Trans-chromosomic mice containing a human CYP3A cluster for prediction of xenobiotic metabolism in humans

• Published in: Human molecular genetics Vol. 22; no. 3; pp. 578 - 592
• Main Authors: Kazuki, Yasuhiro, Kobayashi, Kaoru, Aueviriyavit, Sasitorn, Oshima, Takeshi, Kuroiwa, Yoshimi, Tsukazaki, Yasuko, Senda, Naoto, Kawakami, Hiroki, Ohtsuki, Sumio, Abe, Satoshi, Takiguchi, Masato, Hoshiya, Hidetoshi, Kajitani, Naoyo, Takehara, Shoko, Kubo, Kinya, Terasaki, Tetsuya, Chiba, Kan, Tomizuka, Kazuma, Oshimura, Mitsuo
• Format: Journal Article
• Language: English
• Published: England 01-02-2013
• Subjects: Animals; Aryl Hydrocarbon Hydroxylases - genetics; Aryl Hydrocarbon Hydroxylases - metabolism; Blotting, Southern; Cell Line; CHO Cells; chromosome 7; Chromosomes, Artificial, Human; Chromosomes, Human, Pair 7; Cloning; Cloning, Molecular; Cricetinae; CYP3A gene; CYP3A7 protein; Cytochrome P-450 CYP3A - genetics; Cytochrome P-450 CYP3A - metabolism; Cytochrome P450; Dehydroepiandrosterone - metabolism; Drug development; Drugs; Enzymes; Female; Gene deletion; Gene expression; Gene Expression Regulation, Enzymologic; Genetic Loci; genomics; Human artificial chromosomes; Humans; Inactivation, Metabolic; Intestines - enzymology; Isoenzymes; Kinetics; Liver; Liver - enzymology; Metabolites; Mice; Mice, Inbred ICR; Mice, Transgenic; Microsomes - metabolism; Multigene Family; Small intestine; Transgenic mice; triazolam; Triazolam - pharmacokinetics; Xenobiotics - metabolism
• ISSN: 0964-6906; 1460-2083
• DOI: 10.1093/hmg/dds468

Human CYP3A is the most abundant P450 isozyme present in the human liver and small intestine, and metabolizes around 50% of medical drugs on the market. The human CYP3A subfamily comprises four members (CYP3A4, CYP3A5, CYP3A7, CYP3A43) encoded on human chromosome 7. However, transgenic mouse lines carrying the entire human CYP3A cluster have not been constructed because of limitations in conventional cloning techniques. Here, we show that the introduction of a human artificial chromosome (HAC) containing the entire genomic human CYP3A locus recapitulates tissue- and stage-specific expression of human CYP3A genes and xenobiotic metabolism in mice. About 700 kb of the entire CYP3A genomic segment was cloned into a HAC (CYP3A-HAC), and trans-chromosomic (Tc) mice carrying a single copy of germline-transmittable CYP3A-HAC were generated via a chromosome-engineering technique. The tissue- and stage-specific expression profiles of CYP3A genes were consistent with those seen in humans. We further generated mice carrying the CYP3A-HAC in the background homozygous for targeted deletion of most endogenous Cyp3a genes. In this mouse strain with 'fully humanized' CYP3A genes, the kinetics of triazolam metabolism, CYP3A-mediated mechanism-based inactivation effects and formation of fetal-specific metabolites of dehydroepiandrosterone observed in humans were well reproduced. Thus, these mice are likely to be valuable in evaluating novel drugs metabolized by CYP3A enzymes and in studying the regulation of human CYP3A gene expression. Furthermore, this system can also be used for generating Tc mice carrying other human metabolic genes.