CXCL6 Reshapes Lipid Metabolism and Induces Neutrophil Extracellular Trap Formation in Cholangiocarcinoma Progression and Immunotherapy Resistance.

The chemokine CXCL6 is identified as a pivotal regulator of biological processes across multiple malignancies. However, its function in cholangiocarcinoma (CCA) is underexplored. Tumor profiling for CXCL6 is performed using a public database. Both in vitro and in vivo experiments are utilized to evaluate the oncogenic effects of CXCL6 on CCA. Additionally, RNA-Seq is employed to detect transcriptomic changes related to CXCL6 expression in CCA cells and neutrophils. Molecular docking, fluorescence colocalization, and Co-IP are used to elucidate a direct interaction between JAKs and CXCR1/2. Additionally, LC-MS lipidomics and explored the impact of CXCL6 on immunotherapy in vivo. CXCL6 is upregulated in CCA tissues and promoted the proliferation and metastasis of CCA. Mechanistically, CXCL6 regulated the CXCR1/2-JAK-STAT/PI3K axis in CCA via autocrine signaling, leading to lipid metabolic reprogramming, and promoted neutrophil extracellular traps (NETs) formation by activating the RAS/MAPK pathway in neutrophils. Eventually, NETs formation induced immunotherapy resistance in CCA by blocking CD8+T cell infiltration. CXCL6 modulates CCA progression through the CXCR1/2-JAK-STAT/PI3K axis and reshaping its lipid metabolism. CXCL6 also mediates immunotherapy resistance through NETs, which may be a potential therapeutic target and biomarker for CCA.