Programmed Death Ligand-1 in Melanoma and Extracellular Vesicles Promotes Local and Regional Immune Suppression through M2-like Macrophage Polarization.

ABSTRACT: Tumor-associated macrophages (TAMs) play dual roles (both pro- and antitumor) in tumor progression. TAMs induce programmed death ligand-1 (PD-L1) expression in cancer cells. However, the regulatory effects of PD-L1 in melanoma cells on TAM phenotypical switching remain underexplored. Herein, CD163 and MRC1 levels were significantly elevated in metastatic melanomas compared with those in primary melanomas, correlating with CD274 expression and predicted patient clinical outcomes. To study the mechanisms regulating M2-like polarization, PD-L1 was knocked out in both YUMM1.7 and B16-F10 melanoma cells. Knocking out PD-L1 (PD-L1^KO) in melanoma resulted in a decelerated in vivo growth rate, accompanied by a significantly increased M1/M2 ratio, more dendritic cells, and enhanced activ

SUBMITTER: Huang L 

PROVIDER: S-EPMC11773617 | biostudies-literature | 2025 Feb

REPOSITORIES: biostudies-literature