphology and increased cell motility.