B3GNT3 facilitates NFKB2 processing and non-canonical NF-κB activation to drive lung adenocarcinoma progression

Aberrant glycosylation is implicated in tumor progression. However, the role of β-1,3-N-acetylglucosaminyltransferase 3 (B3GNT3) in non-small cell lung cancer (NSCLC) remains poorly understood. Public cancer databases and clinical specimens were analyzed to evaluate the expression pattern and prognostic value of B3GNT3 in NSCLC. Gain- and loss-of-function approaches were employed to investigate the effects of B3GNT3 on lung adenocarcinoma (LUAD) cell proliferation, cell cycle progression, invasion, anoikis resistance in vitro, and tumor growth in vivo. Transcriptomic profiling identified B3GNT3-associated signaling pathways. Protein-protein interactions were examined using immunoprecipitation coupled with mass spectrometry and co-immunoprecipitation assays, followed by functional validation through genetic ablation studies. A catalytic inactive mutant of B3GNT3 was generated to assess whether its oncogenic function depends on glycosyltransferase activity. B3GNT3 was frequently upregulated in NSCLC tissues and significantly correlated with poor prognosis. Functional studies demonstrated that B3GNT3 promoted LUAD cell proliferation, anchorage-independent growth, invasion, anoikis resistance, and xenograft tumor growth. Transcriptomic analyses linked B3GNT3 to epithelial-mesenchymal transition (EMT) and NF-κB signaling. Mechanistically, B3GNT3 physically interacted with NFKB2, facilitating p100 phosphorylation, processing into p52, and nuclear accumulation, thereby activating non-canonical NF-κB signaling. Genetic ablation of NFKB2 markedly reversed the oncogenic effects of B3GNT3, including altered cell cycle gene expression, EMT-associated gene expressions, enhanced invasive capacity, anoikis resistance, and accelerated tumor growth. Importantly, catalytic inactivation of B3GNT3 did not impair its ability to interact with NFKB2 or to promote p100 processing and EMT-related phenotypes, indicating that its tumor-promoting function is largely independent of glycosyltransferase activity. Our study identifies B3GNT3 as a novel oncogenic driver in LUAD and reveals a B3GNT3-NFKB2 signaling axis that promotes tumor progression through non-canonical NF-κB activation in a catalysis-independent manner. These findings suggest that therapeutic strategies targeting B3GNT3-mediated signaling interactions, rather than enzymatic activity alone, may represent a potential approach for LUAD treatment. Not applicable.