Figure 1

EpCAM expression is associated with breast cancer invasion in vitro. Epithelial cell adhesion molecule (EpCAM) expression was specifically ablated in the breast cancer cell lines MDA-231 and CA1a by RNA interference and rescued, as indicated, by transient transfection with an EpCAM cDNA resistant to RNA interference. (a) Specific ablation of EpCAM by shRNA results in a significant decrease in EpCAM protein expression as measured by immunoblot. For each cell line, sh2 designates transduction with a lentiviral vector targeting the 3' untranslated region of EpCAM, while scrambled control shRNA construct (SCR) designates transduction with a lentiviral vector expressing a scrambled control shRNA sequence. (b) Invasion was measured using a matrigel transwell invasion assay. After 24 to 72 hours, cells invading through the matrigel membranes were fixed using 70% ethanol, stained with 0.1% crystal violet and photographed in four fields to cover the entire area. Error bars represent the standard error of three experiments performed in triplicate. (c and d) Rescue of EpCAM expression in MDA-231 cells by cDNA expression (RES), rescues protein expression (immunoblot) and invasion (matrigel transwell invasion assay).