TRIM24 (Tripartite Motif Containing 24) is a recently identified oncogene overexpressed in various cancers. However, the molecular mechanism of TRIM24 in the progression of head and neck squamous cell carcinoma (HNSCC) remains ambiguous. In the present study, we analyzed the expression pattern of TRIM24 in 100 HNSCC tissues and found that TRIM24 was overexpressed in 43/100 HNSCC cases. Significant association was found between TRIM24 overexpression and tumor-node-metastasis (TNM) stage (p=0.0034) and T stage (p=0.0048). Furthermore, we overexpressed and knocked down TRIM24 in Detroit 562 and FaDu cell lines, respectively. TRIM24 overexpression promoted proliferation, colony formation, and invasion, while TRIM24 depletion inhibited proliferation, colony formation, and invasion. Further studies showed that TRIM24 facilitated cell cycle transition and upregulated cyclin D1 and p-Rb. In addition, we found that GLUT3, a key protein involved in regulating glucose metabolism, was altered in HNSCC cells overexpressing TRIM24. We demonstrated that TRIM24 overexpression increased glucose uptake ATP production. Overexpression of TRIM24 increases cell sensitivity to glucose deprivation in Detroit cells. Depleting TRIM24 in FaDu cells demonstrated the opposite results. We also showed that TRIM24 could bind to the promoter region of cyclin D1. In conclusion, TRIM24 is upregulated in HNSCC and promotes HNSCC cell growth and invasion through modulation of cell cycle, glucose metabolism, and GLUT3, making TRIM24 a potential oncoprotein in HNSCC.
Cyclin-D1-gene amplification is a more potent prognostic factor than its protein over-expression in human head-and-neck squamous-cell carcinoma
