Fig 1: Calcium signaling links stemness and tumorigenicity to the transforming phenotype of epithelial UCAPe cells. (a) cDNA microarray analysis showing that stemness and calcium signaling regulators were upregulated in UCAPe cells. See Supplemental Tables 2 and 3 for references on selected genes and their links to stemness and calcium signaling. (b) Surface immunofluorescence (IF) FACS showing that surface c-Kit ligand (SCF/KL) but not surface c-Kit discriminated UCAPe cells from mesenchymal cells (n = 3). (c) Western blotting (WB) showing that constitutive caspase-3 activation and generation of Nanog-D (cleaved fragment related to cellular differentiation) and Nanog-S (cleaved fragment related to sphere formation) discriminated UCAPe cells from mesenchymal cells (top panel), whereas Oct4 and Sox-2 were not expressed in any of the three cell lines (bottom panel). (d) Constitutive caspase-3 activation did not lead to DNA fragmentation evaluated by PI-FACS at 24 hours (n = 3). (e) Only UCAPe cells were able to transform in response to calcium signaling inhibition by verapamil plus dasatinib (n = 3). (f,g) CD24 but not ABCB1 cell surface expression as evaluated by surface IF-FACS marked transforming UCAPe cells (n = 3).