biostudies-literatureUnknown9(1)Cai YPolymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs) are crucial mediators of tumor-induced immunosuppression, while their heterogeneity and spatial dynamics across malignancies remain poorly understood. By integrating single-cell RNA sequencing data from 576 samples across 19 cancer types and spatial transcriptomics data from three distinct malignancies, we identified a PMN-MDSC population. This cell population demonstrated characteristic upregulation of immunosuppressive genes and was associated with poor prognosis across multiple cancer cohorts. Notably, TREM1 was highly expressed in PMN-MDSCs and may mediate immunosuppressive processes. Multiplex immunofluorescence demonstrated that TREM1⁺ PMN-MDSCs exhibited significantly higher distribution in tumor regions compaCommunications biology75https://www.ebi.ac.uk/biostudies/studies/S-EPMC12820143biostudies-literaturePan-cancer analysis reveals TREM1<sup>+</sup> PMN-MDSCs as critical regulators of immune suppression and tumor microenvironment remodeling.PMC12820143Li HZheng XHe JYang MTeng HTang HLiu YZou ZWang PLi SLuo KHuang XCai YFeng WLiao SWu WfalsePan-cancer analysis reveals TREM1<sup>+</sup> PMN-MDSCs as critical regulators of immune suppression and tumor microenvironment remodeling.Polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs) are crucial mediators of tumor-induced immunosuppression, while their heterogeneity and spatial dynamics across malignancies remain poorly understood. By integrating single-cell RNA sequencing data from 576 samples across 19 cancer types and spatial transcriptomics data from three distinct malignancies, we identified a PMN-MDSC population. This cell population demonstrated characteristic upregulation of immunosuppressive genes and was associated with poor prognosis across multiple cancer cohorts. Notably, TREM1 was highly expressed in PMN-MDSCs and may mediate immunosuppressive processes. Multiplex immunofluorescence demonstrated that TREM1⁺ PMN-MDSCs exhibited significantly higher distribution in tumor regions compa2025-01-01T00:00:00Z2025 Dec2026-06-06T18:13:13.236Z2026-06-04T03:12:12.776ZS-EPMC128201434141373410.1038/s42003-025-09342-8