Figure 1

Schematic of local cancer recurrence in a reversible HER2/neu mouse model. Inactivation of HER2/neu expression results in the regression of breast tumors. Both epigenetic selection and a cocktail of extracellular signals can establish a population of Snail expressing cells allowing epithelial-to-mesenchymal transition and survival, eventually leading to mesenchymal recurrences. BMP, bone morphogenetic protein; EGF(-R), epidermal growth factor (-receptor); FGF(-R), fibroblast growth factor (-receptor); MMP, matrix metalloproteinase; PTC, patched; SCF, stem cell factor; Shh, sonic hedgehog; Smo, smoothened; TGF-β(-R), transforming growth factor beta (-receptor); WNT, member of the Wnt family of peptide ligands.