Snail1-driven plasticity of epithelial and mesenchymal cells sustains cancer malignancy

The transcription factor Snail1 induces epithelial-to-mesenchymal transition (EMT) in tumor epithelial cells, a process associated with the emergence of sternness, invasion and cancer malignancy. Here, we review recent reports indicating that Snail1 also regulates mesenchymal plasticity and paracrine signaling and propose that Snail1 orchestrates the generation of cancer stem cells (CSCs) and cancer-associated fibroblasts (CAFs). Our view supports the current models for tumorigenesis that consider sternness and tumor microenvironment as retroactive actors for metastasis formation, revealing Snail1 as a regulator of these metastatic forces. This view offers new perspectives for understanding and targeting metastasis. (C) 2015 Elsevier B.V. All rights reserved.