Cold Atmospheric Plasma Reduces Migration and Viability of Oral Squamous Cell Carcinoma Cells and Increases E-Cadherin Expression

Background: Cold atmospheric plasma (CAP) has emerged as a promising experimental anticancer strategy, yet its influence on oral squamous cell carcinoma (OSCC) migration and viability remains moderately understood. The aim of this workpaper was to examine how CAP exposure influences wound closure, WST-1 metabolic signal, and key proteins involved in epithelial adhesion and cell-cycle regulation in OSCC models. Methods: HSC-3 and CAL27 head and neck squamous cell carcinoma (HNSCC) cells were exposed to CAP generated via Piezoelectric Direct Discharge (PDD) technology for 20 s under standardized conditions. Wound closure was assessed by wound-healing assay under proliferation-restricted conditions (50 μM Ara-C), while relative cellular metabolic activity was measured using WST-1. E-cadherin, N-cadherin, and Cyclin A were evaluated by Western blot. Publicly available baseline transcriptomic data were additionally analyzed to characterize migration- and cytoskeleton-related expression patterns in the two HNSCC models. These transcriptomic data were independent of CAP treatment. Results: A 20 s CAP exposure significantly delayed wound closure in both HNSCC cell lines under proliferation-restricted conditions and reduced the WST-1 signal. Cyclin A levels also decreased, supporting an effect on cell growth and cell-cycle regulation, although the available data do not establish cell-cycle arrest. E-cadherin increased after CAP treatment, whereas N-cadherin remained low without a statistically significant change. Baseline transcriptomic mapping further showed differences between HSC-3 and CAL27 in genes related to actin-cytoskeleton organization, focal adhesion, and migration. These data were used to contextualize the experimental phenotype and were not interpreted as CAP-induced transcriptional changes. Conclusions: In these in vitro OSCC models, CAP exposure was associated with slower wound closure, lower WST-1 signal, increased E-cadherin, and reduced Cyclin A expression. These findings suggest further investigation of CAP as a potential modulator of OSCC cellular metabolic activity, adhesion-related markers, and cell-cycle-associated proteins.