Epithelial to mesenchymal transition in head and neck squamous cell carcinoma

Epithelial to mesenchymal transition (EMT) is a dynamic cellular process that is essential for the development of metastatic disease. During EMT, a tumor cell with epithelial characteristics transitions to a tumor cell with mesenchymal characteristics through modulation of cell polarity and adhesion. Two hallmark EMT proteins, E-Cadherin and Vimentin, are tightly controlled during EMT through multiple signal transduction pathways. Epidermal growth factor (EGF) and transforming growth factor beta (TGF beta) promote EMT by regulating a distinct set of transcription factors, including Snail and Twist. Snail, Twist, and Slug are integral to the induction of EMT through direct regulation of genes involved in cellular adhesion, migration, and invasion. This review highlights the current literature on EMT in HNSCC. Understanding the role of EMT will provide insight to the pathogenesis of disease progression and may lead to the development of novel anti-cancer therapeutics for metastatic HNSCC. (C) 2012 Elsevier Ltd. All rights reserved.