METHODS: We analyzed the TCGA database to examine the association between VDR expression and immune cell infiltration in pancreatic adenocarcinoma (PAAD). Western blot, ELISA, ChIP, and dual-luciferase reporter assays were performed to determine the mechanism of VDR regulating CCL20. Migration assay and immunofluorescence were used to investigate the role of CCL20 in M2 macrophage polarization and recruitment. We employed multiplexed immunohistochemical staining and mouse models to validate the correlation of VDR on macrophages infiltration in PAAD. Flow cytometry analysis of M2/M1 ratio in subcutaneous graft tumors.
RESULTS: VDR is extensively expressed in PAAD, and patients with elevated VDR levels exhibited a significantly reduced overall survival. VDR expression in PAAD tissues was associated with increased M2 macrophages infiltration. PAAD cells overexpressing VDR promote macrophages polarization towards M2 phenotype and recruitment in vitro and vivo. Mechanistically, VDR binds to the CCL20 promoter and up-regulates its transcription. The effects of polarization and recruitment on macrophages can be rescued by blocking CCL20. Finally, the relationship between VDR and M2 macrophages infiltration was evaluated using clinical cohort and subcutaneous graft tumors. A positive correlation was demonstrated between VDR/CCL20/CD163 in PAAD tissues and mouse models.
CONCLUSIONS: High expression of VDR in PAAD promotes M2 macrophage polarization and recruitment through the secretion of CCL20, which activates tumor progression. This finding suggests that the combination of anti-macrophage therapy may improve the efficacy of VDR activation therapy in PAAD.
方法:我们分析了TCGA数据库,以检查胰腺癌(PAAD)中VDR表达与免疫细胞浸润之间的关联。蛋白质印迹,ELISA,ChIP,和双荧光素酶报告基因测定以确定VDR调节CCL20的机制。采用迁移实验和免疫荧光法研究CCL20在M2巨噬细胞极化和募集中的作用。我们采用多重免疫组织化学染色和小鼠模型来验证VDR对PAAD中巨噬细胞浸润的相关性。皮下移植瘤中M2/M1比值的流式细胞术分析。
结果:VDR在PAAD中广泛表达,VDR水平升高的患者总生存率显著降低.PAAD组织中的VDR表达与M2巨噬细胞浸润增加有关。过表达VDR的PAAD细胞在体外和体内促进巨噬细胞向M2表型和募集的极化。机械上,VDR结合CCL20启动子并上调其转录。可以通过阻断CCL20来挽救极化和募集对巨噬细胞的影响。最后,使用临床队列和皮下移植瘤评估了VDR和M2巨噬细胞浸润之间的关系.在PAAD组织和小鼠模型中,VDR/CCL20/CD163之间呈正相关。
结论:PAAD中VDR的高表达通过CCL20的分泌促进M2巨噬细胞的极化和募集,从而激活肿瘤的进展。这一发现表明抗巨噬细胞疗法的组合可以提高PAAD中VDR活化疗法的功效。