Exploration of the roles of CAFs in melanoma based on single-cell transcriptomics and spatial transcriptomics

<h4>Background</h4>Cancer-associated fibroblasts (CAFs) are increasingly recognized as critical contributors to the limited efficacy of immunotherapy, particularly through the establishment of immune-excluded tumor microenvironments. However, the functional heterogeneity and spatial ecological roles of CAFs in melanoma remain poorly characterized.<h4>Methods</h4>We integrated single-cell RNA sequencing, spatial transcriptomics, and bulk RNA-seq data to systematically dissect CAF molecular programs in melanoma using weighted gene co-expression network analysis (WGCNA). Spatial distribution, CellChat, and ligand-receptor interaction analyses were applied to construct CAF-centered immune exclusion networks. A functional scoring model (riskScore) based on the CAF-M1 module was developed to evaluate clinical relevance.<h4>Results</h4>CAF was spatially co-localized with endothelial cells, and engaged in strong crosstalk with multiple immune cell types via pathways such as COLLAGEN-integrin and THBS1-CD47. The derived riskScore model demonstrated robust prognostic value across TCGA-SKCM cohort.<h4>Conclusion</h4>Through spatial aggregation and multifaceted immune signaling, CAF constructs a multilayered immune-exclusion network in melanoma, linking stromal remodeling to immune evasion. These findings offer novel insights into CAF-driven immune resistance and may inform future stratified immunotherapeutic strategies.