Spatial multi omic profiling maps hypoxia-driven pro-fibrotic SPP1+ macrophages underpinning immune escape and TACE resistance in hepatocellular carcinoma.

BACKGROUND

To elucidate the cellular and molecular mechanisms underlying therapeutic resistance (refractoriness) following transarterial chemoembolization (TACE) in hepatocellular carcinoma (HCC) by comprehensively characterizing the post-treatment tumor microenvironment (TME).

METHODS

We employed an integrative spatial multi-omics strategy, combining bulk and single-cell RNA sequencing, subcellular-resolution spatial transcriptomics, and spatial proteomics on tissues from TACE-treated and treatment-naïve HCC patients. Public datasets were used for prognostic and predictive validation, and key findings were confirmed with multiplex immunofluorescence and in vitro experiments.

RESULTS

TACE induced a profoundly hypoxic TME, which drove the selective enrichment of a pro-fibrotic tumor-associated macrophage (TAM) population characterized by high SPP1 expression (SPP1 + TAMs). Spatial mapping demonstrated that these SPP1 + TAMs localize to hypoxic tumor cores, where they remodel the extracellular matrix by producing fibronectin (FN1), establish fibrotic niches, and restrict T-cell activation, thereby orchestrating an immune-excluded microenvironment. The abundance of this macrophage subtype was a robust predictor of TACE resistance.

CONCLUSIONS

TACE-induced hypoxia promotes a macrophage-driven fibrotic program that is a key determinant of immune evasion and treatment failure in HCC. Targeting this SPP1 + TAM-mediated fibrotic niche presents a potential therapeutic strategy to overcome TACE resistance and improve clinical outcomes.