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Therapy resistance is responsible for most cancer-related death and is mediated by the unique ability of cancer cells to leverage metabolic conditions, signaling molecules, redox status, and other pathways for their survival. Interestingly, many cancer survival pathways are susceptible to disturbances in cellular reactive oxygen species (ROS) and may therefore be disrupted by exogenous ROS. Here, we explore whether trident cold atmospheric plasma (Tri-CAP), a gas discharge with exceptionally low-level ROS, could inhibit multiple cancer survival pathways together in a murine cell line model of therapy-resistant chronic myeloid leukemia (CML). We show that Tri-CAP simultaneously disrupts three cancer survival pathways of redox deregulation, glycolysis, and proliferative AKT/mTOR/HIF-1α signaling in this cancer model. Significantly, Tri-CAP blockade induces a very high rate of apoptotic death in CML cell lines and in primary CD34+ hematopoietic stem and progenitor cells from CML patients, both harboring the therapy-resistant T315I mutation. In contrast, nonmalignant controls are minimally affected by Tri-CAP, suggesting it selectively targets resistant cancer cells. We further demonstrate that Tri-CAP elicits similar lethality in human melanoma, breast cancer, and CML cells with disparate, resistant mechanisms and that it both reduces tumor formation in two mouse models and improves survival of tumor-bearing mice. For use in patients, administration of Tri-CAP may be extracorporeal for hematopoietic stem cell transplantation therapy, transdermal, or through its activated solution for infusion therapy. Collectively, our results suggest that Tri-CAP represents a potent strategy for disrupting cancer survival pathways and overcoming therapy resistance in a variety of malignancies. [ABSTRACT FROM AUTHOR]

Natural killer (NK) cells comprise one subset of the innate lymphoid cell (ILC) family. Despite reported antitumor functions of NK cells, their tangible contribution to tumor control in humans remains controversial. This is due to incomplete understanding of the NK cell states within the tumor microenvironment (TME). Here, we demonstrate that peripheral circulating NK cells differentiate down two divergent pathways within the TME, resulting in different end states. One resembles intraepithelial ILC1s (ieILC1) and possesses potent in vivo antitumor activity. The other expresses genes associated with immune hyporesponsiveness and has poor antitumor functional capacity. Interleukin-15 (IL-15) and direct contact between the tumor cells and NK cells are required for the differentiation into CD49a+CD103+ cells, resembling ieILC1s. These data explain the similarity between ieILC1s and tissueresident NK cells, provide insight into the origin of ieILC1s, and identify the ieILC1-like cell state within the TME to be the NK cell phenotype with the greatest antitumor activity. Because the proportions of the different ILC states vary between tumors, these findings provide a resource for the clinical study of innate immune responses against tumors and the design of novel therapy. [ABSTRACT FROM AUTHOR]