Metabolism and action of proteasome inhibitors in primary human hepatocytes.

ABSTRACT: Proteasome inhibitors are important tools for studying the roles of the proteasome in cellular processes. In this study, we observed that the proteasome inhibitors N-benzoyloxycarbonyl (Z)-Leu-Leu-leucinal (MG132), epoxomicin, and lactacystin were ineffective and bortezomib was completely effective in inhibiting cytokine-stimulated nitric oxide production in primary cultures of human hepatocytes that had been treated with the cytochrome P450 inducer phenobarbital. The inefficacy of MG132 was due to its metabolism by CYP3A enzymes, as deduced from its rapid, ketoconazole-sensitive clearance by pooled human liver microsomes and cultured hepatocytes. The efficacy of MG132 was increased by inclusion of ketoconazole in the hepatocyte incubations and decreased by prior treatment of the cultures

SUBMITTER: Lee CM 

PROVIDER: S-EPMC2993455 | biostudies-literature | 2010 Dec

REPOSITORIES: biostudies-literature