CD63-high macrophage-derived exosomal miR-6876-5p promotes hepatocellular carcinoma stemness via PTEN/Akt-mediated EMT pathway.

Objective: Accumulating evidence suggests that microRNAs derived from macrophage exosomes can regulate the stemness and progression of cancer. However, the interaction mechanisms between HCC cells and tumor-associated macrophages remain unclear.

Methods: Exosomes were extracted from control or CD63 overexpression macrophages and co-cultured with HCC cells. The stemness, proliferation, epithelial-mesenchymal transition, and in vivo tumorigenicity of HCC cells were assessed to determine the role of CD63-high macrophage-derived exosomal miR-6876-5p in HCC. The binding relationship between miR-6876-5p and the PTEN/Akt axis was also investigated.

Results: Elevated CD63 expression was associated with increased tumor-associated macrophage infiltration and poorer prognosis in HCC. CD63-high macrophage-derived exosomes enhanced HCC cell proliferation, stemness, and epithelial-mesenchymal transition. miR-6876-5p within these exosomes was identified as a key mediator, promoting HCC progression by targeting PTEN and activating the Akt signaling pathway. In vivo studies confirmed that CD63-high macrophage-derived exosomal miR-6876-5p accelerated tumor growth and enhanced stemness in HCC cells.

Conclusions: CD63-high macrophage-derived exosomes, particularly those enriched with miR-6876-5p, play a pivotal role in HCC progression by enhancing stemness and promoting epithelial-mesenchymal transition through the PTEN/Akt pathway. Targeting these exosomes and their microRNAs offers a promising therapeutic strategy forHCC.