title: Trans-chromosomic mice containing a human CYP3A cluster for prediction of xenobiotic metabolism in humans.
abstract: 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.
authors.affiliation: Department of Biomedical Science, Institute of Regenerative Medicine and Biofunction, Graduate School of Medical Science, Tottori University, 86 Nishi-cho, Yonago, Tottori 683-8503, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Kazuki
authors.forename: Kaoru
authors.initials: K
authors.lastname: Kobayashi
authors.forename: Sasitorn
authors.initials: S
authors.lastname: Aueviriyavit
authors.forename: Takeshi
authors.initials: T
authors.lastname: Oshima
authors.forename: Yoshimi
authors.initials: Y
authors.lastname: Kuroiwa
authors.forename: Yasuko
authors.initials: Y
authors.lastname: Tsukazaki
authors.forename: Naoto
authors.initials: N
authors.lastname: Senda
authors.forename: Hiroki
authors.initials: H
authors.lastname: Kawakami
authors.forename: Sumio
authors.initials: S
authors.lastname: Ohtsuki
authors.forename: Satoshi
authors.initials: S
authors.lastname: Abe
authors.forename: Masato
authors.initials: M
authors.lastname: Takiguchi
authors.forename: Hidetoshi
authors.initials: H
authors.lastname: Hoshiya
authors.forename: Naoyo
authors.initials: N
authors.lastname: Kajitani
authors.forename: Shoko
authors.initials: S
authors.lastname: Takehara
authors.forename: Kinya
authors.initials: K
authors.lastname: Kubo
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Terasaki
authors.forename: Kan
authors.initials: K
authors.lastname: Chiba
authors.forename: Kazuma
authors.initials: K
authors.lastname: Tomizuka
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Oshimura
mesh_terms: D000818:Animals; D001189:Aryl Hydrocarbon Hydroxylases / Q000235:genetics / Q000378:metabolism; D015139:Blotting, Southern; D016466:CHO Cells; D002460:Cell Line; D022222:Chromosomes, Artificial, Human; D002897:Chromosomes, Human, Pair 7; D003001:Cloning, Molecular; D006224:Cricetinae; D051544:Cytochrome P-450 CYP3A / Q000235:genetics* / Q000378:metabolism; D003687:Dehydroepiandrosterone / Q000378:metabolism; D005260:Female; D015971:Gene Expression Regulation, Enzymologic; D056426:Genetic Loci; D006801:Humans; D008658:Inactivation, Metabolic; D007422:Intestines / Q000201:enzymology; D008099:Liver / Q000201:enzymology; D051379:Mice; D008813:Mice, Inbred ICR; D008822:Mice, Transgenic; D008861:Microsomes / Q000378:metabolism; D005810:Multigene Family; D014229:Triazolam / Q000493:pharmacokinetics*; D015262:Xenobiotics / Q000378:metabolism*
chemical_list: D015262:Xenobiotics; D014229:Triazolam; D003687:Dehydroepiandrosterone; D001189:Aryl Hydrocarbon Hydroxylases; C104464:CYP3A protein, human; C103123:CYP3A7 protein, human; D051544:Cytochrome P-450 CYP3A