Targeting ESE3/EHF With Nifurtimox Inhibits CXCR2⁺ Neutrophil Infiltration and Overcomes Pancreatic Cancer Resistance to Chemotherapy and Immunotherapy

Background & Aims: Because pancreatic cancer responds poorly to chemotherapy and immunotherapy, it is necessary to identify novel targets and compounds to overcome resistance to treatment. Methods: This study analyzed genomic single nucleotide polymorphism sequencing, single-cell RNA sequencing, and spatial transcriptomics. Ehf-knockout mice, KPC (LSL-Kras^G12D/+, LSL-Trp53^R172H/+ and Pdx1-Cre) mice, CD45.1⁺ BALB/C nude mice, and CD34⁺ humanized mice were also used as subjects. Multiplexed immunohistochemistry and flow cytometry were performed to investigate the proportion of tumor-infiltrated C-X-C motif chemokine receptor 2 (CXCR2)⁺ neutrophils. In addition, multiplexed cytokines assays and chromatin immunoprecipitation assays were used to examine the mechanism. Results: The TP53 mutation–mediated loss of tumoral EHF increased the recruitment of CXCR2⁺ neutrophils, modulated their spatial distribution, and further induced chemo- and immunotherapy resistance in clinical cohorts and preclinical syngeneic mice models. Mechanistically, EHF deficiency induced C-X-C motif chemokine ligand 1 (CXCL1) transcription to enhance in vitro and in vivo CXCR2⁺ neutrophils migration. Moreover, CXCL1 or CXCR2 blockade completely abolished the effect, indicating that EHF regulated CXCR2⁺ neutrophils migration in a CXCL1-CXCR2–dependent manner. The depletion of CXCR2⁺ neutrophils also blocked the in vivo effects of EHF deficiency on chemotherapy and immunotherapy resistance. The single-cell RNA-sequencing results of PDAC treated with Nifurtimox highlighted the therapeutic significance of Nifurtimox by elevating the expression of tumoral EHF and decreasing the weightage of CXCL1–CXCR2 pathway within the microenvironment. Importantly, by simultaneously inhibiting the JAK1/STAT1 pathway, it could significantly suppress the recruitment and function of CXCR2⁺ neutrophils, further sensitizing PDAC to chemotherapy and immunotherapies. Conclusions: The study demonstrated the role of EHF in the recruitment of CXCR2⁺ neutrophils and the promising role of Nifurtimox in sensitizing pancreatic cancer to chemotherapy and immunotherapy.