P28-6 IL-6, IL-8, and VEGF secreted by PC9 and PC9-MET cells may impair the function of NK cells

Natural killer (NK) cells are innate immune effector cells that are efficient in identifying and killing cancer cells through the release of cytokines and cytotoxic enzymes. NK cells are effector lymphocytes with crucial roles in the resistance against various cancers, dysfunction of NK cells often outcomes in advanced cancer progression. However, the functional regulation of NK cells in NSCLC cells (PC9 and gefitinib resistant PC9-MET cells) remains largely unknown. In this study, flow cytometry was applied to profile the activity and function of NK cells. ELISA experiment was performed to quantitate cytokine levels. Here, we demonstrated that NK cells prevented NSCLC cells autophagy. Besides, the effect of NK cells was closely associated with NSCLC cell viability. Mechanistically, PC9 and PC9-MET cells secreted IL-6, IL-8, and VEGF cytokines markedly, leading to the activation of NK cells inhibitory signaling pathways. Exploring NK cells' dysfunction, responsible factors like STAT3, NKp30, NKG2D, etc. could explain the precise mechanism that demanding further research. However, this study gives an idea of NK cell function alteration that can assist in uncovering a novel mechanism participating in NK cell dysfunction.