Multi-omics analysis identifies PUS7 as an immune modulator driving NETs-mediated macrophage polarization in pancreatic cancer.

Pseudouridine synthases (PUS) have been implicated in various cancers, yet their roles in pancreatic cancer immunity remain unclear. Through integrative multi-omics analyses combining genomics, transcriptomics, and clinical datasets, we evaluated associations between PUS family genes and oncogenic features, including tumour microenvironment scores, immune infiltration, cancer stemness, and prognosis. Among them, PUS7 and PUS3 showed the strongest correlations with tumour-promoting phenotypes, with high PUS7 expression in PDAC predicting poor overall survival. Functional assays revealed that PUS7 overexpression markedly enhanced PDAC cell proliferation, migration, and invasion. Transcriptomic profiling demonstrated that PUS7 promotes neutrophil extracellular traps formation, identifying it as a key regulator of NET-mediated immune modulation. Single-cell RNA sequencing of orthotopic mouse models showed PUS7 overexpression reduced macrophage infiltration and skewed macrophage polarization towards the M2 phenotype while suppressing M1 polarization. We found that PUS7 reshapes the PDAC immune landscape primarily by inducing NETs, which drive macrophage polarization from M1 to M2, fostering immune suppression and tumour progression. The PUS7-NET-M2/M1 axis thus represents a novel mechanism of PDAC pathogenesis and a potential therapeutic target in this lethal malignancy. HIGHLIGHTS: PUS7 enhances pancreatic ductal adenocarcinoma progression by modulating the tumour immune microenvironment. PUS7 induces neutrophil extracellular trap formation within pancreatic tumours. NETs reprogram tumour-associated macrophages from an M1 to an M2 phenotype, promoting immune suppression.