Abstract 3600: MET-mediated STING activation regulates EMT and NF-ΚB pathway in non-small cell lung cancer

Abstract

Abstract The cyclic GAMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway is known to have anti-tumor activity by activating the innate immune response against cytosolic double-stranded DNA (dsDNA). The regulating mechanism of STING remains unclear, and a pro-tumorigenic effect of STING pathway was recently reported. In this study, we investigated the expression of STING by MET and a novel role of the STING pathway in non-small cell lung cancer (NSCLC). The Cancer Genome Atlas (TCGA) and Cancer Cell Line Encyclopedia (CCLE) analysis showed that cGAS/STING pathway is enriched and STING expression is higher in MET-overexpressing tumors. Western blot for NSCLC cells and immunohistochemistry for NSCLC tumor tissues showed positive correlation between MET and STING expression in NSCLC cells. MET-overexpression and a MET agonist (HGF) treatment increased STING expression and CXCL10 and IFNβ expression and secretion, whereas MET-knockdown and a MET inhibitor (capmatinib) treatment decreased STING expression in NSCLC cells. In MET-positive and STING-positive cells, a STING agonist (poly-dAdT and diABZI) treatment led to increased activation of STING signaling pathway. In EBC-1 cells, MET knockdown decreased STING expression and STING-agonist-induced STING-pathway activation and cytokine production. To further investigate the role STING in NSCLC, EBC-1 cells were transfected with STING siRNA and submitted to RNS-seq. Gene set enrichment analysis revealed that several pathways were affected by STING expression. Epithelial-mesenchymal transition (EMT) and TNFα-signaling via NF-κB signaling were significantly downregulated in STING-knockdowned cells. In vitro experiments using EBC-1 cells, STING overexpression increased SLUG and TWIST1 expression and migration of cells, whereas STING knockdown decreased SLUG and TWIST1 expression and migration of cells. In summary, this study demonstrated that MET and STING expression were positively correlated with each other in NSCLC and MET overexpression increased STING expression and subsequent activation upon STING agonist stimulation. In addition, STING contributed to EMT in NSCLC. Citation Format: Seungchan Mun, Bogyeong Han, HyunKyung Ahn, Jaemoon Koh, Sehui Kim, DooHyun Chung, YoonKyung Jeon. MET-mediated STING activation regulates EMT and NF-ΚB pathway in non-small cell lung cancer. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3600.