Abstract

Background Non-small cell lung cancer (NSCLC) is the predominant lung cancer subtype with high mortality rate. Drug resistance and immune evasion limit its therapeutic outcomes. Specific mechanism of the oncogenic ZFP36L1 in NSCLC remains unclear. Methods scRNA-seq data were analysed using bioinformatic approaches. Hypoxia-induced alterations in the macrophage CXCL9:SPP1 ratio were assessed by qRT-PCR, Western blot (WB), immunofluorescence, flow cytometry and ELISA. Dual-luciferase reporter and ChIP assays were used to validate ZFP36L1-mediated transcriptional regulation of SPP1. In a co-cultivation system of macrophages and NSCLC cells, tumour cell malignancy was evaluated through flow cytometry, CCK-8, Transwell, colony formation and scratch assays. Patient-derived organoids co-cultured with macrophages were analysed via H&E, EdU and CellTiter-Glo assays for pathological changes, proliferation and viability, as well as qRT-PCR and WB for the expression of apoptosis-related proteins. Finally, through a macrophage-specific ZFP36L1-knockout mouse model, the function of ZFP36L1 in CXCL9:SPP1 polarity and NSCLC progression was validated in vivo. Results Hypoxia induced an imbalanced macrophage CXCL9:SPP1 ratio, with more pro-tumour SPP1 + macrophages and fewer anti-tumour CXCL9 + macrophages. Upregulation of ZFP36L1 promoted macrophage polarisation towards the SPP1 + phenotype, which then bound to CD44 on tumour cells to accelerate NSCLC progression. Conclusion Under hypoxia, ZFP36L1 transcriptionally regulates SPP1 to reduce the macrophage CXCL9:SPP1 ratio, thereby driving NSCLC malignancy.