title: Newly identified CYP2C93 is a functional enzyme in rhesus monkey, but not in cynomolgus monkey.
abstract: Cynomolgus monkey and rhesus monkey are used in drug metabolism studies due to their evolutionary closeness and physiological resemblance to human. In cynomolgus monkey, we previously identified cytochrome P450 (P450 or CYP) 2C76 that does not have a human ortholog and is partly responsible for species differences in drug metabolism between cynomolgus monkey and human. In this study, we report characterization of CYP2C93 cDNA newly identified in cynomolgus monkey and rhesus monkey. The CYP2C93 cDNA contained an open reading frame of 490 amino acids approximately 84-86% identical to human CYP2Cs. CYP2C93 was located in the genomic region, which corresponded to the intergenic region in the human genome, indicating that CYP2C93 does not correspond to any human genes. CYP2C93 mRNA was expressed predominantly in the liver among 10 tissues analyzed. The CYP2C93 proteins heterologously expressed in Escherichia coli metabolized human CYP2C substrates, diclofenac, flurbiprofen, paclitaxel, S-mephenytoin, and tolbutamide. In addition to a normal transcript (SV1), an aberrantly spliced transcript (SV2) lacking exon 2 was identified, which did not give rise to a functional protein due to frameshift and a premature termination codon. Mini gene assay revealed that the genetic variant IVS2-1G>T at the splice site of intron 1, at least partly, accounted for the exon-2 skipping; therefore, this genotype would influence CYP2C93-mediated drug metabolism. SV1 was expressed in 6 of 11 rhesus monkeys and 1 of 8 cynomolgus monkeys, but the SV1 in the cynomolgus monkey was nonfunctional due to a rare null genotype (c.102T>del). These results suggest that CYP2C93 can play roles as a drug-metabolizing enzyme in rhesus monkeys (not in cynomolgus monkeys), although its relative contribution to drug metabolism has yet to be validated.
authors.affiliation: Pharmacokinetics and Bioanalysis Center, Shin Nippon Biomedical Laboratories, Ltd., Kainan, Japan. uno-yasuhiro@snbl.co.jp
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Uno
authors.forename: Shotaro
authors.initials: S
authors.lastname: Uehara
authors.forename: Sakae
authors.initials: S
authors.lastname: Kohara
authors.forename: Kazuhide
authors.initials: K
authors.lastname: Iwasaki
authors.forename: Ryoichi
authors.initials: R
authors.lastname: Nagata
authors.forename: Koichiro
authors.initials: K
authors.lastname: Fukuzaki
authors.forename: Masahiro
authors.initials: M
authors.lastname: Utoh
authors.forename: Norie
authors.initials: N
authors.lastname: Murayama
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yamazaki
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D003001:Cloning, Molecular; D003577:Cytochrome P-450 Enzyme System / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D018076:DNA, Complementary / Q000235:genetics; D005091:Exons / Q000235:genetics; D005260:Female; D015971:Gene Expression Regulation, Enzymologic; D023281:Genomics; D060005:Genotyping Techniques; D006801:Humans; D008252:Macaca fascicularis; D008253:Macaca mulatta; D008297:Male; D008969:Molecular Sequence Data; D005810:Multigene Family / Q000235:genetics; D004364:Pharmaceutical Preparations / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity
chemical_list: D018076:DNA, Complementary; D004364:Pharmaceutical Preparations; D012333:RNA, Messenger; C400322:cytochrome P-450 CYP2C subfamily; D003577:Cytochrome P-450 Enzyme System