TMSB10 marks a malignant epithelial programme spatially associated with fibroblast–matrix niches in oral squamous cell carcinoma

Background Malignant epithelial states at the tumour-stroma interface may contribute to local invasion in oral squamous cell carcinoma (OSCC), but their reproducibility across patients and spatial relationship with fibroblast-matrix niches remain unclear. Methods Single-cell transcriptomes from 16 untreated OSCC samples were analysed to localise TMSB10 and derive a TMSB10-associated invasion-related programme (TIP) through within-patient comparisons of aneuploid epithelial cells. Frozen TIP scores were evaluated in independent single-cell and spatial cohorts. Spatial associations were tested using adjusted generalised additive models and random-effects meta-analysis. Survival associations were examined in GSE41613 and TCGA-HNSC, and TMSB10 was silenced in HN6 and HN30 cells. Results Among 89, 323 cells, TMSB10 was highly expressed in epithelial and endothelial compartments. TMSB10-high aneuploid epithelial cells exhibited 1, 569 differentially expressed genes and enrichment of 16 Hallmark pathways related to proliferation, oxidative metabolism, and epithelial plasticity. Frozen TIP scores showed concordant directions across patients and in GSE103322. TIP-core and TIP-anchor were positively associated with cancer-associated fibroblast/extracellular matrix (CAF/ECM) scores in all 18 spatial sections, with pooled effects of 0.1434 and 0.1456, respectively (both FDR = 0.000402); this association was reproduced in all four GSE220978 patients. In GSE41613, higher TMSB10 expression was associated with poorer overall and disease-specific survival after clinical adjustment, whereas TCGA-HNSC showed no consistent adjusted association. TMSB10 knockdown reduced CCK-8 signals, wound closure, and Transwell migration in both cell lines. Conclusion Within malignant epithelial cells, TMSB10 expression is associated with a reproducible, pEMT-related programme spatially associated with CAF/ECM-rich regions. Knockdown findings support the involvement of TMSB10 in OSCC cell growth and migration.