Chromogranin B promotes EMT-associated stem-like properties and chemoresistance in HNSCC

Epithelial–mesenchymal transition (EMT)-associated stemness and therapeutic resistance are major drivers of HNSCC progression; however, the upstream regulators coordinating these malignant programs remain incompletely understood. TCGA-HNSC, GEO, and single-cell RNA sequencing datasets were analyzed to evaluate CHGB expression, prognostic value, and its association with epithelial–mesenchymal transition (EMT). EMT scoring, gene set enrichment analysis, weighted gene co-expression network analysis, and Cox regression analyses were performed. Gain- and loss-of-function approaches, xenograft models, tumorsphere formation assays, cisplatin sensitivity assays, and rescue experiments were used to investigate the biological functions and molecular mechanisms of CHGB in HNSCC. CHGB was significantly upregulated in HNSCC tissues and associated with poor overall survival. Integrative analyses identified a strong association between CHGB expression and EMT-related transcriptional programs. Functionally, CHGB depletion inhibited proliferation, migration, cell-cycle progression, primary and secondary tumorsphere formation, cisplatin resistance in vitro, and tumor growth in vivo, whereas CHGB overexpression exerted opposite effects. Mechanistically, CHGB promoted EMT-associated stemness and chemoresistance by sustaining ZEB1 expression through PI3K/AKT signaling. ZEB1 restoration partially rescued the impaired self-renewal capacity and enhanced cisplatin sensitivity induced by CHGB knockdown, whereas ZEB1 silencing attenuated CHGB-driven malignant phenotypes. Single-cell transcriptomic analyses further confirmed that CHGB was enriched in malignant cells and positively associated with EMT and stemness programs. CHGB functions as a critical regulator of EMT-associated stemness and chemoresistance through the PI3K/AKT/ZEB1 axis and represents a potential prognostic biomarker and therapeutic target in HNSCC.