Cytochrome P450 induction response in tethered spheroids as a three-dimensional human hepatocyte in vitro model.

Cytochrome P450 (CYP) induction is a key risk factor of clinical drug-drug interactions that has to be mitigated in the early phases of drug discovery. Three-dimensional (3D) cultures of hepatocytes in vitro have recently emerged as a potentially better platform to recapitulate the in vivo liver structure and to maintain long-term hepatic functions as compared with conven- tional two-dimensional (2D) monolayer cultures. However, the majority of published studies on 3D hepatocyte models use rat hepatocytesandtheresponsetoCYPinducersbetweenrodentsandhumansisdistinct.Inthepresentstudy,weconstructedteth- ered spheroids on RGD/galactose-conjugated membranes as an in vitro 3D model using cryopreserved human hepatocytes. CYP3A4mRNAexpressioninthetetheredspheroidswasinducedtoasignificantlygreaterextentthanthoseinthecollagensand- wich cultures, indicating the transcriptional regulation was more sensitive to the CYP inducers in the 3D model. Induction of CYP1A2, CYP2B6 and CYP3A4 activities in the tethered spheroids were comparable to, if not higher than that observed in the collagen sandwich cultures. The membrane-based model is readily integrated into multi-well plates for higher-throughput drug testing applications, which might be an alternative model to screen the CYP induction potential in vitro with more physiological relevance. Copyright © 2015 John Wiley & Sons, Ltd. Additional supporting information may be found in the online version of this article at the publisher's web site.