title: Assessment of human pregnane X receptor involvement in pesticide-mediated activation of CYP3A4 gene.
abstract: Assessment of foreign chemical inducibility on CYP3A4 is necessary to optimize drug therapies. The properties of chemicals such as pesticides, however, are not well investigated. In the present study, properties of various pesticides on human CYP3A4 induction have been tested using HepG2-derived cells stably expressing the CYP3A4 promoter/enhancer (3-1-10 cells) and the human pregnane X receptor (hPXR)-small interfering RNA (siRNA) system. Among the examined pesticides, 13 pesticides were observed to activate the CYP3A4 gene. Surprisingly, pyributicarb was found to increase the CYP3A4 reporter activity at 0.1 to 1 microM more strongly than typical CYP3A4 inducer rifampicin. Expression of hPXR-siRNA clearly diminished the pyributicarb-stimulated CYP3A4 reporter activity in 3-1-10 cells and decreased the endogenous CYP3A4 mRNA levels in HepG2 cells. Pyributicarb caused enhancement of CYP3A4-derived reporter activity in mouse livers introduced with hPXR by adenovirus. These results indicate pyributicarb as a potent activator of CYP3A4 gene, suggesting the existence of pesticides leading to CYP3A4 induction in our environment.
authors.affiliation: Division of Drug Metabolism and Molecular Toxicology, Graduate School of Pharmaceutical Sciences, Tohoku University, Aramaki-aoba 6-3, Aoba-ku, Sendai, Miyagi 980-8578, Japan.
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Matsubara
authors.forename: Wachiraporn
authors.initials: W
authors.lastname: Noracharttiyapot
authors.forename: Takayoshi
authors.initials: T
authors.lastname: Toriyabe
authors.forename: Kouichi
authors.initials: K
authors.lastname: Yoshinari
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Nagata
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Yamazoe
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D051544:Cytochrome P-450 CYP3A; D065607:Cytochrome P-450 Enzyme Inhibitors; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics* / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D005659:Fungicides, Industrial / Q000494:pharmacology*; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D006801:Humans; D015151:Immunoblotting; D007306:Insecticides / Q000494:pharmacology*; D008099:Liver / Q000187:drug effects / Q000473:pathology; D008156:Luciferases / Q000235:genetics / Q000378:metabolism; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D000077297:Pregnane X Receptor; D011285:Pregnenolone Carbonitrile / Q000494:pharmacology; D011401:Promoter Regions, Genetic / Q000235:genetics; D012333:RNA, Messenger / Q000187:drug effects / Q000235:genetics; D034741:RNA, Small Interfering / Q000235:genetics; D011987:Receptors, Steroid / Q000235:genetics* / Q000378:metabolism; D012293:Rifampin / Q000494:pharmacology; D014158:Transcription, Genetic / Q000187:drug effects
chemical_list: D065607:Cytochrome P-450 Enzyme Inhibitors; D005659:Fungicides, Industrial; D007306:Insecticides; D000077297:Pregnane X Receptor; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D011987:Receptors, Steroid; D011285:Pregnenolone Carbonitrile; D003577:Cytochrome P-450 Enzyme System; D008156:Luciferases; D051544:Cytochrome P-450 CYP3A; C510163:CYP3A4 protein, human; D012293:Rifampin