Snail-induced EMT promotes cancer stem cell-like properties in head and neck cancer cells.

Epithelial-mesenchymal transition (EMT) is a key process involved in the invasion and metastasis of cancer cells. Furthermore, EMT can induce a cancer stem cell (CSC)-like phenotype in a number of tumor types. We demonstrated that Snail is one of the master regulators that promotes EMT and mediates cancer cell migration and invasion in many types of malignancies including head and neck squamous cell carcinoma (HNSCC). In the present study, we investigated the role of Snail in inducing and maintaining CSC-like properties through EMT in HNSCC. We established HNSCC cell lines transfected with Snail. Stem cell markers were evaluated with real-time RT-PCR and western blot analysis. CSC properties were assessed using sphere formation and WST-8 assays as well as chemosensitivity and chick chorioallantoic membrane in vivo invasion assays. Introduction of Snail induced EMT properties in HNSCC cells. Moreover, Snail-induced EMT maintained the CSC-like phenotype, and enhanced sphere formation capability, chemoresistance and invasive ability. These data suggest that Snail could be one of the critical molecular targets for the development of therapeutic strategies for HNSCC.