Lycorine suppresses hepatocellular carcinoma via the reprogramming of myeloid and epithelial cells.

[BACKGROUND] Hepatocellular carcinoma (HCC) is an aggressive malignancy associated with an immunosuppressive tumor microenvironment (TME), which contributes to resistance to therapy. Lycorine, a natural alkaloid, has demonstrated anticancer potential, but its effects on HCC remain insufficiently explored.

[PURPOSE] This study aimed to systematically assess the impact of lycorine on HCC and elucidate its underlying mechanisms of action.

[STUDY DESIGN] In vivo orthotopic HCC mouse models were employed, incorporating high-dimensional single-cell techniques to comprehensively analyze the effects of lycorine on the TME.

[METHODS] Mice bearing orthotopic HCC tumors were treated with lycorine at doses of 10 or 20 mg/kg for 14 days. Tumor progression was assessed by measuring tumor weight. The immune landscape was examined using cytometry by time of flight (CyTOF), and cellular heterogeneity was evaluated via single-cell RNA sequencing (scRNA-seq). Cell-cell communication networks were reconstructed through CellChat analysis.

[RESULTS] Lycorine treatment significantly reduced tumor burden and modulated cytokine expression profiles. CyTOF analysis revealed that lycorine reprogrammed the immune landscape, enhancing macrophage and neutrophil infiltration while decreasing PD-L1 expression on neutrophils. scRNA-seq analysis indicated that lycorine regulated specific cell subpopulations, including malignant epithelial cells, Notch2 neutrophils, and Spp1 macrophages. Cell-cell communication analysis identified the regulation of the Mif-(Cd74+Cd44/Cxcr4) signaling axis as a key underlying mechanism.

[CONCLUSION] Lycorine remodels the HCC TME through coordinated actions on malignant epithelial cells and immune populations, notably neutrophil and macrophage subpopulations. These findings support the potential development of lycorine-based combination therapies for HCC.