Targeting ESE3/EHF with Nifurtimox inhibits CXCR2+ neutrophil infiltration and overcomes pancreatic cancer resistance to chemotherapy and immunotherapy.

BACKGROUND & AIMS: Since 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 SNP sequencing, single-cell RNA sequencing, and spatial transcriptomics. Ehf-knockout mice, KPC (LSL-KrasG12D/+ , LSL-Trp53R172H/+ 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 CXCR2+neutrophils. In addition, multiplexed cytokines assays and chromatin immunoprecipitation assays were employed 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 immuno-therapy resistance in clinical cohorts and pre-clinical syngeneic mice models. Mechanistically, EHF deficiency induced 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 scRNA-seq 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.