Spatial analysis identifies LAMTOR2 overexpression in hepatocellular carcinoma with vessels encapsulating tumor clusters.

BACKGROUND

Vessels encapsulating tumor clusters (VETC) is a distinct angiogenic pattern in hepatocellular carcinoma (HCC). While VETC-positive HCC is associated with poor prognosis, it demonstrates improved responses to vascular-targeted therapies. However, the molecular signatures that define VETC-positive HCC remain elusive. This study employed spatial transcriptomics and single-cell RNA sequencing to characterize the molecular landscape of VETC-positive HCC and identify candidate biomarkers.

METHODS

Using GeoMx Digital Spatial Profiling, we analyzed tumor and adjacent liver tissues from 24 HCC patients, focusing on VETC-positive, VETC-negative, or non-neoplastic liver regions. Differential gene expression and pathway enrichment analyses were performed. Candidate genes were further evaluated using immunohistochemistry, The Cancer Genome Atlas (TCGA) dataset, and single-cell RNA sequencing.

RESULTS

Spatial transcriptomic analysis identified 39 genes upregulated in VETC-positive regions, with enrichment of angiogenesis, WNT/β-catenin, Hedgehog, and p53 signaling, epithelial-mesenchymal transition, and fatty acid metabolism pathways, and suppression of immune-related pathways. Among these, LAMTOR2, DPP4, ZNHIT1, and MLXIPL were consistently upregulated in VETC-positive regions compared to both VETC-negative and normal liver regions. LAMTOR2 demonstrated tumor-specific localization in TCGA dataset. Immunohistochemistry confirmed that peripheral accentuation pattern of LAMTOR2 expression was restricted to tumor cells and strongly correlated with RNA expression and VETC positivity. Single-cell RNA sequencing further revealed LAMTOR2 upregulation in malignant hepatocytes, particularly within VETC-high subpopulations enriched for lipid degradation, fatty acid oxidation, and detoxification pathways.

CONCLUSION

VETC-positive HCC exhibits a distinct transcriptomic and metabolic profile. LAMTOR2, which is consistently upregulated in VETC-positive HCCs, may contribute to angiogenic and metabolic reprogramming, offering potential implications for therapeutic stratification in HCC.