Paracrine regulation of neural crest EMT by placodal MMP28

Epithelial-Mesenchymal Transition (EMT) is an early event in cell dissemination from epithelial tissues. EMT endows cells with migratory, and sometimes invasive, capabilities and is thus a key process in embryo morphogenesis and cancer progression. So far, Matrix Metalloproteinases (MMPs) have not been considered as key players in EMT but rather studied for their role in matrix remodelling in later events such as cell migrationper se. Here we usedXenopusneural crest cells to assess the role of MMP28 in EMT and migrationin vivo. We provide strong evidence indicating that MMP28 produced by neighbouring placode cells is imported in the nucleus of neural crest cells for EMT and migration to occur.