Loss of Gαq reshapes fibroblast traits and drives tumor-stroma remodeling in oral cancer progression

Head and neck squamous cell carcinoma (HNSCC) is an aggressive malignancy with limited therapeutic options and poor outcomes due to metastasis. A major driver of tumor progression is the tumor microenvironment, particularly cancer-associated fibroblasts (CAFs), which remodel the extracellular matrix and secrete pro-tumorigenic signals. Emerging evidence suggests that autophagy and vesicle trafficking pathways regulate these secretory functions, though their role in HNSCC remains unclear. Building on our discovery of Gαq as a central autophagy regulator, we investigated how its absence reshapes fibroblast behavior and modulates crosstalk with oral HNSCC cells. Our findings demonstrate that loss of Gαq reprograms murine fibroblasts into a CAF-like phenotype, in part through deregulated intracellular trafficking and increased ceramide accumulation. Gαq-deficient fibroblasts display increased collagen I deposition, ECM remodeling, and a shift toward secretory activity. Their exosomes, enriched in tumor-promoting growth factor receptors, suppress Caveolin 1 expression in tumor cells and induce an EMT-like phenotype that fuels aberrant HNSCC growth. In co-culture and in vivo, Gαq-silenced fibroblasts assemble into “railroad-track” structures that guide cancer cell migration and invasion. Reduced Gαq expression in human fibroblasts recapitulate these features underscoring a conserved mechanism of stromal activation. Overall, Gαq emerges as a key regulator of fibroblast plasticity and tumor-stroma interactions in HNSCC progression.