Therefore, scientific research focusing on molecular pathways that promote intrahepatic/extrahepatic metastases via vascular invasion and HCC cell motility EPZ 6438 is vital to further our understanding of these processes. In this issue of the Journal of Gastroenterology and Hepatology, Ogunwobi et al. show in a novel HCC cell line that epithelial–mesenchymal transition (EMT) is a molecular mechanism that might underpin vascular invasion

and the invasiveness of HCC.2 EMT is a cellular program where polarized epithelial cells lose epithelial characteristics and develop a mesenchymal phenotype. This process involves the dissolution of intercellular connections (E-cadherin), rearrangement of the cellular cytoskeleton, upregulation of matrix remodeling factors, excess extracellular matrix production, and migration of epithelial cells into adjacent stroma by freeing them of their basement membrane.3 This could be seen akin to the processes that neoplastic cells undergo during metastatic spread. To date, several oncogenic pathways have been shown to induce EMT: peptide growth factors, Src, Ras, Ets, integrin, Wnt/β-catenin, and Notch. Two transcription

factors in particular are related to EMT through their repression of E-cadherin; these bear the names Snail and Slug. In addition, the expression Ibrutinib mw of the transcription factor, Twist, might induce EMT via the expression of forkhead box protein C2. The process of EMT was first described in a chick model of primitive streak formation by Hay in 1995.4 Since then, it has been shown to be a reversible process (EMT/mesenchymal–epithelial transition), and of crucial importance in a number of areas of biology. These can be divided into three well-characterized subtypes: (i) type 1 EMT is not associated with organ fibrosis or an invasive phenotype, and has been shown to be important in embryo implantation,

embryogenesis, and organ development (this will not be discussed further); (ii) type 2 EMT is associated with inflammation; it can lead to organ destruction and to tissue regeneration, see more processes that are involved in the development of organ fibrosis; and (iii) type 3 EMT is associated with an invasive phenotype, and it is this that might be important in HCC progression and metastasis.5 Here, Ogunwobi et al. show that EMT can be induced in a novel HCC cell line using epidermal growth factor (EGF), hepatocyte growth factor (HGF), basic fibroblast growth factor (bFGF), and transforming growth factor (TGF) β-1.2 They demonstrate EMT by confirming the loss of E-cadherin, albumin, and α1-anti-trypsin (AAT) (markers of the epithelial phenotype), and by verifying mesenchymal morphology through the cellular protein expression of vimentin, fibronectin, and collagen 1.