3D Spheroid Primary Human Hepatocytes for Prediction of Cytochrome P450 and Drug Transporter Induction

Primary human hepatocytes (PHHs) have been the gold standard in vitro model for the human liver and are crucial to predict hepatic drug-drug interactions. The aim of this work was to assess the utility of 3D spheroid PHHs to study induction of important cytochrome P450 (CYP) enzymes and drug transporters. The 3D spheroid PHHs from three different donors were treated for 4 days with rifampicin, dicloxacillin, flucloxacillin, phenobarbital, carbamazepine, efavirenz, omeprazole, or beta-naphthoflavone. Induction of CYP1A1, CYP1A2, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, and CYP3A4, and transporters P-glycoprotein (P-gp)/ABCB1, multidrug resistance-associated protein 2 (MRP2)/ABCC2, ABCG2, organic cation transporter 1 (OCT1)/SLC22A1, SLC22A7, SLCO1B1, and SLCO1B3 were evaluated at mRNA and protein levels. Enzyme activity of CYP3A4, CYP2B6, CYP2C19, and CYP2D6 were also assessed. Induction of CYP3A4 protein and mRNA correlated well for all donors and compounds and had a maximal induction of five- to sixfold for rifampicin, which closely correlates to induction observed in clinical studies. Rifampicin induced the mRNA of CYP2B6 and CYP2C8 by 9- and 12-fold, whereas the protein levels of these CYPs reached 2- and 3-fold induction, respectively. Rifampicin induced CYP2C9 protein by 1.4-fold, whereas the induction of CYP2C9 mRNA was over 2-fold in all donors. Rifampicin induced ABCB1, ABCC2, and ABCG2 by 2-fold. In conclusion, 3D spheroid PHHs is a valid model to investigate mRNA and protein induction of hepatic drug-metabolizing enzymes and transporters, and this model provides a solid basis to study induction of CYPs and transporters, which translates to clinical relevance.