The high expression of TC1 (C8orf4) was correlated with the expression of β-catenin and cyclin D1 and the progression of squamous cell carcinomas of the tongue.

Thyroid cancer 1 (TC1, C8orf4) plays important roles in many signaling pathways, such as Wnt/β-catenin signaling pathway, and is involved in the development of many cancers. The objective of this study was to examine the expression of TC1 and investigate the associations among TC1, β-catenin, Chibby, cyclin D1, and the clinicopathological factors of oral tongue squamous cell carcinomas (OTSCCs). The expressions of TC1, β-catenin, Chibby, and cyclin D1 were examined in 109 cases of OTSCCs using immunohistochemistry. The expression of TC1 was observed in all cases of OTSCCs but was negative or weak in normal squamous epithelial tissues of tongue. The high expression of TC1 was correlated with the advanced TNM stage (P = 0.042), the abnormal expression of β-catenin (correlation coefficient = 0.314, P = 0.001) and the expression of cyclin D1 (correlation coefficient = 0.274, P = 0.006) in OTSCCs. But we did not find any associations between TC1 and Chibby. The abnormal expression of β-catenin was correlated with the poor differentiation (P = 0.035), advanced TNM stage (P = 0.048) and the expression of cyclin D1 (correlation coefficient = 0.422, P < 0.001). In conclusion, the high expression of TC1 was common in OTSCCs and correlated with the expression of β-catenin and cyclin D1 and the progression of OTSCCs. The high expression level of TC1 might promote the progression of OTSCCs by enhancing the activity of Wnt signaling pathway.