Expression and clinical significance of FOXE1 in papillary thyroid carcinoma

Papillary thyroid cancer (PTC) is the most common form of well-differentiated thyroid carcinoma. Although the incidence of PTC has been on the increase in China, the precise causes of the disease remain unknown and a prognostic index has yet to be identified. In the present study, quantitative real‑time PCR and western blot analysis were used to detect the mRNA and protein expression levels, respectively, of forkhead box E1 (FOXE1) in 30 PTC tissue specimens matched with adjacent non-tumor thyroid tissues. FOXE1 expression in 81 PTC paraffin-embedded blocks was also evaluated retrospectively by immunohistochemistry (IHC) and its correlation with the clinicopathological parameters of PTC patients was analyzed. Compared with adjacent non-tumor tissues, the mRNA expression levels of the FOXE1 gene in tumor tissues were significantly higher in 65% of PTC tissue specimens. The results from western blotting and IHC analysis were consistent with FOXE1 mRNA expression. Furthermore, the expression of FOXE1 was significantly correlated with the extra-capsular invasion of tumor cells, lymph node metastasis and tumor stage (P=0.048, P=0.036 and P=0.009, respectively). Thus, our results demonstrated that the expression of FOXE1 was significantly increased in PTC tumor tissues and correlated with clinical prognosis. Therefore, FOXE1 is a potential biomarker for PTC prognosis as well as a new therapeutic target.