(A) HPHs were treated with vehicle (0.1 % DMSO), PB (1 mM) or CITCO (2 µM) in the presence and absence of the irreversible proteasome inhibitor Lac. Total RNA, extracted after 24 h treatment, was subjected to real-time PCR analysis. Significantly different from DMSO and Lac (*), PB (#) or CITCO (+ +), P < 0.05. (B and C) In separate experiments, HPHs were infected with adenoviral-YFP-hCAR vectors, and then treated with vehicle control (0.1 % DMSO), 5 µM Lac alone, 1 mM PB or co-treatment with 5 µM Lac. Following 24 h treatment, the localization of hCAR-expressed cells was visualized with fluorescence microscopy.