Epithelial-mesenchymal transition - activating transcription factors - multifunctional regulators in cancer

Figure 1 Schematic illustration of embryonic signaling pathways mediating epithelial-to-mesenchymal transition. Wnt, Notch, hedgehog, transforming growth factor β (TGFβ) along with other growth factors of cytokines transduce signal cascades, modulate the expression of epithelial-to-mesenchymal transition (EMT) regulators and allow them to translocate to nucleus. They act as epithelial repressors (EpR) and/or mesenchymal activators (MeA) and bind with E box of promoter regions of epithelial genes and mesenchymal genes respectively. These complexes have an inductive effect on EMT program by repressing epithelial genes and activating mesenchymal genes. IKK: IκB kinase; NF-κB: Nuclear factor kappa B; SMO: Smoothened; TNF-α: Tumor necrosis factor-α; PI3K: Phosphatidylinositol 3 kinase; GSK3β: Glycogen synthase kinase 3β; Fzd: Frizzled.