Figure 2

EpCAM expression is associated with breast cancer invasion in vivo in a breast cancer xenograft model. (a and b) MDA-231 breast cancer cells were stably transduced with experimental (sh2) or control (scrambled control shRNA construct (SCR)) shRNA lentiviral constructs. One × 10⁷ MDA-231 cells were resuspended in matrigel (1:1 ratio by volume) and injected into nude mice (n = 10 per group). The right flank was injected with MDA-231(SCR) cells and the left flank was injected with MDA-231(sh2) cells. Tumor size was measured by electronic calipers every thre to five days. Photos at the time of sacrifice demonstrate tumor growth in the right flank but not in the left flank. (c) H&E evaluation of the tumor site demonstrates that MDA-231(SCR) cells were invading into the surrounding fat, while MDA-231(sh2) tumors were not invasive. (d) Specific ablation of EpCAM did not impact cell cycle/proliferation of MDA-231 cells when analyzed prior to tumor challenge. The percentage of cells in each stage of the cell cycle is indicated.