The role of ulcerative colitis-associated genes in the prognosis, immune cell infiltration, and immunotherapy efficacy of hepatocellular carcinoma
摘要
Genetic and epidemiological evidence suggests an association between ulcerative colitis (UC) and liver hepatocellular carcinoma (LIHC). However, whether UC-related transcriptional programs are linked to LIHC prognosis and tumor immune–metabolic phenotypes remains unclear.
MethodsUC-associated genes (UCGs) were identified by integrating three UC transcriptomic datasets (GSE75214, GSE92415, and GSE87466; 64 normal and 347 UC samples) using weighted gene co-expression network analysis and differential expression analysis. Diagnostic performance was evaluated using ROC analysis. Unsupervised clustering was performed to characterize UC heterogeneity. In TCGA-LIHC, we constructed a quantitative UC score by principal component analysis based on the prognosis-related genes derived from UC-score-associated differentially expressed genes, and assessed its associations with overall survival, immune infiltration (ssGSEA), and immunotherapy-related signatures (TIDE). Hub genes were further examined by single-cell annotation (GSE290925) and in vitro assays.
ResultsEighteen UCGs were identified in UC and stratified UC samples into three molecular clusters with distinct immune and metabolic features. In LIHC, a UC score derived from the UCG-related program robustly stratified overall survival in TCGA-LIHC and was externally validated in GSE76427, with the low-score group showing a more favorable prognosis and distinct immune-infiltration patterns. The UC score was also associated with differences in immunotherapy-related signatures, suggesting potential relevance to immune escape phenotypes. Among candidate hub genes, MEP1B and HSD3B2 showed high diagnostic accuracy for UC (pooled AUC = 0.936 and 0.923, respectively) and were downregulated in LIHC tumors. Single-cell analysis indicated relatively higher MEP1B expression in the B-cell compartment. In a UC-like in vitro inflammatory model, MEP1B and HSD3B2 downregulation was validated. The overexpression of MEP1B or HSD3B2 attenuated malignant behaviors of hepatocellular carcinoma cells.
ConclusionsThe UC score captures UC-related immune–metabolic programs that are associated with prognosis and tumor immune phenotypes in LIHC. MEP1B and HSD3B2 represent UC-linked markers with tumor-suppressive effects in HCC cell models, providing a rationale for further mechanistic studies on gut–liver axis-related comorbidity.