Usenamine A triggers NLRP3/caspase-1/GSDMD-mediated pyroptosis in lung adenocarcinoma by targeting the DDX3X/SQSTM1 axis.

BACKGROUND: Usenamine A (C18H17NO6) is a newly developed, natural anticancer drug that reportedly exerts low toxicity. The therapeutic efficacy and underlying mechanisms of usenamine A in lung adenocarcinoma (LUAD) remain poorly understood. We aimed to explore the therapeutic effects and molecular mechanisms through which usenamine A inhibits LUAD tumorigenesis. METHODS: We used LUAD cell lines H1299 and A549 in the present study. CCK-8 and colony formation assays were performed to analyze cell proliferation. Cell migration, invasion, and apoptosis were evaluated using wound-healing, transwell, and flow cytometric assays, respectively. Levels of reactive oxygen species were measured using a DCFH-DA probe. Inflammatory factors (lactate dehydrogenase, interleukin [IL]-1ß, and IL-18) were detected using enzyme-linked immunosorbent assays. Western blotting was performed to determine the expression of NOD-like receptor pyrin 3 (NLRP3)/caspase-1/gasdermin D (GSDMD) pathway-related proteins. Pyroptosis was detected using transmission electron microscopy. The interaction and co-localization of DDX3X and sequestosome 1 (SQSTM1) were identified using co-immunoprecipitation and immunofluorescence assays, respectively. For in vivo assessment, we established a xenograft model to validate the usenamine A-mediated effects and mechanisms of action in LUAD. RESULTS: Usenamine A inhibited the proliferation, migration, and invasion of LUAD cells. Furthermore, usenamine A induced NLRP3/caspase-1/GSDMD-mediated pyroptosis in LUAD cells. Usenamine A upregulated DDX3X expression to trigger pyroptosis. DDX3X interacted with SQSTM1, which is responsible for inducing pyroptosis. In vivo, usenamine A suppressed LUAD tumorigenesis by triggering NLRP3/caspase-1/GSDMD-mediated pyroptosis via the upregulation of the DDX3X/SQSTM1 axis. CONCLUSIONS: Usenamine A was found to induce NLRP3/caspase-1/GSDMD-mediated pyroptosis in LUAD by upregulating the DDX3X/SQSTM1 axis.

Nucleophosmin promotes lung adenocarcinoma cell proliferation, migration and invasion by activating the EGFR/MAPK signaling pathway.

Lung adenocarcinoma (LUAD) is the main cause of death globally. The present study investigated the prognostic value and functional verification of nucleophosmin (NPM1) in LUAD. LUAD and normal samples from The Cancer Genome Atlas were analyzed to identify whether NPM1 is associated with LUAD prognosis. NPM1 protein expression level was verified by western blotting. Cell proliferation, migration and invasion were detected by Cell Counting Kit­8, wound healing and Transwell assays, respectively. EGFR/MAPK pathway­related proteins [phosphorylated (p)­EGFR/EGFR, p­MEK/MEK, and p­ERK/ERK] expression was measured through western blotting. A xenograft tumor mice model was constructed to perform the in vivo verification. NPM1 was upregulated in LUAD cells, and high­level NPM1 indicated poor prognosis in patients with LUAD. In vitro experiments revealed that NPM1 knockdown inhibited LUAD cell proliferation, migration and invasion. Moreover, protein expression of p­EGFR/EGFR, p­MEK/MEK and p­ERK/ERK was reduced with the NPM1 silencing. Furthermore, EGF, an activator of the EGFR/MAPK pathway, reversed the effects of NPM1. In vivo experiments showed that NPM1 knockdown inhibited tumor growth and protein levels of p­EGFR/EGFR, p­MEK/MEK and p­ERK/ERK. NPM1 is related to the poor prognosis of LUAD and promotes the malignant progression of LUAD by activating the EGFR/MAPK pathway. This discovery provides a new potential therapeutic target for the diagnosis and treatment of LUAD.