Cancer Immunol Res. 2025 Nov 13. doi: 10.1158/2326-6066.CIR-24-1255. Online ahead of print.

ABSTRACT

Tumor-associated macrophages (TAMs) play crucial and important role in cancer dynamics by affecting homeostasis, immunosuppression, and angiogenesis within the tumor microenvironment. Using single-cell transcriptomics, we constructed a comprehensive atlas of myeloid cell populations across healthy and pan-cancer tissues that revealed heterogeneity. Our analysis suggested that TAMs may arise from two distinct origins: C1QC+ TAMs, which likely are derived from resident tissue macrophages, SPP1+ TAMs and ISG15+ TAMs, which appear to originate from circulating monocytes. Regarding immature myeloid-derived suppressor cells (MDSCs), we highlighted THBS1+ MDSCs and their descendants, SPP1+ TAMs, as key contributors to tumor progression, immunosuppression, and angiogenesis. We proposed a dichotomous model for TAMs, in which C1QC+ TAMs are associated with better patient outcomes, whereas the THBS1+ MDSCs – SPP1+ TAMs lineage correlates with poorer survival and unfavorable response to immunotherapy. This study offers insight into the complex interactions among monocyte-macrophage subtypes and sheds light on TAM heterogeneity and its implications for cancer progression and therapeutic strategies.

PMID:41231218 | DOI:10.1158/2326-6066.CIR-24-1255