Loss of Ezh2 promotes M2-like macrophage polarization in hepatocellular carcinoma

Tumor-associated macrophages (TAMs) promote tumor progression and metastasis. Ezh2, the catalytic component of Polycomb repressive complex 2, mediates transcriptional silencing through H3K27me3 deposition. Here, we demonstrate that Ezh2 deficiency in bone marrow-derived macrophages (BMDMs) enhances M2-like polarization upon exposure to conditioned media from Hepa1-6 hepatocellular carcinoma cells. RNA-seq analysis revealed stronger induction of M2-associated genes in conditioned Ezh2 knockout BMDMs compared with wild-type controls, along with enrichment of glycolysis and JAK/STAT signaling pathways. ATAC-seq showed increased chromatin accessibility at promoters of pyruvate metabolism-related genes and reduced H3K27me3 enrichment in Ezh2-deficient macrophages. Metabolic flux analysis confirmed elevated glycolytic activity in Ezh2 knockout BMDMs. Furthermore, phosphorylated STAT3 levels positively correlated with the M2 marker ArgI, and both were further increased in the absence of Ezh2. These findings suggest that Ezh2 restrains glycolytic reprogramming and limits hepatocellular carcinoma-induced M2-like macrophage polarization.