FUT3–B3GNT3 interaction promotes pancreatic cancer progression and chemoresistance via NF-κB signaling mediated autophagy

Pancreatic ductal adenocarcinoma (PDAC) is prone to drug resistance and a role for fucosyltransferase 3 (FUT3) is increasingly recognized. The current study investigated the mechanisms by which FUT3 contributes to PDAC. FUT3 expression was analyzed via bioinformatics and validated by immunohistochemistry (IHC). RNA sequencing analysis identified significantly upregulated genes in Gemcitabine (Gem)-resistant cells of PDAC(ASPC-1/Gem). The IC50 values, proliferative capacity, invasive potential, and migratory behavior of ASPC-1/Gem cells were quantitatively assessed using using Cell Counting Kit-8 (CCK-8), 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), wound healing, and transwell assays, respectively. Subcellular localization and autophagy were analyzed by immunofluorescence (IF) and electron microscopy. Molecular interactions and signaling pathways were probed through co-immunoprecipitation (Co-IP), reverse transcription quantitative PCR (RT-qPCR) and Western blotting. A FUT3-knockdown mouse xenograft tumor model was established to assess in vivo tumorigenesis. High FUT3 expression correlated with chemoresistance and poor survival in PDAC patients. FUT3 knockdown suppressed autophagy, progression, and chemoresistance in both cell and animal models, while overexpression reversed these impacts. Mechanistically, FUT3 bound to β-1,3-N-acetylglucosaminyltransferase 3 (B3GNT3) to activate Nuclear Factor-kappa B (NF-κB) signal transduction, driving autophagy, progression and chemoresistance. Our results reveal that FUT3 interacts with B3GNT3 and activates the NF-κB signaling, amplifying autophagic activity to drive PDAC progression and confer chemoresistance.