Metabolic Profiling, Screening and Technologies Department, Siena Biotech S.p.A., Siena, Italy.
Drug Metab Dispos. 2012 Jan;40(1):104-10. doi: 10.1124/dmd.111.042309. Epub 2011 Oct 13.
Prediction of clearance in drug discovery currently relies on human primary hepatocytes, which can vary widely in drug-metabolizing enzyme activity. Potential alternative in vitro models include the HepaRG cell (from immortalized hepatoma cells), which in culture can express drug-metabolizing enzymes to an extent comparable to that of primary hepatocytes. Utility of the HepaRG cell will depend on robust performance, relative to that of primary hepatocytes, in routine high-throughput analysis. In this study, we compared intrinsic clearance (CL(int)) in the recently developed cryopreserved HepaRG cell system with CL(int) in human cryopreserved pooled hepatocytes and with CL(int) in vivo for 26 cytochrome P450 substrate drugs. There was quantitative agreement between CL(int) in HepaRG cells and human hepatocytes, which was linear throughout the range of CL(int) (1-2000 ml · min(-1) · kg(-1)) and not dependent on particular cytochrome P450 involvement. Prediction of CL(int) in HepaRG cells was on average within 2-fold of in vivo CL(int) (using the well stirred liver model), but average fold error was clearance-dependent with greater underprediction (up to at least 5-fold) for the more highly cleared drugs. Recent reporting of this phenomenon in human hepatocytes was therefore confirmed with the hepatocytes used in this study, and hence the HepaRG cell system appears to share an apparently general tendency of clearance-limited CL(int) in cell models. This study shows the cryopreserved HepaRG cell system to be quantitatively comparable to human hepatocytes for prediction of clearance of drug cytochrome P450 substrates and to represent a promising alternative in vitro tool.
目前，药物发现中的清除率预测依赖于人原代肝细胞，其药物代谢酶活性差异很大。潜在的替代体外模型包括 HepaRG 细胞（来自永生化肝癌细胞），其在培养中可以表达药物代谢酶，其程度可与原代肝细胞相媲美。HepaRG 细胞的效用将取决于其在常规高通量分析中的表现相对于原代肝细胞的稳健性。在这项研究中，我们比较了最近开发的冷冻保存 HepaRG 细胞系统的内在清除率（CL(int)）与人冷冻保存的混合原代肝细胞的 CL(int)以及 26 种细胞色素 P450 底物药物的体内 CL(int)。HepaRG 细胞和人肝细胞之间的 CL(int)存在定量一致性，在整个 CL(int)范围（1-2000 ml · min(-1) · kg(-1)）内呈线性，并且不依赖于特定细胞色素 P450 的参与。HepaRG 细胞中 CL(int)的预测平均与体内 CL(int)相差 2 倍（使用充分搅拌的肝脏模型），但平均倍误差与清除率有关，对于清除率较高的药物，预测误差更大（高达至少 5 倍）。因此，在这项研究中使用的肝细胞中证实了这种现象在人肝细胞中的最新报道，因此 HepaRG 细胞系统似乎具有细胞模型中有限清除率的 CL(int)的明显普遍趋势。这项研究表明，冷冻保存的 HepaRG 细胞系统在预测细胞色素 P450 药物底物的清除率方面与原代肝细胞具有定量可比性，是一种有前途的替代体外工具。
