title: Expression of aryl hydrocarbon receptor repressor in normal human tissues and inducibility by polycyclic aromatic hydrocarbons in human tumor-derived cell lines.
abstract: Aryl hydrocarbon receptor repressor (AhRR) has been recently identified as a negative factor that suppresses aryl hydrocarbon receptor (AhR)-mediated transcriptional gene expression. In the present study, the expression level of AhRR in normal human tissues was determined. AhRR mRNA was detected in liver, breast, colon, kidney, lung, bladder, uterus, testis, ovary, and adrenal gland. The expression level in the testis was prominently high. AhRR mRNA was also detected in various human tissue-derived cell lines, HepG2 (hepatocellular carcinoma), MCF-7 (breast carcinoma), LS-180 (colon carcinoma), ACHN (renal carcinoma), A549 (lung carcinoma), HT-1197 (bladder carcinoma), HeLa (cervix of uterus adenocarcinoma), NEC14 (testis embryonal carcinoma), and OMC-3 (ovarian carcinoma). Since the expression level of AhRR mRNA was prominently high in HeLa cells, it is suggested that the high expression level of AhRR might work as a negative factor for the low inducibility of the CYP1 family in HeLa cells. The expression of AhRR mRNA was induced by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) or 3-methylchoranthrene (3-MC) in HepG2, MCF-7, LS-180, and OMC-3 cells, but not in ACHN, A549, HT-1197, HeLa, and NEC14 cells. The responsiveness was similar to the cell-specific inducibility of the CYP1 family. The inducibility of AhRR mRNA by nitropolycyclic aromatic hydrocarbons (NPAHs) as well as their parent PAHs was compared in HepG2 and OMC-3 cells. The chemical-specific inducibility of AhRR was also similar to that of the CYP1 family determined in our previous study. These results indicated that AhRR is also induced in chemical- and cell-specific manners.
authors.affiliation: Division of Drug Metabolism, Faculty of Pharmaceutical Sciences, Kanazawa University, Takara-machi 13-1, Kanazawa 920-0934, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Tsuchiya
authors.forename: Miki
authors.initials: M
authors.lastname: Nakajima
authors.forename: Satsuki
authors.initials: S
authors.lastname: Itoh
authors.forename: Masashi
authors.initials: M
authors.lastname: Iwanari
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Yokoi
mesh_terms: D001189:Aryl Hydrocarbon Hydroxylases / Q000096:biosynthesis / Q000235:genetics; D051792:Basic Helix-Loop-Helix Proteins; D004305:Dose-Response Relationship, Drug; D005260:Female; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects*; D006801:Humans; D008297:Male; D008748:Methylcholanthrene / Q000494:pharmacology; D000072317:Polychlorinated Dibenzodioxins / Q000494:pharmacology; D011084:Polycyclic Aromatic Hydrocarbons / Q000494:pharmacology*; D012333:RNA, Messenger / Q000378:metabolism; D018336:Receptors, Aryl Hydrocarbon / Q000235:genetics / Q000378:metabolism*; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014407:Tumor Cells, Cultured
chemical_list: D001189:Aryl Hydrocarbon Hydroxylases; D051792:Basic Helix-Loop-Helix Proteins; D008748:Methylcholanthrene; D000072317:Polychlorinated Dibenzodioxins; D011084:Polycyclic Aromatic Hydrocarbons; D012333:RNA, Messenger; D018336:Receptors, Aryl Hydrocarbon; D012097:Repressor Proteins; C492162:AHRR protein, human