TWIST expression in hypopharyngeal cancer and the mechanism of TWIST-induced promotion of metastasis.

The transcription factor TWIST is an important factor in regulating epithelial-mesenchymal transition (EMT) and tumor metastasis. To explore the functions of TWIST in hypopharyngeal cancer, we investigated if overexpression of TWIST has an effect on FaDu cell morphology, and if alteration of TWIST has an effect on E-cadherin, N-cadherin, c-fos, MMP-9, as well as in cell migration, and the invasion ability of FaDu cells. Moreover, we also studied the relationship between TWIST overexpression and clinicopathological characteristics in hypopharyngeal cancer tissue samples by immunohistochemical assays. The results showed that overexpression of TWIST-induced morphological changes, such as occurrence of EMT. TWIST overexpression also increased cell migration and invasion ability, accompanied by an alteration of E-cadherin, N-cadherin, c-fos and MMP-9 expression. Furthermore, immunohistochemical assays showed that TWIST overexpression was related with tumor differentiation (P=0.038), tumor size (P=0.048) and lymph node metastasis (P=0.044). The data presented reveal that overexpression of TWIST plays a significant role in the metastasis of hypopharyngeal tumors, and alteration of TWIST has an effect on the EMT, c-fos and MMP-9 expression in FaDu cells. We conclude that TWIST promotes hypopharyngeal carcinoma metastasis, and the TWIST/c-fos/MMP-9 signaling pathway may play an important role in the metastasis of FaDu cells.