Fig. 4

Heatmaps and hierarchical clustering trees of ampullary cancer cell lines and tumors. Relative expression values of EMT (ZEB1, CDH1) and subtype marker genes (KRT7, KRT20, CDX2) were calculated by linear scaling, with maximum expression in cell lines/tumors defined as 100 % and subjected to hierarchical clustering (HCL). a HCL tree of the cell lines discloses an mesenchymal-like (MES) and a differentiated (D) cluster of cell lines. MES cells show weak or no expression of subtype marker genes but strong ZEB1 and low E-Cadherin (CDH1) expression. One differentiated cell line displays pancreatobiliary-like (SNU478, orange), the other an intestinal-like marker gene expression pattern (SNU869, blue). b HCL tree of tumors and cell lines results in separation of an intestinal (INT), pancreatobiliary (PB) and atypical (AT) cluster. The cell lines are found separated to the PB and INT clusters. For further details see text. Abbreviations: EMT epithelial-mesenchymal transition, ZEB1 zinc finger E-box binding homeobox 1, CDH1 Cadherin 1 = E-Cadherin, KRT Cytokeratin, CDX2 Caudal type homeobox 2, POOR poorly differentiated