HAS1(high) cancer associated fibroblasts located at the tumor invasion front zone promote oral squamous cell carcinoma invasion via ECM remodeling.

BACKGROUND: Although tumor cell heterogeneity between the tumor center (TC) and invasion front (IF) of oral squamous cell carcinoma (OSCC) is well documented, the morphological, molecular, and functional characteristics of cancer-associated fibroblasts (CAFs) in these regions remain poorly understood. METHODS: We examined hematoxylin and eosin (H&E)-stained OSCC sections to assess CAF morphology and correlation with patient prognosis. We then isolated paired CAFs from the tumor center (CAF(TC)) and invasion front (CAF(IF)) of four OSCC patients and compared their ECM-remodeling activity and pro-tumorigenic effects on OSCC cells. Furthermore, RNA sequencing identified differentially expressed genes between CAF(TC) and CAF(IF). Finally, based on RNA-seq findings, we knocked down hyaluronan synthase 1 (HAS1) in CAF(IF) to evaluate its role in extracellular matrix (ECM) remodeling and tumor invasion. RESULTS: Compared to CAF(TC), CAF(IF) exhibited a plump cell morphology and were associated with shorter disease-free survival. Functionally, CAF(IF) showed higher ECM-remodeling activity and more effective ability for promoting OSCC invasion and lymph node metastasis than CAF(TC). RNA-seq identified HAS1 was significantly upregulated in CAF(IF), promoting hyaluronic acid (HA) production and ECM remodeling. HAS1 knockdown in CAF(IF) diminished ECM remodeling and attenuated the ability of CAF(IF) to promoting OSCC invasion. CONCLUSION: CAF(IF) with plump cell morphology showed pro-invasive abilities, driven in part by HAS1 overexpression and ECM remodeling, suggesting that targeting HAS1-driven ECM remodeling could be a promising therapeutic strategy.