Innovative Therapeutic Approach Targeting Colon Cancer Stem Cells: Transitional Cold Atmospheric Plasma

Transitional cold atmospheric plasma (TCAP) represents a novel technique for generating plasma remotely from a primary source. It consists of a partially nonthermal ionized gas mixture containing charged and neutral particles, photons, and free radicals. In recent years, TCAP has attracted considerable attention in biomedical applications. In order to evaluate colon cancer stem cells’ (CCSCs) proliferation, apoptotic induction, inflammatory response, and survival, TCAP was utilized both directly and indirectly in this study. Using argon and helium gases, TCAP was continuously delivered in two stages during the experiment. For direct state, TCAP was irradiated onto CCSCs for 3 and 5 min. In the indirect technique, Matrigel was treated with TCAP for 5 min before the introduction of cells. In vitro assays demonstrated that TCAP exposure significantly reduced the viability of CCSCs; helium gas and direct application had greater impacts than argon. Numerous investigations confirmed the induction of apoptosis, showing that the treated groups had more apoptotic cells and altered cellular structures than controls (****p < 0.0001). A substantial increase in the Bax/Bcl-2 ratio was found by analyzing the expression of the Bax and Bcl-2 genes, indicating increased susceptibility to apoptosis (*p = 0.0177 and ***p = 0.0004). The higher efficacy of the direct helium mode was further highlighted by inflammatory marker analysis, which showed a significant reduction in interleukin-6 and interleukin-8 expression in cells directly treated with TCAP-helium compared to TCAP-argon (**p = 0.0015 and ***p = 0.0007). Lastly, the proliferation test, which relies on K_i-67 expression, demonstrated a noteworthy decline in all TCAP-treated groups, with the direct helium group exhibiting the most robust impact (**p = 0.0014). Overall, the findings highlight the potential of TCAP, particularly with helium, as a promising approach for selectively targeting CCSCs and providing insights into its therapeutic mechanisms for cancer treatment. TCAP, therefore, emerges as a unique therapeutic strategy with potential applications in cancer stem cell-targeted therapies.