Involvement of TGFBI-TAGLN axis in cancer stem cell property of head and neck squamous cell carcinoma.

Head and neck squamous cell carcinoma (HNSCC) is a significant healthcare burden globally. Previous research using single-cell transcriptome analysis identified TGFBI as a crucial marker for the partial-epithelial-mesenchymal transition (partial-EMT) program. However, the precise role of TGFBI in HNSCC progression remains unclear. Therefore, our study aimed to clarify the impact of TGFBI on the malignant behavior of HNSCC cells. Through RNA-sequencing data from the TCGA database, we validated that increased TGFBI expression correlates with a higher occurrence of lymph node metastasis and unfavorable prognosis in HNSCC cases. Functional experiments demonstrated that TGFBI overexpression enhances the ability of sphere formation, indicating stem-cell-like properties. Conversely, TGFBI depletion reduces sphere formation and suppresses the expression of cancer stem cell (CSC) markers. RNA-sequencing analysis of TGFBI-overexpressing and control HNSCC cells revealed TAGLN as a downstream effector mediating TGFBI-induced sphere formation. Remarkably, TAGLN depletion abolished TGFBI-induced sphere formation, while its overexpression rescued the suppressed sphere formation caused by TGFBI depletion. Moreover, elevated TAGLN expression showed correlations with the expression of TGFBI and partial-EMT-related genes in HNSCC cases. In conclusion, our findings suggest that TGFBI may promote CSC properties through the upregulation of TAGLN. These novel insights shed light on the involvement of the TGFBI-TAGLN axis in HNSCC progression and hold implications for the development of targeted therapies.