Gemcitabine-induced neutrophil extracellular traps via interleukin-8-CXCR1/2 pathway promote chemoresistance in pancreatic cancer.

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive cancers, and chemoresistance poses a significant challenge in its treatment. Neutrophil extracellular traps (NETs) have emerged as key players in the tumour microenvironment, but their role in chemoresistance remains unclear.

METHODS

We investigated the involvement of NETs in PDAC chemoresistance using patient tumour samples, in vitro assays with gemcitabine (GEM)-treated PDAC cells, and in vivo mouse models. We evaluated cytokine production, NET formation and tumour response to GEM, with or without the CXCR1/2 inhibitor navarixin.

RESULTS

NETs are significantly accumulated in the tumours of PDAC patients exhibiting poor response to chemotherapy. GEM-treated PDAC cells secrete pro-inflammatory cytokines such as interleukin-8 (IL-8). IL-8 promote the formation of chemotherapy-induced NETs (chemoNETosis) through activation of CXCR 1/2 on neutrophils. Importantly, treatment with navarixin significantly suppressed chemoNETosis, restored sensitivity to GEM, and significantly reduced tumour growth in vivo.

CONCLUSIONS

Our findings reveal that NETs contribute to chemoresistance in PDAC and that IL-8-mediated chemoNETosis plays a pivotal role in this process. Inhibition of CXCR1/2-mediated NET formation enhances the efficacy of GEM. This approach may represent a promising therapeutic strategy for overcoming chemoresistance in PDAC. These results support further clinical investigation of anti-NETs therapies.