Multi-omics characterization of CAF-related transcriptional programs reveals a smoking-context-informed 11-gene prognostic signature in HNSCC
摘要
Tobacco exposure contributes to the development and progression of head and neck squamous cell carcinoma (HNSCC) through genomic damage and alterations in the tumor microenvironment. Cancer-associated fibroblasts (CAFs) are important stromal components of the tumor microenvironment, but the relationships among smoking background, CAF-related transcriptional programs, and clinical outcomes in HNSCC remain incompletely understood. We aimed to characterize CAF-related transcriptional programs in HNSCC and evaluate their prognostic relevance in the context of smoking status.
MethodsWe integrated scRNA-seq data with bulk RNA-seq analyses from TCGA-HNSC, in which smoking-background differential expression analyses were used for candidate-gene discovery. Using hdWGCNA, we identified CAF-associated gene modules and constructed a smoking-related CAF 11-gene (SRCAF-11) signature using machine-learning approaches. We evaluated the signature using external cohorts, immune deconvolution analyses, and SHAP-based feature interpretation. We also modulated INHBA expression in HNSCC cell lines to assess its effects on proliferation, migration, invasion, and EMT-related features.
ResultsWe identified five transcriptionally distinct CAF subtypes. Matrix-remodeling CAFs (matCAFs) showed extracellular matrix-related features, and higher MuSiC-inferred matCAF relative abundance was associated with poorer survival. Smoker and non-smoker tumors did not differ significantly in MuSiC-inferred CAF-subtype proportions, whereas smoker tumors showed enrichment of EMT- and extracellular matrix-remodeling-related transcriptional programs. The SRCAF-11 signature stratified overall survival across retrospective HNSCC cohorts. INHBA emerged as a major contributor to the model and was preferentially expressed in matCAFs. High INHBA expression was associated with lower inferred immune activity and increased EMT-related transcriptional features in malignant epithelial cells. In vitro, modulation of INHBA expression altered HNSCC cell proliferation, migration, invasion, epithelial and mesenchymal marker expression, and E-cadherin localization.
ConclusionThe SRCAF-11 signature showed prognostic stratification capability across retrospective HNSCC cohorts. INHBA was identified as a major model feature associated with p-EMT-related transcriptional characteristics. These findings support a context-dependent association between smoking status, CAF-related transcriptional programs, and aggressive tumor phenotypes in HNSCC. Further mechanistic and spatial validation is required.