Li A P, Maurel P, Gomez-Lechon M J, Cheng L C, Jurima-Romet M
In Vitro Technologies, Baltimore, MD, USA.
Chem Biol Interact. 1997 Nov 6;107(1-2):5-16. doi: 10.1016/s0009-2797(97)00070-7.
Cytochrome P450 (CYP) inhibition and induction are the key mechanisms in drug-drug interactions. Aside from clinical studies, primary human hepatocytes may represent the most appropriate experimental system for the evaluation of CYP induction in humans. A consensus of an international panel on the present status and future research directions in the application of primary human hepatocytes in the evaluation of CYP-induction is presented here. The following observations are concluded to be generally true: (1) Human hepatocytes isolated from both biopsy samples and transplantable livers are suitable for induction studies. (2) Hormonally-defined media can be used for the evaluation of CYP induction. (3) Isozyme-selective induction of CYP1A and 3A by known inducers are observed. (4) Reproducibility of induction could be improved by using hepatocytes plated as confluent cultures. (5) Induction could be observed for hepatocytes treated at 1-3 days after culturing. (6) Treatment duration of 2 days in general leads to near maximal induction. (7) In general, there is a good qualitative correlation between human hepatocyte results in vitro and clinical observations in vivo. (8) When the same inducers were evaluated in independent laboratories, similar data were generally observed. We conclude that primary human hepatocytes represent an appropriate model for mechanistic evaluation of CYP induction and as a screening tool for CYP induction potential of xenobiotics. A set of data acceptance criteria are proposed: (1) Positive response should be observed with concurrent positive control chemicals; (2) reproducible observation should be observed with multiple human donors; (3) for negative response, the doses used should not be cytotoxic; and (4) replicate treatment and/or multiple dose treatment should be performed to allow statistical analysis. Future studies should include the further development of on: (1) The inducibility of CYP isozymes other than CYP1A and 3A, and phase II enzymes; (2) further development of culturing condition to allow optimal gene expression; (3) evaluation of the involvement of nonparenchymal cells on CYP induction of parenchymal cells; (4) the and validation of quantitative approaches to extrapolate in vitro data to in vivo data; (5) evaluation of possible individual variations and potential genetic polymorphism in inducibility; (6) further definition of species differences in CYP induction; (7) development of a 'normal' human hepatocyte cell line for CYP induction studies; (8) improvement of cryopreservation procedure of human hepatocytes; (9) definition of the molecular mechanisms of CYP induction; and (10) evaluation of the induction of phase II metabolic pathways.
细胞色素P450（CYP）抑制和诱导是药物相互作用的关键机制。除临床研究外，原代人肝细胞可能是评估人体CYP诱导作用最合适的实验系统。本文介绍了一个国际专家小组关于原代人肝细胞在CYP诱导评估中的应用现状和未来研究方向的共识。得出以下观察结果普遍成立：（1）从活检样本和可移植肝脏中分离的人肝细胞适用于诱导研究。（2）激素定义的培养基可用于评估CYP诱导。（3）观察到已知诱导剂对CYP1A和3A的同工酶选择性诱导。（4）通过使用铺板为汇合培养的肝细胞可提高诱导的可重复性。（5）培养后1 - 3天处理的肝细胞可观察到诱导。（6）一般2天的处理时间可导致接近最大诱导。（7）总体而言，人肝细胞体外结果与体内临床观察之间存在良好的定性相关性。（8）在独立实验室评估相同诱导剂时，通常观察到相似的数据。我们得出结论，原代人肝细胞是评估CYP诱导作用机制的合适模型，也是评估外源性物质CYP诱导潜力的筛选工具。提出了一组数据接受标准：（1）应同时使用阳性对照化学品观察到阳性反应；（2）应在多个供体中观察到可重复的结果；（3）对于阴性反应，所用剂量不应具有细胞毒性；（4）应进行重复处理和/或多剂量处理以进行统计分析。未来的研究应包括进一步开展以下方面：（1）CYP1A和3A以外的CYP同工酶以及II相酶的诱导性；（2）进一步优化培养条件以实现最佳基因表达；（3）评估非实质细胞对实质细胞CYP诱导的影响；（4）定量方法的开发和验证，以将体外数据外推至体内数据；（5）评估诱导性方面可能的个体差异和潜在的基因多态性；（6）进一步明确CYP诱导中的物种差异；（7）开发用于CYP诱导研究的“正常”人肝细胞系；（8）改进人肝细胞的冷冻保存程序；（9）明确CYP诱导的分子机制；（10）评估II相代谢途径的诱导。
