Figure 3

Drivers and mediators of epithelial-mesenchymal transition (EMT). Early stage tumor cells maintain epithelial properties similar to the neighboring normal epithelium. The accidental overexpression of master regulators of EMT, such as the transcription factors Twist, Snail, and SIP1, in cancer cells leads to dramatic changes in gene expression profiles and cellular behavior. Twist, Snail, and SIP1 repress the expression of E-cadherin via E boxes in its promoter and trigger expression of an entire EMT transcriptional program through as yet unknown mechanisms. Several pathways are known to regulate Twist, Snail, and SIP1 expression in tumor cells while others (shown in parentheses) do so at least in developmental contexts. (Adapted from [21].)