Emergence of the phosphoinositide 3-kinase-Akt-mammalian target of rapamycin axis in transforming growth factor-β-induced epithelial-mesenchymal transition.
During development and in pathological contexts such as fibrosis and cancer progression, epithelial cells can initiate a complex transcriptional reprogramming, accompanied by dramatic morphological changes, in a process named 'epithelial-mesenchymal transition' (EMT). In this transition, epithelial cells lose their epithelial characteristics to acquire mesenchymal properties and increased motile and invasive behavior. Transforming growth factor-β (TGF-β) has emerged as a major inducer of EMT through activation of downstream signaling pathways, including Smad and non-Smad signaling pathways. Among the non-Smad pathways, increasing evidence is emerging that the phosphoinositide 3-kinase-Akt-mammalian target of rapamycin axis plays a major role in TGF-β-induced EMT, notably through the regulation of translation and cell invasion. Pharmacological inhibitors of the phosphoinositide 3-kinase-Akt-mammalian target of rapamycin pathway may therefore represent an opportunity to selectively target essential aspects of TGF-β-induced EMT and provide an approach to prevent cancer cell dissemination toward metastasis, without the need to fully inactivate TGF-β signaling.
Department of Cell and Tissue Biology, Program in Cell Biology, University of California, San Francisco, CA 94143-0512, USA.
Samy
S
Lamouille
Rik
R
Derynck
D000818:Animals; D058750:Epithelial-Mesenchymal Transition / Q000187:drug effects*; D006801:Humans; D058539:Phosphatidylinositol 3-Kinase / Q000378:metabolism*; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism*; D058570:TOR Serine-Threonine Kinases / Q000378:metabolism*; D016212:Transforming Growth Factor beta / Q000494:pharmacology*
D016212:Transforming Growth Factor beta; D058539:Phosphatidylinositol 3-Kinase; D051057:Proto-Oncogene Proteins c-akt; D058570:TOR Serine-Threonine Kinases