Expression of the NLRP12/NF-κB/iNOS axis in lung tissues across stages of non-small cell lung cancer and its mechanism in mediating immune cell regulation.

BACKGROUND: Patients with lung squamous cell carcinoma (LUSC), a subtype of non-small cell lung cancer (NSCLC), face a dismal prognosis. Immune evasion driven by an imbalanced tumor immune microenvironment (TIME) and an abnormal enrichment of regulatory T cells (Tregs) is a central pathogenic mechanism, yet the regulatory pathways involved remain elusive. This study aims to investigate the expression profile and immunomodulatory mechanism of the NLR family pyrin domain containing 12 (NLRP12)/nuclear factor kappa B subunit 1 (NF-κB)/inducible nitric oxide synthase (iNOS) axis in LUSC, and to identify potential prognostic biomarkers and therapeutic targets. METHODS: We integrated bioinformatics analysis from databases such as gene expression profiling interactive analysis (GEPIA) and Kaplan-Meier Plotter with experimental validation in 48 clinical LUSC samples. Complementary in vitro models, including CD4+ T cell overexpression/silencing, pathway intervention, and co-culture assays, were employed. Mechanisms were verified using western blotting (WB), quantitative real-time polymerase chain reaction (qPCR), and flow cytometry. RESULTS: NLRP12 was highly expressed in LUSC and correlated with shortened overall survival (OS). Its expression showed a negative correlation with p-NF-κB and iNOS levels during tumor progression. Functionally, NLRP12 promoted the differentiation of CD4+ T cells into Tregs by inhibiting NF-κB phosphorylation and subsequent iNOS expression. The interleukin (IL)-10/transforming growth factor beta 1 (TGF-β) secreted by these NLRP12-driven Tregs enhanced the proliferation and invasion of LUSC cells in vitro, an effect reversed by neutralizing antibodies. CONCLUSIONS: NLRP12 serves as a specific prognostic biomarker in LUSC. The NLRP12/NF-κB/iNOS/Treg axis remodels the TIME to foster tumor progression, offering a novel target and experimental rationale for precision diagnosis and therapy in LUSC.