[SNAI1 and SNAI2 - transcriptional master-regulators of epithelial-mesenchimal transition]

Epithelial-mesenchymal transition is a result of cellular epigenetic reprogramming. During this process differentiated epithelial cells lose specific markers of epithelial phenotype and gradually start displaying qualities of poorly differentiated mesenchymal cells, resistant to apoptosis and capable of local invasion. Despite their obvious importance for biology and medicine, many aspects of epithelial-mesenchymal transition, especially those related to its genetic regulation, remain poorly characterized. In this review we analyze molecular structure and mechanisms of regulation of two closely-related transcription factors SNAI1 and SNAI2, which play an important role in induction and progression of epithelial-mesenchymal transition during both normal development and carcinogenesis. Special attention is paid to the role of SNAI1 and SNAI2 and their active co-reeressors in initiation of epigenetic repression of epithelial differentiation marker genes.