Figure 5. Regulation of NF-kB signaling pathway after treatment of bortezomib. Western blot analysis of the NF-κB signaling pathway in the absence A or presence B of TGF-β1. Bortezomib downregulated nuclear factor kappa B (NF-κB)/phospho-NF-κB expression and upregulated nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor, alpha (IκBα) regardless of the presence of human transforming growth factor (TGF)-β1. C, D: Immunocytochemical staining at 60 min after the treatment with bortezomib yielded results similar to those for the western blot analysis.