METHODS: Single-cell transcriptome sequencing data from CRC and adjacent normal tissues identified MDSC-related differentially expressed genes. RNA-seq analysis comprehensively profiled MDSC gene expression in murine CRC tumors. LNCs@CSF1R siRNA nanocarriers effectively targeted and inhibited CSF1R. Flow cytometry quantified changes in MDSC surface markers post-CSF1R inhibition. RNA-seq and pathway enrichment analyses revealed the impact of CSF1R on MDSC metabolism and signaling. The effect of CSF1R inhibition on the JAK/STAT3 signaling axis was validated using Colivelin and metabolic assessments. Glucose and fatty acid uptake were measured via fluorescence-based flow cytometry. The efficacy of LNCs@CSF1R siRNA and anti-PD-1, alone and in combination, was evaluated in a murine CRC model with extensive tumor section analyses.
RESULTS: CSF1R played a significant role in MDSC-mediated immune suppression. LNCs@CSF1R siRNA nanocarriers effectively targeted MDSCs and inhibited CSF1R. CSF1R regulated MDSC fatty acid metabolism and immune suppression through the JAK/STAT3 signaling axis. Inhibition of CSF1R reduced STAT3 activation and target gene expression, which was rescued by Colivelin. Combined treatment with LNCs@CSF1R siRNA and anti-PD-1 significantly slowed tumor growth and reduced MDSC abundance within CRC tumors.
CONCLUSIONS: CSF1R via the JAK/STAT3 axis critically regulates MDSCs, particularly in fatty acid metabolism and immune suppression. Combined therapy with LNCs@CSF1R siRNA and anti-PD-1 enhances therapeutic efficacy in a murine CRC model, providing a strong foundation for future clinical applications.
方法:来自CRC和邻近正常组织的单细胞转录组测序数据鉴定了MDSC相关的差异表达基因。RNA-seq分析全面分析小鼠CRC肿瘤中的MDSC基因表达。LNCs@CSF1RsiRNA纳米载体有效靶向并抑制CSF1R。流式细胞术定量CSF1R抑制后MDSC表面标志物的变化。RNA-seq和途径富集分析揭示了CSF1R对MDSC代谢和信号传导的影响。使用Colivelin和代谢评估来验证CSF1R抑制对JAK/STAT3信号传导轴的影响。通过基于荧光的流式细胞术测量葡萄糖和脂肪酸摄取。LNCs@CSF1RsiRNA和抗PD-1的疗效,单独和联合,在具有广泛肿瘤切片分析的小鼠CRC模型中进行评估。
结果:CSF1R在MDSC介导的免疫抑制中起重要作用。LNCs@CSF1RsiRNA纳米载体有效靶向MDSCs并抑制CSF1R。CSF1R通过JAK/STAT3信号轴调节MDSC脂肪酸代谢和免疫抑制。抑制CSF1R降低了STAT3的激活和靶基因的表达,是Colivelin救的.用LNC@CSF1RsiRNA和抗PD-1联合治疗显著减缓肿瘤生长并降低CRC肿瘤内的MDSC丰度。
结论:CSF1R通过JAK/STAT3轴关键调节MDSCs,特别是脂肪酸代谢和免疫抑制。LNCs@CSF1RsiRNA和抗PD-1联合治疗可增强小鼠CRC模型的疗效,为未来的临床应用奠定了坚实的基础。