Upregulation of far upstream element-binding protein 1 (FUBP1) promotes tumor proliferation and unfavorable prognosis in tongue squamous cell carcinoma.

BACKGROUND: A well-known transcriptional regulator of the proto-oncogene c-Myc, far-upstream element (FUSE) binding protein 1 (FUBP1) has been demonstrated by previous work to be aberrantly expressed in lots of cancers and plays a critical role in tumor progression; however, its expression and function in tongue squamous cell carcinoma (TSCC) remains unclear. METHODS: Evaluations with immunohistochemistry, quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot were performed to assess FUBP1 expression. The correlations of FUBP1 expression levels with various clinicopathological factors were evaluated with univariate and multivariate analyses. In addition, the role of FUBP1 in TSCC proliferation was studied in TSCC cells by silencing FUBP1. The role of FUBP1 on proliferation and apoptosis was confirmed by cell counting Kit-8, colony formation, cell cycle, and cell apoptosis assays. RESULTS: Immunohistochemistry, qRT-PCR and Western blot results showed FUBP1 expression was higher in TSCC tissues in comparison with adjacent non-cancerous tissues (P <0.05), as well as in patients with advanced-stage disease or cervical lymph node metastasis (P<0.001). The 5-year survival rate was significantly lower in the group with high FUBP1 expression than in that with low FUBP1 expression (P=0.035). FUBP1 expression was also an independent predictor for overall survival in TSCC patients, and was closely related to poor prognosis. FUBP1 knockdown inhibited cancer cell proliferation, and induced cell cycle arrest and apoptosis. CONCLUSION: FUBP1 was overexpressed in TSCC, and correlated with TSCC cell proliferation and poor prognosis. FUBP1 appears to act as a potential oncogene in TSCC, and may be considered a novel biomarker for TSCC.