(A) MCF-7, MDA-231, and CA1a breast cancer cells stably transduced with the indicated lentiviral shRNA constructs and were grown to 70% confluence. EpCAM, phosphorylated RELA, IκBα, and actin expression were measured by immunoblot. Band density was analyzed by densitometric analysis using ImageJ software, arbitrarily assigning the band density of shSCR at 1.0. (B, C) CA1a breast cancer cells were stably transduced with the indicated lentiviral constructs, and then transiently transfected with an EpCAM cDNA construct resistant to RNA interference, and genetic constructs targeting NF-κB. Expression of EpCAM, RELA and IκBα was confirmed by immunoblot, and the impact on IL-8 promoter activity was measured using a dual-luciferase kit.